Nonalcoholic steatohepatitis (NASH) is a chronic progressive liver disease that is strongly associated with obesity. Currently, there is no approved therapy for NASH. Weight reduction is typically ...recommended, but efficacy data are lacking. We performed a randomized controlled trial to examine the effects of lifestyle intervention using a combination of diet, exercise, and behavior modification, with a goal of 7% to 10% weight reduction, on clinical parameters of NASH. The primary outcome measure was the change in NASH histological activity score (NAS) after 48 weeks of intervention. Thirty‐one overweight or obese individuals (body mass index BMI, 25–40 kg/m2) with biopsy‐proven NASH were randomized in a 2:1 ratio to receive intensive lifestyle intervention (LS) or structured education (control). After 48 weeks of intervention, participants assigned to LS lost an average of 9.3% of their weight versus 0.2% in the control group (P = 0.003). A higher proportion of participants in the LS group had a reduction of NAS of at least 3 points or had posttreatment NAS of 2 or less as compared with the control group (72% versus 30%, P = 0.03). NAS improved significantly in the LS group (from 4.4 to 2.0) in comparison with the control group (from 4.9 to 3.5) (P = 0.05). Percent weight reduction correlated significantly with improvement in NAS (r = 0.497, P = 0.007). Participants who achieved the study weight loss goal (≥7%), compared with those who lost less than 7%, had significant improvements in steatosis (−1.36 versus −0.41, P < 0.001), lobular inflammation (−0.82 versus −0.24, P = 0.03), ballooning injury (−1.27 versus −0.53, P = 0.03) and NAS (−3.45 versus −1.18, P < 0.001). Conclusion: Weight reduction achieved through lifestyle intervention leads to improvements in liver histology in NASH. (HEPATOLOGY 2009.)
Interfering with mitosis for cancer treatment is an old concept that has proven highly successful in the clinics. Microtubule poisons are used to treat patients with different types of blood or solid ...cancer since more than 20 years, but how these drugs achieve clinical response is still unclear. Arresting cells in mitosis can promote their demise, at least in a petri dish. Yet, at the molecular level, this type of cell death is poorly defined and cancer cells often find ways to escape. The signaling pathways activated can lead to mitotic slippage, cell death, or senescence. Therefore, any attempt to unravel the mechanistic action of microtubule poisons will have to investigate aspects of cell cycle control, cell death initiation in mitosis and after slippage, at single‐cell resolution. Here, we discuss possible mechanisms and signaling pathways controlling cell death in mitosis or after escape from mitotic arrest, as well as secondary consequences of mitotic errors, particularly sterile inflammation, and finally address the question how clinical efficacy of anti‐mitotic drugs may come about and could be improved.
Arresting cells in mitosis is very successful as cancer treatment, but it remains unclear how clinical responses are achieved. This review discusses mechanisms controlling cell death in mitosis, and how clinical efficacy of anti‐mitotic drugs comes about and could be improved.
The Ser-Thr kinase mammalian target of rapamycin (mTOR) controls cell growth and metabolism by stimulating glycolysis and synthesis of proteins and lipids. To further understand the central role of ...mTOR in cell physiology, we used quantitative phosphoproteomics to identify substrates or downstream effectors of the two mTOR complexes. mTOR controlled the phosphorylation of 335 proteins, including CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase). CAD catalyzes the first three steps in de novo pyrimidine synthesis. mTORC1 indirectly phosphorylated CAD-S1859 through S6 kinase (S6K). CAD-S1859 phosphorylation promoted CAD oligomerization and thereby stimulated de novo synthesis of pyrimidines and progression through S phase of the cell cycle in mammalian cells. Thus, mTORC1 also stimulates the synthesis of nucleotides to control cell proliferation.
•Fused deposition modeling 3D-printed electrode for (bio)sensors applied to real samples.•Enzymatic glucose biosensing on 3D-printed graphene-PLA electrode in plasma.•Oxygenated groups from PLA ...matrix favored enzyme immobilization by crosslinking.•Graphene-PLA 3D-printed electrochemical response improves after surface treatment.•Rapid and precise analysis of urine and saliva by pulsed amperometry using flow system.
Additive manufacturing, also known as 3D-printing, is receiving great interest by chemists due to the easy design of novel materials, fast prototyping and reducing waste, which enables large-scale fabrication of electrochemical devices. Herein we demonstrate the development of (bio)sensors for the analysis of biological fluids using 3D-printing. Fused deposition modelling was used to fabricate (bio)sensing platforms from commercially-available filaments made of polylactic acid containing graphene (G-PLA). An enzymatic glucose biosensor fabricated on the G-PLA surface was developed and applied for glucose sensing in blood plasma using chronoamperometry. Oxygenated groups from the polymeric matrix provides suitable condition to enzyme immobilization by crosslinking with glutaraldehyde. The biosensor presented a limit of detection (LOD) of 15 μmol L−1, inter-day and intra-day precision lower than 5 %, and adequate recovery values (90–105 %) for the analysis of plasma. We also show that the surface treatment of the 3D-printed sensor (mechanical polishing followed solvent immersion) provides improved electrochemical properties for the direct detection of nitrite and uric acid. Differential-pulse voltammetry and multiple-pulse amperometry under flow conditions were evaluated and compared for the determination of both species in saliva and urine. Highlights are presented for the amperometric detection within a linear range from 0.5–250 μmol L−1 for both analytes, LODs of 0.02 and 0.03 μmol L−1 for uric acid and nitrite, respectively, and high precision (RSD < 2.1 %). This report shows the first application of 3D-printed sensors and biosensors for the analysis of real biological samples with analytical features comparable to conventional modified electrodes.
Centrosomes, the main microtubule-organizing centers in animal cells, are replicated exactly once during the cell division cycle to form the poles of the mitotic spindle. Supernumerary centrosomes ...can lead to aberrant cell division and have been causally linked to chromosomal instability and cancer. Here, we report that an increase in the number of mature centrosomes, generated by disrupting cytokinesis or forcing centrosome overduplication, triggers the activation of the PIDDosome multiprotein complex, leading to Caspase-2-mediated MDM2 cleavage, p53 stabilization, and p21-dependent cell cycle arrest. This pathway also restrains the extent of developmentally scheduled polyploidization by regulating p53 levels in hepatocytes during liver organogenesis. Taken together, the PIDDosome acts as a first barrier, engaging p53 to halt the proliferation of cells carrying more than one mature centrosome to maintain genome integrity.
A new disposable microfluidic electrochemical paper-based device (ePAD) consisting of two spot sensors in the same working electrode for the simultaneous determination of uric acid and creatinine was ...developed. The spot 1 surface was modified with graphene quantum dots for direct uric acid oxidation and spot 2 surface modified with graphene quantum dots, creatininase and a ruthenium electrochemical mediator for creatinine oxidation. The ePAD was employed to construct an electrochemical sensor (based on square wave voltammetry analysis) for the simultaneous determination of uric acid and creatinine in the 0.010–3.0 µmol L−1 range. The device showed excellent analytical performance with a very low simultaneous detection limit of 8.4 nmol L−1 to uric acid and 3.7 nmol L−1 to creatinine and high selectivity. The ePAD was applied to the rapid and successful determination of those clinical biomarkers in human urine samples.
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•An ePAD used for clinical biomarkers determination.•The ePAD consisting of two spot sensors in the same working electrode.•The spot 1 surface with graphene quantum dots for direct uric acid oxidation.•The spot 2 surface with GQDs, creatininase and an redox mediator for creatinine oxidation.•The ePAD showed high sensitivity for simultaneous determination of biomarkers.
Pathologists often incorporate modifying phrases in their diagnosis to imply varying levels of diagnostic certainty; however, what is implied by the pathologists is not equivalent with what is ...perceived by the referring physicians and patients. This discordance can have significant implications in management, safety, and cost. We intend to identify lack of consistency in interpretation of modifying phrases by comparing perceived level of certainty by pathologists and non-pathologists, and introduce a standard scheme for reporting uncertainty in pathology reports using the experience with imaging reporting and data systems. In this study, a list of 18 most commonly used modifying phrases in pathology reports was distributed among separate cohorts of pathologists (
N
= 17) and non-pathology clinicians (
N
= 225) as a questionnaire survey, and the participants were asked to assign a certainty level to each phrase. All the participants had practice privileges in Brown University-affiliated teaching hospitals. The survey was completed by 207 participants (17 pathologists, 190 non-pathologists). It reveals a significant discordance between the interpretations of the modifying phrases between the two cohorts, with significant variations in subgroups of non-pathology clinicians. Also there is disagreement between pathologists and other clinicians regarding the causes of miscommunication triggered by pathology reports. Pathologists and non-pathology clinicians should be mindful of the potential sources of misunderstanding of pathology reports and take necessary actions to prevent and clarify the uncertainties. Using a standard scheme for reporting uncertainty in pathology reports is recommended.
Since many successful dieters regain the weight they lose, programs that teach maintenance skills are needed. We developed a maintenance program based on self-regulation theory and tested the ...efficacy of delivering the program face to face or over the Internet.
We randomly assigned 314 participants who had lost a mean of 19.3 kg of body weight in the previous 2 years to one of three groups: a control group, which received quarterly newsletters (105 participants), a group that received face-to-face intervention (105), and a group that received Internet-based intervention (104). The content of the programs in the two intervention groups was the same, emphasizing daily self-weighing and self-regulation, as was the frequency of contact with the groups. The primary outcome was weight gain over a period of 18 months.
The mean (+/-SD) weight gain was 2.5+/-6.7 kg in the face-to-face group, 4.7+/-8.6 kg in the Internet group, and 4.9+/-6.5 kg in the control group, with a significant difference between the face-to-face group and the control group (2.4 kg; 95% confidence interval CI, 0.002 to 10.8; P=0.05). The proportion of participants who regained 2.3 kg or more over the 18-month period was significantly higher in the control group (72.4%) than in the face-to-face group (45.7%; absolute difference, 27%; 95% CI, 14 to 39; P<0.001) or the Internet group (54.8%; absolute difference, 18%; 95% CI, 5 to 30; P=0.008). Daily self-weighing increased in both intervention groups and was associated with a decreased risk of regaining 2.3 kg or more (P<0.001).
As compared with receiving quarterly newsletters, a self-regulation program based on daily weighing improved maintenance of weight loss, particularly when delivered face to face. (ClinicalTrials.gov number, NCT00067145 ClinicalTrials.gov.)
Drugs targeting microtubules rely on the mitotic checkpoint to arrest cell proliferation. The prolonged mitotic arrest induced by such drugs is followed by a G1 arrest. Here, we follow for several ...weeks the fate of G1-arrested human cells after treatment with nocodazole. We find that a small fraction of cells escapes from the arrest and resumes proliferation. These escaping cells experience reduced DNA damage and p21 activation. Cells surviving treatment are enriched for anti-apoptotic proteins, including Triap1. Increasing Triap1 levels allows cells to survive the first treatment with reduced DNA damage and lower levels of p21; accordingly, decreasing Triap1 re-sensitizes cells to nocodazole. We show that Triap1 upregulation leads to the retention of cytochrome c in the mitochondria, opposing the partial activation of caspases caused by nocodazole. In summary, our results point to a potential role of Triap1 upregulation in the emergence of resistance to drugs that induce prolonged mitotic arrest.
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•Cells arrested by nocodazole accumulate DNA damage but recover growth after G1 arrest•When treated for a second time, cells accumulate less DNA damage and recover faster•The expression of about 100 proteins, including Triap1, is altered•Increased Triap1 expression decreases DNA damage and accounts for the faster recovery
Antimitotic drugs impair microtubule dynamics and cause cells to arrest in mitosis or die due to DNA damage. Pavani et al. show that a fraction of cells escapes the arrest and restores proliferation and, when treated a second time, can repress cell death and decrease the extent of DNA damage.
The PIDDosome is a Caspase-2-activating platform assembling in response to centrosome amplification or genotoxic stress. We have recently shown that both stimuli depend on ANKRD26 (ankyrin repeat ...domain-containing protein 26)-mediated localization of PIDD1 (p53-inducible protein with death domain) at the centrosome, demonstrating how this organelle can directly influence cell fate.
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