The pathophysiological basis and consequences of fever

The antipyretic effect of the famous classical formula Qingwanzi Pills on a rabbit model and its serum metabolomic study

Qingwanzi Pills (QP) were first mentioned in the "Puji Fang" of the Ming Dynasty, with a history of approximately 600 years. The formula consisted of Gypsum Fibrosum and Indigo Naturalis. It is a famous classical formula with antipyretic effects frequently utilized in ancient China, although our knowledge about the overall antipyretic mechanism of QP remains limited. Therefore, we replicated the fever model in New Zealand rabbits induced by lipopolysaccharide, performed the pharmacodynamic evaluation of QP, identified the differential metabolites among QP groups, and performed pathway enrichment analysis to comparatively analyze the effects of QP on fever-related metabolic pathways by ultra-performance liquid chromatography-mass spectrometry. The results showed that the antipyretic effect of QP was superior to that of each disassembled prescription, with Gypsum Fibrosum primarily contributing to the efficacy, followed by Indigo Naturalis and Junci Medulla. QP had an effective antipyretic effect, which was related to lowering the levels of TNF-α, IL-6, IL-1β, and calcium in rabbit serum, lowering the levels of PGE2 and cAMP in rabbit cerebrospinal fluid, and increasing the level of calcium in rabbit cerebrospinal fluid. A total of 27 endogenous biomarkers were screened by serum metabolomics for the treatment of fever with QP. It is hypothesized that the antipyretic mechanism of QP may be related to regulating α-linolenic acid, sphingolipid, tryptophan, and bile acid metabolism. In summary, QP exhibited a significant antipyretic effect in rabbits with lipopolysaccharide-induced fever.

Implications of inflammatory cell death-PANoptosis in health and disease

Regulated cell death (RCD) pathways, such as pyroptosis, apoptosis, and necroptosis, are essential for maintaining the body's balance, defending against pathogens, and eliminating abnormal cells that could lead to diseases like cancer. Although these pathways operate through distinct mechanisms, recent genetic and pharmacological studies have shown that they can interact and influence each other. The concept of "PANoptosis" has emerged, highlighting the interplay between pyroptosis, apoptosis, and necroptosis, especially during cellular responses to infections. This article provides a concise overview of PANoptosis and its molecular mechanisms, exploring its implications in various diseases. The review focuses on the extensive interactions among different RCD pathways, emphasizing the role of PANoptosis in infections, cytokine storms, inflammatory diseases, and cancer. Understanding PANoptosis is crucial for developing novel treatments for conditions involving infections, sterile inflammations, and cancer.

NK1 receptor mediates cerebral cellular and extracellular morphological changes during the LPS-induced febrile response

Fever elicited by bacterial lypopolyssacharide (LPS) is mediated by pro-inflammatory cytokines, which activate central mediators and regulate the hypothalamic temperature setpoint. This response is often accompanied by morphological changes involving the extracellular matrix, neurons and glial cells, with significant health impacts. The NK1 receptor is involved in the febrile response induced by LPS but its effects over the extracellular matrix in the context of neuroinflammation remain unknown. The present work aims to clarify the extracellular changes associated with NK1 signaling in LPS-induced fever. Male Wistar rats were exposed to LPS intraperitoneally. Experimental groups were pre-treated intracerebroventricularly with the NK1 selective inhibitor SR140333B or saline. Histological changes involving the brain extracellular matrix were evaluated using hematoxylin and eosin, Mason's trichrome, picrosirius, alcian blue, periodic acid Schiff's stains. The expression of matrix metalloproteinase 9 (MMP9) was studied using confocal microscopy. Fever was accompanied by edema, perivascular lymphoplamacytic and neutrophylic infiltration, spongiosis and MMP9 overexpression. SR140333B significantly reduced LPS-induced fever (p < 0.0001), MMP9 overexpression (p < 0.01) and associated histological changes. These results contribute to characterize cerebral extracellular matrix changes associated with LPS-induced fever. Overall, the present work supports a role for NK1 receptor in these neuroinflammatory changes, involving MMP9 overexpression, edema and leukocytic infiltration.

Microglia Caspase11 non-canonical inflammasome drives fever

AIM

Animals exhibit physiological changes designed to eliminate the perceived danger, provoking similar symptoms of fever. However, a high-grade fever indicates poor clinical outcomes. Caspase11 (Casp11) is involved in many inflammatory diseases. Whether Casp11 leads to fever remains unclear. In this study, we investigate the role of the preoptic area of the hypothalamus (PO/AH) microglia Casp11 in fever.

METHODS

We perform experiments using a rat model of LPS-induced fever. We measure body temperature and explore the functions of peripheral macrophages and PO/AH microglia in fever signaling by ELISA, immunohistochemistry, immunofluorescence, flow cytometry, macrophage depletion, protein blotting, and RNA-seq. Then, the effects of macrophages on microglia in a hyperthermic environment are observed in vitro. Finally, adeno-associated viruses are used to knockdown or overexpress microglia Casp11 in PO/AH to determine the role of Casp11 in fever.

RESULTS

We find peripheral macrophages and PO/AH microglia play important roles in the process of fever, which is proved by macrophage and microglia depletion. By RNA-seq analysis, we find Casp11 expression in PO/AH is significantly increased during fever. Co-culture and conditioned-culture simulate the induction of microglia Casp11 activation by macrophages in a non-contact manner. Microglia Casp11 knockdown decreases body temperature, pyrogenic factors, and inflammasome, and vice versa.

CONCLUSION

We report that Casp11 drives fever. Mechanistically, peripheral macrophages transmit immune signals via cytokines to microglia in PO/AH, which activate the Casp11 non-canonical inflammasome. Our findings identify a novel player, the microglia Casp11, in the control of fever, providing an explanation for the transmission and amplification of fever immune signaling.

In Situ Array Microextraction and Metabolic Profiling of Small Extracellular Vesicles to Guide and Monitor Maternal Delivery

The advantages of small extracellular vesicles (sEV) in disease management have become increasingly prominent, with the main challenge lying in meeting the demands of large-scale extraction and high-throughput analysis, a crucial aspect in the realm of precision medicine. To overcome this challenge, an engineered on-plate aptamer array (16×24 spots) is developed for continuous scale-up microextraction of plasma sEV and their in situ metabolic analysis using mass spectrometry. With this integrated array strategy, metabolic profiles of sEV are acquired from the plasma of 274 antenatal or postpartum women, reducing analysis time by half (7.5 h) and sample volume by 95% (only 0.125 µL usage) compared to the traditional suspension method. Moreover, using machine learning algorithms on sEV metabolic profiles, a risk score system is constructed that accurately assesses the need for epidural analgesia during childbirth and the likelihood of post-administration fever. The system, based on admission samples, achieves an impressive 94% accuracy. Furthermore, post-administration fever can be identified from delivery samples, reaching an overall accuracy rate of 88%. This work offers real-time monitoring of the childbirth process that can provide timely guidance for maternal delivery, underscoring the significance of sEV detection in large-scale clinical samples for medicine innovation and advancement.

[Infections and fever]

Fever can be due to infectious or noninfectious causes and results from the body's natural response to exogenous or endogenous pyrogens. Laboratory tests including complete blood count, differential blood count, C‑reactive protein, erythrocyte sedimentation rate and procalcitonin do not have sufficient sensitivity and specificity to definitively detect or rule out an infectious (bacterial, viral, parasitic) cause of fever. Blood cultures should be carried out when bacteremic or septic illnesses are suspected. Fever is not always present in infections and can be absent, especially in older and immunocompromised patients. If fever is suspected, core temperatures should be taken, e.g., rectally, orally or invasively. Depending on the clinical situation, infectious causes must be excluded as the most likely cause of an acutely occurring fever. The investigation of long-standing fever (fever of unknown origin, FUO) can be complex and some infectious diseases should first be ruled out, whereby a syndromic classification often helps to clarify the cause of the fever.

A Systematic Literature Review to Assess Fever Management and the Quality of Targeted Temperature Management in Critically Ill Patients

Targeted temperature management (TTM) has been proposed to reduce mortality and improve neurological outcomes in postcardiac arrest and other critically ill patients. TTM implementation may vary considerably among hospitals, and "high-quality TTM" definitions are inconsistent. This systematic literature review in relevant critical care conditions evaluated the approaches to and definitions of TTM quality with respect to fever prevention and the maintenance of precise temperature control. Current evidence on the quality of fever management associated with TTM in cardiac arrest, traumatic brain injury, stroke, sepsis, and critical care more generally was examined. Searches were conducted in Embase and PubMed (2016 to 2021) following PRISMA guidelines. In total, 37 studies were identified and included, with 35 focusing on postarrest care. Frequently-reported TTM quality outcomes included the number of patients with rebound hyperthermia, deviation from target temperature, post-TTM body temperatures, and number of patients achieving target temperature. Surface and intravascular cooling were used in 13 studies, while one study used surface and extracorporeal cooling and one study used surface cooling and antipyretics. Surface and intravascular methods had comparable rates of achieving target temperature and maintaining temperature. A single study showed that patients with surface cooling had a lower incidence of rebound hyperthermia. This systematic literature review largely identified cardiac arrest literature demonstrating fever prevention with multiple TTM approaches. There was substantial heterogeneity in the definitions and delivery of quality TTM. Further research is required to define quality TTM across multiple elements, including achieving target temperature, maintaining target temperature, and preventing rebound hyperthermia.

Dehydrozaluzanin C- derivative protects septic mice by alleviating over-activated inflammatory response and promoting the phagocytosis of macrophages

Host-directed therapy (HDT) is a new adjuvant strategy that interfere with host cell factors that are required by a pathogen for replication or persistence. In this study, we assessed the effect of dehydrozaluzanin C-derivative (DHZD), a modified compound from dehydrozaluzanin C (DHZC), as a potential HDT agent for severe infection. LPS-induced septic mouse model and Carbapenem resistant Klebsiella pneumoniae (CRKP) infection mouse model was used for testing in vivo. RAW264.7 cells, mouse primary macrophages, and DCs were used for in vitro experiments. Dexamethasone (DXM) was used as a positive control agent. DHZD ameliorated tissue damage (lung, kidney, and liver) and excessive inflammatory response induced by LPS or CRKP infection in mice. Also, DHZD improved the hypothermic symptoms of acute peritonitis induced by CRKP, inhibited heat-killed CRKP (HK-CRKP)-induced inflammatory response in macrophages, and upregulated the proportions of phagocytic cell types in lungs. In vitro data suggested that DHZD decreases LPS-stimulated expression of IL-6, TNF-α and MCP-1 via PI3K/Akt/p70S6K signaling pathway in macrophages. Interestingly, the combined treatment group of DXM and DHZD had a higher survival rate and lower level of IL-6 than those of the DXM-treated group; the combination of DHZD and DXM played a synergistic role in decreasing IL-6 secretion in sera. Moreover, the phagocytic receptor CD36 was increased by DHZD in macrophages, which was accompanied by increased bacterial phagocytosis in a clathrin- and actin-dependent manner. This data suggests that DHZD may be a potential drug candidate for treating bacterial infections.

Causes and outcomes of non-chemotherapy induced neutropenic fever in hospitalized adults: An observational study

Neutropenic fever in adults undergoing chemotherapy for cancer treatment is a medical emergency and has been the focus of numerous studies. However, there is a paucity of data about non-chemotherapy induced neutropenic fever (non-CINF). We retrospectively reviewed 383 adults with neutropenic fever hospitalized at one academic medical center between October 2015 and September 2020 to characterize the frequency, causes, and outcomes of non-CINF. Twenty-six percent of cases of neutropenic fever were non-chemotherapy induced. Among these, the major causes of neutropenia were hematologic malignancy, infection, and rheumatologic disease, and the major causes of fever were infections. Patients with non-CINF had a higher 30-day mortality than those with chemotherapy induced neutropenic fever (25% vs 13%, P = .01). Non-CINF constituted > 25% of neutropenic fever events in hospitalized adults and was associated with a high mortality rate.

Blood transfusion reactions and risk of acute kidney injury and major adverse kidney events

BACKGROUND

Blood transfusion reactions may have a negative impact on organ function. It is unknown whether this association holds true for acute kidney injury (AKI). Therefore, we conducted a cohort study to assess the association between transfusion reactions and the incidence of AKI and major adverse kidney events.

METHODS

In this retrospective cohort study, we included patients who received transfusion of blood products during hospitalization at the Hospital Civil of Guadalajara. We analyzed them according to the development of transfusion reactions, and the aim was to assess the association between transfusion reactions and AKI during long-term follow-up.

RESULTS

From 2017 to 2021, 81,635 patients received a blood product transfusion, and 516 were included in our study. The most common transfusion was red blood cell packaging (50.4%), fresh frozen plasma (28.7%) and platelets (20.9%); of the 516 patients, 129 (25%) had transfusion reactions. Patients who had transfusion reactions were older and had more comorbidities. The most common type of transfusion reaction was allergic reaction (70.5%), followed by febrile nonhemolytic reaction (11.6%) and anaphylactoid reaction (8.5%). Most cases were considered mild. Acute kidney injury was more prevalent among those who had transfusion reactions (14.7%) than among those who did not (7.8%), p =  < 0.01; those with AKI had a higher frequency of diabetes, vasopressors, and insulin use. Transfusion reactions were independently associated with the development of AKI (RR 2.1, p =  < 0.02). Major adverse kidney events were more common in those with transfusion reactions. The mortality rate was similar between subgroups.

CONCLUSION

In our retrospective cohort of patients who received blood product transfusions, 25% experienced transfusion reactions, and this event was associated with a twofold increase in the probability of developing AKI and some of the major adverse kidney events during long follow-up.

The protective effect of breastfeeding on febrile seizures: a systematic review with meta-analysis

Several potential risk factors have been identified in the etiopathogenesis of febrile seizures (FS), including the type and extent of breastfeeding (BF). Given the lack of conclusive data, this study aims to systematically evaluate the evidence on the association between BF and FS. We conducted a systematic review and meta-analysis according to PRISMA guidelines. The search was conducted using descriptors for FS, BF, and formula feeding in MEDLINE, Embase, and Web of Science databases. We included observational studies that compared the incidence of FS between those who had ever breastfed and those who were formula fed. The study protocol was registered on the PROSPERO platform under the number CRD42023474906. A total of 1,893,079 participants from 8 datasets were included. Our main analysis showed no significant association of any type of BF on the incidence of FS compared with formula-fed children (OR: 0.84; CI: 0.67-1.04; I2 = 78%; Cochran's Q = 0.0001), although meta-regression showed that BF was associated with a lower incidence of FS in preterm infants. Our secondary outcome showed a significantly reduced incidence of FS in children who received BF exclusively (OR: 0.80; CI: 0.65-0.99; I2 = 70%; Cochran's Q = 0.02).    Conclusion: There was no significant reduction in the incidence of FS in those who were breastfed compared to formula feeding. However, our meta-regression analysis indicated an association between BF and a lower incidence of FS in preterm infants. Additionally, children who exclusively received BF had a significantly reduced incidence of FS. These findings should be further investigated in prospective cohorts. What is Known: • Breastfeeding can modify risk factors for febrile seizures, such as susceptibility to viral and bacterial infections, micronutrient deficiencies, and low birth weight. • However, studies have shown conflicting results regarding the impact of breastfeeding on febrile seizures. What is New: • When comparing any breastfeeding pattern with no breastfeeding, there is no significant difference in the incidence of febrile seizures. • When comparing exclusive breastfeeding with no breastfeeding, there may be a decrease in the occurrence of febrile seizures.

Heatstroke: a multicenter study in Southwestern China

Background

An increase in Heatstroke cases occurred in southwest China in 2022 due to factors like global warming, abnormal temperature rise, insufficient power supply, and other contributing factors. This resulted in a notable rise in Heatstroke patients experiencing varying degrees of organ dysfunction. This descriptive study aims to analyze the epidemiology and clinical outcomes of Heatstroke patients in the ICU, providing support for standardized diagnosis and treatment, ultimately enhancing the prognosis of Heatstroke.

Methods

A retrospective, multicenter, descriptive analysis was conducted on Heatstroke patients admitted to ICUs across 83 hospitals in southwest China. Electronic medical records were utilized for data collection, encompassing various aspects such as epidemiological factors, onset symptoms, complications, laboratory data, concurrent infections, treatments, and patient outcomes.

Results

The dataset primarily comprised classic heatstroke, with 477 males (55% of total). The patient population had a median age of 72 years (range: 63-80 years). The most common initial symptoms were fever, mental or behavioral abnormalities, and fainting. ICU treatment involved respiratory support, antibiotics, sedatives, and other interventions. Among the 700 ICU admissions, 213 patients had no infection, while 487 were diagnosed with infection, predominantly lower respiratory tract infection. Patients presenting with neurological symptoms initially (n = 715) exhibited higher ICU mortality risk compared to those without neurological symptoms (n = 104), with an odds ratio of 2.382 (95% CI 1.665, 4.870) (p = 0.017).

Conclusion

In 2022, the majority of Heatstroke patients in southwest China experienced classical Heatstroke, with many acquiring infections upon admission to the ICU. Moreover, Heatstroke can result in diverse complications.

Antipyretic effect of inhaled Tetrastigma hemsleyanum polysaccharide on substance and energy metabolism in yeast-induced pyrexia mice via TLR4/NF-κb signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum Diels et Gilg, is one of the perennial evergreen plants with grass vine, which has obvious curative effect on severe infectious diseases. Although Tetrastigma hemleyanum has long been recognized for its capacity of antipyretic and antitoxic, its specific mechanism is unknown.

AIM OF THE STUDY

To evaluate the antipyretic effect of Tetrastigma hemleyanum polysaccharide (THP) on mice with dry yeast-induced fever, and to explore its specific antipyretic mechanism.

METHODS

In this study, THP was administered by aerosol in febrile mice. The rectal temperatures of treated animals were monitored at different time points. Histopathological evaluation and various inflammatory indexes were used to assess inflammatory damage. The concentration variations of the central neurotransmitter, endocrine system, substance and energy metabolism indicators were measured to explore the physiological mechanism. Quantitative real-time PCR, Western bolt and Immunohistochemistry were performed to identify the correlation between antipyretic and TLR4/NF-κB signaling pathway.

RESULTS

THP reduced the body temperature of febrile mice induced by dry yeast, as well as the levels of thermogenic cytokines and downregulated the contents of thermoregulatory mediators. THP alleviated the pathological damage of liver and hypothalamus caused by fever. In addition, THP decreased the secretion of thyroid hormone, substance and energy metabolism related indicators. Furthermore, THP significantly suppressed TLR4/NF-κB signaling pathway-related indicators.

CONCLUSIONS

In conclusion, our results suggest that inhaled THP exerts antipyretic effect by mediating the thermoregulatory mediator, decreasing the content of pyrogenic factors to lower the body temperature, and eventually restoring the high metabolic level in the body to normal via inhibiting TLR4/NF-κB signaling pathway. The study provides a reasonable pharmacodynamic basis for the treatment of polysaccharide in febrile-related diseases.

Kaempferol 3-O-Rutinoside, a Flavone Derived from Tetrastigma hemsleyanum Diels et Gilg, Reduces Body Temperature through Accelerating the Elimination of IL-6 and TNF-α in a Mouse Fever Model

Fever is a serious condition that can lead to various consequences ranging from prolonged illness to death. Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) has been used for centuries to treat fever, but the specific chemicals responsible for its antipyretic effects are not well understood. This study aimed to isolate and identify the chemicals with antipyretic bioactivity in T. hemsleyanum extracts and to provide an explanation for the use of T. hemsleyanum as a Chinese herbal medicine for fever treatment. Our results demonstrate that kaempferol 3-rutinoside (K3OR) could be successfully isolated and purified from the roots of T. hemsleyanum. Furthermore, K3OR exhibited a significant reduction in rectal temperature in a mouse model of fever. Notably, a 4 μM concentration of K3OR showed more effective antipyretic effects than ibuprofen and acetaminophen. To explore the underlying mechanism, we conducted an RNA sequencing analysis, which revealed that PXN may act as a key regulator in the fever process induced by lipopolysaccharide (LPS). In the mouse model of fever, K3OR significantly promoted the secretion of IL-6 and TNF-α during the early stage in the LPS-treated group. However, during the middle to late stages, K3OR facilitated the elimination of IL-6 and TNF-α in the LPS-treated group. Overall, our study successfully identified the chemicals responsible for the antipyretic bioactivity in T. hemsleyanum extracts, and it answered the question as to why T. hemsleyanum is used as a traditional Chinese herbal medicine for treating fever. These findings contribute to a better understanding of the therapeutic potential of T. hemsleyanum in managing fever, and they provide a basis for further research and development in this field.

The protective effects of Zingiber zerumbet rhizome against fevers in rats

The Zingiber zerumbet rhizomes are traditionally used to treat fever, and the in vitro inhibitory effect of ethyl acetate extract from Zingiber zerumbet rhizomes (EAEZZR) against DENV2 NS2B/NS3 (two non-structural proteins, NS2 and NS3 of dengue virus type 2) has been reported earlier. This study was carried out to establish an acute toxicity profile and evaluate the anti-fever (anti-pyretic) activities of EAEZZR in yeast-induced fever in rats. The major compound of EAEZZR, zerumbone, was isolated using chromatographic methods including column chromatography (CC) and preparative thin-layer chromatography (PTLC). Additionally, the structure of zerumbone was elucidated using nuclear magnetic resonance (NMR), liquid chromatography mass spectrometer-ion trap-time of flight (LCMS-IT-TOF), infrared (IR), and ultraviolet (UV) spectroscopy. The toxicity of EAEZZR was evaluated using Organization for Economic Cooperation and Development Test Guideline 425 (OECD tg-425) with minor modifications at concentrations EAEZZR of 2000 mg/kg, 3000 mg/kg, and 5000 mg/kg. Anti-fever effect was determined by yeast-induced fever (pyrexia) in rats. The acute toxicity study showed that EAEZZR is safe at the highest 5000 mg/kg body weight dose in Sprague Dawley rats. Rats treated with EAEZZR at doses of 125, 250, and 500 mg/kg exhibited a significant reduction in rectal temperature (TR) in the first 1 h. EAEZZR at the lower dose of 125 mg/kg showed substantial potency against yeast-induced fever for up to 2 h compared to 0 h in controls. A significant reduction of TR was observed in rats treated with standard drug aspirin in the third through fourth hours. Based on the present findings, ethyl acetate extract of Zingiber zerumbet rhizomes could be considered safe up to the dose of 5000 mg/kg, and the identification of active ingredients of Zingiber zerumbet rhizomes may allow their use in the treatment of fever with dengue virus infection.

Systematic Literature Review of the Association of Fever and Elevated Temperature with Outcomes in Critically Ill Adult Patients

Although most commonly associated with infection, elevated temperature and fever also occur in a variety of critically ill populations. Prior studies have suggested that fever and elevated temperature may be detrimental to critically ill patients and can lead to poor outcomes, but the evidence surrounding the association of fever with outcomes is rapidly evolving. To broadly assess potential associations of elevated temperature and fever with outcomes in critically ill adult patients, we performed a systematic literature review focusing on traumatic brain injury, stroke (ischemic and hemorrhagic), cardiac arrest, sepsis, and general intensive care unit (ICU) patients. Searches were conducted in Embase® and PubMed® from 2016 to 2021, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including dual-screening of abstracts, full texts, and extracted data. In total, 60 studies assessing traumatic brain injury and stroke (24), cardiac arrest (8), sepsis (22), and general ICU (6) patients were included. Mortality, functional, or neurological status and length of stay were the most frequently reported outcomes. Elevated temperature and fever were associated with poor clinical outcomes in patients with traumatic brain injury, stroke, and cardiac arrest but not in patients with sepsis. Although a causal relationship between elevated temperature and poor outcomes cannot be definitively established, the association observed in this systematic literature review supports the concept that management of elevated temperature may factor in avoidance of detrimental outcomes in multiple critically ill populations. The analysis also highlights gaps in our understanding of fever and elevated temperature in critically ill adult patients.

The Effect of Body Temperature Changes on the Course of Treatment in Patients With Pneumonia and Sepsis: Results of an Observational Study

BACKGROUND

Traditionally, patients who are critically ill with infection and fever have been treated with antipyretics or even physically cooled. Presumed benefits of the reduction of body temperature are mostly based on decreased metabolic demands. However, it has been shown that decreasing body temperature in patients who are critically ill is not associated with improvement in treatment outcomes. Additionally, there is some data to support the use of temperature modulation (therapeutic hyperthermia) as an adjuvant treatment strategy in patients with infection.

OBJECTIVE

This study aims to determine the effect of body temperature on the course of intensive care unit (ICU) treatment of patients who are mechanically ventilated with pneumonia, sepsis, and positive tracheal aspirates on admission.

METHODS

We performed a single-center retrospective study. Core body temperature was measured in all patients. We analyzed associations between average temperatures in the first 48 hours after admission to ICU and ICU treatment parameters. Additionally, patients were divided into three groups: patients with negative tracheal aspirates 1 week after ICU admission (P-N group), patients with a different pathogen in tracheal aspirates 1 week after ICU admission (P-HAP group), and patients with a persisting pathogen in tracheal aspirates 1 week after ICU admission (P-P group). Differences in body temperature and interventions aimed at temperature modulation were determined.

RESULTS

We observed a significantly higher average temperature in the first 48 hours after admission to ICU in patients who survived to hospital discharge compared to nonsurvivors (mean 37.2 °C, SD 1 °C vs mean 36.9 °C, SD 1.6 °C; P=.04). We observed no associations between average temperatures in the first 48 hours after ICU admission and days of mechanical ventilation in the first 7 days of treatment (ρ=-0.090; P=.30), the average maximum daily requirement for noradrenaline in the first 7 days of treatment (ρ=-0.029; P=.80), average maximum FiO2 in the first 7 days of ICU treatment (ρ=0.040; P=.70), and requirement for renal replacement therapy in the first 7 days of ICU treatment (mean 37.3 °C, SD 1.4 °C vs mean 37.0 °C, SD 1.3 °C; P=.23). In an additional analysis, we observed a significantly greater use of paracetamol in the P-N group (mean 1.0, SD 1.1 g vs mean 0.4, SD 0.7 g vs mean 0.4, SD 0.8 g; P=.009), a trend toward greater use of active cooling in the first 24 hours after ICU admission in the P-N group (n=11, 44% vs n=14, 33.3% vs n=16, 32%; P=.57), and no other significant differences in parameters of ICU treatment between patient groups.

CONCLUSIONS

We observed better survival in patients who developed higher body temperatures in the first 48 hours after admission to the ICU; however, we observed no changes in other treatment parameters. Similarly, we observed greater use of paracetamol in patients with negative tracheal aspirates 1 week after ICU admission. Our results support the strategy of temperature tolerance in patients who are intubated with pneumonia and sepsis.

NINJ1 mediates inflammatory cell death, PANoptosis, and lethality during infection conditions and heat stress

Innate immunity provides the first line of defense through multiple mechanisms, including pyrogen production and cell death. While elevated body temperature during infection is beneficial to clear pathogens, heat stress (HS) can lead to inflammation and pathology. Links between pathogen exposure, HS, cytokine release, and inflammation have been observed, but fundamental innate immune mechanisms driving pathology during pathogen exposure and HS remain unclear. Here, we use multiple genetic approaches to elucidate innate immune pathways in infection or LPS and HS models. Our results show that bacteria and LPS robustly increase inflammatory cell death during HS that is dependent on caspase-1, caspase-11, caspase-8, and RIPK3 through the PANoptosis pathway. Caspase-7 also contributes to PANoptosis in this context. Furthermore, NINJ1 is an important executioner of this cell death to release inflammatory molecules, independent of other pore-forming executioner proteins, gasdermin D, gasdermin E, and MLKL. In an in vivo HS model, mortality is reduced by deleting NINJ1 and fully rescued by deleting key PANoptosis molecules. Our findings suggest that therapeutic strategies blocking NINJ1 or its upstream regulators to prevent PANoptosis may reduce the release of inflammatory mediators and benefit patients.

Perspective: "Current understanding of NADs dynamics and mechanisms of Disease"

Chromatin architecture is essential for gene regulation, and multiple levels of the 3D chromatin organization exhibit dynamic changes during organismal development and cell differentiation. Heterochromatin, termed compartment B in Hi-C datasets, is a phase-separating gene-silencing form of chromatin, preferentially located at the two nuclear sites, nuclear (lamina-associate chromatin domains, LADs) and nucleoli (nucleoli-associated chromatin domains, NADs) peripheries. LADs and NADs contain both interchangeable and location-specific chromatin domains. Recent studies suggest striking dynamics in LADs and NADs during the differentiation of embryonic stem cells into neural progenitors and neurons. Here we discuss recent advances in understanding NADs changes during neuronal differentiation and future questions on how NADs integrity can contribute to healthy neurodevelopment and neurodevelopment diseases.

Body temperature in the acute phase and clinical outcomes after acute ischemic stroke

BACKGROUND

This study aimed to examine whether post-stroke early body temperature is associated with neurological damage in the acute phase and functional outcomes at three months.

METHODS

We included 7,177 patients with acute ischemic stroke within 24 h of onset. Axillary temperature was measured daily in the morning for seven days. Mean body temperature was grouped into five quintiles (Q1: 35.1‒36.5°C, Q2: 36.5‒36.7°C, Q3: 36.7‒36.8°C, Q4: 36.8‒37.1°C, and Q5: 37.1‒39.1°C). Clinical outcomes included neurological improvement during hospitalization and poor functional outcome (modified Rankin scale score, 3-6) at three months. A logistic regression analysis was performed to evaluate the association between body temperature and clinical outcomes.

RESULTS

The patient's mean (SD) age was 70.6 (12.3) years, and 35.7% of patients were women. Mean body temperature was significantly associated with less neurological improvement from Q2 (odds ratios [95% confidence interval], 0.77 [0.65-0.99] vs. Q1) to Q5 (0.33 [0.28-0.40], P for trend <0.001) even after adjusting for potential confounders, including baseline neurological severity, C-reactive protein levels, and post-stroke acute infections. The multivariable-adjusted risk of poor functional outcome linearly increased from Q2 (1.36 [1.03-1.79]) to Q5 (6.44 [5.19-8.96], P for trend <0.001). These associations were maintained even in the analyses excluding patients with acute infectious diseases. Multivariable-adjusted risk of poor functional outcome was higher in patients with early body temperature elevation on days 1-3 and with longer duration with body temperature >37.0°C.

CONCLUSIONS

Post-stroke early high body temperature is independently associated with unfavorable outcomes following acute ischemic stroke.

The Dangers of Acetaminophen for Neurodevelopment Outweigh Scant Evidence for Long-Term Benefits

Based on available data that include approximately 20 lines of evidence from studies in laboratory animal models, observations in humans, correlations in time, and pharmacological/toxicological considerations, it has been concluded without reasonable doubt and with no evidence to the contrary that exposure of susceptible babies and children to acetaminophen (paracetamol) induces many, if not most, cases of autism spectrum disorder (ASD). However, the relative number of cases of ASD that might be induced by acetaminophen has not yet been estimated. Here, we examine a variety of evidence, including the acetaminophen-induced reduction of social awareness in adults, the prevalence of ASD through time, and crude estimates of the relative number of ASD cases induced by acetaminophen during various periods of neurodevelopment. We conclude that the very early postpartum period poses the greatest risk for acetaminophen-induced ASD, and that nearly ubiquitous use of acetaminophen during early development could conceivably be responsible for the induction in the vast majority, perhaps 90% or more, of all cases of ASD. Despite over a decade of accumulating evidence that acetaminophen is harmful for neurodevelopment, numerous studies demonstrate that acetaminophen is frequently administered to children in excess of currently approved amounts and under conditions in which it provides no benefit. Further, studies have failed to demonstrate long-term benefits of acetaminophen for the pediatric population, leaving no valid rationale for continued use of the drug in that population given its risks to neurodevelopment.

Current State of Knowledge on the Definition, Pathophysiology, Etiology, Outcomes, and Management of Fever in the Intensive Care Unit

Fever-an elevated body temperature-is a prominent feature of a wide range of disease conditions and is a common finding in intensive care, affecting up to 70% of patients in the intensive care unit (ICU). The causes of fever in the ICU are multifactorial, and it can be due to a number of infective and noninfective etiologies. The production of fever represents a complex physiological, adaptive host response that is beneficial for host defense and survival but can be maladaptive and harmful if left unabated. Despite any cause, fever is associated with a wide range of cellular, local, and systemic effects, including multiorgan dysfunction, systemic inflammation, poor neurological recovery, and an increased risk of mortality. This narrative review presents the current state-of-the-art knowledge on the definition, pathophysiology, etiology, and outcomes of fever in the ICU and highlights evidence-based findings regarding the management of fever in the intensive care setting.

Traumatic brain injury extending to the striatum alters autonomic thermoregulation and hypothalamic monoamines in recovering rats

The brain cortex is the structure that is typically injured in traumatic brain injury (TBI) and is anatomically connected with other brain regions, including the striatum and hypothalamus, which are associated in part with motor function and the regulation of body temperature, respectively. We investigated whether a TBI extending to the striatum could affect peripheral and core temperatures as an indicator of autonomic thermoregulatory function. Moreover, it is unknown whether thermal modulation is accompanied by hypothalamic and cortical monoamine changes in rats with motor function recovery. The animals were allocated into three groups: the sham group (sham), a TBI group with a cortical contusion alone (TBI alone), and a TBI group with an injury extending to the dorsal striatum (TBI + striatal injury). Body temperature and motor deficits were evaluated for 20 days post-injury. On the 3rd and 20th days, rats were euthanized to measure the serotonin (5-HT), noradrenaline (NA), and dopamine (DA) levels using high-performance liquid chromatography (HPLC). We observed that TBI with an injury extending to the dorsal striatum increased core and peripheral temperatures. These changes were accompanied by a sustained motor deficit lasting for 14 days. Furthermore, there were notable increases in NA and 5-HT levels in the brain cortex and hypothalamus both 3 and 20 days after injury. In contrast, rats with TBI alone showed no changes in peripheral temperatures and achieved motor function recovery by the 7th day post-injury. In conclusion, our results suggest that TBI with an injury extending to the dorsal striatum elevates both core and peripheral temperatures, causing a delay in functional recovery and increasing hypothalamic monoamine levels. The aftereffects can be attributed to the injury site and changes to the autonomic thermoregulatory functions.

Adverse Effect of Neurogenic, Infective, and Inflammatory Fever on Acutely Injured Human Spinal Cord

This study aims to determine the effect of neurogenic, inflammatory, and infective fevers on acutely injured human spinal cord. In 86 patients with acute, severe traumatic spinal cord injuries (TSCIs; American Spinal Injury Association Impairment Scale (AIS), grades A-C) we monitored (starting within 72 h of injury, for up to 1 week) axillary temperature as well as injury site cord pressure, microdialysis (MD), and oxygen. High fever (temperature ≥38°C) was classified as neurogenic, infective, or inflammatory. The effect of these three fever types on injury-site physiology, metabolism, and inflammation was studied by analyzing 2864 h of intraspinal pressure (ISP), 1887 h of MD, and 840 h of tissue oxygen data. High fever occurred in 76.7% of the patients. The data show that temperature was higher in neurogenic than non-neurogenic fever. Neurogenic fever only occurred with injuries rostral to vertebral level T4. Compared with normothermia, fever was associated with reduced tissue glucose (all fevers), increased tissue lactate to pyruvate ratio (all fevers), reduced tissue oxygen (neurogenic + infective fevers), and elevated levels of pro-inflammatory cytokines/chemokines (infective fever). Spinal cord metabolic derangement preceded the onset of infective but not neurogenic or inflammatory fever. By considering five clinical characteristics (level of injury, axillary temperature, leukocyte count, C-reactive protein [CRP], and serum procalcitonin [PCT]), it was possible to confidently distinguish neurogenic from non-neurogenic high fever in 59.3% of cases. We conclude that neurogenic, infective, and inflammatory fevers occur commonly after acute, severe TSCI and are detrimental to the injured spinal cord with infective fever being the most injurious. Further studies are required to determine whether treating fever improves outcome. Accurately diagnosing neurogenic fever, as described, may reduce unnecessary septic screens and overuse of antibiotics in these patients.

Trade-Offs among Immune Mechanisms: Bacterial-Challenged Spodoptera frugiperda Larvae Reduce Nodulation Reactions during Behavioral Fever

Insect innate immunity is composed of cellular and humoral reactions, the former acting via circulating hemocytes and the latter via immune signaling that lead to the production of antimicrobial peptides and phenol oxidase-driven melanization. Cellular immunity involves direct interactions between circulating hemocytes and invaders; it includes internalization and killing microbes (phagocytosis) and formation of bacterial-laden microaggregates which coalesce into nodules that are melanized and attached to body walls or organs. Nodulation can entail investing millions of hemocytes which must be replaced. We hypothesized that biologically costly hemocyte-based immunity is traded off for behavioral fevers in infected larvae of fall armyworms, Spodoptera frugiperda, that were allowed to fever. We tested our hypothesis by infecting larvae with the Gram-negative bacterium, Serratia marcescens, placing them in thermal gradients (TGs) and recording their selected body temperatures. While control larvae selected about 30 °C, the experimental larvae selected up 41 °C. We found that 4 h fevers, but not 2, 6 or 24 h fevers, led to increased larval survival. Co-injections of S. marcescens with the prostaglandin (PG) biosynthesis inhibitor indomethacin (INDO) blocked the fevers, which was reversed after co-injections of SM+INDO+Arachidonic acid, a precursor to PG biosynthesis, confirming that PGs mediate fever reactions. These and other experimental outcomes support our hypothesis that costly hemocyte-based immunity is traded off for behavioral fevers in infected larvae under appropriate conditions.

Temperature control in sepsis

Fever can be viewed as an adaptive response to infection. Temperature control in sepsis is aimed at preventing potential harms associated with high temperature (tachycardia, vasodilation, electrolyte and water loss) and therapeutic hypothermia may be aimed at slowing metabolic activities and protecting organs from inflammation. Although high fever (>39.5°C) control is usually performed in critically ill patients, available cohorts and randomized controlled trials do not support its use to improve sepsis prognosis. Finally, both spontaneous and therapeutic hypothermia are associated with poor outcomes in sepsis.

Alignment of multiple metabolomics LC-MS datasets from disparate diseases to reveal fever-associated metabolites

Acute febrile illnesses are still a major cause of mortality and morbidity globally, particularly in low to middle income countries. The aim of this study was to determine any possible metabolic commonalities of patients infected with disparate pathogens that cause fever. Three liquid chromatography-mass spectrometry (LC-MS) datasets investigating the metabolic effects of malaria, leishmaniasis and Zika virus infection were used. The retention time (RT) drift between the datasets was determined using landmarks obtained from the internal standards generally used in the quality control of the LC-MS experiments. Fitted Gaussian Process models (GPs) were used to perform a high level correction of the RT drift between the experiments, which was followed by standard peakset alignment between the samples with corrected RTs of the three LC-MS datasets. Statistical analysis, annotation and pathway analysis of the integrated peaksets were subsequently performed. Metabolic dysregulation patterns common across the datasets were identified, with kynurenine pathway being the most affected pathway between all three fever-associated datasets.

Bupleurum chinense exerts a mild antipyretic effect on LPS-induced pyrexia rats involving inhibition of peripheral TNF-α production

ETHNOPHARMACOLOGICAL RELEVANCE

Bupleuri Radix, the dried roots of Bupleurum chinense DC. (BC) or Bupleurum scorzonerifolium Willd., is one of the most frequently used traditional Chinese medicines. As the species in Xiao-Chai-Hu decoction, BC has been used as an antipyretic medicine with a long history. However, its antipyretic characteristics and underlying mechanism(s) remain unclear.

AIM OF THE STUDY

To elucidate the antipyretic characteristics and mechanism(s) of BC used in its traditional way.

METHODS

The water extract of BC (BCE) was prepared according to the traditional decocting mode. Murine fever and endotoxemia models were induced by intravenous injection of lipopolysaccharide (LPS). In vitro complement activation assay and the levels of TNF-α, IL-6, IL-1β, and C5a were determined by ELISA.

RESULTS

BCE exerted a confirmed but mild antipyretic effect on LPS-induced fever of rat. In vitro, it significantly lowered LPS-elevated TNF-α in the supernatant of rat complete blood cells and THP-1 cells, but failed to decrease IL-6 and IL-1β. In murine endotoxemia models, BCE markedly decreased serum TNF-α, but had no impact on IL-6 and IL-1β. BCE also restricted complement activation in vitro and in vivo. Nevertheless, the mixture of saikosaponin A and D could not suppress supernatant TNF-α of monocytes and serum TNF-α of endotoxemia mice.

CONCLUSIONS

The present study dissects the peripheral mechanism for the antipyretic effect of BC used in the traditional way. Our findings indicate that BCE directly suppresses monocyte-produced TNF-α, thus decreasing circulating TNF-α, which may be responsible for its mild but confirmed antipyretic action.

Assessment of Pain and Inflammation in Domestic Animals Using Infrared Thermography: A Narrative Review

Pain assessment in domestic animals has gained importance in recent years due to the recognition of the physiological, behavioral, and endocrine consequences of acute pain on animal production, welfare, and animal model validity. Current approaches to identifying acute pain mainly rely on behavioral-based scales, quantifying pain-related biomarkers, and the use of devices monitoring sympathetic activity. Infrared thermography is an alternative that could be used to correlate the changes in the superficial temperature with other tools and thus be an additional or alternate acute pain assessment marker. Moreover, its non-invasiveness and the objective nature of its readout make it potentially very valuable. However, at the current time, it is not in widespread use as an assessment strategy. The present review discusses scientific evidence for infrared thermography as a tool to evaluate pain, limiting its use to monitor acute pain in pathological processes and invasive procedures, as well as its use for perioperative monitoring in domestic animals.

Protective effect of the novel cyclic peptide ASK0912 on mice with sepsis induced by Acinetobacter baumannii

BACKGROUND

Sepsis has become a global health concern owing to its increasing incidence and high mortality rate. In the present study, we investigated a novel drug candidate ASK0912 on its protective effects in mice with Acinetobacter baumannii 20-1-induced sepsis, and studied the related mechanisms.

MATERIAL AND METHODS

To analyze the protective effect of ASK0912 on septic mice, survival rates, body temperature, organ and blood bacterial loads, white blood cell and platelet counts, organ damage, and cytokine levels were determined.

RESULTS

ASK0912 remarkably increased the survival rate of mice with sepsis induced by A. baumannii 20-1 at a low dose of 0.6 mg/kg. Rectal temperature measurements showed that ASK0912 treatment prevented the body temperature decrease of septic mice to some extent. Treatment with ASK0912 can notably reduce the organ and blood bacterial loads and alleviate platelet count reduction due to sepsis. ASK0912 attenuated organ damage, including reduced levels of total bile acids, urea, and creatinine, aggregation of inflammatory cells, and mitigation of structural changes in septic mice, as demonstrated by biochemical analysis and hematoxylin & eosin staining. Additionally, multiplex assay showed that abnormally increased cytokine levels (IL-1β, IL-3, IL-5, IL-6, IL-10, IL-13, MCP-1, RANTES, KC, MIP-1α, MIP-1β, and G-CSF) in septic mice decreased after ASK0912 treatment.

CONCLUSIONS

ASK0912 can not only improve the survival rate, hypothermia, lower the bacterial loads in the organs and blood, but also alleviate the pathophysiological manifestations such as intravascular coagulation abnormalities, organ damages, and immune system disorder of sepsis mice induced by A. baumannii 20-1.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis Syndrome and Syndrome of Unexplained Recurrent Fevers in Children and Adults

Children and adults with autoinflammatory disorders, who often experience recurrent fevers, rashes, cold-induced symptoms, conjunctivitis, lymphadenopathy, recurrent infections, aphthous stomatitis, and abnormal blood cell counts, may present to the allergist/immunologist because the symptoms mimic allergies and disorders of immunity. In recent years, there has been increased recognition of non-monogenic autoinflammatory disorders, including periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome and syndrome of undifferentiated recurrent fevers. For many clinical practitioners, the natural history, diagnostic criteria, differential diagnoses, and preferred therapies remain challenging because of the presumed rarity of patients and the evolving field of autoinflammation. Here, we aim to provide a practical framework for the clinical allergist/immunologist to evaluate and treat this patient population.

Critical illness aspects of heatstroke: A hot topic

Heatstroke represents the most severe end of the heat illness spectrum, and is increasingly seen in those undergoing exercise or exertion ('exertional heatstroke') and those exposed to high ambient temperatures, for example in heatwaves ('classical heatstroke'). Both forms may be associated with significant thermal injury, leading to organ dysfunction and the need for admission to an intensive care unit. The process may be exacerbated by translocation of bacteria or endotoxin through an intestinal wall rendered more permeable by the hyperthermia. This narrative review highlights the importance of early diagnosis, rapid cooling and effective management of complications. It discusses the incidence, clinical features and treatment of heatstroke, and discusses the possible role of intestinal permeability and advances in follow-up and recovery of this condition. Optimum treatment involves an integrated input from prehospital, emergency department and critical care teams, along with follow-up by rehabilitation teams and, if appropriate, sports or clinical physiologists.

Changes in Body Temperature Patterns Are Predictive of Mortality in Septic Shock: An Observational Study

Biological rhythms are important regulators of immune functions. In intensive care unit (ICU), sepsis is known to be associated with rhythm disruption. Our objectives were to determine factors associated with rhythm disruption of the body temperature and to assess the relationship between temperature and mortality in septic shock patients; In a cohort of septic shock, we recorded body temperature over a 24-h period on day 2 after ICU admission. For each patient, the temperature rhythmicity was assessed by defining period and amplitude, and the adjusted average (mesor) of the temperature by sinusoidal regression and cosinor analysis. Analyses were performed to assess factors associated with the three temperature parameters (period, amplitude, and mesor) and mortality. 162 septic shocks were enrolled. The multivariate analysis demonstrates that the period of temperature was associated with gender (women, coefficient -2.2 h, p = 0.031) and acetaminophen use (coefficient -4.3 h, p = 0.002). The mesor was associated with SOFA score (coefficient -0.05 °C per SOFA point, p = 0.046), procalcitonin (coefficient 0.001 °C per ng/mL, p = 0.005), and hydrocortisone use (coefficient -0.5 °C, p = 0.002). The amplitude was associated with the dialysis (coefficient -0.5 °C, p = 0.002). Mortality at day 28 was associated with lower mesor (adjusted hazard ratio 0.50, 95% CI 0.28 to 0.90; p = 0.02), and higher amplitude (adjusted hazard ratio 5.48, 95% CI 1.66 to 18.12; p = 0.005) of temperature. Many factors, such as therapeutics, influence the body temperature during septic shock. Lower mesor and higher amplitude were associated with mortality and could be considered prognostic markers in ICU. In the age of artificial intelligence, the incorporation of such data in an automated scoring alert could compete with physicians to identify high-risk patients during septic shock.

Hypothermia or hyperthermia, which is associated with patient outcomes in critically ill children with sepsis? -A retrospective study

OBJECTIVES

In the early stage of sepsis, identifying high-risk paediatric patients with a poor prognosis and providing timely and adequate treatment are critical. This study aimed to evaluate the effect of average body temperature within 24 hours of admission on the short-term prognosis of paediatric patients with sepsis.

DESIGN

A retrospective cohort study.

SETTING

A single-centre, tertiary care hospital in China, containing patient data from 2010 to 2018.

PARTICIPANTS

1144 patients with sepsis were included.

INTERVENTION

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

The main outcome measure was in-hospital mortality, which was defined as death from any cause during hospitalisation. The secondary outcome was the length of hospital stay.

RESULTS

The LOWESS method showed a roughly 'U'-shaped relationship between body temperature on the first day and in-hospital mortality. Multivariate logistic regression showed that severe hypothermia (OR 14.72, 95% CI 4.84 to 44.75), mild hypothermia (OR 3.71, 95% CI 1.26 to 10.90), mild hyperthermia (OR 3.41, 95% CI 1.17 to 9.90) and severe hyperthermia (OR 5.15, 95% CI 1.84 to 14.43) were independent risk factors for in-hospital mortality. Compared with other variables, the Wald χ² value of temperature on the first day minus the degree of freedom was the highest.

CONCLUSIONS

Whether hypothermic or hyperthermic, the more abnormal the temperature on the first day is, the higher the risk of in-hospital death in children with sepsis.

A Novel Vaccine Strategy to Prevent Cytauxzoonosis in Domestic Cats

Cytauxzoonosis is caused by Cytauxzoon felis (C. felis), a tick-borne parasite that causes severe disease in domestic cats in the United States. Currently, there is no vaccine to prevent this fatal disease, as traditional vaccine development strategies have been limited by the inability to culture this parasite in vitro. Here, we used a replication-defective human adenoviral vector (AdHu5) to deliver C. felis-specific immunogenic antigens and induce a cell-mediated and humoral immune response in cats. Cats (n = 6 per group) received either the vaccine or placebo in two doses, 4 weeks apart, followed by experimental challenge with C. felis at 5 weeks post-second dose. While the vaccine induced significant cell-mediated and humoral immune responses in immunized cats, it did not ultimately prevent infection with C. felis. However, immunization significantly delayed the onset of clinical signs and reduced febrility during C. felis infection. This AdHu5 vaccine platform shows promising results as a vaccination strategy against cytauxzoonosis.

The traditional use of Southern African medicinal plants to alleviate fever and their antipyretic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Multiple plant species are used traditionally in southern Africa to treat fever. This review summarises the traditional use, highlights promising plant species and focuses on validation studies to highlight future areas of research.

AIM OF THE STUDY

This study aimed to critically review the use of southern African plants to alleviate fever. Additionally, an examination of research into those plants was undertaken to highlight gaps in the literature with the aim of stimulating further research in this field.

MATERIALS AND METHODS

Ethnobotanical books, reviews and primary research studies were searched to identify plant species traditionally used to treat fever in southern Africa and to summarise the current knowledge and identify areas requiring further research. This study was non-biased and did not have any taxonomic preferences, nor did it favour any southern African healing systems over the others.

RESULTS

The traditional therapeutic uses of 203 southern African plant species to alleviate fever were recorded. Leaves and roots/bulbs/rhizomes were the most commonly used plant part, and they were most commonly prepared as decoctions or infusions and consumed orally. Notably, only twenty-two species (∼11% of the identified species) have been scientifically evaluated for antipyretic properties, with substantially fewer mechanistic studies evident.

CONCLUSIONS

Despite the availability of ethnobotanical records, the antipyretic properties of southern African medicinal plants are poorly reported. Indeed, the efficacy of most plants is yet to be verified and very few mechanistic studies are available.

Thermoneutral housing shapes hepatic inflammation and damage in mouse models of non-alcoholic fatty liver disease

Introduction

Inflammation is a common unifying factor in experimental models of non-alcoholic fatty liver disease (NAFLD) progression. Recent evidence suggests that housing temperature-driven alterations in hepatic inflammation correlate with exacerbated hepatic steatosis, development of hepatic fibrosis, and hepatocellular damage in a model of high fat diet-driven NAFLD. However, the congruency of these findings across other, frequently employed, experimental mouse models of NAFLD has not been studied.

Methods

Here, we examine the impact of housing temperature on steatosis, hepatocellular damage, hepatic inflammation, and fibrosis in NASH diet, methionine and choline deficient diet, and western diet + carbon tetrachloride experimental models of NAFLD in C57BL/6 mice.

Results

We show that differences relevant to NAFLD pathology uncovered by thermoneutral housing include: (i) augmented NASH diet-driven hepatic immune cell accrual, exacerbated serum alanine transaminase levels and increased liver tissue damage as determined by NAFLD activity score; (ii) augmented methionine choline deficient diet-driven hepatic immune cell accrual and increased liver tissue damage as indicated by amplified hepatocellular ballooning, lobular inflammation, fibrosis and overall NAFLD activity score; and (iii) dampened western diet + carbon tetrachloride driven hepatic immune cell accrual and serum alanine aminotransferase levels but similar NAFLD activity score.

Discussion

Collectively, our findings demonstrate that thermoneutral housing has broad but divergent effects on hepatic immune cell inflammation and hepatocellular damage across existing experimental NAFLD models in mice. These insights may serve as a foundation for future mechanistic interrogations focused on immune cell function in shaping NAFLD progression.

Effect of PACAP on Heat Exposure

Heat stroke is a life-threatening illness caused by exposure to high ambient temperatures and relative humidity. The incidence of heat stroke is expected to increase due to climate change. Although pituitary adenylate cyclase-activating polypeptide (PACAP) has been implicated in thermoregulation, the role of PACAP on heat stress remains unclear. PACAP knockout (KO) and wild-type ICR mice were subjected to heat exposure at an ambient temperature of 36 °C and relative humidity of 99% for 30-150 min. After heat exposure, the PACAP KO mice had a greater survival rate and maintained a lower body temperature than the wild-type mice. Moreover, the gene expression and immunoreaction of c-Fos in the ventromedially preoptic area of the hypothalamus, which is known to harbor temperature-sensitive neurons, were significantly lower in PACAP KO mice than those in wild-type mice. In addition, differences were observed in the brown adipose tissue, the primary site of heat production, between PACAP KO and wild-type mice. These results suggest that PACAP KO mice are resistant to heat exposure. The heat production mechanism differs between PACAP KO and wild-type mice.

Difference between brain temperature and core temperature in severe traumatic brain injury: a systematic review

INTRODUCTION

Intensive care management for traumatic brain injury (TBI) patients aims to prevent secondary cerebral damage. Targeted temperature management is one option to prevent cerebral damage, as hypothermia may have protective effects. By conducting a systematic literature review we evaluated: 1) the presence of a temperature difference (gradient) between brain temperature (Tb) and core temperature (Tc) in TBI patients; and 2) clinical factors associated with reported differences.

EVIDENCE ACQUISITION

The PubMed database was systematically searched using Mesh terms and key words, and Web of Sciences was assessed for additional article citations. We included studies that continuously and simultaneously measured Tb and Tc in severe TBI patients. The National Institutes of Health (NIH) quality assessment tool for observational cohort and cross-sectional studies was modified to fit the purpose of our study. Statistical data were extracted for further meta-analyses.

EVIDENCE SYNTHESIS

We included 16 studies, with a total of 480 patients. Clinical heterogeneity consisted of Tb/Tc measurement site, measurement device, physiological changes, local protocols, and medical or surgical interventions. The studies have a high statistical heterogeneity (I2). The pooled mean temperature gradient between Tb and Tc was +0.14 °C (95% confidence interval: 0.03 to 0.24) and ranged from -1.29 to +1.1 °C. Patients who underwent a decompressive (hemi)craniectomy showed lower Tb values compared to Tc found in three studies.

CONCLUSIONS

Studies on Tb and Tc are heterogeneous and show that, on average, Tb and Tc are not clinically significant different in TBI patients (<0.2 °C). Interpretations and interventions of the brain and central temperatures will benefit from standardization of temperature measurements.

Ex Vivo Evaluation of Glutamine Treatment in Sepsis and Trauma in a Human Peripheral Blood Mononuclear Cells Model

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy subjects were incubated with 1 μg/mL LPS at 43 °C (HS). Glutamine 10 mM was added 1 hour before or after induction or not at all. We measured mRNA HSP90α, monocyte (m) and lymphocyte (l) HSP90α proteins, interleukin (IL)-1b, -6, -8, -10, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) supernatant levels. Heat shock increased the HSP90α mRNA and mHSP90α in all groups (10-fold in sepsis, p < 0.001 and p = 0.047, respectively). LPS induced the mHSP90α and lHSP90α in healthy (p < 0.001) and mHSP90α in SIRS (p = 0.004) but not in sepsis. LPS induced the cytokines at 24 and 48 h in all groups, especially in trauma (p < 0.001); HS only induced the IL-8 in healthy (p = 0.003) and septic subjects (p = 0.05). Glutamine at 10 mM before or after stimulation did not alter any induction effect of LPS or HS on HSP90α mRNA and mHSP90α protein in sepsis. In SIRS, glutamine before LPS decreased the mHSP90α but increased it when given after HS (p = 0.018). Before or after LPS (p = 0.049) and before HS (p = 0.018), glutamine decreased the lHSP90α expression in sepsis but increased it in SIRS when given after HS (p = 0.003). Regarding cytokines, glutamine enhanced the LPS-induced MCP-1 at 48 h in healthy (p = 0.011), SIRS (p < 0.001), and sepsis (p = 0.006). In conclusion, glutamine at 10 mM, before or after LPS and HS, modulates mHSP90α and lHSP90α in sepsis and SIRS differently and unpredictably. Although it does not alter the stimulation effect on interleukins, glutamine enhances the LPS induction effect on supernatant MCP-1 in all groups. Future research should seek to elucidate better the impact of glutamine and temperature modulation on HSP90α and MCP-1 pathways in sepsis and trauma.

Antipyretic Potential of 80% Methanol Extract and Solvent Fractions of Bersama abyssinica Fresen. (Melianthaceae) Leaves Against Yeast-Induced Pyrexia in Mice

Introduction

Since fever is a complicated physiological reaction to an infection or aseptic stimulus, finding safer solutions that are more potent and derived from plants is essential to resolving this issue. Bersama abyssinica (Melianthaceae) is traditionally used to treat fever, though this has yet to be proven scientifically.

Objective

The present study aimed to assess the antipyretic potential of leaf extract and solvent fractions of B. abyssinica.

Methods

The antipyretic activities of crude extract and solvent fractions of B. abyssinica leaves were evaluated using a yeast-induced pyrexia model at three different dose ranges (100mg/kg, 200mg/kg, and 400mg/kg) methanol extract as well as chloroform, ethyl acetate, and aqueous fractions to mice showing an increase in temperature of ≥0.5 °C. The rectal temperature of each mouse was recorded using a digital thermometer. To analyze the data, SPSS version 20 and one-way ANOVA followed by Tukey's HSD post hoc test to compare results between groups were utilized.

Results

The crude extract demonstrated significant antipyretic potential (P<0.05 by 100 mg/kg and 200 mg/kg as well as P<0.01 by 400 mg/kg), with a maximum of 95.06% reduction in rectal temperature at 400 mg/kg, comparable to 98.37% at 2.5 hours by the standard drug. Similarly, all doses of the aqueous fraction, as well as 200 mg/kg and 400 mg/kg doses of the ethyl acetate fractions, resulted in a significant (P<0.05) reduction in rectal temperature when compared to the corresponding value of the negative control group.

Conclusion

Extracts of B. abyssinica leaves were found to have a significant antipyretic effect. Thus, the use of the plant for pyrexia in traditional settings has scientific ground.

Headache attributed to SARS-CoV-2 infection, vaccination and the impact on primary headache disorders of the COVID-19 pandemic: A comprehensive review

OBJECTIVE

The objective is to summarize the knowledge on the epidemiology, pathophysiology and management of secondary headache attributed to SARS-CoV-2 infection and vaccination; as well as to delineate their impact on primary headache disorders.

METHODS

This is a narrative review of the literature regarding primary and secondary headache disorders in the setting of COVID-19 pandemic. We conducted a literature search in 2022 on PubMed, with the keywords "COVID 19" or "vaccine" and "headache" to assess the appropriateness of all published articles for their inclusion in the review.

RESULTS

Headache is a common and sometimes difficult-to-treat symptom of both the acute and post-acute phase of SARS-CoV-2 infection. Different pathophysiological mechanisms may be involved, with the trigeminovascular system as a plausible target. Specific evidence-based effective therapeutic options are lacking at present. Headache attributed to SARS-CoV-2 vaccinations is also common, its pathophysiology being unclear. People with primary headache disorders experience headache in the acute phase of COVID-19 and after vaccination more commonly than the general population. Pandemic measures, forcing lifestyle changes, seemed to have had a positive impact on migraine, and changes in headache care (telemedicine) have been effectively introduced.

CONCLUSIONS

The ongoing COVID-19 pandemic is a global challenge, having an impact on the development of secondary headaches, both in people with or without primary headaches. This has created opportunities to better understand and treat headache and to potentiate strategies to manage patients and ensure care.

Elevated body temperature and leukocyte count are associated with elevated creatine kinase after seizures

Objective

To evaluate the independent risk factors for elevated creatine kinase (hyperCKemia) after seizures.

Methods

Data included in this retrospective study were obtained from two hospitals from July 1, 2017, to March 31, 2022. Clinical and laboratory data were acquired from the emergency department or within 24 h after patient admission. Variables that exhibited statistical differences (P < 0.05) were selected for further analysis. Associations between body temperature (BT), leukocyte count (LEU), percentage of neutrophils (NEU), and C-reactive protein (CRP) and creatine kinase (CK) levels were assessed using binary logistic regression analysis.

Results

One hundred twenty-three patients who exhibited seizures were included in the study, and 39 (31.7%) patients exhibited hyperCKemia based on a CK level that was >1.5 times the upper limit of the normal range for CK. No statistical differences were observed among the patient characteristics, seizure-related parameters, or electrolyte levels. However, BT, LEU, NEU, and CRP were elevated in patients with hyperCKemia compared to patients with normal CK levels. Specifically, a BT ≥ 37.5 °C (fever) and LEU >9.5×10⁹/L (elevated LEU) exhibited positive correlations with hyperCKemia, and presented an adjusted OR of 8.87 (95% CI: 2.11-37.24, P = 0.003) and 3.01 (95% CI: 1.12-8.05, P = 0.029), respectively.

Conclusion

In this study, hyperCKemia occurred in 31.7% of patients after seizures. Fever and elevated LEU were independent risk factors for seizure-related hyperCKemia. Earlier recognition of risks for seizure-related hyperCKemia would be beneficial in taking prophylactic measures.

Prospecting for candidate molecules from Conus virgo toxins to develop new biopharmaceuticals

Background

A combination of pharmacological and biomedical assays was applied in this study to examine the bioactivity of Conus virgo crude venom in order to determine the potential pharmacological benefit of this venom, and its in vivo mechanism of action.

Methods

Two doses (1/5 and 1/10 of LC₅₀, 9.14 and 4.57 mg/kg) of the venom were used in pharmacological assays (central and peripheral analgesic, anti-inflammatory and antipyretic), while 1/2 of LC₅₀ (22.85 mg/kg) was used in cytotoxic assays on experimental animals at different time intervals, and then compared with control and reference drug groups.

Results

The tail immersion time was significantly increased in venom-treated mice compared with the control group. Also, a significant reduction in writhing movement was recorded after injection of both venom doses compared with the control group. In addition, only the high venom concentration has a mild anti-inflammatory effect at the late inflammation stage. The induced pyrexia was also decreased significantly after treatment with both venom doses. On the other hand, significant increases were observed in lipid peroxidation (after 4 hours) and reduced glutathione contents and glutathione peroxidase activity, while contents of lipid peroxidation and nitric oxide (after 24 hours) and catalase activity were depleted significantly after venom administration.

Conclusion

These results indicated that the crude venom of Conus virgo probably contain bioactive components that have pharmacological activities with low cytotoxic effects. Therefore, it may comprise a potential lead compound for the development of drugs that would control pain and pyrexia.

Cerebral Oxygen Delivery and Consumption in Brain-Injured Patients

Organism survival depends on oxygen delivery and utilization to maintain the balance of energy and toxic oxidants production. This regulation is crucial to the brain, especially after acute injuries. Secondary insults after brain damage may include impaired cerebral metabolism, ischemia, intracranial hypertension and oxygen concentration disturbances such as hypoxia or hyperoxia. Recent data highlight the important role of clinical protocols in improving oxygen delivery and resulting in lower mortality in brain-injured patients. Clinical protocols guide the rules for oxygen supplementation based on physiological processes such as elevation of oxygen supply (by mean arterial pressure (MAP) and intracranial pressure (ICP) modulation, cerebral vasoreactivity, oxygen capacity) and reduction of oxygen demand (by pharmacological sedation and coma or hypothermia). The aim of this review is to discuss oxygen metabolism in the brain under different conditions.

Clinical Potential of Himalayan Herb Bergenia ligulata: An Evidence-Based Study

Herbal products have been used in traditional systems of medicine and by ethnic healers for ages to treat various diseases. Currently, it is estimated that about 80% of people worldwide use herbal traditional medicines against various ailments, partly due to easy accessibility and low cost, and the lower side effects they pose. Bergenia ligulata, a herb ranging from the Himalayas to the foothills, including the north-eastern states of India, has traditionally been used as a remedy against various diseases, most prominently kidney stones. The medicinal properties of B. ligulata have been attributed to bergenin, its most potent bioactive component. Apart from bergenin, the other compounds available in B. ligulata are arbutin, gallic acid, protocatechuic acid, chlorogenic acid, syringic acid, catechin, ferulic acid, afzelechin, paashaanolactone, caryophyllene, 1,8-cineole, β-eudesmol, stigmasterol, β-sitosterol, parasorbic acid, 3-methyl-2-buten-1-ol, phytol, terpinen-4-ol, tannic acid, isovalaric acid, avicularin, quercetin, reynoutrin, and sitoinoside I. This review summarizes various medicinal properties of the herb, along with providing deep insight into its bioactive molecules and their potential roles in the amelioration of human ailments. Additionally, the possible mechanism(s) of action of the herb's anti-urolithiatic, antioxidative, antipyretic, anti-diabetic, anti-inflammatory and hepatoprotective properties are discussed. This comprehensive documentation will help researchers to better understand the medicinal uses of the herb. Further studies on B. ligulata can lead to the discovery of new drug(s) and therapeutics for various ailments.

The utility of therapeutic hypothermia on cerebral autoregulation

Cerebral autoregulation (CA) dysfunction is a strong predictor of clinical outcome in patients with acute brain injury (ABI). CA dysfunction is a potential pathologic defect that may lead to secondary injury and worse functional outcomes. Early therapeutic hypothermia (TH) in patients with ABI is controversial. Many factors, including patient selection, timing, treatment depth, duration, and rewarming strategy, impact its clinical efficacy. Therefore, optimizing the benefit of TH is an important issue. This paper reviews the state of current research on the impact of TH on CA function, which may provide the basis and direction for CA-oriented target temperature management.

The symptomatology of fever: A step towards qualitative definition of fever

Background

The old definitions of fever are based on cross-sectional surveys of the population without analyzing the associated symptomatology as fever is a sign, not symptom. Therefore, a longitudinal follow-up study is the need of hour to analyze associated symptoms with fever.

Methods

In a longitudinal study over one year, 196 participants recorded three temperature readings daily, one after waking up, one between 12 and 3 PM, one before sleeping, and filled the symptomatology questionnaire in a thermometry diary.

Results

Per protocol analysis was done for febrile participants (n = 144). Fatigue (50.3%), warmth (47.3%), headache/head heaviness (47.0%), feeling malaise/general weakness (46.7%), loss of appetite (46.5%), muscle cramps/muscle aches (45.6%), chills/shivering (44.6%), increased sweating (43.0%), nausea (42.5%), irritability (38.9%), increased breathing rate (37.1%), and restlessness/anxiety/palpitations (36.5%) were the symptoms maximally seen during the febrile phase. A higher number of associated symptoms are associated with higher temperature readings. Dehydration suggested the numerically highest temperature values (100.86 ± 1.70°F) but seen in few febrile patients.

Conclusions

Incorporation of symptom analysis in febrile patients is the need of the hour. Fatigue and warmth are found to be the most prevalent symptoms during febrile phase. Associated symptoms can help in predicting the intensity of fever also.

Sequential organ failure assessment score as a predictor of the outcomes of patients hospitalized for classical or exertional heatstroke

Heatstroke is a life-threatening event that affects people worldwide. Currently, there are no established tools to predict the outcomes of heatstroke. Although the Sequential Organ Failure Assessment (SOFA) score is a promising tool for judging the severity of critically ill patients. Therefore, in this study, we investigated whether the SOFA score could predict the outcome of patients hospitalized with severe heatstroke, including the classical and exertional types, by using data from a Japanese nationwide multicenter observational registry. We performed retrospective subanalyses of the Japanese Association for Acute Medicine heatstroke registry, 2019. Adults with a SOFA score ≥ 1 hospitalized for heatstroke were analyzed. We analyzed data for 225 patients. Univariate and multivariable analyses showed a significant difference in the SOFA score between non-survivors and survivors in classical and exertional heatstroke cases. The area under the receiver operating characteristic curve were 0.863 (classical) and 0.979 (exertional). The sensitivity and specificity of SOFA scores were 50.0% and 97.5% (classical), 66.7% and 97.5% (exertional), respectively, at a cutoff of 12.5, and 35.0% and 98.8% (classical), 33.3% and 100.0% (exertional), respectively, at a cutoff of 13.5. This study revealed that the SOFA score may predict mortality in patients with heatstroke and might be useful for assessing prognosis.