ABSTRACT
Objective:To analyze the costs and effectiveness of five common screening modes and genetic screening for thalassemia in China in order to find the optimal way and provide evidence for the implementation of thalassemia prevention and control projects in Hunan Province.Methods:From June 2020 to April 2021, 12 971 couples from 14 cities and autonomous prefectures in Hunan Province were selected as the study population. The diagnosis of thalassemia was based on the results of genetic testing. Results of routine blood test and hemoglobin electrophoresis were collected and analyzed. The efficacy of five screening modes, at the cut-off value of <80 fl or 82 fl for the mean corpuscular volume (MCV), was analyzed by positive predictive value, negative predictive value, Jorden index and cost-effectiveness ratio. Sensitivity analysis was used to assess the feasibility of genetic screening at different costs after fixing the costs of routine blood and hemoglobin electrophoresis. The five thalassemia screening models are as follows: Mode 1: The woman had a blood routine test first. If the result was positive, the spouse required a blood routine test. If both results were positive, a thalassemia gene test should be offered to the couple. Mode 2: Both husband and wife were screened by blood routine and hemoglobin electrophoresis. If one or both of them were positive, both would be tested for thalassemia gene. Mode 3: The couple received blood routine tests initially. If either was positive, both should receive hemoglobin electrophoresis testing. If either was positive, both parties will conduct thalassemia gene testing. Mode 4: The woman was screened by blood routine and hemoglobin electrophoresis. If any one of them was positive, the woman would be tested for thalassemia gene. If the gene test result was positive, the spouse should receive thalassemia gene. Mode 5: Both spouses conducted a blood routine test. If either was positive, both would conduct hemoglobin electrophoresis test. If both were positive, both spouses should receive thalassemia gene testing. Gene testing mode: The woman would be tested for thalassemia, and her spouse would have thalassemia test too if her result was positive.Results:When using MCV<80 fl as the cut-off for diagnosing thalassemia, the Youden indices of the five prenatal screening modes in Hunan Province were 0.551, 0.639, 0.898, 0.555 and 0.356, while when using MCV<82 fl as the cut-off, the Youden indices were 0.549, 0.629, 0.851, 0.548 and 0.356. When the MCV cut-off value was <80 fl, the missed diagnosis rates of the five screening modes were 44.44%, 0.00, 0.00, 18.52% and 62.96%, and the cost-effectiveness ratios were 21 709, 250 939, 76 870, 138 463 and 92 860 yuan (RMB)/couple, respectively. When the price of genetic testing was lower than 55 yuan (RMB), the cost-effectiveness ratio of genetic screening was lower than that of Mode 3.Conclusions:MCV<80 fl can be considered as the positive criteria in blood routine screening for thalassemia in Hunan Province, and the cost-effectiveness ratio of Mode 3 (the couple received blood routine tests initially. If either was positive, both should receive hemoglobin electrophoresis testing. If either was positive, both parties will conduct thalassemia gene testing) is the best. Genetic screening has certain advantages with the decreasing price.
ABSTRACT
Eichhornia crassipes is an aquatic plant native to the Amazon River Basin. It has become a serious weed in freshwater habitats in rivers, lakes and reservoirs both in tropical and warm temperate areas worldwide. Some research has stated that it can be used for water phytoremediation, due to its strong assimilation of nitro- gen and phosphorus, and the accumulation of heavy metals, and its growth and spread may play an important role in environmental ecology. In order to explore the molecular mechanism of E. crassipes to responses to nitrogen deficiency, we constructed forward and reversed subtracted cDNA libraries for E. crassipes roots under nitrogen deficient condition using a suppressive subtractive hybridization (SSH) method. The forward subtraction included 2 100 clones, and the reversed included 2 650 clones. One thousand clones were randomly selected from each library for sequencing. About 737 (527 unigenes) clones from the forward library and 757 (483 unigenes) clones from the reversed library were informative. Sequence BlastX analysis showed that there were more transporters and adenosylhomocysteinase-like proteins in E. crassipes cultured in nitrogen deficient medium; while, those cultured in nitrogen replete medium had more proteins such as UBR4-like e3 ubiquitin- protein ligase and fasciclin-like arabinogalactan protein 8-like, as well as more cytoskeletal proteins, including actin and tubulin. Cluster of Orthologous Group (COG) analysis also demonstrated that in the forward library, the most ESTs were involved in coenzyme transportation and metabolism. In the reversed library, cytoskeletal ESTs were the most abundant. Gene Ontology (GO) analysis categories demonstrated that unigenes involved in binding, cellular process and electron carrier were the most differentially expressed unigenes between the forward and reversed libraries. All these results suggest that E. crassipes can respond to different nitrogen status by efficiently regulating and controlling some transporter gene expressions, certain metabolism processes, specific signal transduction pathways and cytoskeletal construction.
Se ha convertido en una maleza importante en hábitats de agua dulce en ríos, lagos y embalses, tanto en zonas tropicales como templadas de todo el mundo. Algunas investigaciones han indicado que se puede utilizar para la fitorremediación de agua, debido a su fuerte asimilación de nitrógeno y fósforo, y la acumulación de metales pesados, su crecimiento y propagación puede desempeñar un papel importante en la ecología ambiental. Con el fin de explorar el mecanismo molecular de respuesta a la deficiencia de nitrógeno en E. crassipes, se construyeron bibliotecas de cDNA mediante síntesis adelantada y retrasada para raíces de E. crassipes en condiciones de deficiencia de nitrógeno mediante el método de hibridación supresiva sustractiva (SSH). Para este estudio se utilizaron 2 100 clones de síntesis adelantada y 2 650 de síntesis retrasada. De la biblioteca se escogieron al azar mil clones, 737 (527 unigenes) de síntesis adelanta- da y 757 (483 unigenes) de síntesis retrasada que fueron informativos. El análisis BLASTX mostró que había más transportadores y proteínas adenosilhomocisteinasa en E. crassipes cultivadas en un medio deficiente de nitrógeno; mientras que las cultivadas en un medio repleto de nitróge- no tenían más proteínas como UBR4 e3 ubiquitina-proteína ligasa y la proteína arabinogalactano 8 tipo fasciclina, así como otras proteínas del citoesqueleto, incluyendo la actina y la tubulina. Clúster del Grupo Ortológico (COG) también demostró que en la biblioteca de síntesis adelan- tada, la mayoría de los marcadores de secuencia expresada (ESTs) estaban involucrados en el transporte de coenzimas y el metabolismo.