A small molecule inhibitor of the Wnt antagonist secreted frizzled-related protein-1 stimulates bone formation

Canonical Wnt signaling has been demonstrated to increase bone formation, and Wnt pathway components are being pursued as potential drug targets for osteoporosis and other metabolic bone diseases. Deletion of the Wnt antagonist secreted frizzled-related protein (sFRP)-1 in mice activates canonical signaling in bone and increases trabecular bone formation in aged animals. We have developed small molecules that bind to and inhibit sFRP-1 in vitro and demonstrate robust anabolic activity in an ex vivo organ culture assay. A library of over 440,000 drug-like compounds was screened for inhibitors of human sFRP-1 using a cell-based functional assay that measured activation of canonical Wnt signaling with an optimized T-cell factor (TCF)-luciferase reporter gene assay. One of the hits in this screen, a diarylsulfone sulfonamide, bound to sFRP-1 with a K_D of 0.35 μM in a tryptophan fluorescence quenching assay. This compound also selectively inhibited sFRP-1 with an EC₅₀ of 3.9 μM in the cell-based functional assay. Optimization of this high throughput screening hit for binding and functional potency as well as metabolic stability and other pharmaceutical properties led to improved lead compounds. One of these leads (WAY-316606) bound to sFRP-1 with a K_D of 0.08 μM and inhibited it with an EC₅₀ of 0.65 μM. Moreover, this compound increased total bone area in a murine calvarial organ culture assay at concentrations as low as 0.0001 μM. This work demonstrates the feasibility of developing small molecules that inhibit sFRP-1 and stimulate canonical Wnt signaling to increase bone formation.     

Long-term results show triple stapling facilitates safe low colorectal and coloanal anastomosis and is associated with low rates of local recurrence after anterior resection for rectal cancer

BACKGROUND: During low anterior resection (AR), placement of a staple line distal to an occlusion clamp is often difficult due to the confines of a narrow bony pelvis. This study reviewed the results of AR with a technique in which a linear staple line is fired below the tumour as an oncologically safe occlusion clamp. METHODS: Between 1995 and 2000, a total of 174 patients were operated for rectal cancer, and 153 of these patients had AR. Triple stapling (TS) was used to place a line of staples that occluded the fully mobilised rectum below a tumour. After rectal washout, a further linear stapler was applied below the first, and the rectum was divided prior to a standard circular stapled anastomosis. RESULTS: TS was performed in 127 (83%) of 153 patients undergoing AR, and 9 TS patients developed leaks (7%). In the whole series of 174 cases, 9 patients had local recurrence (5%), but the local recurrence rate for procedures classified as 'locally curative' was 2%. CONCLUSIONS: Triple stapling reliably occludes the rectum allowing for distal rectal washout. It eliminates clamp slippage and faecal spillage and improves access to the distal rectum for low anastomoses.     

Acute care nurse practitioners: the role in neuroscience critical care

In order to meet the needs of the high acuity population in today's critical care environment, the role of the Acute Care Nurse practitioner (ACNP) has been adopted by many intensive care units (ICU's) across the country, including specialized neurocritical care units. In this chapter we will provide a brief historical review of the ACNP as well as their function in various ICU settings. Lastly, we will describe the current role of the ACNP in the Neurosciences Critical Care Unit at the Johns Hopkins Hospital as well as future plans and challenges of the role.     

The effect of papaverine on ion channels in rat basilar smooth muscle cells

OBJECTIVES: Papaverine has been used in treating vasospasm following subarachnoid hemorrhage (SAH). However, its action mechanism for cerebral vascular relaxation is not clear. Potassium and calcium channels are closely related to the contraction and relaxation of cerebral smooth muscle. Therefore, to identify the role of potassium and calcium channels in papaverine-induced vascular relaxation, we examined the effect of papaverine on potassium and calcium channels in freshly isolated smooth muscle cells from rat basilar artery. METHOD: The isolation of rat basilar smooth muscle cells was performed by special techniques. The whole cell currents were recorded by whole cell patch clamp technique in freshly isolated smooth muscle cells from rat basilar artery. Papaverine was added to the bath solution. RESULTS: Papaverine of 100 microM into bath solution increased the amplitude of the outward K(+) current which was completely blocked by BKCa blocker, IBX (iberiotoxin) and a calcium chelator, BAPTA (1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid) in whole cell mode. Papaverine (100 microM) also inhibited L type Ca(2+) current recorded in isolated smooth muscle cells from rat basilar artery. DISCUSSION: These results strongly suggest that Ca(2+)-activated potassium channels and L type Ca(2+) channels may be involved in papaverine-induced vascular relaxation in rat basilar artery.     

The microglial gene regulatory network activated by interferon-gamma

We have analysed the microglial pathway stimulated by interferon-gamma (IFN-gamma) using an in silico approach employing a database of eukaryotic molecular interactions and a microarray dataset validated by quantitative real-time PCR (qRT-PCR). Following IFN-gamma stimulation, production of neuroprotective factors by microglia was found to be reduced while caspase 1 and serping1 which are involved in cell death cascades are up-regulated suggesting a safeguarding mechanism. Extracellular matrix interactions and intracellular protein degradation are altered in concert with these changes. The regulatory network of IFN-gamma responsive microglial genes is outlined in detail and differentially expressed genes are mapped to their respective cellular compartments. A pathway approach to the analysis of microarray data is advocated since overlaying pathway and actual expression data as shown here greatly facilitates understanding the biological meaning of a gene regulatory network. In addition, genes of similar function that are differentially regulated are less likely to be false positives than single unrelated genes.     

Ictal hyperperfusion patterns in relation to ictal scalp EEG patterns in patients with unilateral hippocampal sclerosis: a SPECT study

PURPOSE: The aims of the present study were to explore the relation between ictal scalp EEG patterns and ictal hyperperfusion patterns in patients with unilateral hippocampal sclerosis-associated mesial temporal lobe epilepsy (HS-MTLE) by using semiquantitative single-photon emission computed tomography (SPECT) analysis and to assess clinical significance of ictal hyperperfusion patterns. METHODS: We studied retrospectively 39 consecutive patients with surgically proven HS-MTLE. All had both interictal and ictal SPECTs with the tracer injection during a complex partial seizure (CPS) typical of MTLE semiology. According to initial ictal discharge (IID) frequency on scalp EEG, two lateralizing patterns were identified: (a) a sustained regular 5- to 9-Hz rhythm with a restricted temporal or subtemporal distribution (group 1); and (b) an irregular 2- to 5-Hz rhythm with a widespread distribution (group 2). We performed group analysis by using statistical parametric mapping (SPM) of paired ictal-interictal SPECTs to identify regions of significant ictal hyperperfusion and compared clinical characteristics, tracer-injection time, semiology, pathologic HS grade, and surgical outcome between two groups. RESULTS: Of the 39 patients, 19 patients (10 males, nine right HS) were designated as group 1, and the remaining 20 patients (eight males, seven right HS), group 2. Group 1 showed hyperperfusion mainly confined to the ipsilateral temporal lobe, whereas group 2 showed widespread hyperperfusion in the extratemporal structures such as ipsilateral basal ganglia, brainstem, and bilateral thalamus, in addition to the ipsilateral temporal lobe. No significant difference was found between two groups in clinical characteristics, injection time, pathologic HS grade, and surgical outcome. Among semiologic features, dystonic limb posturing was more frequently observed in group 2 (p = 0.006). CONCLUSIONS: Scalp EEG IID frequency in HS-MTLE can be an important determining factor of ictal hyperperfusion patterns. The lack of difference in surgical outcome between two groups implies that different hyperperfusion patterns, according to their IID frequencies, reflect only preferential pathways of ictal propagation rather than intrinsic epileptogenic region.     

Topographic patterns of brain functional impairment progression according to clinical severity staging in 116 Alzheimer disease patients: FDG-PET study

The study aimed to explore topographic progression pattern of brain functional impairment according to clinical stage in Alzheimer disease (AD). One hundred and sixteen AD patients and 25 normal subjects underwent a [18F] fluorodeoxyglucose-positron emission tomography scan. Regional cerebral glucose metabolism was compared between severity groups based on the Clinical Dementia Rating through voxel-based analyses. As clinical severity progressed, hypometabolic areas gradually increased, involving initially posterior cingulate cortex, later temporoparietal, and finally frontal and some subcortical areas. The results indicate that progression patterns of hypometabolism in AD are close to that of typical neuropathology, but that they do not fully coincide with it.     

Qualitative and quantitative determination of the caffeoylquinic acids on the Korean mountainous vegetables used for Chwinamul and their peroxynitrite-scavenging effect

Mountainous vegetables called chwinamul are used in Korea to promote health. Chwinamul was obtained from several plants belonging to the Compositae — e.g., Kalimeris yomena, Aster scaber, Solidago virga var. gigantea, Solidago viragaurea var. asiatica, Saussurea grandifolia, Ainsliaea acerifolia — were used for our experiments. Analytical methods for simultaneous determination of the caffeoylquinic acids (3,4-di-O-caffeoylquinic acid, 3,5-di-O-dicaffeoyl-epi-quinic acid, 3,5-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, 3-O-p-coumaroyl-caffeoylquinic acids) were established for chwinamul. The kinds of constituents were identified from HPLC chromatograms and it was possible to calculate the percentage (w/w) of seven of these compounds in the dried plants and in the extracts. The proportion of caffeoylquinic acids in the extracts ranged from 20.25 to 38.35%. Since it is known that peroxynitrite (ONOO⁻)-scavenging is beneficial for amelioration of obesity, diabetes mellitus, atherosclerosis and even Alzheimer’s disease, assays for peroxynitrite-scavenging activity were performed on the seven chwinamul plants. Of the tested extracts, the MeOH extract of A. acerifolia had the most potent effect (IC₅₀ 1.49 ± 0.68 μg/mL). These results suggest that chwinamul vegetables can be used for treatment or prevention of peroxynitrite-related diseases.