ABSTRACT
Background@#The poor bioadhesion capacity of tilmicosin resulting in treatment failure for Staphylococcus aureus small colony variants (SASCVs) mastitis. @*Objectives@#This study aimed to increase the bioadhesion capacity of tilmicosin for the SASCVs strain and improve the antibacterial effect of tilmicosin against cow mastitis caused by the SASCVs strain. @*Methods@#Tilmicosin-loaded chitosan oligosaccharide (COS)-sodium carboxymethyl cellulose (CMC) composite nanogels were formulated by an electrostatic interaction between COS (positive charge) and CMC (negative charge) using sodium tripolyphosphate (TPP) (ionic crosslinkers). The formation mechanism, structural characteristics, bioadhesion, and antibacterial activity of tilmicosin composite nanogels were studied systematically. @*Results@#The optimized formulation was comprised of 50 mg/mL (COS), 32 mg/mL (CMC), and 0.25 mg/mL (TPP). The size, encapsulation efficiency, loading capacity, polydispersity index, and zeta potential of the optimized tilmicosin composite nanogels were 357.4 ± 2.6 nm, 65.4 ± 0.4%, 21.9 ± 0.4%, 0.11 ± 0.01, and -37.1 ± 0.4 mV, respectively; the sedimentation rate was one. Scanning electron microscopy showed that tilmicosin might be incorporated in nano-sized crosslinked polymeric networks. Moreover, adhesive studies suggested that tilmicosin composite nanogels could enhance the bioadhesion capacity of tilmicosin for the SASCVs strain. The inhibition zone of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels were 2.13 ± 0.07, 3.35 ± 0.11, and 1.46 ± 0.04 cm, respectively. The minimum inhibitory concentration of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels against the SASCVs strain were 2, 1, and 1 µg/mL, respectively. The in vitro time-killing curves showed that the tilmicosin composite nanogels increased the antibacterial activity against the SASCVs strain. @*Conclusions@#This study provides a potential strategy for developing tilmicosin composite nanogels to treat cow mastitis caused by the SASCVs strain.
ABSTRACT
Background@#The poor intracellular concentration of enrofloxacin might lead to treatment failure of cow mastitis caused by Staphylococcus aureus small colony variants (SASCVs). @*Objectives@#In this study, enrofloxacin composite nanogels were developed to increase the intracellular therapeutic drug concentrations and enhance the efficacy of enrofloxacin against cow mastitis caused by intracellular SASCVs. @*Methods@#Enrofloxacin composite nanogels were formulated by an electrostatic interaction between gelatin (positive charge) and sodium alginate (SA; negative charge) with the help of CaCl 2 (ionic crosslinkers) and optimized by a single factor test using the particle diameter, zeta potential (ZP), polydispersity index (PDI), loading capacity (LC), and encapsulation efficiency (EE) as indexes. The formation mechanism, structural characteristics, bioadhesion ability, cellular uptake, and the antibacterial activity of the enrofloxacin composite nanogels against intracellular SASCVs strain were studied systematically. @*Results@#The optimized formulation was comprised of 10 mg/mL (gelatin), 5 mg/mL (SA), and 0.25 mg/mL (CaCl2). The size, LC, EE, PDI, and ZP of the optimized enrofloxacin composite nanogels were 323.2 ± 4.3 nm, 15.4% ± 0.2%, 69.6% ± 1.3%, 0.11 ± 0.02, and −34.4 ± 0.8 mV, respectively. Transmission electron microscopy showed that the enrofloxacin composite nanogels were spherical with a smooth surface and good particle size distributions. In addition, the enrofloxacin composite nanogels could enhance the bioadhesion capacity of enrofloxacin for the SASCVs strain by adhesive studies. The minimum inhibitory concentration, minimum bactericidal concentration, minimum biofilm inhibitory concentration, and minimum biofilm eradication concentration were 2, 4, 4, and 8 μg/mL, respectively. The killing rate curve had a concentration-dependent bactericidal effect as increasing drug concentrations induced swifter and more radical killing effects. @*Conclusions@#This study provides a good tendency for developing enrofloxacin composite nanogels for treating cow mastitis caused by intracellular SASCVs and other intracellular bacterial infections.
ABSTRACT
Objective To observe and compare the effects of acupuncture and acupuncture plus speech therapy on activation of the brain areas in aphasic patients by use of oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI).Methods Twenty patients with aphasia caused by stroke were randomized into two groups by use of random number table (10 cases in each group):an experimental group subject to acupuncture treatment combined with speech therapy,and a control group subject to speech therapy only.All the cases were dextromanuality.On admission and after 1 month of treatment,BOLD-fMRI was used to test signals of the activated brain areas of both group,and Aphasia Battery of the Chinese (ABC) was employed to evaluate the changes of speech ability of the patients.Results During the study,1 case from control group was unable to do the post-intervention evaluation due to onset of the second stroke.The effective rates of the control and experimental group were 55.56％ and 100.00％,respectively,and recovery of verbal ability in experimental group was significantly better than in control group (P ＜ 0.05).The active volume and extent in brain were significantly increased in both groups (P ＜0.05),and a comparison between the two groups showed that the changes in activation volume and extent of the brain were significantly greater extensive in experimental group than in the control group,especially in bilateral frontal lobe,cuneus,posterior cingulate gyrus,lingual gyrus,occipital lobe,splenium of corpus callosum,cerebellar hemisphere,and the left precentral gyrus,post-central gyrus,paracentral lobule,temporal lobes,angular gyrus,precuneus,and the right hippocampus,parahippocampus gyrus.Conclusion Acupuncture combined with speech therapy could cause changes in activation patterns of the brain areas,which may contribute to the improvement of verbal ability of the aphasic patients.
ABSTRACT
Objective To explore brain activity features during the resting state in alcohol dependent individuals,and study the relationship between the brain activity features and alcohol dependent individuals' clinical symptoms.Methods Twenty-four alcohol dependent individuals and 22 healthy control subjects,well matched in gender,age,education and handedness,were enrolled as the alcohol dependent group and control group respectively.AGE 3.0 T MR scanner was used to acquire all the subjects' resting state data. DPARSF software was used to process resting functional MRI data,and then the whole brain fractional amplitudes of low frequency fluctuation (fALFF) data were acquired.Two-sample t test statistical analysis was made to access fALFF difference between the two groups. Results In comparison with the control group,the alcohol dependent group showed reduced fALFF in bilateral medial prefrontal gyrus,right inferior occipital gyrus,left precuneus,left inferior temporal gyrus,and left posterior lobe of cerebellum (0.64-1.69 vs.0.87-1.78,t =- 4.23- - 2.79,P ＜ 0.05 ). fALFF was increased in the alcohol dependent group at the anterior cingulate,bilateral inferior frontal gyrus,right middle frontal gyrus,bilateral insular lobe,bilateral dorsal thalamus ( 0.86-1.82 vs. 0.76-1.58,t =3.56-3.96,P ＜ 0.05 ).Conclusion Alcohol dependent individuals had abnormal activity at the bilateral prefrontal lobe,anterior cingulate,bilateral dorsal thalamus,bilateral insular lobe,left posterior lobe of cerebellum et al,during the resting state,and these abnormal activities might be related with clinical manifestation and pathophysiology.