Strong orbital-dependent d-band hybridization and Fermi-surface reconstruction in metallic Ca2-xSrxRuO4

We study the effects of RuO6 rotation on Ru 4d band structures in metallic Ca2-xSrxRuO4 (0.5 < or = x < or = 2) by first-principles electronic structure calculations. We show that the RuO6 rotation leads to the strong hybridization between dxy and dx2-y2 bands, resulting in orbital-dependent changes in the band structure. The dxy band near the Fermi level is significantly modified and thereby a severely reconstructed Fermi surface with nested sections appears at x=0.5. In contrast, the dyz and dzx bands are found to be insensitive to the rotational distortions induced by the Ca substitution. Our results imply that the progressive changes in the magnetic, optical, and thermal properties of Ca2-xSrxRuO4 are associated with the dxy band.

High throughput crystallography of TB drug targets

Tuberculosis (TB) infects one-third of the world population. Despite 50 years of available drug treatments, TB continues to increase at a significant rate. The failure to control TB stems in part from the expense of delivering treatment to infected individuals and from complex treatment regimens. Incomplete treatment has fueled the emergence of multi-drug resistant (MDR) strains of Mycobacterium tuberculosis (Mtb). Reducing non-compliance by reducing the duration of chemotherapy will have a great impact on TB control. The development of new drugs that either kill persisting organisms, inhibit bacilli from entering the persistent phase, or convert the persistent bacilli into actively growing cells susceptible to our current drugs will have a positive effect. We are taking a multidisciplinary approach that will identify and characterize new drug targets that are essential for persistent Mtb. Targets are exposed to a battery of analyses including microarray experiments, bioinformatics, and genetic techniques to prioritize potential drug targets from Mtb for structural analysis. Our core structural genomics pipeline works with the individual laboratories to produce diffraction quality crystals of targeted proteins, and structural analysis will be completed by the individual laboratories. We also have capabilities for functional analysis and the virtual ligand screening to identify novel inhibitors for target validation. Our overarching goals are to increase the knowledge of Mtb pathogenesis using the TB research community to drive structural genomics, particularly related to persistence, develop a central repository for TB research reagents, and discover chemical inhibitors of drug targets for future development of lead compounds.

Optimized THP-1 differentiation is required for the detection of responses to weak stimuli

OBJECTIVES

The differentiation of THP-1 monocytes into macrophages is mainly conducted at a phorbol 12-myristate 13-acetate (PMA) concentration of 10-400 ng/ml. However, this concentration might be high enough to upregulate the expressions of some genes in differentiated macrophages, which could overwhelm gene expression increases induced by other stimuli. The present study was performed to optimize the PMA concentration required to differentiate monocytes whilst minimizing gene upregulation.

METHODS

THP-1 cells were treated with 2.5-100 ng/ml PMA and analyzed for the extent of cell adherence, the surface marker of macrophages, and stable differentiation without undesirable gene upregulation. The stably differentiated THP-1 cells at the minimum PMA concentration were treated with 10 ng/ml LPS or 125 nM amyloid beta (Abeta(1-42)).

RESULTS

The treatment of THP-1 with 5 ng/ml PMA was found to be sufficient to induce stable differentiation without undesirable gene upregulation. These macrophages differentiated at 5 ng/ml responded well to secondary weak stimuli like 10 ng/ml LPS or 125 nM of amyloid beta (Abeta(1-42)).

CONCLUSIONS

This finding suggests that THP-1 cells are well differentiated by 5 ng/ml PMA, and that the resulting differentiated macrophages respond well to secondary weak stimuli without being overwhelmed by undesirable gene upregulation induced by PMA.

Removal of the laryngeal tube in children: anaesthetized compared with awake

BACKGROUND

Laryngeal tube (LT) is a useful airway device in children, but there is no objective evidence that removal of LT in awake state is better than in anaesthetized state. So, we compared the incidence of respiratory adverse events after the removal of LT, either under anaesthesia or on awakening.

METHODS

Seventy healthy children between 1 and 12 yr of age were enrolled in this study. Anaesthesia was induced and maintained with sevoflurane. After induction of anaesthesia, patients were randomized into two groups: removal of LT in anaesthetized state (Group A: 2% sevoflurane) and in awake state (Group B). During and within 1 min of the removal of LT, airway complications such as upper airway obstruction, cough, vomiting, teeth clenching, hypersalivation, desaturation <90%, and laryngospasm were recorded.

RESULTS

Cough (37.1 vs 2.9%), hypersalivation (28.6 vs 5.7%), desaturation (20 vs 0%), and LT dislocation during emergence relating to the patient's movement (26.5 vs 0%) occurred more frequently in Group B (P < 0.05). Upper airway obstruction occurred more frequently (68.6 vs 31.4%) in Group A, and it was easily resolved by chin or jaw lifting.

CONCLUSION

LT removal in anaesthetized state reduced cough, hypersalivation, and prevented tube displacement and hypoxia. Upper airway obstruction in the anaesthetized state should be predicted and managed with chin or jaw lifting.

Reverse transcription-polymerase chain reaction and western blotting analysis for detection of p63 isoforms in uterine cervical cancers

The aim of this study was to investigate the role of TAp63 and DeltaNp63 isoforms in uterine cervical cancers. The messenger RNA (mRNA) and protein expressions of TA and DeltaN forms as well as alpha, beta, and gamma isoforms of p63 were studied in seven SiHa, ME-180, SNU17, SNU902, SNU1160, SNU703, and SNU1299 human papillomavirus (HPV)-positive uterine cervical squamous cell carcinoma (SCC) cell lines, one HT3 HPV-negative SCC cell line, and one HeLa adenocarcinoma cell line using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Fresh nonneoplastic and neoplastic tissues of uterine cervical and endometrial cancers were also studied. RT-PCR for TA and DeltaN form and three isoforms of p63 showed positive bands for both TA and DeltaN forms and for all three isoforms in cervical cancer cell lines but weak band for alpha isoform in HPV-negative HT3 SCC cell line and no band for beta isoform in HeLa adenocarcinoma cell line. RT-PCR for TA and DeltaN and three isoforms of p63 mRNA in tissue samples showed positive bands in almost all samples, except for gamma isoform, the expression was weak or absent in nonneoplastic tissues compared with neoplastic tissues. In western blotting, cancer cell lines and both nonneoplastic and neoplastic tissue samples showed expression of TA and DeltaN, and gamma isoform but beta isoform expression with or without alpha isoform was only found in cancer cell lines and neoplastic tissues. beta isoform, possibly of DeltaNp63, may be considered as an important isoform in uterine cervical squamous cell carcinogenesis.

A comparison of oral health related quality of life between complete and partial removable denture-wearing older adults in Korea

The purpose of this study was to compare the oral health related quality of life (OHRQoL) between older Korean adults with complete and partial removable dentures using oral health impact profile (OHIP). A pool of 4250 Korean older adults was identified by random stratification by area from the sample cohort of Korean National Survey of Oral Health in the year of 2000. Out of the potential pool, 445 subjects with removable partial dentures (RPDs) or complete dentures (CDs) agreed to be interviewed by telephone. Each question in the survey was about how frequently each event was experienced during the past 12 months. To analyse the association between OHIP scores and removable denture status, bivariable analysis and multiple linear regression analysis were used. RPD users showed higher scores on eight items than CD users. They were 'breath stale', 'food catching', 'sensitive teeth', 'toothache', 'tense', 'unable to brush teeth', 'less tolerant to family members' and 'irritable with others'. RPD users might be associated with higher scores of functional limitation, physical pain and psychological discomfort than CD users. RPD users had slight tendency to be associated with higher OHIP-49 score than CD users, but it was not statistically significant. The findings of the present study confirm that there is no general OHRQoL difference between RPD and CD users. But in the items and subscales of OHIP, RPD users might experience more impaired OHRQoL than CD users.

Development and evaluation of triplex PCR for direct detection of mycobacteria in respiratory specimens

AIMS

To develop a method for the simultaneous detection of Mycobacterium tuberculosis, Mycobacterium avium-intracellularecomplex (MAC), and other mycobacteria in clinical specimens using triplex PCR.

METHODS AND RESULTS

The target of amplification was the internal transcribed spacer region between the l6S and 23S rDNA genes. Twenty-two mycobacterial type strains, 118 M. tuberculosis, 87 other mycobacteria, 75 nonmycobacterial pathogens, 115 respiratory specimens from confirmed cases of tuberculous or other mycobacterial diseases, and sputa from 50 patients with nonmycobacterial respiratory diseases were tested. In M. tuberculosis, 322 bp pan-mycobacterial and 133 bp species-specific bands were observed. In MAC, the respective bands were 322 and 84 bp. The other mycobacteria showed single pan-mycobacterial bands of approx. 300-350 bp. Nonspecific amplicons were not found in any of the nonmycobacterial pathogens. In the tuberculosis specimens, 96.4% of smear-positive specimens and 70.2% of smear-negative specimens showed positive reactions. Specimens from two patients with MAC infection were MAC positive. Only 1 of 50 specimens from nonmycobacterial diseases was positive (2.0%).

CONCLUSION, SIGNIFICANCE AND IMPACT OF THE STUDY

Triplex PCR enables accurate and rapid diagnosis of tuberculosis and probably is useful for the detection of MAC and other mycobacteria in respiratory specimens.

Alfentanil attenuates phenylephrine-induced contraction in rat aorta

BACKGROUND AND OBJECTIVES

Alfentanil was reported to relax the rat aorta by direct action on the vascular smooth muscle. The aims of this in vitro study were to examine the effect of alfentanil on phenylephrine-induced contractions in the rat aorta and to determine the cellular mechanism associated with this process.

METHODS

Endothelium-denuded aortic rings were suspended in order to record isometric tension. In the rings with or without 10(-6) mol naloxone or 10(-5) mol verapamil, the concentration-response curves for phenylephrine and potassium chloride were generated in the presence or absence of alfentanil (10(-6), 5 x 10(-5), 10(-4) mol). In the rings exposed to a calcium-free isotonic depolarizing solution, the contractile response induced by the addition of calcium was assessed in the presence or absence of alfentanil (5 x 10(-5), 10(-4) mol).

RESULTS

Alfentanil (5 x 10(-5), 10(-4) mol) attenuated (P < 0.05) the phenylephrine-induced contraction in the ring with or without 10(-6) mol naloxone but had no effect on the phenylephrine-induced contraction in the rings pretreated with verapamil. Alfentanil (5 x 10(-5), 10(-4) mol) produced a significant rightward shift (P < 0.01) in the potassium chloride dose-response curve, and attenuated the contractile response (P < 0.001) induced by calcium in the calcium-free isotonic depolarizing solution in a dose-dependent manner.

CONCLUSIONS

A supraclinical dose of alfentanil attenuates the phenylephrine-induced contraction via an inhibitory effect on calcium influx by blocking the l-type calcium channels in the rat aortic vascular smooth muscle.

Fentanyl reduces desflurane-induced airway irritability following thiopental administration in children

BACKGROUND

Airway irritation is a major drawback of desflurane anesthesia. This study was designed to evaluate the effect of intravenous fentanyl given before thiopental induction on airway irritation caused by a stepwise increase in desflurane in children.

METHODS

Eighty children (2-8 years) were enrolled in a randomized, double-blind study. Forty received saline and 40 received 2 microg/kg of fentanyl intravenously; this was followed by thiopental sodium 5 mg/kg in both groups. Patients were assistant-ventilated with desflurane 1%, which was then increased by 1% every six breaths up to 10%. During this period, cough, secretion, excitation and apnea were graded and the desflurane concentration at which airway irritation symptoms first occurred was recorded. The results were analyzed using Pearson's chi-squared test.

RESULTS

The incidence of typical airway irritation events was lower with fentanyl than with saline (cough, 2.5% vs. 42.5%; secretion, 27.5% vs. 82.5%; excitation, 10% vs. 82.5%; apnea, 20% vs. 65%; P < 0.05). The mean expired desflurane concentration at which the first airway irritation symptom occurred was greater with fentanyl than with saline (7.3% vs. 5.5%, P < 0.05).

CONCLUSIONS

Intravenous fentanyl in children reduces airway complications caused by desflurane.

Missing xy-band Fermi surface in 4d transition-metal oxide Sr2RhO4: effect of the octahedra rotation on the electronic structure

Electronic structures of the 4d transition-metal oxide compound Sr2RhO4 are investigated by angle-resolved photoemission spectroscopy and density-functional electronic structure calculations. In the measured Fermi surfaces (FS) of Sr2RhO4, the xy-band FS sheet expected from the well-established results of the FS of Sr2RuO4 is missing, the volume of which should be different only by one additional electron for Sr2RhO4. The apparent contradiction is resolved by a careful analysis of the band structure where the rotation of octahedra results in the hybridization of e(g) and t(2g) states and thus plays a key role in the determination of the electronic structure near EF. The modification of the FS structure due to the distorted lattice is related to the charge transfer among the orbital states and suggested to be relevant to the metal-insulator transition in Ca(2-x)Sr(x)RuO4.