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Papers by Isaac John

Frontiers in Cardiovascular Medicine

AimThe severity of cardiac impairment in acute heart failure (AHF) predicts outcome, but challeng... more AimThe severity of cardiac impairment in acute heart failure (AHF) predicts outcome, but challenges remain to identify prognostically important non-invasive parameters of cardiac function. Left ventricular ejection fraction (LVEF) is relevant, but only in those with reduced LV systolic function. We aimed to assess the standard and advanced parameters of left and right ventricular (RV) function from echocardiography in predicting long-term outcomes in AHF.MethodsA total of 418 consecutive AHF patients presenting over 12 months were prospectively recruited and underwent bedside echocardiography within 24 h of recruitment. We retrospectively assessed 8 RV and 5 LV echo parameters of the cardiac systolic function to predict 2-year mortality, using both guideline-directed and study-specific cutoffs, based on the maximum Youden indices via ROC analysis. For the RV, these were the tricuspid annular plane systolic excursion, RV fractional area change, tissue Doppler imaging (TDI) peak tricu...

BMJ Open, Apr 1, 2023

Objective To evaluate the clinical efficacy and safety of leflunomide (L) added to the standard-o... more Objective To evaluate the clinical efficacy and safety of leflunomide (L) added to the standard-of-care (SOC) treatment in COVID-19 patients hospitalised with moderate/critical clinical symptoms. Design Prospective, open-label, multicentre, stratified, randomised clinical trial. Setting Five hospitals in UK and India, from September 2020 to May 2021. Participants Adults with PCR confirmed COVID-19 infection with moderate/critical symptoms within 15 days of onset. Intervention Leflunomide 100 mg/day (3 days) followed by 10-20 mg/day (7 days) added to standard care. Primary outcomes The time to clinical improvement (TTCI) defined as two-point reduction on a clinical status scale or live discharge prior to 28 days; safety profile measured by the incidence of adverse events (AEs) within 28 days. Results Eligible patients (n=214; age 56.3±14.9 years; 33% female) were randomised to SOC+L (n=104) and SOC group (n=110), stratified according to their clinical risk profile. TTCI was 7 vs 8 days in SOC+L vs SOC group (HR 1.317; 95% CI 0.980 to 1.768; p=0.070). Incidence of serious AEs was similar between the groups and none was attributed to leflunomide. In sensitivity analyses, excluding 10 patients not fulfilling the inclusion criteria and 3 who withdrew consent before leflunomide treatment, TTCI was 7 vs 8 days (HR 1.416, 95% CI 1.041 to 1.935; p=0.028), indicating a trend in favour of the intervention group. Allcause mortality rate was similar between groups, 9/104 vs 10/110. Duration of oxygen dependence was shorter in the SOC+L group being a median 6 days (IQR 4-8) compared with 7 days (IQR 5-10) in SOC group (p=0.047). Conclusion Leflunomide, added to the SOC treatment for COVID-19, was safe and well tolerated but had no major impact on clinical outcomes. It may shorten the time of oxygen dependence by 1 day and thereby improve TTCI/ hospital discharge in moderately affected COVID-19 patients. Trial registration numbers EudraCT Number: 2020-002952-18, NCT05007678.

Diagnostics

Background: The prognostic impact of tricuspid regurgitation (TR) in acute heart failure (AHF) re... more Background: The prognostic impact of tricuspid regurgitation (TR) in acute heart failure (AHF) remains uncertain. Methods: We retrospectively assessed 418 consecutive AHF patients who underwent comprehensive echocardiographic assessment within 24 h of study recruitment. TR was quantitatively assessed with 3 guideline-directed measures: regurgitant volumes (RgVol), effective regurgitant orifice area (ERO) and vena contracta (VC) diameter. Disproportionate TR was assessed by the ratio of the VC diameter to the tricuspid annulus diameter (VC/TA) ≥ 0.24. Results: The prevalence of significant (i.e., >mild) TR differed when various standard assessment parameters were applied to quantification: RgVol 50.3% (173/344), ERO 75.6% (260/344) and VC diameter 94.6% (335/354). None were able to delineate those at excess risk of all-cause 2-year mortality using guideline-directed cut-offs of mild, moderate and severe TR. Using a cut-off of VC/TA ≥ 0.24, we identified that 36.9% (130/352) had “d...

Physiologia Plantarum, 1997

Senescence in plants is usually viewed as an internally programmed degeneration leading to death.... more Senescence in plants is usually viewed as an internally programmed degeneration leading to death. It is a developmental process that occurs in many different tissues and serves different purposes. Generally, apoptosis refers to programmed death of small numbers of animal cells, and it shows some special features at the cell level. Some senescing plant cells show some symptoms typical of apoptosis, while others do not. This review will focus primarily on leaf senescence with ultimate aim of explaining whole plant senescence (i.e., monocarpic senescence). Traditionally, the ideas on senescence mechanisms fall into two major groupings, nutrient deficiencies (e.g., starvation) and genetic programming (i.e., senescence-promoting and senescence-inhibiting genes). Considerable evidence indicates that nutrient deficiencies are not central senescence program components, while increasing evidence supports genetic programming. Because chlorophyll (Chl) and chloroplast (CP) breakdown are so pro...

Pakistan Journal of Agricultural Research, 1985

European Heart Journal, 2021

Background In acute heart failure (AHF) with moderate-range ejection fraction (HFmrEF) the effect... more Background In acute heart failure (AHF) with moderate-range ejection fraction (HFmrEF) the effect of mitral regurgitation (MR) is uncertain. Methods 103/440 consecutive patients in AHF had HFmrEF. They underwent bedside echocardiography within 24 hours of recruitment, prior to offloading, and were followed up for 2 years. The endpoint was all-cause mortality at 2 years. A novel proportionality index - where the effective regurgitant orifice is divided by the left ventricular end-diastolic volume (ERO/LVEDV)) - identified HFmrEF patients with disproportionate MR. Results 103/440 (23.4%) patients had HFmrEF with an average EF of 44.6±2.6%. 54.4% were male, with an average age of 80.5±11.4. 47.6% had a previous diagnosis of hypertension, 28.2% diabetes and 10.7% cerebrovascular disease. Patients did not present in shock, with average systolic/diastolic blood pressures of 141.7±26.2mmHg/ 78.5±19.3mmHg, nor did they primarily present with severe infections with mean CRP of 23.2±31.7. BNP...

European Heart Journal, 2021

Introduction The impact of tricuspid regurgitation (TR) on outcomes in acute heart failure (AHF) ... more Introduction The impact of tricuspid regurgitation (TR) on outcomes in acute heart failure (AHF) incompletely understood. Often TR is considered secondary to right ventricular (RV) remodelling and dysfunction, and it is not clear if the regurgitant volume itself has additional adverse effects on outcome. We hypothesised a novel index, where TR regurgitant volumes (TRRV [ml]) are divided by the RV end-diastolic volumes (RVEDV [ml]) may help to identify patients at risk of poor outcome. Purpose To identify a cut-off for disproportionate TR and to assess its impact on survival in AHF. Methods 418 consecutive patients admitted with AHF over 12 months to a single centre in the United Kingdom were recruited and followed up for 2 years. The endpoint was death from any cause. TR RV was calculated using the proximal isovelocity surface area method and right ventricular volumes using ellipsoid model. Receiver Operator Curve analyses were carried for the TRRV/RVEDV index. The optimum cut-off f...

European Heart Journal, 2021

Introduction Echocardiography (TTE) is an essential imaging modality for assessment of RV functio... more Introduction Echocardiography (TTE) is an essential imaging modality for assessment of RV function in acute heart failure. Established parameters are useful and easy to perform but fail to reflect on global volumes due to reliability on one acoustic window. It is therefore attractive to calculate RV volumes and ejection fraction using an ellipsoid model (RVEF/E) which has been validated against MRI in healthy adults but not in the HF patients. Purpose Predictive value of RVEF/E were compared with two established echo parameters of RV function over two-year follow-up period in patients with acute HF. Primary outcome measure was all-cause mortality. Methods Prospective cross-sectional study enrolling 418 consecutive patients with symptoms of acute HF according to a predefined study protocol. All patients underwent TTE assessment of RV function using Tricuspid Annular Plane Systolic Excursion (TAPSE) and RV fractional area change (RVFAC) and RVEF/E. RV Volumes calculated using formula,...

Biotechnology in Agriculture and Forestry, 1987

In Solarium tuberosum L. Var. BF 15, it has been observed that initiation of callogenesis with su... more In Solarium tuberosum L. Var. BF 15, it has been observed that initiation of callogenesis with subsequent organogenesis in vitro from various explants depends very much on the physiology of seed tuber (incubation). Besides, the nature of the explants (segments of sprout, in vitro shoots and seed tuber) is also important in this regard. In the explants taken from the shoots in vitro, the internodes show a better response than the internodes taken directly from the sprouts of seed tuber. The excised nodes of the sprout prove better than their corresponding internodes and the fragments of the in vitro shoots are more apt to this phenomenon than portions of the seed tuber. There is, however, a certain degree of antagonism between the two categories of regenerated organs, i.e. the shoots and the roots.

Plant Cell Death Processes, 2004

Publisher Summary This chapter discusses causes of monocarpic senescence and senescence in polyca... more Publisher Summary This chapter discusses causes of monocarpic senescence and senescence in polycarpic plants and clones. Whole plant senescence is viewed primarily in terms of leaf senescence and it is measured mainly through chloroplastic parameters such as chlorophyll loss and decreased photosynthesis. In monocarpic plants where senescence and death closely follow reproductive development, the senescence (monocarpic senescence) is often controlled by the developing reproductive structures. In these cases, removal of the reproductive structures or prevention of their development usually prolongs the life of the plant. Monocarpic plants cease their vegetative growth fairly abruptly early in their reproductive phase. Conversely, the perennial polycarpic pattern requires continued vegetative growth. This prominent shift (diversion) in growth-related allocation of resources in monocarpy seems to be part of a reproductive strategy that optimizes reproductive output for the plants. This diversion/withdrawal is often quite prominent that leads to monocarpic senescence.

Plant Molecular Biology, 1997

A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize roo... more A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize root mRNAs. The predicted polypeptide has a calculated molecular mass of 66 975 Da, is largely hydrophilic, and contains 26 repeats of a motif the consensus sequence of which is RKATTSYG[S][D/E][D/E][D/E][D/E][P]. The function of the putative protein remains to be elucidated. The ZRP2 mRNA accumulates

Frontiers in Cardiovascular Medicine, 2021

Objectives: To assess the prevalence and impact of mitral regurgitation (MR) on survival in patie... more Objectives: To assess the prevalence and impact of mitral regurgitation (MR) on survival in patients presenting to hospital in acute heart failure (AHF) using traditional echocardiographic assessment alongside more novel indices of proportionality.Background: It remains unclear if the severity of MR plays a significant role in determining outcomes in AHF. There is also uncertainty as to the clinical relevance of indexing MR to left ventricular volumes. This concept of disproportionality has not been assessed in AHF.Methods: A total of 418 consecutive patients presenting in AHF over 12 months were recruited and followed up for 2 years. MR was quantitatively assessed within 24 h of recruitment. Standard proximal isovelocity surface area (PISA) and a novel proportionality index of effective regurgitant orifice/left ventricular end-diastolic volume (ERO/LVEDV) >0.14 mm2/ml were used to identify severe and disproportionate MR.Results: Every patient had MR. About 331/418 (78.9%) patien...

Journal of Experimental Botany, 1997

Seven melon varieties (Alpha, Delada, Marygold, Sirio, Topper, Tornado, and Viva) known to exhibi... more Seven melon varieties (Alpha, Delada, Marygold, Sirio, Topper, Tornado, and Viva) known to exhibit differences in their ripening behaviour were used in this study. The expression of mRNAs for ACC oxidase (MEL1) and phytoene synthase (MEL5), required for synthesis of ethylene and carotenoids, respectively, and two ripening-related cDNAs (MEL2 and MEL7), of unknown function, was examined and correlated with the development of colour and softening of fruits. The MEL2 and MEL7 mRNAs were present and accumulated in all varieties, indicating their importance in melon fruit ripening. The fruits of Delada and Marygold did not show any change in the colour of the flesh even at 50 daa (days after anthesis). All other varieties changed colour from green to orange between 25-30 daa. The phytoene synthase mRNA levels in most varieties seemed to be unrelated to change in fruit flesh colour. The firmness of all the fruits was reduced significantly between 25 and 40 daa. The expression of ACC oxidase mRNA showed the most variation among the different varities and was delayed in Sirio and undetectable in Marygold fruits even at 40 daa. Varieties with delayed expression of ACC oxidase mRNAs after anthesis also showed delayed softening during ripening. The prospects of genetic engineering and breeding for melon fruits with improved quality characteristics and extended storage life are discussed.

Plant Molecular Biology, 1997

A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize roo... more A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize root mRNAs. The predicted polypeptide has a calculated molecular mass of 66 975 Da, is largely hydrophilic, and contains 26 repeats of a motif the consensus sequence of which is RKATTSYG[S][D/E][D/E][D/E][D/E][P]. The function of the putative protein remains to be elucidated. The ZRP2 mRNA accumulates to the highest levels in young roots, and is also present in mature roots and stems of maize. Further analysis of young roots indicates that the lowest level of ZRP2 mRNA is near the root tip, with relatively high levels throughout the remainder of the root. In situ hybridization reveals that ZRP2 mRNA accumulates predominantely in the cortical parenchyma cells of the root. In vitro nuclear run-on transcription experiments indicate a dramatically higher level of zrp2 gene transcription in 3-day old roots than in 5-day old leaves. A zrp2 genomic clone, which includes the transcribed region and ...

Physiologia …, 2002

The 'stay-green' mutation cytG in soybean (Glycine max) par-tially inhibits the degrada... more The 'stay-green' mutation cytG in soybean (Glycine max) par-tially inhibits the degradation of the light-harvesting complex II (LHCII) and the associated chlorophyll during monocarpic senescence. cytG did not alter the breakdown of the cyto-chrome b6/f complex, thylakoid ...

Plant molecular biology, 1992

Isaac John 1, Huiqing Wang, Bruce M. Held, Eve Syrkin Wurtele and James T. Colbert * Department o... more Isaac John 1, Huiqing Wang, Bruce M. Held, Eve Syrkin Wurtele and James T. Colbert * Department of Botany, Iowa State University, Ames, Iowa 50011-1020, USA (* author for correspondence); 1present address: Department of Physiology and Environmental ...

Frontiers in Cardiovascular Medicine

AimThe severity of cardiac impairment in acute heart failure (AHF) predicts outcome, but challeng... more AimThe severity of cardiac impairment in acute heart failure (AHF) predicts outcome, but challenges remain to identify prognostically important non-invasive parameters of cardiac function. Left ventricular ejection fraction (LVEF) is relevant, but only in those with reduced LV systolic function. We aimed to assess the standard and advanced parameters of left and right ventricular (RV) function from echocardiography in predicting long-term outcomes in AHF.MethodsA total of 418 consecutive AHF patients presenting over 12 months were prospectively recruited and underwent bedside echocardiography within 24 h of recruitment. We retrospectively assessed 8 RV and 5 LV echo parameters of the cardiac systolic function to predict 2-year mortality, using both guideline-directed and study-specific cutoffs, based on the maximum Youden indices via ROC analysis. For the RV, these were the tricuspid annular plane systolic excursion, RV fractional area change, tissue Doppler imaging (TDI) peak tricu...

BMJ Open, Apr 1, 2023

Objective To evaluate the clinical efficacy and safety of leflunomide (L) added to the standard-o... more Objective To evaluate the clinical efficacy and safety of leflunomide (L) added to the standard-of-care (SOC) treatment in COVID-19 patients hospitalised with moderate/critical clinical symptoms. Design Prospective, open-label, multicentre, stratified, randomised clinical trial. Setting Five hospitals in UK and India, from September 2020 to May 2021. Participants Adults with PCR confirmed COVID-19 infection with moderate/critical symptoms within 15 days of onset. Intervention Leflunomide 100 mg/day (3 days) followed by 10-20 mg/day (7 days) added to standard care. Primary outcomes The time to clinical improvement (TTCI) defined as two-point reduction on a clinical status scale or live discharge prior to 28 days; safety profile measured by the incidence of adverse events (AEs) within 28 days. Results Eligible patients (n=214; age 56.3±14.9 years; 33% female) were randomised to SOC+L (n=104) and SOC group (n=110), stratified according to their clinical risk profile. TTCI was 7 vs 8 days in SOC+L vs SOC group (HR 1.317; 95% CI 0.980 to 1.768; p=0.070). Incidence of serious AEs was similar between the groups and none was attributed to leflunomide. In sensitivity analyses, excluding 10 patients not fulfilling the inclusion criteria and 3 who withdrew consent before leflunomide treatment, TTCI was 7 vs 8 days (HR 1.416, 95% CI 1.041 to 1.935; p=0.028), indicating a trend in favour of the intervention group. Allcause mortality rate was similar between groups, 9/104 vs 10/110. Duration of oxygen dependence was shorter in the SOC+L group being a median 6 days (IQR 4-8) compared with 7 days (IQR 5-10) in SOC group (p=0.047). Conclusion Leflunomide, added to the SOC treatment for COVID-19, was safe and well tolerated but had no major impact on clinical outcomes. It may shorten the time of oxygen dependence by 1 day and thereby improve TTCI/ hospital discharge in moderately affected COVID-19 patients. Trial registration numbers EudraCT Number: 2020-002952-18, NCT05007678.

Diagnostics

Background: The prognostic impact of tricuspid regurgitation (TR) in acute heart failure (AHF) re... more Background: The prognostic impact of tricuspid regurgitation (TR) in acute heart failure (AHF) remains uncertain. Methods: We retrospectively assessed 418 consecutive AHF patients who underwent comprehensive echocardiographic assessment within 24 h of study recruitment. TR was quantitatively assessed with 3 guideline-directed measures: regurgitant volumes (RgVol), effective regurgitant orifice area (ERO) and vena contracta (VC) diameter. Disproportionate TR was assessed by the ratio of the VC diameter to the tricuspid annulus diameter (VC/TA) ≥ 0.24. Results: The prevalence of significant (i.e., >mild) TR differed when various standard assessment parameters were applied to quantification: RgVol 50.3% (173/344), ERO 75.6% (260/344) and VC diameter 94.6% (335/354). None were able to delineate those at excess risk of all-cause 2-year mortality using guideline-directed cut-offs of mild, moderate and severe TR. Using a cut-off of VC/TA ≥ 0.24, we identified that 36.9% (130/352) had “d...

Physiologia Plantarum, 1997

Senescence in plants is usually viewed as an internally programmed degeneration leading to death.... more Senescence in plants is usually viewed as an internally programmed degeneration leading to death. It is a developmental process that occurs in many different tissues and serves different purposes. Generally, apoptosis refers to programmed death of small numbers of animal cells, and it shows some special features at the cell level. Some senescing plant cells show some symptoms typical of apoptosis, while others do not. This review will focus primarily on leaf senescence with ultimate aim of explaining whole plant senescence (i.e., monocarpic senescence). Traditionally, the ideas on senescence mechanisms fall into two major groupings, nutrient deficiencies (e.g., starvation) and genetic programming (i.e., senescence-promoting and senescence-inhibiting genes). Considerable evidence indicates that nutrient deficiencies are not central senescence program components, while increasing evidence supports genetic programming. Because chlorophyll (Chl) and chloroplast (CP) breakdown are so pro...

Pakistan Journal of Agricultural Research, 1985

European Heart Journal, 2021

Background In acute heart failure (AHF) with moderate-range ejection fraction (HFmrEF) the effect... more Background In acute heart failure (AHF) with moderate-range ejection fraction (HFmrEF) the effect of mitral regurgitation (MR) is uncertain. Methods 103/440 consecutive patients in AHF had HFmrEF. They underwent bedside echocardiography within 24 hours of recruitment, prior to offloading, and were followed up for 2 years. The endpoint was all-cause mortality at 2 years. A novel proportionality index - where the effective regurgitant orifice is divided by the left ventricular end-diastolic volume (ERO/LVEDV)) - identified HFmrEF patients with disproportionate MR. Results 103/440 (23.4%) patients had HFmrEF with an average EF of 44.6±2.6%. 54.4% were male, with an average age of 80.5±11.4. 47.6% had a previous diagnosis of hypertension, 28.2% diabetes and 10.7% cerebrovascular disease. Patients did not present in shock, with average systolic/diastolic blood pressures of 141.7±26.2mmHg/ 78.5±19.3mmHg, nor did they primarily present with severe infections with mean CRP of 23.2±31.7. BNP...

European Heart Journal, 2021

Introduction The impact of tricuspid regurgitation (TR) on outcomes in acute heart failure (AHF) ... more Introduction The impact of tricuspid regurgitation (TR) on outcomes in acute heart failure (AHF) incompletely understood. Often TR is considered secondary to right ventricular (RV) remodelling and dysfunction, and it is not clear if the regurgitant volume itself has additional adverse effects on outcome. We hypothesised a novel index, where TR regurgitant volumes (TRRV [ml]) are divided by the RV end-diastolic volumes (RVEDV [ml]) may help to identify patients at risk of poor outcome. Purpose To identify a cut-off for disproportionate TR and to assess its impact on survival in AHF. Methods 418 consecutive patients admitted with AHF over 12 months to a single centre in the United Kingdom were recruited and followed up for 2 years. The endpoint was death from any cause. TR RV was calculated using the proximal isovelocity surface area method and right ventricular volumes using ellipsoid model. Receiver Operator Curve analyses were carried for the TRRV/RVEDV index. The optimum cut-off f...

European Heart Journal, 2021

Introduction Echocardiography (TTE) is an essential imaging modality for assessment of RV functio... more Introduction Echocardiography (TTE) is an essential imaging modality for assessment of RV function in acute heart failure. Established parameters are useful and easy to perform but fail to reflect on global volumes due to reliability on one acoustic window. It is therefore attractive to calculate RV volumes and ejection fraction using an ellipsoid model (RVEF/E) which has been validated against MRI in healthy adults but not in the HF patients. Purpose Predictive value of RVEF/E were compared with two established echo parameters of RV function over two-year follow-up period in patients with acute HF. Primary outcome measure was all-cause mortality. Methods Prospective cross-sectional study enrolling 418 consecutive patients with symptoms of acute HF according to a predefined study protocol. All patients underwent TTE assessment of RV function using Tricuspid Annular Plane Systolic Excursion (TAPSE) and RV fractional area change (RVFAC) and RVEF/E. RV Volumes calculated using formula,...

Biotechnology in Agriculture and Forestry, 1987

In Solarium tuberosum L. Var. BF 15, it has been observed that initiation of callogenesis with su... more In Solarium tuberosum L. Var. BF 15, it has been observed that initiation of callogenesis with subsequent organogenesis in vitro from various explants depends very much on the physiology of seed tuber (incubation). Besides, the nature of the explants (segments of sprout, in vitro shoots and seed tuber) is also important in this regard. In the explants taken from the shoots in vitro, the internodes show a better response than the internodes taken directly from the sprouts of seed tuber. The excised nodes of the sprout prove better than their corresponding internodes and the fragments of the in vitro shoots are more apt to this phenomenon than portions of the seed tuber. There is, however, a certain degree of antagonism between the two categories of regenerated organs, i.e. the shoots and the roots.

Plant Cell Death Processes, 2004

Publisher Summary This chapter discusses causes of monocarpic senescence and senescence in polyca... more Publisher Summary This chapter discusses causes of monocarpic senescence and senescence in polycarpic plants and clones. Whole plant senescence is viewed primarily in terms of leaf senescence and it is measured mainly through chloroplastic parameters such as chlorophyll loss and decreased photosynthesis. In monocarpic plants where senescence and death closely follow reproductive development, the senescence (monocarpic senescence) is often controlled by the developing reproductive structures. In these cases, removal of the reproductive structures or prevention of their development usually prolongs the life of the plant. Monocarpic plants cease their vegetative growth fairly abruptly early in their reproductive phase. Conversely, the perennial polycarpic pattern requires continued vegetative growth. This prominent shift (diversion) in growth-related allocation of resources in monocarpy seems to be part of a reproductive strategy that optimizes reproductive output for the plants. This diversion/withdrawal is often quite prominent that leads to monocarpic senescence.

Plant Molecular Biology, 1997

A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize roo... more A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize root mRNAs. The predicted polypeptide has a calculated molecular mass of 66 975 Da, is largely hydrophilic, and contains 26 repeats of a motif the consensus sequence of which is RKATTSYG[S][D/E][D/E][D/E][D/E][P]. The function of the putative protein remains to be elucidated. The ZRP2 mRNA accumulates

Frontiers in Cardiovascular Medicine, 2021

Objectives: To assess the prevalence and impact of mitral regurgitation (MR) on survival in patie... more Objectives: To assess the prevalence and impact of mitral regurgitation (MR) on survival in patients presenting to hospital in acute heart failure (AHF) using traditional echocardiographic assessment alongside more novel indices of proportionality.Background: It remains unclear if the severity of MR plays a significant role in determining outcomes in AHF. There is also uncertainty as to the clinical relevance of indexing MR to left ventricular volumes. This concept of disproportionality has not been assessed in AHF.Methods: A total of 418 consecutive patients presenting in AHF over 12 months were recruited and followed up for 2 years. MR was quantitatively assessed within 24 h of recruitment. Standard proximal isovelocity surface area (PISA) and a novel proportionality index of effective regurgitant orifice/left ventricular end-diastolic volume (ERO/LVEDV) >0.14 mm2/ml were used to identify severe and disproportionate MR.Results: Every patient had MR. About 331/418 (78.9%) patien...

Journal of Experimental Botany, 1997

Seven melon varieties (Alpha, Delada, Marygold, Sirio, Topper, Tornado, and Viva) known to exhibi... more Seven melon varieties (Alpha, Delada, Marygold, Sirio, Topper, Tornado, and Viva) known to exhibit differences in their ripening behaviour were used in this study. The expression of mRNAs for ACC oxidase (MEL1) and phytoene synthase (MEL5), required for synthesis of ethylene and carotenoids, respectively, and two ripening-related cDNAs (MEL2 and MEL7), of unknown function, was examined and correlated with the development of colour and softening of fruits. The MEL2 and MEL7 mRNAs were present and accumulated in all varieties, indicating their importance in melon fruit ripening. The fruits of Delada and Marygold did not show any change in the colour of the flesh even at 50 daa (days after anthesis). All other varieties changed colour from green to orange between 25-30 daa. The phytoene synthase mRNA levels in most varieties seemed to be unrelated to change in fruit flesh colour. The firmness of all the fruits was reduced significantly between 25 and 40 daa. The expression of ACC oxidase mRNA showed the most variation among the different varities and was delayed in Sirio and undetectable in Marygold fruits even at 40 daa. Varieties with delayed expression of ACC oxidase mRNAs after anthesis also showed delayed softening during ripening. The prospects of genetic engineering and breeding for melon fruits with improved quality characteristics and extended storage life are discussed.

Plant Molecular Biology, 1997

A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize roo... more A near full-length cDNA clone (pZRP2) was isolated from a cDNA library constructed from maize root mRNAs. The predicted polypeptide has a calculated molecular mass of 66 975 Da, is largely hydrophilic, and contains 26 repeats of a motif the consensus sequence of which is RKATTSYG[S][D/E][D/E][D/E][D/E][P]. The function of the putative protein remains to be elucidated. The ZRP2 mRNA accumulates to the highest levels in young roots, and is also present in mature roots and stems of maize. Further analysis of young roots indicates that the lowest level of ZRP2 mRNA is near the root tip, with relatively high levels throughout the remainder of the root. In situ hybridization reveals that ZRP2 mRNA accumulates predominantely in the cortical parenchyma cells of the root. In vitro nuclear run-on transcription experiments indicate a dramatically higher level of zrp2 gene transcription in 3-day old roots than in 5-day old leaves. A zrp2 genomic clone, which includes the transcribed region and ...

Physiologia …, 2002

The 'stay-green' mutation cytG in soybean (Glycine max) par-tially inhibits the degrada... more The 'stay-green' mutation cytG in soybean (Glycine max) par-tially inhibits the degradation of the light-harvesting complex II (LHCII) and the associated chlorophyll during monocarpic senescence. cytG did not alter the breakdown of the cyto-chrome b6/f complex, thylakoid ...

Plant molecular biology, 1992

Isaac John 1, Huiqing Wang, Bruce M. Held, Eve Syrkin Wurtele and James T. Colbert * Department o... more Isaac John 1, Huiqing Wang, Bruce M. Held, Eve Syrkin Wurtele and James T. Colbert * Department of Botany, Iowa State University, Ames, Iowa 50011-1020, USA (* author for correspondence); 1present address: Department of Physiology and Environmental ...