Stress distribution of molars restored with minimal invasive and conventional technique: a 3-D finite element analysis

PURPOSE: This study aimed to analyze stress distribution and maximum von Mises stress generated in intracoronal restorations and in tooth structures of mandibular molars with various types of cavity designs and materials. MATERIALS AND METHODS: Threedimensional solid models of mandible molar such as O inlay cavity with composite and gold (OR-C, OG-C), MO inlay cavity with composite and gold (MR-C, MG-C), and minimal invasive cavity on occlusal and proximal surfaces (OR-M, MR-M) were designed. To simulate masticatory force, static axial load with total force of 200 N was applied on the tooth at 10 occlusal contact points. A finite element analysis was performed to predict stress distribution generated by occlusal loading. RESULTS: Restorations with minimal cavity design generated significantly lower values of von Mises stress (OR-M model: 26.8 MPa; MR-M model: 72.7 MPa) compared to those with conventional cavity design (341.9 MPa to 397.2 MPa). In tooth structure, magnitudes of maximum von Mises stresses were similar among models with conventional design (372.8 – 412.9 MPa) and models with minimal cavity design (361.1 – 384.4 MPa). CONCLUSION: Minimal invasive models generated smaller maximum von Mises stresses within restorations. Within the enamel, similar maximum von Mises stresses were observed for models with minimal cavity design and those with conventional design.

Safe Handling of Cytotoxic Drugs and Use of Personal Protective Equipment among Nurses at a Regional Cancer Center

PURPOSE: This purpose of this study was to identify the level of safe-handling of cytotoxic drugs and use of PPE (Personal Protective Equipment) among nurses at a regional cancer center in South Korea. METHODS: This was a cross-sectional descriptive study. The participants were 131 nurses who care for cancer patients undergoing chemotherapy. Demographic information, safe-handling of cytotoxic drugs and use of PPE were collected using questionnaires from May 7 to 25, 2018. RESULTS: Response rate was 98.4%. The mean age of the nurses was 28.2±4.4 years and their clinical nursing experience was 4.34±3.93 years. The mean scores out of 5 for the participants' safe handling of cytotoxic drugs was 3.73± 0.43. In use of PPE, the mean score of wearing gloves, masks, and gowns were 3.89±.77, 3.06±1.04, and 2.34±0.98, respectively. The main reason for not wearing PPE was ‘too busy’ (62.8%). The level of safe-handling of cytotoxic drugs was not significantly different according to any variables, but the use of PPE was significantly different according to age (p=.021). CONCLUSION: The findings showed that nurses had exposure to cytotoxic drugs in the processes of preparation, administration, cleaning of spills, and handling of patient waste. Education programs and continuous monitoring are needed to improve the use of PPE among nurses and trigger the appropriate motivation for consistent personal protection.

Antifactor Xa Levels in Critically Ill Korean Patients Receiving Enoxaparin for Thromboprophylaxis: A Prospective Observational Study

The aim of this study was to investigate antifactor Xa (aFXa) levels after once daily dose of 40 mg of enoxaparin and to evaluate factors influencing aFXa levels among Korean intensive care unit (ICU) patients. This prospective observational study was conducted between August and December 2011 in medical ICUs at Samsung Medical Center. AFXa levels between 0.1 and 0.3 U/mL were considered to be effective for antithrombotic activity. Fifty-five patients were included. The median aFXa levels were 0.22 (IQR 0.17-0.26) at 4 hr, 0.06 (IQR 0.02-0.1) at 12 hr, and 0 U/mL (IQR 0-0.03) at 24 hr. The numbers of patients showing effective antithrombotic aFXa levels were 48 (87.3%), 18 (32.7%), and 0 (0%) at 4, 12 and 24 hr, respectively. At 12 hr, higher sequential organ failure assessment (SOFA) scores and hyperbilirubinemia were significantly associated with low aFXa levels (OR, 0.58; 95% CI, 0.36-0.93; P = 0.02 and 0.06; 0.003-0.87; 0.04, respectively). Once daily dose of 40 mg of enoxaparin is inadequate for maintaining effective antithrombotic aFXa levels, and the inadequacy is more salient for patients with high SOFA scores and hyperbilirubinemia.

Analysis of in vitro apoptosis induced by virulent Korean isolate of classical swine fever virus in peripheral blood B cell line / 대한수의학회지

Classical swine fever (CSF) is a highly contagious disease among swine that has an important economic impact on worldwide. One clinical symptom of CSF is leukopenia, in particular lymphopenia, which is a characteristic event that occurs early in the course of CSF. Though lymphopenia associated with apoptosis, the pathogenic mechanism underlying the lymphopenia has not been well studied. To understand these mechanisms, we investigated the response of porcine B cell lines to infection with SW03, virulent strain isolated from swine tissue in Korea. This study demonstrated that SW03-infected L35 cell were induced apoptosis through the detection of activated caspase-3. In addition, SW03 infection leaded to alterations in pro-apoptotic, Bax, and anti-apoptotic, Bcl-xL proteins of Bcl-2 family. Our results would suggest that SW03-infected L35 cells induced apoptosis via intrinsic mitochondrial pathway.

Effect of Weissella cibaria on Fusobacterium nucleatum-induced Interleukin-6 and Interleukin-8 Production in KB Cells

Oral microorganisms, including pathogens together with commensals, interact with oral epithelial cells, which can lead to the activation and expression of a variety of inflammatory mediators in epithelial cells. Fusobacterium nucleatum is a filamentous human pathogen that is strongly associated with periodontal diseases. Our previous data suggest that Weissella cibaria, an oral commensal, inhibits the proliferation of periodontopathic bacteria including F. nucleatum. The aim of this study was to examine the effects of W. cibaria on the inflammatory mediators, interleukin (IL)-6 and IL-8, in KB cells stimulated by F. nucleatum. In a reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay, live F. nucleatum alone induced high levels of gene expression and protein release of IL-6 and IL-8, whereas W. cibaria alone did not induce IL-6 and IL-8 responses in KB cells. W. cibaria dose-dependently inhibited the increases of the IL-6 and IL-8 gene expression as well as IL-6 protein level in KB cells which was induced by F. nucleatum. Bacterial viability and its coaggregation with F. nucleatum are not essential in the inhibitory effect of W. cibaria. Visible effects of W. cibaria on the attachment and invasion of KB cells by F. nucleatum were observed. In conclusion, W. cibaria may exert immunomodulatory effects on the IL-6 and IL-8 responses to F. nucleatum-activated KB cells.

Activation of PPARalpha Attenuates IFNgamma and IL-1beta-induced Cell Proliferation in Astrocytes: Involvement of IL-6 Independent Pathway

The present study demonstrates the effect of fibrates, agonists of PPARalpha on cytokines-induced proliferation in primary cultured astrocytes. Alone or combination treatment with cytokines, such as IL-1beta (10 ng/ml), IFNgamma (10 ng/ml), and TNF-alpha (10 ng/ml) cause a significant increase of cell proliferation in a time-dependent manner. Treatment of astrocytes with bezafibrate and fenofibrate (0, 5, and 10 micrometer) reduced the IFNgamma and IL-1beta-induced cell proliferation in a dose-dependent manner. To address the involvement of IL-6 on the IFNgamma and IL-1beta-induced cell proliferation, released IL-6 level was measured. IFNgamma and IL-1beta cause an increase of released IL-6 protein level in a time-dependent manner. Furthermore, pretreatment with IL-6 antibody (0, 0.1, 1, 2.5, and 5 ng/ml) dose-dependently inhibited the IFNgamma and IL-1beta-induced cell proliferation. However, bezafibrate and fenofibrate did not affect increased mRNA and protein levels of IL-6 in IFNgamma and IL-1beta-stimulated astrocytes. Taken together, these results clearly suggest that activation of PPARalpha attenuates the IFNgamma and IL-1beta-induced cell proliferation through IL-6 independent pathway.

Neuroprotective Effect of Visnagin on Kainic Acid-induced Neuronal Cell Death in the Mice Hippocampus

Visnagin (4-methoxy-7-methyl-5H-furo[3,2-g][1]-benzopyran-5-one), which is an active principle extracted from the fruits of Ammi visnaga, has been used as a treatment for low blood-pressure and blocked blood vessel contraction by inhibition of calcium influx into blood cells. However, the neuroprotective effect of visnagin was not clearly known until now. Thus, we investigated whether visnagin has a neuroprotective effect against kainic acid (KA)-induced neuronal cell death. In the cresyl violet staining, pre-treatment or post-treatment visnagin (100 mg/kg, p.o. or i.p.) showed a neuroprotective effect on KA (0.1 microgram) toxicity. KA-induced gliosis and proinflammatory marker (IL-1beta, TNF-alpha, IL-6, and COX-2) inductions were also suppressed by visnagin administration. These results suggest that visnagin has a neuroprotective effect in terms of suppressing KA-induced pathogenesis in the brain, and that these neuroprotective effects are associated with its anti-inflammatory effects.

Severe Atherosclerotic Cerebral Steno-occlusion in Koreans: Factors Related to Intracranial versus Extracranial Involvement / 신경중재치료의학

PURPOSE: To evaluate the factors related to severe intracranical atherosclerotic stenosis (intracranial vs. extracranial) as diagnosed by conventional angiography in Korean patients. MATERIALS AND METHODS: We retrospectively analyzed the angiographic results and clinical data of 127 consecutive patients with an angiographically confirmed stenosis greater than 70%. Nine factors, i.e. age, gender, hypertension, diabetes mellitus, hyperlipidemia, smoking and alcohol habit, previous stroke and ischemic heart disease were included as presumed explanatory variables to discriminate different types of atherosclerotic stenosis (extracranial versus intracranial stenosis). Multiple logistic regression analysis was used to estimate independent effects of the predictive variables on cerebral occlusive disease. RESULTS: Among 127 patients, 62 patients had intracranial stenosis and 65 patients had extracranial stenosis. Compared to extracranial stenosis, mean age was lower (p < 0.001), female-to-male ratio was higher (p = 0.001) and the number of patients with diabetes mellitus was less (p = 0.019) in group of severe intracranial stenosis significantly. There were no differences in hypertension, smoke and alcohol, hyperlipidemia, ischemic heart disease and previous stroke between two groups. CONCLUSION: In Korean patients, severe atherosclerotic intracranial stenosis has younger, female and diabetes-free preference than severe atherosclerotic extracranial stenosis.

Subtraction CT Angiography with Motion Correction for Detection of Intra- and Extra-cranial Vascular Lesions: Technical Considerations and Initial Experience / 신경중재치료의학

PURPOSE: Clinical implementation of subtraction computed tomographic angiography (CTA) is limited due to motion artifact and/or long processing time. We evaluated the utility of a motion-corrected subtraction CTA technique for visualization of intra- and extra-cranial vascular lesions. MATERIALS AND METHODS: Pre- and post-contrast CT images were obtained in the target region of 53 consecutive patients which were consisted of 36 patients with 53 lesions and 17 normal patients. The source images were transferred to a personal computer (PC) and were automatically post-processed within one minute using novel motion-corrected subtraction CTA. The image quality of subtraction and non-subtraction CTAs was compared in each lesion category and lesion location using 3-point scale and Chi square test. RESULTS: The image quality of subtraction CTA was better than those from non-subtraction CTA (p<0.05) especially in the skull base lesions, such as carotid-cavernous fistulas, aneurysms in the cavernous internal carotid artery (ICA), and steno-occlusive lesions of the distal ICA, and extracranial lesions such as facial arteriovenous fistulas. CONCLUSION: The PC-based motion-corrected subtraction CTA technique allows fast generation of postprocessed images and can provide improved visualization of vascular anatomy and pathologies adjacent to bone in the skull base and head and neck areas.

Prevalence of Oral Microbes in the Saliva of Oncological Patients

This study examined the prevalence of oral microbes in the saliva of oncological patients and healthy subjects. PCR was used to assess the frequency of oral microbes including 3 cariogenic bacteria, 5 periodontopathic bacteria and 4 Candida species in the saliva of 104 oncological patients and 52 healthy subjects. Among these microorganims, Streptococcus mutans, Fusobacterium nucleatum and Candida albicans were most frequently detected in both groups. There were no significant differences in the prevalence of cariogenic bacteria between the patient and healthy groups, whereas significant differences in the frequency of Porphyromonas gingivalis and Tannerella forsythia were observed between the two groups (p < 0.05). The prevalence of all five periodontopathogens was higher in the healthy group than in the patient group. The prevalence of C. albicans in patients was significantly higher than that of healthy group (p < 0.05). In conclusion, there were significant differences in the prevalence of P. gingivalis, T. forsythia and C. albicans between the oncological patient group and healthy group.

Quantitative Analysis of Weissella cibaria against Periodontopathic Bacteria by Real-time PCR

The objective of this study was to analyze quantitatively whether Weissella cibaria could affect the proliferation of five periodontopathic bacteria, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum, after incubation for 8~48 h. In addition, by using real-time PCR with a dual-labeled probe, each growth of bacteria was examined under different growth media conditions. The proliferation of periodontopathic bacteria was significantly inhibited by W. cibaria after incubation for 24~48 h (p < 0.05), whereas the growth of W. cibaria was not affected by these pathogenic bacteria. The growth of P. gingivalis, T. forsythia and T. denticola significantly increased in each growth media after incubation for 24 h (p < 0.05), as compared to the culture in mixed growth media. However, no differences in the growth of five periodontopathic bacteria were observed between each growth media and mixed media after incubation for 48 h. The growth and pH of W. cibaria culture significantly were changed in MRS after incubation for 24~48 h (p < 0.05), as compared to the bacterial culture in mixed growth media. The pH of P. gingivalis and F. nucleatum culture significantly was changed in both growth media and mixed media after incubation for 24~48 h (p < 0.05). Our data indicate that W. cibaria significantly inhibits the proliferation of five periodontopathic bacteria and each growth of bacteria is quantitatively analyzed under various media conditions by real-time PCR.