Deterministic Dynamics in Neuronal Discharge from Pallidotomy Targets

The non-linear dynamic specificity of the firing pattern discharged from neurons of the internal globus pallidus (GPi) was investigated by recording their spontaneous firing using a microelectrode during posteroventral pallidotomy in eight patients with Parkinson's disease. Raw data from the cells were processed to extract spiking events (discharges above a selected threshold) and the interspike interval was measured. Using the unstable periodic orbits extraction method, significant period-1, −2 and −3 orbits were identified in burst firing discharged from the GPi cells in all eight patients, suggesting that deterministic dynamics exist in the timing of the discharges. As well as providing a useful peri-operative technique for locating posteroventral pallidotomy targets in Parkinson's disease, this method also provides a promising basis for investigating characteristic neuronal discharges in other regions of the brain and for various other neurological disorders.

The Nucleus Accumbens Core has a More Important Role in Resisting Reactivation of Extinguished Conditioned Place Preference in Morphine-addicted Rats

We investigated the roles of the core and shell subfields of the nucleus accumbens (NAc) in drug- or foot-shock-induced reactivation of extinguished conditioned place preference (CPP) in morphine-addicted rats. Rats were given electrolytic lesions to either the core or shell after CPP was established. After surgery, a reduction of CPP scores to morphine was observed in all groups. During the reacquisition of morphine-seeking behaviour, rats in the shell and sham lesion groups regained their CPP, while the CPP in core lesion rats remained severely impaired. Similarly, foot-shock-induced reactivation of CPP in the core lesion group was significantly lower than that of the shell and sham lesion groups, and there was no significant difference between these latter groups. Our results demonstrate that NAc core and shell lesions elicited dissociable effects on reactivation of extinguished CPP in rats, suggesting that the NAc core might play a more important role in resisting reactivation of extinguished CPP in morphine-addicted rats.

Nicotinamide adenine dinucleotide based therapeutics

Nicotinamide adenine dinucleotide (NAD), generally considered a key component involved in redox reactions, has been found to participate in an increasingly diverse range of cellular processes, including signal transduction, DNA repair, and post-translational protein modifications. In recent years, medicinal chemists have become interested in the therapeutic potential of molecules affecting interactions of NAD with NAD-dependent enzymes. Also, enzymes involved in de novo biosynthesis, salvage pathways, and down-stream utilization of NAD have been extensively investigated and implicated in a wide variety of diseases. These studies have bolstered NAD-based therapeutics as a new avenue for the discovery and development of novel treatments for medical conditions ranging from cancer to aging. Industrial and academic groups have produced structurally diverse molecules which target NAD metabolic pathways, with some candidates advancing into clinical trials. However, further intensive structural, biological, and medical studies are needed to facilitate the design and evaluation of new generations of NAD-based therapeutics. At this time, the field of NAD-therapeutics is most likely at a stage similar to that of the early successful development of protein kinase inhibitors, where analogs of ATP (a more widely utilized metabolite than NAD) began to show selectivity against target enzymes. This review focuses on key representative opportunities for research in this area, which extends beyond the scope of this article.

Predictors of outcome and treatment decisions of older patients with stage III non-small cell lung cancer

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Background: In treating Stage III non-small cell lung cancer in the elderly, oncologists often empirically adjust treatment without clear guidelines. Identifying patient characteristics that impact prognosis will aid in creating better treatment algorithms in this patient population. Methods: A retrospective analysis was done on older patients (age > 70) treated for Stage III NSCLC (excluding “wet” IIIB) at the H. Lee Moffitt Cancer. Cox multivariate analysis identified variables impacting progression free survival, overall survival, treatment chosen, treatment interruptions, and hospitalizations. Correlation and regression tree analysis (CART) was performed to create potential decision making models. Results: 213 patients were evaluable. Multivariate analysis identified ECOG performance status (hazard ratio = 1.52, p = 0.005) and nodal status (HR = 1.36, p = 0.001) as negatively associated with PFS while BMI (HR = 0.96, p = 0.02) was positively associated. ECOG performance status (HR = 2.26, p < 0.0001), nodal status (HR = 1.18, p = 0.08), and CIRS3 (having a comorbidity classified as severity 3; HR = 1.33, p = 0.02) were negatively associated with OS. BMI (HR = 0.95, p = 0.002) and CIRSmean (mean CIRS-G severity score; HR 0.61, p = 0.01) were positively associated with OS. These variables were also identified as the most significant splitters, along with smoking status and pulmonary function, in CART analyses. Trees using PFS and OS as outcomes were created with receiver operating curves (ROC) ranging from 0.64–0.75. A CART analysis targeting treatment modality chosen had ROCs ranging from 0.49–0.78. Conclusions: Our multivariate analysis found ECOG performance status, nodal status, and severe medical comorbidity as negatively associated with survival. Unexpectedly, BMI (at initial treatment), independent of weight loss, was found to be positively associated. Also, the splitter variables identified by CART analysis were very similar to the general multivariate model, but the weights differed in the various analyses and subgroups of patients. The CART analyses suggest that we can create decision making models with a range of applicability comparable to those commonly considered useful for clinical guidelines, i.e. about 60% of straightforward application.

No significant financial relationships to disclose.

Periprocedural complications associated with endovascular embolisation of intracranial ruptured aneurysms with matrix coils

INTRODUCTION

Matrix is a type of bioactive coil expected to produce healing of cerebral aneurysms. We reviewed periprocedural complications associated with endovascular embolisation of ruptured intracranial aneurysms with matrix coils and evaluated the effects of matrix coils.

METHODS

From October 2003 to September 2005, a total of 102 patients with 102 ruptured aneurysms and ten unruptured aneurysms underwent embolisations with matrix coils. We reviewed the medical records, radiographical studies and endovascular procedures to evaluate the morbidity and mortality related to ruptured aneurysm coiling.

RESULTS

16 complications (15.7 percent) occurred, of which 14 were in the anterior circulation and two in the posterior circulation. Complications included nine intraprocedural ruptures (8.8 percent), three thromboembolism (2.9 percent), one coil migration (1.0 percent) and three parent vessel occlusions (2.9 percent). Six complications had no neurological consequences, three were with transient deficits, six resulted in persistent neurological deficits, and one caused the patient to die. No complication was associated with balloon remodelling technique, and coil migration occurred during one of the neuroform-assisted embolisations. Procedural-related neurological morbidity and mortality for all 102 embolisations of ruptured aneurysms were 5.9 percent and 1.0 percent, respectively.

CONCLUSION

Endovascular treatment of ruptured intracranial aneurysms with matrix coils is as safe as with bare platinum coils. Matrix coil does not increase the risk of thromboembolism. However, we must be cautious when we embolise small aneurysms with matrix coils, especially when the aneurysms are less than 5 mm in diameter.

Multifunctional role of choline binding protein G in pneumococcal pathogenesis

Members of the choline binding protein (Cbp) family are noncovalently bound to phosphorylcholine residues on the surface of Streptococcus pneumoniae. It has been suggested that CbpG plays a role in adherence and increase virulence both at the mucosal surface and in the bloodstream, but the function of this protein has been unclear. A new sequence analysis indicated that CbpG is a possible member of the S1 family of multifunctional surface-associated serine proteases. Clinical isolates contained two alleles of cbpG, and one-third of the strains expressed a truncated protein lacking the C-terminal, cell wall-anchoring choline binding domain. CbpG on the surface of pneumococci (full length) or released into the supernatant (truncated) showed proteolytic activity for fibronectin and casein, as did CbpG expressed on lactobacilli or as a purified full-length or truncated recombinant protein. Recombinant CbpG (rCbpG)-coated beads adhered to eukaryotic cells, and TIGR4 mutants lacking CbpG or having a truncated CbpG protein showed decreased adherence in vitro and attenuation of disease in mouse challenge models of colonization, pneumonia, and bacteremia. Immunization with rCbpG was protective in an animal model of colonization and sepsis. We propose that CbpG is a multifunctional surface protein that in the cell-attached or secreted form cleaves host extracellular matrix and in the cell-attached form participates in bacterial adherence. This is the first example of distinct functions in virulence that are dependent on natural variation in expression of a choline binding domain.

Analysis of ADAMTS4 and MT4-MMP indicates that both are involved in aggrecanolysis in interleukin-1-treated bovine cartilage

OBJECTIVE

To investigate the mechanism of aggrecanolysis in interleukin-1 (IL-1)-treated cartilage tissue by examining the time course of aggrecan cleavages and the tissue and medium content of membrane type 4-matrix metalloproteinases (MT4-MMP) and a disintegrin and metalloproteinase with thrombospondin type I motifs (ADAMTS)4.

METHODS

Articular cartilage explants were harvested from newborn bovine femoropatellar groove. The effects of IL-1 treatment with or without aggrecanase blockade were investigated by Western analysis of aggrecan fragment generation, ADAMTS4 species (p68 and p53), and MT4-MMP, as well as by realtime PCR (polymerase chain reaction) for ADAMTS4 and 5. Aggrecanase was blocked with mannosamine (ManN), an inhibitor of glycosylphosphatidylinositol anchor synthesis, and esculetin (EST), an inhibitor of MMP-1, MMP-3, and MMP-13 gene expression.

RESULTS

IL-1 treatment caused a major increase in MT4-MMP abundance in the tissue and medium. ADAMTS4 (p68) was abundant in fresh cartilage and this was retained in the tissue in untreated cartilage. IL-1 treatment for 6 days caused a marked loss of p68 from the cartilage and the appearance of p53 in the medium. Addition of either 1.35 mM ManN or 31-500 microM EST blocked IL-1-mediated aggrecanolysis and this was accompanied by nearly complete inhibition of the MT4-MMP increase, the p68 loss and the formation of p53. IL-1 treatment increased mRNA abundance for ADAMTS4 ( approximately 3-fold) and ADAMTS5 ( approximately 10-fold) but this was not accompanied by a marked change in enzyme protein abundance.

CONCLUSION

These studies support a central role for MT4-MMP in IL-1-induced cartilage aggrecanolysis and are consistent with the identification of p68 as the aggrecanase that cleaves within the CS2 domain, and of p53 as the aggrecanase that generates G1-NITEGE. Since the induction by IL-1 was not accompanied by marked changes in total ADAMTS4 protein, but rather in partial conversion of p68 to p53 and release of both from the tissue, we conclude that aggrecanolysis in this model system results from MT4-MMP-mediated processing of a resident pool of ADAMTS4 and release of the p68 and p53 from their normal association with the cell surface.

Evaluation of toxicity from high-dose systemic administration of recombinant adenovirus vector in vector-naïve and pre-immunized mice

Toxicity associated with in vivo administration of adenovirus (Ad) vectors has been linked to activation of both innate and adaptive immune responses. Pre-existing immunity to the prevalent Ad serotypes, acquired by the majority of the human population as a result of natural infections, has the potential to modulate vector efficacy and safety. Previously, we evaluated some aspects of toxicity from systemic Ad vector in vector-naive and pre-immunized rhesus monkeys. In this report, we summarize data from several studies analyzing toxic effects from systemically administered E1/E3-deleted Ad vector in vector-naive and pre-immunized C57BL/6 mice. Our results indicate that pre-immunization can be associated with increased mortality shortly after systemic administration of Ad. Transient leukopenia and thrombocytopenia were observed early post vector infusion in both vector-naive and pre-immunized animals. Pre-exposure to the vector did not prevent induction of pro-inflammatory cytokines; however, pre-immunized mice showed less tissue toxicity. Growth of bone marrow myeloid and erythroid progenitors was transiently inhibited in pre-immunized animals, but only the myeloid progenitors were affected in vector-naive animals. In summary, pre-existing immunity to Ad vector substantially modifies host immune responses to systemic Ad vector.

The minimum number of clones necessary to sequence in order to obtain the maximum information about hepatitis C virus quasispecies: a comparison of subjects with and without liver cancer

Most studies of hepatitis C virus (HCV) quasispecies have reported the results of sequencing only three to five clones per sample. The possibility that sequencing so few clones might not provide a representative picture of the quasispecies present in a sample has never been evaluated. The present study was conducted to evaluate whether sequencing greater numbers of clones results in better information about the HCV quasispecies number and distribution, and to compare the HCV quasispecies in liver cancer cases and controls. RNA was extracted from serial serum samples from six subjects with HCV-associated liver cancer and 11 age- and sex-matched HCV-infected controls without liver cancer. The hypervariable region 1 (HVR1) of the HCV genome was amplified, cloned, and sequenced. For further studies of 12 serum samples from two liver cancer cases and two matched controls, successive groups of 10 additional clones were sequenced up to a total of 50 clones per serum sample. When only 10 clones were sequenced from each specimen, no consistent differences were seen between the number of HCV quasispecies in the six liver cancer cases and the 11 controls. However, sequencing 40 clones from each of 12 samples from two liver cancer cases and two controls revealed a greater number of quasispecies in liver cancer cases than in controls. Testing an additional 10 clones (50 clones per sample) did not significantly increase the number of quasispecies detected.

Plasminogen kringle 5 reduces vascular leakage in the retina in rat models of oxygen-induced retinopathy and diabetes

AIMS/HYPOTHESIS

Retinal vascular leakage is an early pathological feature in diabetic retinopathy and can lead to macular oedema and loss of vision. Previously we have shown that plasminogen kringle 5 (K5), an angiogenic inhibitor, inhibits retinal neovascularisation in the rat model of oxygen-induced retinopathy (OIR). The purpose of this study was to examine the effect of K5 on vascular leakage in the retina.

METHODS

Neonatal rats were exposed to hyperoxia to induce OIR. Diabetes was induced in adult rats by injecting streptozotocin. Vascular permeability was measured by Evans blue method. Expression of vascular endothelial growth factor (VEGF) was evaluated using immunohistochemistry and western blot analysis.

RESULTS

Rats with OIR and diabetes showed abnormal vascular hyperpermeability in the retina and iris. Intravitreal injection of K5, reduced vascular permeability in both animal models, but did not affect permeability in normal rats. K5 reduced vascular permeability at doses substantially lower than that required for inhibition of retinal neovascularisation. The K5-induced reduction in vascular permeability correlated with its down-regulation of VEGF expression in the retina. Moreover, K5 inhibited IGF-1-induced hyperpermeability, which is known to arise through up-regulation of endogenous VEGF expression. However, K5 had no effect on the hyperpermeability induced by injection of exogenous VEGF.

CONCLUSIONS/INTERPRETATION

Very low doses of K5 reduce pathological vascular leakage in the retina. K5 thus has therapeutic potential in the treatment of diabetic macular oedema. This effect can be ascribed, at least in part, to the down-regulation of endogenous VEGF expression.

High throughput creation of recombinant adenovirus vectors by direct cloning, green-white selection and I-Sce I-mediated rescue of circular adenovirus plasmids in 293 cells

Ability of replication-defective adenovirus vectors to achieve efficient gene transfer in most of the mammalian cell types makes them useful vehicles for many gene transfer applications, including their use in assessing gene function. High throughput creation of recombinant adenovirus becomes a critical path to the expanding utility of adenovirus vector technology. Here, we report a process in which recombinant adenovirus vectors are isolated as single molecular clones through a convenient direct cloning and green-white selection procedure, and directly transfected into 293 cells where virus is rescued through an enzymatic reaction mediated by an intron-encoding rare endonuclease I-Sce I. This process of enzymatic rescue of circular molecular clones was at least 10-fold more efficient than that using linearized clones for transfection. This method will facilitate a high throughput creation of vectors as required for screening gene function.

Kallikrein-binding protein inhibits retinal neovascularization and decreases vascular leakage

AIMS/HYPOTHESIS

Kallikrein-binding protein (KBP) is a serine proteinase inhibitor (serpin). It specifically binds to tissue kallikrein and inhibits kallikrein activity. Our study was designed to test its effects on retinal neovascularization and vascular permeability.

METHODS

Endothelial cell proliferation was determined by [(3)H] thymidine incorporation assay and apoptosis quantified by Annexin V staining and flow cytometry. Effect on retinal neovascularization was determined by fluorescein angiography and count of pre-retinal vascular cells in an oxygen-induced retinopathy (OIR) model. Vascular permeability was assayed by the Evans blue method. Vascular endothelial growth factor (VEGF) was measured by Western blot analysis and ELISA.

RESULTS

Kallikrein-binding protein specifically inhibited proliferation and induced apoptosis in retinal capillary endothelial cells. Intravitreal injection of KBP inhibited retinal neovascularization in an OIR model. Moreover, KBP decreased vascular leakage in the retina, iris and choroid in rats with OIR. Blockade of kinin receptors by specific antagonists showed significantly weaker inhibition of endothelial cells, when compared to that of KBP, suggesting that the anti-angiogenic activity of KBP is not through inhibiting kallikrein activity or kinin production. KBP competed with (125)I-VEGF for binding to endothelial cells and down-regulated VEGF production in endothelial cells and in the retina of the OIR rat model.

CONCLUSION/INTERPRETATION

Kallikrein-binding protein is a multi-functional serpin, and its vascular activities are independent of its interactions with the kallikrein-kinin system. Inhibition of VEGF binding to its receptors and down-regulation of VEGF expression could represent a mechanism for the vascular activities of KBP.

Testosterone and sexual experience alter levels of plasma membrane binding sites for progesterone in the male rat brain

Physiological levels of progesterone act in conjunction with androgens to facilitate copulatory behavior in male rats, mice, and lizards. Radiolabeled progesterone conjugated to bovine serum albumin measured specific binding sites in membrane fractions from male rats that were gonadectomized and testosterone treated, or remained gonadally intact, to determine the role of gonadal steroids on mPR binding. To determine whether behavioral experience could alter binding levels, males either remained sexually naïve or became sexually experienced. In sexually naïve males, the highest levels of specific binding occurred in the dorsal portions of the medial preoptic area, with only moderate levels of binding in ventral portions of the medial preoptic area and the dorsal and ventral medial hypothalamus. However, conjugated progesterone binding in these brain regions did not change as a function of testosterone or behavioral manipulations. In contrast, the amygdala responded to behavioral experience with significantly (4-fold) increased binding in gonadectomized, T-treated males with sexual experience. These data indicate that the neuronal plasticity for membrane-associated progesterone binding is regionally specific, being regulated by sexual experience following the reinstatement of testosterone levels, thus suggesting a functional role for plasma membrane activity of progesterone in male rat reproduction.

Novel PDGFbetaR antisense encapsulated in polymeric nanospheres for the treatment of restenosis

Nanospheres composed of the biocompatible and biodegradable polymer, poly-DL-lactide/glycolide and containing platelet-derived growth factor beta-receptor antisense (PDGFbetaR-AS) have been formulated and examined in vitro and in vivo in balloon-injured rat restenosis model. The nanospheres (approximately 300 nm) of homogenous size distribution exhibited high encapsulation efficiency (81%), and a sustained release of PDGFbetaR-AS (phosphorothioated). Cell internalization was visualized, and the inhibitory effect on SMC was observed. Partially phosphorothioated antisense sequences were found to be more specific than the fully phosphorothioated analogs. A significant antirestenotic effect of the naked AS sequence and the AS-NP (nanoparticles) was observed in the rat carotid in vivo model. The extent of mean neointimal formation 14 days after injection of AS-NP, measured as a percentage of luminal stenosis, was 32.21 +/- 4.75% in comparison to 54.89 +/- 8.84 and 53.84 +/- 5.58% in the blank-NP and SC-NP groups, respectively. It is concluded that PLGA nanospheres containing phosphorothioated oligodeoxynucleotide antisense could serve as an effective gene delivery systems for the treatment of restenosis.

High-throughput identification, database storage and analysis of SNPs in EST sequences

Single nucleotide polymorphisms (SNPs) are the most frequent form of DNA variation and disease-causing mutations in many genes. Due to their abundance and slow mutation rate within generations, they are thought to be the next generation of genetic markers that can be used in a myriad of important biological, genetic, pharmacological, and medical applications. There are several strategies both experimental, and in-silico for SNP discovery and mapping. Experimental SNP discovery consists of a number of labourious steps that make this process complex and expensive. In-silico discovery has been proposed as an alternative discovery method that makes use and takes advantage of large data sets with potential SNP information that have been generated with other purposes and have not been used as a SNP information source yet. However, in order to successfully apply the in-silico method to large data sets, the following challenges need to be addressed: First it is necessary to build an integrated SNP pipeline that handles data processing steps smoothly from the beginning (collecting sequence information) to end (SNPs in the database). Also, SNP detection tool parameters have to be optimized to satisfy specific goals of the project. Finally, SNP data could not be fully used until the in-silico method is validated experimentally. In this paper we present a design and implementation of an in-silico SNP detection software pipeline that exploits the existence of large EST (expressed sequence tag) data sets and effectively addresses the above challenges. First, the pipeline allows for smooth data transition between its different components by implementing data interfaces that translate the data formats of the different tools in the different stages. Second, we optimized PolyBayes parameters for SNP detection in maize EST. Finally, we implemented a user interface that along with the database structure created allows the scientist to perform preliminary analysis of the data and to perform basic statistics on the SNP data prior to experimental validation. The pipeline works with two different types of sequence assemblers (PHRAP (http://www.phrap.org/) and CAT from DoubleTwist (http://www.doubletwist.com/). It uses a Bayesian engine for SNP detection (PolyBayes), selects relevant polymorphism information which is then uploaded into a database. We detected 2439 SNPs and 822 insertion deletions (INDELs) with a PolyBayes probability higher than 0.99 on the public set of 68,000 maize ESTs. The user interface allowed us analyzing the polymorphism information right after discovery in several ways that allowed us to gain insight into the distribution and significance of the newly acquired data.

[Determination of flavonoids and quality evaluation of Chinese traditional drug "puhuang"]

This paper deals with the determination of flavonoids and quality evaluation of Chinese Typha. Four species, viz. Typha angustata, T. angustifolia, T. davidiana and T. latifolia and eight commercial samples of Chinese traditional drug "Puhuang" were collected. Five flavonoids in pollen, filaments, female flowers and leaves were determined by HPLC using mu-Bondapak C18 column, water--isopropanol--tetrahydrofuran = 83.5:14:2.5, as mokile phase and detected at 287 nm). The qualities of different Typha species and commercial "Puhuang" samples have been compared, and the criteria for their quality control were also discussed.