Objective To evaluate the reliability of Vitek 2 AST-N335 card for determining the susceptibility of Acinetobacter bauman-nii(AB)to cefoperazone/sulbactam.Methods A total of 318 non-repeated clinical isolates of AB collected in 2023 were tested for antimicrobial susceptibility to cefoperazone/sulbactam using broth microdilution(BMD),the AST-N335 card,and the Kirby-Bauer(K-B)disk diffusion method.Using BMD as the reference method,the reliability of AST-N335 card was assessed,and the accuracy of K-B disk diffusion method as the confirmatory test was validated.Results Compared with BMD,the susceptibility testing of 318 AB strains to cefoperazone/sulbactam using the AST-N335 card showed categorical agreement(CA)of 87.8％(279/318),very major er-ror(VME)of 6.0％(19/318),major error(ME)of 0％(0/318),and minor error(mE)of 1.9％(6/318),which fall outside of the acceptable error range.In contrast,the K-B method achieved CA of 99.4％(316/318),VME of 0％,ME of 0.3％(1/318),and mE of 0.3％(1/318),all within acceptable limits.Of these,the errors with AST-N335 card occurred within the minimum inhibitory concentration(MIC)range of 8-32 μg/mL.Using BMD as the reference method,further analysis was performed on the 171 AB strains with AST-N335 card MIC values of 8-32 μg/mL for cefoperazone/sulbactam.It was revealed that at MIC of 32 μg/mL,the CA was 0％;at MIC of 16 μg/mL,CA was 5.3％(1/19)and VME rate was 84.2％(16/19),both of which substantially exceeded accepta-ble error ranges.At MIC of 8 μg/mL,the CA was 94.9％(131/138)and VME was 2.2％(3/138),both approaching the acceptable ranges.Conclusion The results obtained with Vitek 2 AST-N335 card in determining for cefoperazone/sulbactam are unreliable when the MIC values fall within the range of 8-32 μg/mL,which leads to an underestimation of the resistance rate to cefoperazone/sulbac-tam.This issue requires urgent attention in both laboratories and clinical practice.The K-B disk diffusion method could serve as a sup-plementary verification approach in routine laboratories.

Objective To evaluate the reliability of Vitek 2 AST-N335 card for determining the susceptibility of Acinetobacter bauman-nii(AB)to cefoperazone/sulbactam.Methods A total of 318 non-repeated clinical isolates of AB collected in 2023 were tested for antimicrobial susceptibility to cefoperazone/sulbactam using broth microdilution(BMD),the AST-N335 card,and the Kirby-Bauer(K-B)disk diffusion method.Using BMD as the reference method,the reliability of AST-N335 card was assessed,and the accuracy of K-B disk diffusion method as the confirmatory test was validated.Results Compared with BMD,the susceptibility testing of 318 AB strains to cefoperazone/sulbactam using the AST-N335 card showed categorical agreement(CA)of 87.8％(279/318),very major er-ror(VME)of 6.0％(19/318),major error(ME)of 0％(0/318),and minor error(mE)of 1.9％(6/318),which fall outside of the acceptable error range.In contrast,the K-B method achieved CA of 99.4％(316/318),VME of 0％,ME of 0.3％(1/318),and mE of 0.3％(1/318),all within acceptable limits.Of these,the errors with AST-N335 card occurred within the minimum inhibitory concentration(MIC)range of 8-32 μg/mL.Using BMD as the reference method,further analysis was performed on the 171 AB strains with AST-N335 card MIC values of 8-32 μg/mL for cefoperazone/sulbactam.It was revealed that at MIC of 32 μg/mL,the CA was 0％;at MIC of 16 μg/mL,CA was 5.3％(1/19)and VME rate was 84.2％(16/19),both of which substantially exceeded accepta-ble error ranges.At MIC of 8 μg/mL,the CA was 94.9％(131/138)and VME was 2.2％(3/138),both approaching the acceptable ranges.Conclusion The results obtained with Vitek 2 AST-N335 card in determining for cefoperazone/sulbactam are unreliable when the MIC values fall within the range of 8-32 μg/mL,which leads to an underestimation of the resistance rate to cefoperazone/sulbac-tam.This issue requires urgent attention in both laboratories and clinical practice.The K-B disk diffusion method could serve as a sup-plementary verification approach in routine laboratories.

Objective To investigate the mechanism by which Colony Stimulating Factor-1(CSF1)inhibits apoptosis in neurons subjected to oxygen-glucose deprivation(OGD).Methods Primary rat cortical neurons were divided into the OGD damaged neuron model group(OGD group),the rh-CSF1 intervention group(rh-CSF1 group),and control group.The sample size for each group was 3.After intervention with recombinant human CSF1(rh-CSF1),neuronal apoptosis rate and intracellular ATP content,reactive oxygen species levels,mitochondrial membrane potential,and mitochondrial DNA copy number were measured.The content of malondialdehyde within mitochondria and the activity of superoxide dismutase were also assessed.Results Intervention with rh-CSF1 increased mitochondrial membrane potential(0.55±0.03 vs.0.43±0.06,P<0.01),mitochondrial DNA copy number(0.88±0.05 vs.0.72±0.06,P<0.05),ATP content[(15.70±0.99)mmol/mg vs.(11.70±1.00)mmol/mg,P<0.01)],and superoxide dismutase[(18.47±1.38)U/mg vs.(14.78±1.81)U/mg,P<0.05)]activity in neurons injured by OGD.It also reduced levels of rectivereactive oxygen species(3.64±0.21 vs.4.45±0.33,P<0.05)and malondialdehyde within mitochondria[(2.13±0.19)mmol/mg vs.(2.78±0.20)mmol/mg,P<0.05)],and inhibited neuronal apoptosis(10.12±0.78 vs.17.04±1.23,P<0.01)Conclusion rh-CSF1 may alleviate the damage in neurons induced by OGD by improving mitochondrial function,reducing oxidative stress,and inhibiting cell apoptosis.

OBJECTIVES: To explore the physicochemical characteristics and biocompatibility of calcium peroxide (CPO)-loaded polycaprolactone (PCL) microparticle. METHODS: The CPO/PCL particles were prepared. The morphology and elemental distribution of CPO, PCL and CPO/PCL particles were observed with scanning electron microscopy and energy dispersive spectroscopy, respectively. Rat adipose mesenchymal stem cells were isolated and treated with different concentrations (0.10%, 0.25%, 0.50%, 1.00%) of CPO or CPO/PCL particles. The mesenchymal stem cells were cultured in normal media or osteogenic differentiation media under the hypoxia/normoxia conditions, and the amount of released O₂ and H₂O₂ after CPO/PCL treatment were detected. The gene expressions of alkaline phosphatase (ALP), Runt-associated transcription factor 2 (RUNX2), osteopontin (OPN) and osteocalcin (OCN) were detected by realtime RT-PCR. SD rats were subcutaneously injected with 1.00% CPO/PCL particles and the pathological changes and infiltration of immune cells were observed with HE staining and immunohistochemistry at day 7 and day 14 after injection. RESULTS: Scanning electron microscope showed that CPO particles had a polygonal structure, PCL particles were in a small spherical plastic particle state, and CPO/PCL particles had a block-like crystal structure. Energy dispersive spectroscopy revealed that PCL particles showed no calcium mapping, while CPO/PCL particles showed obvious and uniform calcium mapping. The concentrations of O₂ and H₂O₂ released by CPO/PCL particles were lower than those of CPO group, and the oxygen release time was longer. The expressions of Alp, Runx2, Ocn and Opn increased with the higher content of CPO/PCL particles under hypoxia in osteogenic differentiation culture and normal culture, and the induction was more obvious under osteogenic differentiation conditions (all P<0.05). HE staining results showed that the muscle tissue fibers around the injection site were scattered and disorderly distributed, with varying sizes and thicknesses at day 7 after particle injection. Significant vascular congestion, widened gaps, mild interstitial congestion, local edema, inflammatory cell infiltration, and large area vacuolization were observed in some tissues of rats. At day 14 after microparticle injection, the muscle tissue around the injection site and the tissue fibers at the microparticle implantation site were arranged neatly, and the gap size was not thickened, the vascular congestion, local inflammatory cell infiltration, and vacuolization were significantly improved compared with those at day 7. The immunohistochemical staining results showed that the expressions of CD3 and CD68 positive cells significantly increased in the surrounding muscle tissue, and were densely distributed in a large area at day 7 after particle injection. At day 14 of microparticle injection, the numbers of CD3 and CD68 positive cells in peripheral muscle tissue and tissue at the site of particle implantation were lower than those at day 7 (all P<0.01). CONCLUSIONS CPO/PCL particles have good oxygen release activity, low damage to tissue, and excellent biocompatibility.
Rats ; Animals ; Osteogenesis ; Core Binding Factor Alpha 1 Subunit ; Rats, Sprague-Dawley ; Hydrogen Peroxide/pharmacology* ; Cell Differentiation ; Oxygen ; Hypoxia ; Cells, Cultured

OBJECTIVETo detect potential mutations of the spastic ataxia of Charlevoix-Saguenay (SACS) gene in a pedigree affected with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS).

METHODSGenomic DNA was extracted from peripheral blood samples of the proband and her family members. All exons and flanking sequences of the SACS gene were analyzed by high-throughput sequencing. Suspected mutations were verified with Sanger sequencing.

RESULTSNext generation sequencing revealed novel compound heterozygous mutations of the SACS gene, namely c.13085T to G (p.I4362R) and c.5236dupA (p.T1746fs), in the proband, which were respectively derived from her parents. The mutations were confirmed by Sanger sequencing.

CONCLUSIONThe c.5236dupA (p.T1746fs) and c.13085T to G (p.I4362R) mutations of the SACS gene probably underlie the ocular symptoms and hearing loss in the proband.