Prevalence, resistance phenotypes, and fluoroquinolone resistance genes of Salmonella isolates from raw milk of healthy dairy cows in Henan province, China.

OBJECTIVE: Salmonella isolates have been discovered in many regions of the world. We investigated the prevalence and resistance of Salmonella isolates in raw milk of healthy dairy cows on farms in different regions of Henan Province, China. MATERIALS AND METHODS: From July 2020 to November 2021, 422 raw milk samples were collected. The minimum inhibitory concentrations (MICs) of 16 antimicrobial agents against 89 Salmonella strains detected from the raw milk samples were determined using the broth microdilution method, and the resistance genes for fluoroquinolones were identified using polymerase chain reaction. RESULTS: Eighty-nine (21.09%) Salmonella isolates were recovered from 422 raw milk samples. The Salmonella strains exhibited high resistance to amoxicillin (100.00%), tylosin (95.50%), and lincomycin (95.50%). Additionally, tigecycline showed good activity against Salmonella, with an MIC50 of 0.25 µg/mL. All Salmonella isolates showed multidrug resistance (MDR), and >50% of the strains showed resistance to more than six antimicrobials. The strains from Jiaozuo exhibited 100% resistance to amoxicillin, terramycin, tylosin, and lincomycin. Two efflux pump genes, oqxA and oqxB, had the highest carrying rates of 66.29% and 64.04%, respectively. Additionally, the carrying rates of oqxA and oqxB were high in Shangqiu, Zhengzhou, and Jiaozuo. The carrying rates of aac(6')-Ib-cr in Shangqiu and Zhengzhou were 33.33% and 38.46%, respectively. CONCLUSIONS: This study revealed a high prevalence of Salmonella isolates obtained from raw milk of healthy dairy cows in different regions of Henan Province, China. The Salmonella strains exhibited various degrees of MDR. Salmonella can be transmitted to humans via consumption of contaminated raw milk; thus, the presence of resistance genes poses a potential threat to public health, highlighting the need for vigilant monitoring of Salmonella isolates.

Antimicrobial mechanisms of traditional Chinese medicine and reversal of drug resistance: a narrative review.

OBJECTIVE: In recent years, the extensive use of antibiotics worldwide has led to an increase in the number of drug-resistant bacterial strains, thus resulting in an increasingly severe degree of bacterial resistance. For thousands of years, traditional Chinese medicine (TCM) has provided natural and unique advantages in the treatment of infectious diseases. Therefore, it is important to develop further and use TCM to treat clinical infections caused by drug-resistant bacteria. MATERIALS AND METHODS: A literature search was performed using PubMed, Web of Science, Google Scholar, and the China National Knowledge Infrastructure databases. The articles were analyzed to extract information on the antimicrobial effects of Chinese herbal medicines, compounded Chinese medicines, monomeric compounds of herbal origin, and the combined use of Chinese medicine and antimicrobial drugs and to determine the synergistic effect of the combination of Chinese medicine and antibiotics, as well as investigate the possibility of restoring the antibiotic sensitivity of drug-resistant strains. RESULTS: The mechanisms underlying the antibacterial properties of TCM involve altering membrane permeability, inhibiting protein and nucleic acid synthesis, inhibiting enzyme activity in vivo, and controlling the ability of pathogenic bacteria. In addition, the mechanism underlying TCM-induced reversal of bacterial drug resistance is discussed, particularly in terms of the elimination of resistant (R) plasmids and the inhibition of extended-spectrum ß-lactamases, bacterial biofilm formation, and bacterial efflux pump activity. CONCLUSIONS: This paper reviewed the recent relevant literature on antimicrobial action and its mechanisms, as well as the mechanisms of drug resistance reversal by TCM to provide a reference for clinical drug use, prevention and control of bacterial infection, and research and development of new drugs.

Efficacy of liposomal bupivacaine vs. traditional anaesthetic infiltration for pain management in total hip arthroplasty: a systematic review and meta-analysis.

In this review, we assess the effectiveness of liposomal bupivacaine against the traditional bupivacaine infiltration in the postoperative management of total hip arthroplasty (THA). Various databases including PubMed Central, Medline, Scopus, Embase, Google Scholar, Cochrane library and ScienceDirect (inception date till August 2020) were searched. The quality of published trials was assessed using Cochrane risk of bias tool, and a random-effects model was used for meta-analysis. We report pooled Risk ratios (RR) or pooled Standardized Mean difference (SMD) with 95% confidence intervals (CIs). We analyzed a total of 13 studies with 62,582 participants. The majority of the studies were retrospective with lower bias risks. Liposomal bupivacaine was significantly associated with the reduction in opioid requirement at 48 hours (SMD = -0.25; 95% CI: -0.40 to -0.09; p=0.002) and length of hospital stay (SMD = -0.25; 95% CI: -0.43 to -0.07, p=0.006) following THA compared with the control group. However, there was no statistically significant difference between the effect of liposomal bupivacaine and other agents for pain score (24 and 48 hours), opioid requirement at 24 hours and incidence of nausea. Liposomal bupivacaine has selective benefits in terms of opioid consumption and length of hospital stay against the traditional bupivacaine among the patients undergoing THA.

Research progress on the oxazolidinone drug linezolid resistance.

OBJECTIVE: The oxazolidinone drug linezolid is mainly used for severe infections caused by multidrug-resistant Gram-positive bacteria. However, emerging linezolid resistance is aggravating difficulties in the treatment of certain infectious diseases. The objective of this review was to provide a reference for researchers and clinicians to be able to better face together the serious challenge of antimicrobial resistance. MATERIALS AND METHODS: A systematic literature search was performed using PubMed, Web of Science, Google Scholar, and the China National Knowledge Infrastructure (CNKI) database. The articles were scrutinized to extract information on oxazolidinone drug linezolid resistance, and the prevalence of the resistance gene optrA. We reviewed the latest advances in epidemic properties, resistance mechanism, and transfer mechanism of linezolid resistance genes in different isolates isolated from various samples worldwide. RESULTS: Initially, it was thought that linezolid resistance was related to the change in drug target mediated by mutations in the 23S rRNA gene, rplC, rplD, and cfr. optrA was discovered in 2015, and is a gene encoding oxazolidinone resistance, which exists in both plasmids and chromosomes, but mostly plasmids. The emergence of the novel plasmid-borne ABC transporter gene optrA expanded the understanding of the mechanism of linezolid resistance. CONCLUSIONS: At present, the prevalence of linezolid resistance has become increasingly serious. The resistance gene optrA has been reported in Enterococcus, Staphylococcus squirrel and Streptococcus, which indicates that this gene has a strong ability to spread across bacteria, so the prevalence and spread of optrA gene should be monitored carefully.

Association between Changes in Sagittal X-ray Measurements and Neck Extensor Muscle Atrophy after Cervical Laminoplasty.

BACKGROUND: To investigate the association between neck extensor muscles (NEM) atrophy and changes in the sagittal cervical X-ray measurements after cervical laminoplasty. BASIC PROCEDURES: This retrospective analysis was conducted on 64 patients who underwent cervical laminoplasty from March 2016 to March 2019. The preoperative and postoperative sagittal cervical X-ray images were measured, including the C2-C7 cobb angle, the C2-7 sagittal vertical axis (SVA), and the angle between the plane of the upper endplate of T1 vertebra and the horizontal plane (T1 slope). The preoperative and postoperative steatosis ratios of the NEM were measured using magnetic resonance images. MAIN FINDINGS: There were significant differences between the preoperative and postoperative measurements of the C2-7 cobb angle, the C2-7 SVA, and the T1 slope (P<0.05). The preoperative and postoperative steatosis ratios of each intervertebral level of the NEM also differed significantly (P<0.05). The muscle atrophy ratio at C3/4 was positively correlated with the change in the C2-7 SVA (R=0.646, P<0.001) and negatively correlated with the change in the C2-7 cobb angle (R=-0.445, P<0.001). The muscle atrophy ratio at C7/T1 was positively correlated with the T1 slope (R=0.446, P<0.001). CONCLUSIONS: Muscle atrophy was more severe at the attachment points of the NEM (C3/4, C7T1). There was a significant association between the muscle atrophy ratio and the changes in sagittal cervical X-ray measurements.

[A novel trans-muscular approach for microsurgical bilateral decompression via unilateral approach for degenerative lumbar stenosis: a series study].

Objective: To compare clinical outcomes of microsurgical bilateral decompression via unilateral approach (MBDU) between trans longissimus and iliocostalis approach, a novel lateral paraspinal approach(LPA), and classic Wiltseapproach for single level degenerative lumbar stenosis. Methods: LPA approach was researched by imaging measurement and cadaver anatomy. Retrospective analysis of a total 124 cases(male/female 75/49, aged(55±14) years) received single-level MBDU due to degenerative lumbar stenosis from 2016 to 2018 in Beijing Tiantan Hospital. Patients were categorized into two groups according to spinal canal morphology. Group A: trefoil shape (n=48), received MBDU via LPA; Group B: round & oval shape (n=76), received MBDU via Wiltse approach. Clinical parameters, including visual analogue scale (VAS) of pain, OswestryDability Index (ODI), satisfaction rate were assessed before the operation and at the latest follow-up. The internal fixation and intervertebral fusion were evaluated by X-ray and CT.The data were compared with single sample t test between the two groups. Results: The feasibility of trans longissimus and iliocostalis approach was proved by imaging measurement and anatomic study. The tube's maximum tilt angle in LPA group was 65°, and it was 40°in Wiltse group. There was no significantly difference in the operating time, bleeding and drainage volume between the two groups((120±27) min vs (115±32) min, (104±31) ml vs (110±41) ml, (50±15) ml vs (47±18) ml, respectively, t=1.246,-1.917,1.730,all P>0.05). In both groups, VAS and ODI scores significantly improved at the latest follow-up when compared with those before the operation (all P<0.05), but those were all comparable between the two groups(all P>0.05). The excellent rate of subjective satisfaction for the clinical efficacy in group A and B was 89.6%(43/48) and 86.8%(66/76) respectively (χ(2)=0.208,P>0.05). Conclusions: LPA approachfor microsurgical bilateral decompression via unilateral approach (MBDU) in degenerative lumbar stenosis is safe and effective, it has advantages in direct vison of contralateral nerve root canal decompression for trefoil shaped spinal canal.

MicroRNA-31 inhibits papillary thyroid carcinoma cell biological progression by directly targeting SOX11 and regulating epithelial-to-mesenchymal transition, ERK and Akt signaling pathways.

OBJECTIVE: The current study aimed to explore the roles of miR-31 and SOX11 in papillary thyroid carcinoma (PTC). PATIENTS AND METHODS: Fifty-four paired human PTC specimens and matched normal thyroid tissues were obtained. Meanwhile, human thyroid epithelial cell Nthy-ori3-1 and PTC cells were cultured. The effects of miR-31 on PTC cell proliferation, invasion and migration were detected by cell proliferation assays and transwell assay, respectively. SOX11 expression in tissue samples was examined by immunohistochemical staining analyses (IHC). The correlation between SOX11 and miR-31 was clarified by Dual-Luciferase reporter assay. The relative mRNA and protein expression were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot. In addition, the xenograft model experiments were performed. RESULTS: Declined miR-31 expressions were frequently identified in PTC, leading to poorer overall survival (OS) and worse clinicopathologic features of PTC patients. Moreover, functional assays indicated that miR-31 overexpression could notably repress PTC cell proliferation, invasion and migration abilities by regulating the extracellular regulated protein kinases (ERK) and protein kinase B (Akt) signaling pathways and epithelial-mesenchymal transition (EMT). In addition, the results of the Luciferase reporter assay demonstrated that SOX11 was a direct functional target of miR-31 in PTC cells. In vivo, miR-31 restoration significantly suppressed the tumor growth of xenograft PTC models. CONCLUSIONS: Our findings indicated that miR-31 exerted anti-PTC functions via targeting SOX11 and modulating the ERK and Akt signaling pathways and EMT. MiR-31 may potentially serve as a novel biomarker in future therapeutics of PTC.

MicroRNA15b regulates apoptosis of cutaneous squamous cell carcinoma SCL-1 cell line: a mechanism study.

OBJECTIVE: Cutaneous squamous cell carcinoma is a malignant tumor, which is mostly common in skin epidermis or appendages. microRNA has been proved to regulate growth and survival of cells. Our study was focused on the effect of microRNA15b on cell viability and apoptosis of cutaneous squamous cell carcinoma SCL-1 cell line. MATERIALS AND METHODS: MicroRNA15b and control microRNA were synthesized and transfected into SCL-1 cells, respectively. Effects of transfection on SCL-1 cells were evaluated by MTT assays and flow cytometry. Western Blot was performed to examine the expression of survivin. MicroRNA15b-transfected SCL-1 cells were further intervened by siRNA targeting survivin or surviving-overexpressing plasmid. Their apoptosis were assessed by flow cytometry. RESULTS: Compared with control microRNA transfection, microRNA15b transfection significantly reduced cell viability, enhanced apoptosis and decreased protein expression of survivin. Inhibition of survivin expression enhanced microRNA15b-induced apoptosis of SCL-1 cells, while enhancement of survivin expression attenuated the apoptosis-promoting effect of microRNA15b on SCL-1 cells. CONCLUSIONS: MicroRNA15b reduced the cell viability and promoted the apoptosis of SCL-1 cells via down-regulating the expression of survivin. MicroRNA15b could be a potential therapeutic target for cutaneous squamous cell carcinoma.

[Relationship and clinical significance between mutated BRAF with prophylactic central-neck nodal dissection in papillary thyroid carcinoma].

OBJECTIVE: To evaluate the molecular diagnosis marker of papillary thyroid carcinoma (PTC), the relationship between lymphatic metastasis of central neck compartment PTC, and the operation indication of prophylactic central neck dissection. METHODS: We conducted a retrospective study, including 275 PTC patients and detected their BRAF mutation rates during 2012 and 2014 and explored the risk factors of the central node lymphatic metastasis by Logistic regression model. RESULTS: Of the 275 PTC patients, 224 (81.5%) were female and 51 (18.5%) were male. BRAF mutational rates were 53.8% (148/275) and lymphatic metastasis 57.8% (159/275). Multivariate analysis showed calcification (OR(adjusted)=1.47, 95%CI: 1.10-1.98, P=0.01), tumor diameter (OR(adjusted)=1.48, 95%CI: 1.04-2.30, P=0.048) and age (OR(adjusted)=1.48, 95%CI: 1.04-2.30, P=0.048) were associated with lymphatic metastasis. In stratified analysis, BRAF mutation (OR(adjusted)=3.19, 95%CI: 1.18-9.43, P=0.023) in clear boarder group and BRAF mutation (OR(adjusted)=4.84, 95%CI: 1.68-13.84, P=0.003) in calcification group were more likely to have lymphatic metastases. CONCLUSION: Central neck metastasis takes up a high ratio in papillary thyroid cancer patients, BRAF mutation in papillary thyroid carcinoma is a characteristic molecular event. Furthermore, patients with calcification under ultrasound detection, lower age group and longer tumor diameter are more susceptible to suffer central neck metastasis. Especially for stratified analysis, non-calcified BRAF mutation or BRAF mutation with clear border under ultrasound detection are more susceptible to suffer central neck metastasis, and radical prophylactic central neck dissection should be carried on for these patients.

Clinical application of carbon nanoparticle lymph node tracer in the VI region lymph node dissection of differentiated thyroid cancer.

The application and clinical significance of carbon nanoparticle lymph tracer in the VI region (central region) lymph node dissection of differentiated thyroid cancer was investigated. Eighty patients with differentiated thyroid cancer were equally divided into the carbon nanoparticle-marked group (ipsilateral thyroid injection) and the control group (no injection). All patients underwent standard primary tumor treatment and VI lymph node dissection. The number of lymph nodes retrieved in the carbon nanoparticle group (mean=6.725 pieces, range=1-13) was significantly higher than those retrieved in the control group (mean=3.6, range=1-7; P<0.05). The black staining lymph node rate was 69.89%. A significantly higher number of lymph nodes less than 2 mm were detected in the carbon nanoparticle group (P=0.0023). The transfer rates and lymph node metastasis rates did not differ significantly between the two groups. The black-staining lymph node metastasis rate was 20.74% (39/188) and the non-staining lymph node metastasis rate was 22.22% (18/81), which were not significantly different (P=0.7856). No parathyroid accidental resection was observed in the carbon nanoparticle group, whereas three cases occurred in the control group (P=0.2405). In conclusion, carbon nanoparticles show good lymphatic tracer effects, easy identification, increased number of lymph nodes retrieved, more accurate reflection of the VI region lymph node status, and increased accuracy of the clinical stage. These results should help develop reasonable surgery programs and follow-up comprehensive treatments, and can help to reduce the risk of accident parathyroid resection.

Phenotypic and molecular characterization of CTX-M-14 extended-spectrum ß-lactamase and plasmid-mediated ACT-like AmpC ß-lactamase produced by Klebsiella pneumoniae isolates from chickens in Henan Province, China.

Extended-spectrum ß-lactamases (ESBLs) and AmpC ß-lactamases produced by a clinical isolate of Klebsiella pneumoniae from chickens were detected with confirmatory phenotypic tests of the Clinical and Laboratory Standards Institute. The minimum inhibitory concentrations of 18 antibacterial drugs against K. pneumoniae were determined by the 2-fold microdilution method. The genotype and subtype of the ESBL-producing and AmpC ß-lactamase-producing K. pneumoniae isolate were identified by PCR amplification of the enzyme-encoding genes followed by DNA sequencing analysis. K. pneumoniae K(1) isolate was an ESBL-producing and AmpC ß-lactamase-producing bacteria with high resistance to ß-lactam antibiotics, such as penicillins, third-generation cephalosporins, fluoroquinolones, and aminoglycosides. The sequence analysis showed that K. pneumoniae K(1) harbored TEM-type, SHV-type, CTX-M-type, and ACT-type AmpC ß-lactamase nucleotide sequences. The TEM-type sequence was designated as TEM-1; the SHV-type sequence was designated as SHV-11; the CTX-M-type sequence was designated as CTX-M-14. Compared with the ACT-like sequence (EF078894), the ACT-type sequence was characterized by 8 nucleotide mutations (A(75)G, C(84)G, T(90)C, A(105)G, G(213)A, G(246)A, C(309)T, and T(315)C). Only one mutation at position 75 led to an amino acid substitution (Asn28Lys). The bla(ACT) type was an ACT-like derivative.

Clinical and economic analysis of hospital acquired infections in patients diagnosed with brain tumor in a tertiary hospital.

OBJECTIVES: To analyze the relationship between hospital acquired infections and clinical outcomes, duration of stay, and cost per infectious episode in patients diagnosed with brain tumors in our service. MATERIALS AND METHODS: We conducted a retrospective study on patients diagnosed with brain tumors and admitted to the department of neurosurgery in the Cruces Hospital of the University of the Basque Country between January 1st, 2007 and December 31st, 2007. We collected demographics, responsible pathogens, infection location, length of hospitalization, and costs of various medical and surgical procedures performed. RESULTS: We reviewed 139 patients that accumulated 210 hospital visits. We found 34 episodes of hospital acquired infections (16.25% of patients). The most frequent infections were that of the lower respiratory tract, urinary tract, and surgical site. We found that patients with HAIs had a significantly lower final KPS score (sig <0.01), greater mean cost of stay (17097 €, sig<0.01), and longer length of stay (15.45 days, sig<0.01). We did not find a significant difference in mortality. CONCLUSIONS: We found significant association between the presence of HAIs and worse clinical outcomes, higher costs, and longer length of stay. The pathogens responsible and infection locations were similar to existing series in the literature. Although variability in study designs in the literature makes interpretation and comparison of results difficult, measures to prevent these complications.

Clinical and economic analysis of hospital acquired infections in patients diagnosed with brain tumor in a tertiary hospital

Objectives. To analyze the relationship between hospital acquired infections and clinical outcomes, duration of stay, and cost per infectious episode in patients diagnosed with brain tumors in our service.Materials and methods. We conducted a retrospective study on patients diagnosed with brain tumors and admitted to the department of neurosurgery in the Cruces Hospital of the University of the Basque Country between January 1st, 2007 and December 31st, 2007. We collected demographics, responsible pathogens, infection location, length of hospitalization, and costs of various medical and surgical procedures performed.Results. We reviewed 139 patients that accumulated 210 hospital visits. We found 34 episodes of hospital acquired infections (16.25% of patients). The most frequent infections were that of the lower respiratory tract, urinary tract, and surgical site. We found that patients with HAIs had a significantly lower final KPS score (sig <0.01), greater mean cost of stay (17097€, sig.<0.01), and longer length of stay (15.45 days, sig<0.01). We did not find a significant difference in mortality.Conclusions. We found significant association between the presence of HAIs and worse clinical outcomes, higher costs, and longer length of stay. The pathogens responsible and infection locations were similar to existing series in the literature. Although variability in study designs in the literature makes interpretation and comparison of results difficult, measures to prevent these complications can improve quality of care and reduce costs (AU)

Objetivos. Analizar la relación entre la presencia de infección nosocomial y el resultado clínico final, la duración de la estancia y el coste del episodio en los pacientes diagnosticados de tumoración cerebral en nuestro servicio.Material y método. Realizamos un estudio retrospectivo incluyendo los pacientes ingresados en el Servicio de Neurocirugía del Hospital Universitario de Cruces con diagnostico de tumoración cerebral en el periodo comprendido entre el 1-1-2007 y el 31-12 del 2007. Recogimos variables demográficas, los microorganismos responsables y la localización de las distintas infecciones, el tiempo de ingreso y los costes de los distintos procedimientos médicos y quirúrgicos realizados.Resultados. Recogimos 139 pacientes, que acumularon un total de 210 episodios. Encontramos la presencia de infecciones nosocomiales en 34 episodios (16,25%). La localización mas frecuente fue la respiratoria, seguida del tracto urinario y la infección de herida quirúrgica. Encontramos unas diferencias significativas en la situación funcional al alta (sig <0.01), el coste medio de los episodios (17097€, sig.<0.01) y en la estancia media (15.45 días, sig.<0.01). No encontramos diferencias significativas con respecto a la mortalidad.Conclusiones. Encontramos asociaciones significativas entre la presencia de infección nosocomial, un peor resultado clínico, un mayor coste y una mayor estancia. Los gérmenes responsables y localizaciones fueron similares a las series previamente publicadas. A pesar de que la variabilidad en el diseño de los estudios recogidos en la literatura dificulta la interpretación y comparación de los resultados, las medidas destinadas a la prevención de esta complicación permiten simultáneamente mejorar la asistencia prestada, asi como reducir los costes generados por la enfermedad (AU)

Altered protein profile of lymphocytes in an antigen-specific model of colitis: a comparative proteomic study.

OBJECTIVE: Lymphocytes are deeply involved in the initiation and perpetuation of inflammatory response in inflammatory bowel disease (IBD) and lymphocyte-derived proteins are associated with the pathogenesis of the disease. The aim of this study was to identify the altered protein profiles of lymphocytes from rats with colitis. METHODS: Colitis models were induced by colonic administration of trinitrobenzene sulfonic acid (TNBS) in 50% ethanol in male SD rats. Seven days after administration of TNBS/ethanol, lymphocytes were harvested from mesenteric lymph nodes (MLNs) and proteins were extracted. Two-dimensional polyacrylamide gel electrophoresis and PDQuest 2D-image-analysis software were used to display and analyze the protein spots. The differentially-expressed proteins were identified by tryptic in-gel digestion and mass spectrometry. Real-time RT-PCR was used for selected transcripts to validate the findings of the proteomics analysis. RESULTS: A total of 1,100 protein spots including 26 proteins with at least a two-fold difference in abundance between colitis and control groups were identified. Among all the detected spots, 17 were up-regulated and 9 were down-regulated. It was found that the altered proteins included the regulators of the cell cycle and cell proliferation, signal transduction factors, inflammatory factors, apoptosis-related proteins and metabolic enzymes. CONCLUSIONS: In lymphocytes of rats with TNBS-induced colitis, 26 altered proteins were identified. They involve inflammation, apoptosis, metabolism, and regulation of the cell cycle, cell proliferation, and signal transduction.

Island shape selection in Pt(111) submonolayer homoepitaxy with or without CO as an adsorbate.

The microscopic selection mechanisms of single-layer island shapes in Pt(111) homoepitaxy with or without minute amounts of CO adsorbate have been investigated theoretically. For clean growth, only triangular islands of a fixed orientation are obtained within a wide range of growth temperatures, with the orientation uniquely determined by a disparity in the rates of atom supply to an island corner site from the two island edges defining the corner. This novel picture is further corroborated by growth predictions in the presence of CO, whose preferential decoration of one type of the island edges reverses the intrinsic rate disparity for atom supply, thereby inverting the island orientation.

Effects of bupivacaine and ropivacaine on high-voltage-activated calcium currents of the dorsal horn neurons in newborn rats.

BACKGROUND: Local anesthetics, such as bupivacaine, have been reported to block calcium currents in primary sensory neurons and to interfere with the release of neurotransmitters in central nervous system neurons. However, it is unknown whether local anesthetics affect the calcium current activity of central nervous system neurons. METHODS: Using a traditional whole cell voltage clamp technique, effects of bupivacaine and ropivacaine on high-voltage-activated calcium currents (HVA-Ic(a)) were investigated in enzymatically dissociated dorsal horn neurons of neonatal rats. Calcium currents were evoked by testing pulses from a holding potential of -90 to 0 mV. RESULTS: Bupivacaine significantly reduced HVA-Ic(a) in a dose-dependent manner. The peak HVA-Ic(a) decreased by 24.5+/-2.5, 32.0+/-6.8, 59.4+/-6.2, 88.3+/-1.5, and 91.6+/-1.1% in response to 10, 30, 50, 100 and 200 microM bupivacaine, respectively. Unlike bupivacaine, ropivacaine markedly increased HVA-Ic(a) at lower concentrations (< 50 microM) but decreased HVA-Ic(a) at higher concentrations (> or = 50 microM). The percent increases in peak HVA-Ic(a) induced by 10 and 30 microM ropivacaine were 95+/-19.1 and 41.6+/-8.3%, respectively. The percent decreases in response to 50, 100, and 200 microM ropivacaine were 21.1+/-2.1, 63.2+/-6.0 and 79.1+/-7.6%, respectively. Results indicate that the inhibitory potency of ropivacaine on HVA-Ic(a) was significantly lower than that of bupivacaine at the same concentrations. CONCLUSIONS: The current study showed that bupivacaine inhibited HVA-Ic(a) recorded from dorsal horn neurons and that ropivacaine increased HVA-Ic(a) at lower concentrations but decreased HVA-Ic(a) at higher concentrations. The inhibitory potency of ropivacaine was lower than that of bupivacaine. Inhibition of calcium currents of central nervous system neurons may be related to the systemic neurotoxic effects of local anesthetics (e.g., convulsions, seizures).

Decay characteristics of surface mounds with contrasting interlayer mass transport channels.

The decay characteristics of three-dimensional (3D) islands formed on surfaces are investigated theoretically considering two types of interlayer mass transport mechanisms. If an adatom on a given layer can easily descend from any site along the periphery of the layer, an optimal island slope and a constant terrace width will be selected during the decay. In contrast, if the adatom can descend primarily through selective (such as kinked) sites, the decay will be accompanied by a gradual increase in the island slope. These generic conclusions provide the basis for a microscopic understanding of the decay of nanostructures in fcc(111) and fcc(100) metal homoepitaxy and are applicable to other systems as well.

The effects of ropivacaine on sodium currents in dorsal horn neurons of neonatal rats.

We used a whole cell patch clamp technique to study the effects of ropivacaine on rat dorsal horn neurons. Under voltage clamp, ropivacaine (10-400 microM) produced a dose-dependent inhibition of sodium current. From a holding potential (V(h)) of -80 mV, sodium currents evoked by test pulses to 0 mV were inhibited by ropivacaine with a mean drug concentration required to produce 50% current inhibition (IC(50)) value of 117.3 microM, which was more than the value of the bupivacaine (IC(50) 53.7 microM). The inhibition effect of ropivacaine was also voltage-dependent. Current evoked from a V(h) of -60 mV was inhibited by ropivacaine with a mean IC(50) value of 74.3 microM, which was less than that obtained at the V(h) of -80 mV. The inhibition effect of ropivacaine on sodium current was use dependent. Repeated activation by a train of depolarizing pulses (5 Hz, 20 ms) increased the inhibitory effects of ropivacaine. The ratio amplitudes of the 20th to the first pulse were 91.2% and 71.1%, respectively, in the absence and presence of ropivacaine (50 microM). Ropivacaine also produced a significant hyperpolarizing shift of 11 mV in the steady-state inactivation curve of sodium current. The inhibition of ropivacaine on the sodium channel may contribute to the mechanism of action of local anesthetics during epidural and spinal anesthesia.

[Breast-feeding by mothers with positive serum hepatitis B virus test].

Sixty one samples of colostrum from mothers with positive serum Hepatitis B virus (HBV) test were collected and determined for serial HBV markers along with HBV DNA. Results showed that HBsAg, HBeAg and anti-HBc were most likely transferred by milk, while anti-HBs and anti-HBe had less possibility to enter the colostrum (P < 0.01). The overall HBV DNA positive rate was 42.6% in the 61 samples. The various HBV markers detected in mothers' serum presented a high consistency with those discovered in the corresponding milk samples. There were significantly higher rate of milk HBV transmission from mothers with serum positive HBsAg, HBeAg and anti-HBc or either one of them than those with positive for anti-HBs and/or anti-HBe.

[A clinical trial of radioimmunoguided surgery for gastric cancer].

A clinical trial of radioimmunoguided surgery (RIGS) using 131I labeled monoclonal antibody (McAb) 3H11 and a portable gamma-detector Oncoprobe II was performed on 25 cases with gastric cancer in this study. The 25 patients involved in the study included 4 for intravenous administration of 131I-3H11, 19 for injection of 131I-3H11 into submucosa by endoscope and 2 for receiving radiolabeled normal mouse IgG by endoscope as control. The sensitivity in detecting tumor infiltrated gastric wall was 94.6%, the specificity was 96.7% and the accuracy was 95.9%. For the detection of metastatic lymph nodes, the sensitivity of RIGS was 99.2%, the specificity was 97.7% and the accuracy was 98.8%. The results described above indicate that the RIGS system for gastric cancer is very promising for identification of the extent of tumor, metastatic lymph nodes and reasonable radical resection with higher curability and better life quality for patients.