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Murray RT, Runcorn TH, Guha S, Taylor JR. High average power parametric wavelength conversion at 3.31-3.48 m in MgO:PPLN. OPTICS EXPRESS 2017; 25:6421-6430. [PMID: 28380992 DOI: 10.1364/oe.25.006421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present results of high average power mid-infrared (mid-IR) generation employing synchronized nanosecond pulsed ytterbium and erbium fiber amplifier systems using periodically poled lithium niobate. We generate greater than 6 W of mid-IR radiation tunable in wavelength between 3.31-3.48 μm, at power conversion efficiencies exceeding 75%, with near diffraction limited beam quality (M2 = 1.4). Numerical modeling is used to verify the experimental results in differing pump depletion regimes.
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Ayim F, Tapp S, Guha S, Ameye L, Al-Memar M, Sayasneh A, Bottomley C, Gould D, Stalder C, Timmerman D, Bourne T. Can risk factors, clinical history and symptoms be used to predict risk of ectopic pregnancy in women attending an early pregnancy assessment unit? ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2016; 48:656-662. [PMID: 27854390 DOI: 10.1002/uog.16007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 06/14/2016] [Accepted: 06/21/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVE To examine whether risk factors and symptoms may be used to predict the likelihood of ectopic pregnancy (EP) in women attending early pregnancy assessment units in the UK. METHODS This was an observational cohort study of pregnant women under 12 weeks' gestation who were recruited from three London university hospitals between August 2012 and April 2013. One hospital continued recruitment between January and June 2015. A standardized information sheet incorporating patient demographics, medical history and symptoms was completed by patients and confirmed by examining clinicians. The outcome measure was final pregnancy location. RESULTS There were 1320 eligible patients included in the analysis, with a total of 72 EPs (rate of 6%). Pelvic pain and diarrhea > three times in the previous 24 h were independent symptoms that increased the risk of EP, with relative risks of 2.4 (95% CI, 1.4-4.0; P = 0.002) and 2.2 (95% CI, 1.08-4.5; P = 0.03), respectively. The only other independent marker of risk of EP was duration of vaginal bleeding; the risk of EP increased by 20% (95% CI, 14%-27%) for every 1-day increment in duration (P < 0.001). A logistic regression model incorporating these factors demonstrated an area under the receiver-operating characteristics curve of 0.73 (95% CI, 0.67-0.79). The prevalence of EP was low when there was no pelvic pain, no diarrhea and the duration of bleeding was ≤ 3 days, with an EP rate of 2% (6/391). In the presence of a single risk factor, the EP rate increased to 5% (29/631) when only pelvic pain was present, 8% (1/12) when only diarrhea > three times in the previous 24 h was reported and 9% (9/103) when there was only vaginal bleeding with a duration > 3 days. Women with pelvic pain and vaginal bleeding of any severity for > 3 days had a high EP rate of 16% (23/146). In the nine women who also reported diarrhea > three times in the previous 24 h, two had EP. CONCLUSIONS Only the presence of pelvic pain, diarrhea > three times in the previous 24 h and duration of bleeding were symptoms that significantly increased the risk for EP in women attending early pregnancy assessment units. Risk factors and symptoms alone could not be used to predict reliably an EP. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
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Van Calster B, Bobdiwala S, Guha S, Van Hoorde K, Al-Memar M, Harvey R, Farren J, Kirk E, Condous G, Sur S, Stalder C, Timmerman D, Bourne T. Managing pregnancy of unknown location based on initial serum progesterone and serial serum hCG levels: development and validation of a two-step triage protocol. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2016; 48:642-649. [PMID: 26776599 DOI: 10.1002/uog.15864] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 01/08/2016] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
OBJECTIVES A uniform rationalized management protocol for pregnancies of unknown location (PUL) is lacking. We developed a two-step triage protocol to select PUL at high risk of ectopic pregnancy (EP), based on serum progesterone level at presentation (step 1) and the serum human chorionic gonadotropin (hCG) ratio, defined as the ratio of hCG at 48 h to hCG at presentation (step 2). METHODS This was a cohort study of 2753 PUL (301 EP), involving a secondary analysis of prospectively and consecutively collected PUL data from two London-based university teaching hospitals. Using a chronological split we used 1449 PUL for development and 1304 for validation. We aimed to assign PUL as low risk with high confidence (high negative predictive value (NPV)) while classifying most EP as high risk (high sensitivity). The first triage step assigned PUL as low risk using a threshold of serum progesterone at presentation. The remaining PUL were triaged using a novel logistic regression risk model based on hCG ratio and initial serum progesterone (second step), defining low risk as an estimated EP risk of < 5%. RESULTS On validation, initial serum progesterone ≤ 2 nmol/L (step 1) classified 16.1% PUL as low risk. Second-step classification with the risk model selected an additional 46.0% of all PUL as low risk. Overall, the two-step protocol classified 62.1% of PUL as low risk, with an NPV of 98.6% and a sensitivity of 92.0%. When the risk model was used in isolation (i.e. without the first step), 60.5% of PUL were classified as low risk with 99.1% NPV and 94.9% sensitivity. CONCLUSION PUL can be classified efficiently into being either high or low risk for complications using a two-step protocol involving initial progesterone and hCG levels and the hCG ratio. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
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Bobdiwala S, Guha S, Van Calster B, Ayim F, Mitchell-Jones N, Al-Memar M, Mitchell H, Stalder C, Bottomley C, Kothari A, Timmerman D, Bourne T. The clinical performance of the M4 decision support model to triage women with a pregnancy of unknown location as at low or high risk of complications. Hum Reprod 2016; 31:1425-35. [PMID: 27165655 DOI: 10.1093/humrep/dew105] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 04/07/2016] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION What are the adverse outcomes associated with using the M4 model in everyday clinical practice for women with pregnancy of unknown location (PUL)? SUMMARY ANSWER There were 17/835 (2.0%) adverse events and no serious adverse events associated with the performance of the M4 model in clinical practice. WHAT IS KNOWN ALREADY The M4 model has previously been shown to stratify women classified as a PUL as at low or high risk of complications with a good level of test performance. The triage performance of the M4 model is better than single measurements of serum progesterone or the hCG ratio (serum hCG at 48 h/hCG at presentation). STUDY DESIGN, SIZE, DURATION A prospective multi-centre cohort study of 1022 women with a PUL carried out between August 2012 and December 2013 across 2 university teaching hospitals and 1 district general hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS All women presenting with a PUL to the early pregnancy units of the three hospitals were recruited. The final outcome for PUL was either a failed PUL (FPUL), intrauterine pregnancy (IUP) or ectopic pregnancy (EP) (including persistent PUL (PPUL)), with EP and PPUL considered high-risk PUL. Their hCG results at 0 and 48 h were entered into the M4 model algorithm. If the risk of EP was ≥5%, the PUL was predicted to be high-risk and the participant was asked to re-attend 48 h later for a repeat hCG and transvaginal ultrasound scan by a senior clinician. If the PUL was classified as 'low risk, likely failed PUL', the participant was asked to perform a urinary pregnancy test 2 weeks later. If the PUL was classified as 'low risk, likely intrauterine', the participant was scheduled for a repeat scan in 1 week. Deviations from the management protocol were recorded as either an 'unscheduled visit (participant reason)', 'unscheduled visit (clinician reason)' or 'differences in timing (blood test/ultrasound)'. Adverse events were assessed using definitions outlined in the UK Good Clinical Practice Guidelines' document. MAIN RESULTS AND THE ROLE OF CHANCE A total of 835 (82%) women classified as a PUL were managed according to the M4 model (9 met the exclusion criteria, 69 were lost to follow-up, 109 had no hCG result at 48 h). Of these, 443 (53%) had a final outcome of FPUL, 298 (36%) an IUP and 94 (11%) an EP. The M4 model predicted 70% (585/835) PUL as low risk, of which 568 (97%) were confirmed as FPUL or IUP. Of the 17 EP and PPUL misclassified as low risk, 5 had expectant management, 7 medical management with methotrexate and 5 surgical intervention.Nineteen PUL had an unscheduled visit (participant reason), 38 PUL had an unscheduled visit (clinician reason) and 68 PUL had deviations from protocol due to a difference in timing (blood test/ultrasound).Adverse events were reported in 26 PUL and 1 participant had a serious adverse event. A total of 17/26 (65%) adverse events were misclassifications of a high risk PUL as low risk by the M4 model, while 5/26 (19%) adverse events were related to incorrect clinical decisions. Four of the 26 adverse events (15%) were secondary to unscheduled admissions for pain/bleeding. The serious adverse event was due to an incorrect clinical decision. LIMITATIONS, REASONS FOR CAUTION A limitation of the study was that 69/1022 (7%) of PUL were lost to follow-up. A 48 h hCG level was missing for 109/1022 (11%) participants. WIDER IMPLICATIONS OF THE FINDINGS The low number of adverse events (2.0%) suggests that expectant management of PUL using the M4 prediction model is safe. The model is an effective way of triaging women with a PUL as being at high- and low-risk of complications and rationalizing follow-up. The multi-centre design of the study is more likely to make the performance of the M4 model generalizable in other populations. STUDY FUNDING/COMPETING INTERESTS None. TRIAL REGISTRATION NUMBER Not applicable.
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Ray S, Talukdar A, Sonthalia N, Saha M, Kundu S, Khanra D, Guha S, Basu AK, Mukherjee A, Ray D, Ganguly S. Serum lipoprotein ratios as markers of insulin resistance: a study among non-diabetic acute coronary syndrome patients with impaired fasting glucose. Indian J Med Res 2016; 141:62-7. [PMID: 25857496 PMCID: PMC4405942 DOI: 10.4103/0971-5916.154504] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND & OBJECTIVES Recent data suggest that insulin resistance can predict cardiovascular disease independently of the other risk factors, such as hypertension, visceral obesity or dyslipidaemia. However, the majority of available methods to evaluate insulin resistance are complicated to operate, expensive, and time consuming. This study was undertaken to assess whether serum lipoprotein ratios could predict insulin resistance in non-diabetic acute coronary syndrome (ACS) patients. METHODS Ninety non-diabetic patients with impaired fasting glucose admitted with a diagnosis of ACS were included in the study. At the time of admission fasting glucose and insulin concentrations were measured. The homeostatic model assessment-insulin resistance (HOMA-IR) was used for insulin resistance. The fasting serum total cholesterol (TC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-C) levels were checked, and then TC/HDL-C and TG/HDL-C ratios were calculated. The areas under the curves (AUC) of the receiver operating characteristic (ROC) curves were used to compare the power of these serum lipoprotein ratios as markers. RESULTS Lipoprotein ratios were significantly higher in patients with HOMA-IR index > 2.5 as compared to patients with index <2.5 (P < 0.05). Both TG/HDL-C and TC/HDL-C ratios were significantly correlated with HOMA-IR (P<0.05). The area under the ROC curve of the TG/HDL-C and TC/HDL-C ratio for predicting insulin resistance was 0.80 (95% CI, 0.67 to 0.93), 0.78 (95% CI, 0.65 to 0.91), respectively. INTERPRETATION & CONCLUSIONS The findings of this study demonstrate that serum lipoprotein ratios can provide a simple means of identifying insulin resistance and can be used as markers of insulin resistance and cardiovascular diseases risk in adult non-diabetic patients.
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Malik H, Sharma V, Saini S, Guha S, Malakar D. 225 AUTOLOGOUS TRANSPLANTATION OF MESENCHYMAL STEM CELLS DERIVED FROM ADIPOSE TISSUE IN ANIMAL. Reprod Fertil Dev 2016. [DOI: 10.1071/rdv28n2ab225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The present study was carried out for isolation and culture of adipose tissue-derived mesenchymal stem cells of goat (gADSC) and dogs (1 dog was suffering from hip dysplasia and another dog from paraplegia) and their characterisation with different markers. Adipose tissue of goat and dog were aseptically isolated and treated with collagenase for 2 h in a CO2 incubator. The enzymatic digested cells were filtered through a 41-µm filter and cells were resuspended in cell culture flask containing medium DMEM/F12, 10% fetal bovine serum, and 50 μg mL–1 gentamycin. In vitro-cultured ADSC were characterised by amplification of mesenchymal stem cell (MSC)-specific surface marker genes of CD44, CD29, and CD166 in PCR and by immunocytochemistry of MSC-specific marker of CD44. For in vitro chondrogenesis, ADSC at passage 3 were incubated in DMEM/F12 containing 100 nM dexamethasone, 1.25 μg mL–1 BSA, and 10 ng mL–1 BMP-4 ITS (insulin-transferrin-selenium) for 3 wk. Chondrogenic differentiation cells were confirmed by Safranin O staining and positive expression of chondrocyte-specific marker genes Aggrecan: primers F-TTGGACTTTGGCAGAATACC and R-CTTCCACCAATGTCGTATCC, and Collagen II: primers F-AACCCTGGAACTGACGGAAT and R-CTCACCCGTTTGACCTTTCG in PCR. Dog ADSC-derived chondrocytes were aseptically injected at 1 × 106 cells kg–1 of BW into dogs with hip dysplasia and paraplegia. Both dogs recovered well after 1 month of autologous transplantation and were able to move freely. Then, 10 dogs having massive wounds were injected with heterologous undifferentiated mesenchymal stem cells at 1 × 106 cells kg–1 of BW and all dogs were cured in an average of 20 days. Then, the paralyzed and fractured dogs were further treated with undifferentiated MSC at 1 × 106 cells kg–1 of BW and most of the dogs were cured properly. These findings may have implications for defining the physiological roles of ADSC in arthritis, some orthopaedic problems, joint regeneration, and neurological disorders and several new applications leading to novel therapeutic opportunities.
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Kogikoski S, Sousa CP, Liberato MS, Andrade-Filho T, Prieto T, Ferreira FF, Rocha AR, Guha S, Alves WA. Multifunctional biosensors based on peptide–polyelectrolyte conjugates. Phys Chem Chem Phys 2016; 18:3223-33. [DOI: 10.1039/c5cp07165h] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The crystal structure of self-assembled peptide nanostructures dictates the conductivity. We show that the orthorhombic phase can be doped with PAH, improving hole and electron injection, opening opportunities for self-assembled peptide composites.
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Liberato MS, Kogikoski S, da Silva ER, de Araujo DR, Guha S, Alves WA. Polycaprolactone fibers with self-assembled peptide micro/nanotubes: a practical route towards enhanced mechanical strength and drug delivery applications. J Mater Chem B 2016; 4:1405-1413. [DOI: 10.1039/c5tb02240a] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The conjugation between micro/nanotubes of l,l-diphenylalanine and polycaprolactone has led to ductile composite fibers suitable for designing polymer membranes potentially usable as degradable skin patches in drug delivery.
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Ray M, Guha S, Ray M, Kundu A, Ray B, Kundu K, Goswami S, Bhatt D, Selker H, Goldberg R. Cardiovascular health awareness among school-aged children in a rural district of India. Indian Heart J 2015. [DOI: 10.1016/j.ihj.2015.10.274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Buchmueller O, Citron M, Ellis J, Guha S, Marrouche J, Olive KA, de Vries K, Zheng J. Collider Interplay for Supersymmetry, Higgs and Dark Matter. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2015; 75:469. [PMID: 26457063 PMCID: PMC4591918 DOI: 10.1140/epjc/s10052-015-3675-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
We discuss the potential impacts on the CMSSM of future LHC runs and possible [Formula: see text] and higher-energy proton-proton colliders, considering searches for supersymmetry via [Formula: see text] events, precision electroweak physics, Higgs measurements and dark matter searches. We validate and present estimates of the physics reach for exclusion or discovery of supersymmetry via [Formula: see text] searches at the LHC, which should cover the low-mass regions of the CMSSM parameter space favoured in a recent global analysis. As we illustrate with a low-mass benchmark point, a discovery would make possible accurate LHC measurements of sparticle masses using the MT2 variable, which could be combined with cross-section and other measurements to constrain the gluino, squark and stop masses and hence the soft supersymmetry-breaking parameters [Formula: see text] and [Formula: see text] of the CMSSM. Slepton measurements at CLIC would enable [Formula: see text] and [Formula: see text] to be determined with high precision. If supersymmetry is indeed discovered in the low-mass region, precision electroweak and Higgs measurements with a future circular [Formula: see text] collider (FCC-ee, also known as TLEP) combined with LHC measurements would provide tests of the CMSSM at the loop level. If supersymmetry is not discovered at the LHC, it is likely to lie somewhere along a focus-point, stop-coannihilation strip or direct-channel A / H resonance funnel. We discuss the prospects for discovering supersymmetry along these strips at a future circular proton-proton collider such as FCC-hh. Illustrative benchmark points on these strips indicate that also in this case FCC-ee could provide tests of the CMSSM at the loop level.
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Guha S, Warsinke A, Tientcheu CM, Schmalz K, Meliani C, Wenger C. Label free sensing of creatinine using a 6 GHz CMOS near-field dielectric immunosensor. Analyst 2015; 140:3019-27. [PMID: 25782697 DOI: 10.1039/c4an02194k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work we present a CMOS high frequency direct immunosensor operating at 6 GHz (C-band) for label free determination of creatinine. The sensor is fabricated in standard 0.13 μm SiGe:C BiCMOS process. The report also demonstrates the ability to immobilize creatinine molecules on a Si3N4 passivation layer of the standard BiCMOS/CMOS process, therefore, evading any further need of cumbersome post processing of the fabricated sensor chip. The sensor is based on capacitive detection of the amount of non-creatinine bound antibodies binding to an immobilized creatinine layer on the passivated sensor. The chip bound antibody amount in turn corresponds indirectly to the creatinine concentration used in the incubation phase. The determination of creatinine in the concentration range of 0.88-880 μM is successfully demonstrated in this work. A sensitivity of 35 MHz/10 fold increase in creatinine concentration (during incubation) at the centre frequency of 6 GHz is gained by the immunosensor. The results are compared with a standard optical measurement technique and the dynamic range and sensitivity is of the order of the established optical indication technique. The C-band immunosensor chip comprising an area of 0.3 mm(2) reduces the sensing area considerably, therefore, requiring a sample volume as low as 2 μl. The small analyte sample volume and label free approach also reduce the experimental costs in addition to the low fabrication costs offered by the batch fabrication technique of CMOS/BiCMOS process.
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Guha S, Schmalz K, Wenger C, Herzel F. Self-calibrating highly sensitive dynamic capacitance sensor: towards rapid sensing and counting of particles in laminar flow systems. Analyst 2015; 140:3262-72. [PMID: 25793229 DOI: 10.1039/c5an00187k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this report we propose a sensor architecture and a corresponding read-out technique on silicon for the detection of dynamic capacitance change. This approach can be applied to rapid particle counting and single particle sensing in a fluidic system. The sensing principle is based on capacitance variation of an interdigitated electrode (IDE) structure embedded in an oscillator circuit. The capacitance scaling of the IDE results in frequency modulation of the oscillator. A demodulator architecture is employed to provide a read-out of the frequency modulation caused by the capacitance change. A self-calibrating technique is employed at the read-out amplifier stage. The capacitance variation of the IDE due to particle flow causing frequency modulation and the corresponding demodulator read-out has been analytically modelled. Experimental verification of the established model and the functionality of the sensor chip were shown using a modulating capacitor independent of fluidic integration. The initial results show that the sensor is capable of detecting frequency changes of the order of 100 parts per million (PPM), which translates to a shift of 1.43 MHz at 14.3 GHz operating frequency. It is also shown that a capacitance change every 3 μs can be accurately detected.
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Mann K, Massey TL, Guha S, van Kleef JP, Maharbiz MM. A wearable wireless platform for visually stimulating small flying insects. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:1654-7. [PMID: 25570291 DOI: 10.1109/embc.2014.6943923] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Linking neurons and muscles to their roles in behavior requires not only the ability to measure their response during unrestrained movement but also the ability to stimulate them and observe the behavioral results. Current wireless stimulation technologies can be carried by rodent-sized animals and very large insects. However, the mass and volume of these devices make them impractical for studying smaller animals like insects. Here we present a battery-powered electronics platform suitable to be carried on a flying locust (2.7 g). The device has an IR-based (infrared) receiver, can deliver optical or electrical stimulation, occupies a volume of 0.1 cm(3), and weighs ~280 mg. We show the device is capable of powering two white SMD light emitting diodes (LEDs) for ~4 min and can be recharged in ~20 min. We demonstrate that our system shows no crosstalk with an IR-based Vicon tracking system. The entire package is made from commercial off-the-shelf components and requires no microfabrication.
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Shah K, Roy R, Guha S, Bhargava M, Shah SV, Lobo A, Das D, Majumder AK. Severe visual loss following obstetric forceps delivery-related ocular trauma in a neonate. J OBSTET GYNAECOL 2014; 35:415. [PMID: 25356829 DOI: 10.3109/01443615.2014.969205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Banerjee R, Ray K, Bhattacherjee S, Guha S, Banerjee I, Nath I. A study of insulin resistance and its clinico-metabolic associations among apparently healthy individuals attending a tertiary care hospital. Ann Med Health Sci Res 2014; 4:823-8. [PMID: 25328801 PMCID: PMC4199182 DOI: 10.4103/2141-9248.141572] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Insulin resistance (IR), as a result of unhealthy life-styles and westernization, most likely contributes to the increased incidence of metabolic abnormalities and consequently, the development of metabolic syndrome (MS). AIM The present study was undertaken to determine the magnitude of IR and associated clinico-metabolic risk factors among the out-patients of a tertiary care hospital in Bihar, India. SUBJECTS AND METHODS Anthropometric profile, lipid profile, fasting blood glucose, C-reactive protein (CRP) and C-peptide of 112 individuals were measured using the standard procedures. IR was assessed using the homeostasis model (Homeostatic model assessment [HOMA]-IR). RESULTS The mean IR was 1.5 (1.0). Individuals with MS, higher body mass index and CRP ≥6 mg/l had higher IR. Linear regression showed, among the components of MS, waist circumference had the highest contribution toward IR. The optimal cut-off value to detect IR by HOMA2-IR was 1.35. CONCLUSION IR was found to have a strong association with various clinico-metabolic risk factors.
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Hashmi MA, Guha S, Sengupta P, Basu D, Baboo S, Neha. Thoracic cord compression by extramedullary hematopoiesis in thalassemia. Asian J Neurosurg 2014; 9:102-4. [PMID: 25126128 PMCID: PMC4129573 DOI: 10.4103/1793-5482.136726] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Extramedullary hematopoiesis (EMH) refers to hematopoiesis occurring outside the medulla of bone. It may be physiologic or due to pathological conditions like hematopoietic disorders. EMH can involve liver, spleen, thorax, and lymph nodes. It can involve paraspinal tissues with extension and involvement of spinal canal. In our case, the diagnosis was confirmed by the history of the patient stating underlying hematological condition and by magnetic resonance imaging (MRI) findings showing large soft tissue masses in paraspinal areas with involvement of spinal canal and leading to cord compression.
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You R, Li M, Guha S, Mulholland GW, Zachariah MR. Bionanoparticles as Candidate Reference Materials for Mobility Analysis of Nanoparticles. Anal Chem 2014; 86:6836-42. [DOI: 10.1021/ac403503q] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Sasaki T, Lian S, Qi J, Bayliss PE, Carr CE, Johnson JL, Guha S, Kobler P, Catz SD, Gill M, Jia K, Klionsky DJ, Kishi S. Aberrant autolysosomal regulation is linked to the induction of embryonic senescence: differential roles of Beclin 1 and p53 in vertebrate Spns1 deficiency. PLoS Genet 2014; 10:e1004409. [PMID: 24967584 PMCID: PMC4072523 DOI: 10.1371/journal.pgen.1004409] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 04/16/2014] [Indexed: 12/04/2022] Open
Abstract
Spinster (Spin) in Drosophila or Spinster homolog 1 (Spns1) in vertebrates is a putative lysosomal H+-carbohydrate transporter, which functions at a late stage of autophagy. The Spin/Spns1 defect induces aberrant autolysosome formation that leads to embryonic senescence and accelerated aging symptoms, but little is known about the mechanisms leading to the pathogenesis in vivo. Beclin 1 and p53 are two pivotal tumor suppressors that are critically involved in the autophagic process and its regulation. Using zebrafish as a genetic model, we show that Beclin 1 suppression ameliorates Spns1 loss-mediated senescence as well as autophagic impairment, whereas unexpectedly p53 deficit exacerbates both of these characteristics. We demonstrate that ‘basal p53’ activity plays a certain protective role(s) against the Spns1 defect-induced senescence via suppressing autophagy, lysosomal biogenesis, and subsequent autolysosomal formation and maturation, and that p53 loss can counteract the effect of Beclin 1 suppression to rescue the Spns1 defect. By contrast, in response to DNA damage, ‘activated p53’ showed an apparent enhancement of the Spns1-deficient phenotype, by inducing both autophagy and apoptosis. Moreover, we found that a chemical and genetic blockage of lysosomal acidification and biogenesis mediated by the vacuolar-type H+-ATPase, as well as of subsequent autophagosome-lysosome fusion, prevents the appearance of the hallmarks caused by the Spns1 deficiency, irrespective of the basal p53 state. Thus, these results provide evidence that Spns1 operates during autophagy and senescence differentially with Beclin 1 and p53. Spinster homolog 1 (Spns1) in vertebrates, as well as Spinster (Spin) in Drosophila, is a hypothetical lysosomal H+-carbohydrate transporter, which functions at a late stage of autophagy. The Spin/Spns1 defect induces aberrant autolysosome formation that leads to embryonic senescence and accelerated aging symptoms, while the molecular mechanisms of the pathogenesis are unknown in vivo. Using zebrafish, we show that Beclin 1 suppression ameliorates Spns1 loss-mediated senescence as well as autolysosomal impairment, whereas p53 deficit unexpectedly exacerbates these characteristics. We demonstrate that basal p53 activity has a certain protective role(s) against the Spns1 defect via suppressing autophagosome-lysosome fusion, while p53 activated by ultraviolet radiation amplifies the Spns1 deficit. In addition, we found that excessive lysosomal biogenesis and prolonged suboptimal acidification, modulated by v-ATPase, could be the primary reason for the appearance on the hallmarks of Spns1 deficiency. Our findings thus suggest that Spns1 is critically involved in lysosomal acidification and trafficking during autophagy, and differentially acts in a pathway with Beclin 1 and p53 in the regulation of senescence.
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Shukla S, Mahl TC, Guha S. Letter: probiotics vs. lactulose for minimal hepatic encephalopathy therapy--authors' reply. Aliment Pharmacol Ther 2014; 39:1001. [PMID: 24689352 DOI: 10.1111/apt.12700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 02/22/2014] [Indexed: 12/08/2022]
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Ikuta T, Peters BD, Guha S, John M, Karlsgodt KH, Lencz T, Szeszko PR, Malhotra AK. A schizophrenia risk gene, ZNF804A, is associated with brain white matter microstructure. Schizophr Res 2014; 155:15-20. [PMID: 24685285 PMCID: PMC4060886 DOI: 10.1016/j.schres.2014.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 02/27/2014] [Accepted: 03/01/2014] [Indexed: 01/03/2023]
Abstract
Genome-wide association studies have provided strong evidence for association of the SNP rs1344706 in the ZNF804A gene with schizophrenia and bipolar disorder. Neuroimaging studies have suggested that variation at rs1344706 may be associated with neural endophenotypes such as white matter volumes and densities. However, analyses of white matter microstructure using diffusion tensor imaging (DTI) have produced conflicting results. We examined the association between rs1344706 and white matter microstructure in 107 healthy individuals using tract-based spatial statistics (TBSS). TBSS analysis showed significant association between the risk allele and lower fractional anisotropy in the corpus callosum, left forceps minor, and right parietal white matter (p<.05; FWE corrected). Post-hoc analyses indicated that this association was largely driven by alterations in radial diffusivity, consistent with an effect of genotype on myelination. In light of the strong DTI evidence for white matter microstructural abnormalities in schizophrenia, the current results implicate a potential mechanism for schizophrenia risk formation by ZNF804A rs1344706 genotype.
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Guha S, Ayim F, Ludlow J, Sayasneh A, Condous G, Kirk E, Stalder C, Timmerman D, Bourne T, Van Calster B. Triaging pregnancies of unknown location: the performance of protocols based on single serum progesterone or repeated serum hCG levels. Hum Reprod 2014; 29:938-45. [DOI: 10.1093/humrep/deu045] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Xu C, Wallace MB, Yang J, Jiang L, Zhai Q, Zhang Y, Hong C, Chen Y, Frank TS, Stauffer JA, Asbun HJ, Raimondo M, Woodward TA, Li Z, Guha S, Zheng L, Li M. ZIP4 is a novel diagnostic and prognostic marker in human pancreatic cancer: a systemic comparison between EUS-FNA and surgical specimens. Curr Mol Med 2014; 14:309-15. [PMID: 24345208 PMCID: PMC6870177 DOI: 10.2174/1566524013666131217112921] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 12/11/2013] [Accepted: 12/12/2013] [Indexed: 12/31/2022]
Abstract
Aberrant expression of a zinc transporter ZIP4 in pancreatic ductal adenocarcinoma (PDAC) has been shown to contribute to tumor progression and is a potential target for individualized therapy. The overall objective of this study was to determine whether ZIP4 could serve as a novel diagnostic and prognostic marker in human PDAC, and if it can be assessed by minimally invasive sampling using endoscopic ultrasound guided fine needle aspiration (EUS-FNA). Immunohistochemistry was performed to compare ZIP4 expression in the PDAC samples obtained from EUS-FNA and matched surgical tumors (parallel control). Samples were reported by sensitivity, specificity, and predictive values, all with 95% confidence intervals (CI). A total of 23 cases with both FNA and surgical specimens were evaluated. We found that ZIP4 was significantly overexpressed in tumor cells from both sets of samples. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ZIP4 for the diagnosis of PDAC were 72.9%, 72.5%, 76.1%, and 69.0% in EUS-FNA samples, and were 97.9%, 65.4%, 83.9%, and 94.4% in surgical specimens, respectively. The association between the positive rate of ZIP4 expression in FNA and surgical samples is statistically significant (P=0.0216). Both the intensity and percentage of ZIP4 positive cells from the surgical samples correlated significantly with tumor stage (P=0.0025 and P=0.0002). ZIP4 intensity level in FNA samples was significantly associated with tumor differentiation and patient survival. These results indicate that EUS-FNA is capable of non-operative detection of ZIP4, thus offering the potential to direct pre-operative detection and targeted therapy of PDAC.
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Guha S, Natarajan O, Murbach CG, Dinh J, Wilson EC, Cao M, Zou S, Dong Y. Supplement timing of cranberry extract plays a key role in promoting Caenorhabditis elegans healthspan. Nutrients 2014; 6:911-21. [PMID: 24566444 PMCID: PMC3942739 DOI: 10.3390/nu6020911] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 12/20/2013] [Accepted: 02/11/2014] [Indexed: 12/22/2022] Open
Abstract
Consumption of nutraceuticals is a major and potent dietary intervention for delaying aging. As the timing of administration is critical for the efficacy of bioactive compounds in medicine, the effectiveness of nutraceuticals may also be dramatically affected by the timing of supplementation. Cranberry exact (CBE), rich in polyphenols, is consumed as a nutraceutical, and possesses anti-aging properties. Here, we examined the influence of timing on the beneficial effects of CBE supplementation in C. elegans. The prolongevity effect of CBE in different aged worms, young adults, middle-age adults, and aged adults, was determined. Early-start intervention with CBE prolonged the remaining lifespan of worms of different ages more robustly than late-start intervention. The effectiveness of CBE on stress responses and physiological behaviors in different aged worms was also investigated. The early-start intervention prominently promoted motility and resistance to heat shocks and V. cholera infection, especially in aged worms. Together, these findings suggest that the timing of CBE supplementation critically influences its beneficial effects on C. elegans lifespan and healthspan. It is of interest to further investigate whether the similar results would occur in humans.
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Capellini G, Reich C, Guha S, Yamamoto Y, Lisker M, Virgilio M, Ghrib A, El Kurdi M, Boucaud P, Tillack B, Schroeder T. Tensile Ge microstructures for lasing fabricated by means of a silicon complementary metal-oxide-semiconductor process. OPTICS EXPRESS 2014; 22:399-410. [PMID: 24515000 DOI: 10.1364/oe.22.000399] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this work we study, using experiments and theoretical modeling, the mechanical and optical properties of tensile strained Ge microstructures directly fabricated in a state-of-the art complementary metal-oxide-semiconductor fabrication line, using fully qualified materials and methods. We show that these microstructures can be used as active lasing materials in mm-long Fabry-Perot cavities, taking advantage of strain-enhanced direct band gap recombination. The results of our study can be realistically applied to the fabrication of a prototype platform for monolithic integration of near infrared laser sources for silicon photonics.
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Guha S, Cao M, Kane RM, Savino AM, Zou S, Dong Y. The longevity effect of cranberry extract in Caenorhabditis elegans is modulated by daf-16 and osr-1. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1559-74. [PMID: 22864793 PMCID: PMC3776105 DOI: 10.1007/s11357-012-9459-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/11/2012] [Indexed: 05/22/2023]
Abstract
Nutraceuticals are known to have numerous health and disease preventing properties. Recent studies suggest that extracts containing cranberry may have anti-aging benefits. However, little is known about whether and how cranberry by itself promotes longevity and healthspan in any organism. Here we examined the effect of a cranberry only extract on lifespan and healthspan in Caenorhabditis elegans. Supplementation of the diet with cranberry extract (CBE) increased the lifespan in C. elegans in a concentration-dependent manner. Cranberry also increased tolerance of C. elegans to heat shock, but not to oxidative stress or ultraviolet irradiation. In addition, we tested the effect of cranberry on brood size and motility and found that cranberry did not influence these behaviors. Our mechanistic studies indicated that lifespan extension induced by CBE requires the insulin/IGF signaling pathway and DAF-16. We also found that cranberry promotes longevity through osmotic stress resistant-1 (OSR-1) and one of its downstream effectors, UNC-43, but not through SEK-1, a component of the p38 MAP kinase pathway. However, SIR-2.1 and JNK signaling pathways are not required for cranberry to promote longevity. Our findings suggest that cranberry supplementation confers increased longevity and stress resistance in C. elegans through pathways modulated by daf-16 and osr-1. This study reveals the anti-aging property of widely consumed cranberry and elucidates the underpinning mechanisms.
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