Transplantation of embryonic small hepatocytes induces regeneration of injured liver in adult rat

Small hepatocytes as hepatic stem cells or progenitors may be transplanted to treat several end-stage liver diseases. To identify the characteristics of epithelial cells enriched from fetal liver, we used immunocytochemistry and electron micrography. All cells in the colonies were immunocytochemically positive for alpha fetoprotein and cytokeratins (CK) 7, CK8, and CK18, which are markers of hepatic progenitor. Under transmission electron microscopy, we observed the cultured cells to show naive characteristics of stem cells and to be significantly distinct from mature hepatocytes. To identity whether these small hepatocytes were able to proliferate and differentiate into mature hepatocytes, we cultured them in vitro, and, through the portal vein, and transplanted elements whose membrane were stained with red fluorescence using PKH26 linker dye, into the livers of CCl(4)-treated rats that had been subjected to two-thirds partial hepatectomy. Significant liver regeneration was observed 30 days later in rats that did or did not receive the cells. The livers of hepatocytes recipients showed sharper edges and smoother surfaces than the control group. Diffused cells labeled with red fluorescence were observed in the portal area, with branch-like red fluorescence in regions near portal areas of some lobules, suggesting that these elements were involved in the repair of liver lobules and differentiation into mature hepatocytes. Our results revealed that small hepatocytes not only have characteristics of hepatic stem cells, but also may be a source of cellular transplantation to treat liver diseases.

Synphilin-1 exhibits trophic and protective effects against Rotenone toxicity

Synphilin-1 is a cytoplasmic protein with unclear function. Synphilin-1 has been identified as an interaction partner of alpha-synuclein. The interaction between synphilin-1 and alpha-synuclein has implications in Parkinson's disease. In this study, we stably overexpressed human synphilin-1 in mouse N1E-115 neuroblastoma cells. We found that overexpression of synphilin-1 shortened cell growth doubling time and increased neurite outgrowth. Knockdown of endogenous synphilin-1 caused neuronal toxicity and shortened neurite outgrowth. We further found that synphilin-1 increased activation of the extracellular signal-regulated kinases (ERK1/2) and mediated neurite outgrowth. Rotenone, mitochondrial complex I inhibitor, has been shown previously to induce dopaminergic neurodegeneration and Parkinsonism in rats and Drosophila. We found that Rotenone induced apoptotic cell death in N1E-115 cells via caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage. Overexpression of synphilin-1 significantly reduced Rotenone-induced cell death, caspase-3 activation and PARP cleavage. The results indicate that synphilin-1 displays trophic and protective effects in vitro, suggesting that synphilin-1 may play a protective role in Parkinson's disease (PD) pathogenesis and may lead to a potential therapeutic target for PD intervention.

Search for the standard model higgs Boson in the ZH-->nunubb channel in 5.2 fb{-1} of pp collisions at sqrt[s]=1.96 TeV

A search is performed for the standard model Higgs boson in 5.2 fb{-1} of pp collisions at sqrt[s]=1.96 TeV, collected with the D0 detector at the Fermilab Tevatron Collider. The final state considered is a pair of b jets and large missing transverse energy, as expected from pp-->ZH-->nunubb production. The search is also sensitive to the WH-->lnubb channel when the charged lepton is not identified. For a Higgs boson mass of 115 GeV, a limit is set at the 95% C.L. on the cross section multiplied by branching fraction for [pp-->(Z/W)H](H-->bb) that is a factor of 3.7 larger than the standard model value, consistent with the factor of 4.6 expected.

Search for a resonance decaying into WZ boson pairs in pp collisions

We present the first search for an electrically charged resonance W' decaying to a WZ boson pair using 4.1 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp collider. The WZ pairs are reconstructed through their decays into three charged leptons (l=e, mu). A total of 9 data events is observed in good agreement with the background prediction. We set 95% C.L. limits on the W'WZ coupling and on the W' production cross section multiplied by the branching fractions. We also exclude W' masses between 188 and 520 GeV within a simple extension of the standard model and set the most restrictive limits to date on low-scale technicolor models.

Search for Higgs boson production in dilepton and missing energy final states with 5.4 fb(-1) of pp collisions at square root(s) = 1.96 TeV

A search for the standard model Higgs boson is presented using events with two charged leptons and large missing transverse energy selected from 5.4 fb(-1) of integrated luminosity in pp collisions at square root(s) = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron collider. No significant excess of events above background predictions is found, and observed (expected) upper limits at 95% confidence level on the rate of Higgs boson production are derived that are a factor of 1.55 (1.36) above the predicted standard model cross section at m(H) = 165 GeV.

Combination of Tevatron searches for the standard model Higgs boson in the W+W- decay mode

We combine searches by the CDF and D0 Collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb(-1) of pp collisions at square root(s) = 1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard model Higgs boson in the mass range 162-166 GeV at the 95% C.L.

The clinical study of repairing cauda equina fibres with fibrin glue after lumbar fracture and dislocation

STUDY DESIGN

A retrospective study.

OBJECTIVES

To study the outcome of repair of cauda equina fibres with fibrin glue after lumbar fracture and/or dislocation.

METHODS

Seven acute cases and one chronic case of L2 or L3 fracture and/or dislocation complicated with complete cauda equina injury were selected. Sural nerve or ventral roots of injured cauda equina were chosen to repair the motor cauda equina fibres with fibrin glue after open reduction and internal fixation of the unstable vertebrae. The functional recovery after surgery was observed.

RESULTS

Recovery of the strength of thigh muscles (iliopsoas, quadriceps femoris, gluteus maximus, adductors) was observed in all seven acutely injured patients (t=3.74, P<0.05), but not in the chronic one. Neither recovery of leg muscles nor sensation of the lower extremities was observed in any case.

CONCLUSIONS

The cauda equina ventral roots injured after lumbar fracture and/or dislocation can be repaired with fibrin glue and motor recovery is expected.

Radiation dose to the lens using different temporal bone CT scanning protocols

BACKGROUND AND PURPOSE

Temporal bone CT is performed frequently in clinical practice. At the same time, the eye lens are exposed to ionizing radiation without any useful diagnostic information delivered. Our aim was to investigate the radiation dose to the lens of the eye by using temporal bone CT scanning with different protocols.

MATERIALS AND METHODS

Direct axial and coronal CT by using a conventional sequential scanning mode (140 kV, 220 mAs/section, 1.25-mm thickness, 1.25-mm increment, 16 x 0.625 mm collimation, the glabellomeatal line as a scanning baseline), a routine helical scanning mode (140 kV, 220 mAs/section, 0.315 pitch, 0.67-mm thickness, 0.33-mm increment, 16 x 0.625 collimation, the orbitomeatal line as a scanning baseline), and a modified helical scanning mode (acanthiomeatal line as a scanning baseline; other parameters, same as above) was performed on an exsomatized cadaveric head. CTDI(vol) and DLP were recorded for each scanning mode, and effective doses were calculated. Organ doses for the lens were measured with TLDs.

RESULTS

When the sequential scanning mode was used, the gross effective dose was 1.21 mSv and the organ dose to the lens was 50.96 and 1.73 mGy, respectively, for direct axial and coronal imaging. The effective dose was 0.803 mSv in routine helical scanning, while the lens dose was 40.17 mGy. With the modified helical scanning mode, the effective dose was as same as that for the routine helical scanning, but the lens dose was reduced significantly to 10.33 mGy.

CONCLUSIONS

The effective doses resulting from sequential axial and coronal scanning were 1.51 times higher than the dose from helical scanning, and the lens dose was 1.31 times higher. With the modified helical scanning mode, thinner section images could be used to reformat axial, coronal, and sagittal images with a further 74.3% reduction in lens dose beyond that achieved with the conventional helical protocol.

Pharmacological characterization of cis-nitromethylene neonicotinoids in relation to imidacloprid binding sites in the brown planthopper, Nilaparvata lugens

Neonicotinoid insecticides, such as imidacloprid, are selective agonists of the insect nicotinic acetylcholine receptors (nAChRs) and extensively used in areas of crop protection and animal health to control a variety of insect pest species. Here we describe that two cis-nitromethylene neonicotinoids (IPPA152002 and IPPA152004), recently synthesized in our laboratory, discriminated between the high and low affinity imidacloprid binding sites in the brown planthopper, Nilaparvata lugens, a major insect pest of rice crops in many parts of Asia. [(3)H]imidacloprid has two binding sites with different affinities (Kd value of 0.0035 +/- 0.0006 nM for the high-affinity site and 1.47 +/- 0.22 nM for the low-affinity site). Although the cis-nitromethylene neonicotinoids showed low displacement ability (Ki values of 0.15 +/- 0.03 microM and 0.42 +/- 0.07 microM for IPPA152002 and IPPA152004, respectively) against [(3)H]imidacloprid binding, low concentrations (0.01 microM) of IPPA152002 completely inhibited [(3)H]imidacloprid binding at its high-affinity site. In Xenopus oocytes co-injected with cRNA encoding Nlalpha1 and rat beta2 subunits, obvious inward currents were detected in response to applications of IPPA152002 and IPPA152004, although the agonist potency is reduced to that of imidacloprid. The previously identified Y151S mutation in Nlalpha1 showed significant effects on the agonist potency of IPPA152002 and IPPA152004, such as a 75.8% and 70.6% reduction in Imax, and a 2.4- and 2.1-fold increase in EC(50). This data clearly shows that the two newly described cis-nitromethylene neonicotinoids act on insect nAChRs and like imidacloprid, discriminated between high and low affinity binding sites in N. lugens native nAChRs. These compounds may be useful tools to further elucidate the pharmacology and nature of neonicotinoid binding sites.

An experimental study of acute radiation-induced cognitive dysfunction in a young rat model

BACKGROUND AND PURPOSE

Radiation-induced cognitive dysfunction is a common and serious clinical complication after radiation therapy for a brain tumor, but the knowledge of its mechanism is poorly understood. The purpose of this study was to establish a young rat model for acute radiation-induced cognitive dysfunction and associated BBB damage, as well as histopathologic changes.

MATERIALS AND METHODS

Young male rats were randomized into 4 groups to receive irradiation treatments at 300 cGy/min with doses of 0 (sham), 10, 20, and 40 Gy, respectively. Each treatment group was further randomized into 4 subgroups for following up cognitive tests and assessment of their BBB integrity and potential histopathologic changes at 0, 7, 20, and 60 days.

RESULTS

We found that irradiation at 10 Gy failed to induce any significant effects. Irradiation at 20 Gy resulted in a transient impairment of the cognitive functions at 7 and 20 days and returned to normal at 60 days. Irradiation at 40 Gy caused the severest cognitive impairment, which peaked at 7 days, and lasted for at least 60 days. The impaired cognition in both the 20-Gy and 40-Gy-irradiated rats was more or less accompanied with increased brain water content and deteriorated BBB function, though mild histopathologic alternations were only noticed in the 40-Gy-irradiated rats at 20 days.

CONCLUSION

A single-dose exposure at 20 to 40 Gy is sufficient to induce acute brain injury at both cognitive and pathologic levels in young male rats. In addition, morphologic outcomes may not be sensitive enough to reveal all of the pathologic changes, whereas BBB disruption may be an earlier and more sensitive index for acute RE. Therefore, the present model is useful for basic and therapeutic studies of acute RE.

The effectiveness and cost-effectiveness of cochlear implants for severe to profound deafness in children and adults: a systematic review and economic model

OBJECTIVES

To investigate whether it is clinically effective and cost-effective to provide (i) a unilateral cochlear implant for severely to profoundly deaf people (using or not using hearing aids), and (ii) a bilateral cochlear implant for severely to profoundly deaf people with a single cochlear implant (unilateral or unilateral plus hearing aid).

DATA SOURCES

Main electronic databases [MEDLINE; EMBASE; Cochrane Database of Systematic Reviews; CENTRAL; NHS EED; DARE; HTA (NHS-CRD); EconLit; National Research Register; and ClinicalTrials.gov] searched in October 2006, updated July 2007.

REVIEW METHODS

A systematic review of the literature was undertaken according to standard methods. A state-transition (Markov) model of the main care pathways deaf people might follow and the main complications and device failures was developed.

RESULTS

The clinical effectiveness review included 33 papers, of which only two were RCTs. They used 62 different outcome measures and overall were of moderate to poor quality. All studies in children comparing one cochlear implant with non-technological support or an acoustic hearing aid reported gains on all outcome measures, some demonstrating greater gain from earlier implantation. The strongest evidence for an advantage from bilateral over unilateral implantation was for understanding speech in noisy conditions (mean improvement 13.2%, p < 0.0001); those receiving their second implant earlier made greater gains. Comparison of bilateral with unilateral cochlear implants plus an acoustic hearing aid was compromised by small sample sizes and poor reporting, but benefits were seen with bilateral implants. Cochlear implants improved children's quality of life, and those who were implanted before attending school were more likely to do well academically and attend mainstream education than those implanted later. In adults, there was a greater benefit from cochlear implants than from non-technological support in terms of speech perception. Increased age at implantation may reduce effectiveness and there is a negative correlation between duration of deafness and effectiveness. Speech perception measures all showed benefits for cochlear implants over acoustic hearing aids [e.g. mean increase in score of 37 points in noisy conditions (p < 0.001) with BKB sentences]; however, prelingually deafened adults benefited less than those postlingually deafened (mean change scores 20% versus 62%). For unilateral versus bilateral implantation, benefits in speech perception were significant in noisy conditions on all measures [e.g. 76% for HINT sentences (p < 0.0001)]. Quality of life measured with generic and disease-specific instruments or by interview mostly showed significant gains or positive trends from using cochlear implants. The Markov model base-case analysis estimated that, for prelingually profoundly deaf children, the incremental cost-effectiveness ratio (ICER) for unilateral implantation compared with no implantation was 13,413 pounds per quality-adjusted life-year (QALY). Assuming the utility gain for bilateral implantation is the same for adults and children, the ICERs for simultaneous and sequential bilateral implantation versus unilateral implantation were 40,410 pounds and 54,098 pounds per QALY respectively. For postlingually sensorineurally profoundly deaf adults, the corresponding ICERs were 14,163 pounds, 49,559 pounds and 60,301 pounds per QALY respectively. Probabilistic threshold analyses suggest that unilateral implants are highly likely to be cost-effective for adults and children at willingness to pay thresholds of 20,000 pounds or 30,000 pounds per QALY. There are likely to be overall additional benefits from bilateral implantation, enabling children and adults to hold conversations more easily in social situations.

CONCLUSIONS

Unilateral cochlear implantation is safe and effective for adults and children and likely to be cost-effective in profoundly deaf adults and profoundly and prelingually deaf children. However, decisions on the cost-effectiveness of bilateral cochlear implants should take into account the high degree of uncertainty within the model regarding the probable utility gain.

Charging effect of aluminum nitride thin films containing Al nanocrystals

In this work, the Al-rich AIN thin film is deposited on Si substrate by radio frequency (RF) sputtering to form a metal-insulator-semiconductor (MIS) structure. Al nanocrystals (nc-Al) are formed and embedded in the AIN thin film. Charge trapping/detrapping in the nc-Al leads to a shift in the flat-band voltage (VFB) of the MIS structure. The charge storage ability of the AIN thin films containing Al nanocrystals provides the possibility of memory applications. On the other hand, charge trapping in nc-Al reduces the current conduction because of the breaking of some tunneling paths due to Coulomb blockade effect and the current conduction evolves with a trend towards one-dimensional transport.

Direct measurement of the W boson width

We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.

Protective effect of N-acetylcysteine on experimental chronic cadmium nephrotoxicity in immature female rats

In the present study, female Sprague-Dawley rats received CdCl(2) (50 mg/L through drinking water) and/or N-acetylcysteine (NAC, 120 mg/kg/day, orally) to investigate the protective effect of NAC on Cd-induced renal damage. Renal toxicity was evaluated by measuring the contents of total protein, beta(2)-microglobulin, and alpha(1)-microglobulin in the urine and urinary enzyme markers of tubular necrosis, as well as levels of serum urea nitrogen and serum creatinine. Activities of antioxidant enzymes and contents of glutathione, malondialdehyde, and trace elements in the kidney were also measured. Animals that received both Cd and NAC showed a better renal function than those receiving Cd alone. In addition, NAC significantly reduced the levels of lipid peroxidation (LPO) in the kidney of cadmium-treated rats. The enzymic and nonenzymatic antioxidants levels are not restored, but their further decrease is prevented by NAC. Also NAC administration does not modify the urinary excretion of cadmium or contents of cadmium in the serum and kidney. In conclusion, NAC exerts its protective effect by decreased LPO and improving antioxidants status to prevent renal tubular damage induced by chronic Cd administration, most probably through its antioxidant properties.

Measurement of dijet angular distributions at square root(s) = 1.96 TeV and searches for quark compositeness and extra spatial dimensions

We present the first measurement of dijet angular distributions in pp collisions at square root(s) = 1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of 0.7 fb(-1) collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV(-1) scale extra dimensions. For all models considered, we set the most stringent direct limits to date.