Enantioselective Radical-Type 1,2-Alkoxy-Phosphinoylation to Styrenes Catalyzed by Chiral Vanadyl Complexes

A series of vanadyl complexes bearing 3-t-butyl-5-bromo, 3-aryl-5-bromo, 3,5-dihalo-, and benzo-fused N-salicylidene-tert-leucinates was examined as catalysts for 1,2-alkoxy-phosphinoylation of 4-, 3-, 3,4-, and 3,5-substituted styrene derivatives (including Me/t-Bu, Ph, OR, Cl/Br, OAc, NO₂ , C(O)Me, CO₂ Me, CN, and benzo-fused) with HP(O)Ph₂ in the presence of t-BuOOH (TBHP) in a given alcohol or cosolvent with MeOH. The best scenario involved the use of 5 mol % 3-(2,5-dimethylphenyl)-5-Br (i.e., 3-DMP-5-Br) catalyst at 0 °C in MeOH. The desired catalytic cross coupling reactions proceeded smoothly with enantioselectivities of up to 95 % ee of (R)-configuration as confirmed by X-ray crystallographic analysis of several recrystallized products. The origin of enantiocontrol and homolytic substitution of the benzylic intermediates by vanadyl-bound methoxide and radical type catalytic mechanism were proposed.

Cinchona Alkaloid-Inspired Urea-Containing Autophagy Inhibitor Shows Single-Agent Anticancer Efficacy

Autophagy is upregulated in response to metabolic stress, a hypoxic tumor microenvironment, and therapeutic stress in various cancers and mediates tumor progression and resistance to cancer therapy. Herein, we identified a cinchona alkaloid derivative containing urea (C1), which exhibited potential cytotoxicity and inhibited autophagy in hepatocellular carcinoma (HCC) cells. We showed that C1 not only induced apoptosis but also blocked autophagy in HCC cells, as indicated by the increased expression of LC3-II and p62, inhibition of autophagosome-lysosome fusion, and suppression of the Akt/mTOR/S6k pathway in the HCC cells. Finally, to improve its solubility and efficacy, we encapsulated C1 into PEGylated lipid-poly(lactic-co-glycolic acid) (PLGA) nanoscale drug carriers. Systemic administration of nanoscale C1 significantly suppressed primary tumor growth and prevented distant metastasis while maintaining a desirable safety profile. Our findings demonstrate that C1 combines autophagy modulation and apoptosis induction in a single molecule, making it a promising therapeutic option for HCC.

Risk of post-contrast acute kidney injury in emergency department patients with sepsis

INTRODUCTION

Although computed tomography (CT) is a useful tool for exploring occult infection in patients with sepsis in the emergency department, the potential nephrotoxicity of contrast media is a major concern. Our study aimed to investigate the association between use of contrast-enhanced CT and the risks of acute kidney injury and other adverse outcomes in patients with sepsis.

METHODS

In total, 587 patients with sepsis who underwent CT scan (enhanced CT group: 105, non-enhanced CT group: 482) from January 2012 to December 2016 at a tertiary referral centre were enrolled in this retrospective analysis, and propensity score matching was performed to minimise the selection bias. The length of stay, incidences of acute kidney injury and emergent dialysis, and short-term mortality were compared between the two groups.

RESULTS

Compared with patients in the non-enhanced CT group, patients in the contrast-enhanced CT group did not have increased risks of acute kidney injury (odds ratio [OR]=1.38, 95% confidence interval [CI]=0.55-3.43; P=0.489), emergent dialysis (OR=1.31, 95% CI=0.47-3.68; P=0.602), or short-term mortality (OR=0.90, 95% CI=0.48-1.69; P=0.751). In addition, there was no significant difference in the median length of hospital stay between survivors in the two groups (20 vs 19 days, P=0.742).

CONCLUSIONS

Intravenous contrast administration during CT scanning was not associated with prolonged length of hospital stay in patients with sepsis in an emergency setting. Moreover, the use of contrast-enhanced CT was not associated with increased risks of acute kidney injury, emergent dialysis, or short-term mortality.

Prevention of Postdental Procedure Bacteremia: A Network Meta-analysis

Postdental procedure bacteremia is common and troublesome. The comparative efficacy of multiple prophylactic interventions is unclear. We compared the efficacy of interventions for the prevention of postdental procedure bacteremia. We conducted a review of ClinicalKey, Cochrane CENTRAL, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov from inception to December 4, 2018. Randomized controlled trials that evaluated prophylactic interventions for the prevention of postdental procedure bacteremia were eligible. The primary outcome was the incidence of postdental procedure bacteremia. A total of 24 trials were included with 2,147 participants. Our network meta-analysis demonstrated that intravenous administration of 1,000/200 mg of amoxicillin/clavulanate provided the least incidence of postdental procedure bacteremia among all the prophylactic interventions (odds ratio = 0.03, 95% CI = 0.00 to 0.63) as compared with the placebo/controls. Oral 3 g of amoxicillin had the least incidence of postdental procedure bacteremia among all oral or topical forms of prophylactic interventions (odds ratio = 0.10, 95% CI = 0.02 to 0.44) as compared with the placebo/controls. No serious adverse events, such as anaphylactic shock, mortality, and the development of antibiotic-resistant bacteria, were reported. None of the included subjects were of high risk of infectious endocarditis. Our network meta-analysis demonstrates that intravenous amoxicillin/clavulanate and oral amoxicillin might be the best prophylactic interventions in preventing postdental procedure bacteremia among all the oral/topical forms of interventions for the overall populations.

Mixed NiO/NiCo2O4 Nanocrystals Grown from the Skeleton of a 3D Porous Nickel Network as Efficient Electrocatalysts for Oxygen Evolution Reactions

Mixed NiO/NiCo₂O₄ nanocrystals grown in situ from the skeleton of a 3D porous nickel network (3DPNN) were prepared with a simple hydrothermal method followed by a low temperature calcination, exhibiting outstanding electrocatalytic efficiencies toward oxygen evolution reactions (OER). The 3DPNN was prepared with a novel leaven dough method and served as both the nickel source for growth of the mixed NiO/NiCo₂O₄ nanocrystals and the charge transport highway to accelerate the sluggish kinetics of the OER. The mixed NiO/NiCo₂O₄ nanocrystals exhibited pronounced synergistic effects to achieve a high mass activity of 200 A g^-1 at the catalyst mass loading of 0.5 mg cm^-2, largely outperforming the corresponding single component nanocrystal systems, NiO (5.87) and NiCo₂O₄ (9.35). The NiO/NiCo₂O₄@3DPNN composite electrocatalyst achieved a low overpotential of 264 mV at the current density of 10 mA cm^-2 and 389 mV at the practically high current density of 250 mA cm^-2, which compete favorably among the top tier of previously reported OER electrocatalysts. Moreover, it exhibited good stability even at the high current density of 250 mA cm^-2, showing only 9.40% increase in working applied potential after a continuous 12 h operation. The present work demonstrates a new design for highly efficient OER catalysts with in situ growth of mixed oxide nanocrystals of pronounced synergistic effects.

Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming

Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming. Furthermore, we show that methane fluxes from dissociating hydrates were considerably smaller than present methane seepage rates implying that gas hydrates were not a major source of methane to the oceans, but rather acted as a dynamic seal, regulating methane release from deep geological reservoirs.

Methane seepage from continental slopes has been attributed to gas hydrate dissociation induced by anthropogenic bottom water warming. Here, the authors show that hydrates dissociated before the Anthropocene when the isostatic rebound induced by deglaciation of the Arctic ice sheet outpaced eustatic sea-level rise.

Traumatic Dissections of Bilateral Internal carotid Artery with Aneurysms Formation

Carotid artery dissection is an unusual complication of blunt neck trauma with high mortality and severe neurological deficits. Traumatic bilateral dissections and dissecting aneurysms are extremely rare. A 17-year-old male presented to our emergency department with sudden onset of right hemiparesis and aphasia. Initial computed tomography scan of head and neck showed no remarkable finding. On the second day, a magnetic resonance angiography of head and neck demonstrated bilateral extracranial internal carotid artery dissections. The diagnosis of traumatic carotid artery dissection for emergency physicians is difficult because of the absence or delayed onset in symptomatology. Magnetic resonance angiography is currently considered as an appropriate initial diagnostic tool for carotid artery injury. In clinical practice, early diagnosis by keeping a high index of suspicions is required by emergency physicians.

Efficient, designable, and broad-bandwidth optical extinction via aspect-ratio-tailored silver nanodisks

Subwavelength resonators, ranging from single atoms to metallic nanoparticles, typically exhibit a narrow-bandwidth response to optical excitations. We computationally design and experimentally synthesize tailored distributions of silver nanodisks to extinguish light over broad and varied frequency windows. We show that metallic nanodisks are 2-10x more efficient in absorbing and scattering light than common structures, and can approach fundamental limits to broadband scattering for subwavelength particles. We measure broadband extinction per volume that closely approaches theoretical predictions over three representative visible-range wavelength windows, confirming the high efficiency of nanodisks and demonstrating the collective power of computational design and experimental precision for developing new photonics technologies.

Wired and wireless convergent extended-reach optical access network using direct-detection of all-optical OFDM super-channel signal

We propose and demonstrate the feasibility of using all-optical orthogonal frequency division multiplexing (AO-OFDM) for the convergent optical wired and wireless access networks. AO-OFDM relies on all-optically generated orthogonal subcarriers; hence, high data rate (> 100 Gb/s) can be easily achieved without hitting the speed limit of electronic digital-to-analog and analog-to-digital converters (DAC/ADC). A proof-of-concept convergent access network using AO-OFDM super-channel (SC) is demonstrated supporting 40 - 100 Gb/s wired and gigabit/s 100 GHz millimeter-wave (MMW) ROF transmissions.

Synthesis and characterization of Pt nanoparticles with different morphologies in mesoporous silica SBA-15 for methanol oxidation reaction

Mesoporous SBA-15 silica materials functionalized with and without carboxylic acid groups were used to effectively control the morphology of Pt crystals, and the materials thus obtained were applied to methanol oxidation reactions. The Pt particles aggregated to form long spheroids inside the channels in pure SBA-15. When carboxylic acid groups were utilized, the SBA-15(-COOH) material facilitated the formation of higher Pt surface area, smaller Pt nanoparticles and nearly spherical shape due to the strong interaction between Pt(4+) ions and carboxylic acid on SBA-15. The Pt(4+) ions on the SBA-15(-COOH) material can be directly transformed to reduced Pt particles during calcination. The methanol oxidation activity on a Pt surface is strongly dependent on the shape of Pt particles. The near-spherical Pt nanoparticles on the SBA-15(-COOH) exhibited higher catalytic activity during methanol oxidation than Pt catalysts on unmodified SBA-15. The near-spherical Pt particles on the SBA-15(-COOH) contained large numbers of terrace sites on their surfaces, which led to high efficiency during methanol oxidation.

Fundamental limits to extinction by metallic nanoparticles

We show that there are shape-independent upper bounds to the extinction cross section per unit volume of dilute, randomly arranged nanoparticles, given only material permittivity. Underlying the limits are restrictive sum rules that constrain the distribution of quasistatic eigenvalues. Surprisingly, optimally designed spheroids, with only a single quasistatic degree of freedom, reach the upper bounds for four permittivity values. Away from these permittivities, we demonstrate computationally optimized structures that surpass spheroids and approach the fundamental limits.

InGaN quantum dot formation mechanism on hexagonal GaN/InGaN/GaN pyramids

Growing InGaN quantum dots (QDs) at the apex of hexagonal GaN pyramids is an elegant approach to achieve a deterministic positioning of QDs. Despite similar synthesis procedures by metal organic chemical vapor deposition, the optical properties of the QDs reported in the literature vary drastically. The QDs tend to exhibit either narrow or broad emission lines in the micro-photoluminescence spectra. By coupled microstructural and optical investigations, the QDs giving rise to narrow emission lines were concluded to nucleate in association with a (0001) facet at the apex of the GaN pyramid.

The analysis of decomposition methods for support vector machines

The support vector machine (SVM) is a new and promising technique for pattern recognition. It requires the solution of a large dense quadratic programming problem. Traditional optimization methods cannot be directly applied due to memory restrictions. Up to now, very few methods can handle the memory problem and an important one is the "decomposition method." However, there is no convergence proof so far. In this paper, we connect this method to projected gradient methods and provide theoretical proofs for a version of decomposition methods. An extension to bound-constrained formulation of SVM is also provided.We then show that this convergence proof is valid for general decomposition methods if their working set selection meets a simple requirement.

Differentially transcribed genes in skeletal muscle of Duroc and Taoyuan pigs

The objective of this study was to compare gene transcription profiles of LM between two pig breeds, Duroc and Taoyuan, which display dramatically different postnatal muscle growth. We isolated LM from neonatal pigs, and the Duroc muscle length and mass were greater (P < 0.01) than for Taoyuan pigs; however, insignificant differences in the muscle fiber area and the percentage of fiber types were found. A human high-density complementary DNA (cDNA) microarray consisting of 9,182 probes was used to compare gene transcription profiles of LM between the two breeds. The results showed that the transcription level of 73 genes and 44 genes in Duroc LM were upregulated and down-regulated by at least 1.75-fold (P < 0.05) compared with Taoyuan, respectively. The strongly upregulated genes in Duroc pigs included those encoding the complex of myofibrillar proteins (e.g., myosin light and heavy chains, and troponin), ribosomal proteins, transcription regulatory proteins (e.g., skeletal muscle LIM protein 1 [SLIM1] and high-mobility group proteins), and energy metabolic enzymes (e.g., electron-transferring flavo-protein dehydrogenase, NADH dehydrogenase, malate dehydrogenase, and ATP synthases). The highly transcribed genes that encode energy metabolic enzymes indicate a more glycolytic metabolism in Duroc LM, thereby favoring carbohydrates rather than lipids for use as energy substrates in this tissue. The over-transcribed genes that encode skeletal muscle-predominant proteins or transcription regulators that control myogenesis and/or muscle growth suggest a general mechanism for the observed higher rate of postnatal muscle growth in Duroc pigs. The transcription of one such gene, SLIM1, was more highly transcribed (P < 0.01) in Duroc LM at birth and at postnatal d 7 than in Taoyuan. The transcription of SLIM1 increased (P < 0.05) in Duroc LM from neonate through 7 d of age, whereas its transcription remained essentially constant in Taoyuan during this period. These results suggest that SLIM1 may be useful for the development of markers associated with the postnatal muscle growth of pigs.

Cytotoxicity induced by grape seed proanthocyanidins: role of nitric oxide

Grape seed proanthocyanidin extract (GPSE) at high doses has been shown to exhibit cytotoxicity that is associated with increased apoptotic cell death. Nitric oxide (NO), being a regulator of apoptosis, can be increased in production by the administration of GSPE. In a chick cardiomyocyte study, we demonstrated that high-dose (500 microg/ml) GSPE produces a significantly high level of NO that contributes to increased apoptotic cell death detected by propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. It is also associated with the depletion of intracellular glutathione (GSH), probably due to increased consumption by NO with the formation of S-nitrosoglutathione. Co-treatment with L-NAME, a NO synthase inhibitor, results in reduction of NO and apoptotic cell death. The decline in reduced GSH/oxidized GSH (GSSG) ratio is also reversed. N-Acetylcysteine, a thiol compound that reacts directly with NO, can reduce the increased NO generation and reverse the decreased GSH/GSSG ratio, thereby attenuating the cytotoxicity induced by high-dose GSPE. Taken together, these results suggest that endogenous NO synthase (NOS) activation and excessive NO production play a key role in the pathogenesis of high-dose GSPE-induced cytotoxicity.

A study of silicon carbide synthesis from waste serpentine

There are 60000 tons of serpentine wastes produced in year 2004 in Taiwan. This is due to the well-developed joints in the serpentine ore body as well as the stringent requirements of the particle size and chemical composition of serpentine by iron making company. The waste also creates considerable environmental problems. The purpose of this study is reutilization of waste serpentine to produce a high value silica powder after acid leaching. These siliceous microstructure products obtained from serpentine would be responsible for high reactivity and characteristic molecular sieving effect. In this study, the amorphous silica powder was then synthesized to silicon carbide with the C/SiO(2) molar ratio of 3. The experiment results show that silicon carbide can be synthesized in 1550 degrees C. The formed silicon carbide was whisker beta type SiC which can be used as raw materials for industry.

Comparison of the severity of illness scoring systems for critically ill cirrhotic patients with renal failure

BACKGROUND

Mortality rates of cirrhotic patients with renal failure admitted to the medical intensive care unit (ICU) are high. End-stage liver disease is frequently complicated by disturbances of renal function. This investigation is aimed to compare the predicting ability of acute physiology, age, chronic health evaluation II and III (APACHE II and III), sequential organ failure assessment (SOFA), and Child-Pugh scoring systems, obtained on the first day of ICU admission, for hospital mortality in critically ill cirrhotic patients with renal failure.

METHODS

Sixty-seven patients with liver cirrhosis and renal failure were admitted to ICU from April 2001-March 2002. Information considered necessary for computing the Child-Pugh, SOFA, APACHE II and APACHE III score on the first day of ICU admission was prospectively collected.

RESULTS

The overall hospital mortality rate was 86.6%. Liver disease was most commonly attributed to hepatitis B viral infection. The development of renal failure was associated with a history of gastrointestinal bleeding. Goodness-of-fit was good for SOFA, APACHE II and APACHE III scores. The APACHE III and SOFA models reported good areas under receiver operating characteristic curve (0.878 +/- 0.050 and 0.868 +/- 0.051, respectively).

CONCLUSION

Renal failure is common in critically ill patients with cirrhosis. The prognosis for cirrhotic patients with renal failure is poor. APACHE III and SOFA showed excellent discrimination power in this group of patients. They are superior to APACHE II and Child-Pugh scores in this homogenous group of patients.

Dispersion of organic pigments using supercritical carbon dioxide

This research describes dispersion of organic pigments using supercritical fluids. With low surface tension and high diffusivity of fluids in supercritical states, aggregated particles may be effectively wetted and swelled to form the primary constituent of the dispersing solution by volume. In this paper, the conditions of temperature and pressure are used to control the density of supercritical carbon dioxide subject to PGMEA as cosolvent for dispersing organic powder in a solution. As shown from measurement with a laser scattering particle analyzer, the average diameter of phthalocyanine green 36 with the haloid structure can be significantly reduced to 93.5 nm; for aminoanthraquinone red containing and amino group (-NH(2)) and phthalocyanine blue 15:6 with symmetry benzene and inner hydrogen bond, the mean particle sizes are 178.5 and 188.7 nm, respectively, using supercritical CO(2). Additionally, the transmittance of UV light is used to confirm the dispersing performance in this study.

Blue luminescence of Au nanoclusters embedded in silica matrix

Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO(2) matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar(+) irradiation on Au [40 nm]/SiO(2) at various fluences and subsequent annealing at high temperature. The blue bands above approximately 3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blueshift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals formalism with generalized gradient approximation for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states for different strain values in order to explain the blueshift of approximately 0.1 eV with decreasing cluster size around L-symmetry point.

Bronchial entrapment of a chicken bone for 14 years

Prolonged airway entrapment of a foreign body is a rare occurrence. We report a case of a chicken bone retained in the right main bronchus for 14 years and highlight the importance of a foreign body in the airway in the differential diagnosis of chronic and intractable cough.

Broadband infrared generation with noncollinear optical parametric processes on periodically poled LiNbO(3)

Broadband signal and idler generation based on the spectral retracing behavior in noncollinear phase matching of optical parametric generation in periodically poled LiNbO(3) (PPLN) is reported. Using PPLN of 29.5-mum quasi-phase-matching period and a Q-switched Nd:YAG laser as a pump, we obtained a broad signal spectrum from 1.66 to 1.96 mum and corresponding idler wavelengths from 2.328 to 2.963 mum. The experimental results were consistent with theoretical predictions. Circular and elliptical pump beams were also compared.

Comparison of the APACHE II and APACHE III scoring systems in patients with respiratory failure in a medical intensive care unit

BACKGROUND AND PURPOSE

This retrospective study compared the capability of the Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scoring systems to predict outcome and determined the independent predictors of survival in these scoring systems for patients with respiratory failure in a medical intensive care unit (ICU).

MATERIALS AND METHODS

Seven hundred and eight patients with respiratory failure admitted to the medical ICU throughout a 9-year period were studied. Patients with an ICU stay of less than 24 hours, patients under 12 years of age, and burn and surgery patients were excluded. APACHE scores were calculated at 24 hours after admission. Student's t-test was used to compare the total APACHE scores of survivor and non-survivor groups. Multivariate logistic regression analysis was used to determine which variables were predictors of mortality. The discriminative power of APACHE scores to predict in-hospital mortality was studied by the area under the receiver operating characteristic curves of the APACHE II and APACHE III systems, respectively.

RESULTS

Both systems showed a significant association between higher scores and higher mortality. The APACHE II system under-predicted the actual hospital mortality rate. The APACHE III systems had a higher discriminative power (area 0.7462) than the APACHE II systems (area 0.6856; p < 0.05). The independent predictors of survival as assessed by APACHE II and III systems were respiratory rate, arterial oxygen pressure, oxygen gradient between alveoli and artery, serum creatinine concentration, and the presence of neurologic abnormalities.

CONCLUSIONS

The APACHE III systems has greater discriminative power than the APACHE II systems for predicting in-hospital mortality. The variables of oxygenation, mean artery pressure, respiratory rate, serum creatinine concentration, and Glasgow Coma Scale play important roles in predicting survival for patients with respiratory failure.

Measurement of the size and orientation of human masseter and medial pterygoid muscles

To gain a better understanding of biting and chewing performance, the size and orientation of the masseter and medial pterygoid muscles in living humans were studied. Twenty-seven young males having complete dentition, class I dental occlusion and normal muscle and jaw function were examined using magnetic resonance images of the head between the zygomatic arch and hyoid bone. The sections were parallel to the palatal plane, and the thickness was 3 mm without a gap. A computer software program (Medical Dental Image, MDI) was developed to identify and calculate the area of each cross section of the muscle, and the volume of the muscle was then estimated. The axis of the muscle was determined by connecting the centroids of the sections in the lower and upper 1/3 of the whole muscle. The effective muscle cross section area was then calculated by resectioning the muscle perpendicularly to the muscle axis. It was found that the mean masseter muscle volume was around 31 cm3, and that the mean medial pterygoid muscle volume was 11 cm3. Their mean effective cross section areas were around 6.2 cm2 and 3.5 cm2, respectively. The axis of the masseter muscle was more perpendicular to the palatal plane and parallel to the sagittal plane than was the medial pterygoid muscle. The results suggest that the use of magnetic resonance images (MRI) is an effective noninvasive measurement technique for determining the size and orientation of masseter and medial pterygoid muscles. This technique can be employed in future studies on human bite force evaluation and masticatory function.

Low frequency of rearrangement of TRK protooncogene in Chinese thyroid tumors

The TRK protooncogene (NTRK1) encodes a cell-surface transmembrane tyrosine kinase (TK) acting as a receptor for nerve growth factor. Oncogenic potential in thyrocytes results from replacing the 5' portion by regulatory parts of other genes, leading to constitutive TK expression. In Italy, human papillary thyroid carcinoma (PTC) shows a frequent activation (50%) of the TK receptor genes NTRK1 and RET. Both genes undergo oncogenic rearrangements by the same mechanism. We previously reported high frequency (6/11) of rearrangement of the RET protooncogene in Chinese PTCs. Wide differences in the frequency (0-10.9%) of the NTRK1 rearrangement in PTCs have been reported in different populations. To investigate the frequency of TRK protooncogene rearrangement in Chinese thyroid tumors, we performed reverse transcriptase polymerase chain reaction to amplify specific TRK rearrangement transcripts. We examined thyroid tumors of 40 patients, including 14 papillary carcinomas, 4 follicular carcinomas, 1 Hurthle cell carcinoma, 1 insular carcinoma, and 20 nodular goiters. NF874 NIH3T3, NF723 NIH3T3, NF861 NIH3T3, and NF881 NIH3T3 were used as controls for TRK-T3, TRK-T2, TRK-T1, and TRK, respectively. No known TRK protooncogene rearrangements were detected among the 40 thyroid tumors in our studies. We suggest that the TK receptor NTRK1 activation seems less important than RET activation in PTCs in the Chinese population.

Replication of hepatitis C virus in ascitic mononuclear cells with development of distinct viral quasispecies

To investigate whether distinct compositions of viral quasispecies developed in the ascitic fluid of patients with late-stage chronic hepatitis C virus (HCV) infection, samples of various origins, including ascitic fluid and ascitic mononuclear cells (AMCs), were analyzed by the method of single-strand conformation polymorphism (SSCP). Subsequently, the major species were isolated, sequenced, and subjected to phylogenetic analysis. Of 42 patients analyzed, HCV-RNA was detectable in the AMCs of 25 patients. SSCP analysis indicated that the compositions of viral quasispecies among samples of different origins were markedly different in this group of patients. Phylogenetic analysis revealed that the ascitic-fluid-derived clones were most closely related to the AMC-derived clones. Minus-strand HCV-RNA was detectable in 5 of them. Our data suggest that HCV can replicate in the AMCs of patients with late-stage chronic HCV, which results in the development of distinct viral quasispecies.

Ethambutol-induced psychosis: a case report

Clinically, ethambutol (EMB)-induced psychosis is rare. In our review of the literature, most cases of antituberculosis agent-associated psychoses were caused by isoniazid (INH). We report the case of a 51-year-old man with suspected tuberculosis (TB) pleurisy. An anti-TB trial with INH, rifampicin and EMB was given initially. Dizziness, disorientation, and auditory and visual hallucinations developed after seven days of therapy. Laboratory examinations, including routine biochemistry tests, serum titer of antinuclear antibodies, cerebrospinal fluid analysis and computerized tomography of the head showed no abnormal findings. Following discontinuation of anti-TB agents, the psychiatric symptoms subsided. When the patient was challenged with EMB, the same psychiatric symptoms recurred, but resolved again after discontinuation of EMB. It is important to be aware that EMB can induce psychosis when anti-TB medications are prescribed.

Small cell lung carcinoma associated with paraneoplastic limbic encephalitis

Limbic encephalitis is an unusual presentation of paraneoplastic syndrome. We report a case of small cell lung carcinoma associated with limbic encephalitis. A 67-year-old man presented with convulsions, memory impairment, and neuropsychiatric disturbances as initial symptoms. Subsequently, small cell lung carcinoma was diagnosed by bronchoscopic biopsy. The cerebrospinal fluid studies, electroencephalography, and magnetic resonance imaging findings had distinctive features compatible with paraneoplastic limbic encephalitis. The neuropsychiatric symptoms improved significantly after six cycles of systemic chemotherapy and adjuvant radiotherapy, resulting in partial remission of the tumor. A follow-up computed tomography scan of the head showed no evidence of intracranial metastasis 7 months after the diagnosis of cancer. Limbic encephalitis may be an initial manifestation of lung cancer. Greater awareness for diagnosis and early treatment of the primary tumor offers the best chance for improvement in patients with lung cancer presenting with limbic encephalitis.

Evaluation of biting performance with standardized test-foods

Human masseter muscle is the main power source used for crushing or grinding the foods. Its size is regarded as an determining factor of chewing force and function. A system of measuring the masseter muscle volume from MR images was developed in this study. For a better understanding of the masseter muscle function, a standardized test-food developed in our laboratory was used. Twelve male subjects having complete dentition and healthy masticatory function were used to chew the test-foods. The EMG muscle activity of the masseter muscle during breaking and chewing the test-foods was observed. It was found that the muscle volume was positively related to the body size. The increase of the muscle activity during breaking and chewing was almost parallel to the increase of the test-food hardness, and the increase was mostly in the duration of muscle contraction. It was concluded that the measurement of masseter muscle volume is possible, and our test-foods can be used for chewing function examination with high reliability. Within a certain level of hardness, harder food requires longer muscle contraction time instead of stronger muscle force to break and chew the food.

Using a grating structure for phase compensation in achieving an efficient round-trip optical parametric process in periodically poled lithium niobate with an incomplete quasi-phase-matching period

An incomplete period of the last quasi-phase-matching (QPM) segment in a periodically poled nonlinear crystal represents a key problem in implementing a nonlinear wavelength-conversion device with round-trip or oscillating waves of interaction. Such a segment at the crystal end implies broken QPM periodicity for the reflected waves of interaction. We demonstrate numerically that with a grating structure at the crystal end for the reflecting signal the wavelength-dependent phase shift at Bragg reflection can compensate for the phase mismatch of the reflected signal, idler, and pump of an optical parametric process. Therefore, by slightly shifting the signal wavelength we can maintain the phase-matching condition with any length of the last QPM segment. It is shown that with a grating structure the conversion efficiency of the round-trip optical parametric process can always be optimized.

Dietary pantothenic acid requirement of juvenile grass shrimp, Penaeus monodon

A feeding trial was conducted to estimate the minimal dietary pantothenic acid (PA) requirement for juvenile grass shrimp, Penaeus monodon. Purified diets with seven levels (0, 20, 40, 60, 120, 240, and 480 mg/kg) of supplemental PA were fed to P. monodon (mean weight 0.88 +/- 0.01 g) for 8 wk. The level of PA detected in the unsupplemented diet was 0.02 mg/kg. Each diet was fed to three replicate groups of shrimp. Feed efficiencies (FE) and protein efficiency ratios were highest in shrimp fed the diets supplemented with 120, 240, and 480 mg PA/kg diet, followed by the groups fed 60 mg/kg, then 40 mg/kg, and finally the unsupplemented control group (P < 0.05). Shrimp fed diets supplemented with PA had significantly higher survival percentages and lower hepatopancreatic lipid concentration than those fed the unsupplemented, control diets. Broken-line regression analyses of weight gain percentage and hepatopancreatic CoA and PA concentrations of the shrimp indicated that the adequate dietary PA concentration in growing P. monodon is 101-139 mg/kg.

Adrenal insufficiency caused by primary aggressive non-Hodgkin's lymphoma of bilateral adrenal glands: report of a case and literature review

A 64-year-old woman was hospitalized because of poor general condition, gastrointestinal upset, unexplained fever, electrolyte imbalances, and an incidental finding of bilateral huge adrenal masses on computerized tomography (CT) of the abdomen. Non-Hodgkin's lymphoma (NHL) of B-cell origin was proven by ultrasound-guided aspiration biopsy of the left adrenal gland. Meanwhile, primary adrenal insufficiency was confirmed by her low serum cortisol level, high ACTH level, and inadequate adrenal response to the rapid ACTH stimulation test. The diagnosis of primary adrenal NHL was supported by detailed physical examinations, bone marrow examination, and such imaging studies as CT scan and sonography. She received three courses of chemotherapy with cyclophosphamide, vincristine, and prednisolone and there was an initial transient response, but she died of sepsis and progression of NHL three and a half months later.

Rapid progression of Barrett's esophagus to metastatic esophageal carcinoma in a patient with chronic lymphocytic leukemia

Barrett's esophagus is a common premalignant condition that predisposes to the development of adenocarcinoma of the esophagus through a process of transformation from metaplasia to dysplasia and then carcinoma. Periodic endoscopic surveillance with multiple biopsies is adopted by most physicians to detect dysplasia or early carcinoma. We report a case of an 80-year-old white man with chronic lymphocytic leukemia (CLL) who had periodic endoscopic surveillance without any evidence of dysplasia or cancer, and who died of metastatic carcinoma of the esophagus only 18 months after his last upper endoscopic examination. We suspect that the relative immunosuppressed state resulting from his CLL was the major contributor to the rapid progression of the Barrett's esophagus to cancer. Patients with CLL have higher risk of second cancers, and several cases of aggressive carcinomas have been reported in association with CLL. This is the first case report of metastatic esophageal cancer arising in Barrett's esophagus in a patient with CLL. This case suggests that we might need a more aggressive surveillance strategy for Barrett's esophagus in patients with CLL or other immunocompromised conditions.

Meta-analysis and cost comparison of polyethylene glycol lavage versus sodium phosphate for colonoscopy preparation

BACKGROUND

Although polyethylene glycol lavage solutions are widely used for colonoscopy preparation, evidence suggests that sodium phosphate is better tolerated and has similar efficacy. The purpose of this study was to compare compliance with and efficacy of polyethylene glycol and sodium phosphate using meta-analysis and to compare the cost of colonoscopy with both methods.

METHODS

We used Medline to identify all randomized controlled trials comparing the two preparations. Study methods were evaluated, and quantitative data were abstracted independently, including inability to complete the preparation and preparation quality, rated as adequate or excellent. A random effects model was used to calculate the pooled relative risk. Direct costs and literature-based probability estimates were used to compare costs.

RESULTS

Among 1286 subjects from eight colonoscopist-blinded trials, the pooled relative risk of inability to complete the preparation was 0.23 (95% CI [0.18-0.28]) in favor of sodium phosphate. Although the best estimate of the relative risk for an adequate quality preparation revealed therapeutic equivalence (relative risk = 1.06: 95% CI [0.95-1.19]), an excellent quality preparation was more likely with sodium phosphate (relative risk = 1.72: 95% CI [1.16-2.53]). Assuming reexamination rates from published literature of 3% and 8% for sodium phosphate and polyethylene glycol, respectively, direct costs of colonic examination were $465 and $503. There were no clinically important adverse effects with either method.

CONCLUSION

The results suggest that sodium phosphate is as effective and less costly, with a more easily completed preparation, compared with polyethylene glycol and is the preferred method of preparation for colonoscopy for certain patient subgroups.

Spontaneous follicular exclusion of SHP1-deficient B cells is conditional on the presence of competitor wild-type B cells

Engagement of antigen receptors on mature B lymphocytes is known to block cell entry into lymphoid follicles and promote accumulation in T cell zones, yet the molecular basis for this change in cell distribution is not understood. Previous studies have shown that follicular exclusion requires a threshold level of antigen receptor engagement combined with occupancy of follicles by B cells without equivalent receptor engagement. The possibility has been raised that follicular composition affects B cell positioning by altering the amount of available antigen and the degree of receptor occupancy. Here we show that follicular composition affects migration of mature B cells under conditions that are independent of antigen receptor occupancy. B cells deficient in the negative regulatory protein tyrosine phosphatase, SHP1, which have elevated intracellular signaling by the B cell receptor, are shown to accumulate in the T zone in the absence of their specific antigen. Follicular exclusion of SHP1-deficient B cells was found to be conditional on the presence of excess B cells that lack elevated intracellular signaling, and was not due to a failure of SHP-1-deficient cells to mature and express the follicle-homing chemokine receptor Burkitt's lymphoma receptor 1. These findings strongly suggest that signals that are negatively regulated by SHP1 promote B cell localization in T cell zones by reducing competitiveness for follicular entry, and provide further evidence that follicular composition influences the positioning of antigen-engaged B cells.

Cloning and characterization of chicken Paraxis: a regulator of paraxial mesoderm development and somite formation

To investigate the molecular regulation of embryonic somite formation and development, we have cloned the full-length cDNA and characterized the embryonic expression profile of chicken Paraxis, a member of a novel family of basic helix-loop-helix (bHLH) proteins, which has been suggested to play a role in paraxial mesoderm development. Chicken Paraxis encodes a 1.35-kb mRNA and contains a 53-amino-acid residue bHLH domain, identical in sequence to that found in the mammalian Paraxis genes of mouse, hamster, and human. Northern analysis revealed significant Paraxis expression in the early embryo up to the 30- to 35-somite stage, declining from Incubation Day 4 on and becoming undetectable by Day 5. By whole-mount in situ hybridization, Paraxis expression is first seen distinctly in the emerging paraxial mesoderm of the primitive streak stage chick embryo. During gastrulation, Paraxis expression in the mesoderm defines bilaterally symmetric crescents located immediately rostral to Hensen's node and appears to pre-configure the emerging somitic mesoderm. During somite development, Paraxis expression is evident in the rostral segmental plate and the newly formed somites, although the level of expression clearly decreases in the more mature somites. By the 10-12th pair of somites, counting from the caudal end, Paraxis expression appears to be preferentially localized to the medial aspect of individual somites. Histological analysis showed that Paraxis expression is evenly distributed in the newly formed caudal epithelial somites, then localized to the medial portion of maturing somites, and preferentially localized in the dermomyotome of more rostral somites before diminishing to undetectable levels in the most cranial somites. The functional involvement of Paraxis in somite development was assessed by perturbing its expression in somitic stage chick embryos using a Paraxis-specific antisense oligonucleotide. Disruption of somite formation from the paraxial mesoderm was observed in 67% of the surviving topically treated embryos, whereas control embryos treated with sense or random sequence oligonucleotides did not show similar effects. In addition, direct injection of Paraxis-specific antisense oligonucleotide into the paraxial mesoderm produced discrete segmentation anomalies which correlated spatially with the site of injection. Whole-mount in situ hybridization revealed that the regions defective in somite formation displayed perturbed Paraxis expression and a reduction of Pax-1 expression, a marker for epithelial somites and sclerotome. Histological analysis indicated poor condensation and/or epithelization of the somitic mesoderm. Finally, embryos treated with valproic acid, a known teratogen which affects somite segmentation, showed perturbed Paraxis expression, suggesting that the mechanism of action of this teratogen involves a pathway(s) requiring Paraxis activity. These data provide evidence that Paraxis acts as an important regulator of paraxial mesoderm and somite development and functions in axial patterning of the chick embryo.

House dust mite allergens (Der p I and Der p V) within domestic environments of atopic and control children

We used allergen-specific ELISA to evaluate environmental distributions of house dust mite allergens (Der p I and Der p V) in the homes of 46 asthmatic, 20 atopic, and 26 nonatopic control children during the summer and winter. Geometric mean Der p I levels were approximately 10 times higher than geometric mean Der p V concentrations. The concentrations of Der p I and Der p V in winter were significantly higher than concentrations found in summer. In addition, we found no differences in Der p I concentrations among the three groups in summer; however, in winter, Der p I levels in the control group were significantly higher than levels in the homes of both asthmatic and atopic children. During the summer, concentrations of Der p V were lower in the control group, compared with the asthmatic group, but during the winter, concentrations in the control group were higher than levels found in either asthmatic or atopic children's homes. In this study, we did not establish an important relationship between mite allergen exposure and atopy/asthma.

Indoor pollution and sick building syndrome symptoms among workers in day-care centers

In this study, we investigated indoor air quality and symptoms of respiratory illness in 264 nursing workers at 28 day-care centers in Taipei. Geometric mean concentrations of indoor and outdoor bacteria were 735 colony-forming units in air (CFU/m3) and 384 CFU/m3, respectively. In addition, geometric mean concentrations of indoor and outdoor fungi were 1,212 CFU/m3 and 1,032 CFU/m3, respectively. Aspergillus, Cladosporium, and Penicillium-microfungi that occurred most commonly-were found indoors and outdoors. Geometric mean concentrations of house dust mite allergens, Der p I and Der p V, were 58 ng/g dust and 14 ng/g dust, respectively. In addition, the observed high prevalence of dampness or mold problems in the day-care centers indicated that dampness was very common in this subtropical region. We found a significant relationship between dampness and work-related sick building syndrome in the day-care-center workers. Furthermore, concentrations of fungi were lower in the day-care centers equipped with air conditioners/air cleaners than in centers that lacked such equipment. Also, Aspergillus was associated strongly with work-related sick building syndrome in the day-care-center workers.

Dampness and respiratory symptoms among workers in daycare centers in a subtropical climate

We evaluated the association between measures of dampness in daycare centers (N = 56) in the Taipei area and symptoms of respiratory illness in 612 employees. Dampness was found in 75.3% of the centers, visible mold in 25.8%, stuffy odor in 50.0%, water damage in 49.3%, and flooding in 57.2%. Furthermore, prevalence of sick building syndrome symptoms in the daycare workers was statistically significant among those who worked in centers that had mold or dampness. Also, the observed numerous incidences of dampness or mold in centers were very common in this subtropical region, and dampness was a strong predictor of sick building syndrome symptoms.

Chicken Pax-1 gene: structure and expression during embryonic somite development

Recent mouse genetic studies have implicated Pax-1, a paired-box-containing gene, in sclerotomal differentiation and vertebral body formation. To investigate Pax-1 function in somitic sclerotomal differentiation in the chick embryo, we have cloned the chicken Pax-1 gene, and its full length cDNA, and characterized its temporal and spatial expression pattern during somite development. Sequence analysis shows that chicken Pax-1 is highly homologous to murine and human Pax-1 genes with respect to the putative DNA-binding paired-box domain and the octapeptide domain. Northern analysis using probes derived from the paired-box domain and a unique non-paired box sequence of chicken Pax-1 detected 2-kb mRNA transcript. The expression profiles of Pax-1 were examined by in situ hybridization and Northern analysis. The first detectable expression of Pax-1 is seen in the most caudal epithelial somite. As the somite matures, Pax-1 expression takes on a medial distribution, thus corresponding to but preceding the emergence of the sclerotome. In the more mature, rostral somites (stage V and older), Pax-1 expression is found to be progressively localized first to the ventral-medial regions, and then to the caudal-ventral-medial quadrant of the mature somite. This pattern strongly supports the notion that Pax-1 expression is involved in somitogenesis and sclerotomal differentiation, and that it is subsequently a characteristic of the caudal half of the sclerotome, the presumptive precursor of vertebral cartilage. Northern analysis substantiated this expression profile and further revealed that the level of somitic Pax-1 expression increases as a function of embryonic development. Finally, we subjected chicken embryos to controlled heat shock treatment to perturb somite formation and segmentation. The pattern of Pax-1 expression in the anomalous somitic structures generated by controlled heat shock further supports a functional role for Pax-1 in somite development.

Passive mode locking of semiconductor lasers based on nonlinear directional coupling

We demonstrate numerically a novel passive mode-locking mechanism for semiconductor lasers based on nonlinear directional coupling. In a designed ring cavity a long pulse can be compressed in the bar port of the directional coupler as a result of linear coupling and gain saturation. Meanwhile, a pulse with a shorter pulse width and a higher pulse energy emerges from the cross port. Hence we can use the cross port as the output coupler of the laser system, leading to an output pulse energy that is greater than the intracavity pulse energy.

Lung cancer and smoking in Shanghai

A case-control study involving interviews with 733 male and 672 female incident lung cancer patients and 1495 population-based controls revealed that cigarette smoking is the dominant cause of lung cancer among men in urban Shanghai. All of the principal cell types were affected, with clear trends of rising risk with increasing intensity and duration of smoking. Far fewer women smoked cigarettes, but the overall risk patterns resembled those among males. Among women, however, smoking accounted for only about one-quarter of all lung cancers and less than 10% of lung adenocarcinomas. The findings lay to rest any doubts about the health hazards of smoking Chinese cigarettes, although smoking is not responsible for the high rates of adenocarcinoma reported among Chinese women.