This paper aims to study the effect of Ziziphi Spinosae Semen extracts on chronic unpredictable mild stress(CUMS)-induced depression-like and insomnia behavior models of mice. The CUMS-induced depression-like and insomnia behavior model of mice was established by CUMS treatment for three weeks. The mice were randomly divided into control group, model group, positive drug diazepam group(2 mg·kg~(-1)), as well as low-dose group(1.95 g·kg~(-1)), medium-dose group(3.9 g·kg~(-1)), and high-dose group(7.8 g·kg~(-1)) of Ziziphi Spinosae Semen extracts, with 18 mice in each group. On the 15th day of modeling, the drug was administered intragastrically once a day for one week. Then, the pentobarbital sodium cooperative righting experiment, open field experiment, and elevated plus maze experiment were carried out, respectively. The contents of neurotransmitters 5-hydroxytryptamine(5-HT) and 5-hydroxyindoleacetic acid(5-HIAA) in serum and thalamus of mice, as well as the levels of corticotropin releasing hormone(CRH), adrenocorticotropic hormone(ACTH), and corticosterone(CORT) in serum, were determined by enzyme-linked immunosorbent assay(ELISA). The neuron damage in the hippocampus of mice was observed by hematoxylin-eosin(HE) staining and Nissl staining. Western blot was used to detect the expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), monoamine oxidase A(MAOA), five prime repressors under dual repression binding protein 1(Freud1), synaptic plasticity-related proteins [cellular gene FOS(C-FOS), postsynaptic density protein 95(PSD95), synapsin 1(SYN1), and activity-regulated cytoskeleton-associated gene(ARC)], blood-brain barrier(BBB) permeability-related proteins [zonula occludens 1(ZO-1), occludin, and claudin 1], inflammatory factors [NOD-, LRR-and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein(ASC), gasdermin D(GSDMD), caspase-3, and caspase-8], and antioxidant factors [nuclear factor erythroid 2-related factor 2(NRF2) and heme oxygenase 1(HO1)] in thalamic tissue of mice. The results indicated that compared with that in the model group, the sleep latency was significantly shortened, and the sleep duration was significantly prolonged in each dose group of Ziziphi Spinosae Semen extracts. The number of visits to the central area of the open field and the distance and time of visits were significantly increased in each dose group of Ziziphi Spinosae Semen extracts. In addition, the proportion of distance and time of entering the open arm area of the elevated plus maze was significantly increased in each dose group of Ziziphi Spinosae Semen extracts. The contents of 5-HT and 5-HIAA in serum and thalamus of mice increased to varying degrees in each dose group of Ziziphi Spinosae Semen extracts; the contents of CRH, ACTH, and CORT in serum of mice were significantly decreased. The protein expression of TPH2 was significantly increased. The protein expression of MAOA, SERT, and Freud1 was significantly decreased. Ziziphi Spinosae Semen extracts could also significantly reduce the protein expression of C-FOS but significantly increase the protein expression of PSD95, ARC, and SYN1. They could reduce the pathological damage of the hippocampus in mice and significantly increase the protein expression of ZO-1, occluding, and claudin 1. The protein expression of NLRP3, GSDMD, ASC, caspase-3, and caspase-8 in the thalamic tissue of mice was significantly decreased, and the protein expression of HO1 and NRF2 was significantly increased. In conclusion, Ziziphi Spinosae Semen extracts could effectively improve sleep disorders and depression-like behaviors in CUMS-induced model mice, which may be related to regulating the 5-HT anabolism process and hypothalamic-pituitary-adrenal(HPA) axis-related hormone levels, reducing pathological damage in the hippocampus, improving synaptic plasticity, repairing BBB integrity, and alleviating inflammatory response and oxidative stress damage.
Animals ; Ziziphus/chemistry* ; Mice ; Male ; Depression/psychology* ; Drugs, Chinese Herbal/administration & dosage* ; Sleep Initiation and Maintenance Disorders/psychology* ; Stress, Psychological/complications* ; Behavior, Animal/drug effects* ; Humans ; Disease Models, Animal

The purpose of this study was to clarify the effect of Huotan Jiedu Tongluo Decoction on atherosclerosis(AS) injury in ApoE~(-/-) mice by regulating the ferroptosis pathway. Seventy-five ApoE~(-/-) mice were randomly divided into model group, low-, medium-, and high-dose of Huotan Jiedu Tongluo Decoction groups, and evolocumab group(n=15), and 15 C57BL/6J mice were selected as the blank group. Mice in the blank group were fed with a normal diet, and those in the other groups were fed with a high-fat diet to induce AS. From the 9th week, mice in Huotan Jiedu Tongluo Decoction groups were administrated with Huotan Jiedu Tongluo Decoction at corresponding doses by gavage, and those in the blank group and the model group were given an equal volume of distilled water. Mice in the evolocumab group were treated with evolocumab 18.2 mg·kg~(-1 )by subcutaneous injection every 2 weeks. After 8 weeks of continuous intervention, oil red O staining and hematoxylin-eosin(HE) staining were employed to observe the lipid deposition and plaque formation in the aortic root. Masson staining was used to evaluate the collagen content in the aortic root. The serum levels of total cholesterol(TC), triglycerides(TG), high-density lipoprotein cholesterol(HDL-C), and low-density lipoprotein cholesterol(LDL-C) were determined by biochemical kits. The levels of Fe~(2+), superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione(GSH) in the aorta were measured by colorimetry. The protein and mRNA levels of nuclear factor erythroid 2-related factor 2(Nrf2), glutathione peroxidase 4(GPX4), solute carrier family 7 member 11(SLC7A11), and acyl-CoA synthetase long chain family member 4(ACSL4) in the aorta were detected by Western blot and RT-qPCR, respectively. The expression of Nrf2, GPX4, and SLC7A11 was localized by immunofluorescence. The results showed that low-, medium-, and high-dose Huotan Jiedu Tongluo Decoction reduced the plaque formation of aortic root and increased the collagen content in AS mice. At the same time, Huotan Jiedu Tongluo Decoction improved the lipid metabolism by lowering the levels of TC, LDL-C, and TG and elevating the level of HDL-C in the serum. Huotan Jiedu Tongluo Decoction enhanced the antioxidant capacity by elevating the levels of GSH and SOD and lowering the level of MDA in the aorta and inhibiting the accumulation of Fe~(2+) in the aorta. In addition, Huotan Jiedu Tongluo Decoction up-regulated the protein and mRNA levels of Nrf2, GPX4, and SLC7A11, while down-regulating the protein and mRNA levels of ACSL4. In summary, Huotan Jiedu Tongluo Decoction can effectively alleviate AS lesions in ApoE~(-/-) mice by activating the Nrf2/GPX4 pathway, reducing lipid peroxidation, and inhibiting ferroptosis.
Animals ; Ferroptosis/drug effects* ; Atherosclerosis/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; NF-E2-Related Factor 2/genetics* ; Mice ; Mice, Inbred C57BL ; Apolipoproteins E/metabolism* ; Male ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Signal Transduction/drug effects* ; Humans ; Mice, Knockout

This study investigated the mechanism by which Jianpi Bushen Yiqi Decoction promotes acetylcholine receptor(AChR) clustering in myasthenia gravis through the Agrin/low-density lipoprotein receptor-related protein 4(LRP4)/muscle-specific receptor tyrosine kinases(MuSK) signaling pathway. A total of 114 female C57BL/6J mice were divided into the normal group, modeling group, and solvent control group. The normal group and the solvent control group were immunized with phosphate-buffered saline(PBS), while the modeling group was established as an experimental autoimmune myasthenia gravis(EAMG) model using the murine-derived AChR-α subunit R97-116 peptide fragment. After successful modeling, the mice were randomly assigned to the model group, the low-, medium-, and high-dose Jianpi Bushen Yiqi Decoction groups, and the prednisone group. After four weeks of continuous treatment, muscle strength was assessed using Lennon scores and grip strength tests. Immunofluorescence staining was conducted on differentiated C2C12 myotubes incubated with a drug-containing serum to observe the number of AChR clusters. The integrity of AChR on myofilaments in mouse gastrocnemius muscles was further assessed by immunofluorescence staining. Hematoxylin-Eosin(HE)staining was applied to examine pathological changes in the gastrocnemius muscles of EAMG mice treated with Jianpi Bushen Yiqi Decoction. Western blot was utilized to detect the expression of key proteins in the Agrin/LRP4/MuSK signaling pathway in both C2C12 myotubes and mouse gastrocnemius muscles. The results demonstrated that compared to the model group, the prednisone group exhibited a significant decrease in the body weights of mice, whereas no significant differences in the body weights of mice were observed among the low-, medium-, and high-dose Jianpi Bushen Yiqi Decoction groups. All treatment groups showed significantly improved grip strength and Lennon scores. Additionally, the formula promoted AChR clustering on myotubes and enhanced AChR integrity in gastrocnemius myofilaments and reduced inflammatory infiltration between muscle tissue and fibrous hyperplasia. Furthermore, Jianpi Bushen Yiqi Decoction upregulated the protein expression of AChRα1, Agrin, and p-MuSK in C2C12 myotubes and increased the protein expression of AChRα1, Agrin, MuSK, p-MuSK, LRP4, and docking protein 7(Dok-7)in gastrocnemius tissue. In conclusion, Jianpi Bushen Yiqi Decoction may promote AChR clustering by targeting key proteins in the Agrin/LRP4/MuSK signaling pathway, thereby improving neuromuscular junction function and enhancing muscle strength.
Animals ; Agrin/genetics* ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; Receptors, Cholinergic/genetics* ; Female ; Mice, Inbred C57BL ; Receptor Protein-Tyrosine Kinases/genetics* ; Neuromuscular Junction/metabolism* ; Myasthenia Gravis, Autoimmune, Experimental/physiopathology* ; Humans ; LDL-Receptor Related Proteins

OBJECTIVE: To evaluate the clinical efficacy and safety of Yangxue Qingnao Pills (YXQNP) combined with amlodipine in treating patients with grade 1 hypertension. METHODS: This is a multicenter, randomized, double-blind, and placebo-controlled study. Adult patients with grade 1 hypertension of blood deficiency and Gan (Liver)-yang hyperactivity syndrome were randomly divided into the treatment or the control groups at a 1:1 ratio. The treatment group received YXQNP and amlodipine besylate, while the control group received YXQNP's placebo and amlodipine besylate. The treatment duration lasted for 180 days. Outcomes assessed included changes in blood pressure, Chinese medicine (CM) syndrome scores, symptoms and target organ functions before and after treatment in both groups. Additionally, adverse events, such as nausea, vomiting, rash, itching, and diarrhea, were recorded in both groups. RESULTS: A total of 662 subjects were enrolled, of whom 608 (91.8%) completed the trial (306 in the treatment and 302 in the control groups). After 180 days of treatment, the standard deviations and coefficients of variation of systolic and diastolic blood pressure levels were lower in the treatment group compared with the control group. The improvement rates of dizziness, headache, insomnia, and waist soreness were significantly higher in the treatment group compared with the control group (P<0.05). After 30 days of treatment, the overall therapeutic effects on CM clinical syndromes were significantly increased in the treatment group as compared with the control group (P<0.05). After 180 days of treatment, brachial-ankle pulse wave velocity, ankle brachial index and albumin-to-creatinine ratio were improved in both groups, with no statistically significant differences (P>0.05). No serious treatment-related adverse events occurred during the study period. CONCLUSIONS Combination therapy of YXQNP with amlodipine significantly improved symptoms such as dizziness and headache, reduced blood pressure variability, and showed a trend toward lowering urinary microalbumin in hypertensive patients. These findings suggest that this regimen has good clinical efficacy and safety. (Registration No. ChiCTR1900022470).
Humans ; Amlodipine/adverse effects* ; Drugs, Chinese Herbal/adverse effects* ; Male ; Female ; Hypertension/complications* ; Middle Aged ; Treatment Outcome ; Drug Therapy, Combination ; Adult ; Blood Pressure/drug effects* ; Double-Blind Method ; Aged ; Antihypertensive Agents/adverse effects*

OBJECTIVE: To evaluate the dynamic changes of glucocorticoid (GC) dose and the feasibility of GC discontinuation in rheumatoid arthritis (RA) patients under the background of Chinese medicine (CM). METHODS: This multicenter retrospective cohort study included 1,196 RA patients enrolled in the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) from September 1, 2019 to December 4, 2023, who initiated GC therapy. Participants were divided into the Western medicine (WM) and integrative medicine (IM, combination of CM and WM) groups based on medication regimen. Follow-up was performed at least every 3 months to assess dynamic changes in GC dose. Changes in GC dose were analyzed by generalized estimator equation, the probability of GC discontinuation was assessed using Kaplan-Meier curve, and predictors of GC discontinuation were analyzed by Cox regression. Patients with <12 months of follow-up were excluded for the sensitivity analysis. RESULTS: Among 1,196 patients (85.4% female; median age 56.4 years), 880 (73.6%) received IM. Over a median 12-month follow-up, 34.3% (410 cases) discontinued GC, with significantly higher rates in the IM group (40.8% vs. 16.1% in WM; P<0.05). GC dose declined progressively, with IM patients demonstrating faster reductions (median 3.75 mg vs. 5.00 mg in WM at 12 months; P<0.05). Multivariate Cox analysis identified age <60 years [P<0.001, hazard ratios (HR)=2.142, 95% confidence interval (CI): 1.523-3.012], IM therapy (P=0.001, HR=2.175, 95% CI: 1.369-3.456), baseline GC dose ⩽7.5 mg (P=0.003, HR=1.637, 95% CI: 1.177-2.275), and absence of non-steroidal anti-inflammatory drugs use (P=0.001, HR=2.546, 95% CI: 1.432-4.527) as significant predictors of GC discontinuation. Sensitivity analysis (545 cases) confirmed these findings. CONCLUSIONS RA patients receiving CM face difficulties in following guideline-recommended GC discontinuation protocols. IM can promote GC discontinuation and is a promising strategy to reduce GC dependency in RA management. (Trial registration: ClinicalTrials.gov, No. NCT05219214).
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Arthritis, Rheumatoid/drug therapy* ; Glucocorticoids/therapeutic use* ; Medicine, Chinese Traditional ; Retrospective Studies

OBJECTIVE: To investigate the association between ABO blood types and gestational diabetes mellitus (GDM) risk. METHODS: A prospective birth cohort study was conducted. ABO blood types were determined using the slide method. GDM diagnosis was based on a 75-g, 2-h oral glucose tolerance test (OGTT) according to the criteria of the International Association of Diabetes and Pregnancy Study Groups. Logistic regression was applied to calculate the odds ratios ( ORs) and 95% confidence intervals ( CIs) between ABO blood types and GDM risk. RESULTS: A total of 30,740 pregnant women with a mean age of 31.81 years were enrolled in this study. The ABO blood types distribution was: type O (30.99%), type A (26.58%), type B (32.20%), and type AB (10.23%). GDM was identified in 14.44% of participants. Using blood type O as a reference, GDM risk was not significantly higher for types A ( OR = 1.05) or B ( OR = 1.04). However, women with type AB had a 19% increased risk of GDM ( OR = 1.19, 95% CI = 1.05-1.34; P < 0.05), even after adjusting for various factors. This increased risk for type AB was consistent across subgroup and sensitivity analyses. CONCLUSION The ABO blood types may influence GDM risk, with type AB associated with a higher risk. Incorporating it-either as a single risk factor or in combination with other known factors-could help identify individuals at risk for GDM before or during early pregnancy.
Humans ; Female ; Pregnancy ; Diabetes, Gestational/etiology* ; ABO Blood-Group System ; Adult ; Prospective Studies ; Risk Factors ; Young Adult

Objective To investigate the expression of the histone deacetylase SIRT7 in glioma cells and its impact on epithelial-mesenchymal transformation(EMT),as well as its effects on proliferative,migratory and invasive capabilities of glioma cells.Methods Bioinformatics analysis was conducted on data from glioma patients in the Cancer Genome Atlas(TCGA)and the Chinese glioma Genome Atlas(CGGA)databases to explore the expression of SIRT7 gene in gliomas and its correlation with tumor grading,molecular characteristics and patient clinical prognosis.Glioma cells were randomly divided into control,SIRT7 knockdown,SIRT7 overexpression,drug treatment(10 μmol/L hydrochlorothiazide)and drug(10 μmol/L hydrochlorothiazide)+SIRT7 overexpression groups.The CCK-8 assay,cell scratch assay and Transwell assay were used to observe the effects of upregulating and downregulating SIRT7 expression on glioma cell proliferation,migration and invasion.RT-qPCR and Western blotting were employed to detect the effects of SIRT7 on the expression of neural cadherin(N-cadherin),Vimentin,E-cadherin,transforming growth factor-β(TGF-β),Ki-67,and Smad3 protein in glioma cells.Nude mouse tumor-bearing experiments were conducted to observe the effect of SIRT7 knockdown on glioma growth.Results Higher expression levels of SIRT7 gene were associated with poorer clinical prognosis(P＜0.0001).SIRT7 expression levels were significantly correlated with tumor grading and 1p19q coding status(P＜0.01).Compared with normal HA cells,glioma cells showed significantly increased SIRT7 expression levels(P＜0.01).CCK-8 assay results indicated that,compared with control group,the proliferation activity of glioma cells in SIRT7 knockout group was significantly decreased(P＜0.01),while SIRT7 overexpression group showed significantly increased proliferation activity(P＜0.01).EdU assay results showed that,compared with control group,the proportion of glioma cells in the proliferative stage was significantly decreased in SIRT7 knockdown group(P＜0.01),and significantly increased in SIRT7 overexpression group(P＜0.01).Western blotting results revealed that,compared with control group,the protein expression levels of TGF-β,Smad3,N-cadherin and Vimentin were significantly decreased in SIRT7 knockdown group(P＜0.01),while the expression level of E-cadherin protein was significantly increased(P＜0.05).SIRT7 overexpression group showed significantly increased protein expression levels of TGF-β,Smad3,N-cadherin and Vimentin(P＜0.05),and a significantly decrease in E-cadherin protein expression level(P＜0.05).Scratch assay results indicated that,compared with control group,the migration ability of cells in SIRT7 knockdown group and drug group was significantly decreased(P＜0.01),and SIRT7 overexpression group showed significantly increased cell migration ability(P＜0.05).Compared with drug group,drug+SIRT7 overexpression group exhibited significantly increased cell migration ability(P＜0.01).Transwell assay results showed that,compared with control group,the migration and invasion abilities of cells in SIRT7 knockdown group and drug group were significantly decreased(P＜0.01),and SIRT7 overexpression group exhibited significantly increased migration and invasion abilities(P＜0.01).Compared with drug group,drug+SIRT7 overexpression group showed significantly increased migration and invasion abilities(P＜0.01).Nude mouse tumor-bearing assay results indicated that the volume and weight of glioma in SIRT7 knockdown group were significantly reduced compared with control group(P＜0.01).Conclusions Glioma patients with high SIRT7 expression have poorer clinical prognosis.SIRT7 can regulate the TGF-β/Smad3 pathway to mediate EMT,promoting the proliferation and migration of glioma cells.SIRT7 knockdown can inhibit the growth of transplanted gliomas in nude mice.

Objective To evaluate healthcare-associated infection(HAI)status and influencing factors in coronary heart disease(CHD)patients after percutaneous coronary intervention(PCI)treatment,and construct a risk predic-tion model.Methods CHD patients who underwent PCI in a hospital from May 2019 to October 2023 were retro-spectively selected as the research subjects.Infection status of the CHD patients was analyzed.Patients were ran-domly divided into a modeling set and a testing set in a 7:3 ratio.Univariate and multivariate logistic regression ana-lyses were performed to analyze the data in the modeling set and determine the influencing factors for HAI in pa-tients.R software was used to construct and validate a nomogram model.Results A total of 858 CHD patients were included in the analysis,601 in the modeling set and 257 in the testing set.In the modeling set,41 cases were in the infected group and 560 cases in the non-infected group.The incidence of HAI in CHD patients after PCI treat-ment was 6.88％(59/858).Infection site were mainly upper respiratory tract and urinary tract.A total of 74 pathogens were isolated,including Gram-positive bacteria,Gram-negative bacteria,and fungi being 39,31,and 4 strains,respectively.Multivariate analysis showed that old age,combined diabetes,high grade of New York Heart Association(NYHA)classification,and invasive procedures were all risk factors for HAI in CHD patients after PCI treatment(all P＜0.05),while high mini-nutritional assessment short-form(MNA-SF)score was a protective fac-tor(P＜0.05).The area under the receiver operating characteristic(ROC)curve(AUC)of the nomogram predic-tion model constructed based on the above five indicators was 0.894(95％CI:0.815-0.931),with a sensitivity of 89.0％and a specificity of 82.5％.The testing set data validation showed an AUC value of 0.879(95％CI:0.801-0.923),with a sensitivity of 87.5％and a specificity of 81.3％,which were comparable to the modeling set and presented the stability of the model.The H-L goodness of fit test showed no statistical significance(P＞0.05),in-dicating that the model didn't exhibit overfitting.Calibration curve analysis showed that the model had good consis-tency.Decision curve analysis confirmed that the model had practical value in clinical practice.Conclusion The no-mogram model has a good predictive ability for HAI in CHD patients after PCI treatment,and can provide a simple and effective evaluation tool for medical staff to identify HAI high-risk individuals.

Aim To investigate the effect of quercetin on the aging model of bone marrow mesenchymal stem cells established under microgravity. Methods Using 3D gyroscope, a aging model of bone marrow mesenchymal stem cells was constructed, and after receiving quercetin and microgravity treatment, the anti-aging effect of the quercetin was evaluated by detecting related proteins and oxidation indexes. Results Compared to the control group, the expressions of age-related proteins p21, pi6, p53 and RB in the microgravity group significantly increased, while the expressions of cyclin D1 and lamin B1 significantly decreased, with statistical significance (P<0.05). In the microgravity group, mitochondrial membrane potential significantly decreased (P<0.05), ROS accumulation significantly increased (P <0.05), SOD content significantly decreased and MDA content significantly increased (P<0.05). Compared to the microgravity group, the expressions of age-related proteins p21, pi6, p53 and RB in the quercetin group significantly decreased, while the expressions of cyclin D1 and lamin B1 significantly increased, with statistical significance (P<0.05). In the quercetin group, mitochondrial membrane potential significantly increased (P<0.05), ROS accumulation significantly decreased (P<0.05), SOD content significantly increased and MDA content significantly decreased (P<0.05). Conclusions Quercetin can resist oxidation, protect mitochondrial function and normal cell cycle, thus delaying the aging of bone marrow mesenchymal stem cells induced by microgravity.

italic>Acanthopanax senticosus is one of the genuine regional herb in Northeast China. In this study, we identified the germplasm resources of commercial A. senticosus samples based on atpI and atpB_rbcL according to the previous chloroplast genome sequencing results, and determinated the content of syringin by HPLC to evaluated the quality of commercial samples. A total of 80 A. senticosus samples were collected from 47 cities in 24 provinces. DNA was extracted to amplify the products of atpI and atpB_rbcL by PCR. The results showed that 7 haplotypes (H2, H5, H8, H10, H12, H14, H23) were formed by the combined analysis of the two gene fragments. H2 from Yichun in Heilongjiang, Shangzhi in Harbin, Suihua in Heilongjiang, Fushun in Liaoning, Benxi in Liaoning, Changbai in Jilin and Jingyu in Jilin were the dominant genotype, representing 58.75% of the total samples. H14 and H23 were the unique haplotypes of the producing area. It is speculated that the commercial A. senticosus samples with haplotypes of H14 and H23 are from Raohe, Shuangyashan, Heilongjiang and Mingshui, Suihua, Heilongjiang, respectively. HPLC analysis indicated that the content of syringin in 73.96% of the samples met the Pharmacopoeia standards. There was a significant difference in the content of syringin among the samples, ranging from 0.003 7% to 0.524 5%, with a difference of 0.520 8%, indicating that the quality of the samples in the market of A. senticosus was uneven. However, there were no significant differences in the contents of syringin in the commercial A. senticosus among different haplotypes. The content of syringin in the haplotype H23 in the market sample is relatively high, so it may be a germplasm with better quality. This study researched the germplasm resources and medicinal materials quality of commercial A. senticosus samples and will help guide the commercial circulation, reasonable medication of A. senticosus, and the screening of excellent germplasm.