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Siegel JH, Rivkind AI, Dalal S, Goodarzi S. Early physiologic predictors of injury severity and death in blunt multiple trauma. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 1990; 125:498-508. [PMID: 2322117 DOI: 10.1001/archsurg.1990.01410160084019] [Citation(s) in RCA: 194] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The importance of admission physiological and biochemical variables was modeled on data from 185 patients with blunt liver trauma with regard to their significance in prediction of mortality. The variables used were admission Glasgow Coma Score, base excess (or deficit), arterial lactate, Injury Severity Score, and initial 24-hour volume of blood required for replacement. Each variable was modeled as a predictor of survival alone and in combination, using a linear logistic model. In any two-variable combination, Glasgow Coma Score had a high likelihood ratio for prediction representing the influence of brain injury. But as a single variable reflecting the probability of death, both base excess (LD50 = -11.8 mmol/L) and initial 24-hour volume of blood (LD50 = 5.4 L) were highly significant. A combined logistic model of admission Glasgow Coma Score and base excess had the greatest likelihood of accurate prediction of outcome: P death = e lambda/l + e lambda; where lambda = -0.21(Glasgow Coma Score) -0.147(base excess) + 0.285. Testing of this predictive model on data from 323 additional patients with multiple trauma who had pelvic fracture as their index injury also showed it to be a highly significant early predictor of outcome.
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Liu Y, Chen JJ, Gao Q, Dalal S, Hong Y, Mansur CP, Band V, Androphy EJ. Multiple functions of human papillomavirus type 16 E6 contribute to the immortalization of mammary epithelial cells. J Virol 1999; 73:7297-307. [PMID: 10438818 PMCID: PMC104255 DOI: 10.1128/jvi.73.9.7297-7307.1999] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The E6 proteins from cervical cancer-associated human papillomavirus (HPV) types such as HPV type 16 (HPV-16) induce proteolysis of the p53 tumor suppressor protein through interaction with E6-AP. We have previously shown that human mammary epithelial cells (MECs) immortalized by HPV-16 E6 display low levels of p53. HPV-16 E6 as well as other cancer-related papillomavirus E6 proteins also binds the cellular protein E6BP (ERC-55). To explore the potential functional significance of these interactions, we created and analyzed a series of E6 mutants for their ability to interact with E6-AP, p53, and E6BP in vitro. While there was a similar pattern of binding among these E6 targets, a subset of mutants differentiated E6-AP binding, p53 binding, and p53 degradation activities. These results demonstrated that E6 binding to E6-AP is not sufficient for binding to p53 and that E6 binding to p53 is not sufficient for inducing p53 degradation. The in vivo activity of these HPV-16 E6 mutants was tested in MECs. In agreement with the in vitro results, most of these p53 degradation-defective E6 mutants were unable to reduce the p53 level in early-passage MECs. Interestingly, several mutants that showed severely reduced ability for interacting with E6-AP, p53, and E6BP in vitro efficiently immortalized MECs. These immortalized cells exhibited low p53 levels at late passage. Furthermore, mutants defective for p53 degradation but able to immortalize MECs were also identified, and the immortal cells retained normal levels of p53 protein. These results imply that multiple functions of HPV-16 E6 contribute to MEC immortalization.
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26 |
161 |
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Dalal S, Balasubramanian S, Regan L. Protein alchemy: changing beta-sheet into alpha-helix. NATURE STRUCTURAL BIOLOGY 1997; 4:548-52. [PMID: 9228947 DOI: 10.1038/nsb0797-548] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
For most proteins the amino acid sequence determines the tertiary structure. The relative importance of the individual amino acids in specifying the fold, however, remains unclear. To highlight this, Creamer and Rose put forth the 'Paracelsus challenge': Design a protein with 50% sequence identity to a protein with a different fold. We have met this challenge by designing a sequence which retains 50% identity to a predominantly beta-sheet protein, but which now adopts a four helix bundle conformation and possesses the attributes of a native protein. Our results emphasize that a subset of the amino acid sequence is sufficient to specify a fold, and have implications both for structure prediction and design.
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Band V, Dalal S, Delmolino L, Androphy EJ. Enhanced degradation of p53 protein in HPV-6 and BPV-1 E6-immortalized human mammary epithelial cells. EMBO J 1993; 12:1847-52. [PMID: 8387914 PMCID: PMC413405 DOI: 10.1002/j.1460-2075.1993.tb05833.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Normal mammary epithelial cells are efficiently immortalized by the E6 gene of human papillomavirus (HPV)-16, a virus commonly associated with cervical cancers. Surprisingly, introduction of the E6 gene from HPV-6, which is rarely found in cervical cancer, or bovine papillomavirus (BPV)-1, into normal mammary cells resulted in the generation of immortal cell lines. The establishment of HPV-6 and BPV-1 E6-immortalized cells was less efficient and required a longer period in comparison to HPV-16 E6. These HPV-6- and BPV-1 E6-immortalized cells demonstrated dramatically reduced levels of p53 protein by immunoprecipitation. While the half-life of p53 protein in normal mammary epithelial cells was approximately 3 h, it was reduced to approximately 15 min in all the E6-immortalized cells. These results demonstrate that the E6 genes of both high-risk and low-risk papilloma viruses immortalize human mammary epithelial cells and induce a marked degradation of p53 protein in vivo.
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99 |
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Hamilton SR, Stapleton D, O'Donnell JB, Kung JT, Dalal SR, Kemp BE, Witters LA. An activating mutation in the gamma1 subunit of the AMP-activated protein kinase. FEBS Lett 2001; 500:163-8. [PMID: 11445078 DOI: 10.1016/s0014-5793(01)02602-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The AMP-activated protein kinase (AMPK) is a heterotrimeric protein composed of a catalytic alpha subunit and two regulatory subunits, beta and gamma. The gamma subunit is essential for enzyme activity by virtue of its binding to the C-terminus of the alpha subunit and appears to play some role in the determination of AMP sensitivity. We demonstrate that a gamma1R70Q mutation causes a marked increase in AMPK activity and renders it largely AMP-independent. This activation is associated with increased phosphorylation of the alpha subunit activation loop T172. These in vitro characteristics of AMPK are also reflected in increased intracellular phosphorylation of one of its major substrates, acetyl-CoA carboxylase. These data illustrate the importance of the gamma1 subunit in the regulation of AMPK and its modulation by AMP.
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Dev R, Bruera E, Dalal S. Insulin resistance and body composition in cancer patients. Ann Oncol 2019; 29 Suppl 2:ii18-ii26. [PMID: 29506229 DOI: 10.1093/annonc/mdx815] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cancer cachexia, weight loss with altered body composition, is a multifactorial syndrome propagated by symptoms that impair caloric intake, tumor byproducts, chronic inflammation, altered metabolism, and hormonal abnormalities. Cachexia is associated with reduced performance status, decreased tolerance to chemotherapy, and increased mortality in cancer patients. Insulin resistance as a consequence of tumor byproducts, chronic inflammation, and endocrine dysfunction has been associated with weight loss in cancer patients. Insulin resistance in cancer patients is characterized by increased hepatic glucose production and gluconeogenesis, and unlike type 2 diabetes, normal fasting glucose with high, normal or low levels of insulin. Cancer cachexia results in altered body composition with the loss of lean muscle mass with or without the loss of adipose tissue. Alteration in visceral adiposity, accumulation of intramuscular adipose tissue, and secretion of adipocytokines from adipose cells may play a role in promoting the metabolic derangements associated with cachexia including a proinflammatory environment and insulin resistance. Increased production of ghrelin, testosterone deficiency, and low vitamin D levels may also contribute to altered metabolism of glucose. Cancer cachexia cannot be easily reversed by standard nutritional interventions and identifying and treating cachexia at the earliest stage of development is advocated. Experts advocate for multimodal therapy to address symptoms that impact caloric intake, reduce chronic inflammation, and treat metabolic and endocrine derangements, which propagate the loss of weight. Treatment of insulin resistance may be a critical component of multimodal therapy for cancer cachexia and more research is needed.
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Review |
6 |
88 |
7
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Khodyakov D, Hempel S, Rubenstein L, Shekelle P, Foy R, Salem-Schatz S, O'Neill S, Danz M, Dalal S. Conducting online expert panels: a feasibility and experimental replicability study. BMC Med Res Methodol 2011; 11:174. [PMID: 22196011 PMCID: PMC3313865 DOI: 10.1186/1471-2288-11-174] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 12/23/2011] [Indexed: 01/10/2023] Open
Abstract
Background This paper has two goals. First, we explore the feasibility of conducting online expert panels to facilitate consensus finding among a large number of geographically distributed stakeholders. Second, we test the replicability of panel findings across four panels of different size. Method We engaged 119 panelists in an iterative process to identify definitional features of Continuous Quality Improvement (CQI). We conducted four parallel online panels of different size through three one-week phases by using the RAND's ExpertLens process. In Phase I, participants rated potentially definitional CQI features. In Phase II, they discussed rating results online, using asynchronous, anonymous discussion boards. In Phase III, panelists re-rated Phase I features and reported on their experiences as participants. Results 66% of invited experts participated in all three phases. 62% of Phase I participants contributed to Phase II discussions and 87% of them completed Phase III. Panel disagreement, measured by the mean absolute deviation from the median (MAD-M), decreased after group feedback and discussion in 36 out of 43 judgments about CQI features. Agreement between the four panels after Phase III was fair (four-way kappa = 0.36); they agreed on the status of five out of eleven CQI features. Results of the post-completion survey suggest that participants were generally satisfied with the online process. Compared to participants in smaller panels, those in larger panels were more likely to agree that they had debated each others' view points. Conclusion It is feasible to conduct online expert panels intended to facilitate consensus finding among geographically distributed participants. The online approach may be practical for engaging large and diverse groups of stakeholders around a range of health services research topics and can help conduct multiple parallel panels to test for the reproducibility of panel conclusions.
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Research Support, U.S. Gov't, Non-P.H.S. |
14 |
74 |
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Dalal S, Gao Q, Androphy EJ, Band V. Mutational analysis of human papillomavirus type 16 E6 demonstrates that p53 degradation is necessary for immortalization of mammary epithelial cells. J Virol 1996; 70:683-8. [PMID: 8551603 PMCID: PMC189867 DOI: 10.1128/jvi.70.2.683-688.1996] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have previously demonstrated that normal human mammary epithelial cells (MECs) are efficiently immortalized by human papillomavirus type 16 (HPV16) E6. HPV16 E6 binds to and induces p53 degradation in vitro and induces a marked reduction of p53 protein in MECs. Low-risk HPV6 E6 is defective for p53 binding and degradation in vitro but immortalized MECs at low efficiency. The HPV6 E6-immortalized MECs had markedly reduced levels of p53. To directly investigate whether the ability of HPV16 E6 to stimulate p53 degradation is required for E6-induced immortalization, a series of HPV16 E6 mutants were analyzed for the ability to bind and degrade p53 in vitro, induce a reduction in p53 levels in vivo, and immortalize MECs. We observed that one set of mutants efficiently immortalized MECs, caused a reduction in p53 levels in vivo, and degraded p53 in vitro. Other mutants immortalized MECs with low efficiency and either induced p53 degradation at low levels or were unable to induce p53 degradation in vitro; however, all of the immortal clones displayed low levels of p53. A third class of mutants did not immortalize MECs and failed to induce a reduction in p53 levels in vivo or degrade p53 in vitro. These results demonstrate that a reduction in p53 protein levels due to enhanced degradation is essential for MEC immortalization by HPV16 E6.
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Abstract
Recent research has investigated drug combinations that enhance the analgesic effectiveness of their component substances. Many studies have examined the combination of opioids and psychostimulant drugs, such as amphetamine and methylphenidate. Despite the positive results reported in the literature, this combination is rarely used in clinical practice. The purpose of this paper is to review the literature on the opioid-amphetamine combination. Experiments with animal and human subjects provide convincing evidence that d-amphetamine or methylphenidate potentiate the analgesic effects of morphine. Psychostimulant drugs have been shown in animal studies to possess intrinsic analgesic properties and to have the ability to enhance the analgesic properties of opioids when both types of drugs are given in combination. Studies with human subjects have confirmed the enhancement of opioid analgesia by amphetamines and, in addition, have demonstrated that psychostimulant drugs produce a decrease in somnolence and an increase in general cognitive abilities. The greater cognitive alertness, moreover, allows the use of larger opioid doses, which can produce a substantial increase in analgesia. These results indicate another possible method to enhance the quality of life in patients with difficult pain problems. Although the enhanced cognitive effects are well established, the effects on pain need further study to determine the mechanisms of action and the drug combinations and administration patterns that would maximize their effects.
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Review |
27 |
68 |
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Shetty KD, Dalal SR. Using information mining of the medical literature to improve drug safety. J Am Med Inform Assoc 2011; 18:668-74. [PMID: 21546507 DOI: 10.1136/amiajnl-2011-000096] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE Prescription drugs can be associated with adverse effects (AEs) that are unrecognized despite evidence in the medical literature, as shown by rofecoxib's late recall in 2004. We assessed whether applying information mining to PubMed could reveal major drug-AE associations if articles testing whether drugs cause AEs are over-represented in the literature. DESIGN MEDLINE citations published between 1949 and September 2009 were retrieved if they mentioned one of 38 drugs and one of 55 AEs. A statistical document classifier (using MeSH index terms) was constructed to remove irrelevant articles unlikely to test whether a drug caused an AE. The remaining relevant articles were analyzed using a disproportionality analysis that identified drug-AE associations (signals of disproportionate reporting) using step-up procedures developed to control the familywise type I error rate. MEASUREMENTS Sensitivity and positive predictive value (PPV) for empirical drug-AE associations as judged against drug-AE associations subject to FDA warnings. RESULTS In testing, the statistical document classifier identified relevant articles with 81% sensitivity and 87% PPV. Using data filtered by the statistical document classifier, base-case models showed 64.9% sensitivity and 42.4% PPV for detecting FDA warnings. Base-case models discovered 54% of all detected FDA warnings using literature published before warnings. For example, the rofecoxib-heart disease association was evident using literature published before 2002. Analyses incorporating literature mentioning AEs common to the drug class of interest yielded 71.4% sensitivity and 40.7% PPV. CONCLUSIONS Results from large-scale literature retrieval and analysis (literature mining) compared favorably with and could complement current drug safety methods.
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Research Support, Non-U.S. Gov't |
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58 |
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Rubenstein L, Khodyakov D, Hempel S, Danz M, Salem-Schatz S, Foy R, O'Neill S, Dalal S, Shekelle P. How can we recognize continuous quality improvement? Int J Qual Health Care 2013; 26:6-15. [PMID: 24311732 PMCID: PMC3914565 DOI: 10.1093/intqhc/mzt085] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Objective Continuous quality improvement (CQI) methods are foundational approaches to improving healthcare delivery. Publications using the term CQI, however, are methodologically heterogeneous, and labels other than CQI are used to signify relevant approaches. Standards for identifying the use of CQI based on its key methodological features could enable more effective learning across quality improvement (QI) efforts. The objective was to identify essential methodological features for recognizing CQI. Design Previous work with a 12-member international expert panel identified reliably abstracted CQI methodological features. We tested which features met rigorous a priori standards as essential features of CQI using a three-phase online modified-Delphi process. Setting Primarily United States and Canada. Participants 119 QI experts randomly assigned into four on-line panels. Intervention(s) Participants rated CQI features and discussed their answers using online, anonymous and asynchronous discussion boards. We analyzed ratings quantitatively and discussion threads qualitatively. Main outcome measure(s) Panel consensus on definitional CQI features. Results Seventy-nine (66%) panelists completed the process. Thirty-three completers self-identified as QI researchers, 18 as QI practitioners and 28 as both equally. The features ‘systematic data guided activities,’ ‘designing with local conditions in mind’ and ‘iterative development and testing’ met a priori standards as essential CQI features. Qualitative analyses showed cross-cutting themes focused on differences between QI and CQI. Conclusions We found consensus among a broad group of CQI researchers and practitioners on three features as essential for identifying QI work more specifically as ‘CQI.’ All three features are needed as a minimum standard for recognizing CQI methods.
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Research Support, Non-U.S. Gov't |
12 |
56 |
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Rodrigues VS, Milanski M, Fagundes JJ, Torsoni AS, Ayrizono MLS, Nunez CEC, Dias CB, Meirelles LR, Dalal S, Coy CSR, Velloso LA, Leal RF. Serum levels and mesenteric fat tissue expression of adiponectin and leptin in patients with Crohn's disease. Clin Exp Immunol 2013; 170:358-64. [PMID: 23121676 DOI: 10.1111/j.1365-2249.2012.04660.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Crohn's disease (CD) is characterized by inflammation and an aetiology that is still unknown. Hypertrophy of mesenteric fat is a reflection of disease activity, as this fat covers the entire length of the affected area. Adipocytes synthesize leptin and adiponectin, adipocytokines responsible for pro- and anti-inflammatory effects. Therefore, we evaluated serum levels of adiponectin and leptin, as well as mesenteral expression of adiponectin in active CD and those in remission. Sixteen patients with ileocaecal CD followed at the Outpatient Clinic, Coloproctology Unit of University of Campinas Clinical Hospital, participated in the study. Analysis of serum adiponectin and leptin by enzyme-linked immunosorbent assay was performed in patients with active CD (ACD group), remission CD (RCD group) and in six healthy controls. Ten patients with active ileocaecal CD (FCD group) and eight patients with non-inflammatory disease selected for surgery were also studied. The specimens were snap-frozen and the expression of adiponectin was determined by immunoblot of protein extracts. Serum C-reactive protein levels were higher in the ACD group when compared to the others and no difference of body mass index was observed between the groups. Serum adiponectin was lower in the ACD group when compared to control, but no differences were seen when comparing the ACD and RCD groups. Mesenteric adiponectin expression was lower in the FCD group when compared to the FC group. Serum leptin was similar in all groups. The lower levels of serum and mesenteric adiponectin in active CD suggest a defective regulation of anti-inflammatory pathways in CD pathogenesis.
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Research Support, Non-U.S. Gov't |
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46 |
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Claassen CA, Pearson JL, Khodyakov D, Satow PM, Gebbia R, Berman AL, Reidenberg DJ, Feldman S, Molock S, Carras MC, Lento RM, Sherrill J, Pringle B, Dalal S, Insel TR. Reducing the burden of suicide in the U.S.: the aspirational research goals of the National Action Alliance for Suicide Prevention Research Prioritization Task Force. Am J Prev Med 2014; 47:309-14. [PMID: 24750971 PMCID: PMC5712425 DOI: 10.1016/j.amepre.2014.01.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 12/09/2013] [Accepted: 01/08/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND The National Action Alliance for Suicide Prevention Research Prioritization Task Force (RPTF) has created a prioritized national research agenda with the potential to rapidly and substantially reduce the suicide burden in the U.S. if fully funded and implemented. PURPOSE Viable, sustainable scientific research agendas addressing challenging public health issues such as suicide often need to incorporate perspectives from multiple stakeholder groups (e.g., researchers, policymakers, and other end-users of new knowledge) during an agenda-setting process. The Stakeholder Survey was a web-based survey conducted and analyzed in 2011-2012 to inform the goal-setting step in the RPTF agenda development process. The survey process, and the final list of "aspirational" research goals it produced, are presented here. METHODS Using a modified Delphi process, diverse constituent groups generated and evaluated candidate research goals addressing pressing suicide prevention research needs. RESULTS A total of 716 respondents representing 49 U.S. states and 18 foreign countries provided input that ultimately produced 12 overarching, research-informed aspirational goals aimed at reducing the U.S. suicide burden. Highest-rated goals addressed prevention of subsequent suicidal behavior after an initial attempt, strategies to retain patients in care, improved healthcare provider training, and generating care models that would ensure accessible treatment. CONCLUSIONS The Stakeholder Survey yielded widely valued research targets. Findings were diverse in focus, type, and current phase of research development but tended to prioritize practical solutions over theoretical advancement. Other complex public health problems requiring input from a broad-based constituency might benefit from web-based tools that facilitate such community input.
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Abstract
Protein architecture involves two main secondary structural classes: alpha helices and beta sheets. Some natural proteins alter their fold in response to changes in solution conditions or as a consequence of mutation. Here, we discuss recent attempts to induce such conformational changes by design: specifically, the motivation and success of efforts to change one protein fold into a different one in response to the 'Paracelsus Challenge'. The results of such efforts may provide a better understanding of the processes that underlie conformational plasticity in proteins.
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Review |
27 |
41 |
15
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Dalal S, Parkin SM, Homer-Vanniasinkam S, Nicolaou A. Effect of homocysteine on cytokine production by human endothelial cells and monocytes. Ann Clin Biochem 2004; 40:534-41. [PMID: 14503991 DOI: 10.1258/000456303322326452] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Hyperhomocysteinaemia is an independent risk factor in the development of cardiovascular disease. Although homocysteine has been shown to affect endothelial cell function, the mechanisms by which it induces disease states are still poorly understood. Here, we report the ability of homocysteine to influence inflammatory cytokine/chemokine production by human saphenous vein endothelial cells, peripheral blood monocytes and monocyte-derived macrophages. METHODS Human saphenous vein endothelial cells, peripheral blood monocytes and monocyte-derived macrophages were treated with homocysteine (0.1-5 mmol/L) for 4 and/or 24h. Tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and IL-8 production was measured in the cell culture media using commercially available enzyme-linked immunosorbent assays. RESULTS Interleukin-6 production by human saphenous vein endothelial cells was significantly stimulated following a 24-h treatment with homocysteine, whilst IL-8 concentrations were inhibited after both 4- and 24-h treatments. Homocysteine was also found to stimulate IL-1beta production by human peripheral blood monocytes and TNF-alpha production by monocyte-derived macrophages. CONCLUSIONS Overall, results from this study suggest that homocysteine alters the profile of cytokine/chemokine production by endothelial cells and macrophages. This altered profile may be important in the inflammatory events that initiate or enhance the development of atherosclerotic lesions.
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Journal Article |
21 |
40 |
16
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Dalal S, Regan L. Understanding the sequence determinants of conformational switching using protein design. Protein Sci 2000; 9:1651-9. [PMID: 11045612 PMCID: PMC2144699 DOI: 10.1110/ps.9.9.1651] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
An important goal of protein design is to understand the forces that stabilize a particular fold in preference to alternative folds. Here, we describe an extension of earlier studies in which we successfully designed a stable, native-like helical protein that is 50% identical in sequence to a predominantly beta-sheet protein, the B1 domain of Streptococcal IgG-binding protein G. We report the characteristics of a series of variants of our original design that have even higher sequence identity to the B1 domain. Their properties illustrate the extent to which protein stability and conformation can be modulated through careful manipulation of key amino acid residues. Our results have implications for understanding conformational change phenomena of central biological importance and in probing the malleability of the sequence/structure relationship.
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research-article |
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38 |
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Review |
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35 |
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Dalal SR, Fowlkes EB, Hoadley B. Risk Analysis of the Space Shuttle: Pre-Challenger Prediction of Failure. J Am Stat Assoc 1989. [DOI: 10.2307/2290069] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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36 |
28 |
20
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Jain S, Hasan S, Vyas N, Shah N, Dalal S. Pleomorphic Adenoma of the Parotid Gland: Report of a Case With Review of Literature. Ethiop J Health Sci 2016; 25:189-94. [PMID: 26124628 PMCID: PMC4478272 DOI: 10.4314/ejhs.v25i2.13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Pleomorphic adenomas are benign salivary gland tumors, which predominantly affect the superficial lobe of the parotid gland. The “pleomorphic” nature of the tumor can be explained on the basis of its epithelial and connective tissue origin. The tumor has a female predilection between 30–50 years of age. Slowly progressing asymptomatic swelling is the usual presentation of the tumor. Surgical excision of the tumor mass forms the mainstay of treatment, with utmost care taken to preserve the facial nerve. Case Details This case report aims to throw light on an interesting case of pleomorphic adenoma of the parotid gland in a 50 years old female patient. The patient presented with a slowly progressing asymptomatic swelling on the left side of the face. There is also a special emphasis to a detailed review of literature. Conclusion Salivary gland neoplasms can occur at any site where salivary tissue is present. Pleomorphic adenoma is the commonest salivary gland tumor characterized by diverse histomorphological features. Early diagnosis and treatment plan entails thorough history taking, clinical examination, coupled with radiographic and histopathological findings.
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Review |
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Dalal S, Yu AW, Gupta DK, Kar PM, Ing TS, Daugirdas JT. L-lactate high-efficiency hemodialysis: hemodynamics, blood gas changes, potassium/phosphorus, and symptoms. Kidney Int 1990; 38:896-903. [PMID: 2266673 DOI: 10.1038/ki.1990.288] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hemodynamic changes were measured during high-efficiency hemodialysis (HEHD) using three dialysis solutions: L-lactate (46 mM), bicarbonate (35 mM + 4 mM acetate), and acetate (39 mM). Cardiac output was determined by changes in thoracic electrical bioimpedance. Although there appeared to be subtle differences in hemodynamic response to L-lactate versus bicarbonate, the blood pressure, cardiac output, and total peripheral resistance were affected less with either of these solutions than with acetate. In particular, neither L-lactate nor bicarbonate HEHD were associated with a change in cardiac output, whereas with acetate HEHD a marked (22%) increase in cardiac output was seen concurrently with a moderate fall in blood pressure and TPR. Both acetate and L-lactate HEHD were associated with hypoxemia, whereas with bicarbonate HEHD the PO2 did not change. With L-lactate HEHD, correction of pH and plasma HCO3 concentrations was delayed but these values were not significantly different from those obtained with bicarbonate HEHD by one hour after dialysis. Potassium removal was comparable with the three dialysis solutions. Phosphorus removal with L-lactate tended to be slightly less than with bicarbonate, but not less than with acetate. Our results suggest that L-lactate (46 mM) dialysis solution may be a suitable alternative to acetate for HEHD, being associated with a hemodynamic profile that is similar to that of bicarbonate and better than that of acetate. Our results further suggest that the hypoxemia associated with the use of acetate dialysis solution is not intrinsic to acetate, but is due either to a low dialysis solution PCO2 level or to accelerated consumption of oxygen during substrate metabolism.
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Clinical Trial |
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Khodyakov D, Savitsky TD, Dalal S. Collaborative learning framework for online stakeholder engagement. Health Expect 2016; 19:868-82. [PMID: 26295924 PMCID: PMC5049448 DOI: 10.1111/hex.12383] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2015] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Public and stakeholder engagement can improve the quality of both research and policy decision making. However, such engagement poses significant methodological challenges in terms of collecting and analysing input from large, diverse groups. OBJECTIVE To explain how online approaches can facilitate iterative stakeholder engagement, to describe how input from large and diverse stakeholder groups can be analysed and to propose a collaborative learning framework (CLF) to interpret stakeholder engagement results. METHODS We use 'A National Conversation on Reducing the Burden of Suicide in the United States' as a case study of online stakeholder engagement and employ a Bayesian data modelling approach to develop a CLF. RESULTS Our data modelling results identified six distinct stakeholder clusters that varied in the degree of individual articulation and group agreement and exhibited one of the three learning styles: learning towards consensus, learning by contrast and groupthink. Learning by contrast was the most common, or dominant, learning style in this study. CONCLUSION Study results were used to develop a CLF, which helps explore multitude of stakeholder perspectives; identifies clusters of participants with similar shifts in beliefs; offers an empirically derived indicator of engagement quality; and helps determine the dominant learning style. The ability to detect learning by contrast helps illustrate differences in stakeholder perspectives, which may help policymakers, including Patient-Centered Outcomes Research Institute, make better decisions by soliciting and incorporating input from patients, caregivers, health-care providers and researchers. Study results have important implications for soliciting and incorporating input from stakeholders with different interests and perspectives.
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O'Connor SJ, Forsyth PD, Dalal S, Evans PA, Short MA, Shiach C, Jack AS, Morgan GJ. The rapid diagnosis of acute promyelocytic leukaemia using PML (5E10) monoclonal antibody. Br J Haematol 1997; 99:597-604. [PMID: 9401072 DOI: 10.1046/j.1365-2141.1997.4613266.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Acute promyelocytic leukaemia (APL) is characterized cytogenetically by t(15;17)(q22:q21) which results in the production of a PML/RAR alpha fusion protein. Detection of the translocation or the fusion gene product is required for objective diagnosis of APL. This can be accomplished by conventional cytogenetic methods, fluorescence in situ hybridization or RT-PCR. Such techniques are time consuming and not universally available. The intracellular distribution of the PML protein in promyelocytes is characteristically altered in APL and this can be detected by immunocytochemistry. We have assessed two immunocytochemical methods, immunofluorescence and alkaline phosphatase-anti-alkaline phosphatase staining (APAAP), with regard to sensitivity, specificity and rapidity of diagnosis. 85 patients with AML including 15 cases of APL were studied. Immunofluorescence PML detection was concordant with RT-PCR for t(15:17) in 14/15 (93.3%) cases with no false positives. The negative APL case in our series was a patient with a 5' PML breakpoint who did not express the reciprocal t(17;15) fusion product. APAAP was concordant in only 6/13 (46%) APL cases with one false positive. In conclusion, immunofluorescent localization of PML using 5E10 monoclonal antibody is a rapid, sensitive and specific diagnostic tool for APL.
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Abstract
Recent research has shown that the psychostimulant drug dextroamphetamine can increase the analgesia produced by opioids. Despite the strong, positive results in human clinical subjects and in animals, this combination is rarely used in clinical practice. The purpose of this paper is to investigate whether the psychostimulant drug methylphenidate (MP) can potentiate morphine analgesia in the rat formalin test, and to compare its effectiveness to that of dextroamphetamine (AMP). The formalin test was used because its long-lasting pain of moderate intensity resembles human clinical pain. Two different drug administration times were used to observe whether the early phase of the formalin response would be differentially affected by the drugs. At Drug Administration Time 1, rats received morphine 30 min prior to the formalin injection (-30 min) and MP or AMP 20 min prior to the formalin injection (-20 min). At Drug Administration Time 2, rats received morphine 10 min prior to the formalin injection (-10 min) and MP or AMP immediately prior to the formalin injection (0 min). All drugs were given subcutaneously. The results indicate that low doses of MP or AMP potentiate the analgesic effects of morphine. The clinical value of these drug combinations merits further investigation in animals and in humans.
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Schwitters A, Kaggwa M, Omiel P, Nagadya G, Kisa N, Dalal S. Tuberculosis incidence and treatment completion among Ugandan prison inmates. Int J Tuberc Lung Dis 2015; 18:781-6. [PMID: 24902552 DOI: 10.5588/ijtld.13.0934] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Uganda Prisons Service (UPS) is responsible for the health of approximately 32 500 inmates in 233 prisons. In 2008 a rapid UPS assessment estimated TB prevalence at 654/100 000, three times that of the general population (183/100 000). Although treatment programs exist, little is known about treatment completion in sub-Saharan African prisons. METHODS We conducted a retrospective study of Ugandan prisoners diagnosed with TB from June 2011 to November 2012. We analyzed TB diagnosis, TB-HIV comorbidity and treatment completion from national registers and tracked prison transfers and releases. RESULTS A total of 469 prisoners were diagnosed with TB over the 1.5-year period (incidence 955/100 000 person-years). Of 466 prisoners starting treatment, 48% completed treatment, 43% defaulted, 5% died and 4% were currently on treatment. During treatment, 12% of prisoners remaining in the same prison defaulted, 53% of transfers defaulted and 81% of those released were lost to follow-up. The odds of defaulting were 8.36 times greater among prisoners who were transferred during treatment. CONCLUSIONS TB incidence and treatment default are high among Ugandan prisoners. Strategies to improve treatment completion and prevent multidrug resistance could include avoiding transfer of TB patients, improving communications between prisons to ensure treatment follow-up after transfer and facilitating transfer to community clinics for released prisoners.
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Research Support, U.S. Gov't, P.H.S. |
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