305 research outputs found
Cytosolic Calmodulin Is Increased in SK-N-SH Human Neuroblastoma Cells Due to Release of Calcium from Intracellular Stores
Muscarinic receptor stimulation elicits a redistribution of calmodulin (CaM) from the membrane fraction to cytosol in the human neuroblastoma cell line SK-N-SH. Increasing the intracellular Ca 2+ concentration with ionomycin also elevates cytosolic CaM. The aim of this study was to investigate the roles of extracellular and intracellular Ca 2+ pools in the muscarinic receptor-mediated increases in cytosolic CaM in SK-N-SH cells. Stimulus-mediated changes in intracellular Ca 2+ were monitored in fura-2-loaded cells, and CaM was measured by radioimmunoassay in the 100,000- g cytosol and membrane fractions. The influx of extracellular Ca 2+ normally seen with carbachol treatment in SK-N-SH cells was eliminated by pretreatment with the nonspecific Ca 2+ channel blocker Ni 2+ . Blocking the influx of extracellular Ca 2+ had no effect on carbachol-mediated increases in cytosolic CaM (168 18% of control values for carbachol treatment alone vs. 163 28% for Ni 2+ and carbachol) or decreases in membrane CaM. Similarly, removal of extracellular Ca 2+ from the medium did not affect carbachol-mediated increases in cytosolic CaM (168 26% of control). On the other hand, prevention of the carbachol-mediated increase of intracellular free Ca 2+ by pretreatment with the cell-permeant Ca 2+ chelator BAPTA/AM did attenuate the carbachol-mediated increase in cytosolic CaM (221 37% of control without BAPTA/AM vs. 136 13% with BAPTA/AM). The effect of direct entry of extracellular Ca 2+ into the cell by K + depolarization was assessed. Incubation of SK-N-SH cells with 60 m M K + elicited an immediate and persistent increase in intracellular free Ca 2+ concentration, but there was no corresponding alteration in CaM localization. On the contrary, in cells where intracellular Ca 2+ was directly elevated by thapsigargin treatment, cytosolic CaM was elevated for at least 30 min while particulate CaM was decreased. In addition, treatment with ionomycin in the absence of extracellular Ca 2+ , which releases Ca 2+ from intracellular stores, induced an increase in cytosolic CaM (203 30% of control). The mechanism for the CaM release may involve activation of the isozyme of protein kinase C, which was translocated from cytosol to membranes much more profoundly by thapsigargin than by K + depolarization. These data demonstrate that release of Ca 2+ from the intracellular store is important for the carbachol-mediated redistribution of CaM in human neuroblastoma SK-N-SH cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66213/1/j.1471-4159.1998.70010139.x.pd
Comparing bladder neck contracture rate between robotic intracorporeal and extracorporeal neobladder construction
Robot-assisted radical cystectomy (RARC) has become more accessible to surgeons worldwide, and descriptions of intracorporeal urinary diversion techniques, such as orthotopic neobladder construction, have increased. In this study, we aim to compare the rate of bladder neck contracture (BNC) formation between RARC and two different urinary diversion techniques. We retrospectively reviewed our institutional database for patients with bladder cancer who underwent RARC with intracorporeal neobladder (ICNB) construction (n = 11) or extracorporeal neobladder (ECNB) construction (n = 11) between 2012 and 2020. BNC was defined by the need for an additional surgical procedure (e.g., dilatation, urethrotomy). Patients who underwent RARC with ICNB (n = 11) were compared to patients who underwent RARC with ECNB (n = 11) across patient characteristics and postoperative BNC formation rates. Kaplan-Meier curves were generated for freedom from BNC based on the neobladder approach and compared with the log-rank test. For patients who received an ECNB, 73% (8/11) developed a BNC; in comparison, none of the patients in the ICNB group experienced a BNC. Kaplan-Meier survival analysis demonstrates the ECNB group\u27s median probability of freedom from BNC as 1.3 years, while the ICNB group was free of BNC over the study period (p \u3c 0.001). RARC with ICNB creation demonstrated a significantly reduced BNC rate in contrast to RARC with ECNB construction. Longer-term follow-up is needed to assess the durability of this difference in BNC rates
Endogenous Bax Translocation in SH-SY5Y Human Neuroblastoma Cells and Cerebellar Granule Neurons Undergoing Apoptosis
Changes at the mitochondria are an early, required step in apoptosis in various cell types. We used western blot analysis to demonstrate that the proapoptotic protein Bax translocated from the cytosolic to the mitochondrial fraction in SH-SY5Y human neuroblastoma cells undergoing staurosporine- or EGTA-mediated apoptosis. Levels of mitochondrial Bax increased 15 min after staurosporine treatment. In EGTA-treated cells, increased levels of mitochondrial Bax were seen at 4 h, consistent with a slower onset of apoptosis in EGTA versus staurosporine treatments. We also demonstrate the concomitant translocation of cytochrome c from the mitochondrial to the cytosolic fractions. We correlated these translocations with changes in caspase-3-like activity. An increase in caspase-3-like activity was evident 2 h after staurosporine treatment. Inhibition of the mitochondrial permeability transition had no effect on Bax translocation or caspase-3-like activity in staurosporine-treated SH-SY5Y cells. In primary cultures of cerebellar granule neurons undergoing low K + -mediated apoptosis, Bax translocation to the mitochondrial fraction was evident at 3 h. Cytochrome c release into the cytosol was not significant until 8 h after treatment. These data support a model of apoptosis in which Bax acts directly at the mitochondria to allow the release of cytochrome c.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66150/1/j.1471-4159.1999.0721899.x.pd
Phos-Tag-Based Analysis of Myosin Regulatory Light Chain Phosphorylation in Human Uterine Myocytes
The 'phosphate-binding tag' (phos-tag) reagent enables separation of phospho-proteins during SDS-PAGE by impeding migration proportional to their phosphorylation stoichiometry. Western blotting can then be used to detect and quantify the bands corresponding to the phospho-states of a target protein. We present a method for quantification of data regarding phospho-states derived from phos-tag SDS-PAGE. The method incorporates corrections for lane-to-lane loading variability and for the effects of drug vehicles thus enabling the comparison of multiple treatments by using the untreated cellular set-point as a reference. This method is exemplified by quantifying the phosphorylation of myosin regulatory light chain (RLC) in cultured human uterine myocytes.We have evaluated and validated the concept that, when using an antibody (Ab) against the total-protein, the sum of all phosphorylation states in a single lane represents a 'closed system' since all possible phospho-states and phosphoisotypes are detected. Using this approach, we demonstrate that oxytocin (OT) and calpeptin (Calp) induce RLC kinase (MLCK)- and rho-kinase (ROK)-dependent enhancements in phosphorylation of RLC at T18 and S19. Treatment of myocytes with a phorbol ester (PMA) induced phosphorylation of S1-RLC, which caused a mobility shift in the phos-tag matrices distinct from phosphorylation at S19.We have presented a method for analysis of phospho-state data that facilitates quantitative comparison to a reference control without the use of a traditional 'loading' or 'reference' standard. This analysis is useful for assessing effects of putative agonists and antagonists where all phospho-states are represented in control and experimental samples. We also demonstrated that phosphorylation of RLC at S1 is inducible in intact uterine myocytes, though the signal in the resting samples was not sufficiently abundant to allow quantification by the approach used here
Health behaviors and risk factors in those who use complementary and alternative medicine
<p>Abstract</p> <p>Background</p> <p>Surveys have generally found that individuals more likely to use complementary and alternative medicine are female, live in the western United States, are likely to have a health complaint, and have a higher socioeconomic status than do nonusers. What is not known is the extent to which those who use complementary and alternative medicine also engage in positive health behaviors, such as smoking cessation or increased physical activity and/or exhibit fewer health risk factors such as obesity. This has been identified as a key research question in a recent Institute of Medicine report. In the present study we sought to determine whether the use of complementary and alternative medicine is associated with health behaviors or risk factors known to impact on health status.</p> <p>Methods</p> <p>The current study is a cross-sectional regression analysis using data from the 2002 National Health Interview Survey. Data were collected in-person from 31,044 adults throughout the 50 states and the District of Columbia.</p> <p>Results</p> <p>After controlling for a range of other factors, we found that engaging in leisure-time physical activity, having consumed alcohol in one's life but not being a current heavy drinker, and being a former smoker are independently associated with the use of CAM. Obese individuals are slightly less likely to use CAM than individuals with a healthy body-mass index. No significant associations were observed between receipt of an influenza vaccine and CAM use.</p> <p>Conclusion</p> <p>Those engaging in positive health behaviors and exhibiting fewer health risk factors are more likely to use CAM than those who forgo positive health behaviors or exhibit more health risk factors. The fact that users of CAM tend to pursue generally healthy lifestyles suggests that they may be open to additional recommendations toward optimizing their health.</p
Preservation of Mouse Sperm by Convective Drying and Storing in 3-O-Methyl-D-Glucose
With the fast advancement in the genetics and bio-medical fields, the vast number of valuable transgenic and rare genetic mouse models need to be preserved. Preservation of mouse sperm by convective drying and subsequent storing at above freezing temperatures could dramatically reduce the cost and facilitate shipping. Mouse sperm were convectively dried under nitrogen gas in the Na-EGTA solution containing 100 mmol/L 3-O-methyl-D-glucose and stored in LiCl sorption jars (Relative Humidity, RH, 12%) at 4°C and 22°C for up to one year. The functionality of these sperm samples after storage was tested by intracytoplasmic injection into mouse oocytes. The percentages of blastocysts produced from sperm stored at 4°C for 1, 2, 3, 6, and 12 months were 62.6%, 53.4%, 39.6%, 33.3%, and 30.4%, respectively, while those stored at 22°C for 1, 2, and 3 months were 28.8%, 26.6%, and 12.2%, respectively. Transfer of 38 two- to four-cell embryos from sperm stored at 4°C for 1 year produced two live pups while 59 two- to four-cell embryos from sperm stored at 22°C for 3 months also produced two live pups. Although all the pups looked healthy at 3 weeks of age, normality of offspring produced using convectively dried sperm needs further investigation. The percentages of blastocyst from sperm stored in the higher relative humidity conditions of NaBr and MgCl2 jars and driest condition of P2O5 jars at 4°C and 22°C were all lower. A simple method of mouse sperm preservation is demonstrated. Three-O-methyl-D-glucose, a metabolically inactive derivative of glucose, offers significant protection for dried mouse sperm at above freezing temperatures without the need for poration of cell membrane
iTools: A Framework for Classification, Categorization and Integration of Computational Biology Resources
The advancement of the computational biology field hinges on progress in three fundamental directions – the development of new computational algorithms, the availability of informatics resource management infrastructures and the capability of tools to interoperate and synergize. There is an explosion in algorithms and tools for computational biology, which makes it difficult for biologists to find, compare and integrate such resources. We describe a new infrastructure, iTools, for managing the query, traversal and comparison of diverse computational biology resources. Specifically, iTools stores information about three types of resources–data, software tools and web-services. The iTools design, implementation and resource meta - data content reflect the broad research, computational, applied and scientific expertise available at the seven National Centers for Biomedical Computing. iTools provides a system for classification, categorization and integration of different computational biology resources across space-and-time scales, biomedical problems, computational infrastructures and mathematical foundations. A large number of resources are already iTools-accessible to the community and this infrastructure is rapidly growing. iTools includes human and machine interfaces to its resource meta-data repository. Investigators or computer programs may utilize these interfaces to search, compare, expand, revise and mine meta-data descriptions of existent computational biology resources. We propose two ways to browse and display the iTools dynamic collection of resources. The first one is based on an ontology of computational biology resources, and the second one is derived from hyperbolic projections of manifolds or complex structures onto planar discs. iTools is an open source project both in terms of the source code development as well as its meta-data content. iTools employs a decentralized, portable, scalable and lightweight framework for long-term resource management. We demonstrate several applications of iTools as a framework for integrated bioinformatics. iTools and the complete details about its specifications, usage and interfaces are available at the iTools web page http://iTools.ccb.ucla.edu
Severity dependent distribution of impairments in PSP and CBS: Interactive visualizations
BACKGROUND: Progressive supranuclear palsy (PSP) -Richardson's Syndrome and Corticobasal Syndrome (CBS) are the two classic clinical syndromes associated with underlying four repeat (4R) tau pathology. The PSP Rating Scale is a commonly used assessment in PSP clinical trials; there is an increasing interest in designing combined 4R tauopathy clinical trials involving both CBS and PSP. OBJECTIVES: To determine contributions of each domain of the PSP Rating Scale to overall severity and characterize the probable sequence of clinical progression of PSP as compared to CBS. METHODS: Multicenter clinical trial and natural history study data were analyzed from 545 patients with PSP and 49 with CBS. Proportional odds models were applied to model normalized cross-sectional PSP Rating Scale, estimating the probability that a patient would experience impairment in each domain using the PSP Rating Scale total score as the index of overall disease severity. RESULTS: The earliest symptom domain to demonstrate impairment in PSP patients was most likely to be Ocular Motor, followed jointly by Gait/Midline and Daily Activities, then Limb Motor and Mentation, and finally Bulbar. For CBS, Limb Motor manifested first and ocular showed less probability of impairment throughout the disease spectrum. An online tool to visualize predicted disease progression was developed to predict relative disability on each subscale per overall disease severity. CONCLUSION: The PSP Rating Scale captures disease severity in both PSP and CBS. Modelling how domains change in relation to one other at varying disease severities may facilitate detection of therapeutic effects in future clinical trials
Histological Evaluation of Diabetic Neurodegeneration in the Retina of Zucker Diabetic Fatty (ZDF) Rats
In diabetes, retinal dysfunctions exist prior to clinically detectable vasculopathy, however the pathology behind these functional deficits is still not fully established. Previously, our group published a detailed study on the retinal histopathology of type 1 diabetic (T1D) rat model, where specific alterations were detected. Although the majority of human diabetic patients have type 2 diabetes (T2D), similar studies on T2D models are practically absent. To fill this gap, we examined Zucker Diabetic Fatty (ZDF) rats - a model for T2D - by immunohistochemistry at the age of 32 weeks. Glial reactivity was observed in all diabetic specimens, accompanied by an increase in the number of microglia cells. Prominent outer segment degeneration was detectable with changes in cone opsin expression pattern, without a decrease in the number of labelled elements. The immunoreactivity of AII amacrine cells was markedly decreased and changes were detectable in the number and staining of some other amacrine cell subtypes, while most other cells examined did not show any major alterations. Overall, the retinal histology of ZDF rats shows a surprising similarity to T1D rats indicating that despite the different evolution of the disease, the neuroretinal cells affected are the same in both subtypes of diabetes
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