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Zhang A, Altuvia S, Tiwari A, Argaman L, Hengge-Aronis R, Storz G. The OxyS regulatory RNA represses rpoS translation and binds the Hfq (HF-I) protein. EMBO J 1998; 17:6061-8. [PMID: 9774349 PMCID: PMC1170932 DOI: 10.1093/emboj/17.20.6061] [Citation(s) in RCA: 335] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The OxyS regulatory RNA integrates the adaptive response to hydrogen peroxide with other cellular stress responses and protects against DNA damage. Among the OxyS targets is the rpoS-encoded sigma(s) subunit of RNA polymerase. Sigma(s) is a central regulator of genes induced by osmotic stress, starvation and entry into stationary phase. We examined the mechanism whereby OxyS represses rpoS expression and found that the OxyS RNA inhibits translation of the rpoS message. This repression is dependent on the hfq-encoded RNA-binding protein (also denoted host factor I, HF-I). Co-immunoprecipitation and gel mobility shift experiments revealed that the OxyS RNA binds Hfq, suggesting that OxyS represses rpoS translation by altering Hfq activity.
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Abstract
BACKGROUND Acute compartment syndrome is both a limb- and life-threatening emergency that requires prompt treatment. To avoid a delay in diagnosis requires vigilance and, if necessary, intracompartmental pressure measurement. This review encompasses both limb and abdominal compartment syndrome, including aetiology, diagnosis, treatment and outcome. METHODS A Pubmed and Cochrane database search was performed. Other articles were cross-referenced. RESULTS AND CONCLUSION Diagnosis of limb compartment syndrome is based on clinical vigilance and repeated examination. Many techniques exist for tissue pressure measurement but they are indicated only in doubtful cases, the unconscious or obtunded patient, and children. However, monitoring of pressure has no harmful effect and may allow early fasciotomy, although the intracompartmental pressure threshold for such an undertaking is still unclear. Abdominal compartment syndrome requires measurement of intra-abdominal pressure because clinical diagnosis is difficult. Treatment is by abdominal decompression and secondary closure. Both types of compartment syndrome require prompt treatment to avoid significant sequelae.
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Review |
23 |
199 |
3
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Altuvia S, Zhang A, Argaman L, Tiwari A, Storz G. The Escherichia coli OxyS regulatory RNA represses fhlA translation by blocking ribosome binding. EMBO J 1998; 17:6069-75. [PMID: 9774350 PMCID: PMC1170933 DOI: 10.1093/emboj/17.20.6069] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OxyS is a small untranslated RNA which is induced in response to oxidative stress in Escherichia coli. This novel RNA acts as a global regulator to activate or repress the expression of as many as 40 genes, including the fhlA-encoded transcriptional activator and the rpoS-encoded sigma(s) subunit of RNA polymerase. Deletion analysis of OxyS showed that different domains of the small RNA are required for the regulation of fhlA and rpoS. We examined the mechanism of OxyS repression of fhlA and found that the OxyS RNA inhibits fhlA translation by pairing with a short sequence overlapping the Shine-Dalgarno sequence, thereby blocking ribosome binding/translation.
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173 |
4
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Pathak Y, Shukla PK, Tiwari A, Stalin S, Singh S, Shukla PK. Deep Transfer Learning Based Classification Model for COVID-19 Disease. Ing Rech Biomed 2020; 43:87-92. [PMID: 32837678 PMCID: PMC7238986 DOI: 10.1016/j.irbm.2020.05.003] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/10/2020] [Accepted: 05/15/2020] [Indexed: 12/15/2022]
Abstract
The COVID-19 infection is increasing at a rapid rate, with the availability of limited number of testing kits. Therefore, the development of COVID-19 testing kits is still an open area of research. Recently, many studies have shown that chest Computed Tomography (CT) images can be used for COVID-19 testing, as chest CT images show a bilateral change in COVID-19 infected patients. However, the classification of COVID-19 patients from chest CT images is not an easy task as predicting the bilateral change is defined as an ill-posed problem. Therefore, in this paper, a deep transfer learning technique is used to classify COVID-19 infected patients. Additionally, a top-2 smooth loss function with cost-sensitive attributes is also utilized to handle noisy and imbalanced COVID-19 dataset kind of problems. Experimental results reveal that the proposed deep transfer learning-based COVID-19 classification model provides efficient results as compared to the other supervised learning models.
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Journal Article |
5 |
155 |
5
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Vergidis K, Tiwari A, Majeed B. Business Process Analysis and Optimization: Beyond Reengineering. ACTA ACUST UNITED AC 2008. [DOI: 10.1109/tsmcc.2007.905812] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17 |
142 |
6
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Tiwari A, Leung WC, Leung TW, Humphreys J, Parker B, Ho PC. A randomised controlled trial of empowerment training for Chinese abused pregnant women in Hong Kong. BJOG 2005; 112:1249-56. [PMID: 16101604 DOI: 10.1111/j.1471-0528.2005.00709.x] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To evaluate the effectiveness of an empowerment intervention in reducing intimate partner violence (IPV) and improving health status. DESIGN Randomised controlled trial. SETTING Antenatal clinic in a public hospital in Hong Kong. SAMPLE One hundred and ten Chinese pregnant women with a history of abuse by their intimate partners. METHODS Women were randomised to the experimental or control group. Experimental group women received empowerment training specially designed for Chinese abused pregnant women while the control group women received standard care for abused women. Data were collected at study entry and six weeks postnatal. MAIN OUTCOMES MEASURES IPV [on the Conflict Tactics Scale (CTS)], health-related quality of life (SF-36) and postnatal depression [Edinburgh Postnatal Depression Scale (EPDS)]. RESULTS Following the training, the experimental group had significantly higher physical functioning and had significantly improved role limitation due to physical problems and emotional problems. They also reported less psychological (but not sexual) abuse, minor (but not severe) physical violence and had significantly lower postnatal depression scores. However, they reported more bodily pain. CONCLUSION An empowerment intervention specially designed for Chinese abused pregnant women was effective in reducing IPV and improving the health status of the women.
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20 |
139 |
7
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Mega MS, Chen SS, Thompson PM, Woods RP, Karaca TJ, Tiwari A, Vinters HV, Small GW, Toga AW. Mapping histology to metabolism: coregistration of stained whole-brain sections to premortem PET in Alzheimer's disease. Neuroimage 1997; 5:147-53. [PMID: 9345544 DOI: 10.1006/nimg.1996.0255] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The association between [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) counts obtained 8 h before death and neurofibrillary tangle (NFT) staining density in a patient with Alzheimer's disease (AD) was evaluated. In our patient FDG-PET counts were globally decreased with a greater focal deficit in the left medial temporal region independent of volume loss. After death, whole-brain sections derived from cryomacrotome sectioning were stained for NFTs by the Gallyas method and elastically warped into their native space enabling registration with premortem FDG-PET data. Gallyas staining density was localized to the paralimbic cortex of the basal forebrain, medial temporal, and orbital frontal regions. The poor correlation between NFT staining density and hypometabolism on FDG-PET implicates alternate mechanisms underlying the metabolic defect in AD.
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28 |
111 |
8
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Tiwari A, Chan KL, Fong D, Leung WC, Brownridge DA, Lam H, Wong B, Lam CM, Chau F, Chan A, Cheung KB, Ho PC. The impact of psychological abuse by an intimate partner on the mental health of pregnant women. BJOG 2008; 115:377-84. [PMID: 18190375 PMCID: PMC2253706 DOI: 10.1111/j.1471-0528.2007.01593.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Objective The objective of this first population-based study in Hong Kong was to assess the impact of psychological abuse by an intimate partner on the mental health of pregnant women. Design Survey. Setting Antenatal clinics in seven public hospitals in Hong Kong. Population Three thousand two hundred and forty-five pregnant women. Methods The Abuse Assessment Screen (AAS) and demographic questionnaires were administered face-to-face at 32–36 weeks of gestation. At 1 week postpartum, the AAS, Edinburgh Postnatal Depression Scale and SF-12 Health Survey were administered by telephone. Main outcome measures Intimate partner violence, postnatal depression and health-related quality of life. Results Two hundred and ninety six (9.1%) of the participants reported abuse by an intimate partner in the past year. Of those abused, 216 (73%) reported psychological abuse only and 80 (27%) reported physical and/or sexual abuse. Forty six (57.5%) in the physical and/or sexual abuse group also reported psychological abuse. Women in the psychological abuse only group had a higher risk of postnatal depression compared with nonabused women (adjusted OR: 1.84, 95% CI: 1.12–3.02). They were also at a higher risk of thinking about harming themselves (adjusted OR: 3.50, 95% CI: 1.49–8.20) and had significantly poorer mental health-related quality of life (P < 0.001). The higher risks of postnatal depression and thinking of harming themselves were not observed in the physical and/or sexual abuse group although significantly poorer mental health-related quality of life (P < 0.001) was observed. Conclusions Psychological abuse by an intimate partner against pregnant women has a negative impact on their mental health postdelivery. Furthermore, psychological abuse in the absence of physical and/or sexual abuse can have a detrimental effect on the mental health of abused women. The findings underscore the importance of screening pregnant women for abuse by an intimate partner and the need for developing, implementing and evaluating interventions to address psychological abuse. Please cite this paper as: Tiwari A, Chan K, Fong D, Leung W, Brownridge D, Lam H, Wong B, Lam C, Chau F, Chan A, Cheung K, Ho P. The impact of psychological abuse by an intimate partner on the mental health of pregnant women. BJOG 2008;115:377–384.
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Research Support, Non-U.S. Gov't |
17 |
108 |
9
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Tiwari A, Patnayak DP, Chander Y, Parsad M, Goyal SM. Survival of two avian respiratory viruses on porous and nonporous surfaces. Avian Dis 2006; 50:284-7. [PMID: 16863083 DOI: 10.1637/7453-101205r.1] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The transmission of pathogens from infected to susceptible hosts may occur through contaminated fomites and inanimate objects. This type of transmission depends on the ability of the pathogens to survive in the environment. In this report, we describe the survivability of two avian respiratory viruses, e.g., avian metapneumovirus and avian influenza virus on 12 different porous and nonporous surfaces. The viruses survived on some of the surfaces for up to 6 days postcontamination but not after 9 days. Both viruses survived longer on nonporous surfaces than on porous ones. One of the reasons for poor survival on porous surfaces could be inefficient elution of virus from these surfaces. These results should be helpful in determining how long the premises should be left vacant after an outbreak of these viruses has occurred in poultry houses.
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Research Support, Non-U.S. Gov't |
19 |
103 |
10
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Oduguwa V, Tiwari A, Roy R. Evolutionary computing in manufacturing industry: an overview of recent applications. Appl Soft Comput 2005. [DOI: 10.1016/j.asoc.2004.08.003] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20 |
101 |
11
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Tiwari A, Salacinski HJ, Hamilton G, Seifalian AM. Tissue engineering of vascular bypass grafts: role of endothelial cell extraction. Eur J Vasc Endovasc Surg 2001; 21:193-201. [PMID: 11352676 DOI: 10.1053/ejvs.2001.1316] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Surgical treatment of vascular disease has become common. The use of synthetic materials is limited to grafts larger than 5-6 mm, because of the frequency of occlusion observed with small-diameter prosthetics. An alternative would be a hybrid or tissue-engineered graft with the surface coated with a monolayer of the patients' own endothelial cells. This review examines the various techniques and technologies used to date in order to extract endothelial cells for such graft engineering.
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Review |
24 |
86 |
12
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Tiwari A, Singh V. Synthesis and characterization of electrical conducting chitosan-graft-polyaniline. EXPRESS POLYM LETT 2007. [DOI: 10.3144/expresspolymlett.2007.44] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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18 |
84 |
13
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Singh V, Tiwari A, Pandey S, Singh SK. Peroxydisulfate initiated synthesis of potato starch-graft-poly(acrylonitrile) under microwave irradiation. EXPRESS POLYM LETT 2007. [DOI: 10.3144/expresspolymlett.2007.10] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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18 |
80 |
14
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Tiwari A, Cheng KS, Salacinski H, Hamilton G, Seifalian AM. Improving the patency of vascular bypass grafts: the role of suture materials and surgical techniques on reducing anastomotic compliance mismatch. Eur J Vasc Endovasc Surg 2003; 25:287-95. [PMID: 12651165 DOI: 10.1053/ejvs.2002.1810] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND compliance mismatch is an important factor in the development of myointimal hyperplasia in both coronary and vascular anastomoses. This mismatch may be reduced by the use of newer suture materials and techniques. This review discusses the current techniques and materials used to date in generating anastomoses in both coronary and vascular applications and to correlate these with the degree of inherent compliance achieved. METHODS PubMed, ISIS, CAS and PAS database searches were performed. Other articles were cross-referenced. RESULTS AND CONCLUSION continuous suture is still the most used technique in both cardiac and vascular surgery for the generation of anastomoses due to the reduced time and improved haemostasis. However, continuous suture results in a greater compliance mismatch than the interrupted technique. Vein cuffs and patches improve compliance and transmission of pulsatile blood flow and offer improvement of graft patency. Alternative to sutures are biological glue, clips and laser generated solders all of which have shown promising results, but further work is required before they become applicable for routine use.
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Review |
22 |
74 |
15
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Salacinski HJ, Tiwari A, Hamilton G, Seifalian AM. Cellular engineering of vascular bypass grafts: role of chemical coatings for enhancing endothelial cell attachment. Med Biol Eng Comput 2001; 39:609-18. [PMID: 11804165 DOI: 10.1007/bf02345431] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Surgical treatment of vascular disease has become common. The use of synthetic materials is limited to grafts larger than 5-6mm, because of the frequency of occlusion observed with small-diameter prosthetics. An alternative would be a hybrid or tissue-engineered graft with the surface coated with a monolayer of the patient's own cells. Currently, to be effective, high-density seeding regimens have to be undertaken. This is because endothelial cells (ECs) are washed off the graft lumen once exposed to physiological blood flow. EC attachment has been shown to be significantly improved by pre-coating with substances known to attach ECs selectively. The review examines the various types of coating and bonding technology used to date to enhance endothelial cell attachment onto the surface of prosthetic vascular bypass grafts.
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Review |
24 |
68 |
16
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Maini L, Sharma A, Jha S, Sharma A, Tiwari A. Three-dimensional printing and patient-specific pre-contoured plate: future of acetabulum fracture fixation? Eur J Trauma Emerg Surg 2016; 44:215-224. [PMID: 27785534 DOI: 10.1007/s00068-016-0738-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 10/22/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE Due to the complexity of acetabulum, achieving anatomical contouring intra-operatively is difficult for surgeon. A 3D (dimensional) real model can facilitate us both in contouring the plate pre-operatively and in better pre-operative planning. Patient-specific pre-contoured plate in acetabular fracture has been studied by few researchers but randomized case-control study was lacking. Hence, we conducted a case-control study to evaluate the accuracy of patient-specific pre-contoured plate. MATERIALS AND METHODS Prospective randomized case control study was conducted. 21 patients were included. 10 patients were distributed in "case" group and remaining 11 in "control" group. INCLUSION CRITERIA Displaced acetabulum fractures with displacement of ≥3 mm in adults who reported within 3 weeks of injury. Exclusion criteria were: Open fractures, associated Morel-Lavallée lesion and patients with >3 weeks old fracture. In case group, patient-specific real 3D model of fractured acetabulum was generated using rapid prototyping technology and plates were contoured pre-operatively. Control group was treated using intra-operative contoured plates. Both the groups were compared using parameters: Blood loss, Surgery time, post-operative reduction on X-ray, post-surgical residual displacement and reduction achieved as evaluated by CT scan. RESULTS Reduced blood loss (100 ml less in case group) and surgical time (12 min less in case group) and better post-operative reduction were observed in case than control. In control group, 4 patients even had step of 2-3 mm, which was not seen in case group. All the pre-contoured plates fitted well to the pelvis intra-operatively. Reduction achieved as evaluated by CT was more in "case" group with statistically significant outcomes (p < 0.05). CONCLUSION Patient-specific pre-contoured plate made using 3D model is a better implant than intra-operatively contoured plate. Real-time 3D pelvis model is an accurate technique for pre-operative planning in acetabular fractures.
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Randomized Controlled Trial |
9 |
62 |
17
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Tiwari A, Fong DYT, Chan KL, Leung WC, Parker B, Ho PC. Identifying intimate partner violence: comparing the Chinese Abuse Assessment Screen with the Chinese Revised Conflict Tactics Scales. BJOG 2007; 114:1065-71. [PMID: 17617187 PMCID: PMC1974837 DOI: 10.1111/j.1471-0528.2007.01441.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2007] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To assess the measurement accuracy and the utility of the Chinese Abuse Assessment Screen (AAS). DESIGN A cross-sectional study. SETTING An antenatal clinic of a public hospital and a community centre in Hong Kong. SAMPLE A total of 257 Chinese women consisting of 100 pregnant women and 157 nonpregnant women. METHOD The Chinese AAS was administered first, followed by the Chinese Revised Conflict Tactics Scales (CTS2). This was performed in the same sitting, and each participant was interviewed once either at an antenatal clinic (for the pregnant women sample) or at a community centre (for the nonpregnant women sample). MAIN OUTCOME MEASURES Estimates of the sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios. RESULTS Using the Chinese CTS2 as the standard, the specificity estimates of the Chinese AAS for emotional, physical and sexual abuse were > or = 89%, while the sensitivity estimates varied from 36.3 to 65.8%. The sensitivity improved in the screening for more severe cases (66.7%). The positive predictive values were > or = 80%, and the negative predictive values varied from 66 to 93%. Factors such as the age difference between the couple and the woman's need for financial assistance were found to be associated with intimate partner violence (IPV). CONCLUSION The Chinese AAS has demonstrated satisfactory measurement accuracy and utility for identifying IPV when the Chinese CTS2 was used as the standard.
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Comparative Study |
18 |
62 |
18
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Singh M, Pawar M, Bothra A, Maheshwari A, Dubey V, Tiwari A, Kelati A. Personal protective equipment induced facial dermatoses in healthcare workers managing Coronavirus disease 2019. J Eur Acad Dermatol Venereol 2020; 34:e378-e380. [PMID: 32396675 PMCID: PMC7272982 DOI: 10.1111/jdv.16628] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Letter |
5 |
55 |
19
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Cheng KS, Tiwari A, Boutin A, Denton CP, Black CM, Morris R, Hamilton G, Seifalian AM. Carotid and femoral arterial wall mechanics in scleroderma. Rheumatology (Oxford) 2003; 42:1299-305. [PMID: 12777634 DOI: 10.1093/rheumatology/keg371] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE Large-vessel arterial disease is increasingly recognized as a major cause of morbidity in autoimmune rheumatic disorders. Recent evidence suggests that scleroderma (systemic sclerosis, SSc) may be linked to altered fibrillin-1 metabolism associated with a defect in chromosome 15q. If this is the case, we may expect to see changes in the arterial wall mechanics of large vessels not clinically involved in the disease process. We undertook a study to determine whether the biomechanical properties and intima-media thickness (IMT) of the elastic carotid artery and the muscular femoral artery are altered in subjects with limited (lcSSc) and diffuse (dcSSc) cutaneous SSc. METHODS Measurements of carotid and femoral wall mechanics were made in 33 patients with lcSSc, 19 patients with dcSSc and 21 control subjects, using a duplex scanner coupled to a Wall Track system. Their age, gender, body mass index, heart rate, systolic and diastolic blood pressures, presumed cardiovascular load, and plasma creatinine, fasting cholesterol, triglyceride and glucose concentrations were also measured. RESULTS There was a progressive and significant reduction (P < 0.001) in the elastic properties of the carotid artery from the control group (compliance, 16.24 +/- 4.39 %mmHg(-1) x 10(-2)) to the lcSSc group (10.89 +/- 2.43 %mmHg(-1) x 10(-2)) to the dcSSc group (7.65 +/- 2.08 %mmHg(-1) x 10(-2)), even after adjustment for the systemic physiological and biochemical variables studied, which are known to influence the mechanics of arterial walls. There was no apparent difference between the groups in the mean elastic indices of the femoral artery and the IMT of the carotid and femoral arteries. CONCLUSION The elastic properties of the carotid artery are significantly altered in SSc, and the two major subsets of SSc may be distinguished by their carotid artery biomechanics. This suggests that connective tissue abnormality occurs at sites not previously assessed.
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Clinical Trial |
22 |
54 |
20
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Hwang R, Zai C, Tiwari A, Müller DJ, Arranz MJ, Morris AG, McKenna PJ, Munro J, Potkin SG, Lieberman JA, Meltzer HY, Kennedy JL. Effect of dopamine D3 receptor gene polymorphisms and clozapine treatment response: exploratory analysis of nine polymorphisms and meta-analysis of the Ser9Gly variant. THE PHARMACOGENOMICS JOURNAL 2009; 10:200-18. [PMID: 20029384 DOI: 10.1038/tpj.2009.65] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
D2 blockade has been implicated in having a central role in antipsychotic response. However, treatment refractoriness, in spite of complete D2 blockade, as well as the efficacy of clozapine (CLZ) in a portion of this patient population, indicates the involvement of other factors as well. Several lines of evidence suggest a role for D3. Furthermore, an earlier meta-analysis by Jönsson et al. (2003) (n=233) suggested a role for genetic variation in the D3 gene. Relevant to this study, Jönsson et al. found the Ser allele of the D3 serine-to-glycine substitution at amino acid position 9 (Ser9Gly) polymorphism to be associated with worse CLZ response compared with the Gly allele. In this study, we attempt to validate these findings by performing a meta-analysis in a much larger sample (n=758). Eight other variants were also tested in our own sample to explore the possible effect of other regions of the gene. We report a negative but consistent trend across individual studies in our meta-analysis for the DRD3 Ser allele and poor CLZ response. A possible minor role for this single-nucleotide polymorphism cannot be disregarded, as our sample size may have been insufficient. Other DRD3 variants and haplotypes of possible interest were also identified for replication in future studies.
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Research Support, Non-U.S. Gov't |
16 |
52 |
21
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Howard DH, Rafie R, Tiwari A, Faull KF. Hydroxamate siderophores of Histoplasma capsulatum. Infect Immun 2000; 68:2338-43. [PMID: 10722639 PMCID: PMC97423 DOI: 10.1128/iai.68.4.2338-2343.2000] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/1999] [Accepted: 01/03/2000] [Indexed: 11/20/2022] Open
Abstract
The zoopathogenic fungus Histoplasma capsulatum, like other eukaryotic aerobic microorganisms, requires iron for growth. Under conditions of low iron availability, the fungus secretes hydroxamates that function as siderophores (iron chelators). The experiments to be reported were designed to gather further information on the hydroxamate siderophores of H. capsulatum. The fungus was grown in a synthetic medium deferrated with the cationic exchange resin Chelex 100. Siderophores were detected after 4 days of incubation at 37 degrees C in media containing 0.3 to 1.0 microM iron. The secretion was suppressed by 10 microM iron. The hydroxamates were purified by reverse-phase and size-exclusion chromatography. On the basis of ions observed during electrospray mass spectroscopy, five hydroxamate siderophores were tentatively identified: dimerum acid, acetyl dimerum acid, coprogen B, methyl coprogen B, and fusarinine (monomeric). A polyclonal antibody to dimerum acid was generated. This reagent cross-reacted with coprogen B and fusarinine. Thus, the antibody detects hydroxamates in all three families of siderophores excreted by H. capsulatum.
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research-article |
25 |
49 |
22
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Al-Mufti F, Amuluru K, Sahni R, Bekelis K, Karimi R, Ogulnick J, Cooper J, Overby P, Nuoman R, Tiwari A, Berekashvili K, Dangayach N, Liang J, Gupta G, Khandelwal P, Dominguez JF, Sursal T, Kamal H, Dakay K, Taylor B, Gulko E, El-Ghanem M, Mayer SA, Gandhi C. Cerebral Venous Thrombosis in COVID-19: A New York Metropolitan Cohort Study. AJNR Am J Neuroradiol 2021; 42:1196-1200. [PMID: 33888450 DOI: 10.3174/ajnr.a7134] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 02/23/2021] [Indexed: 12/28/2022]
Abstract
BACKGROUND AND PURPOSE Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection is associated with hypercoagulability. We sought to evaluate the demographic and clinical characteristics of cerebral venous thrombosis among patients hospitalized for coronavirus disease 2019 (COVID-19) at 6 tertiary care centers in the New York City metropolitan area. MATERIALS AND METHODS We conducted a retrospective multicenter cohort study of 13,500 consecutive patients with COVID-19 who were hospitalized between March 1 and May 30, 2020. RESULTS Of 13,500 patients with COVID-19, twelve had imaging-proved cerebral venous thrombosis with an incidence of 8.8 per 10,000 during 3 months, which is considerably higher than the reported incidence of cerebral venous thrombosis in the general population of 5 per million annually. There was a male preponderance (8 men, 4 women) and an average age of 49 years (95% CI, 36-62 years; range, 17-95 years). Only 1 patient (8%) had a history of thromboembolic disease. Neurologic symptoms secondary to cerebral venous thrombosis occurred within 24 hours of the onset of the respiratory and constitutional symptoms in 58% of cases, and 75% had venous infarction, hemorrhage, or both on brain imaging. Management consisted of anticoagulation, endovascular thrombectomy, and surgical hematoma evacuation. The mortality rate was 25%. CONCLUSIONS Early evidence suggests a higher-than-expected frequency of cerebral venous thrombosis among patients hospitalized for COVID-19. Cerebral venous thrombosis should be included in the differential diagnosis of neurologic syndromes associated with SARS-CoV-2 infection.
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Multicenter Study |
4 |
49 |
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Tiwari A, Vanleeuwen JA, Dohoo IR, Keefe GP, Haddad JP, Tremblay R, Scott HM, Whiting T. Production effects of pathogens causing bovine leukosis, bovine viral diarrhea, paratuberculosis, and neosporosis. J Dairy Sci 2007; 90:659-69. [PMID: 17235141 DOI: 10.3168/jds.s0022-0302(07)71548-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The primary purpose of this research was to determine associations among seropositivity for bovine leukemia virus (BLV), bovine viral diarrhea virus (BVDV), Mycobacterium avium ssp. paratuberculosis (MAP), and Neospora caninum (NC) and each of 3 outcome variables (305-d milk, fat, and protein production) in Canadian dairy cattle. Serum samples from up to 30 randomly selected cows from 342 herds on monthly milk testing were tested for antibodies against BLV (IDEXX ELISA; IDEXX Corporation, Westbrook, ME), MAP (IDEXX or Biocor ELISA; Biocor Animal Health, Inc., Omaha, NE), and NC (IDEXX or Biovet ELISA; Biovet Inc., St. Hyacinthe, Quebec, Canada). Up to 5 unvaccinated cattle over 6 mo of age were tested for virus-neutralizing antibodies to the Singer strain of type 1 BVDV. Dairy Herd Improvement records were obtained electronically for all sampled cows. Linear mixed models with herd and cow as random variables were fit, with significant restricted maximum likelihood estimates of outcome effects being obtained, while controlling for potential confounding variables. Bovine leukemia virus seropositivity was not associated with 305-d milk, 305-d fat, or 305-d protein production. Cows in BVDV-seropositive herds (at least one unvaccinated animal with a titer > or =1:64) had reductions in 305-d milk, fat, and protein of 368, 10.2, and 9.5 kg, respectively, compared with cows in BVDV-seronegative herds. Mycobacterium avium ssp. paratuberculosis seropositivity was associated with lower 305-d milk of 212 kg in 4+-lactation cows compared with MAP-seronegative 4+-lactation cows. Neospora caninum seropositivity in primiparous cows was associated with lower 305-d milk, fat, and protein of 158, 5.5, and 3.3 kg, respectively, compared with NC-seronegative primiparous cows. There were no interactions among seropositivity for any of the pathogens and their effects on any of the outcomes examined, although the low MAP seroprevalence limited this analysis. Results from this research will contribute to understanding the economic impacts of these pathogens and justify their control.
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Research Support, Non-U.S. Gov't |
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Almassalha LM, Tiwari A, Ruhoff PT, Stypula-Cyrus Y, Cherkezyan L, Matsuda H, Dela Cruz MA, Chandler JE, White C, Maneval C, Subramanian H, Szleifer I, Roy HK, Backman V. The Global Relationship between Chromatin Physical Topology, Fractal Structure, and Gene Expression. Sci Rep 2017; 7:41061. [PMID: 28117353 PMCID: PMC5259786 DOI: 10.1038/srep41061] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 12/12/2016] [Indexed: 02/07/2023] Open
Abstract
Most of what we know about gene transcription comes from the view of cells as molecular machines: focusing on the role of molecular modifications to the proteins carrying out transcriptional reactions at a loci-by-loci basis. This view ignores a critical reality: biological reactions do not happen in an empty space, but in a highly complex, interrelated, and dense nanoenvironment that profoundly influences chemical interactions. We explored the relationship between the physical nanoenvironment of chromatin and gene transcription in vitro. We analytically show that changes in the fractal dimension, D, of chromatin correspond to simultaneous increases in chromatin accessibility and compaction heterogeneity. Using these predictions, we demonstrate experimentally that nanoscopic changes to chromatin D within thirty minutes correlate with concomitant enhancement and suppression of transcription. Further, we show that the increased heterogeneity of physical structure of chromatin due to increase in fractal dimension correlates with increased heterogeneity of gene networks. These findings indicate that the higher order folding of chromatin topology may act as a molecular-pathway independent code regulating global patterns of gene expression. Since physical organization of chromatin is frequently altered in oncogenesis, this work provides evidence pairing molecular function to physical structure for processes frequently altered during tumorigenesis.
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Research Support, U.S. Gov't, Non-P.H.S. |
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Tiwari A, Shukla SK. Chitosan-g-polyaniline: a creatine amidinohydrolase immobilization matrix for creatine biosensor. EXPRESS POLYM LETT 2009. [DOI: 10.3144/expresspolymlett.2009.69] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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