Following its evoked release, dopamine (DA) signaling is rapidly terminated by presynaptic reuptake, mediated by the cocaine-sensitive DA transporter (DAT). DAT surface availability is dynamically regulated by endocytic trafficking, and direct protein kinase C (PKC) activation acutely diminishes DAT surface expression by accelerating DAT internalization. Previous cell line studies demonstrated that PKC-stimulated DAT endocytosis requires both Ack1 inactivation, which releases a DAT-specific endocytic brake, and the neuronal GTPase, Rit2, which binds DAT. However, it is unknown whether Rit2 is required for PKC-stimulated DAT endocytosis in DAergic terminals or whether there are region- and/or sex-dependent differences in PKC-stimulated DAT trafficking. Moreover, the mechanisms by which Rit2 controls PKC-stimulated DAT endocytosis are unknown. Here, we directly examined these important questions. Ex vivo studies revealed that PKC activation acutely decreased DAT surface expression selectively in ventral, but not dorsal, striatum. AAV-mediated, conditional Rit2 knockdown in DAergic neurons impacted baseline DAT surface:intracellular distribution in DAergic terminals from female ventral, but not dorsal, striatum. Further, Rit2 was required for PKC-stimulated DAT internalization in both male and female ventral striatum. FRET and surface pulldown studies in cell lines revealed that PKC activation drives DAT-Rit2 surface dissociation and that the DAT N terminus is required for both PKC-mediated DAT-Rit2 dissociation and DAT internalization. Finally, we found that Rit2 and Ack1 independently converge on DAT to facilitate PKC-stimulated DAT endocytosis. Together, our data provide greater insight into mechanisms that mediate PKC-regulated DAT internalization and reveal unexpected region-specific differences in PKC-stimulated DAT trafficking in bona fide DAergic terminals.

Bacterial biofilms are cellular communities that produce an adherent matrix. Exopolysaccharides are key structural components of this matrix and are required for the assembly and architecture of biofilms produced by a wide variety of microorganisms. The human bacterial pathogens Escherichia coli and Salmonella enterica produce a biofilm matrix composed primarily of the exopolysaccharide phosphoethanolamine (pEtN) cellulose. Once thought to be composed of only underivatized cellulose, the pEtN modification present in these matrices has been implicated in the overall architecture and integrity of the biofilm. However, an understanding of the mechanism underlying pEtN derivatization of the cellulose exopolysaccharide remains elusive. The bacterial cellulose synthase subunit G (BcsG) is a predicted inner membrane–localized metalloenzyme that has been proposed to catalyze the transfer of the pEtN group from membrane phospholipids to cellulose. Here we present evidence that the C-terminal domain of BcsG from E. coli (EcBcsGΔN) functions as a phosphoethanolamine transferase in vitro with substrate preference for cellulosic materials. Structural characterization of EcBcsGΔN revealed that it belongs to the alkaline phosphatase superfamily, contains a Zn2+ ion at its active center, and is structurally similar to characterized enzymes that confer colistin resistance in Gram-negative bacteria. Informed by our structural studies, we present a functional complementation experiment in E. coli AR3110, indicating that the activity of the BcsG C-terminal domain is essential for integrity of the pellicular biofilm. Furthermore, our results established a similar but distinct active-site architecture and catalytic mechanism shared between BcsG and the colistin resistance enzymes.

(University of Arkansas) Giant elliptical galaxies are not as likely as disk-shaped galaxies, such as our own Milky Way, to be cradles of technological civilizations, according to a recent paper by a University of Arkansas astrophysicist.

The U.S. Navy is in “rough waters” and suffering from leadership failures, the diplomat tapped to be the next Navy secretary told a Senate committee Thursday. Kenneth J. Braithwaite, the ambassador to Norway and a retired Navy rear admiral, faced repeated questions about recent crises that have rocked the service, including the firing of an aircraft carrier captain who urged faster action to fight a coronavirus outbreak on his ship and the subsequent resignation of the acting secretary who fired him. Braithwaite said that Navy culture has been tarnished and trust in the service's leaders has broken down.

Belinda S. O’Connell
Aug 1, 2001; 14:
Articles

Objective: To assess the feasibility and accuracy of Cerenkov Luminescence Imaging (CLI) for assessment of surgical margins intraoperatively during radical prostatectomy (RPE). Methods: A single centre feasibility study included 10 patients with high-risk primary prostate cancer (PC). ⁶⁸Ga-PSMA PET/CT scans were performed followed by RPE and intraoperative CLI of the excised prostate. In addition to imaging the intact prostate, in the first two patients the prostate gland was incised and imaged with CLI to visualise the primary tumour. We compared the tumour margin status on CLI to postoperative histopathology. Measured CLI intensities were determined as tumour to background ratio (TBR). Results: Tumour cells were successfully detected on the incised prostate CLI images as confirmed by histopathology. 3 of 10 men had histopathological positive surgical margins (PSMs), and 2 of 3 PSMs were accurately detected on CLI. Overall, 25 (72%) out of 35 regions of interest (ROIs) proved to visualize a tumour signal according to standard histopathology. The median tumour radiance in these areas was 11301 photons/s/cm²/sr (range 3328 - 25428 photons/s/cm²/sr) and median TBR was 4.2 (range 2.1 – 11.6). False positive signals were seen mainly at the prostate base with PC cells overlaid by benign tissue. PSMA-immunohistochemistry (PSMA-IHC) revealed strong PSMA staining of benign gland tissue, which impacts measured activities. Conclusion: This feasibility showed that ⁶⁸Ga-PSMA CLI is a new intraoperative imaging technique capable of imaging the entire specimen’s surface to detect PC tissue at the resection margin. Further optimisation of the CLI protocol, or the use of lower-energetic imaging tracers such as ¹⁸F-PSMA, are required to reduce false positives. A larger study will be performed to assess diagnostic performance.

Proteins that bind carbohydrate structures can serve as tools to quantify or localize specific glycans in biological specimens. Such proteins, including lectins and glycan-binding antibodies, are particularly valuable if accurate information is available about the glycans that a protein binds. Glycan arrays have been transformational for uncovering rich information about the nuances and complexities of glycan-binding specificity. A challenge, however, has been the analysis of the data. Because protein-glycan interactions are so complex, simplistic modes of analyzing the data and describing glycan-binding specificities have proven inadequate in many cases. This review surveys the methods for handling high-content data on protein-glycan interactions. We contrast the approaches that have been demonstrated and provide an overview of the resources that are available. We also give an outlook on the promising experimental technologies for generating new insights into protein-glycan interactions, as well as a perspective on the limitations that currently face the field.

Triple-negative breast cancer (TNBC) is characterized by its aggressive biology, early metastatic spread, and poor survival outcomes. TNBC lacks expression of the targetable receptors found in other breast cancer subtypes, mandating use of cytotoxic chemotherapy. However, resistance to chemotherapy is a significant problem, encountered in about two-thirds of TNBC patients, and new strategies are needed to mitigate resistance. In this issue of the Journal of Biological Chemistry, Geck et al. report that TNBC cells are highly sensitive to inhibition of the de novo polyamine synthesis pathway and that inhibition of this pathway sensitizes cells to TNBC-relevant chemotherapy, uncovering new opportunities for addressing chemoresistance.

Treatment of patients with triple-negative breast cancer (TNBC) is limited by a lack of effective molecular therapies targeting this disease. Recent studies have identified metabolic alterations in cancer cells that can be targeted to improve responses to standard-of-care chemotherapy regimens. Using MDA-MB-468 and SUM-159PT TNBC cells, along with LC-MS/MS and HPLC metabolomics profiling, we found here that exposure of TNBC cells to the cytotoxic chemotherapy drugs cisplatin and doxorubicin alter arginine and polyamine metabolites. This alteration was because of a reduction in the levels and activity of a rate-limiting polyamine biosynthetic enzyme, ornithine decarboxylase (ODC). Using gene silencing and inhibitor treatments, we determined that the reduction in ODC was mediated by its negative regulator antizyme, targeting ODC to the proteasome for degradation. Treatment with the ODC inhibitor difluoromethylornithine (DFMO) sensitized TNBC cells to chemotherapy, but this was not observed in receptor-positive breast cancer cells. Moreover, TNBC cell lines had greater sensitivity to single-agent DFMO, and ODC levels were elevated in TNBC patient samples. The alterations in polyamine metabolism in response to chemotherapy, as well as DFMO-induced preferential sensitization of TNBC cells to chemotherapy, reported here suggest that ODC may be a targetable metabolic vulnerability in TNBC.

Geranylgeranoic acid (GGA) originally was identified in some animals and has been developed as an agent for preventing second primary hepatoma. We previously have also identified GGA as an acyclic diterpenoid in some medicinal herbs. Recently, we reported that in human hepatoma-derived HuH-7 cells, GGA is metabolically labeled from ¹³C-mevalonate. Several cell-free experiments have demonstrated that GGA is synthesized through geranylgeranial by oxygen-dependent oxidation of geranylgeraniol (GGOH), but the exact biochemical events giving rise to GGA in hepatoma cells remain unclear. Monoamine oxidase B (MOAB) has been suggested to be involved in GGOH oxidation. Here, using two human hepatoma cell lines, we investigated whether MAOB contributes to GGA biosynthesis. Using either HuH-7 cell lysates or recombinant human MAOB, we found that: 1) the MAO inhibitor tranylcypromine dose-dependently downregulates endogenous GGA levels in HuH-7 cells; and 2) siRNA-mediated MAOB silencing reduces intracellular GGA levels in HuH-7 and Hep3B cells. Unexpectedly, however, CRISPR/Cas9-generated MAOB-KO human hepatoma Hep3B cells had GGA levels similar to those in MAOB-WT cells. A sensitivity of GGA levels to siRNA-mediated MAOB downregulation was recovered when the MAOB-KO cells were transfected with a MAOB-expression plasmid, suggesting that MAOB is the enzyme primarily responsible for GGOH oxidation and that some other latent metabolic pathways may maintain endogenous GGA levels in the MAOB-KO hepatoma cells. Along with the previous findings, these results provide critical insights into the biological roles of human MAOB and provide evidence that hepatic MAOB is involved in endogenous GGA biosynthesis via GGOH oxidation.

Triple-negative breast cancer (TNBC) is characterized by its aggressive biology, early metastatic spread, and poor survival outcomes. TNBC lacks expression of the targetable receptors found in other breast cancer subtypes, mandating use of cytotoxic chemotherapy. However, resistance to chemotherapy is a significant problem, encountered in about two-thirds of TNBC patients, and new strategies are needed to mitigate resistance. In this issue of the Journal of Biological Chemistry, Geck et al. report that TNBC cells are highly sensitive to inhibition of the de novo polyamine synthesis pathway and that inhibition of this pathway sensitizes cells to TNBC-relevant chemotherapy, uncovering new opportunities for addressing chemoresistance.

IN AN effort to alleviate misconceptions and misinterpretations of our current COVID-19 reality, and to create the idea that human beings deserve respect, especially when they are ill, ListenMi News has collaborated with the International...

Adipose tissue macrophages (ATMs) are involved in the development of insulin resistance in obesity. We have recently shown that myeloid cell–specific reduction of HMG-CoA reductase (Hmgcr^m–/m–), which is the rate-limiting enzyme in cholesterol biosynthesis, protects against atherosclerosis by inhibiting macrophage migration in mice. We hypothesized that ATMs are harder to accumulate in Hmgcr^m–/m– mice than in control Hmgcr^fl/fl mice in the setting of obesity. To test this hypothesis, we fed Hmgcr^m–/m– and Hmgcr^fl/fl mice a high-fat diet (HFD) for 24 weeks and compared plasma glucose metabolism as well as insulin signaling and histology between the two groups. Myeloid cell–specific reduction of Hmgcr improved glucose tolerance and insulin sensitivity without altering body weight in the HFD-induced obese mice. The improvement was due to a decrease in the number of ATMs. The ATMs were reduced by decreased recruitment of macrophages as a result of their impaired chemotactic activity. These changes were associated with decreased expression of proinflammatory cytokines in adipose tissues. Myeloid cell–specific reduction of Hmgcr also attenuated hepatic steatosis. In conclusion, reducing myeloid HMGCR may be a promising strategy to improve insulin resistance and hepatic steatosis in obesity.

LONDON — Britain’s minister for the environment, food and rural affairs says Prime Minister Boris Johnson won’t be announcing immediate changes to the country’s coronavirus lockdown when he addresses the nation on Sunday....

Burnout is a problem in healthcare - it’s a problem for individuals, those who experience it and decide to leave a career they formerly loved, but it’s also a problem for our healthcare system. Burnout is associated with an increase in medical errors, and poor quality of care. Fundamentally it’s a patient safety issue. But, unlike other patient...

THE EDITOR, Madam: The Jamaican Government and local private-sector power brokers are still way behind and woefully lacking in investing, financially and otherwise, in Jamaica’s number one most powerful, most famous, most influential, and most...

9 July 2014

19 December 2014

This research paper sets out recommendations for enhanced dialogue and intensified international cooperation that could significantly improve the functioning of global mineral markets.

Research Event

Event participants

HE Dr Kayode Fayemi, Minister of Solid Minerals Development, Nigeria
HE Aminu Bello Masari, Governor of Katsina State, Nigeria
Chair: Chi Onwurah MP, Vice Chair, All Party Parliamentary Group on Nigeria

Type 1 diabetes mellitus (T1DM) has traditionally been characterized by a complete destruction of β-cell mass (BCM); however, there is growing evidence of possible residual BCM present in T1DM. Given the absence of in vivo tools to measure BCM, routine clinical measures of β-cell function (e.g., C-peptide release) may not reflect BCM. We previously demonstrated the potential utility of PET imaging with the dopamine D₂ and D₃ receptor agonist 3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4]oxazin-9-ol (¹¹C-(+)-PHNO) to differentiate between healthy control (HC) and T1DM individuals. Methods: Sixteen individuals participated (10 men, 6 women; 9 HCs, 7 T1DMs). The average duration of diabetes was 18 ± 6 y (range, 14–30 y). Individuals underwent PET/CT scanning with a 120-min dynamic PET scan centered on the pancreas. One- and 2-tissue-compartment models were used to estimate pancreas and spleen distribution volume. Reference region approaches (spleen as reference) were also investigated. Quantitative PET measures were correlated with clinical outcome measures. Immunohistochemistry was performed to examine colocalization of dopamine receptors with endocrine hormones in HC and T1DM pancreatic tissue. Results: C-peptide release was not detectable in any T1DM individuals, whereas proinsulin was detectable in 3 of 5 T1DM individuals. Pancreas SUV ratio minus 1 (SUVR-1) (20–30 min; spleen as reference region) demonstrated a statistically significant reduction (–36.2%) in radioligand binding (HCs, 5.6; T1DMs, 3.6; P = 0.03). Age at diagnosis correlated significantly with pancreas SUVR-1 (20–30 min) (R² = 0.67, P = 0.025). Duration of diabetes did not significantly correlate with pancreas SUVR-1 (20–30 min) (R² = 0.36, P = 0.16). Mean acute C-peptide response to arginine at maximal glycemic potentiation did not significantly correlate with SUVR-1 (20–30 min) (R² = 0.57, P = 0.05), nor did mean baseline proinsulin (R² = 0.45, P = 0.10). Immunohistochemistry demonstrated colocalization of dopamine D₃ receptor and dopamine D₂ receptor in HCs. No colocalization of the dopamine D₃ receptor or dopamine D₂ receptor was seen with somatostatin, glucagon, or polypeptide Y. In a separate T1DM individual, no immunostaining was seen with dopamine D₃ receptor, dopamine D₂ receptor, or insulin antibodies, suggesting that loss of endocrine dopamine D₃ receptor and dopamine D₂ receptor expression accompanies loss of β-cell functional insulin secretory capacity. Conclusion: Thirty-minute scan durations and SUVR-1 provide quantitative outcome measures for ¹¹C-(+)-PHNO, a dopamine D₃ receptor–preferring agonist PET radioligand, to differentiate BCM in T1DM and HCs.

OBJECTIVE

Glucosamine is a widely used supplement typically taken for osteoarthritis and joint pain. Emerging evidence suggests potential links of glucosamine with glucose metabolism, inflammation, and cardiometabolic risk. We prospectively analyzed the association of habitual glucosamine use with risk of type 2 diabetes (T2D) and assessed whether genetic susceptibility and inflammation status might modify the association.

Greater compliance with dietary guidelines may reduce the chance of untreated caries in adults, according to a study published in the February issue of The Journal of the American Dental Association.

The ADA Health Policy Institute launched an ongoing biweekly poll the week of March 23 that shows 76% of dentists surveyed had closed their offices to all but emergency patients during the COVID-19 pandemic. Another 19% indicated their offices are closed completely.

802.11n device 20 MHz band 32 QAM 1/2 coding rate What's formula?

OBJECTIVE

Previous studies suggested that childhood prediabetes may develop prior to obesity and be associated with relative insulin deficiency. We proposed that the insulin-deficient phenotype is genetically determined and tested this hypothesis by longitudinal modeling of insulin and glucose traits with diabetes risk genotypes in the EarlyBird cohort.

An essential mineral in the body have been linked to recovery of COVID-19 patients.

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Some districts are using new “response lessons” to identify the talented students that traditional assessments miss.

Governors' races in Kentucky and Mississippi took center stage, testing the political muscle of teacher activists and yielding possible policy implications for everything from public employee pensions to teacher pay.

A group of teachers and literacy advocates are pushing back after Richard Allington, one of the country's most prominent experts on early literacy, made inflammatory claims about dyslexia at a Tennessee literacy conference this week.

This report provides an overview of the implementation of the Water plan (Mary Basin) 2006 and summarises the findings of the assessments undertaken for the last five years. The plan supports urban water supply and a variety of industries including significant agricultural production, a growing tourism industry and fisheries.

"This document is intended to summarise the current state, understanding and the use of seismic reflection method for mineral exploration. Its primary objective is to provide a point of reference, based on actual case studies, for mineral explorers interested in the application of seismic methods to their project. It provides summary information (including the purpose of the survey, acquisition methods, geometry and cost, processing procedures and key findings) that are intended to provide the reader with an objective means of assessing the cost effectiveness of the technique with respect to exploration objectives. It is also aimed at exchange of information between DETCRC sponsors, affiliates and researchers. Finally we hope that this table will help in shaping future research efforts and direction within Project 3.1, regarding the application of seismic for mineral exploration.This is only initial work and it is hoped that it will evolve into a document or a catalogue that will be extensively used by the mineral industry to achieve their exploration objectives in more efficient and effective way" -- Executive summary.

London : Longmans, Green, 1890-1893.

London : Longmans, Green, 1912-1913.

London : Longmans, Green, 1865-1869.

Halifax : Milner and Sowerby, 1856.

Halifax : Milner and Sowerby, 1860.

London : J. Johnson, 1807.

London : F.C. and J. Rivington, 1813.

Berlin : A. Hirschwald, 1870.

London : printed for J. Callow, 1814.

Edinburgh : A. and C. Black, 1873.

Madras : printed by C. Foster, 1876.

London : Bailliere, Tindall and Cox, 1884.

Toulon : chez l'auteur, 1812.

Paris : Carre et Naud, 1897.

Governors' races in Kentucky and Mississippi took center stage, testing the political muscle of teacher activists and yielding possible policy implications for everything from public employee pensions to teacher pay.

Rockville, Maryland : National Institute on Drug Abuse, 1975.