Needs regarding care and factors associated with unmet needs in disease-free survivors of surgically treated lung cancer

BACKGROUND

To evaluate the long-term needs of lung cancer survivors and to explore factors associated with unmet need.

PATIENTS AND METHODS

We recruited lung patients treated with curative surgery from 2001 through 2006 at two centers in Korea. Needs in the domains of information, supportive care, education and counseling, and socioeconomic support were measured. We selected the four most frequently reported items of unmet need among 19 items in four domains.

RESULTS

The most frequently reported unmet needs were Complementary and alternative medicine (CAM) and folk remedies (59.8%) in the Information domain, Counseling and treatment of depression and anxiety (63.5%) in the Supportive care domain, diet, exercise and weight control (55.1%) in the Education and counseling domain and Financial support (90.4%) in the socioeconomic support domain. Unmet needs for psychological treatment was significantly greater in participants who were employed (adjusted odds ratio [aOR], 2.25; 95% confidential interval [CI], 1.12 to 4.53). Unmet needs for diet, exercise and weight control were significantly greater in participants who had not received chemotherapy (aOR, 1.76; 95% CI, 1.09 to 2.85). Unmet need for financial support was greater in participants who were married (aOR, 4.14, 95%CI, 1.12 to 15.22) and those who had not received chemotherapy (aOR, 5.91, 95%CI, 1.91 to 18.31).

CONCLUSION

There were substantial unmet needs for information regarding psychological support, education for diet and exercise, and financial support among lung cancer survivors.

A direct comparison of expression profiles of adhesion molecules on naïve T cells between cord blood and steady-state bone marrow grafts of healthy donors

INTRODUCTION

We compared the profiles of adhesion molecule expression on naïve T cells between umbilical cord blood (UCB) and steady-state bone marrow (SS-BM) grafts.

METHODS

The expressions of 4 adhesion molecules, including very late antigen 4 (VLA-4), intercellular adhesion molecule-1 (ICAM-1), L-selectin, and lymophocyte function-associated antigen-1 (LFA-1) on naïve T cells in UCB (n = 25) and SS-BM (n = 10) were analyzed using flow cytometry.

RESULTS

The expressions of ICAM-1 and L-selectin on CD4(+) T cells and CD8(+) T cells in UCB were significantly lower than those on SS-BM (P < .05 for all). The expressions of VLA-4 and LFA-1 on CD8(+) T cells in UCB were significantly lower than those of SS-BM (P = .002 and .047, respectively). Compared with SS-BM, we observed lower expression of ICAM-1 on naïve CD4(+) and CD8(+) T cells in UCB (P < .001 for all). The percentages of interferon (IFN)-γ positive cells among naïve CD4(+) and CD8(+) T-cell subsets were significantly lower in UCB, leading to ready polarization of naïve UCB T cells from a Th1 to Th2 phenotype versus those on SS-BM.

CONCLUSIONS

Our results among UCB suggested lower intensities of ICAM-1 expression on naïve T cells and their easier polarization from Th1 to Th2 elements.

Epidemiology of pediatric critically-ill patients presenting to the pediatric emergency department

This study aimed to analyze the epidemiologic patterns of pediatric critically-ill patients presenting to the emergency department (ED) and the etiologies of intensive care unit (ICU) admission of different age groups.This retrospective study of all children aged less than 18 years presenting with critical illnesses to the ED was conducted in a tertiary medical center in Taiwan from 2003 to 2007. All patients transferred to the ICU from the ED were included without distinction. Demographic data of critically-ill children admitted to the ED and ICU were analyzed. Etiologies of the ICU admissions were analyzed by various age groups.There were 2978 critically-ill children admitted to the ICU from the ED. In 120 pediatric patients with out-of-hospital cardiac arrest, cases with pulseless electrical activity or ventricular fibrillation had higher successful CPR rates than patients with asystole (both p<0.05). In patients admitted to ICUs, complications from the perinatal period, respiratory system diseases, accidental injuries and poisoning were the predominant etiologies respectively in young children (42.5%), school-aged children (38.5%), and adolescents (47.9%). Moreover, the most common of which was respiratory distress syndrome in neonates followed by bacterial pneumonia and status epilepticus.Epidemiologic analysis may provide primary clinicians to identify significant differences in admission rates based on different etiologies of various age groups.

Characteristic dermoscopic features of primary cutaneous amyloidosis: a study of 35 cases

BACKGROUND

Primary cutaneous amyloidosis (PCA) is a relatively common skin disorder among Asians and South Americans. It is usually diagnosed clinically. However, for cases with atypical presentations, the diagnosis can be a challenge and skin biopsy may be necessary. Dermoscopy has been proved to be a valuable, noninvasive tool in the diagnosis of cutaneous pigmented diseases. Most lesions of PCA show hyperpigmentation and the major histopathological abnormalities of PCA occur in the epidermis and dermal papillae. Dermoscopy might be a powerful tool to provide valuable information for the diagnosis of PCA.

OBJECTIVES

We aimed to find characteristic dermoscopic features of PCA.

MATERIALS AND METHODS

Cases with typical clinical presentations of PCA, either macular or lichen subtypes, were included in this study. All were evaluated using a hand-held, polarized and nonpolarized dermoscope.

RESULTS

A total of 35 patients with clinically diagnosed PCA were enrolled. Eighteen patients had lesions consistent with macular amyloidosis and 17 with lichen amyloidosus. We found two major dermoscopic patterns characteristic of PCA. The most common dermoscopic finding of PCA was a central hub, which could be either white or brown, surrounded by various configurations of pigmentation. For cases of lichen amyloidosus with prominent hyperkeratosis, the central hub was replaced by a scar-like morphology.

CONCLUSIONS

This is the first study to report the characteristic dermoscopic features of PCA. We demonstrate that the use of a dermoscope may assist in achieving an accurate diagnosis of PCA.

Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy

Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro- and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two-dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.

The effects of fatigue on the torque-frequency curve of the human paralysed soleus muscle

An advanced understanding of the torque-generating properties of the chronically paralysed soleus muscle may be instrumental in developing improved methods to activate human paralysed muscle. We established the shape of the torque-frequency curve before and after fatigue of the human paralysed soleus muscle. After fatigue, the normalized torque-frequency curve was shifted to the right, suggesting a higher frequency was required to generate the same relative torque. Low frequency fatigue (LFF) consisting of reduced torques at low frequencies and normal torques at higher frequencies was demonstrated. Conversely, the acutely paralysed soleus muscle was found to be fatigue-resistant and showed no shift in the torque-frequency curve. The muscle activation history (potentiation), LFF, and changing contractile speeds may affect the torque-frequency curve after fatigue. These factors may also play an important role in the development of optimal methods to activate paralysed muscle to attenuate fatigue.

Giant ambipolar Rashba effect in the semiconductor BiTeI

We observe a giant spin-orbit splitting in the bulk and surface states of the noncentrosymmetric semiconductor BiTeI. We show that the Fermi level can be placed in the valence or in the conduction band by controlling the surface termination. In both cases, it intersects spin-polarized bands, in the corresponding surface depletion and accumulation layers. The momentum splitting of these bands is not affected by adsorbate-induced changes in the surface potential. These findings demonstrate that two properties crucial for enabling semiconductor-based spin electronics-a large, robust spin splitting and ambipolar conduction-are present in this material.

Complete genome sequence of Thauera aminoaromatica strain MZ1T

Thauera aminoaromatica strain MZ1T, an isolate belonging to genus Thauera, of the family Rhodocyclaceae and the class the Betaproteobacteria, has been characterized for its ability to produce abundant exopolysaccharide and degrade various aromatic compounds with nitrate as an electron acceptor. These properties, if fully understood at the genome-sequence level, can aid in environmental processing of organic matter in anaerobic cycles by short-circuiting a central anaerobic metabolite, acetate, from microbiological conversion to methane, a critical greenhouse gas. Strain MZ1T is the first strain from the genus Thauera with a completely sequenced genome. The 4,496,212 bp chromosome and 78,374 bp plasmid contain 4,071 protein-coding and 71 RNA genes, and were sequenced as part of the DOE Community Sequencing Program CSP_776774.

Hepatitis C among methadone maintenance treatment patients in Shanghai and Kunming, China

BACKGROUND

This study aims to: (1) document the prevalence of hepatitis C virus (HCV) among methadone maintenance treatment (MMT) patients in Kunming and Shanghai; (2) examine risk factors for HCV by comparing those who tested positive with those who were negative and (3) examine if HCV serostatus is related to attitudes toward MMT.

METHODS

Using data collected from 306 patients admitted to MMT in 2009-2010 in Shanghai and Kunming, we compared HCV-positive and HCV-negative patients (based on clinical records) on their HCV knowledge and risk behaviors and attitudes toward MMT.

RESULTS

The HCV seropositive rate was 53.3% (51.3% in Shanghai and 55.5% in Kunming) and a majority of patients did not know their serostatus. Patients scored on average fewer than 6 correct out of the 20 items in the HCV knowledge questionnaire. Recent injection use and length of opiate use were strong predictors of HCV status, while no differences were found between HCV-positive and HCV-negative individuals in sexual risks or HCV knowledge. Both groups expressed similar views toward MMT.

CONCLUSION

The high HCV prevalence and the general lack of knowledge about HCV infection, transmission and treatment suggest the need to provide HCV education and health promotion programs among patients in MMT.

Formation of Ge quantum dots array in layer-cake technique for advanced photovoltaics

We report a simple and manageable growth method for placing dense three-dimensional Ge quantum dot (QD) arrays in a uniform or a graded size distribution, based on thermally oxidizing stacked poly-SiGe in a layer-cake technique. The QD size and spatial density in each stack can be modulated by conditions of the Ge content in poly-Si(1-x)Ge(x), oxidation, and the underlay buffer layer. Size-dependent internal structure, strain, and photoluminescence properties of Ge QDs are systematically investigated. Optimization of the processing conditions could be carried out for producing dense Ge QD arrays to maximize photovoltaic efficiency.

Change in cerebral perfusion after carotid angioplasty with stenting is related to cerebral vasoreactivity: a study using dynamic susceptibility-weighted contrast-enhanced MR imaging and functional MR imaging with a breath-holding paradigm

BACKGROUND AND PURPOSE

Carotid angioplasty with stent placement (CAS) is an optional treatment for significant carotid stenosis. Cerebral vasoreactivity (CVR), representing the reserve capacity of cerebral perfusion, usually decreases in patients with severe carotid stenosis. This study aimed to investigate the relationship between the baseline CVR assessed by functional MR imaging (fMRI) and the changes in cerebral blood flow (CBF) after CAS.

MATERIALS AND METHODS

Fourteen patients with at least 70% unilateral carotid stenosis underwent CAS. Baseline CVR was evaluated by fMRI a under breath-holding paradigm. CBF was assessed by dynamic susceptibility-weighted contrast-enhanced MR imaging before and 3-5 days after CAS. The lateral index (LI) was defined as (n - L) / (n + L), where n and L represent the number of activated voxels in fMRI on the normal and lesion hemispheres, respectively.

RESULTS

No subject had clinical evidence of hyperperfusion syndrome. The LI represented baseline CVR. Patients were divided into normal (LI < 0, n = 6) and impaired (LI > 0, n = 8) CVR groups. The CBF on the normal and lesion sides was calculated separately. CBF increment on the lesion side after CAS was significantly higher in the impaired CVR group than that in the normal CVR group (P = .035). There was a significantly positive correlation between CVR impairment and the CBF increment (P = .026).

CONCLUSIONS

fMRI could be a reproducible tool in evaluating CVR. After CAS, early CBF changes on the lesion side are more prominent in patients with impaired CVR. Baseline CVR might predict early CBF increase after CAS.

Sero-epidemiology of hepatitis A virus infection among healthcare workers in Korean hospitals

Hepatitis A virus (HAV) has been increasingly reported in Korea as has an outbreak in Korean healthcare workers (HCWs). This 2008 study evaluated the sero-epidemiology of HAV infections among 3696 HCWs in four Korean hospitals. HCWs were tested for immunoglobulin G anti-HAV antibodies using commercially available kits. Data including demographic characteristics, occupation, workplace and serological status for other hepatitis viruses were collected. Statistical analyses were conducted to identify variables related to HAV seropositivity. Among the 3696 participants, 2742 (74%) were women and the majority (96%) were aged 20-39 years (median: 28; range: 19-68). Eighteen percent were physicians, 46% nurses, 10% nurses' aides, 11% paramedical technicians and 15% administrative staff. Seropositivity for HAV significantly increased with age (P<0.001): 1.8% for < or =24 years, 14.7% for 25-29 years, 41.8% for 30-34 years, 75.5% for 35-39 years, and 93.7% for > or =40 years. Among those aged 20-39 years, age-specific HAV seroprevalence was significantly lower in physicians than in the other occupational groups (P<0.001). In Korea, mass vaccination to HCWs aged < or =29 years or screening for seropositivity and vaccinating non-immune subjects aged 30-39 years should be considered, especially in physicians.

Post-induction alfentanil reduces sevoflurane-associated emergence agitation in children undergoing an adenotonsillectomy

BACKGROUND

Emergence agitation is a common problem in paediatric anaesthesia, especially after volatile induction and maintenance anaesthesia (VIMA) with sevoflurane. The purpose of this study was to investigate the effect of alfentanil to prevent emergence agitation without delayed recovery after VIMA with sevoflurane in children undergoing an adenotonsillectomy.

METHODS

One hundred and five children, aged 3-10 years, were randomly allocated to receive normal saline (control group), alfentanil 10 microg/kg (A10) or 20 microg/kg (A20) 1 min after loss of the eyelash reflex. Anaesthesia was induced and maintained with sevoflurane. Time to tracheal extubation, recovery time, Paediatric Anaesthesia Emergence Delirium (PAED) scale and emergence behaviour were assessed.

RESULTS

The incidence of severe agitation was significantly lower in the A10 and A20 groups compared with those in the control group (11/32 and 12/34 vs. 24/34, respectively) (P=0.007, 0.006, respectively). PAED scales were significantly different between the three groups (P=0.008), and lower in the A10 and A20 groups than that in the control group (P=0.044, 0.013, respectively). However, the incidence of severe agitation and PAED scale was not different between the A10 and the A20 groups. Time to tracheal extubation and recovery time were similar in all three groups.

CONCLUSION

The administration of alfentanil 10 microg/kg after induction of anaesthesia for children undergoing an adenotonsillectomy under VIMA reduced the incidence of emergence agitation without delaying the recovery time or causing significant hypotension.

Laser assisted ultrasound guided aspiration improves procedure time and reduces number of withdrawals

This study evaluated the performance of in-vitro freehand aspiration of a simulated cyst with ultrasound aspiration guided by a newly designed laser assisted (LA) device. The LA device was equipped with an adjustable light source generating a sector light plane. This laser light plane was parallel to and overlapped the ultrasound acoustical plane, to help with needle positioning. Five operators randomly performed 30 freehand or LA ultrasound guided aspirations of a simulated cyst. The frequency was set at 8 MHz and depth at 4 cm. Procedure time and number of syringe withdrawals were statistically compared before and after using the LA device. Both experienced and inexperienced operators required significantly less time to perform the aspiration and had fewer syringe withdrawals when using the LA device. The LA device provides a reference plane in space, allowing the operator to more accurately position and adjust needle direction. Additional in-vivo testing is required to test the clinical practicability.

The optimal bolus dose of alfentanil for tracheal intubation during sevoflurane induction without neuromuscular blockade in day-case anaesthesia

BACKGROUND

The purpose of this study was to determine the optimal bolus dose of alfentanil required to provide successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane and 60% nitrous oxide without neuromuscular blockade in adult day-case anaesthesia.

METHODS

Twenty-four adults, aged 18-60 years, undergoing general anaesthesia for short ambulatory surgery were enroled into the study. After vital capacity induction, with sevoflurane 5% and 60% nitrous oxide in oxygen, pre-determined dose of alfentanil was injected over 30 s. The dose of alfentanil was determined by modified Dixon's up-and-down method (2 microg/kg as a step size). Ninety seconds after the end of bolus administration of alfentanil, the trachea was intubated. Systolic blood pressure, heart rate and SpO2 were recorded at anaesthetic induction, before, 1 min and 3 min after intubation.

RESULTS

The bolus dose of alfentanil for successful tracheal intubation was 10.7+/-2.1 microg/kg in 50% of patients during inhalation induction. From probit analysis, 50% effective dose (ED(50)) and ED(95) values (95% confidence limits) of alfentanil were 10.7 microg/kg (8.0-12.9 microg/kg) and 14.9 microg/kg (12.9-31.1 microg/kg), respectively.

CONCLUSIONS

Using the modified Dixon's up-and-down method, the bolus dose of alfentanil for successful tracheal intubation was 10.7+/-2.1 microg/kg in 50% of adult patients during inhalation induction using 5% sevoflurane and 60% nitrous oxide in oxygen without neuromuscular blocking agent in day-case anaesthesia.

Dynamic contrast-enhanced MRI of benign prostatic hyperplasia and prostatic carcinoma: correlation with angiogenesis

AIM

To investigate the diagnostic and differential diagnostic values of dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) in prostatic diseases, and to investigate the correlation between the parameters of SI-T curves and angiogenesis.

MATERIALS AND METHODS

Twenty-one patients with proven prostatic carcinoma (Pca) and 29 patients with proven benign prostatic hyperplasia (BPH) were examined using DCE MRI. Diagnostic characteristics for differentiation were examined using threshold values for maximum peak time, enhancement degree, and enhancement rate. Then, the signal intensity-time curves (SI-T curves) were analysed, and the correlations between the parameters of SI-T curves and the expression levels of vascular endothelial growth factor (VEGF) and microvascular density (MVD) were investigated. All patents underwent prostatectomy. DCE MRI and histological findings were correlated.

RESULTS

Pca showed stronger enhancement with an earlier peak time, higher enhancement, and enhancement rate (p<0.05). Regarding the type of SI-T curves, in the BPH group six were type A, 10 were type B, and 13 were type C, whereas in the Pca group, 14 were type A, six were type B, and only one was type C (Chi-square test, chi2=13.57, P<0.005). The VEGF and MVD expression levels of Pca were higher than those of BPH. Peak time was negatively correlated with the expression levels of VEGF and MVD, whereas the enhancement degree and enhancement rate showed positive correlations (Pearson correlation, p<0.05).

CONCLUSION

Based on T2-weighted imaging, DCE MRI curves can help to differentiate benign from malignant prostate tissue. In the present study the type C curve was rarely seen with malignant disease, but these results need confirmation.

The learning curve for hand-assisted laparoscopic colectomy: a single surgeon’s experience

BACKGROUND

Surgical experience and outcomes for hand-assisted laparoscopic colectomy were evaluated to define a learning curve.

METHODS

This study included 60 patients who underwent hand-assisted laparoscopic colectomies performed by a single surgeon. They were analyzed as three consecutive equal groups: A, B, and C. Pearson's chi-square test and one-way analysis of variance (ANOVA) were used to compare differences in demographics and perioperative parameters. Operative times were analyzed to document the learning curve for the procedure.

RESULTS

There were no significant differences between the three groups in terms of age, sex, operative procedure, or comorbidity. Groups B and C showed significantly shorter operative times, significantly earlier recoveries of gastrointestinal function, less blood loss, and shorter hospital stays than group A. The incidence of operative complications was not significantly different among the three groups (35% vs 5% vs 15%; p = 0.07).

CONCLUSIONS

Approximately 21 to 25 cases were needed to achieve proficiency in this series.

Practical and simple circuitry for the measurement of small capacitance

Practical and cost-effective circuitry with high sensitivity has been developed to measure a small capacitance using current compensation method. The circuitry uses an electronic switch to periodically connect or separate the capacitor under test (C(x)) from a reference capacitor (C(r)). When C(x) is connected in parallel with C(r) the total capacitance becomes C(x)+C(r). On the other hand, as C(x) is separated from C(r), the total capacitance is only C(r). This periodic change of the capacitance generates a periodic square-wave output with an amplitude in proportion to the capacitance of C(x). A high sensitivity of DeltaV/DeltaC=202.2 mV/pF has been achieved, making the circuitry a powerful tool in measuring small capacitances. Three applications have been performed to present its capability: (a) displacement, (b) height of liquid, and (c) angle of tilt. The experimental results demonstrate the performance of the circuitry.

Resistance to adefovir dipivoxil in lamivudine resistant chronic hepatitis B patients treated with adefovir dipivoxil

BACKGROUND

Adefovir dipivoxil (ADV) is a potent nucleotide analogue against both the wild-type and lamivudine (LMV) resistant hepatitis B virus (HBV). The cumulative incidence of ADV resistant mutations in the nucleoside/-tide treatment naive chronic hepatitis B patient (CHB) at weeks 48, 96, and 144 was 0, 0.8-3%, and approximately 5.9%, respectively.

AIMS

The aim of this study was to characterise the genotypic and phenotypic mutation profiles to ADV in 67 LMV resistant CHB patients who were treated with ADV.

METHODS

Serum HBV DNA was quantified by real time polymerase chain reaction. The ADV mutant was detected using matrix assisted laser desorption/ionisation time of flight mass spectrometry based genotyping assays, termed restriction fragment mass polymorphism (RFMP).

RESULTS

RFMP analysis revealed that a total of 11 amino acid substitutions developed in the rt domain of the HBV polymerase in nine patients. The cumulative incidence of genotypic ADV resistance at months 12 and 24 was 6.4% and 25.4%, respectively. The rtA181V, rtN236T, and rtA181T mutations were detected in five, four, and two of the 67 patients at treatment months 12-17, 3-19, and 7-20, respectively. Serial quantification of serum HBV DNA revealed that two patients with the rtA181V mutation, with or without the rtN236T mutation, and one patient with the rtA181T mutation displayed HBV DNA rebound.

CONCLUSION

Emergence of the ADV mutation in LMV resistant patients who are treated with ADV appeared to present earlier and more frequently than was reported in previous studies on nucleoside/-tide treatment naive patients.

Clinical relevance of musical murmurs in color-coded carotid and transcranial duplex sonographies

BACKGROUND AND PURPOSE

Musical murmurs (MMs), sometimes called seagull cry, goose cry, honks, or cooing murmur, are murmurs with a single frequency that sounds like a musical tone. Doppler detections usually show mirror-image parallel strings or bands of low to moderate frequency. Musical murmurs are mostly described in cardiac murmurs and have seldom been mentioned in cerebrovascular disease.

METHODS

A retrospective review of 12,000 patients from our neurosonographic data base of the past 7 years was conducted to find patients who had MMs during color-coded carotid and transcranial duplex sonographies.

RESULTS

Sixty-six musical murmurs were found in 60 patients (0.5% of all studied patients). There were 44 men and 16 women with a mean age of 63.8 years. Musical murmurs may occur with or without simultaneous turbulent flows, or very close to a high-intensity frequency (with systolic spindles) turbulent flow. Musical murmurs are detected more frequently in intracranial vessels (94%) than in extracranial cervical arteries. The pathologic changes corresponding to the area of MMs were high-grade stenosis of the arteries (58 MMs), small arteries serving as collateral circulation (5 MMs), carotid cavernous sinus fistulas (2 MMs), and Moyamoya disease (1 MM). Fifty (88%) of 57 patients with stenotic arterial lesions had histories of cerebral infarction or transient ischemic attack, and 64% of the cerebrovascular events occurred on the side appropriate to the MMs.

CONCLUSIONS

The presence of MMs in color-coded carotid duplex and transcranial color-coded duplex sonography imply severe underlying vascular diseases that require prompt treatment. Further cerebral angiographic study is warranted to clarify the underlying pathology in patients with MMs.

Non-traumatic colon perforation in children: a 10-year review

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.

Polarization relaxation induced by a depolarization field in ultrathin ferroelectric capacitors

Time-dependent polarization relaxation behavior induced by a depolarization field E(d) was investigated on high-quality ultrathin SrRuO3/BaTiO3/SrRuO3 capacitors. The E(d) values were determined experimentally from an applied external field to stop the net polarization relaxation. These values agree with those from the electrostatic calculations, demonstrating that a large E(d) inside the ultrathin ferroelectric layer could cause severe polarization relaxation. For numerous ferroelectric devices of capacitor configuration, this effect will set a stricter size limit than the critical thickness issue.

Predictors of prescription of morphine for severe cancer pain by physicians in Korea

BACKGROUND

This study was undertaken to identify predictors of the prescription of strong opioids, which are important for the management of severe cancer pain, by Korean physicians.

METHODS

A questionnaire based on a hypothetical case designed to assess the prescription of morphine by physicians was administered to 800 specialists in the Korea Cancer Association, of whom 147 (18.4%) responded, and to 2200 specialists in the Korean Academy of Family Medicine, of whom 388 (17.6%) responded. We used a multidimensional approach to identify the predictors of prescription of morphine by physicians.

RESULTS

In the hypothetical case scenario, only 16.5% of the respondents stated that they would prescribe morphine for severe cancer pain. Multiple logistic regression analysis showed that physicians with a positive attitude regarding opioid addiction [odds ratio (OR) 2.62; 95% confidence interval (CI) 1.54-4.46], experience of pain assessment (OR 2.09; 95% CI 1.13-3.87), recent residency training (OR 2.27; 95% CI 1.30-4.0) and positive self-evaluation as an oncology specialist (OR 2.60; 95% CI 1.41-4.78) were more likely to prescribe morphine. None of the 13 variables in the knowledge dimension significantly predicted prescription of morphine for severe cancer pain.

CONCLUSIONS

The results of the survey suggest that we need to develop strategies to develop a positive attitude toward opioids, to increase experience in pain assessment and to improve cancer pain management training among Korean physicians.

Hand-assisted laparoscopic sigmoid colectomy: helping hand or hindrance?

BACKGROUND

Hand-assisted laparoscopic colectomy has been introduced as an alternative to the standard laparoscopic technique, but it has not yet been established whether it offers the same benefits. Therefore, we compared the outcome of patients undergoing hand-assisted laparoscopic sigmoid resection (HALSR) to that of those undergoing laparoscopic sigmoid resection (LSR).

METHODS

The study population comprised a sequential series of consecutive patients undergoing elective laparoscopic sigmoid/left colectomy. Values are reported as mean (range).

RESULTS

There were 85 LSR patients and 66 HALSR patients, with no differences in patient demographics or diagnoses. There were slight differences in operative time favoring HALSR (LSR 205 min (90-380) vs HALSR 189 min (120-290); p = 0.07), and the extraction incision was larger in the HALSR group (LSR 6.2 cm (3-25) vs HALSR 8.1 cm (7-12); p < 0.01). There was no difference in time for return of bowel function (LSR 2.8 days (1-15) vs HALSR 2.5 days (1-8); p = 0.31) or length of hospital stay (LSR 5.0 days (2-17) vs HALSR 5.2 days (3-22); p = 0.73). Complications were similar in the two groups (LSR 23% vs HALSR 21%), but there were fewer conversions in the hand-assisted group (HALSR 0% vs LSR 13%; p < 0.01).

CONCLUSIONS

Hand-assisted laparoscopic sigmoid resection yields the same outcomes as standard laparoscopic techniques, but with fewer conversions. Hand-assistance is a helpful innovation that may expand the application of laparoscopic colectomy.

Mutation spectrum of the glucose-6-phosphatase gene and its implication in molecular diagnosis of Korean patients with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD Ia; MIM 232200) is an autosomal recessive inherited metabolic disorder resulting from a deficiency of the microsomal glucose-6-phosphatase (G6Pase), the enzyme that catalyzes the terminal step in gluconeogenesis and glycogenolysis. Various mutations in the G6Pase gene (G6PC) have been found in patients with GSD Ia. To elucidate the spectrum of the G6PC gene mutations, 13 unrelated Korean patients with GSD Ia were analyzed. We were able to identify mutant alleles in all patients, including three known mutations (727G > T, G122D, and T255I) and two novel mutations (P178A and Y128X). The frequency of the 727G > T mutation in Korean patients with GSD Ia was 81% (21/26), which was slightly lower than that (86-92%) in Japanese but much higher than that (44.4%) in Taiwan Chinese. Except one, all patients were either homozygous (9/13) or compound heterozygous (3/13) for the 727G > T mutation; the only patient without the 727G > T mutation was a compound heterozygote for the G122D and Y128X mutations. Our findings suggest that a DNA-based test can be used as the initial diagnostic approach in Korean patients clinically suspected to have GSD Ia, thereby avoiding invasive liver biopsy.

Characterization of crystallographic properties of SMC poly Si using electron backscattered diffraction

Crystallographic properties of silicide mediated crystallization (SMC) polycrystalline silicon (poly Si) and excimer laser annealing (ELA) poly Si were studied by electron backscattered diffraction. Large-grain sized poly Si with a large fraction of low-angle grain boundaries was acquired by SMC, and small-grain sized poly Si with high-angle grain boundaries especially around 60 degrees was acquired by ELA. The thin film transistor (TFT) device characteristics were investigated in view of short-range crystallinity (pattern quality) and long-range crystallinity (misorientation distribution) of the specimens. Short-range crystallinity did not significantly affect the TFT device characteristics, and long-range crystallinity considering the low energy level of special boundaries could be better related to the TFT device characteristics of poly Si.

Kinetic roughening of ion-sputtered Pd(001) surface: beyond the Kuramoto-Sivashinsky model

We investigate the kinetic roughening of Ar+ ion-sputtered Pd(001) surface both experimentally and theoretically. In situ real-time x-ray reflectivity and in situ scanning tunneling microscopy show that nanoscale adatom islands form and grow with increasing sputter time t. Surface roughness W(t) and lateral correlation length xi(t) follow the scaling laws W(t) approximately t(beta) and xi(t) approximately t(1/z) with the exponents beta approximately 0.20 and 1/z approximately 0.20, for an ion beam energy epsilon=0.5 keV, which is inconsistent with the prediction of the Kuramoto-Sivashinsky (KS) model. We thereby extend the KS model by applying the coarse-grained continuum approach of the Sigmund theory to the order of O(inverted Delta(4),h(2)), where h is the surface height, and derive a new term of the form inverted Delta(2)(inverted Delta h)(2) which plays a decisive role in describing the observed morphological evolution of the sputtered surface.

Utilization of microbial biofilms as monitors of bioremediation

A down-well aquifer microbial sampling system was developed using glass wool or Bio-Sep beads as a solid-phase support matrix. Here we describe the use of these devices to monitor the groundwater microbial community dynamics during field bioremediation experiments at the U.S. Department of Energy Natural and Accelerated Bioremediation Research Program's Field Research Center at the Oak Ridge National Laboratory. During the 6-week deployment, microbial biofilms colonized glass wool and bead internal surfaces. Changes in viable biomass, community composition, metabolic status, and respiratory state were reflected in sampler composition, type of donor, and groundwater pH. Biofilms that formed on Bio-Sep beads had 2-13 times greater viable biomass; however, the bead communities were less metabolically active [higher cyclopropane/monoenoic phospholipid fatty acid (PLFA) ratios] and had a lower aerobic respiratory state (lower total respiratory quinone/ PLFA ratio and ubiquinone/menaquinone ratio) than the biofilms formed on glass wool. Anaerobic growth in these systems was characterized by plasmalogen phospholipids and was greater in the wells that received electron donor additions. Partial 16S rDNA sequences indicated that Geobacter and nitrate-reducing organisms were induced by the acetate, ethanol, or glucose additions. DNA and lipid biomarkers were extracted and recovered without the complications that commonly plague sediment samples due to the presence of clay or dissolved organic matter. Although microbial community composition in the groundwater or adjacent sediments may differ from those formed on down-well biofilm samplers, the metabolic activity responses of the biofilms to modifications in groundwater geochemistry record the responses of the microbial community to biostimulation while providing integrative sampling and ease of recovery for biomarker analysis.

In situ bioreduction of technetium and uranium in a nitrate-contaminated aquifer

The potential to stimulate an indigenous microbial community to reduce a mixture of U(VI) and Tc(VII) in the presence of high (120 mM) initial NO3- co-contamination was evaluated in a shallow unconfined aquifer using a series of single-well, push-pull tests. In the absence of added electron donor, NO3-, Tc(VII), and U(VI) reduction was not detectable. However, in the presence of added ethanol, glucose, or acetate to serve as electron donor, rapid NO3- utilization was observed. The accumulation of NO2-, the absence of detectable NH4+ accumulation, and the production of N2O during in situ acetylene-block experiments suggest that NO3- was being consumed via denitrification. Tc(VII) reduction occurred concurrently with NO3- reduction, but U(VI) reduction was not observed until two or more donor additions resulted in iron-reducing conditions, as detected by the production of Fe(II). Reoxidation/remobilization of U(IV) was also observed in tests conducted with high (approximately 120 mM) but not low (approximately 1 mM) initial NO3- concentrations and not during acetylene-block experiments conducted with high initial NO3-. These results suggest that NO3(-)-dependent microbial U(IV) oxidation may inhibit or reverse U(VI) reduction and decrease the stability of U(IV) in this environment. Changes in viable biomass, community composition, metabolic status, and respiratory state of organisms harvested from down-well microbial samplers deployed during these tests were consistent with the conclusions that electron donor additions resulted in microbial growth, the creation of anaerobic conditions, and an increase in activity of metal-reducing organisms (e.g., Geobacter). The results demonstrate that it is possible to stimulate the simultaneous bioreduction of U(VI) and Tc(VII) mixtures commonly found with NO3- co-contamination at radioactive waste sites.

Analysis of Prognostic Factors in 95 Patients with Acinetobacter baumannii Bacteremia

BACKGROUND

Because Acinetobacter baumannii bacteremia is a global problem, we were motivated to characterize this disease in Taiwan.

PATIENTS AND METHODS

We analyzed findings in 95 patients with documented A. baumannii bacteremia between January 1, 1998 and December 31, 2000 (47 men, 48 women; mean age 58.8 years).

RESULTS

The mean length of stay in the hospital was 44.0 days. Clinically, 76 patients had fever and 35 patients developed shock. Fifty patients had respiratory tract infections; 24, urinary tract infections; 11, intra-abdominal infections; three, CNS infections; and two, catheter-related infections. Five patients had primary bacteremia. Empirical antibiotic therapy was initiated at the onset of the clinical signs of infection. Antimicrobial susceptibility test results were variable. 47 patients died and 48 survived; the mortality rate for A. baumannii bacteremia was 45.3% (43/95).

CONCLUSION

Physicians should pay attention to this infection because the early identification of high-risk patients could facilitate prophylaxis and potentially reduce associated problems.

Simultaneous nitrification and denitrification using an autotrophic membrane-immobilized biofilm reactor

AIMS

To develop a laboratory-scale autotrophic membrane-immobilized biofilm reactor to remove nitrogen from drinking water.

METHODS AND RESULTS

A polyvinyl alcohol (PVA) immobilized biofilm, attached to the surface of a silicone tube, was used as the basis of a bioreactor for simultaneous nitrification and denitrification of water. The bioreactor was aerated with air to supply oxygen for nitrification. Pure hydrogen was supplied to the silicone tube and diffused through the membrane wall to feed the biofilm for autotrophic denitrification. The bioreactor was effective for the simultaneous nitrification and denitrification of water after a short period of acclimation, while the biofilm exhibited good resistance to the inhibition of denitrification by dissolved oxygen; the denitrification rate decreased by only 8% as the dissolved oxygen increased from 2 mg l(-1) to saturation.

CONCLUSIONS

By using PVA crosslinked with sodium nitrate to entrap nitrifying and denitrifying sludge on the surface of a silicone tube, a novel bioreactor for simultaneous nitrification and denitrification was developed. In addition to performing as an immobilizing agent to strengthen the biofilm, PVA protected the denitrifying microorganisms to reduce the inhibition by dissolved oxygen under aerobic condition. Therefore, nitrification and denitrification occurred simultaneously within the biofilm. Furthermore, the immobilization technique shortened the acclimation period of the bioreactor.

SIGNIFICANCE AND IMPACT OF THE STUDY

The described space saving and simple to operate bioreactor for nitrogen removal performed autotrophic denitrification to solve the problem of residual carbon in heterotrophic denitrification, and thus is suitable for removing nitrogen from drinking water.

Cochlear vertebral entrapment syndrome: a case report

The authors describe a patient with isolated involvement of vestibulocochlear nerve by a huge vascular loop from vertebral dolichoectasia. No other neurological deficit was found except for unilateral hearing loss. Abnormal brainstem auditory evoked potential study indicated a retrocochlear lesion. The brain computed tomography (CT) and magnetic resonance imaging (MRI) studies demonstrated an abnormally enhanced vascular lesion impinged on the left porus acusticus with a displacement of the brainstem to the right. There was no infarction in the brainstem. A cerebral angiography demonstrated a megadolichoectatic horizontal loop at the intracranial portion of the left vertebral artery. There was no thrombus or atherosclerosis in the vertebrobasilar system. A mechanical compression by a vascular loop is the only possible pathogenesis for hearing loss. The authors diagnose this condition as cochlear vertebral entrapment syndrome.

Impact of herbicides on the abundance and structure of indigenous beta-subgroup ammonia-oxidizer communities in soil microcosms

In this study, mixtures of five herbicide-formulated products (atrazine, dicamba, fluometuron, metolachlor, and sulfentrazone) were applied to soil microcosm columns in increasing concentrations. The toxic impact of herbicides on the indigenous beta-subclass Proteobacteria autotrophic ammonia-oxidizer (beta-AAO) community was assessed. The beta-AAO population abundances were estimated by competitive polymerase chain reaction (PCR) targeting the gene amoA, encoding the alpha-subunit of ammonia monooxygenase. Community structure was examined by PCR and denaturing gradient gel electrophoresis targeting 16S rDNA with band excision and sequence analysis, and by analysis of amoA gene fragment clone libraries. The 16S rDNA analyses showed that a single ribotype of Nitrosospira cluster 3 was the dominant beta-AAO in all treatments. At a finer scale, amoA clone library analysis suggested a shift in community structure corresponding to the 100-ppm application. Competitive PCR indicated significant differences between treatments. The control exhibited relatively stable population abundance over the time period examined. The 10-ppm treatment induced a population increase, but a significant decrease was induced by the 100-ppm application. At 1,000 ppm, the ammonia-oxidizer population dropped below the method detection limit by the first sampling point. An impact on ammonia oxidizers resulting from the application of herbicides was observed, both in abundance and community structure.

The distinct roles that Gln-192 and Glu-217 of factor IX play in selectivity for macromolecular substrates and inhibitors

In this paper, we report functional characterization of positions 192 and 217 (chymotrypsinogen numbering system) in human factor IX and discuss the distinction and similarity of these two sites among the blood coagulation factors. Recombinant factor IXQ192E (residue glutamine at position 192 replaced by glutamic acid), IXQ192K, IXE217D, and IXE217R proteins exhibited 11%, 46%, 39%, and 2% of the wild-type factor IX's clotting activity, respectively. Binding of these variants to factor VIIIa (FVIIIa) was inefficient compared to that of wild-type factor IX, and the dissociation constants doubled for IXQ192E, 3-fold higher for IXQ192K and 4-fold higher for both IXE217D and IXE217R. In the presence of FVIIIa, all variant factor IX hydrolyzed factor X at the catalytic efficiencies correlating with respective clotting activities. However, FVIIIa greatly enhanced the catalytic efficiency of both IXE217 variants to a greater extent (approximately 7 x 10(4)-fold) as compared to its effect on the wild-type factor IXa and the other two IXQ192 variants [by a factor of (1-2) x 10(4)]. Moreover, while both IXQ192 variants demonstrated small substrate selectivity similar to that of wild-type factor IXa, the selectivity of both IXE217 variants was greatly altered. Mutations at position 192 disturbed the interaction of factor IXa with physiological inhibitors. Although all variants formed an SDS-stable complex with antithrombin III (ATIII) equally well in the presence of heparin and were readily inhibited by ATIII in the absence of heparin, activated IXQ192K exhibited a slower stable complex formation with ATIII without heparin. On the other hand, only IXQ192E showed decreased interaction with TFPI. Our results demonstrate that positions 192 and 217 play different roles unique to factor IX in specifying the interaction of factor IX with substrates and inhibitors.

Autotrophic denitrification via a novel membrane-attached biofilm reactor

AIMS

A laboratory-scale autotrophic membrane-attached biofilm reactor was developed to remove nitrate from drinking water.

METHODS AND RESULTS

Hydrogen and carbon dioxide flowed together into the lumem side of a gas-permeable silicone tube. The gases diffused through the membrane wall to feed Alcaligenes eutrophus that formed a biofilm on the surface of the silicone tube for autotrophic denitrification. Hydrogen provided the energy source, and carbon dioxide, besides serving as the carbon source, was employed to neutralize the alkalinity from denitrification. The optimal carbon dioxide concentration in the silicone tube was between 20% and 50%.

CONCLUSION

This study has demonstrated that a gas-permeable silicone tube is a convenient and efficient method to feed A. eutrophus for autotrophic denitrification. Supplying a suitable amount of carbon dioxide together with hydrogen into the silicone tube solved the problem that alkalinity formation caused during denitrification. The pH of the bioreactor was maintained at about 7 to avoid nitrite accumulation, and then the nitrogen removal rate was increased. A high specific nitrogen removal rate (1.6-5.4 g Nm(2)d(-1-1) of surface area of silicone tube) was achieved.

SIGNIFICANCE AND IMPACT OF THE STUDY

In addition to combining the advantages of the hydrogenotrophic denitrification process and a membrane feeding substrate bioreactor (MFSB), this bioreactor achieved a high nitrogen removal rate and is simple to operate. It therefore is highly promising in drinking-water treatment.

Noise and related events in a neonatal intensive care unit

The purposes of this study were to explore noise distribution, its timing, and sources of peak noise in the neonatal intensive care unit (NICU) of a University Hospital in Southern Taiwan. Two surveys on noise distribution and peak noise of the warmer bed were conducted. Noise at radiate heated beds located in the central sites of two areas, one near (Area A) and the other away from (Area B) the nursing station, were measured continuously for one week using an electronic sound-meter. Peak noise with a sound level of > 65 on the A-weighted decibel scale (dBA) and associated sources were recorded for 48 hours. Monitoring periods of peak noise consisted of a weekday and a day on the weekend randomly selected for Area A. Results showed that mean noise levels at the warmer bed in Areas A and B were 62 and 61.4 dBA on average. In over 70% of the total observation time for both areas the sound levels were > 59 dBA. The noise intensity was particularly high between 8 a.m. and 4 p.m. The noise level on the weekend was lower than that on weekdays. During the 48-hour observation period, 4994 peak noises were recorded. Eighty-six percent of these peak noises were within ranges of 65-74 dBA and 90% were human-related factors. The primary non-human related source was monitor alarms. Additionally, peak noises occurred primarily during the 8-11 a.m. and 2-4 p.m. hours on the weekdays and weekends. These results indicate that modifications of staff behavior, care procedures, and apparatus may reduce the noise levels in the NICU.

Diversity and characterization of sulfate-reducing bacteria in groundwater at a uranium mill tailings site

Microbially mediated reduction and immobilization of U(VI) to U(IV) plays a role in both natural attenuation and accelerated bioremediation of uranium-contaminated sites. To realize bioremediation potential and accurately predict natural attenuation, it is important to first understand the microbial diversity of such sites. In this paper, the distribution of sulfate-reducing bacteria (SRB) in contaminated groundwater associated with a uranium mill tailings disposal site at Shiprock, N.Mex., was investigated. Two culture-independent analyses were employed: sequencing of clone libraries of PCR-amplified dissimilatory sulfite reductase (DSR) gene fragments and phospholipid fatty acid (PLFA) biomarker analysis. A remarkable diversity among the DSR sequences was revealed, including sequences from delta-Proteobacteria, gram-positive organisms, and the Nitrospira division. PLFA analysis detected at least 52 different mid-chain-branched saturate PLFA and included a high proportion of 10me16:0. Desulfotomaculum and Desulfotomaculum-like sequences were the most dominant DSR genes detected. Those belonging to SRB within delta-Proteobacteria were mainly recovered from low-uranium (< or =302 ppb) samples. One Desulfotomaculum-like sequence cluster overwhelmingly dominated high-U (>1,500 ppb) sites. Logistic regression showed a significant influence of uranium concentration over the dominance of this cluster of sequences (P = 0.0001). This strong association indicates that Desulfotomaculum has remarkable tolerance and adaptation to high levels of uranium and suggests the organism's possible involvement in natural attenuation of uranium. The in situ activity level of Desulfotomaculum in uranium-contaminated environments and its comparison to the activities of other SRB and other functional groups should be an important area for future research.

Noise distribution of an incubator with nebulizer at a neonatal intensive care unit in southern Taiwan

The purpose of this study was to investigate the noise distribution and sources of peak noise inside an incubator with a nebulizer at a neonatal intensive care unit of a medical center in Southern Taiwan. Sound levels were monitored continuously with an electronic sound-meter for 24 hours daily over a one-week period. Three working hours (day, evening, and night hours) in the weekday and weekend (total 48 hours) were selected randomly from the one-week period of noise survey to observe peak noise at levels > or = 65 dBA. Results revealed that 24.8% of the total monitoring period had sound levels at < or = 59 dBA, 58.9% at 60-64 dBA, 10.7% at 65-69 dBA, and 5.6% at > or = 70 dBA. Furthermore, a total of 947 peak noises > or = 65 dBA were found within the 48 hours, of which 61.5% were in a range of 65-69 dBA, 24% of 70-74 dBA, 9.8% of 75-79 dBA, and 4.8% > or = 80 dBA. Human-related sources, equaling 79%, were the dominant peak noises. These noises included opening and closing doors, banging the incubator hood, conversation among staff, nursing activity inside the incubator, tearing and opening paper or bags, opening and closing trash can lids, and bumping metal carts or other apparatus. Nonhuman-related sources were 21% including alarms of monitors and running of the incubator motor. Results of this study showed that the noise distribution in the incubator with nebulizer was far above a protective limitation of 58 dBA, suggested by the American Academy of Pediatrics in 1974. However, most peak noises could be reduced by modification of staff behavior. Therefore, determinations of noise distribution and sources of peak noise in this study are useful for further noise reduction programs.

Myositis resulting from disseminated cryptococcosis in a patient with hepatitis C cirrhosis

We report a case of myositis that resulted from disseminated cryptococcosis in a patient with hepatitis C cirrhosis. One year after cessation of treatment, the patient remains symptom free with negative results of serum cryptococcal antigen tests and negative culture results.

Tumor necrosis factor-alpha-induced cyclooxygenase-2 expression via sequential activation of ceramide-dependent mitogen-activated protein kinases, and IkappaB kinase 1/2 in human alveolar epithelial cells

The role of p44/42 mitogen-activated protein kinase (MAPK), p38, and c-Jun NH(2)-terminal kinase (JNK) in tumor necrosis factor (TNF)-alpha-induced cyclooxygenase (COX)-2 expression was studied in NCI-H292 epithelial cells. TNF-alpha-mediated COX-2 expression and COX-2 promoter activity were inhibited by the MAPK kinase inhibitor PD98059 or the p38 inhibitor SB203580. Treatment of cells for 10 min with TNF-alpha resulted in activation of p44/42 MAPK, p38, and JNK. C2-ceramide (a cell-permeable ceramide analog), bacterial neutral sphingomyelinase (Smase; an enzyme that degrades sphingomyelin to ceramide), and N-oleoylethanolamine (a ceramidase inhibitor) all induced activation of MAPKs, COX-2 expression, nuclear factor (NF)-kappaB DNA-protein binding, and COX-2 promoter activity. The inactive analog, dihydro-C2-ceramide, had no effect. SMase- or C2-ceramide-induced COX-2 expression and COX-2 promoter activity were also inhibited by PD98059 or SB203580. Glutathione, a neutral SMase inhibitor, attenuated TNF-alpha- or SMase-induced activation of MAPKs, COX-2 expression, and COX-2 promoter activity. TNF-alpha- or C2-ceramide-induced COX-2 promoter activity was inhibited by the dominant negative mutant of extracellular signal-regulated kinase 2, p38, JNK, IkappaB kinase (IKK)1, or IKK2. IKK activity was stimulated by either TNF-alpha or C2-ceramide, and these effects were inhibited by PD98059 or SB203580. All these results suggest that, in NCI-H292 epithelial cells, activation of MAPKs by ceramide contributes to the TNF-alpha signaling that occurs downstream of neutral SMase activation and results in the stimulation of IKK1/2, and NF-kappaB in the COX-2 promoter, followed by initiation of COX-2 expression.

Demineralization of caries-affected transparent dentin by citric acid: an atomic force microscopy study

OBJECTIVES

This study determined recession rates of peritubular dentin and intertubular dentin in citric acid solution (0.018M, pH=2.5) for caries-affected transparent dentin, one of the major components of dentin substrate as altered by caries, with comparisons made with non-carious dentin.

METHODS

Transparent dentin was identified by sagittally sectioning five obviously carious teeth. Sections were then cut through the transparent dentin area perpendicular to the course of the dentinal tubules. Polished dentin samples of the transparent dentin and non-carious dentin were prepared with an internal reference layer and studied at specific intervals for citric acid etching in an atomic force microscope (AFM).

RESULTS

At baseline, transparent dentin was identified by dentinal tubules that were largely occluded with mineral deposits that on etching proved to be acid resistant. Peritubular dentin etched rapidly and linearly over time until it could no longer be measured, yielding etching rates for transparent dentin that could not be distinguished from normal dentin. The normal and transparent intertubular dentin surfaces began etching at nearly the same rate, but then surface recession stabilized after less than 1 microm depth change for both dentin types.

SIGNIFICANCE

Most previous studies have focused on demineralization and bonding to normal dentin, although many bonding procedures involve altered dentin substrates, such as those modified by caries. In this study, peritubular and intertubular dentin from normal and caries-affected dentin exhibited similar behavior. The major difference was the presence of acid resistant mineral in most of tubule lumens in the transparent dentin.

Amorpha-4,11-diene synthase of Artemisia annua: cDNA isolation and bacterial expression of a terpene synthase involved in artemisinin biosynthesis

Artemisia annua, an indigenous plant to Korea, contains an antimalarial sesquiterpene, artemisinin. The first committed step of artemisinin biosynthesis is the cyclization of farnesyl diphosphate by a sesquiterpene synthase to produce an amorphane-type ring system. The aims of this research were to molecularly clone and express amorpha-4,11-diene synthase for metabolic engineering. PCR amplification of genomic DNA with a pair of primers, designed from the conserved regions of sesquiterpene synthases of several plants, produced a 184-bp DNA fragment. This fragment was used in Northern blot analysis as a probe, showing approximately 2.2 kb of a single band. Its sequence information was used to produce 2106 bp of a full-length cDNA sequence including 1641 bp of open reading frame for 546 amino acids (kcs12) through a rapid amplification of cDNA ends (RACE). The deduced amino acid sequence displayed 36% identity with 5-epi-aristolochene synthase of Nicotiana tabacum. A soluble fraction of Escherichia coli harboring kcs12 catalyzed the cyclization of farnesyl diphosphate to produce a sesquiterpene, which was identified through GC-MS analysis as amorpha-4,11-diene.

A survey of 16S rRNA and amoA genes related to autotrophic ammonia-oxidizing bacteria of the beta-subdivision of the class proteobacteria in contaminated groundwater

In this study, we investigated the size and structure of autotrophic ammonia oxidizer (AAO) communities in the groundwater of a contamination plume originating from a mill-tailings disposal site. The site has high levels of dissolved N from anthropogenic sources, and exhibited wide variations in the concentrations of NO3- and NH3 + NH4+. Community structures were examined by PCR-DGGE targeting 16S rDNA with band excision and sequence analysis, and by analysis of amoA fragment clone libraries. AAO population sizes were estimated by competitive PCR targeting the gene amoA, and correlated significantly with nitrate concentration. Most samples revealed novel diversity in AAO 16S rDNA and amoA gene sequences. Both 16S rDNA and amoA analyses suggested that all samples were dominated by Nitrosomonas sp., Nitrosospira sp. being detected in only 3 of 15 samples. This study indicated numerical dominance of Nitrosomonas over Nitrosospira in groundwater, and suggests that groundwater ammonia oxidizers are more similar to those dominating freshwater sediments than bulk soil.

Competitive PCR-DGGE analysis of bacterial mixtures: an internal standard and an appraisal of template enumeration accuracy

Analysis of polymerase chain reaction (PCR) amplified 16S rDNA fragments from environmental samples by denaturing gradients of chemicals or heat [denaturing gradient gel electrophoresis (DGGE) and thermal gradient gel electrophoresis (TGGE)] within polyacrylamide gels is a popular tool in microbial ecology. Difficulties in acceptance of the technique and interpretation of the results remain, due to its qualitative nature. In this study we have addressed this problem by the construction and evaluation of a quantitative standard for incorporation into test DNA samples. The standard was based on a naturally occurring 16S rRNA gene carried by the X-endosymbiont of the psyllid Anomoneura mori, a gamma-proteobacterium. This sequence is the most AT-rich 16S rDNA gene recovered from any cultured organism or environmental sample described to date, and a specifically amplified rDNA fragment denatured under exceptionally low stringency denaturing conditions. The native sequence was modified to incorporate perfect matches to the PCR primers used. The efficiency of amplification of this standard in comparison to a range of 16S rDNA sequences and the errors involved in enumerating template molecules under a range of PCR conditions are demonstrated and quantified. Tests indicated that highly accurate counts of released target molecules from a range of bacterial cells could be achieved in both laboratory mixtures and compost.