Flexural Properties and Polished Surface Characteristics of a Structural Colored Resin Composite.

OBJECTIVE: The aim of this study was to determine the flexural properties and surface characteristics of a structural colored resin composite after different finishing and polishing methods, in comparison to those of conventional resin composites. METHODS AND MATERIALS: A structural color resin composite, Omnichroma (OM, Tokuyama Corp, Chiyoda City, Tokyo, Japan), and two comparison resin composites, Filtek Supreme Ultra (FS, 3M, St Paul, MN, USA) and Tetric EvoCeram (TE, Ivoclar Vivadent, Schaan, Liechtenstein), were used. The flexural properties of the resin composites were determined in accordance with the ISO 4049 specifications. For surface properties, 70 polymerized specimens of each resin composite were prepared and divided into seven groups of 10. Surface roughness (Sa), gloss (GU), and surface free energy (SFE) were investigated after the following finishing and polishing methods. Three groups of specimens were finished with a superfine-grit diamond bur (SFD), and three with a tungsten carbide bur (TCB). After finishing, one of the two remaining groups was polished with a one-step silicone point (CMP), and the other with an aluminum oxide flexible disk (SSD). A group ground with SiC 320-grit was set as a baseline. RESULTS: The average flexural strength ranged from 116.6 to 142.3 MPa in the following order with significant differences between each value: FS > TE > OM. The average E ranged from 6.8 to 13.2 GPa in the following order with significant differences between each value: FS > TE > OM. The average R ranged from 0.77 to 1.01 MJ/mm3 in the following order: OM > FS > TE. The Sa values of the OM groups polished with CMP and SSD were found to be significantly lower than those of the other resin composites, regardless of the finishing method. The GU values appeared to be dependent on the material and the finishing method used. The OM specimens polished with SSD showed significantly higher GU values than those polished with CMP. Most of the resin composites polished with SSD demonstrated significantly higher γS values compared to the other groups. Extremely strong negative correlations between Sa and GU in the combined data from the three resin composites and each resin composite and between Sa and γS in the OM specimens were observed; GU showed a strong positive correlation with γS in the same material. CONCLUSION: These findings indicate that both flexural and surface properties are material dependent. Furthermore, the different finishing and polishing methods used in this study were observed to affect the Sa, GU, and SFE of the resin composites.

Evaluation of Color-matching Ability of a Structural Colored Resin Composite.

PURPOSE: The present study evaluated the color-matching ability of a structural colored resin composite to compare it with resin composites employing pigments. METHODS AND MATERIALS: A structural colored resin composite (Omnichroma [OMC]), a supranano-filled resin composite (Estelite ∑ Quick [ELQ]), and a nano-filled resin composite (Filtek Supreme Ultra [FSU]) were used. Each resin composite was packed into a Teflon mold and pressed down with a clear strip under a glass slide. The specimens were light irradiated through the slide with a light-emitting diode curing unit. The thickness of the specimens (n=6) was measured with a digital caliper before being transferred to distilled water and stored at 37°C for 24 hours. The measurements of the optical characteristics of the specimens on a black-and-white background were performed using a spectrophotometer. D65 (CIE D65) was used as a light source for the spectrophotometer. Measurements were repeated three times for each specimen under each color-measurement condition, and average values for three same-shade specimens were calculated. One-way analysis of variance and Tukey post hoc tests were used (α=0.05). To determine its ability to match the color of artificial teeth, each shade of resin composite was placed in a cavity before performing color measurements. Using a spectrophotometer (CMS-35F S/C) with a flexible sensor, L*, a*, and b* values were obtained. RESULTS: The spectral reflectance curve of OMC showed that it reflected light wavelengths from 430-700 nm regardless of the background color and thickness of the specimens. The percentage of reflectance of ELQ decreased near wavelengths of 550-580 nm. Regarding the influence of background color on CIE L*, a*, b* values, the L* level showed significantly higher values for all tested materials with white backgrounds, and OMC was most affected by the difference in background color. However, a* values of ELQ and FSU were significantly higher with a black background than with a white background, and OMC showed a significantly higher value with a white background than with a black background. The b* values were higher with a white background than with a black background and were significantly higher for all three products, and these tendencies were much greater for ELQ and FSU. CONCLUSIONS: The ability of OMC to match the color of artificial teeth showed acceptable color compatibility, regardless of the shade of the artificial teeth and the depth of the cavity. However, ELQ and FSU showed reduced color compatibility, especially for a cavity depth of 3.0 mm. Excellent color matching ability was confirmed for the structural colored resin composite OMC, resulting in reduced color differences and therefore improving the esthetic appearance of the restoration, simplifying shade matching, and compensating for any color mismatch.

Total ankle arthroplasty incorporating a total talar prosthesis: a comparative study against the standard total ankle arthroplasty.

AIMS: Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA. PATIENTS AND METHODS: Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (61 to 82) and 75 years (62 to 82), respectively. The mean follow-up was 58 months (43 to 81) and 64 months (48 to 88), respectively. The outcome was assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Ankle Osteoarthritis Scale (AOS), and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). RESULTS: The mean preoperative JSSF score of the combined TAA and standard TAA groups was 44 (sd 11) and 49 (sd 10), respectively. The mean postoperative JSSF scores were 89 (sd 6.1) and 72 (sd 15), respectively. The mean postoperative JSSF score of the combined TAA group was significantly higher (p = 0.0034). The mean preoperative AOS scores for pain and function in the combined TAA and standard TAA groups were 5.8 (sd 3.3) and 5.5 (sd 3.1), and 8.6 (sd 1.3), and 7.1 (sd 2.9), respectively. The mean postoperative AOS scores of pain and function were 2.5 (sd 2.5) and 2.2 (sd 1.9), and 2.5 (sd 3.3) and 3.4 (sd 2.9), respectively. There were no significant differences between the two groups in terms of postoperative AOS scores. The mean postoperative SAFE-Q scores were: for pain, 76 (sd 23) and 70 (sd 23); for physical function, 66 (sd 25) and 55 (sd 27); for social function, 73 (sd 35) and 62 (sd 34); for shoe-related, 73 (sd 19) and 65 (sd 26); and for general health, 78 (sd 28) and 67 (sd 29), respectively. There were no significant differences between the two groups in terms of postoperative SAFE-Q scores. CONCLUSION: Combined TAA resulted in better clinical results than standard TAA. Cite this article: Bone Joint J 2019;101-B:443-446.

Application of the Self- Assembling Peptide P11-4 for Prevention of Acidic Erosion.

The aim of this study was to use ultrasonography to evaluate the effect of the self-assembling peptide P11-4 on acid erosion prevention. Curodont Repair (CR), which includes peptide P11-4, was used. Rectangular prisms of bovine enamel (4×1×1 mm) were immersed in pure orange juice for a period of 5 minutes six times per day for 28 days. These samples were divided into four groups of six specimens each and treated differently for an additional period of 28 days: 1) baseline group specimens were stored in artificial saliva; 2) CR group specimens were exposed to curodont without acid challenge; 3) NCRA (no curodont+acid challenge) specimens were treated with orange juice without curodont exposure; and 4) CRA (CR+acid challenge) specimens were treated with curodont before treatment with orange juice. The propagation time of longitudinal ultrasonic velocity (UV) was measured. Ultrastructural observation of each tested enamel surface was carried out using field-emission scanning electron microscopy (SEM). The UV data were analyzed using two-way analysis of variance with time and treatment as confounding factors. Post hoc pairwise tests among groups were performed using the Tukey honestly significant difference test. The average UV in intact bovine enamel for the baseline group ranged from 4,483 to 4,549 m/s and did not vary significantly within the test period. The average ultrasonic velocity (UV) in all samples decreased after the initial erosion. The UV in NCRA decreased further over time. Increased UVs were found for CR and CRA. For CR and CRA, there was no significant difference in UV at the end of the experiment from the initial value before erosion. In the results of SEM observation, the CR and CRA groups had similar morphologic features in that etching patterns were not clearly due to precipitation between the enamel rods. From the results of this in vitro study, it might be concluded that applying enamel matrix derivatives and self-assembling peptides on erosive lesions can improve remineralization.

Continuous-wave and mode-locked lasers on the base of partially disordered crystalline Yb3+:{YGd2}[Sc2](Al2Ga)O12 ceramics.

We present cw and mode-locked laser operations on the base of partially disordered crystalline Yb(3+):{YGd(2)}[Sc(2)](Al(2)Ga)O(12) ceramics. In continuous-wave laser operations, the average power of 2.9 W at the wavelength of 1051 nm and 2.8 W at the wavelength of 1031 nm with above 40% optical-to-optical efficiencies were achieved. In mode-locked laser operation, pulses as short as 69 fs with the average power of 820 mW was also obtained.

Ultrasonic determination of the effect of casein phosphopeptide-amorphous calcium phosphate paste on the demineralization of bovine dentin.

The purpose of this study was to investigate the demineralization of dentin by measuring changes in the velocity of the sonic longitudinal waves transmitted through this substrate. One group of samples was immersed in demineralization solution for 10 min twice a day and then stored in artificial saliva. Two additional groups of samples were treated with a solution of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste or a placebo paste without CPP-ACP before demineralization and a control group was stored in artificial saliva. The sonic velocity of the demineralized specimens was found to decrease significantly over time. No significant increase in sonic velocity was observed in specimens treated with CPP-ACP, suggesting that CPP-ACP acted to prevent demineralization.

Correlation between the incidence of central nodal necrosis in cervical lymph node metastasis and the extent of differentiation in oral squamous cell carcinoma.

OBJECTIVES: To investigate the incidence of central nodal necrosis (CNN) in the cervical lymph nodes of patients with oral squamous cell carcinoma (SCC) and the factors that influence the formation of CNN. METHODS: Lymph nodes shown as CNN on computed tomography (CT) films in 107 lymph nodes from 27 patients with oral SCC were selected. Lymph nodes with CNN on CT films were compared with the pathological findings of lymph nodes on specimens. We compared many kinds of factors influencing the formation of CNN, including the differentiated type, with the incidence of CNN. RESULTS: Significant relationships were found between the incidence of CNN in metastatic lymph nodes and the presence of well-differentiated SCC and the presence of keratinization in tumour cells. CONCLUSIONS: The results indicated that if a patient had SCC with low-grade differentiation, CNN in small lymph nodes would be difficult to detect on CT scan. Therefore, noting changes in lymph node density in the absence of CNN on CT scans is necessary in case the primary tumour is low-grade SCC.

The high prognostic value of the histologic grade at the deep invasive front of tongue squamous cell carcinoma.

BACKGROUND: Although many histopathologic factors in squamous cell carcinoma of the tongue predict the prognosis, the major predictive factors have not been identified clearly. This study analyzed the prognostic value of the histologic grade at the deep invasive front of tongue squamous cell carcinoma. METHODS: The clinicopathologic features of 124 consecutive patients seen between January 1985 and December 1999 with previously untreated squamous cell carcinoma of the tongue were reviewed. Their mean age was 58.5 years (range: 23-90) and the male-female ratio was 1.8: 1 (79 men and 45 women). There were 41, 40, 30, and 13 cases at stage I to stage IV, respectively. The clinicopathologic factors, especially the histologic grade at the deep invasive front (invasive front grade, IFG), were analyzed to determine factors predicting prognosis. RESULTS: The 5-year disease-free survival rate of the patients treated with curative aim only was 66.7%. Clinicopathologic factors significantly associated with the prognosis were T classification, tumor size, stage classification, tumor depth, macroscopic appearance, cervical lymph node metastasis (nodal metastasis), microvascular invasion, and IFG. In a multivariate analysis, patients with tumor depth >/=4 mm, IFG >/=8 points, and nodal metastasis had a reduced disease-free survival and IFG >/=11 points had a predictive value for nodal metastasis (odds ratio: 7.34; P = 0.0019). CONCLUSION: This study found that a high IFG malignancy score had a high prognostic value for squamous cell carcinoma of the tongue.

Optic nerve compression by normal carotid artery in patients with normal tension glaucoma.

AIM: To determine whether compression of the optic nerve by the intracranial carotid artery (ICA) can be a causative factor of normal tension glaucoma (NTG). METHODS: The medical records of 103 eyes of 54 Japanese patients with NTG and 104 eyes of 52 age matched control patients were reviewed. The neuroradiological findings of magnetic resonance images (MRI) were evaluated to determine the relation between the optic nerve and ICA. The clinical characteristics and general medical conditions, such as diabetes and systemic hypertension, were also compared between the two groups. RESULTS: The prevalence of optic nerve compression by the ICA in patients with NTG was 49.5%, which was significantly higher than that in control group with 34.6% (p = 0.035). Bilateral compression of the optic nerve was detected in 22 patients with NTG (40.7%), and this was also significantly higher (p = 0.029) than that in the control group (11 patients, 21.2%). In the NTG group, eyes with cup/disc ratio (C/D ratio) > or =0.7 showed a higher percentage of compression (52.6%) compared with eyes with C/D ratio of <0.7 (12.5%; p = 0. 042). The presence of diabetes and hypertension did not affect the incidence of optic nerve compression by ICA significantly. CONCLUSIONS: The significantly higher percentage of NTG patients who had optic nerve compression by the ICA suggests that compression of the optic nerve by ICA may be a possible causative factor or a risk factor for optic nerve damage in some patients with NTG.

Traumatic neuroma in the lower lip arising following laser/cryosurgery to treat a mucocele.

A 15-year-old girl presented with a painless recurrent swelling on her right lower lip mucosa for about 10 months. She had a past history of treatment with laser surgery and cryosurgery. The clinical diagnosis was a 'recurrent mucocele'. Histopathological examination of the surgical specimen revealed a mucocele close to a neuroma with irregular nerve fascicles, leading to a diagnosis 'mucocele accompanied with a traumatic neuroma'. In the present report, the traumatic neuroma appears to have arisen following laser or cryosurgery.

Transfusion transmitted virus (TTV) in dental patients.

Transfusion transmitted virus (TTV) is a new DNA virus found in patients with post-transfusion hepatitis. The prevalence of this virus among dental patients has not been reported, therefore, the prevalence of TTV infection in consecutive dental inpatients was evaluated. TTV DNA was assayed by the polymerase chain reaction (PCR) in 441 dental inpatients with oral cancer (n=192) or oral cysts (n=249). The serum HBs antigen and HCV antibody as well as aspartate transaminase (AST), alanine transaminase (ALT), and gamma glutamyl transpeptidase (gamma-GTP) concentrations were also measured. Of 441 subjects, 137 were infected with TTV (31.1%). This prevalence of TTV was much higher than that of HBV or HCV (HBV 1.2%; HCV 6.0%) in these dental patients. There was no gender or age difference in the prevalence of TTV infection. Of the 192 patients with oral cancer, 57 subjects had TTV in their sera, while 80 of 249 with oral cystic disease had TTV. The prevalence of TTV was similar between the two different disease groups. Neither the serum ALT nor serum AST concentrations were different between the subjects positive and negative for TTV DNA. In hospitalized dental patients, 31.1% were infected with TTV. The prevalence of TTV was much higher than that of HBV or HCV. There was no difference in the prevalence of TTV between subjects with cancer and cysts. Dentists should maintain high standards of infection control when treating any dental patient.

Fibroma of the vulva.

We describe a patient with fibroma of the vulva. The tumor had areas of marked hypointensity consistent with fibrosis on T1 and T2 weighted magnetic resonance (MR) images. The presence of abundant fibrous tissues on MR images enabled us to make a preoperative diagnosis of fibroma.

Solid-state microstructures, thermal properties, and crystallization of biodegradable poly(butylene succinate) (PBS) and its copolyesters.

Studies of solid-state structures under different crystallization conditions, melting behavior, and crystal growth kinetics are reported for biodegradable aliphatic poly(butylene succinate) (PBS) and its random copolyesters of poly(butylene succinate-co-14 mol %ethylene succinate) [P(BS-co-14 mol %ES)] and poly(butylene succinate-co-15 mol %hexamethylene succinate) [P(BS-co-15 mol %HS)]. The crystal structures of two copolyesters determined by wide-angle X-ray diffraction (WAXD) are the same as that of the PBS homopolymer, suggesting that the second comonomers ES or HS units are excluded from the crystalline core and are in an amorphous state. The further investigations on the crystalline and amorphous phase structures and sizes by small-angle X-ray scattering (SAXS) method have provided quantitative evidence that the existence of second comonomers increases the amorphous thickness of copolyesters but that the influences of comonomers on the lamellar crystal structure and size of copolyesters are complicated. The origin of the complexity and its influences on the equilibrium melting temperature T(m)(0) of copolyester are discussed in the present paper. Gibbs-Thomson and Hoffman-Weeks equations were applied for the determination of T(m)(0) of PBS, P(BS-co-14 mol %ES), and P(BS-co-15 mol %HS)-three samples. Two equations gave different T(m)(0) values for each sample. On the basis of the Gibbs-Thomson equation, the P(BS-co-15 mol %HS) copolyester has the same T(m)(0) value as that of the PBS homopolymer, while the P(BS-co-14 mol %ES) copolyester has a lower one. This is due to the different influences of the second comonomers on the crystalline phase structure indicated by SAXS results, and the Gibbs-Thomson equation has been suggested to be more reliable. The crystal growth kinetics of the three samples was analyzed by using the secondary nucleation theory, and the influences of various parameters on the regime transition and nucleation constant were studied. Meanwhile some interrelations between regime transition temperature and melting behavior were found for the three samples.

Mechanism of the radiosensitization induced by vinorelbine in human non-small cell lung cancer cells.

Vinorelbine (Navelbine, KW-2307), a semisynthetic vinca alkaloid, is a potent inhibitor of mitotic microtubule polymerization. The aims of this study were to demonstrate radiosensitization produced by vinorelbine in human non-small cell lung cancer (NSCLC) PC-9 cells and to elucidate the cellular mechanism of radiosensitization. A clonogenic assay demonstrated that PC-9 cells were sensitized to radiation by vinorelbine with a maximal sensitizer enhancement ratio at a 10% cell survival level of 1.35 after 24-h exposure to vinorelbine at 20 nM. After 24-h exposure to vinorelbine at 20 nM, the approximately 67% of the cells that had accumulated in the G2/M-phase were cultured in the absence of vinorelbine and then irradiated at a dose of 8 Gy. Flow cytometric analyses showed prolonged G2/M accumulation concomitant with continuous polyploidization, and induction of apoptosis was observed in the cells subjected to the combination of vinorelbine-pretreatment and radiation. Polyploidization and induction of apoptosis were confirmed by morphological examination and a DNA fragmentation assay, respectively. We concluded that vinorelbine at a minimally toxic concentration moderately sensitizes human NSCLC cells to radiation by causing accumulation of cells in the G2/M-phase of the cell cycle. Prolonged G2/M accumulation concomitant with continuous polyploidization and increased susceptibility to induction of apoptosis may be associated with the cellular mechanism of radiosensitization produced by vinorelbine.

Risk stratification using serum concentrations of cardiac troponin T in patients with end-stage renal disease on chronic maintenance dialysis.

BACKGROUND: It has been recently suggested that cardiac troponin T (cTnT) may be more sensitive than troponin I (cTnI) for subclinical myocardial cell injury in patients on chronic dialysis. METHODS: We prospectively compared the predictive value of cTnT with cTnI, atrial (ANP) and brain natriuretic peptide (BNP) in 100 consecutive outpatients on chronic dialysis without acute coronary syndromes over a period of 3 months, and assessed whether the combination of cTnT with clinical information including age, duration of dialysis, and medical histories was useful for risk stratification of these patients. During the 2-year follow-up period, 19 patients died, mostly due to cardiac causes (53%). RESULTS: The area under the receiver operator characteristic (ROC) curve for the cTnT as predictor of both overall and cardiac death was significantly greater than the area under the cTnI curve (p < 0.0001 and p = 0.01), the BNP curve (p < 0.001 and p < 0.01) or the ANP curve (p < 0.0001 and p < 0.005). In a stepwise multivariate Cox regression analysis, only cTnT (p < 0.05 and p < 0.01) and a history of heart failure requiring hospitalization (p < 0.05 and p < 0.005) were independent predictors of both all cause and cardiac mortality. Using parameters of cTnT > or =0.1 microg/l and/or history of heart failure, the overall and cardiac mortality rate for the low risk group (n=66) were 4.5% and 1.5%, respectively, 40% and 16% for the intermediate risk group (n=25), and 67% and 56% for the high risk group (n=9). CONCLUSION: cTnT concentrations offer a higher prognostic accuracy than cTnI, ANP and BNP in patients on chronic dialysis. The combination of elevated cTnT and a history of heart failure may be a highly effective means of risk stratification of these patients.

Lack of association between QT dispersion and blood pressure response during dental surgery.

1. It is well known that dental surgery induces increases in blood pressure. However, the factors influencing this increase are not yet fully understood. We have determined the relationship between QTc (= QT/RR(1/2), with RR being the R-R interval in seconds) dispersion, measured with a 12-lead surface electrocardiogram, and changes in blood pressure during tooth extraction. 2. Both QTc dispersion and the power spectrum of R-R variability were determined before the dental surgery was undertaken. The low-frequency (LF; 0.041-0.140 Hz), high- frequency (HF; 0.140-0.500 Hz) and total spectral powers (TF; 0.000-4.000 Hz) were calculated and the ratio of LF to HF and the percentage of HF relative to TF (%HF; HF/TF x 100) were used as indices of sympathovagal balance and parasympathetic activities, respectively. 3. In the present study, QTc dispersion failed to correlate with LF/HF and %HF. Systolic blood pressure and pulse rate increased significantly during tooth extraction; however, changes in these variables failed to correlate with QTc dispersion. 4. These results suggest that QTc dispersion is not associated with the power spectrum of R-R variability and that it does not affect the blood pressure response during tooth extraction.

Target-induced conformational adaptation of calmodulin revealed by the crystal structure of a complex with nematode Ca(2+)/calmodulin-dependent kinase kinase peptide.

Calmodulin (CaM) is a ubiquitous calcium (Ca(2+)) sensor which binds and regulates protein serine/threonine kinases along with many other proteins in a Ca(2+)-dependent manner. For this multi-functionality, conformational plasticity is essential; however, the nature and magnitude of CaM's plasticity still remains largely undetermined. Here, we present the 1.8 A resolution crystal structure of Ca(2+)/CaM, complexed with the 27-residue synthetic peptide corresponding to the CaM-binding domain of the nematode Caenorhabditis elegans Ca(2+)/CaM-dependent kinase kinase (CaMKK). The peptide bound in this crystal structure is a homologue of the previously NMR-derived complex with rat CaMKK, but benefits from improved structural resolution. Careful comparison of the present structure to previous crystal structures of CaM complexed with unrelated peptides derived from myosin light chain kinase and CaM kinase II, allow a quantitative analysis of the differences in the relative orientation of the N and C-terminal domains of CaM, defined as a screw axis rotation angle ranging from 156 degrees to 196 degrees. The principal differences in CaM interaction with various peptides are associated with the N-terminal domain of CaM. Unlike the C-terminal domain, which remains unchanged internally, the N-terminal domain of CaM displays significant differences in the EF-hand helix orientation between this and other CaM structures. Three hydrogen bonds between CaM and the peptide (E87-R336, E87-T339 and K75-T339) along with two salt bridges (E11-R349 and E114-K334) are the most probable determinants for the binding direction of the CaMKK peptide to CaM.

Multiple myeloma: short T2 on MR imaging.

We describe a rare case of multiple myeloma with marked hypointense areas on both T1- and T2-weighted images. Amyloid deposition and calcification were not found histologically. Hypointensity on T2-weighted images may be caused by distributed free radicals produced by significant macrophages.

Cardiovascular and sympathetic responses to dental surgery with local anesthesia.

We investigated changes in blood pressure and blood variables, including plasma catecholamines, serum glucose and insulin concentrations, during dental surgery. The study included 11 normotensive patients (age, 22.5+/-0.7 years) who underwent tooth extraction at Kyushu Dental College Hospital. Three to 7 days prior to dental surgery, blood pressure, pulse rate, and heart rate variability were measured every 30 min over 24 h. The low frequency (LF: 0.05 to 0.15 Hz) and high frequency (HF: 0.15 to 0.40 Hz) powers were calculated, and the ratio of LF to HF (LF/HF) and HF were used as indexes of sympathetic and parasympathetic activities, respectively. Lidocaine, 2% with epinephrine (1:80,000), was used as the local anesthetic for all patients. Systolic blood pressures significantly increased during dental surgery (+10.8+/-3.5 mmHg); however, this increase failed to correlate not only with baseline systolic blood pressure but with 24-h averaged blood pressures, LF/HF or HF. On the other hand, plasma epinephrine and norepinephrine concentrations increased during dental surgery, and peak values of these variables were obtained after local anesthesia and during tooth extraction, respectively. Serum glucose level increased after local anesthesia (control vs. local anesthesia: 5.16+/-0.11 vs. 5.62+/-0.10 mmol/l; p<0.01); however, plasma insulin concentrations did not change significantly. These results suggest that 1) ambulatory measurements of blood pressure and heart rate variability over 24 h cannot predict the responses of blood pressure during dental surgery, and that 2) administration of local anesthetic and tooth extraction activate sympathoadrenal outflow, resulting in an increase in serum glucose level in normotensive subjects.

Direct screening of the IMP-1 metallo-beta-lactamase gene (blaIMP) from urine samples by polymerase chain reaction.

BACKGROUND: As Gram-negative bacterial isolates producing plasmid-mediated IMP-1 metallo-beta-lactamase usually demonstrate resistance to various broad-spectrum beta-lactams, including cephamycins and carbapenems, transmission and proliferation of these microorganisms in clinical settings could become a clinical threat in the near future. According to previous studies by the same authors, IMP-1-producing strains are usually isolated from urine samples. Therefore, in this study, a polymerase chain reaction (PCR) was applied for direct screening of the IMP-1 metallo-beta-lactamase gene in urine samples. METHOD: Urine samples were collected from 273 inpatients to whom various broad-spectrum beta-lactams, including carbapenems, had been administered in 57 hospitals in 1997. DNA templates for PCR analyses were prepared directly from 19 urine samples from which Serratia marcescens strains demonstrating high-level resistance (minimal inhibitory concentration > 128 microg/mL) to both ceftazidime and cefoperazone-sulbactam were later isolated. RESULTS: The IMP-1 metallo-beta-lactamase gene (blaIMP)-specific 578 bp fragments were able to be amplified successfully in eight of the 19 samples. In the seven strains isolated from the eight samples, the presence of blaIMP was also detected by a DNA hybridization analysis. The lower limit of the PCR method was determined as 1 x 10(2) CFU of blaIMP-bearing bacterial cells per 1 mL of urine sample. No false positive result was found. CONCLUSION: The PCR-aided direct screening of blaIMP is applicable to early recognition of IMP-1-producing bacteria in urine samples. This method would help to prevent nosocomial and interhospital transmission of this kind of hazardous bacteria, as well as the advancement of rigorous infection control.