Character-Audience Racial Matching, Prescription Opioid Misuse Experience, and the Effectiveness of Anti-Prescription Opioid Messages: The Mediating Roles of Identification and Perceived Severity.

An online experiment was conducted among a convenience sample of non-Hispanic young Black and White Americans to test the impact of character-audience racial matching on intentions to avoid (mis)using prescription opioids while considering the mediating roles of identification and perceived severity and the moderating role of prescription opioid misuse experience. It found that the racial matching had a positive overall impact on the behavioral intentions. The impact was partly explained by three pathways: 1) identification, 2) perceived severity, and 3) the sequential pathway of identification and perceived severity. It also found that prescription opioid misuse experience moderated the impact of the racial matching on identification. As a result, the racial matching was found to influence the behavioral intentions of participants with different prescription opioid misuse experience via somewhat different routes. These findings have a number of theoretical and practical implications.

An adapted white-coat and warm-heart intervention on nurses' knowledge, general stigmatizing attitudes, and work avoidance behaviors towards HIV: a quasi-experimental study.

OBJECTIVES: To determine the effect of an adapted white-coat and warm-heart intervention (AWWI) among nurses. BACKGROUND: HIV discrimination among medical staff hinders progress in HIV prevention. METHODS: A total of 779 nurses were randomized into intervention and control groups. The intervention group was provided with AWWI training. The control group did not receive AWWI training. HIV-related knowledge, attitudes, and behaviors of participants were assessed. RESULTS: Participants in the intervention group had better HIV-related knowledge and less stigmatizing attitudes and work avoidance behavior levels than participants in the control group after the 1-, 3-, and 6-month interventions (P < .05). The main effects of group and time factors were highly significant in the intervention group. There were significant interaction effects in group and time factors. CONCLUSIONS: AWWI effectively improved the level of HIV-related knowledge and reduced general stigmatizing attitudes and work avoidance behaviors among nurses based on self-reported data in a tertiary hospital in China during a 6-month period.

Ganoderic acid A attenuated hepatic impairment by down-regulating the intracellular JAK2-STAT3 signaling pathway in induced mushroom poisoning.

BACKGROUND: Mushroom poisoning is one of the most prominent public health problems. However, there is no special antidote so far. In the present study, we verified that Ganoderma lucidum may be an effective approach for treatment of acute mushroom poisoning. METHODS: A retrospective study was performed within the past 20 years, we compiled information on the treatment of α-Amatoxin mushroom poisoning with Ganoderma lucidum by evaluating the mortality rate and liver function before and after treatment. Moreover, we explore the potential underlying mechanism of Ganoderma lucidum in the treatment of α-amanita poisoning in both in vivo animal experiments and in vitro cell experiments. RESULTS: In our study, a total of 556 cases of mushroom poisoning were integrated over the past 20 years, the primary outcome was in-hospital mortality. Specificity, descriptive data of ALT, AST, BA and STB were evaluated for the effectiveness of protection to acute liver damage. From 1994 to 2002, there were 55 cases of mushroom poisoning in which 372 individuals were poisoned, 129 individuals died, with a mortality of 35%. Since 2002, after being treated with Ganoderma lucidum, surprisingly, the mortality decreased to 0%, and all the 184 patients were cured, the hepatic impairment improved significantly within 10 days. Based on a multivariate logistic regression analyses, after adjusting for age, gender and baseline clinical indicators, it was found that Ganoderma lucidum treatment was effective in reducing the morbidity (OR = 0.58), and Ganoderma lucidum treatment also showed an improvement in liver enzymes and in shortening the length of hospitalization significantly. Meanwhile, the main components of Ganoderma lucidum, Ganoderic acid A could significantly improve the survival rate and liver function in α-Amatoxin poisoned mice and may effectively inhibit the JAK2-STAT3 pathway, which could contribute to the detoxification in poisoned patients. CONCLUSION: Ganoderma lucidum is very effective in treating mushroom poisoning by α-amanita and is worth promoting.

The Impacts of Narrative Perspectives of Anti-Prescription Opioid Campaigns: The Mediating Roles of Identification, Perceived Severity, and Anticipated Guilt.

An online experiment with two between-subjects conditions was conducted among a convenience sample of American college students to test the impact of first-person internally focalized versus third-person externally focalized risk narratives on the effectiveness of anti-prescription opioid campaigns as well as factors that explain such impact. It found that first-internal vs. third-external narratives increased identification with the character, perceived severity of the dangers of prescription opioids, anticipated guilt, as well as negative attitudes toward prescription opioids. The study also found indirect positive impacts of first-internal vs. third-external narratives on negative attitudes toward prescription opioids and intentions to avoid (mis)using prescription opioids via perceived severity and anticipated guilt but not identification. The findings contribute to our understanding of the impacts of narrative perspectives in the context of health communication and provide guidance in the design of effective anti-prescription opioid campaigns.

Safety and neutralization antibody levels of inactivated SARS-CoV-2 vaccine in adult patients with Myasthenia Gravis: a prospective observational cohort study.

BACKGROUND AND OBJECTIVES: Myasthenia gravis (MG) is an autoimmune disease affecting the neuromuscular junction. No cohort study has investigated the efficacy of inactivated vaccines in patients with MG. MATERIALS AND METHODS: This prospective observational cohort study included healthy controls (HCs) and patients with MG with or without immunosuppressive treatment. Vaccination occurred between May and December 2021. Patients with MG were subjected to a clinical scale assessment for disease severity. The neutralization antibodies (Nabs) levels were measured in all participants using the pseudovirus neutralization assay. RESULTS: Twenty-one patients (Female/Male:10/11); age median [interquartile range (IQR)]: 43 [30, 56]) were included in this study. Two patients (2/21) were lost during follow-up after enrollment. No sustained vaccine-related adverse effects occurred in any visit of patients with MG. No exacerbation of MG was observed. Acetylcholine receptor antibody (AChR-Ab) levels showed no statistically significant changes between the first and second visit (median [IQR]: 2.22 [0.99, 2.63] nmol/L vs. 1.54 [1.07, 2.40] nmol/L, p = 0.424). However, levels of AChR-Ab decreased at the third visit (median [IQR]: 2.22 [0.96, 2.70] nmol/L vs. 1.69 [0.70, 1.85] nmol/L, p = 0.011). No statistically significant difference in Nabs levels was found between HCs and patients with MG (median [IQR]: 102.89 [33.13, 293.86] vs. 79.29 [37.50, 141.93], p = 0.147). DISCUSSION: The safety of the SARS-CoV-2 inactivated vaccine was reconfirmed in this study. No significant difference in Nabs level was found between patients with MG and HCs. Nabs levels correlated with AChR-Ab levels before vaccination and ΔAChR-Ab levels.

Comparisons of nonpharmaceutical analgesia and pharmaceutical analgesia on the labor analgesia effect of parturient women.

OBJECTIVE: We aimed to compare the labor analgesia effects of nonpharmaceutical analgesia and pharmaceutical analgesia on parturient women. METHODS: One hundred and four parturient women with spontaneous births were selected and randomly divided into pharmaceutical and nonpharmaceutical analgesia groups. Before and after analgesia, the Visual Analogue Scale (VAS), parturient satisfaction with analgesia, serum pain stress factors (substance P [SP], neuropeptide Y [NPY], nerve growth factor [NGF], and prostaglandin E2 [PGE2]), duration of labor, vaginal bleeding at 2 h postpartum, postpartum urinary retention and dysuria incidence, Apgar score of 1 min and 5 min after birth, and neonatal cord blood gas analysis (pH, partial pressure of oxygen [PO2 ], partial pressure of carbon dioxide [PCO2 ], and lactate [Lac]) were compared in the two groups. RESULTS: VAS scores were lower and the analgesia satisfaction was higher in the pharmaceutical analgesia group than in the nonpharmaceutical analgesia group (all p < .05). Serum levels of SP, NPY, NGF, and PGE2 in the pharmaceutical analgesia group were lower than those in the nonpharmaceutical analgesia group (all p < .05). The first and second stages of labor were longer and the bleeding volume at 2 h postpartum was greater in the pharmaceutical analgesia group than those in the nonpharmaceutical analgesia group (all p < .05). Reduced Lac and PCO2 levels and increased PO2 level were found in the pharmaceutical analgesia group in comparison to the nonpharmaceutical analgesia group (all p < .05). CONCLUSION: This study demonstrates that the analgesic effect and neonatal condition of the pharmaceutical analgesia are better than the nonpharmaceutical analgesia, but the labor duration and postpartum bleeding volume of the pharmaceutical analgesia are greater than those of the nonpharmaceutical analgesia.

The impact of organizational justice on psychological distress among Chinese public hospitals nurses: A cross-sectional study.

Few studies have explored the association between organizational justice and mental health, particularly in collectivist countries. Hence, the aim of the present study was to evaluate the impact of organizational justice on psychological distress and to discuss the findings in collectivist culture. A cross-sectional survey was conducted among nurses from public hospitals in western of China, July 2022, which followed the STROBE guidelines. This study used Chinese versions of the Organizational Justice Scale and Kesseler Psychological Distress Scale to assess the perceptions of organizational justice and mental health levels, respectively. A total of 663 nurses completed the questionnaires. The psychological distress of university-educated and low-income nurses was poor. There was a moderately positive relationship between organizational justice and psychological distress (R = 0.508, P < .01), indicating that the greater level of organizational injustice, the poorer mental health. Hierarchical regression analysis showed that organizational justice was an strong predictor of psychological distress, accounting for approximately 20.5% of the psychological distress. The findings of this study highlight the importance of interpersonal injustice and distributive injustice on psychological distress specific in Chinese culture, suggesting that nursing management or leaders should notice that the most being taken seriously by nurses is their recognition and respect for subordinate, meanwhile, alerting nurses, in some sense, a negative relationship with leaders as a kind of workplace bullying could harm their mental health. The promulgation of organizational justice policy to protect employees from the government and the real role of employee labor union organizations are urgently needed.

A Highly Sensitive and Specific Detection Method for Mycobacterium tuberculosis Fluoroquinolone Resistance Mutations Utilizing the CRISPR-Cas13a System.

Objectives: CRISPR-Cas13a system-based nucleic acid detection methods are reported to have rapid and sensitive DNA detection. However, the screening strategy for crRNAs that enables CRISPR-Cas13a single-base resolution DNA detection of human pathogens remains unclear. Methods: A combined rational design and target mutation-anchoring CRISPR RNA (crRNA) screening strategy was proposed. Results: A set of crRNAs was found to enable the CRISPR-Cas13 system to dramatically distinguish fluroquinolone resistance mutations in clinically isolated Mycobacterium tuberculosis strains from the highly homologous wild type, with a signal ratio ranging from 8.29 to 38.22 in different mutation sites. For the evaluation of clinical performance using genomic DNA from clinically isolated M. tuberculosis, the specificity and sensitivity were 100 and 91.4%, respectively, compared with culture-based phenotypic assays. Conclusion: These results demonstrated that the CRISPR-Cas13a system has potential for use in single nucleotide polymorphism (SNP) detection after tuning crRNAs. We believe this crRNA screening strategy will be used extensively for early drug resistance monitoring and guidance for clinical treatment.

Effect of Moderate-to-Severe Iodine Deficiency in Early Pregnancy on Subclinical Hypothyroidism: A Longitudinal Study in an Iodine-Sufficient Region in China.

Objective: To investigate iodine status among pregnant women in an iodine-sufficient region in China after the implementation of revised universal salt iodization (USI) standards in 2012 and assess the association between urinary iodine concentrations (UIC) in early pregnancy and the incidence of subclinical hypothyroidism (SCH) in euthyroid women negative for antithyroid Ab during different trimesters. Methods: We measured the iodine status of 1,264 pregnant women, and performed follow-up assessment of thyroid function at 20 and 30 weeks of gestation among a cohort of 250 euthyroid women. We assessed the association of UIC in the 1st trimester with the incidence of SCH in subsequent trimesters. UIC and serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured. Results: The median UIC was 135.95 µg/L among 1,264 women. Serum FT4 level was significantly higher in the group of UIC 150 to 249 µg/L compared with other UIC groups (P < 0.001). TSH was significantly higher in the UIC more than or equal to 250 µg/L group than the UIC 150 to 249 g/L group (P = 0.043). Of the 250 euthyroid women negative for antithyroid Ab (TSH value of 2.5-3.55 mU/L) in the 1st trimester, pregnant women with UIC lower than 100 µg/L in the 1st trimester exhibited a significantly increased risk of SCH (odds ratio [OR] = 2.47; 95% confidence interval [CI] = 1.22-5.71; P = 0.012, according to the Chinese Medical Association criteria; OR = 5.22, 95% CI = 1.73-6.09, P = 0.004, according to ATA criteria) during the latter half of pregnancy compared with the UIC 150 to 249 µg/L group. Conclusion: Moderate-to-severe iodine deficiency (UIC lower than 100 µg/L) in the 1st trimester was associated with a significantly higher risk of SCH during the 2nd or 3rd trimesters among euthyroid pregnant women who had negative for antithyroid Ab. Women with SCH during pregnancy require regular UIC tests to maintain appropriate iodine status.

Is a single dose of commonly used antibiotics effective in preventing maternal infection after cesarean section? A network meta-analysis.

OBJECTIVE: This study aimed to compare the efficacy of different antibiotic classes and dosages in preventing maternal infection after cesarean delivery. METHODS: Databases were searched for randomized controlled trials (RCTs) published between January 1980 and January 2021 on antibiotic use for the prevention of maternal infection after cesarean delivery. The outcomes were endometritis, febrile morbidity, and wound infection, reported as odds ratios (OR) and surface under the cumulative ranking curve analysis scores. RESULTS: A total of 31 RCTs met the inclusion criteria. In the network meta-analysis (NMA) for endometritis, pooled network OR values indicated that the following interventions were superior to placebo: cephalosporins (OR: 0.18, 95% credibility interval [CrI]: 0.07-0.45), penicillins (OR: 0.19, 95% CrI: 0.07-0.50), penicillins (multiple doses) (OR: 0.20, 95% CrI: 0.05-0.65), combination therapies (OR: 0.22, 95% CrI: 0.09-0.54), and cephalosporins (multiple doses) (OR: 0.25, 95% CrI: 0.08-0.74). In the NMA for febrile morbidity, placebo was more effective than the other interventions. In the NMA for wound infection, pooled network OR values indicated that the following interventions were superior to placebo: penicillin (OR: 0.14, 95% CrI: 0.05-0.37), cephalosporins (OR: 0.19, 95% CrI: 0.08-0.41), cephalosporins (multiple doses) (OR: 0.20, 95% CrI: 0.06-0.58), combination therapies (OR: 0.29, 95% CrI: 0.13-0.57), macrolides (OR: 0.33, 95% CrI: 0.15-0.74), and penicillins (multiple doses) (OR: 0.40, 95% CrI: 0.17-0.91). CONCLUSIONS: Compared with placebo, a single dose of commonly used antibiotics may prevent maternal infection after cesarean delivery. However, the incidence of febrile morbidity was not reduced.

Start-up of co-digestion of poultry litter and wheat straw in anaerobic sequencing batch reactor by gradually increasing organic loading rate: Methane production and microbial community analysis.

Anaerobic co-digestion (ACoD) of poultry litter (PL) and wheat straw (WS) in an anaerobic sequencing batch reactor (ASBR) for continuous bio-energy generation was started up for the first time by gradually increasing the organic loading rate (OLR). A steady-state was reached with a daily biogas production of (13.06 ± 0.21) L and methane content of (54.38 ± 0.53) %. The subsequent regular operation achieved a daily methane yield of (100.41-188.65) mL CH4/g VS added and a total chemical oxygen demand (tCOD) removal rate of (70.3-85.9) % in the effluent under different operating parameters. The overall microbial community became more uniform, and the dominant aceticlastic methanogen of Methanosaeta was enriched after the start-up. While the microbial community was largely stable in the overall structure since the regular operation. Therefore, the start-up of the ACoD of PL and WS was successful with stable and continuous methane production.

The Anxiety Factor: Moral Traditionalism, Interpersonal Contact Diversity and Support for Transgender Candidates and Rights.

Given the prejudice against transgender people and the setbacks faced by transgender political candidates, an online survey was conducted (among a convenience sample of American adults recruited through Amazon Mechanical Turk) to investigate what influence public support for transgender candidates and rights and how to increase such support. The study found that moral traditionalism was negatively associated with support for transgender candidates and rights. The diversity of interpersonal contact with transgender individuals not only was positively related to the support but undermined the negative relationships between moral traditionalism and the support. More importantly, the study showed that anxiety toward transgender people mediated all the relationships observed here. These findings not only indicate how and why moral traditionalism and interpersonal contact diversity may affect public opinion toward transgender candidates and rights but also suggest ways to increase public support for transgender candidates and rights.

Immune memory in convalescent patients with asymptomatic or mild COVID-19.

It is important to evaluate the durability of the protective immune response elicited by primary infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we systematically evaluated the SARS-CoV-2-specific memory B cell and T cell responses in healthy controls and individuals recovered from asymptomatic or symptomatic infection approximately 6 months prior. Comparatively low frequencies of memory B cells specific for the receptor-binding domain (RBD) of spike glycoprotein (S) persisted in the peripheral blood of individuals who recovered from infection (median 0.62%, interquartile range 0.48-0.69). The SARS-CoV-2 RBD-specific memory B cell response was detected in 2 of 13 individuals who recovered from asymptomatic infection and 10 of 20 individuals who recovered from symptomatic infection. T cell responses induced by S, membrane (M), and nucleocapsid (N) peptide libraries from SARS-CoV-2 were observed in individuals recovered from coronavirus disease 2019 (COVID-19), and cross-reactive T cell responses to SARS-CoV-2 were also detected in healthy controls.

Seeking for an optimal strategy to avoid arsenic and cadmium over-accumulation in crops: Soil management vs cultivar selection in a case study with maize.

Soil management and cultivar selection are two strategies to reduce the accumulation risk of heavy metals in crops. However, it is still an open question which of these two strategies is more efficient for the safe utilization of contaminated soil. In this study, the available bio-concentration factors (aBCF) of arsenic (As) and cadmium (Cd) among 39 maize cultivars were determined through a field experiment. The effect of soil management was mimicked by choosing diverse sampling sites having different soil available contents of As and Cd. The aBCF of As and Cd in grain ranged from 0.02 to 0.13 and 1.17 to 42.2, respectively. The accumulation ability of As and Cd was classified among different maize cultivars. Soil pH and total As controlled the level of available As in soils, while soil pH dominated available Cd in soil. A soil pH of 6.5 was recommended to simultaneously minimize soil available As and Cd by managing soil conditions. The quantitative effects of cultivar and soil management on grain As and Cd were expressed as Q [Grain As] = 0.746Q [Cultivar]-0.126Q [pH]+0.276Q [Asavailable] (R2 = 0.648, P = 1.00 × 10-37) and Q [Grain Cd] = 0.913Q [Cultivar]-0.192Q [pH]+0.071Q [SOC] (R2 = 0.782, P = 1.00 × 10-37), respectively. Cultivar selection contributed stronger than soil management to decrease the As and Cd levels in maize grains. A feasible method to seek for a more efficient strategy was proposed for the safe utilization of contaminated soil.

Seeing is Believing: The Impacts of Visual Exemplars on American Young Adults' Reactions to Anti-Prescription Opioid Campaigns.

Many public health campaigns are designed to combat the opioid crisis in America. However, these campaigns are often ineffective or even counterproductive. To explore what contributes to the (in)effectiveness of these campaigns, an online experiment was conducted among a convenience sample of college students to test American young adults' reactions to four anti-prescription opioid campaign messages from local and national health organizations that vary in the presence of visual exemplars and statistical information. The study found that including a visual exemplar showing the negative consequences of misusing prescription opioids increased perceived susceptibility, psychological reactance, and perceived campaign effectiveness. The impacts of visual exemplars on psychological reactance and perceived campaign effectiveness were moderated by statistical information and (partially) explained by the believability of the campaigns.

[Investigation of anxiety and depression in patients from the emergency department during COVID-19 epidemic].

OBJECTIVE: To investigate the status of anxiety and depression in patients requiring emergency treatment during the epidemic of COVID-19 to identify the patients with acute psychological stress disorder. METHODS: During the COVID-19 epidemic, the medical staff divided the patients visiting the emergency department into suspected group, fever group and control group through interview of the patients at triage. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were distributed to each patient, and a trained medical staff was responsible for assisting the patient to complete the scales. RESULTS: A total of 557 sets of scales were distributed, including 211 in suspected COVID-19 case group, 167 in fever group and 179 in the control group. A total of 516 scales were retrieved, including 197 in suspected case group, 151 in fever group and 168 in control group. In the 3 groups, the incidence rates of anxiety and depression were 57.87% and 58.88%, 48.34% and 43.71%, and 18.31% and 18.99%, respectively, and the rates were significantly higher in suspected group and fever group than in the control group (P < 0.01), and significantly higher in suspected group than in fever group (P < 0.05). The standardized anxiety and depression scale scores in suspected case group, fever group and control group were 57.38±16.25 and 42.58±14.27, 51.23±15.29 and 38.32±15.39, and 32.58±17.8 and 12.25±12.94, respectively. Compared with the control group, both suspected case group and fever group had significantly higher standard scores for anxiety and depression (P < 0.01), and suspected case group had significantly higher standardized scores than fever group (P < 0.01). CONCLUSIONS: Among the patients visiting the emergency treatment, the patients with suspected COVID-19 and common fever are more likely to develop anxiety and depressive symptoms.

Demands and countermeasures for outpatients and emergency patients during the outbreak of coronavirus disease 2019 in large general hospital. / 大型综合性医院2019å† çŠ¶ç— æ¯’ç— ç–«æƒ æœŸé—´é—¨æ€¥è¯Šæ‚£è€ å°±è¯Šéœ€æ±‚åŠåº”å¯¹.

OBJECTIVES: To discuss the demands and countermeasures for outpatients and emergency patients during the outbreak of coronavirus disease 2019 (COVID-19) in large general hospital. METHODS: By analyzing patients' demands, outpatient service system and emergency system complemented each other with the help of "internet medical" to provide online medical treatment, self-diagnosed pneumonia program, online pharmacies, outpatient appointment and online pre-examination services, open green channels for special patients, and to provide referral services for critical patients. The COVID-19 suspected patients and other common fever patients were separated from other patients. RESULTS: From January 28 to March 1, we have received 26 000 patients online, 1 856 special patients, 2 929 suspected patients and common fever patients including 31 confirmed patients, 0 case of misdiagnosis and cross-infection. CONCLUSIONS: Targeting patient's demands and taking appropriate measures are effective on meeting the needs of outpatients' and emergency patients' medical services.

Young Adults' (Mis)use of Prescription Opioid Drugs: An Exploratory Study.

Based on Social Cognitive Theory (SCT) and the Risk Perception Attitude (RPA) Framework, this study used a survey to examine various factors affecting the risk perception and behavior related to prescription opioid drug (POD) misuse among college students. The results showed that trait reactance, helicopter parenting, and peer pressure were negatively associated with risk perception and positively correlated with POD misuse. Self-efficacy, on the other hand, was positively linked with risk perception and negatively connected with POD misuse. Risk perception was negatively correlated with POD misuse. In addition, self-efficacy moderated the relationship between risk perception and the misuse. This study extends the purview of both SCT and the RPA by testing their central predictions among a sample of a demographic group most vulnerable to the opioid epidemic. It also sheds light on the development of more effective prevention and intervention efforts to counter this burgeoning crisis. Limitations and directions for future research were outlined.

Evaluation of the antibacterial activity of tilmicosin-SLN against Streptococcus agalactiae: in vitro and in vivo studies.

BACKGROUND: Streptococcus and Staphylococcus are the major contagious organisms causing dairy cow mastitis. Our previous studies have demonstrated that solid lipid nanoparticles (SLNs) can effectively enhance the antimicrobial activity of tilmicosin against Staphylococcus. This study aimed to evaluate the antibacterial efficacy of tilmicosin-loaded SLN (Til-SLN) against Streptococcus agalactiae. METHODS: Til-SLN was prepared using a hot homogenization and ultrasonication method as described previously. Til-SLN was labeled with rhodamine B for nanoparticle tracking. In vitro antibacterial experiments were carried out by broth dilution technique. Pharmacokinetics of the drug and distribution of the nanoparticles in mammary gland were studied after subcutaneous injection in Kunming mice. The therapeutic study was conducted in a mouse mastitis model infected with S. agalactiae. RESULTS: The results showed that the diameter, polydispersity index, zeta potential, encapsulation efficiency, and loading capacity of the nanoparticles were not significantly affected by fluorescence labeling. Til-SLN showed a sustained and enhanced antibacterial activity in vitro. Til-SLN maintained a sustained drug concentration above 17 µg/g for at least 6 days in the mammary gland, as compared with only 3 days for the same amount of tilmicosin phosphate solution. The mean residence time and elimination half-life (T1/2) of Til-SLN were much longer than those of tilmicosin phosphate solution. Most of the nanoparticles remained at the injection site and a few were transferred to the mammary glands, indicating that the drug was slowly released at the injection site and then distributed to the mammary glands. SLN significantly enhanced the therapeutic efficacy of tilmicosin as determined by lower colony forming unit counts. CONCLUSION: These results demonstrate that SLN could effectively enhance the antibacterial activity of tilmicosin against Streptococcus.