156 results on '"Hatem C"'
Search Results
52. Performance Characteristics of 65nm PFETs Using Molecular Implant Species for Source and Drain Extensions
- Author
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Tan, Chung Foong, primary, Teo, L. W., additional, Yin, C-S., additional, Lee, J. G., additional, Liu, J., additional, See, A., additional, Zhou, M. S., additional, Quek, E., additional, Chu, S., additional, Hatem, C., additional, Variam, N., additional, Arevalo, E., additional, Gupta, A., additional, and Mehta, S., additional
- Published
- 2008
- Full Text
- View/download PDF
53. What are the results of hepatitis C treatment in a general population?
- Author
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Hatem, C., primary, Minello, A., additional, Bresson-Hadni, S., additional, Jooste, V., additional, Evrard, P., additional, Gossard, A.C., additional, Obert, B., additional, Rassiat, E., additional, Milan, C., additional, Bonithon-Kopp, C., additional, Faivre, J., additional, Monnet, E., additional, Miguet, J.P., additional, Lepage, C., additional, and Hillon, P., additional
- Published
- 2003
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54. Effect of Wheat Monoculture on Durum Wheat Yield under Rainfed Sub-Humid Mediterranean Climate of Tunisia
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Asma Bouatrous, Kalthoum Harbaoui, Chahine Karmous, Samia Gargouri, Amir Souissi, Karima Belguesmi, Hatem Cheikh Mhamed, Mohamed Salah Gharbi, and Mohamed Annabi
- Subjects
durum wheat ,grain yield ,previous-crop ,quality ,stability ,Agriculture - Abstract
Cultivating cereals in monoculture systems contributes to the decrease in grain yield and quality. Currently, under Mediterranean climate conditions of Tunisia, wheat mono-cropping covers more than 70% of cereal areas. In order to reveal the impact of this practice on cereal productivity, five improved durum wheat cultivars (Karim, Khiar, Om Rabiaa, Razzek, and Maali) were conducted under two conditions of previous wheat crop: one-year wheat previous crop (W) and two successive years (W-W). Then, they were assessed for grain yield (GY), yield components (NKS, TKW, NS), straw yield, harvest index (SY, HI), and grain quality parameters during three consecutive cropping seasons (2017, 2018, and 2019). The results showed significant effects of cropping season for all measured parameters, except thousand kernel weight (TKW). A significant effect (p < 0.05) of Pre-Crop was observed on yield components. However, grain yield (GY) was improved after one-year wheat Pre-Crop (W) (4082.3 kg ha−1) more than after two years (W-W) (3277.3 kg ha−1). Our results show that, based on the three-year experiment, almost all yield related traits were significantly affected by the genotype except HI and NS. The highest GYs were recorded for Om Rabiaa (4010.4 kg ha−1) and Nasr (3765.76 kg ha−1). All grain quality was significantly (p < 0.05) affected by cropping season, but only gluten content (GC) and vitreousness aspect (Vit A) were affected by genotype. On the other hand, the Pre-Crop W-W decreased grain protein concentration (GPC) (12.13%) and GC (22.14%) but no significant effect was observed on the Vit A of grain in our study. Furthermore, GY was positively correlated with HI (r = 0.64), NKS (r = 0.59), SN (r = 0.49), GPC (r = 0.23), and GC (r = 0.23). According to stability analysis, the Karim cultivar is the most stable genotype in wheat mono-cropping for GY and straw yield (SY). Altogether, this study provides useful information for farmers on how to produce a satisfactory yield for durum wheat cultivation under mono-cropping wheat conditions in the sub-humid environment of the Mediterranean climate of Tunisia.
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- 2022
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55. Long Term Effects of Tillage–Crop Rotation Interaction on Soil Organic Carbon Pools and Microbial Activity on Wheat-Based System in Mediterranean Semi-Arid Region
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Sayda Jaziri, Hatem Cheikh M’hamed, Mohsen Rezgui, Sonia Labidi, Amir Souissi, Mounir Rezgui, Mariem Barbouchi, Mohamed Annabi, and Haithem Bahri
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tillage-rotation interaction ,soil organic carbon pools ,soil microbial activity ,Mediterranean environment ,Agriculture - Abstract
Conservation agriculture based on no-tillage (NT) and crop rotation allows to enhance soil health. Based on data collected from long-term trials in a semi-arid region of Tunisia, results showed that NT increased significantly soil organic carbon stock (SOCS), soil microbial biomass carbon (SMBC), arbuscular mycorrhizal fungal (AMF) root colonization, and soil microbial respiration (CO2) at 0–20 cm topsoil layer compared to conventional tillage (CT). Moreover, triennial rotation (TRI), based on annual succession of Faba bean-Durum wheat-Barley, and biennial rotation (BI), based on annual succession of Faba bean-Durum wheat, increased significatively SMBC, AMF, and CO2. Likewise, a significant benefit of the two-way interactions Tillage × Rotation was observed. Furthermore, NT combined with TRI recorded the highest SOCS (2181 g C m−2), SMBC (515 mg C kg−1 soil), AMF (14%), and CO2 which is an indicator of soil microbial respiration (1071 mg CO2 kg−1 soil). The current results highlight the benefit adoption of minimum or (NT)combined with crop diversification on soil health.
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- 2022
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56. Performance Characteristics of 65nm PFETs Using Molecular Implant Species for Source and Drain Extensions.
- Author
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Tan, C. F., Teo, L. W., Yin, C-S, Lee, J. G., Liu, J., See, A., Zhou, M. S., Quek, E., Chu, S., Hatem, C., Variam, N., Arevalo, E., Gupta, A., and Mehta, S.
- Published
- 2008
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57. Precision ion implantation: A critical tool for advanced device processing.
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Gossmann, H.-J.L., Thanigaivelan, T., and Hatem, C.
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- 2008
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58. New Approaches to Ultra Shallow Junction Formation by Molecular Implantation and Millisecond Laser Spike Annealing.
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Variam, N., Kontos, A., Arevalo, E., Hatem, C., Shaoyin Chen, and Yun Wang
- Published
- 2007
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59. Morpho-physiological and molecular responses of two Libyan bread wheat cultivars to plant growth regulators under salt stress
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El Hadi Hadia, Amor Slama, Leila Romdhane, Hatem Cheikh M’hamed, Ahmed Houssein Abodoma, Mohamed Ali Saed Fahej, and Leila Radhouane
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Libyan bread wheat ,glycine betaine ,ribulose biphosphate carboxylase ,phosphoenolpyruvate carboxylase ,plant growth regulator ,salinity. ,Agriculture ,Plant culture ,SB1-1110 - Abstract
To study the effects of salt stress and plant growth regulators (kinetin, gibberellic acid, potassium) on growth, yield, glycine betaine content, phosphoenolpyruvate carboxylase (PEPC) and ribulose biphosphate carboxylase (RBC) gene expression of two Libyan bread wheat varieties, a factorial design of greenhouse experiment with three replications was conducted. Results revealed that salt stress significantly reduced plant growth and productivity of both varieties. Moreover, the addition of kinetin + potassium and gibberellic acid + potassium had improved the performance of the morpho-metric parameters of both genotypes under salt stress; but the performance was more effective for kinetin treatment than for gibberellic acid. At the biochemical level, the results showed that salt stress increased glycine betaine contents in both varieties with different proportions. This increase is more elevated in the presence of kinetin + potassium than the treatment with gibberellic acid+ potassium, which showed an almost similar result as in only salt stress. At the molecular level, the effects of salt stress and plant growth regulators on the PEPC and RBC gene expression showed that the increase was significantly higher for kinetin, gibberellic acid, and salt stress when compared to the control.
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- 2020
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60. Higher temperatures and lower annual rainfall do not restrict, directly or indirectly, the mycorrhizal colonization of barley (Hordeum vulgare L.) under rainfed conditions.
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Maroua Jerbi, Sonia Labidi, Anissa Lounès-Hadj Sahraoui, Hatem Chaar, and Faysal Ben Jeddi
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Medicine ,Science - Abstract
Whereas the role of arbuscular mycorrhizal fungi (AMF) in plant growth improvement has been well described in agroecosystems, little is known about the effect of environmental factors on AMF root colonization status of barley, the fourth most important cereal crop all over the world. In order to understand the influence of environmental factors, such as climatic and soil physico-chemical properties, on the spontaneous mycorrhizal ability of barley (Hordeum vulgare L.), a field investigation was conducted in 31 different sites in sub-humid, upper and middle semi-arid areas of Northern Tunisia. Mycorrhizal root colonization of H. vulgare varied considerably among sites. Principal component analysis showed that barley mycorrhization is influenced by both climatic and edaphic factors. A partial least square structural equation modelling (PLS-SEM) revealed that 39% (R²) of the total variation in AMF mycorrhizal rate of barley roots was mainly explained by chemical soil properties and climatic characteristics. Whereas barley root mycorrhizal rates were inversely correlated with soil organic nitrogen (ON), available phosphorus amounts (P), altitude (Z), average annual rainfall (AAR), they were directly correlated with soil pH and temperature. Our results indicated that AMF root colonization of barley was strongly related to climatic characteristics than chemical soil properties. The current study highlights the importance of the PLS-SEM to understand the interactions between climate, soil properties and AMF symbiosis of barley in field conditions.
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- 2020
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61. The Potential of Using Radarsat-2 Satellite Image for Modeling and Mapping Wheat Yield in a Semiarid Environment
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Meriem Barbouchi, Rachid Lhissou, Riadh Abdelfattah, Anas El Alem, Karem Chokmani, Nadhira Ben Aissa, Hatem Cheikh M’hamed, Mohamed Annabi, and Haithem Bahri
- Subjects
PolSAR ,backscattering ,polarimetric parameters ,multiple regression ,remote sensing ,Agriculture (General) ,S1-972 - Abstract
The monitoring of cereal productions, mainly through yield estimations, has played an important role in providing reliable information to decision makers in order to ensure the proper management of agricultural markets. In this context, remote sensing, which allows the coverage of large areas, is an important source of information that complements those obtained by other methods. In this study, we aim to estimate the wheat yield at an early growth stage (spring season) using only one Radarsat-2 (RS-2) polarimetric image. We propose an empirical statistical relationship between the yield measured in situ and polarimetric parameters extracted from the RS-2 image. The RS-2 image was acquired at the flowering stage as it is proved to be the most appropriate moment for yield prediction. We selected the region of Boussalem in the northwest of Tunisia as the study area. For experimental validation, the yield was determined in situ at the end of the wheat season. Results showed that the polarization ratios are more correlated than the polarimetric parameters with the grain yield with a significant correlation of the HH/VV ratio (r = 0.76) and the HV/VV ratio (r = −0.75), while the most correlated polarimetric parameter was Alpha (r = −0.51). Finally, the multiple regression has led to the development of a three-variable model (HH/VV, HV/HH, and alpha) as the best predictor of the wheat grain yields. Validation results revealed a great potential with a determination coefficient (R2) of 0.58 and root mean squared error (RMSE) of 0.89 t/ha.
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- 2022
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62. The incidence of infectious complications of central venous catheters at the subclavian, internal jugular, and femoral sites in an intensive care unit population.
- Author
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Deshpande KS, Hatem C, Ulrich HL, Currie BP, Aldrich TK, Bryan-Brown CW, Kvetan V, Deshpande, Kedar S, Hatem, Carlo, Ulrich, Harry L, Currie, Brian P, Aldrich, Thomas K, Bryan-Brown, Christopher W, and Kvetan, Vladimir
- Abstract
Objective: The objective was to assess the risk of central venous catheter infection with respect to the site of insertion in an intensive care unit population. The subclavian, internal jugular, and femoral sites were studied.Design: An epidemiologic, prospective, observational study.Setting: The setting is a well-functioning intensive care unit under a unified critical care medicine division in a university teaching hospital. Critical care medicine attendings and fellows covered on site 17 and 24 hrs per day, respectively.Patients: Patients were critically ill. All patients were triaged into the intensive care unit by on-site critical care medicine fellows.Interventions: None.Measurements and Main Results: In an intensive care unit population, we prospectively studied the incidence of central venous catheter infection and colonization at the subclavian, internal jugular, and femoral sites. The optimal insertion site for each individual patient was selected by experienced intensive care physicians (critical care medicine attendings and fellows). All of the operators were proficient in inserting catheters at all three sites. Confounding factors were eliminated; there were a limited number of experienced operators inserting the catheters, a uniform protocol stressing strict sterile insertion was enforced, and standardized continuous catheter care was provided by dedicated intensive care nurses proficient in all aspects of central venous catheter care. Two groups of patients were analyzed. Group 1 was patients with one catheter at one site, and group 2 was patients with catheters at multiple sites. Group 1 was the primary analysis, whereas group 2 was supporting.A total of 831 central venous catheters and 4,735 catheter days in 657 patients were studied. The incidence of catheter infection (4.01/1,000 catheter days, 2.29% catheters) and colonization (5.07/1,000 catheter days, 2.89% catheters) was low overall. In group 1, the incidence of infection was subclavian: 0.881 infections/1,000 catheter days (0.45%), internal jugular: 0/1,000 (0%), and femoral: 2.98/1,000 (1.44%; p = .2635). The incidence of colonization was subclavian: 0.881 colonization/1,000 catheter days (0.45%), internal jugular: 2.00/1,000 (1.05%), and femoral: 5.96/1,000 (2.88%, p = .1338). There was no statistically significant difference in the incidence of infection and colonization or duration of catheters (p = .8907) among the insertion sites. In group 2, there was also no statistically significant difference in the incidence of infection and colonization among the three insertion sites.Conclusion: In an intensive care unit population, the incidence of central venous catheter infection and colonization is low overall and, clinically and statistically, is not different at all three sites when optimal insertion sites are selected, experienced operators insert the catheters, strict sterile technique is present, and trained intensive care unit nursing staff perform catheter care. [ABSTRACT FROM AUTHOR]- Published
- 2005
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63. Incidence and management of malignant digestive endocrine tumours in a well defined french population.
- Author
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Lepoge, C, Bowler, A M, Phelip, J M, Hatem, C, and Vemet, C
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ENDOCRINE diseases ,METASTASIS ,DIGESTIVE organ cancer ,CARCINOID ,DIAGNOSIS - Abstract
Background and aims: Little is known about the epidemiology of malignant digestive endocrine tumours. The aim of this study was to report on their incidence and management in a well defined population. Methods: Data were obtained from the population based Digestive Cancer Registry of Burgundy (France) over a 24 year period. Incidence rates were calculated by sex, age groups, and period of diagnosis. Treatment and stage at diagnosis were also investigated. Prognosis was determined using crude and relative survival rates. A multivariate relative survival analysis was performed. Results: Between 1976 and 1999, 229 cases were recorded. Age standardised incidence rates were 0.76/100 000 for men and 0.50/100 000 for women. They increased over time in both sexes. The resectability rate was 74.1 %. Among recorded cases, 26.6% did not extend beyond the organ, 20% had lymph node metastases, and 53.3% had visceral metastases or were unresectable. There was no improvement in the resection rate or in the stage at diagnosis over the study period. The overall relative survival rate was 66.9% at one year, 50.4% at five years, and 40.6% at 10 years. Stage at diagnosis, age at diagnosis, and subsite were independent significant prognostic factors. Conclusions: Although their incidence is increasing, malignant digestive endocrine tumours remain a rare cancer, representing 1 % of digestive cancers. Stage at diagnosis and prognosis at a population level are worse than those reported in hospital series. In the short term, new therapeutic possibilities represent the best way to improve their prognosis. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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64. Incidence of Fusarium foot and root rot of cereals under conservation agriculture in north west Tunisia
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Samira CHEKALI, Samia GARGOURI, Moncef BEN HAMMOUDA, Hatem Cheikh M’HAMED, and Bouzid NASRAOUI
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direct drilling ,conventional drilling ,Fusarium foot and root rot ,cereals ,Botany ,QK1-989 - Abstract
Conservation agriculture, based on direct drilling for crop establishment, has emerged in Tunisia since 1999/2000 as an alternative to conventional agriculture based on conventional drilling. The main objective of this approach is to ensure yield stability from crops and replenishment of soil organic matter. Previous research has demonstrated increased risks from pathogens favoured by mulching. The impacts of direct drilling on yields, and Fusarium foot and root rot of durum wheat, oat and barley, were studied over three successive growing seasons (2009/10, 2010/11, 2011/12) in northwest Tunisia. Disease incidence was estimated by the recovery frequency of Fusarium spp. isolates from stem bases and roots of plants of the three cereals. In addition, disease severity was assessed by occurrence of whiteheads that senesced prematurely, and the browning intensity on durum wheat stem bases. Grain yields were recorded at the ripening stages. Fusarium culmorum and F. pseudograminearum were isolated from the three cereals, with F. culmorum being the dominant pathogen. Direct drilling increased the incidence (60%) of these pathogens on stem bases and roots during the warmer seasons of 2009/10 and 2010/11, but less infection (37%) compared to conventional drilling was observed in the wetter season of 2011/12. Direct drilling increased the percentage of whiteheads of durum wheat (73%), but did not affect disease severity, which was estimated by the discolouration on stem bases and grain yield.
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- 2019
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65. Fungal X-Intrinsic Protein Aquaporin from Trichoderma atroviride: Structural and Functional Considerations
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Maroua Ben Amira, Mohamed Faize, Magnus Karlsson, Mukesh Dubey, Magdalena Frąc, Jacek Panek, Boris Fumanal, Aurélie Gousset-Dupont, Jean-Louis Julien, Hatem Chaar, Daniel Auguin, Robin Mom, Philippe Label, and Jean-Stéphane Venisse
- Subjects
aquaporin ,uncharacterized X-Intrinsic proteins ,Trichoderma atroviride ,3D modeling ,chlamydospores ,pentose phosphate pathway ,Microbiology ,QR1-502 - Abstract
The major intrinsic protein (MIP) superfamily is a key part of the fungal transmembrane transport network. It facilitates the transport of water and low molecular weight solutes across biomembranes. The fungal uncharacterized X-Intrinsic Protein (XIP) subfamily includes the full protein diversity of MIP. Their biological functions still remain fully hypothetical. The aim of this study is still to deepen the diversity and the structure of the XIP subfamily in light of the MIP counterparts—the aquaporins (AQPs) and aquaglyceroporins (AQGPs)—and to describe for the first time their function in the development, biomass accumulation, and mycoparasitic aptitudes of the fungal bioagent Trichoderma atroviride. The fungus-XIP clade, with one member (TriatXIP), is one of the three clades of MIPs that make up the diversity of T. atroviride MIPs, along with the AQPs (three members) and the AQGPs (three members). TriatXIP resembles those of strict aquaporins, predicting water diffusion and possibly other small polar solutes due to particularly wider ar/R constriction with a Lysine substitution at the LE2 position. The XIP loss of function in ∆TriatXIP mutants slightly delays biomass accumulation but does not impact mycoparasitic activities. ∆TriatMIP forms colonies similar to wild type; however, the hyphae are slightly thinner and colonies produce rare chlamydospores in PDA and specific media, most of which are relatively small and exhibit abnormal morphologies. To better understand the molecular causes of these deviant phenotypes, a wide-metabolic survey of the ∆TriatXIPs demonstrates that the delayed growth kinetic, correlated to a decrease in respiration rate, is caused by perturbations in the pentose phosphate pathway. Furthermore, the null expression of the XIP gene strongly impacts the expression of four expressed MIP-encoding genes of T. atroviride, a plausible compensating effect which safeguards the physiological integrity and life cycle of the fungus. This paper offers an overview of the fungal XIP family in the biocontrol agent T. atroviride which will be useful for further functional analysis of this particular MIP subfamily in vegetative growth and the environmental stress response in fungi. Ultimately, these findings have implications for the ecophysiology of Trichoderma spp. in natural, agronomic, and industrial systems.
- Published
- 2021
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66. Estimation of Tunisian Greenhouse Gas Emissions from Different Livestock Species
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Hajer Ammar, Sourour Abidi, Mediha Ayed, Nizar Moujahed, Mario E. deHaro Martí, Mireille Chahine, Rachid Bouraoui, Secundino López, Hatem Cheikh M’hamed, and Haikel Hechlef
- Subjects
livestock ,enteric fermentation ,manure management ,methane ,nitrous oxide ,emission factor ,Agriculture (General) ,S1-972 - Abstract
This study aimed to determine the emissions of methane (CH4) and nitrous oxide (N2O) from seven Tunisian livestock species and their evolution over eleven consecutive years (2008–2018). The species of animals used were cattle (dairy and others), sheep, goats, camelids, horses, donkeys and mules, and poultry. The estimations of CH4 and N2O emissions were based on the Intergovernmental Panel on Climate Change (IPCC) guidelines for national inventories, using Tier 1 and Tier 2 approaches, with its default emission factors (EFs). The Tier 2 approach was applied only for the calculation of EF to estimate CH4 emissions related to livestock manure management. CH4 emission represented more than 92% of the total greenhouse gas (GHG) from livestock emissions. Moreover, 53% of the total CH4 emissions from livestock were derived from cattle, followed by sheep, goats, other mammals (camelids, horses, mules, and donkeys), and poultry. During the period covered by the study (2008–2018), a slight and continuous decrease of both livestock population and total GHG emissions was observed, mainly in terms of CH4. In mammals, CH4 emissions were greater than N2O emissions, whereas in poultry, N2O emissions were up to 2.6 times greater than CH4 emissions. The aggressive drive of the government to increase cattle and sheep production might affect CH4 emissions in the future. Therefore, periodic estimations of GHG emissions from livestock are required to follow the time trends for more rational decision-making regarding livestock and GHG emissions policies.
- Published
- 2020
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67. Effect of Tillage, Previous Crop, and N Fertilization on Agronomic and Economic Performances of Durum Wheat (Triticum durum Desf.) under Rainfed Semi-Arid Environment
- Author
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Amir Souissi, Haithem Bahri, Hatem Cheikh M’hamed, Mohamed Chakroun, Salah Benyoussef, Ayman Frija, and Mohamed Annabi
- Subjects
durum wheat ,crop yield ,nitrogen-use efficiency ,water-use efficiency ,gross margins ,conservation agriculture ,Agriculture - Abstract
The implementation of conservation agriculture (CA) remains crucial for facing interannual variability in climatic conditions that impact durum wheat production and food security. The current work was conducted to assess the effects of the tillage practice, previous crop, and nitrogen (N) fertilization rate on the agronomic and economic performances of rainfed durum wheat in a semi-arid environment in Tunisia. Tillage practices included no-tillage (NT) and conventional tillage (CT). Preceding crops were either a common vetch or a bread wheat. The N rates applied were: 0, 75, 100, 120, and 140 kg N ha−1. Our results show that, based on a 2-year experiment, tillage practices are not affecting grain yield, grain N, and gross margins. However, the N-use efficiency of durum wheat was significantly higher when wheat was grown using NT. Grain yield and N content in grain were 340 kg ha−1 and 0.34%; much higher after vetch than after bread wheat. For both tillage practices, the merit of 75 kg N ha−1 is paramount to maximize yield through a more efficient use of available N. Our results highlight the importance of no-tillage-based CA combined with rotation, including vetch, on enhanced yields, N-use efficiency, and gross margins. These findings provide the evidence of the positive impact of CA for rainfed durum wheat under semi-arid Mediterranean conditions.
- Published
- 2020
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68. Comparing ambulatory care practices of primary care and traditional medicine residents.
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Bennett, S E, Goodson, J D, Izen, J E, Branch, W T, Clark, W C, Hatem, C J, Lawrence, R S, Delbanco, T L, and Goroll, A H
- Published
- 1985
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69. Multicenter evaluation of primary care internal medicine residency training. Are practice goals met?
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Goodson, J D, Bennett, S E, Izen, J E, Branch, W T, Clark, W D, Dubnoff, J S, Hatem, C J, Lawrence, R S, and Goroll, A H
- Published
- 1984
70. Expected increase in staple crop imports in water-scarce countries in 2050
- Author
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Hatem Chouchane, Maarten S. Krol, and Arjen Y. Hoekstra
- Subjects
Environmental technology. Sanitary engineering ,TD1-1066 - Abstract
Population growth paired with growing freshwater scarcity in various parts of the world will reduce the potential of food self-sufficiency in many countries. Today, two thirds of the global population are already living in areas facing severe water scarcity at least one month of the year. This raises the importance of addressing the relationship between water availability and food import in water-scarce countries. Net import of staple crops (including cereals, roots, and tubers) is analysed in relation to water availability per capita for the period 1961–2010, considering five decadal averages. The relation found is used, together with the population growth scenarios from the United Nations, to project staple crop imports in water-scarce countries for the year 2050. As a result of population growth in water-scarce countries alone, global international trade in staple crops is projected to increase by a factor of 1.4–1.8 towards 2050 (compared to the average in 2001–2010), in order to meet the staple food needs of the 42 most water-scarce countries in the world. Keywords: Global trade, Food security, Staple crops, Water-scarcity, Population growth
- Published
- 2018
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71. MIP diversity from Trichoderma: Structural considerations and transcriptional modulation during mycoparasitic association with Fusarium solani olive trees.
- Author
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Maroua Ben Amira, Robin Mom, David Lopez, Hatem Chaar, Ali Khouaja, Valérie Pujade-Renaud, Boris Fumanal, Aurélie Gousset-Dupont, Gisèle Bronner, Philippe Label, Jean-Louis Julien, Mohamed Ali Triki, Daniel Auguin, and Jean-Stéphane Venisse
- Subjects
Medicine ,Science - Abstract
Major intrinsic proteins (MIP) are characterized by a transmembrane pore-type architecture that facilitates transport across biomembranes of water and a variety of low molecular weight solutes. They are found in all parts of life, with remarkable protein diversity. Very little is known about MIP from fungi. And yet, it can legitimately be stated that MIP are pivotal molecular components in the privileged relationships fungi enjoy with plants or soil fauna in various environments. To date, MIP have never been studied in a mycoparasitism situation. In this study, the diversity, expression and functional prediction of MIP from the genus Trichoderma were investigated. Trichoderma spp. genomes have at least seven aquaporin genes. Based on a phylogenetic analysis of the translated sequences, members were assigned to the AQP, AQGP and XIP subfamilies. In in vitro and in planta assays with T. harzianum strain Ths97, expression analyses showed that four genes were constitutively expressed. In a mycoparasitic context with Fusarium solani, the causative agent of fusarium dieback on olive tree roots, these genes were up-regulated. This response is of particular interest in analyzing the MIP promoter cis-regulatory motifs, most of which are involved in various carbon and nitrogen metabolisms. Structural analyses provide new insights into the possible role of structural checkpoints by which these members transport water, H2O2, glycerol and, more generally, linear polyols across the membranes. Taken together, these results provide the first evidence that MIP may play a key role in Trichoderma mycoparasitism lifestyle.
- Published
- 2018
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72. Concentration-dependent diffusion of ion-implanted silicon in In0.53Ga0.47As.
- Author
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Aldridge Jr., H. L., Lind, A. G., Law, M. E., Hatem, C., and Jones, K. S.
- Subjects
ION implantation ,METAL organic chemical vapor deposition ,SECONDARY ion mass spectrometry ,GALLIUM arsenide ,SILICON ,DIFFUSION processes - Abstract
In contrast to prior reports, evidence of concentration-dependent diffusion is reported for Si implanted In
0.53 Ga0.47 As. The Fickian and concentration-dependent components of diffusivities were extracted using the Florida object oriented process and device simulator. The migration energy for silicon diffusion in In0.53 Ga0.47 As was calculated to be 2.4 and 1.5 eV for the Fickian and concentration dependent components of diffusion, respectively. A lack of change in diffusivities at given anneal temperatures suggest that transient-enhanced diffusion has not occurred. Due to these findings, silicon diffusion at high doping concentrations (>1 × 1020 cm-3 ) should be better characterized and understood for future complimentary metal-oxide semiconductor applications. [ABSTRACT FROM AUTHOR]- Published
- 2014
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73. Multiple mRNAs encode the avian lysosomal membrane protein LAMP-2, resulting in alternative transmembrane and cytoplasmic domains.
- Author
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Hatem, C L, Gough, N R, and Fambrough, D M
- Abstract
Lysosomal membranes are enriched in extensively glycosylated transmembrane proteins, LAMP-1 and LAMP-2. LAMP-1 proteins have been characterized from several mammalian species and from chickens, but no non-mammalian homologues of LAMP-2 have been described, and no splice variants of either protein have been reported. Here we report the characterization of three cDNA clones encoding chicken LAMP-2. The nucleotide sequences of the cDNAs diverge at their 3' ends within the open reading frame, resulting in sequences that code for three different transmembrane and cytoplasmic domains. Southern analysis suggests that a single gene encodes the common region of chicken LAMP-2. The position of the divergence and the identity of the common sequence are consistent with alternative splicing of 3' exons. Analysis of the mRNAs present in adult chicken tissues suggests tissue-specific expression of the three chicken LAMP-2 variants, with LAMP-2b expressed primarily in the brain. The cytoplasmic domain of LAMP-type proteins contains the targeting signal for directing these molecules to the lysosome. Using chimeras consisting of the lumenal domain of chicken LEP100 (a LAMP-1) and the transmembrane and cytoplasmic domains of the LAMP-2 variants, we demonstrate in transfected mouse L cells that all three LAMP-2 carboxyl-terminal regions are capable of targeting the chimeric proteins to lysosomes. Levels of expression, subcellular distribution, and glycosylation of the LAMP proteins have all been shown to change with differentiation in mammalian cells and to be correlated with metastatic potential in certain tumor cell lines. Alternative splicing of the LAMP-2 transcript may play a role in these changes.
- Published
- 1995
74. Unusual organization of the human T-cell receptor beta-chain gene complex is linked to recombination hotspots.
- Author
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Seboun, E, Houghton, L, Hatem, C J, Lincoln, R, and Hauser, S L
- Abstract
Two rare Sfi I polymorphisms of 360 kb and 280 kb present within the human T-cell antigen receptor beta-chain gene complex were revealed by pulsed-field gel electrophoresis. They represent allelic variants of the polymorphic 330- and 300-kb Sfi I fragments previously described. The 360-kb polymorphism results from duplication of the 30-kb DNA fragment responsible for the 330/300-kb insertion/deletion-related polymorphism. The 280-kb polymorphism results from a 20-kb deletion from the 300-kb SfiI allele. The rare polymorphisms also map on either side of a Sal I site located near a recombination hotspot, suggesting that germline duplications and deletions arose from nonhomologous crossover events.
- Published
- 1993
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75. Estimate of biomass and carbon pools in disturbed and undisturbed oak forests in Tunisia
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Lobna Zribi, Hatem Chaar, Abdelhamid Khaldi, Belgacem Henchi, Florent Mouillot, and Fatma Gharbi
- Subjects
Forestry ,SD1-669.5 - Abstract
Aim of the study. To estimate biomass and carbon accumulation in a young and disturbed forest (regenerated after a tornado) and an aged cork oak forest (undisturbed forest) as well as its distribution among the different pools (tree, litter and soil). Area of study. The north west of Tunisia Material and methods. Carbon stocks were evaluated in the above and belowground cork oak trees, the litter and the 150 cm of the soil. Tree biomass was estimated in both young and aged forests using allometric biomass equations developed for wood stem, cork stem, wood branch, cork branch, leaves, roots and total tree biomass based on combinations of diameter at breast height, total height and crown length as independent variables. Main results. Total tree biomass in forests was 240.58 Mg ha-1 in the young forest and 411.30 Mg ha-1 in the aged forest with a low root/shoot ratio (0.41 for young forest and 0.31 for aged forest). Total stored carbon was 419.46 Mg C ha-1 in the young forest and 658.09 Mg C ha-1 in the aged forest. Carbon stock (Mg C ha-1) was estimated to be113.61(27.08%) and 194.08 (29.49%) in trees, 3.55 (0.85%) and 5.73 (0.87%) in litter and 302.30 (72.07%) and 458.27 (69.64%) in soil in the young and aged forests, respectively. Research highlights. Aged undisturbed forest had the largest tree biomass but a lower potential for accumulation of carbon in the future; in contrast, young disturbed forest had both higher growth and carbon storage potential. Keywords: Tree biomass; disturbance; allometry; cork oak forests; soil organic carbon stock.
- Published
- 2016
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76. Understanding the femoral catheter.
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Deshpande K and Hatem C
- Published
- 2007
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77. Letters to future leaders...
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Ball K, Hatem C, and Sangermano C
- Published
- 2000
78. Fermi-Level Effects on Extended Defect Evolution in Si+and P+Implanted In0.53Ga0.47As
- Author
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Lind, A. G., Aldridge, H. L., Bomberger, C. C., Hatem, C., Zide, J. M. O., and Jones, K. S.
- Abstract
The evolution of implant damage in InGaAs is studied for electrically active Si+and isoelectronic P+implants. Extrinsic loops formed by excess interstitials are shown to be less stable upon annealing for n-type Si+implants relative to isoelectronic P+implants. Damage created by P+implants into heavily n-doped InGaAs is also shown to be less stable than damage created by P+implants into unintentionally doped InGaAs indicating that the background doping concentration can significantly effect the evolution of implant damage upon annealing. Previous results have suggested that the electrical activation and diffusion behavior of n-type dopants, like Si in InGaAs, may be strongly influenced by vacancy concentration. TEM results in this study also suggest that heavy n-type doping in InGaAs results in the formation of a large population of vacancy defects that enhance the dissolution or inhibit formation of interstitial loops.
- Published
- 2016
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79. Calculated Risk: A Provider's Guide to Assessing and Controlling the Financial Risk of Managed Care
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Hatem, C.
- Published
- 1996
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80. Treatment of adenosine deaminase deficiency with polyethylene glycol-modified adenosine deaminase.
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Hershfield, M S, Buckley, R H, Greenberg, M L, Melton, A L, Schiff, R, Hatem, C, Kurtzberg, J, Markert, M L, Kobayashi, R H, and Kobayashi, A L
- Subjects
- *
RESEARCH , *RESEARCH methodology , *EVALUATION research , *MEDICAL cooperation , *IMMUNOLOGICAL deficiency syndromes , *HYDROLASES , *INTRAMUSCULAR injections , *COMPARATIVE studies , *POLYETHYLENE glycol , *BONE marrow , *ERYTHROCYTES - Abstract
We treated two children who had adenosine deaminase deficiency and severe combined immunodeficiency disease by injecting bovine adenosine deaminase modified by conjugation with polyethylene glycol. The modified enzyme was rapidly absorbed after intramuscular injection and had a half-life in plasma of 48 to 72 hours. Weekly doses of approximately 15 U per kilogram of body weight maintained plasma adenosine deaminase activity at two to three times the level of erythrocyte adenosine deaminase activity in normal subjects. The principal biochemical consequences of adenosine deaminase deficiency were almost completely reversed. In erythrocytes, adenosine nucleotides increased and deoxyadenosine nucleotides decreased to less than 0.5 percent of total adenine nucleotides. The activity of S-adenosylhomocysteine hydrolase, which is inactivated by deoxyadenosine, increased to normal in red cells and nucleated marrow cells. Neither toxic effects nor hypersensitivity reactions were observed. In vitro tests of the cellular immune function of each patient showed marked improvement, along with an increase in circulating T lymphocytes. Clinical improvement was indicated by absence of infection and resumption of weight gain. We conclude that from the standpoints of efficacy, convenience, and safety, polyethylene glycol-modified adenosine deaminase is preferable to red-cell transfusion as a treatment for adenosine deaminase deficiency. Patients with other inherited metabolic diseases in which accumulated metabolites equilibrate with plasma could benefit from treatment with the appropriate polyethylene glycol-modified enzyme. [ABSTRACT FROM AUTHOR]
- Published
- 1987
81. Effectiveness of medical nutrition therapy in the management of adult dyslipidemia: A systematic review and meta-analysis.
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Mohr AE, Hatem C, Sikand G, Rozga M, Moloney L, Sullivan J, De Waal D, and Handu D
- Subjects
- Adult, Humans, Cholesterol, LDL, Cholesterol, HDL, Triglycerides, Dyslipidemias therapy, Cardiovascular Diseases, Nutrition Therapy
- Abstract
Cardiovascular disease (CVD) is a leading cause of mortality in the United States. Many primary risk factors, such as dyslipidemia and blood pressure, are modifiable with diet and lifestyle interventions. Therefore, the objective of this systematic review and meta-analysis was to evaluate the effectiveness of medical nutrition therapy (MNT) interventions provided by registered dietitian nutritionists (RDN) or international equivalents, compared to usual care or no MNT, on lipid profile and blood pressure (secondary outcome) in adults with dyslipidemia. The databases MEDLINE, CINAHL, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews were searched for randomized controlled trials (RCTs) published between January 2005 and July 2021. Meta-analyses were performed using a random-effects model for lipid outcomes (seven RCTs, n=838), systolic blood pressure (SBP) (three RCTs, n=308), and diastolic blood pressure (DBP) (two RCTs, n=109). Compared to usual care or no intervention, MNT provided by RDNs improved total cholesterol (total-C) [mean difference (95% CI): -20.84 mg/dL (-40.60, -1.07), P=0.04]; low-density lipoprotein cholesterol (LDL-C) [-11.56 mg/dL (-21.10, -2.03), P=0.02]; triglycerides (TG) [-32.55 mg/dL (-57.78, -7.32), P=0.01];; and SBP [ -8.76 mm Hg (-14.06 lower to -3.45) P<0.01].High-density lipoprotein cholesterol (HDL-C) [1.75 mg/dl (-1.43, 4.92), P=0.28] and DBP [-2.9 mm Hg (-7.89 to 2.09), P=0.25] were unchanged. Certainty of evidence was moderate for total-C, LDL-C, and TG, and low for HDL-C, SBP, and DBP. In conclusion, in adults with dyslipidemia, MNT interventions provided by RDNs are effective for improving serum lipids/lipoproteins and SBP levels., Competing Interests: Declaration of Competing Interest Authors have no conflicts of interest to disclose., (Copyright © 2022. Published by Elsevier Inc.)
- Published
- 2022
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82. The Importance of Health Values Among Health Care Providers.
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Cepni AB, Hatem C, Ledoux TA, and Johnston CA
- Abstract
Medical professionals' healthy eating and physical activity behaviors are likely to wane as other life events and everyday pressures increase. This is vital because as health behaviors decrease, the likelihood that this topic is addressed with patients also decreases. Increased training to improve health care providers' knowledge about lifestyle behaviors may be inadequate to actually bring about a healthier lifestyle. The area of personal identity and value formation may shed light on a significant barrier in this area. Developing health care professionals who have values consistent with a healthy diet and physical activity, instead of just being informed about it, would increase the likelihood that healthy behavior changes are discussed with patients. Strategies to encourage value formation around healthy lifestyles among medical professionals are discussed., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© 2021 The Author(s).)
- Published
- 2021
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83. Food insecurity and housing instability during early childhood as predictors of adolescent mental health.
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Hatem C, Lee CY, Zhao X, Reesor-Oyer L, Lopez T, and Hernandez DC
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- Adolescent, Adult, Child, Child, Preschool, Female, Food Insecurity, Housing, Humans, Longitudinal Studies, Male, Anxiety psychology, Child of Impaired Parents psychology, Depression psychology, Mothers psychology, Parenting psychology, Poverty psychology
- Abstract
This study examined the effects of food insecurity and housing instability experiences during early childhood on adolescent anxiety and depressive symptoms through maternal depression and parenting stress. This longitudinal study included 4 waves of data from the Fragile Families and Child Well-Being Study ( n = 2,626). Food insecurity was measured when the child was 5 years of age using the U.S. Department of Agriculture's 18-item Food Security Scale. Housing instability was also measured when the child was 5 years of age based on an affirmative response to 6 housing adversity items. Maternal depression and parenting stress were measured when the child was 9 years of age. Anxiety and depressive symptoms were assessed when the child (now adolescent) was 15 years of age using 6 items of the Brief Symptom Inventory 18 anxiety subscale and 5 items of the Centers for Epidemiologic Studies Depression Scale, respectively. Two structural equation models assessed the associations between food insecurity and housing instability on adolescent anxiety (Model 1) and depressive symptoms (Model 2) through maternal depression and parenting stress simultaneously, controlling for sociodemographic characteristics. Results suggest that experiencing both food insecurity and housing instability during early childhood increases the risk of long-term adolescent depressive (indirect: B = 0.008, 95% CI [0.002, 0.016]) and anxiety (indirect: B = 0.012, 95% CI [0.002, 0.026]) symptoms through maternal depression to parenting stress. Screening for food insecurity and housing instability during early childhood could potentially identify both mothers who are at risk for depression and parenting stress and children who are at increased risk for anxiety or depressive symptoms during adolescence. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
- Published
- 2020
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84. Wet-chemical etching of FIB lift-out TEM lamellae for damage-free analysis of 3-D nanostructures.
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Turner EM, Sapkota KR, Hatem C, Lu P, Wang GT, and Jones KS
- Abstract
Reducing ion beam damage from the focused ion beam (FIB) during fabrication of cross sections is a well-known challenge for materials characterization, especially cross sectional characterization of nanostructures. To address this, a new method has been developed for cross section fabrication enabling high resolution transmission electron microscopy (TEM) analysis of 3-D nanostructures free of surrounding material and free of damage detectable by TEM analysis. Before FIB processing, nanopillars are encapsulated in a sacrificial oxide which acts as a protective layer during FIB milling. The cross sectional TEM lamella containing the nanopillars is then mounted and thinned with some modifications to conventional FIB sample preparation that provide stability for the lamella during the following wet-chemical dip etch. The wet-chemical etch of the TEM lamella removes the sacrificial oxide layer, freeing the nanopillars from any material that would obscure TEM imaging. Both high resolution TEM and aberration corrected scanning TEM images of Si/SiGe pillars with diameters down to 30 nm demonstrate the successful application of this approach., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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85. Phosphorus monolayer doping (MLD) of silicon on insulator (SOI) substrates.
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Kennedy N, Duffy R, Eaton L, O'Connell D, Monaghan S, Garvey S, Connolly J, Hatem C, Holmes JD, and Long B
- Abstract
This paper details the application of phosphorus monolayer doping of silicon on insulator substrates. There have been no previous publications dedicated to the topic of MLD on SOI, which allows for the impact of reduced substrate dimensions to be probed. The doping was done through functionalization of the substrates with chemically bound allyldiphenylphosphine dopant molecules. Following functionalization, the samples were capped and annealed to enable the diffusion of dopant atoms into the substrate and their activation. Electrical and material characterisation was carried out to determine the impact of MLD on surface quality and activation results produced by the process. MLD has proven to be highly applicable to SOI substrates producing doping levels in excess of 1 × 10
19 cm-3 with minimal impact on surface quality. Hall effect data proved that reducing SOI dimensions from 66 to 13 nm lead to an increase in carrier concentration values due to the reduced volume available to the dopant for diffusion. Dopant trapping was found at both Si-SiO2 interfaces and will be problematic when attempting to reach doping levels achieved by rival techniques.- Published
- 2018
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86. Development of primary early-onset colorectal cancers due to biallelic mutations of the FANCD1/BRCA2 gene.
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Degrolard-Courcet E, Sokolowska J, Padeano MM, Guiu S, Bronner M, Chery C, Coron F, Lepage C, Chapusot C, Loustalot C, Jouve JL, Hatem C, Ferrant E, Martin L, Coutant C, Baurand A, Couillault G, Delignette A, El Chehadeh S, Lizard S, Arnould L, Fumoleau P, Callier P, Mugneret F, Philippe C, Frebourg T, Jonveaux P, and Faivre L
- Subjects
- Adult, Amino Acid Substitution, Chromosome Breakage, Colorectal Neoplasms diagnosis, Computational Biology, DNA Mutational Analysis, Female, Humans, Pedigree, RNA Splice Sites, RNA Splicing, Age of Onset, Alleles, BRCA2 Protein genetics, Colorectal Neoplasms genetics, Mutation
- Abstract
Fanconi anaemia (FA) is characterized by progressive bone marrow failure, congenital anomalies, and predisposition to malignancy. In a minority of cases, FA results from biallelic FANCD1/BRCA2 mutations that are associated with early-onset leukaemia and solid tumours. Here, we describe the clinical and molecular features of a remarkable family presenting with multiple primary colorectal cancers (CRCs) without detectable mutations in genes involved in the Mendelian predisposition to CRCs. We unexpectedly identified, despite the absence of clinical cardinal features of FA, a biallelic mutation of the FANCD1/BRCA2 corresponding to a frameshift alteration (c.1845_1846delCT, p.Asn615Lysfs*6) and a missense mutation (c.7802A>G, p.Tyr2601Cys). The diagnosis of FA was confirmed by the chromosomal analysis of lymphocytes. Reverse transcriptase (RT)-PCR analysis revealed that the c.7802A>G BRCA2 variation was in fact a splicing mutation that creates an aberrant splicing donor site and results partly into an aberrant transcript encoding a truncated protein (p.Tyr2601Trpfs*46). The atypical FA phenotype observed within this family was probably explained by the residual amount of BRCA2 with the point mutation c.7802A>G in the patients harbouring the biallelic FANCD1/BRCA2 mutations. Although this report is based in a single family, it suggests that CRCs may be part of the tumour spectrum associated with FANCD1/BRCA2 biallelic mutations and that the presence of such mutations should be considered in families with CRCs, even in the absence of cardinal features of FA.
- Published
- 2014
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87. In vivo organization of the FtsZ-ring by ZapA and ZapB revealed by quantitative super-resolution microscopy.
- Author
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Buss J, Coltharp C, Huang T, Pohlmeyer C, Wang SC, Hatem C, and Xiao J
- Subjects
- Carrier Proteins genetics, Cell Cycle Proteins genetics, Escherichia coli genetics, Escherichia coli Proteins genetics, Gene Deletion, Bacterial Proteins metabolism, Carrier Proteins metabolism, Cell Cycle Proteins metabolism, Cytoskeletal Proteins metabolism, Escherichia coli metabolism, Escherichia coli Proteins metabolism, Macromolecular Substances metabolism, Microscopy methods, Protein Multimerization
- Abstract
In most bacterial cells, cell division is dependent on the polymerization of the FtsZ protein to form a ring-like structure (Z-ring) at the midcell. Despite its essential role, the molecular architecture of the Z-ring remains elusive. In this work we examine the roles of two FtsZ-associated proteins, ZapA and ZapB, in the assembly dynamics and structure of the Z-ring in Escherichia coli cells. In cells deleted of zapA or zapB, we observed abnormal septa and highly dynamic FtsZ structures. While details of these FtsZ structures are difficult to discern under conventional fluorescence microscopy, single-molecule-based super-resolution imaging method Photoactivated Localization Microscopy (PALM) reveals that these FtsZ structures arise from disordered arrangements of FtsZ clusters. Quantitative analysis finds these clusters are larger and comprise more molecules than a single FtsZ protofilament, and likely represent a distinct polymeric species that is inherent to the assembly pathway of the Z-ring. Furthermore, we find these clusters are not due to the loss of ZapB-MatP interaction in ΔzapA and ΔzapB cells. Our results suggest that the main function of ZapA and ZapB in vivo may not be to promote the association of individual protofilaments but to align FtsZ clusters that consist of multiple FtsZ protofilaments., (© 2013 John Wiley & Sons Ltd.)
- Published
- 2013
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88. Stochastic expression dynamics of a transcription factor revealed by single-molecule noise analysis.
- Author
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Hensel Z, Feng H, Han B, Hatem C, Wang J, and Xiao J
- Subjects
- Bacteriophage lambda genetics, Bacteriophage lambda metabolism, Escherichia coli K12 virology, Gene Expression, Genes, Viral, Homeostasis, Models, Biological, Protein Biosynthesis, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Stochastic Processes, Repressor Proteins genetics, Repressor Proteins metabolism, Transcription Factors genetics, Transcription Factors metabolism, Viral Regulatory and Accessory Proteins genetics, Viral Regulatory and Accessory Proteins metabolism
- Abstract
Gene expression is inherently stochastic; precise gene regulation by transcription factors is important for cell-fate determination. Many transcription factors regulate their own expression, suggesting that autoregulation counters intrinsic stochasticity in gene expression. Using a new strategy, cotranslational activation by cleavage (CoTrAC), we probed the stochastic expression dynamics of cI, which encodes the bacteriophage λ repressor CI, a fate-determining transcription factor. CI concentration fluctuations influence both lysogenic stability and induction of bacteriophage λ. We found that the intrinsic stochasticity in cI expression was largely determined by CI expression level irrespective of autoregulation. Furthermore, extrinsic, cell-to-cell variation was primarily responsible for CI concentration fluctuations, and negative autoregulation minimized CI concentration heterogeneity by counteracting extrinsic noise and introducing memory. This quantitative study of transcription factor expression dynamics sheds light on the mechanisms cells use to control noise in gene regulatory networks.
- Published
- 2012
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89. Epidemiology and management of liver metastases from colorectal cancer.
- Author
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Manfredi S, Lepage C, Hatem C, Coatmeur O, Faivre J, and Bouvier AM
- Subjects
- Age Factors, Aged, Chemotherapy, Adjuvant statistics & numerical data, Female, France epidemiology, Hepatectomy statistics & numerical data, Humans, Incidence, Liver Neoplasms epidemiology, Male, Middle Aged, Neoplasm Recurrence, Local epidemiology, Neoplasm Staging, Palliative Care statistics & numerical data, Population Surveillance, Prognosis, Registries, Sex Factors, Survival Rate, Treatment Outcome, Colonic Neoplasms epidemiology, Liver Neoplasms secondary, Rectal Neoplasms epidemiology
- Abstract
Objective/background: Little is known about the epidemiology and the management of liver metastases from colorectal cancer at a population level. The aim of this population-based study was to report on the incidence, treatment, and prognosis of synchronous and metachronous liver metastases., Methods: Data were obtained from the population-based cancer registry of Burgundy (France)., Results: The proportion of patients with synchronous liver metastases was 14.5%. Age-standardized incidence rates were 7.6 per 100,000 in males, 3.7 per 100,000 in females. The 5-year cumulative metachronous liver metastasis rate was 14.5%. It was 3.7% for TNM stage I tumors, 13.3% for stage II, and 30.4% for stage III (P < 0.001). The risk of liver metastasis was also associated to gross features. Resection for cure was performed in 6.3% of synchronous liver metastases and 16.9% of metachronous liver metastases. Age, presence of another site of recurrence, and period of diagnosis were independent factors associated with the performance of a resection for cure. The 1- and 5-year survival rates were 34.8% and 3.3% for synchronous liver metastases. Their corresponding rates were, respectively, 37.6% and 6.1% for metachronous liver metastases., Conclusion: Liver metastases from colorectal cancer remain a substantial problem. More effective treatments and mass screening represent promising approaches to decrease this problem.
- Published
- 2006
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90. Management of hepatitis C patients: a French population-based study.
- Author
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Hatem C, Minello A, Martin L, Jooste V, Beurton I, Milan C, Bonithon-Kopp C, Bresson-Hadni S, Miguet JP, and Hillon P
- Subjects
- Adolescent, Adult, Aged, Female, France, Humans, Male, Middle Aged, Hepatitis C diagnosis, Hepatitis C drug therapy
- Abstract
Aims: Our aim was to assess the proportion of patients in a well-defined population reaching specialized medical care after hepatitis C diagnosis., Methods: Hepatitis C-positive patients recorded in the population-based registry of Cote-d'Or, an administrative district in France, constituted the study population., Results: Between 1994 and 1999, new hepatitis C-positive serology was diagnosed in 847 patients, of whom 690 were eligible for this study. A total of 135 patients had not been given specialized medical care after diagnosis; among them, 50.4% had a normal serum alanine transferase level at diagnosis, 62.2% had risk factors related to lifestyle (drug addiction, sexual risk...), and 26.7% were current alcoholics. The 555 other patients were involved in specialized medical care after diagnosis: 42.7% had a liver biopsy and 27.0% were treated. Treatment was carried out more often in males than in females (OR: 1.67; P<0.005), and in patients less than 65 years old (OR: 2.94; P<0.0002). Nearly 30.5% of patients with a Metavir score greater than A1F1 did not undergo treatment., Conclusion: This study shows that in a general population at least one patient out of five with hepatitis C infection remains outside the health care system. It also reveals that management practices vary with gender. Further surveys are needed to better understand this phenomenon.
- Published
- 2004
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91. [Is chronic hepatitis C treatment as efficient in the general population as in randomised trials?].
- Author
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Hatem C, Jooste V, Minello A, Evrard P, Obert B, Bresson Hadni S, Miguet JP, Faivre J, Bonithon C, and Hillon P
- Subjects
- Adolescent, Adult, Aged, Antiviral Agents therapeutic use, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Middle Aged, Randomized Controlled Trials as Topic, Hepatitis C, Chronic drug therapy
- Abstract
Aims: The aim of this population-based study was to determine the effectiveness of antiviral therapy in non selected chronic hepatitis C patients., Methods: The study was performed in all new patients with anti-HCV antibodies who had registered in a specialised viral hepatitis registry since 1994 and who lived in the French departments of Côte-d'Or and Doubs (1 005 817 inhabitants)., Results: 1251 of the 1508 recorded cases were studied; 262 were treated. Results of treatment were available in 238 cases, 157 were treated with interferon alone and 81 with interferon + ribavirine. Sustained virological response was observed in 18% of cases after interferon alone and 46.9% after interferon + ribavirine. In multivariate analysis, age under 40 and combined therapy were positively correlated to sustained virological response. Premature treatment discontinuation was associated with a lack of sustained response which was unrelated to gender or liver fibrosis. Fifty seven patients received combined therapy after unsuccessful monotherapy: sustained virological response rates were 33.3% in responders-relapsers and 23.7% in non-responders to initial therapy., Conclusions: This study showed that sustained response rates were similar in non selected patients from the general population and in highly selected patients from randomised trials. These results emphasize the necessity of increasing the ratio of treated patients which is still too low in general population.
- Published
- 2003
92. Biased expression of T cell receptor genes characterizes activated T cells in multiple sclerosis cerebrospinal fluid.
- Author
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Usuku K, Joshi N, Hatem CJ Jr, Wong MA, Stein MC, and Hauser SL
- Subjects
- Adult, Cell Division physiology, Cells, Cultured, HLA-DR Antigens genetics, Humans, Leukocytes, Mononuclear immunology, Middle Aged, Multigene Family, Multiple Sclerosis cerebrospinal fluid, Polymerase Chain Reaction, Gene Expression Regulation physiology, Lymphocyte Activation, Multiple Sclerosis immunology, Receptors, Antigen, T-Cell genetics
- Abstract
To better characterize the inflammatory response that occurs in the nervous system in multiple sclerosis (MS), T-cell receptor (TCR) gene expression was quantified from cerebrospinal fluid (CSF) cells of 21 patients with active disease. Unstimulated CSF cells expressed each of 22 different TCR beta chain variable region (V beta) gene families in proportion to their expression in simultaneously sampled peripheral blood. When CSF cells from individuals with MS were expanded by in vitro culture in T-cell growth factor/interleukin 2 and 4-containing medium (TCGF/IL2/IL4), restricted numbers of V beta genes were expressed. In many subjects, expanded CSF cells expressed predominantly V beta 2. In contrast to CSF, expansion of corresponding peripheral blood mononuclear cells (PBMC) in TCGF/IL2/IL4 resulted in persistent expression of all V beta gene families. Within individuals, different V beta genes were overexpressed by PBMC compared with CSF cells. No effect of the HLA haplotype of the individual on CSF V beta gene expression was observed. Expanded CSF cells retained their capacity to respond to mitogen stimulation, but the proliferative response to myelin basic protein (MBP) was not enhanced. Finally, freshly obtained CSF cells stimulated directly with MBP also expressed a limited number of V beta genes, although these were generally different from patterns observed following stimulation with TCGF/IL2/IL4. Thus, restricted populations of T cells capable of responding to TCGF/IL2/IL4, presumably reflecting in vivo activated cells, are compartmentalized in the nervous system in MS.
- Published
- 1996
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93. The family of LAMP-2 proteins arises by alternative splicing from a single gene: characterization of the avian LAMP-2 gene and identification of mammalian homologs of LAMP-2b and LAMP-2c.
- Author
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Gough NR, Hatem CL, and Fambrough DM
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Evolution, Molecular, Gene Expression Regulation, Lysosomal Membrane Proteins, Lysosomes metabolism, Mice genetics, Molecular Sequence Data, Sequence Alignment, Sequence Homology, Amino Acid, Species Specificity, Antigens, CD genetics, Chickens genetics, Genes, Membrane Glycoproteins genetics, RNA Splicing
- Abstract
The two lysosome-associated membrane proteins, LAMP-1 and LAMP-2, are major integral membrane proteins of the lysosomes. They also occur in the plasma membrane, where they have been discovered independently as principal lactosaminoglycan-bearing glycoproteins and as tumor antigens. Avian LAMP-2 has recently been shown to be encoded by at least three transcripts resulting in variant transmembrane and cytoplasmic domains (Hatem et al., 1995). We report isolation and characterization of chicken genomic clones indicating that the three transcripts are the result of alternative splicing of a single LAMP-2 gene. Only a single LAMP-2, homologous to chicken LAMP-2a, has been described in mammals. To ascertain whether multiple forms of LAMP-2 also occur in mammals, we cloned cDNAs encoding LAMP-2 variants homologous to avian LAMP-2b and LAMP-2c from mouse brain cDNA libraries. Thus, the family of LAMP-2 proteins is conserved from bird to mammals and the diversity is generated by alternative splicing of a single LAMP-2 gene.
- Published
- 1995
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94. The human T-cell receptor beta-chain repertoire: longitudinal fluctuations and assessment in MHC matched populations.
- Author
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Usuku K, Joshi N, Hatem CJ Jr, Alper CA, Schoenfeld DA, and Hauser SL
- Subjects
- Base Sequence, CD4 Antigens, CD4-Positive T-Lymphocytes immunology, CD8 Antigens, DNA, Single-Stranded, Gene Expression, Humans, Molecular Sequence Data, Polymerase Chain Reaction, RNA, Messenger metabolism, Sensitivity and Specificity, Genetic Variation, Major Histocompatibility Complex genetics, Receptors, Antigen, T-Cell, alpha-beta genetics, T-Lymphocyte Subsets immunology
- Abstract
The influence of the environment and of the major histocompatibility complex (MHC) in shaping the human T-cell receptor beta-chain variable region (TCRBV) repertoire has not been systematically studied. Here, expression of TCRBV gene families was estimated by a sensitive polymerase chain reaction (PCR)-based method. Serial studies of peripheral blood, performed at 2-week intervals over a 3-month period, revealed that fluctuation in the expression of many TCRBV genes occurred in healthy individuals and in the absence of clinically evident infections. Fluctuation of TCRBV4, TCRBV5.2, TCRBV9, and TCRBV13.1 genes were present in all subjects. Additional TCRBV genes fluctuated in some but not in other individuals. Comparison of the TCRBV repertoire between these unrelated individuals indicated differences in the mean expression of TCRBV5.1, TCRBV9, TCRBV11, TCRBV15, TCRBV17, and TCRBV20 genes. For any TCRBV gene, intersubject differences were generally of a magnitude of twofold or less. Larger differences characterized the TCRBV repertoire of CD4 compared to CD8 cells. Some differences, for example over-representation of TCRBV2 and TCRBV5.1 on CD4, and TCRBV10, TCRBV14, and TCRBV16 on CD8 cells, were present in most subjects. Individuals homozygous for DR2- or DR3-bearing extended MHC haplotypes displayed similar individual variability of TCRBV expression. These data indicate that the circulating TCRBV repertoire in humans is both dynamic and diverse. Both environment and MHC effects contribute to the diversity of TCRBV expression.
- Published
- 1993
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95. Ca(2+)-regulated serine protease associated with the nuclear scaffold.
- Author
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Clawson GA, Norbeck LL, Hatem CL, Rhodes C, Amiri P, McKerrow JH, Patierno SR, and Fiskum G
- Subjects
- Amino Acid Sequence, Animals, Calmodulin physiology, Cricetinae, Fibroblasts drug effects, Intermediate Filaments metabolism, Lamins, Liver enzymology, Liver Neoplasms, Experimental pathology, Male, Mesocricetus metabolism, Mice, Mice, Inbred C3H, Molecular Sequence Data, Molecular Weight, Nuclear Proteins metabolism, Peptides pharmacology, Rats, Rats, Sprague-Dawley metabolism, Sequence Homology, Amino Acid, Sequence Homology, Nucleic Acid, Serine Endopeptidases immunology, Serine Endopeptidases physiology, Species Specificity, Substrate Specificity, Tumor Cells, Cultured, Calcium physiology, Nuclear Matrix enzymology, Serine Endopeptidases isolation & purification
- Abstract
The nuclear scaffold (NS) is a proteinaceous network of orthogonally arrayed intermediate filament proteins, termed lamins, which is responsible for nuclear structure. Recent work has demonstrated that a subset of lamins A/C is proteolytically cleaved to produce an ATP-binding protein. This proteolytic cleavage is accomplished by a NS protease activity, which shows a considerable selectivity for lamins A/C and is stringently regulated by Ca2+ in vitro, suggesting that it might also participate in control of NS breakdown in various scenarios. Here, we identify the major NS protease as a novel serine protease with a predominantly chymotryptic-like substrate preference, and we show that even transient perturbations in cytosolic Ca2+ have significant effects on the NS protease activity. This NS protease activity shows extensive similarities to the multicatalytic proteinase complex. In addition to a potential role in control of NS breakdown at mitosis and/or under pathological conditions, this NS protease is also strategically located for other functions, such as inactivation of various oncogenic proteins or maturation-promoting factor.
- Published
- 1992
96. Interaction of human immunodeficiency virus type I Rev protein with nuclear scaffold nucleoside triphosphatase activity.
- Author
-
Clawson GA, Song YL, Schwartz AM, Shukla RR, Patel SG, Connor L, Blankenship L, Hatem C, and Kumar A
- Subjects
- Animals, Biological Transport, Cell Line, Genes, env, Lamins, Mice, Nuclear Proteins metabolism, Nucleoside-Triphosphatase, Phosphoric Monoester Hydrolases metabolism, RNA, Viral metabolism, Recombinant Fusion Proteins metabolism, Regulatory Sequences, Nucleic Acid, rev Gene Products, Human Immunodeficiency Virus, Gene Products, rev metabolism, HIV-1 metabolism, Lamin Type A, Nuclear Matrix metabolism, Phosphoric Monoester Hydrolases antagonists & inhibitors, RNA Processing, Post-Transcriptional
- Abstract
Human immunodeficiency virus type I encodes a regulatory protein, termed Rev, which is associated with the appearance of unspliced and partially spliced viral RNAs in the cytoplasm. Rev is believed to function via interaction with a sequence element in the env region of the viral RNA, termed the Rev-responsive element (RRE). In this study, we use a stably transfected, Rev-producing mouse cell line to show that low, functional levels of Rev are associated with the nuclear scaffold (NS). Immunohistochemical studies localize Rev to the NS. Furthermore, immunoblot analyses demonstrate the presence of Rev in NS preparations isolated from Rev-producing cells and document binding of purified Rev protein to isolated NS or to cloned lamin C in vitro. Results with an in vitro RNA transport assay suggest that Rev is associated with a significant defect in transport of RNAs which lack RRE, whereas transport of RRE-containing transcripts proceeds efficiently. This Rev-induced transport defect appears to be mediated via direct inhibition of NS nucleoside triphosphatase, an enzyme thought to be involved in the nucleocytoplasmic transport process. NS preparations isolated from Rev-producing cells show a significantly lower nucleoside triphosphatase activity than those from control preparations. Addition of Rev protein to isolated NS produces a significant inhibition of NS nucleoside triphosphatase activity, which is specifically reversed by addition of RRE transcripts. These data suggest that a major aspect of Rev function may involve selective modulation of host cell nucleocytoplasmic transport mechanisms via interaction with the NS.
- Published
- 1991
97. Alterations in nuclear scaffold constituents during carbon tetrachloride-induced liver regeneration.
- Author
-
Clawson GA, Madsen KR, Blankenship LJ, and Hatem CL
- Subjects
- Animals, Biological Transport, Male, Nucleoside-Triphosphatase, Rats, Rats, Inbred Strains, Carbon Tetrachloride pharmacology, Liver Regeneration drug effects, Phosphoric Monoester Hydrolases metabolism, RNA metabolism
- Abstract
Liver regeneration was induced in rats by treatment with CCl4, which results in substantial regenerative activity with a sharp mitotic response 2 days after intoxication. Closely paralleling the mitotic index, we observed fourfold increases in nuclear scaffold nucleoside triphosphatase, an activity thought to participate in nucleocytoplasmic RNA transport and in the 46 kD putative enzyme and its selective photolabeling. Because previous work has indicated that the 46 kD protein may be proteolytically derived from lamins A/C by cleavage at a tyrosine residue at aa376, we investigated the response of lamin A/C transcripts during this regeneration. Surprisingly, Northern blot analyses after CCl4 administration showed low levels of lamin A/C transcripts (which appeared to be predominantly poly[A]-), and we found a decrease in immunoprecipitable lamins A/C from in vitro translation of poly(A)- selected RNA. To circumvent potential problems with such analyses, we used reverse transcription/polymerase chain reaction amplification of lamin A/C transcripts from total cytoplasmic RNA. These assays showed a transient, comparatively minor increase in lamin A/C transcripts 1 day after treatment, but levels rapidly declined from 1 to 3 days and were decreased at 3 to 5 days. However, nuclear scaffold protease activity, which shows a considerable selectivity for lamins A/C and may be involved in derivation of the 46 kD protein, increased in parallel to the mitotic response and increases in nucleoside triphosphatase, as assessed using a nonspecific (Azocoll) protease assay. Assays with a specific tyrosine-containing substrate (Z-Y-Sbenzyl) showed an increase that mirrored that observed with the nonspecific substrate.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1991
98. Demethylation of ribosomal RNA by hepatocyte microsomal preparations.
- Author
-
Choe WT, Hatem CL, and Clawson GA
- Subjects
- Animals, Carbon Monoxide pharmacology, Catalysis, Male, Methylation, Microsomes, Liver drug effects, NADP metabolism, RNA, Ribosomal drug effects, Rats, Rats, Inbred Strains, Microsomes, Liver metabolism, RNA, Ribosomal metabolism
- Abstract
Previous work has shown that hypomethylation of rRNA is an important control for protein synthesis in rat hepatocytes, and that the net hypomethylation appears to arise from cytoplasmic events. Here we show that demethylation of rRNA is catalyzed by microsomal preparations. The rRNA demethylation is dependent upon NADPH and is almost completely inhibited by carbon monoxide. Demethylation appears to increase following galactosamine intoxication, a hepatotoxin which induces hypomethylation of rRNA and inhibition of protein synthesis.
- Published
- 1991
- Full Text
- View/download PDF
99. The Mr 46,000 nuclear scaffold ATP-binding protein: identification of the putative nucleoside triphosphatase by proteolysis and monoclonal antibodies directed against lamins A/C.
- Author
-
Clawson GA, Wang YF, Schwartz AM, and Hatem CL
- Subjects
- Amino Acid Sequence, Animals, Blotting, Western, Endopeptidases pharmacology, Lamin Type A, Lamins, Molecular Sequence Data, Molecular Weight, Nuclear Proteins immunology, Nucleoside-Triphosphatase, Peptide Fragments chemistry, Phosphoric Monoester Hydrolases immunology, Photochemistry, Rats, Recombinant Proteins immunology, Adenosine Triphosphate metabolism, Antibodies, Monoclonal immunology, Carrier Proteins metabolism, Nuclear Matrix metabolism, Nuclear Proteins metabolism, Phosphoric Monoester Hydrolases metabolism
- Abstract
Previous work suggested that the major Mr 46,000 ATP-binding protein [a putative nucleoside triphosphatase (NTPase)] found in rat liver nuclear scaffold (NS) may be proteolytically derived from lamins A/C. To definitively establish this identification, we undertook a series of photolabeling, proteolysis, and immunoprecipitation experiments. Mice were immunized with human lamin C expressed in bacteria, and monoclonal antibody-producing hybridomas were obtained. The purified monoclonal antibodies all recognized lamins A and C on immunoblots of NS, as well as Mr 46,000 or 34,000 proteolytic fragments as minor components. The Mr 46,000 photolabeled band was the only major NS component photolabeled with low concentrations of azido-ATP, and it was immunoprecipitated with anti-lamin monoclonal antibodies. To preclude the possibility that the photolabeled Mr 46,000 protein represented a minor component which comigrated with the Mr 46,000 lamin fragment and which specifically associated with lamins A/C during immunoprecipitation, a series of proteolytic digestions were undertaken. Digestion of the photolabeled Mr 46,000 peptide with chymotrypsin and staphylococcal protease V8 produced a limited number of photolabeled fragments, all of which comigrated with major stainable fragments produced from the Mr 46,000 lamin fragment. Cyanogen bromide cleavage of the photolabeled Mr 46,000 polypeptide, followed by polyacrylamide gel electrophoresis or high performance liquid chromatography/amino acid analyses, defined the COOH-terminal cleavage site as the Y residue at amino acid 376 and localized the photolabeled site to the COOH-terminal region (amino acids 372-376). In support of this proposed proteolytic cleavage site, specific assays with tyrosine-containing thiobenzyl ester substrate documented the presence of NS protease activity which cleaves at tyrosine residues; this activity shows a Km of 0.2 mM and a Kcat of approximately 250/s. Parallel experiments with mildly proteolyzed cloned lamin C preparations showed selective photolabeling of an Mr 34,000 fragment, which corresponds to a proteolytic breakdown product of the Mr 46,000 NS polypeptide; this Mr 34,000 photolabeled fragment was also immunoprecipitated with anti-lamin monoclonal antibodies and contained the same photolabeled site as the Mr 46,000 peptide. Cloned lamin C preparations were inactive in NTPase assays but did exhibit substantial ATP binding with an apparent KD = 4 x 10(-5) M ATP. These results indicate that the major Mr 46,000 photoaffinity-labeled protein in NS, which represents the putative NTPase thought to participate in nucleocytoplasmic transport, is derived from lamin A or lamin C by NS proteolytic activity which exposes a cryptic ATP-binding site near the highly conserved end of coil-2.(ABSTRACT TRUNCATED AT 400 WORDS)
- Published
- 1990
100. Evaluating the interview in primary care medicine.
- Author
-
Barsky AJ, Kazis LE, Freiden RB, Goroll AH, Hatem CJ, and Lawrence RS
- Subjects
- Humans, Interviews as Topic methods, Patient Acceptance of Health Care, Patient Compliance, Medical History Taking, Physician-Patient Relations, Primary Health Care
- Published
- 1980
- Full Text
- View/download PDF
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