Psychological stress reactions of occupational exposure to blood-borne infectious pathogens among medical staff: A longitudinal study / 中国心理卫生杂志

Objective:To probe into the status characteristics and the dynamic change trend of the psychological stress among medical staff at four time points after exposed to blood-borne pathogen.Methods:A longitudinal study was carried out among 78 medical personnel in this study,with 67 of hepatitis B virus,5 of hepatitis C virus,4 of HIV and 2 of treponema pallidum respectively.Perceived stress scale (PSS-4),Post-traumatic stress disorder Checklist-5 (PCL-5),Hospital anxiety and depression scale (HADS) were used to assess the psychological status,including perceived stress,post-traumatic stress symptom,anxiety and depression at the four times.Data analysis was performed using repeated measures analysis of variance (RMANOVA) and paired sample t test to explore time effect of the psychological stress reaction in the exposed population.Results:The scores of PSS-4,PCL-5,HADS-A,and HADS-D increased from exposure,and gained highest at one month after exposed,then gradually declined with time (Ps ＜ 0.05).Conclusion:It suggests that the levels of perceived stress,post-traumatic stress symptom,anxiety,depression may be the highest at one month after exposed.

Crystal structures of Bbp from Staphylococcus aureus reveal the ligand binding mechanism with Fibrinogen α

Bone sialoprotein-binding protein (Bbp), a MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family protein expressed on the surface of Staphylococcus aureus (S. aureus), mediates adherence to fibrinogen α (Fg α), a component in the extracellular matrix of the host cell and is important for infection and pathogenesis. In this study, we solved the crystal structures of apo-Bbp(273-598) and Bbp(273-598)-Fg α(561-575) complex at a resolution of 2.03 Å and 1.45 Å, respectively. Apo-Bbp(273-598) contained the ligand binding region N2 and N3 domains, both of which followed a DE variant IgG fold characterized by an additional D1 strand in N2 domain and D1' and D2' strands in N3 domain. The peptide mapped to the Fg α(561-575) bond to Bbp(273-598) on the open groove between the N2 and N3 domains. Strikingly, the disordered C-terminus in the apo-form reorganized into a highly-ordered loop and a β-strand G'' covering the ligand upon ligand binding. Bbp(Ala298-Gly301) in the N2 domain of the Bbp(273-598)-Fg α(561-575) complex, which is a loop in the apo-form, formed a short α-helix to interact tightly with the peptide. In addition, Bbp(Ser547-Gln561) in the N3 domain moved toward the binding groove to make contact directly with the peptide, while Bbp(Asp338-Gly355) and Bbp(Thr365-Tyr387) in N2 domain shifted their configurations to stabilize the reorganized C-terminus mainly through strong hydrogen bonds. Altogether, our results revealed the molecular basis for Bbp-ligand interaction and advanced our understanding of S. aureus infection process.

Detection of Virulence Genes of Staphyloccus aureus and Staphylococcus epidermidis Isolated from Suprapubic Urine from Infants with Fever

While methicillin-resistant Staphylococcus aureus (MRSA) isolated from urinary tract infection (UTI) has recently increased in elderly adult urology patients, it has been only rarely reported in infants. Therefore, in this study to understand whether MRSA may be involved in UTI of infants who run fever without other apparent causes, we identified and counted S. aureus and S. epidermidis in suprapubic urine from 750 febrile infants via microbiological methods, and confirmed the counts via multiplex PCR. And we also detected four virulence genes, mecA, PVL, bbp and icaA genes for S. aureus and S. epidermidis via multiplex PCR in the same specimens. S. aureus (28 cases) counts were as follows: >10(4) CFU/ml (3/28), 10(2)~10(3) CFU/ml (1/28) and 10(4) CFU/ml (2/26), 10(2)~10(3) CFU/ml (4/26) and 10(2)~10(3) CFU/ml (20/26). S. aureus virulence genes were detected in 26 cases as mecA (16/26, 59.3%), PVL (17/26, 63.0%), bbp (7/26, 26.9%) and icaA (20/26, 76.9%). S. epidermidis virulence genes were detected in 22 cases as mecA (17/22, 81.0%), PVL (15/22, 71.4%), bbp (3/22, 13.6%) and icaA (13/22, 50.1%). Therefore, mecA, PVL and icaA genes of MRSA and MRSE were detected with high positivity in urines from infants with fever. The results demonstrate that community-acquired MRSA or MRSE may be responsible for UTI incidence in febrile infants.

Evaluation of deproteinized bovine bone mineral as a bone graft substitute: A comparative analysis of basic characteristics of three commercially available bone substitutes / 대한치주과학회지

Bovine bone-derived bone substitutes are widely used for treatment of bone defects in dental and orthopedic regenerative surgery. The purpose of this study was to evaluate the basic characteristics of deproteinized bovine bone mineral as a bone graft substitute. Commercially available products from three different bovine bone minerals-Bio-Oss(Geistlich-Pharma, Switzerland), BBP(Oscotec, Korea), Osteograf/N-300(Dentsply Friadent Ceramed, USA) - were investigated. They were evaluated by scanning electron microscopy(SEM), energy dispersive X-ray spectrometer(EDS), surface area analysis(BET), and Kjeldahl protein analysis. Cell viability on different products was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) assay. The results of this study indicated that each bone substitute displayed distinct surface properties. Furthermore, Kjeldahl protein analysis indicated that residual crude proteins are present in deproteinized bovine bone mineral. BBP showed relatively large amount of residual protein, which indicated that the possibility of disease transmission can not be safely ruled out. Based on the results of this study, it is suggested that active quality management is strongly needed in operations that involve processing bovine bone tissue for medical use.

Periodontal Repair on Intrabony Defects treated with BBP(R) / 대한치주과학회지

The ultimate goal of periodontal disease therapy is to promote the regeneration of lost periodontal tissue, there have been many attempts to develop a method to achieve this goal, but none of them was completely successful. The purpose of this study was to compare the effects of treatment using BBP(R) with control treated by only modified Widman flap. 22 intrabony defects from 12 patients with chronic periodontitis were used for this study, 10 sites of them were treated with BBP(R) as experimental group and 12 site were treated by only modified Widman flap as control group. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded at 6 months later, and the significance of the changes was statistically analyzed. The results are as follows: 1. Probing depth of control(delta2.7+/-1.3mm) and experimental group(delta3.6+/-1.8mm) weres reduced with statistically significance(P<0.05), but this changes were not different between the two experiment, control group with statistically significance. 2. Gingival recession showed statistically significant increase in control group(delta2.1+/-1.2mm)(P<0.05), but not in experimental group(delta0.5+/-0.7mm), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 3. Bone probing depth showed statistically significant decrease in experimental group(delta2.9+/-1.0mm)(P<0.05), but not in control group(delta1.1+/-1.4mm), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 4. Loss of attachment showed statistically significant decrease in experimental group(delta3.1+/-1.7mm), but not in control group(delta0.6+/-1.2mm), and this changes were different between the two experiment, control group with statistically significance(P<0.05) On the basis of these results, treatment using BBP(R) improves the probing depth, bone probing depth and loss of attachment in intrabony defects.