The innate immune system can be boosted in response to subsequent triggers by pre-exposure to microbes or microbial products, known as “trained immunity”. Compared to classical immune memory, innate trained immunity has several different features. Firstly, the molecules involved in trained immunity differ from those involved in classical immune memory. Innate trained immunity mainly involves innate immune cells (e.g., myeloid immune cells, natural killer cells, innate lymphoid cells) and their effector molecules (e.g., pattern recognition receptor (PRR), various cytokines), as well as some kinds of non-immune cells (e.g., microglial cells). Secondly, the increased responsiveness to secondary stimuli during innate trained immunity is not specific to a particular pathogen, but influences epigenetic reprogramming in the cell through signaling pathways, leading to the sustained changes in genes transcriptional process, which ultimately affects cellular physiology without permanent genetic changes (e.g., mutations or recombination). Finally, innate trained immunity relies on an altered functional state of innate immune cells that could persist for weeks to months after initial stimulus removal. An appropriate inducer could induce trained immunity in innate lymphocytes, such as exogenous stimulants (including vaccines) and endogenous stimulants, which was firstly discovered in bone marrow derived immune cells. However, mature bone marrow derived immune cells are short-lived cells, that may not be able to transmit memory phenotypes to their offspring and provide long-term protection. Therefore, trained immunity is more likely to be relied on long-lived cells, such as epithelial stem cells, mesenchymal stromal cells and non-immune cells such as fibroblasts. Epigenetic reprogramming is one of the key molecular mechanisms that induces trained immunity, including DNA modifications, non-coding RNAs, histone modifications and chromatin remodeling. In addition to epigenetic reprogramming, different cellular metabolic pathways are involved in the regulation of innate trained immunity, including aerobic glycolysis, glutamine catabolism, cholesterol metabolism and fatty acid synthesis, through a series of intracellular cascade responses triggered by the recognition of PRR specific ligands. In the view of evolutionary, trained immunity is beneficial in enhancing protection against secondary infections with an induction in the evolutionary protective process against infections. Therefore, innate trained immunity plays an important role in therapy against diseases such as tumors and infections, which has signature therapeutic effects in these diseases. In organ transplantation, trained immunity has been associated with acute rejection, which prolongs the survival of allografts. However, trained immunity is not always protective but pathological in some cases, and dysregulated trained immunity contributes to the development of inflammatory and autoimmune diseases. Trained immunity provides a novel form of immune memory, but when inappropriately activated, may lead to an attack on tissues, causing autoinflammation. In autoimmune diseases such as rheumatoid arthritis and atherosclerosis, trained immunity may lead to enhance inflammation and tissue lesion in diseased regions. In Alzheimer’s disease and Parkinson’s disease, trained immunity may lead to over-activation of microglial cells, triggering neuroinflammation even nerve injury. This paper summarizes the basis and mechanisms of innate trained immunity, including the different cell types involved, the impacts on diseases and the effects as a therapeutic strategy to provide novel ideas for different diseases.

This study employed the "disease-medicine-dose" pattern to mine the medication rules of traditional Chinese medicine(TCM) prescriptions containing Astragali Radix in ancient Chinese medical books, aiming to provide a scientific basis for the clinical application of Astragali Radix and the development of new medicines. The TCM prescriptions containing Astragali Radix were retrieved from databases such as Chinese Medical Dictionary and imported into Excel 2020 to construct the prescription library. Statical analysis were performed for the prescriptions regarding the indications, syndromes, medicine use frequency, herb effects, nature and taste, meridian tropism, dosage forms, and dose. SPSS statistics 26.0 and IBM SPSS Modeler 18.0 were used for association rules analysis and cluster analysis. A total of 2 297 prescriptions containing Astragali Radix were collected, involving 233 indications, among which sore and ulcer, consumptive disease, sweating disorder, and apoplexy had high frequency(>25), and their syndromes were mainly Qi and blood deficiency, Qi and blood deficiency, Yin and Yang deficiency, and Qi deficiency and collateral obstruction, respectively. In the prescriptions, 98 medicines were used with the frequency >25 and they mainly included Qi-tonifying medicines and blood-tonifying medicines. Glycyrrhizae Radix et Rhizoma, Angelicae Sinensis Radix, Ginseng Radix et Rhizoma, Atractylodis Macrocephalae Rhizoma, and Citri Reticulatae Pericarpium were frequently used. The medicines with high frequency mainly have warm or cold nature, and sweet, pungent, or bitter taste, with tropism to spleen, lung, heart, liver, and kidney meridians. In the treatment of sore and ulcer, Astragali Radix was mainly used with the dose of 3.73 g and combined with Glycyrrhizae Radix et Rhizoma to promote granulation and heal up sores. In the treatment of consumptive disease, Astragali Radix was mainly used with the dose of 37.30 g and combined with Ginseng Radix et Rhizoma to tonify deficiency and replenish Qi. In the treatment of sweating disorder, Astragali Radix was mainly used with the dose of 3.73 g and combined with Glycyrrhizae Radix et Rhizoma to consolidate exterior and stop sweating. In the treatment of apoplexy, Astragali Radix was mainly used with the dose of 7.46 g and combined with Glycyrrhizae Radix et Rhizoma to dispell wind and stop convulsions. Astragali Radix can be used in the treatment of multiple system diseases, with the effects of tonifying Qi and ascending Yang, consolidating exterior and stopping sweating, and expressing toxin and promoting granulation. According to the manifestations of different diseases, when combined with other medicines, Astragali Radix was endowed with the effects of promoting granulation and healing up sores, tonifying deficiency and Qi, consolidating exterior and stopping sweating, and dispelling wind and replenishing Qi. The findings provide a theoretical reference and a scientific basis for the clinical application of Astragali Radix and the development of new medicines.
Drugs, Chinese Herbal/history* ; Humans ; Medicine, Chinese Traditional/history* ; History, Ancient ; Astragalus Plant/chemistry* ; China ; Astragalus propinquus

This study primarily investigates the effect of Liuwei Dihuang Pills on the activation and proliferation of female germline stem cells(FGSCs) in the ovaries and cortex of mice with premature ovarian failure(POF), and how it improves ovarian function. ICR mice were randomly divided into the control group, model group, Liuwei Dihuang Pills group, Liuwei Dihuang Pills double-dose group, and estradiol valerate group. A mouse model of POF was established by intraperitoneal injection of cyclophosphamide. After successful modeling, the mice were treated with Liuwei Dihuang Pills or estradiol valerate for 28 days. Vaginal smears were prepared to observe the estrous cycle and body weight. After the last administration, mice were sacrificed and sampled. Serum levels of estradiol(E_2), follicle-stimulating hormone(FSH), luteinizing hormone(LH), and anti-Müllerian hormone(AMH) were measured by enzyme-linked immunosorbent assay(ELISA). Hematoxylin-eosin(HE) staining was used to observe ovarian morphology and to count follicles at all stages to evaluate ovarian function. Immunohistochemistry was used to detect the expression of mouse vasa homolog(MVH), a marker of ovarian FGSCs. Immunofluorescence staining, using co-labeling of MVH and proliferating cell nuclear antigen(PCNA), was used to detect the expression and localization of specific markers of FGSCs. Western blot was employed to assess the protein expression of MVH, octamer-binding transcription factor 4(Oct4), and PCNA in the ovaries. The results showed that compared with the control group, the model group exhibited disordered estrous cycles, decreased ovarian index, increased atretic follicles, and a reduced number of follicles at all stages. FSH and LH levels were significantly elevated, while AMH and E_2 levels were significantly reduced, indicating the success of the model. After treatment with Liuwei Dihuang Pills or estradiol valerate, hormone levels improved, the number of atretic follicles decreased, and the number of follicles at all stages increased. MVH marker protein and PCNA proliferative protein expression in ovarian tissue also increased. These results suggest that Liuwei Dihuang Pills regulate estrous cycles and hormone disorders in POF mice, promote the proliferation of FGSCs, improve follicular development in POF mice, and enhance ovarian function.
Animals ; Female ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Cell Proliferation/drug effects* ; Mice, Inbred ICR ; Ovary/cytology* ; Primary Ovarian Insufficiency/genetics* ; Follicle Stimulating Hormone/metabolism* ; Humans ; Anti-Mullerian Hormone/blood* ; Antineoplastic Agents/adverse effects* ; Luteinizing Hormone/metabolism* ; Cyclophosphamide/adverse effects*

This study aimed to investigate the correlation between changes in intestinal toxicity and compositional alterations of Euphorbiae Ebracteolatae Radix(commonly known as Langdu) before and after milk processing, and to explore the detoxification mechanism of milk processing. Mice were intragastrically administered the 95% ethanol extract of raw Euphorbiae Ebracteolatae Radix, milk-decocted(milk-processed), and water-decocted(water-processed) Euphorbiae Ebracteolatae Radix. Fecal morphology, fecal water content, and the release levels of inflammatory cytokines tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) in different intestinal segments were used as indicators to evaluate the effects of different processing methods on the cathartic effect and intestinal inflammatory toxicity of Euphorbiae Ebracteolatae Radix. LC-MS/MS was employed to analyze the small-molecule components in the raw product, the 95% ethanol extract of the milk-processed product, and the milky waste(precipitate) formed during milk processing, to assess the impact of milk processing on the chemical composition of Euphorbiae Ebracteolatae Radix. The results showed that compared with the blank group, both the raw and water-processed Euphorbiae Ebracteolatae Radix significantly increased the fecal morphology score, fecal water content, and the release levels of TNF-α and IL-1β in various intestinal segments(P<0.05). Compared with the raw group, all indicators in the milk-processed group significantly decreased(P<0.05), while no significant differences were observed in the water-processed group, indicating that milk, as an adjuvant in processing, plays a key role in reducing the intestinal toxicity of Euphorbiae Ebracteolatae Radix. Mass spectrometry results revealed that 29 components were identified in the raw product, including 28 terpenoids and 1 acetophenone. The content of these components decreased to varying extents after milk processing. A total of 28 components derived from Euphorbiae Ebracteolatae Radix were identified in the milky precipitate, of which 27 were terpenoids, suggesting that milk processing promotes the transfer of toxic components from Euphorbiae Ebracteolatae Radix into milk. To further investigate the effect of milk adjuvant processing on the toxic terpenoid components of Euphorbiae Ebracteolatae Radix, transmission electron microscopy(TEM) was used to observe the morphology of self-assembled casein micelles(the main protein in milk) in the milky precipitate. The micelles formed in casein-terpenoid solutions were characterized using particle size analysis, fluorescence spectroscopy, ultraviolet spectroscopy, and Fourier-transform infrared(FTIR) spectroscopy. TEM observations confirmed the presence of casein micelles in the milky precipitate. Characterization results showed that with increasing concentrations of toxic terpenoids, the average particle size of casein micelles increased, fluorescence intensity of the solution decreased, the maximum absorption wavelength in the UV spectrum shifted, and significant changes occurred in the infrared spectrum, indicating that interactions occurred between casein micelles and toxic terpenoid components. These findings indicate that the cathartic effect of Euphorbiae Ebracteolatae Radix becomes milder and its intestinal inflammatory toxicity is reduced after milk processing. The detoxification mechanism is that terpenoid components in Euphorbiae Ebracteolatae Radix reassemble with casein in milk to form micelles, promoting the transfer of some terpenoids into the milky precipitate.
Animals ; Mice ; Milk/chemistry* ; Drugs, Chinese Herbal/chemistry* ; Male ; Tumor Necrosis Factor-alpha/immunology* ; Intestines/drug effects* ; Interleukin-1beta/immunology* ; Tandem Mass Spectrometry ; Female

Ultra performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry/mass spectrometry(UPLC-Q-TOF-MS/MS), network pharmacology, and animal experiments were integrated o explore the blood glucose-lowering effects and mechanisms of Poria aqueous extract. Firstly, the active components of Poria aqueous extract were identified by UPLC-Q-TOF-MS/MS. Subsequently, network pharmacology was employed to predict the blood glucose-lowering components and mechanisms of Poria aqueous extract. Finally, a rat model of diabetes mellitus, 16S rDNA sequencing, and Western blot were employed to investigate the blood glucose-lowering effect and mechanism of Poria aqueous extract. A total of 39 triterpenoids were identified in the Poria aqueous extract, among them, 25-hydroxypachymic acid, 25α-hydroxytumulosic acid, 16α-hydroxytrametenolic acid, polyporenic acid C, and tumulosic acid may be the main active ingredients for treating diabetes. The Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis revealed that Poria might exert its therapeutic effects through multiple pathways such as NOD-like receptor signaling pathway, nuclear factor-kappa B(NF-κB) signaling pathway, and tumor necrosis factor(TNF) signaling pathway. The results of animal experiments demonstrated that Poria aqueous extract significantly reduced the levels of blood glucose and lipids and regulated the intestinal flora in diabetic rats. The main affected taxa included g＿Escherichia-Shigella, g＿Corynebacterium, g＿Prevotella＿9, g＿Prevotellaceae＿UCG-001, and g＿Bacteroidota＿unclassified. In addition, Poria aqueous extract lowered the levels of D-lactic acid and lipopolysaccharide, alleviated colonic mucosal damage, significantly down-regulated the protein levels of NOD-like receptor pyrin domain-containing protein 3(NLRP3), NF-κB, and TNF-α, and significantly up-regulated the protein levels of zonula occludens 1 and occludin in diabetic rates. Poria aqueous extract may play a role in treating diabetes mellitus by repairing the intestinal flora disturbance, protecting the intestinal barrier function, and inhibiting the NF-κB/NLRP3 signaling pathway. The results provide a scientific basis for clinical application and expansion of indications of Poria.
Animals ; Rats ; Network Pharmacology ; Tandem Mass Spectrometry ; Male ; Drugs, Chinese Herbal/pharmacology* ; Chromatography, High Pressure Liquid ; Blood Glucose/drug effects* ; Rats, Sprague-Dawley ; Hypoglycemic Agents/administration & dosage* ; Poria/chemistry* ; Diabetes Mellitus, Experimental/metabolism* ; NF-kappa B/genetics* ; Gastrointestinal Microbiome/drug effects* ; Humans

This article aims to explore the effect and mechanism of Liujunzi Pills on the intestinal microbiota of rats with spleen Qi deficiency syndrome. The raw Rhei Radix et Rhizoma water extract(1 g·mL~(-1)) was used to prepare spleen Qi deficiency rat models. A total of 44 SD male rats were randomly divided into a control group, a model group, Liujunzi Pills groups at high(3.24 g·kg~(-1)), medium(1.62 g·kg~(-1)), low(0.81 g·kg~(-1)) doses, and Shenling Baizhu San(2.50 g·kg~(-1)) group. The drug effect was evaluated by observing the following aspects: spleen index, fecal water content, body weight, and intestinal propulsion index. Gut microbiota analysis and 16S rRNA gene sequencing were conducted on feces. Enzyme-linked immunosorbent assay(ELISA) and UV spectrophotometry were used to detect interleukin-1β(IL-1β) and adenosine triphosphate(ATP) levels in small intestine tissues. Hematoxylin-eosin staining and transmission electron microscopy were employed to observe changes in intestinal pathology and microstructure. The results show that, compared with the control group, fecal moisture content is significantly increased while spleen index, body weight, and intestinal propulsion index are significantly reduced in rats of the model group, indicating the successful establishment of the model. The above symptoms can be improved by both Shenling Baizhu San and Liujunzi Pills. Compared with the control group, in the model group, the gut microbiota abundance is changed with an unbalanced development: the abundance of beneficial bacteria within the Bacteroidetes phylum is reduced, accompanied by a significantly decreased Shannon index, and reduced signal levels of nicotinamide adenine dinucleotide phosphate(NADPH)-related enzymes relevant to mitochondria. However, Liujunzi Pills and Shenling Baizhu San can significantly improve the Bacteroidetes phylum abundance in gut microbiota, microbial diversity, and NADPH activity in the model group. Additionally, compared with the control group, the ATP level is decreased and the IL-1β level is increased in small intestinal tissues of the model group, with shorter small intestinal epithelial villi and decreased mitochondrial number. The above symptoms can be improved by Liujunzi Pills and Shenling Baizhu San. In conclusion, Liujunzi Pills can treat spleen Qi deficiency syndrome by enhancing mitochondrial function to regulate gut microbiota balance and diversity.
Animals ; Gastrointestinal Microbiome/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Male ; Rats, Sprague-Dawley ; Rats ; Qi ; Spleen/metabolism* ; Splenic Diseases/metabolism* ; Humans ; Interleukin-1beta/genetics* ; Bacteria/drug effects* ; Feces/microbiology* ; Adenosine Triphosphate/metabolism*

To investigate the impact of preoperative serum follicle-stimulating hormone (FSH) levels on the probability of testicular sperm retrieval, we conducted a study of nonobstructive azoospermic (NOA) men with different testicular volumes (TVs) who underwent microdissection testicular sperm extraction (micro-TESE). A total of 177 NOA patients undergoing micro-TESE for the first time from April 2019 to November 2022 in Shenzhen Zhongshan Obstetrics and Gynecology Hospital (formerly Shenzhen Zhongshan Urology Hospital, Shenzhen, China) were retrospectively reviewed. The subjects were divided into four groups based on average TV quartiles. Serum hormone levels in each TV group were compared between positive and negative sperm retrieval subgroups. Overall sperm retrieval rate was 57.6%. FSH levels (median [interquartile range]) were higher in the positive sperm retrieval subgroup compared with the negative outcome subgroup when average TV was <5 ml (first quartile [Q1: TV <3 ml]: 43.32 [17.92] IU l -1 vs 32.95 [18.56] IU l -1 , P = 0.048; second quartile [Q2: 3 ml ≤ TV <5 ml]: 31.31 [15.37] IU l -1 vs 25.59 [18.40] IU l -1 , P = 0.042). Elevated serum FSH levels were associated with successful micro-TESE sperm retrieval in NOA men whose average TVs were <5 ml (adjusted odds ratio [OR]: 1.06 per unit increase; 95% confidence interval [CI]: 1.01-1.11; P = 0.011). In men with TVs ≥5 ml, larger TVs were associated with lower odds of sperm retrieval (adjusted OR: 0.84 per 1 ml increase; 95% CI: 0.71-0.98; P = 0.029). In conclusion, elevated serum FSH levels were associated with positive sperm retrieval in micro-TESE in NOA men with TVs <5 ml. In men with TV ≥5 ml, increases in average TVs were associated with lower odds of sperm retrieval.
Humans ; Male ; Azoospermia/surgery* ; Sperm Retrieval/statistics & numerical data* ; Adult ; Follicle Stimulating Hormone/blood* ; Retrospective Studies ; Testis/pathology* ; Microdissection ; Organ Size

OBJECTIVES: To summarize the clinical characteristics, diagnosis, and treatment outcomes of neonatal venous thrombosis. METHODS: A retrospective analysis was conducted on the clinical data of 11 neonates with venous thrombosis admitted to the Department of Neonatology of Anhui Children's Hospital from January 2019 to September 2024. The clinical characteristics, diagnostic approaches, treatments, and outcomes were analyzed. RESULTS: Among the 11 neonates diagnosed with venous thrombosis, 5 were male, and 6 were preterm infants, with a median gestational age of 35⁺⁶ weeks, birth weight of (2 322±1 069) g, and admission temperature of (36.6±0.4)°C. The median age at symptom onset was 6 days. Of the 11 cases, 8 limb venous thromboses and 1 portal vein thrombosis were confirmed by vascular ultrasound, and 2 cases of intracranial venous sinus thrombosis were confirmed by magnetic resonance imaging. Ten cases received low molecular weight heparin for anticoagulation, with a treatment duration of (24±15) days; 2 cases were treated with urokinase thrombolysis, and 4 cases received fresh frozen plasma transfusion. Thrombosis resolved in 7 cases before discharge. Partial resolution occurred in 2 cases before discharge (1 continued outpatient treatment until resolution and 1 resolved during follow-up). One case was transferred to another hospital after 1 day of treatment and was discharged after thrombosis reduction. No adverse reactions such as bleeding were observed. One neonate with cerebral infarction at admission did not receive heparin anticoagulation and was followed up as an outpatient. CONCLUSIONS Vascular ultrasound is the most commonly used diagnostic method for neonatal venous thrombosis. Heparin anticoagulation is the recommended treatment. The overall prognosis of neonatal venous thrombosis is favorable.
Humans ; Male ; Venous Thrombosis/drug therapy* ; Infant, Newborn ; Female ; Retrospective Studies

OBJECTIVES: To investigate the chain mediating role of family care and emotional management in the relationship between social support and anxiety among rural primary school students. METHODS: A questionnaire survey was conducted among students in grades 4 to 6 from four counties in Hunan Province. Data were collected using the Social Support Rating Scale, Family Care Index Scale, Emotional Intelligence Scale, and Generalized Anxiety Disorder -7. Logistic regression analysis was used to explore the influencing factors of anxiety symptoms. Mediation analysis was conducted to assess the chain mediating effects of family care and emotional management between social support and anxiety. RESULTS: A total of 4 141 questionnaires were distributed, with 3 874 valid responses (effective response rate: 93.55%). The prevalence rate of anxiety symptoms among these students was 9.32% (95%CI: 8.40%-10.23%). Significant differences were observed in the prevalence rates of anxiety symptoms among groups with different levels of social support, family functioning, and emotional management ability (P<0.05). The total indirect effect of social support on anxiety symptoms via family care and emotional management was significant (β=-0.137, 95%CI: -0.167 to -0.109), and the direct effect of social support on anxiety symptoms remained significant (P<0.05). Family care and emotional management served as significant chain mediators in the relationship between social support and anxiety symptoms (β=-0.025,95%CI:-0.032 to -0.018), accounting for 14.5% of the total effect. CONCLUSIONS Social support can directly affect anxiety symptoms among rural primary school students and can also indirectly influence anxiety symptoms through the chain mediating effects of family care and emotional management. These findings provide scientific evidence for the prevention of anxiety in primary school students from multiple perspectives.
Humans ; Female ; Male ; Social Support ; Anxiety/etiology* ; Child ; Students/psychology* ; Emotions ; Logistic Models

OBJECTIVE: To investigate the risk factors, clinical characteristics, and bacterial resistance of bloodstream infections caused by Streptococcus mitis in children with hematological disease, so as to provide a reference for infection control. METHODS: The clinical information and laboratory findings of pediatric patients complicated with blood cultures positive for Streptococcus mitis from January 2018 to December 2020 in the Institute of Hematology & Blood Diseases Hospital were searched and collected. The clinical characteristics, susceptibility factors, and antibiotic resistance of the children were retrospectively analyzed. RESULTS: Data analysis from 2018 to 2020 showed that the proportion of Streptococcus mitis isolated from bloodstream infections in children (≤14 years old) with hematological diseases was the highest (19.91%) and significantly higher than other bacteria, accounting for 38.64% of Gram-positive cocci, and presented as an increasing trend year by year. A total of 427 children tested positive blood cultures, including 85 children with bloodstream infections caused by Streptococcus mitis who tested after fever. Most children experienced a recurrent high fever in the early and middle stages (≤6 d) of neutropenia and persistent fever for more than 3 days. After adjusting the antibiotics according to the preliminary drug susceptibility results, the body temperature of most children (63.5%) returned to normal within 4 days. The 85 children were mainly diagnosed with acute myeloid leukemia (AML), accounting for 84.7%. The proportion of children in the neutropenia stage was 97.7%. The incidence of oral mucosal damage, lung infection, and gastrointestinal injury symptoms was 40%, 31.8%, and 27.1%, respectively. The ratio of elevated C-reactive protein (CRP) and procalcitonin was 65.9% and 9.4%, respectively. All isolated strains of Streptococcus mitis were not resistant to vancomycin and linezolid, and the resistance rate to penicillin, cefotaxime, levofloxacin, and quinupristin-dalfopristin was 10.6%, 8.2%, 9.4%, and 14.1%, respectively. None of children died due to bloodstream infection caused by Streptococcus mitis. CONCLUSION The infection rate of Streptococcus mitis is increasing year by year in children with hematological diseases, especially in children with AML. Among them, neutropenia and oral mucosal damage after chemotherapy are high-risk infection factors. The common clinical symptoms include persistent high fever, oral mucosal damage, and elevated CRP. Penicillin and cephalosporins have good sensitivity. Linezolid, as a highly sensitive antibiotic, can effectively control infection and shorten the course of disease.
Humans ; Child ; Streptococcal Infections/microbiology* ; Retrospective Studies ; Hematologic Diseases/complications* ; Streptococcus mitis ; Drug Resistance, Bacterial ; Risk Factors ; Microbial Sensitivity Tests ; Anti-Bacterial Agents ; Female ; Male ; Bacteremia/microbiology* ; Child, Preschool ; Adolescent