Orbital-dependent Representation of Correlation Energy Functional

Exchange-correlation energy functionals depending on the Kohn-Sham orbitals and eigenvalues resolve some of the well-known deficiencies of the local density and generalized gradient approximations. Such functionals can be derived in first-principles fashion by use of standard many-body techniques, if the Kohn-Sham Hamiltonian is utilized as non-interacting reference Hamiltonian. In this way one can establish an exact relation for the exchange-correlation functional, which opens several routes for the derivation of approximate functionals. Straightforward expansion in powers of the electron-electron coupling constant gives, to first order, the exact exchange of density functional theory and, to second order, a correlation functional which has the same structure as the second order Møller-Plesset term. This simplest first-principles correlation functional reproduces both the shell structure in the exact correlation potential and dispersion forces. On the other hand, it overestimates all correlation effects and is variationally instable for systems with a very small HOMO-LUMO gap. Both deficiences can be resolved by partial resummation of the Kohn-Sham perturbation expansion. In this contribution two such resummations are discussed, a minimum form designed to address the variational instability at no computational cost (based on the Epstein-Nesbet diagrams) and a more systematic variant (based on the ring diagrams).

Noise trauma impairs neurogenesis in the rat hippocampus

The hippocampus, a major site of neurogenesis in the adult brain, plays an important role in memory. Based on earlier observations where exposure to high-intensity noise not only caused hearing loss but also impaired memory function, it is conceivably that noise exposure may suppress hippocampal neurogenesis. To evaluate this possibility, nine rats were unilaterally exposed for 2 h to a high-intensity, narrow band of noise centered at 12 kHz at 126 dB SPL. The rats were also screened for noise-induced tinnitus, a potential stressor which may suppress neurogenesis. Five rats developed persistent tinnitus-like behavior while the other four rats showed no signs of tinnitus. Age-matched sham controls showed no signs of hearing loss or tinnitus. The inner ear and hippocampus were evaluated for sensory hair cell loss and neurogenesis 10 weeks post-exposure. All noise exposed rats showed severe loss of sensory hair cells in the noise-exposed ear, but essentially no damage in the unexposed ear. Frontal sections from the hippocampus were immunolabeled for doublecortin to identify neuronal precursor cells, or Ki67 to label proliferating cells. Noise-exposed rats showed a significant reduction of neuronal precursors and fewer dividing cells as compared to sham controls. However, we could not detect any difference between rats with behavioral evidence of tinnitus versus rats without tinnitus. These results show for the first time that high intensity noise exposure not only damages the cochlea but also causes a significant and persistent decrease in hippocampal neurogenesis that may contribute to functional deficits in memory.

Overexpression of type-A rice response regulators, OsRR3 and OsRR5, results in lower sensitivity to cytokinins

Response regulators are part of a two-component regulatory system. The type-A Arabidopsis response regulators act as negative regulators. To understand the function of type-A response regulators in the model monocot plant, rice (Japonica cultivar-group: Zhonghua11), we overexpressed two type-A OsRR genes, OsRR3 and OsRR5 (pACT1:OsRR3 and pACT1:OsRR5). We hoped to gain insight into their molecular function in cytokinin-signaling pathways. Both OsRR3 and OsRR5 overexpressors had longer roots and more lateral roots compared with Zhonghua11, when treated with exogenous cytokinin. Using callus formation and chlorophyll content assays, we found that Zhonghua11 was more sensitive to cytokinin compared with other cultivars of rice, expressing high transcript levels of OsRR3 and OsRR5. The expression of most type-A OsRR genes was repressed by OsRR3 and OsRR5 overexpression. However, semi-quantitative RT-PCR showed that three type-A OsRR genes showed increased expression. Our results suggest that both OsRR3 and OsRR5 mainly act as negative regulators of cytokinin signaling, as indicated by the reduced sensitivity of OsRR3 and OsRR5 overexpressors to exogenous cytokinins.

Induced NG2 expressing microglia in the facial motor nucleus after facial nerve axotomy

Chondroitin sulfate proteoglycan (NG2) expressing cells, ubiquitously distributed in the CNS respond to injured or diseased neurons; however, their behaviors toward injured neurons have remained to be fully explored. In the present study, along with astrocytic and microglial responses, NG2 expressing cells reacted swiftly and robustly in the facial motor nucleus (FMN) subjected to axotomy. With time, hypertrophic NG2 expressing cells gradually adhered to and enwrapped the axotomized motoneurons. Tight encapsulations around axotomized motoneurons were eventually formed at 7, 14, and 28 days after axotomy. NG2 positive processes appeared to interpose between synapsin-1 immunoreactive nerve terminals and surfaces of axotomized motoneurons. Double labeling results showed that NG2 expressing cells encapsulating axotomized facial motoneurons were mainly microglia marked by OX42 and lectin; only a few of them were positive to platelet-derived growth factor-alpha receptor and none of them positive to ED-1. No Rhodamine particle was detected in the FMN ipsilateral to axotomy after venous injection of the particles. The results suggest that activated microglia in lesioned FMN were induced to express NG2 molecules. It is concluded that axotomized FMN showed two types of NG2 expressing cells namely constitutive NG2 cells and induced-NG2 expressing microglia.

Initiating insulin therapy in elderly patients with Type 2 diabetes: efficacy and safety of lispro mix 25 vs. basal insulin combined with oral glucose-lowering agents

AIMS

To compare starter insulins in the elderly subgroup of the DURABLE trial 24-week initiation phase.

METHODS

In a post-hoc analysis of the > or = 65 years subgroup enrolled in the DURABLE trial, we compared the safety and efficacy of lispro mix 25 (LM25: lispro 25%/insulin lispro protamine suspension 75%), n = 258, vs. glargine, n = 222, added to oral glucose-lowering agents.

RESULTS

Baseline glycated hemoglobin (HbA(1c)) was similar (LM25 8.7 +/- 1.2, glargine 8.8 +/- 1.1%, P = 0.612). At 24-weeks, LM25 patients had lower HbA(1c) (7.0 +/- 0.9 vs. 7.3 +/- 0.9%, P < 0.001), greater HbA(1c) reduction (-1.7 +/- 1.2 vs. -1.5 +/- 1.1%, P < 0.001), and more patients reaching HbA(1c) < 7.0% (55.6 vs. 41.0%, P = 0.005). LM25 patients were on more insulin (0.40 +/- 0.19 vs. 0.33 +/- 0.19 u/kg/day, P < 0.001) and experienced more weight gain (3.6 +/- 3.6 vs. 1.8 +/- 3.2 kg, P < 0.001). Additionally, LM25-treated patients reported a higher mean overall hypoglycaemia rate than glargine patients (40.8 +/- 47.6 vs. 31.1 +/- 48.5 episodes/patient/year, P = 0.037), while nocturnal hypoglycaemia rates were similar. Over 24 weeks, incidence of severe hypoglycaemia was higher for LM25 (4.3% vs. 0.9%, P = 0.018); however, by 24-week endpoint incidence was similar (0.8% vs. 0.0%P = 0.125).

CONCLUSIONS

In this elderly subgroup post-hoc analysis, LM25 demonstrated a lower endpoint HbA(1c) and a higher % of patients reaching HbA(1c) target of < 7.0%, but with more weight gain and higher rates of hypoglycaemia compared to glargine.

Succesful [Successful] endovascular repair of an abdominal mycotic aneurysm. A case report

A 73-year-old man was admitted to the emergency department presenting with cramping pain in the left iliac fossa that had persisted for ten days, with diarrhoea and dysuria. A recent onset of high fever had urged him to the hospital. A routine blood sample showed a leukocytosis of 11.9 x 10(3)/mm(3) and an elevated CRP of 16 mg/dl. Haemocultures and a urine sample were taken. A colonoscopy and ultrasound showed no abnormalities. The urine culture contained salmonella enteritidis. On day 5 a CT scan of the abdomen was performed. This showed a saccular aneurysm of the abdominal aorta, approximately 2 cm in length, with clear signs of a contained rupture. An urgent EVAR procedure was performed. An Excluder bifurcation-endoprosthesis was placed under antibiotic coverage. Control CT scan showed a thrombosis of the aneurysm and a type II endoleakage. The endoleakage spontaneously resolved within 3 months. The patient was kept on antibiotics (levofloxacine) for 4 months. We suggest that the use of an endoprosthesis could be a good and safe alternative for the repair of infrarenal mycotic aorta aneurysm.

Gold nanoparticles as a contrast agent for in vivo tumor imaging with photoacoustic tomography

Photoacoustic tomography (PAT) is a rapidly emerging non-invasive imaging technology that integrates the merits of high optical contrast with high ultrasound resolution. The ability to quantitatively and non-invasively image nanoparticles has important implications for the development of nanoparticles as in vivo cancer diagnostic and therapeutic agents. In this study, the ability of systemically administered poly(ethylene glycol)-coated (PEGylated) gold nanoparticles as a contrast agent for in vivo tumor imaging with PAT has been evaluated. We demonstrate that gold nanoparticles (20 and 50 nm) have high photoacoustic contrast as compared to mouse tissue ex vivo. Gold nanoparticles can be visualized in mice in vivo following subcutaneous administration using PAT. Following intravenous administration of PEGylated gold nanoparticles to tumor-bearing mice, accumulation of gold nanoparticles in tumors can be effectively imaged with PAT. With gold nanoparticles as a contrast agent, PAT has important potential applications in the image guided therapy of superficial tumors such as breast cancer, melanoma and Merkel cell carcinoma.

SHARP-2 gene silencing by lentiviral-based short hairpin RNA interference prolonged rat kidney transplant recipients' survival time

Split- and hairy-related protein-2 (SHARP-2) controls the expression of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), which both play a key role in transplant rejection. This study was designed to investigate whether SHARP-2 short hairpin RNA interference (shRNAi) could prolong the survival of rat kidney transplant recipients. A lentiviral-based shRNAi construct, LV-SHARP-2iC, showed a SHARP-2 gene silencing efficiency of 84% in normal rat kidney cells. In activated T-cells, SHARP-2 gene silencing with the LV-SHARP-2iC construct resulted in 61% and 69% down-regulation of IL-2 and IFN-gamma, respectively, compared with a scramble control construct. When donor kidney was perfused with 5 x 10(7) transforming units of the LV-SHARP-2iC construct, the median survival time of the transplant recipients was prolonged by 4 - 5 days compared with control groups. In conclusion, recombinant lentiviral LV-SHARP-2iC construct effectively silenced SHARP-2 gene expression, which reduced IL-2 and IFN-gamma mRNA expression and prolonged rat kidney transplant recipients' survival.

Screening for fractions of Oxytropis falcata Bunge with antibacterial activity

Preliminary studies with the four extracts of Oxytropis falcate Bunge exhibited that the chloroform and ethyl acetate extracts showed stronger antibacterial activities against the nine tested Gram-positive and Gram-negative bacteria. The HPLC-scanned and bioassay-guided fractionation led to the isolation and identification of the main flavonoid compounds, i.e. rhamnocitrin, kaempferol, rhamnetin, 2',4'-dihydroxychalcone and 2',4',beta-trihydroxy-dihydrochalcon. Except 2',4',beta-trihydroxy-dihydrochalcon, four other compounds had good antibacterial activities. The minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of the four compounds ranged between 125 and 515 microg mL(-1). Staphylococcus aureus was the most susceptible to these compounds, with MIC and MBC values from 125 to 130 microg mL(-1). This is the first report of antibacterial activity in O. falcate Bunge. In this study, evidence to evaluate the biological functions of O. falcate Bunge is provided, which promote the rational use of this herb.