[Effects of normal mitochondrial transplantation on proliferation, apoptosis and stemness of triple-negative breast cancer cells].

Objectives: To observe the mitochondrial morphology of normal and triple-negative breast cancer cells, extract mitochondria from normal cells, and investigate the effects of mitochondrial transplantation on proliferation, apoptosis, and stemness of triple-negative breast cancer cells. Methods: The morphology of mitochondria was observed by transmission electron microscope. Mitochondria were extracted by mitochondrial extraction kit, mitochondrial protein was identified by western blot, and mitochondrial activity was detected by mitochondrial membrane potential detection kit. MitoTracker Green or MitoTracker Deep Red fluorescent probes were used to label the mitochondria of living cells, and the degree of mitochondria entering LTT cells was observed by confocal laser microscopy at 12, 24, and 96 hours. The effects of mitochondrial transplantation on proliferation, apoptosis, and stemness of breast cancer cells were examined by CCK8, colony formation assay, flow cytometry, and sphere formation assay after 24 hours of mitochondrial transplantation. Results: The mitochondria of normal cells were rod-shaped or elongated, while the mitochondria of triple-negative breast cancer cells were swollen and vacuolated. Western blot results showed that cytochrome c oxidase subunit I (MT-CO1) protein encoded by mitochondria was present in the isolated mitochondria. The content of heat shock protein 60 (HSP60) was higher in mitochondria than that in cytoplasm. The result of the multi-mode microplate reader showed that the content of mitochondrial J-aggregates/monomer was 1.67±0.06, which was significantly higher than 0.35±0.04 of the control group (P＜0.001). Exogenous mitochondria were observed in LTT cells at 12, 24, and 96 hours after mitochondrial transplantation. The results of the CCK8 experiment showed that OD450 of LTT cells was 0.27±0.13 after 48 hours transplantation, which was lower than 0.62±0.36 of the control group (P=0.023). The OD450 of MDA-MB-468 cells was 0.30±0.03, which was lower than 0.65±0.10 of the control group (P=0.004). After 120 hours of mitochondrial transplantation, OD450 in both groups was still significantly lower than that in the control group (P＜0.01). The number of clones formed by mitochondrial transplantation of LTT cells was 21.33±7.31, which was lower than 35.22±13.59 of the control group (P=0.016). Flow cytometry showed that the early apoptosis rate of LTT cells was (30.07±2.15)% after 24 hours of mitochondrial transplantation, which was higher than 2.07±1.58 of the control group (P＜0.001). The proportion of early apoptosis in MDA-MB-468 cells was 24.47%±5.22%, which was higher than (7.83±2.06)% in the control group (P=0.007). In addition, the number of mitochondria transplanted LTT cells into the cell sphere was 46.25±5.40, which was significantly lower than 62.58±6.43 of the control group (P＜0.001). Conclusion: Normal mitochondria can enter triple-negative breast cancer cells by co-culture, inhibit the proliferation and stemness of triple-negative breast cancer cells, and promote the apoptosis of triple-negative breast cancer cells.

[Long-term hypomethylating agents in patients with myelodysplastic syndromes: a multi-center retrospective study].

Objective: To evaluate the efficacy and safety of hypomethylating agents (HMA) in patients with myelodysplastic syndromes (MDS) . Methods: A total of 409 MDS patients from 45 hospitals in Zhejiang province who received at least four consecutive cycles of HMA monotherapy as initial therapy were enrolled to evaluate the efficacy and safety of HMA. Mann-Whitney U or Chi-square tests were used to compare the differences in the clinical data. Logistic regression and Cox regression were used to analyze the factors affecting efficacy and survival. Kaplan-Meier was used for survival analysis. Results: Patients received HMA treatment for a median of 6 cycles (range, 4-25 cycles) . The complete remission (CR) rate was 33.98% and the overall response rate (ORR) was 77.02%. Multivariate analysis revealed that complex karyotype (P=0.02, OR=0.39, 95%CI 0.18-0.84) was an independent favorable factor for CR rate. TP53 mutation (P=0.02, OR=0.22, 95%CI 0.06-0.77) was a predictive factor for a higher ORR. The median OS for the HMA-treated patients was 25.67 (95%CI 21.14-30.19) months. HMA response (P=0.036, HR=0.47, 95%CI 0.23-0.95) was an independent favorable prognostic factor, whereas complex karyotype (P=0.024, HR=2.14, 95%CI 1.10-4.15) , leukemia transformation (P<0.001, HR=2.839, 95%CI 1.64-4.92) , and TP53 mutation (P=0.012, HR=2.19, 95%CI 1.19-4.07) were independent adverse prognostic factors. There was no significant difference in efficacy and survival between the reduced and standard doses of HMA. The CR rate and ORR of MDS patients treated with decitabine and azacitidine were not significantly different. The median OS of patients treated with decitabine was longer compared with that of patients treated with azacitidine (29.53 months vs 20.17 months, P=0.007) . The incidence of bone marrow suppression and pneumonia in the decitabine group was higher compared with that in the azacitidine group. Conclusion: Continuous and regular use of appropriate doses of hypomethylating agents may benefit MDS patients to the greatest extent if it is tolerated.

[Exploring potential serum metabolite markers of intrahepatic cholestasis based on liquid chromatography-mass spectrometry metabolomics technology].

Objective: To analyze the blood differential metabolites of patients with intrahepatic cholestasis (IHC) by liquid chromatography-mass spectrometry metabolomics technology so as to find potential metabolic target. Method: Serum samples were collected from thirty patients with intrahepatic cholestasis and thirty healthy individuals after metabolomics analysis. The differential metabolites were initially screened based on the multiple differences and significance. KEGG enrichment analysis was performed on the differential metabolites to determine the candidate targets. The potential clinical application value of these characteristic metabolites was analyzed using the receiver operating characteristic curve. Result: A total of thirty patients with intrahepatic cholestasis and thirty healthy adults were included. The age difference between the two groups was not statistically significant (P>0.05). The clinical condition was consistent with the statistically significant differences in liver biochemical indicators, blood routine, coagulation, and inflammatory indicators between the two groups (P<0.05). Furthermore, a blood metabolomics screening analysis revealed 99 differentially expressed metabolites associated with intrahepatic cholestasis. Of these, 15 showed statistically significant differences. Glucose, lipid, and energy metabolisms were the various primary types of differential metabolites involved. The receiver operating characteristic curve>0.9 included the following twelve kinds of metabolites: 1H-indole-3-carboxaldehyde, 6-hydroxy-1H-indole-3-acetamide, phenylalanyl tryptophan, 1-methylguanosine, 2-ethoxy-5-methylpyrazine, p-hydroxybenzaldehyde, 5-(2-chlorophenyl)-3,4-dihydro-2H-pyrrole, methylthioadenosine, alanylisoleucine, anabsinthin, N-acetyl-DL-histidine monohydrate, N-methylnicotinamide, and others. The fifteen metabolites that were previously identified and calculated according to the differential quantitative value of the metabolite corresponding ratio exhibited fold-changes in the upregulated and downregulated potential biomarkers (phenylalanine tryptophan, phenylalanine, 5'-methylthioadenosine, anabsinthin, and N-methylnicotinamide) in combination with the area under the receiver operating characteristic curve>0.9. Conclusion: Phenylalanyl tryptophan, phenylalanylalanine, 5'-methylthioadenosine, anabsinthin, and N-methylnicotinamide may serve as potential metabolic markers to distinguish patients with cholestasis from healthy controls. N-methylnicotinamide, among them, is of great importance as a potential marker.

PRDM1 promotes the ferroptosis and immune escape of thyroid cancer by regulating USP15-mediated SELENBP1 deubiquitination.

BACKGROUND: The deubiquitinating enzyme Ubiquitin-specific peptidase 15 (USP15) is upregulated in various cancers and promotes tumor progression by increasing the expression of several oncogenes. This project is designed to explore the role and mechanism of USP15 in thyroid cancer (TC) progression. METHODS: Selenium-binding protein 1 (SELENBP1), USP15, CCL2/5, CXCL10/11, IL-4, and TGF-ß1 mRNA levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). SELENBP1, USP15, GPX4, IL-10, Arg-1, Granzyme B, TNF-α, and PR domain zinc finger protein 1 (PRDM1) protein levels were examined by western blot assay. Fe+ level, malondialdehyde (MDA), and lipid-ROS levels were determined using special kits. The proportion of CD11b+CD206+ positive cells was detected using a flow cytometry assay. The role of SELENBP1 on TC cell growth was examined using a xenograft tumor model in vivo. After GeneMANIA prediction, the interaction between USP15 and SELENBP1 was verified using Co-immunoprecipitation (CoIP) assay. The binding between PRDM1 and USP15 promoter was predicted by JASPAR and validated using Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. RESULTS: SELENBP1 was increased in TC subjects and cell lines, and its knockdown repressed TC cell proliferation, migration, invasion, immune escape, and induced ferroptosis in vitro, as well as blocked tumor growth in vivo. In mechanism, USP15 interacted with SELENBP1 and maintained its stabilization by removing ubiquitin. Meanwhile, the upregulation of USP15 was induced by the transcription factor PRDM1. CONCLUSION: USP15 transcriptionally mediated by PRDM1 might boost TC cell malignant behaviors through deubiquitinating SELENBP1, providing a promising therapeutic target for TC treatment.

[Analysis of clinical characteristics and causes of death in 38 patients with pneumoconiosis].

Objective: To analyze the clinical characteristics and causes of death of patients with pneumoconiosis, and to provide evidence for the prevention and management of pneumoconiosis. Methods: From June 2022 to July 2023, 38 dead patients with pneumoconiosis confirmed by Shandong Academy of Occupational Health and Occupational Medicine were selected as the research objects. The clinical data of patients were collected through hospital information system (HIS) and laboratory information management system (LIS) to analyze the basic situation of patients with pneumoconiosis who died, the distribution of industry types, the course of disease, the nature of work, the type of reimbursement, complications/comorbidities, and the direct causes of death. Univariate analysis of variance was used to compare the course of pneumoconiosis death in patients with different age of exposure to dust. Results: Among the 38 patients with pneumoconiosis, there were 37 males and 1 female. The age of exposure to dust was 5-37 (19.29±8.17) years, the duration of disease was 5-41 (20.26±8.53) years, and the age of death was 27-86 (70.42±12.26) years old. There were 10 cases of stage Ⅰ pneumoconiosis, 18 cases of stage Ⅱ, 10 cases of stage Ⅲ pneumoconiosis and 32 cases (84.21%) of silicosis. There were 30 (78.95%) people aged ≥65 years and 8 (21.05%) people aged <65 years. The industry was mainly metal products (18 workers, 47.37%), and the distribution of work was mainly excavation workers (11 workers, 28.95%). The death course of pneumoconiosis patients with 10-<30 years of exposure to dust accounted for 76.32% (29/38). The average course of pneumoconiosis patients with 20-<30 years of exposure to dust was the longest[ (24.00±9.39) years], and there was no statistically significant difference in the average course of disease among different age of exposure to dust groups (F=1.81, P=0.165). The working units of the deceased patients were private enterprises or factories, and the hospitalization expenses were borne by individuals for 21 people (55.26%). The working unit was a state-owned enterprise, and 17 people (44.74%) were reimbursed for hospitalization expenses and work-related injuries. The main comorbidities/complications of pneumoconiosis patients were respiratory infection in 18 cases (47.37%) and chronic pulmonary heart disease (47.37%). The top 3 direct causes of death were pneumoconiosis in 13 cases (34.21%), pulmonary infection in 10 cases (26.32%) and lung cancer in 7 cases (18.42%) . Conclusion: Most of 38 cases of pneumoconiosis patients death diseases such as multiple combination of respiratory system, cardiovascular system, respiratory system disease is a major cause of death in pneumoconiosis patients.

[Auxiliary diagnosis of visceral leishmaniasis with metagenomic next-generation sequencing: a case report].

This case report summarizes the experience from diagnosis and treatment of a patient with repeated high fever, hepatosplenomegaly and pancytopenia. Following exclusion of bacterial, viral, fungal infections and hematological diseases, metagenomic next-generation sequencing of the patient's peripheral blood revealed Leishmania infantum infection, and rK39 rapid diagnostic test showed positive for anti-Leishmania antibody, while microscopic examination of bone marrow smears identified Leishmania amastigotes. Therefore, the case was definitively diagnosed as visceral leishmaniasis, and given anti-infective treatment with sodium antimony gluconate and hormone, hepatoprotection, elevation of white blood cell counts and personalized nursing. Then, the case was cured and discharged from hospital. Metagenomic next-generation sequencing is of great value in etiological detection of fever patients with unknown causes, which deserves widespread clinical applications.

[Expression of DARS2 in colorectal cancer and its clinical significance].

Objective: To investigate the expression of DARS2 and its clinical significance in colorectal cancer. Methods: In this study, bioinformatics tools, especially gene expression profile interactive analysis 2 (GEPIA2), were used to conduct an in-depth analysis of DARS2 expression in colorectal cancer tissues. Immunohistochemical staining was carried out in 108 colorectal cancer specimens and 30 normal colorectal tissues obtained from the First Affiliated Hospital of Nanchang University, Nanchang, China. Colorectal cancer cell lines (HCT116 and SW480) were transfected with small interfering RNA (siRNA) and DARS2 overexpression plasmid to examine the effects of DARS2 knockdown and overexpression on cell function. To assess the effects on cell function, CCK8 and transwell migration assays were used to assess proliferation and cell motility, respectively. Additionally, protein immunoblotting was employed to scrutinize the expression of proteins associated with the epithelial-mesenchymal transition of colorectal cancer cells. Results: DARS2 exhibited a pronounced upregulation in expression within colorectal cancer tissues compared to their normal epithelial counterparts. Furthermore, DARS2 expression was higher in colorectal cancer of stage Ⅲ-Ⅳ than those of stage Ⅰ-Ⅱ, exhibiting a significant correlation with N staging, M staging, and pathological staging (P<0.05). Kaplan-Meier analyses showed a decreased overall survival rate in colorectal cancer with DARS2 expression compared to those without DARS2 expression (P<0.05). In the siRNA transfection group, there was a significant reduction in cell proliferation and migration (P<0.01 and P<0.05, respectively). Conversely, the transfection of DARS2 overexpression plasmids substantially increased both cell proliferation and migration (P<0.05). Additionally, immunoblotting revealed that DARS2 knockdown led to an upregulation of E-cadherin expression and a downregulation of N-cadherin and vimentin expression. In contrast, DARS2 overexpression resulted in increased N-cadherin and vimentin expression, coupled with reduction in E-cadherin expression. Conclusions: There is a strong association between DARS2 expression and colorectal cancer progression. Silencing DARS2 inhibits cell proliferation and migration, exerting a discernible influence on the epithelial-mesenchymal transition process.

Assessment of sulfonamide contamination in aquatic environments: A first report for Argentina and environmental risk assessment.

The global surge in pharmaceutical consumption, driven by increasing population and the demand for animal proteins, leads to the discharge of diverse pollutants, including antibiotic residues, into water bodies. Sulfonamides, being water-soluble compounds, can readily enter surface run-off, posing potential risks to non-target species despite their low environmental concentrations. Latin America has implemented intensive production systems highly dependent on antimicrobials for productivity and animal health, yet there is a paucity of information regarding their concentration in the region. The objective of this study was to evaluate the presence of sulfonamides in water and sediment samples and assess their potential ecological risks through an environmental risk assessment. The Río de la Plata basin collects the waters of the Paraguay, Paraná, and Uruguay rivers, together with their tributaries and various wetlands, passing through the provinces in Argentina known for their significant animal husbandry production. Two sampling campaigns were carried out for sediment, while only one campaign was conducted for surface waters. The samples were analyzed by high performance liquid chromatography tandem mass-spectrometry (HPLC-MS/MS). None of the examined sulfonamide antibiotics were detected in the sediment samples from both sampling campaigns. In contrast, sulfadiazine (95 %), sulfamethoxazole (91 %), and sulfathiazole (73 %) were detected in the water samples. Sulfadiazine was found in the concentration range of 8 to 128 ng/L, while sulfamethoxazole and sulfathiazole were observed at concentrations ranging from 3.0 to 32.5 ng/L and 2.9 to 8.1 ng/L, respectively. Based on the environmental risk assessment conducted using the sulfonamide concentrations, most samples indicated a medium risk for aquatic biota, with only one sample surpassing the high-risk threshold. This study represents the first report presenting data on the presence of sulfonamide antibiotics in the aquatic environment of Argentina.

Association between health insurance programs and rehabilitation services utilisation among people with disabilities: evidence from China.

OBJECTIVES: Rehabilitation is crucial to improve the health status of people with disabilities. Previous studies mainly analysed the impact of health insurance on utilisation of general health services; the relationship between health insurances and rehabilitation services utilisation among Chinese people with disabilities has been long neglected. This study aimed to analyse the association between health insurance programs and rehabilitation services utilisation among disabled people. STUDY DESIGN: This was a cross-sectional study. METHODS: The data used in this study were derived from 2021 National Household Income Survey of Disabled People and National Basic Database of People with Disabilities conducted by China Disabled Persons' Federation. Logistic regression model was used to analyse the relationship between health insurance and rehabilitation services utilisation, and the propensity score matching method was used to check the robustness of the results. RESULTS: (1) Disabled people insured by the Basic Medical Insurance System for Urban Employees (BMISUE) and the Basic Medical Insurance System for Urban and Rural Residents (BMISURR) were positively associated with rehabilitation service utilisation (odds ratio [OR] = 1.852, 95% confidence interval [CI]:1.268, 2.707; OR = 1.375, 95% CI: 0.962, 1.966). (2) The utilisation level of rehabilitation service among disabled people insured by BMISUE was significantly higher than those insured by BMISURR (OR = 1.355, 95% CI: 1.161, 1.581). (3) The supply of rehabilitation services at the community level was positively correlated with the utilisation by people with disabilities. CONCLUSION: Health insurance can improve the financial accessibility of using rehabilitation services, and the utilisation level will increase as the benefits level of health insurance increase.

Clinical study of antibacterial medical textiles containing polyhydroxyalkanoate oligomers for reduction of hospital-acquired infections.

INTRODUCTION: The prevention and control of hospital-acquired infections remain a significant challenge worldwide, as textiles used in hospital wards are highly involved in transmission processes. This paper reports a new antibacterial medical fabric used to prepare hospital pillowcases, bottom sheets and quilt covers for controlling and reducing hospital-acquired infections. METHOD: The medical fabric was composed of blended yarns of staple polyester (PET) and degradable poly(3-hydroxybutyrate co-3-hydroxyvalerate) (PHBV)/polylactic acid (PLA) fibres, which were coated with polylactide oligomers (PLAO), which are environmentally friendly and safe antimicrobial agents with excellent thermal stability in high-temperature laundry. A clinical trial was conducted, with emphasis on the bacterial species that were closely related to the infection cases in the study hospital. RESULT: After 7 days of use, 94% of PET/PHBV/PLA-PLAO fabric retained <20 colony-forming units/100 cm2 of the total bacterial amount, meeting hygiene and cleanliness standards. CONCLUSION: This study demonstrates the potential of fabrics containing polyhydroxyalkanoate oligomers as highly effective, safe and long-lasting antimicrobial medical textiles that can effectively reduce the incidence of hospital-acquired infections.

Accuracy of machine learning in the preoperative identification of ovarian borderline tumors: a meta-analysis.

AIM: The objective of this study is to explore the diagnostic value of machine learning (ML) in borderline ovarian tumors through meta-analysis. METHODS: Pubmed, Embase, Web of Science, and Cochrane Library databases were comprehensively retrieved from database inception untill February 16, 2023. The Prediction Model Risk of Bias Assessment Tool (PROBAST) was adopted to evaluate the risk of bias in the original studies. Sub-group analyses of ML were conducted according to clinical features and radiomics features. We separately discussed the discriminative value of ML for borderline vs benign and borderline vs malignant tumors. RESULTS: Eighteen studies involving 12,778 subjects were included in our analysis. The modeling variables mainly consisted of radiomics features (n=13) and a small number of clinical features (n=5). When distinguishing between borderline and benign tumors, the ML model based on radiomic features achieved a c-index of 0.782 (95% CI: 0.732-0.831), sensitivity of 0.75 (95% CI: 0.67-0.82), and specificity of 0.75 (95% CI: 0.67-0.81) in the validation set. When distinguishing between borderline and malignant tumors, the ML model based on radiomic features achieved a c-index of 0.916 (95% CI: 0.891-0.940), sensitivity of 0.86 (95% CI: 0.78-0.91), and specificity of 0.88 (95% CI: 0.82-0.92) in the validation set. In addition, we analyzed the discriminatory ability of radiologists and found that their sensitivity was 0.26 (95% CI: 0.12-0.46) and specificity was 0.94 (95% CI: 0.90-0.97). CONCLUSIONS: ML has tremendous potential in the preoperative diagnosis and differentiation of borderline ovarian tumors and may be more accurate than radiologists in diagnosing and differentiating borderline ovarian tumors.

[Dental pulp stem cells in tooth regeneration: advancement and emerging directions].

Regenerating tissues similar to dental structure with normal function are putatively to be the aim in tooth regeneration filed. Currently, researchers preliminarily achieved tooth regeneration by applying dental pulp stem cells (DPSC) and stem cells from human exfoliated deciduous teeth (SHED). However, the regeneration efficiency remains unstable and needs further investigation. The development of single-cell RNA sequencing and organoid culture system provide potential of precise, targeted and controllable functional regeneration. This article reviews the current state of DPSC/SHED on tooth regeneration, and analyzes characteristics and hotspots of them, aiming to shed light on clinical translational application of stable and efficient tooth regeneration.

[Liver cancer treatment with mitochondrial homeostasis].

Systemic treatment, including molecular targeted therapy, immunotherapy, and chemotherapy, is an important means of achieving long-term survival in patients with intermediate-and advanced-stage liver cancer. However, some patients are insensitive to treatment and even develop drug resistance. Mitochondria are the center of cellular energy metabolism and, at the same time, are the priority targets for systemic therapy. Mitochondrial homeostasis plays an important role in the treatment of liver cancer. The relationship between the two advances is elucidated so as to provide better ideas for the clinical treatment of liver cancer.

Development of the Clinical pHysical rEsilience assEssment Scale (CHEES) in Chinese Older Adults.

BACKGROUND: Physical resilience is an emerging concept that describes an individual's capacity to recover from stressors. However, few instruments are currently available for assessing physical resilience. OBJECTIVE: To develop a scale to assess physical resilience in older adults. DESIGN: Development of a clinical scale. SETTING AND PARTICIPANTS: A total of 172 hospitalized older adults were recruited. MEASUREMENTS: This study comprised two stages. First, a pool of physical resilience scale items was created through a literature review, and the Delphi method was used to establish an initial scale. Second, the initial physical resilience scale was tested on hospitalized older adults. RESULTS: Five primary and 19 secondary items were identified after reviewing the literature. After two rounds of expert consultations, three primary and 16 secondary items were determined. The overall Cronbach's alpha for the scale was 0.760. Except for items N2, N4, N5, N8, and N14, Pearson's correlation between the scores of the remaining items and the total score ranged from 0.407 to 0.672. Except for items N2, N4, and N5, the corrected item-total correlation results ranged from 0.301 to 0.580, indicating good consistency between each item and the overall scale. Factor analysis showed that except for N7, the factor loadings of the remaining items were between 0.584 and 0.844. After expert discussions, items N2, N4, N7, and N14 were included in the scale, and items N5 and N8 were removed. CONCLUSION: A 14-item physical resilience scale, CHEES, was developed to assess physical resilience levels in older adults.

Hydroponic barley supplementation fed with high-protein diets improves the production performance of lactating dairy cows.

The study investigated the effects of dietary protein level and the inclusion of hydroponic barley sprouts (HB) on lactation performance, blood biochemistry and N use efficiency in mid-lactation dairy cows. Treatments were arranged in a 2 × 2 factorial design with 2 CP levels (16.8% and 15.5% of DM), with HB (4.8% of DM, replacing 4.3% of alfalfa hay and 0.5% of distillers dried grains with solubles [DDGS]) or without HB. Forty-eight multiparous Holstein dairy cows (146 ± 15 DIM, 40 ± 5 kg/d of milk) were randomly allocated to 1 of 4 diets: high-protein diet (16.8% CP, HP), HP diet with HB (HP+HB), low-protein diet (15.5% CP, LP), or LP diet with HB (LP+HB). An interaction between CP × HB on DMI was detected, with DMI being unaffected by HB inclusion in cows fed the high-protein diets, but was lower in cows fed HB when the low-protein diet was fed. A CP × HB interaction was also observed on milk and milk protein yield, which was higher in cows fed HB with HP, but not LP. Inclusion of HB also tended to reduce milk fat content, and feeding HP resulted in a higher milk protein and MUN content, but lower milk lactose content. Feed efficiency was increased by feeding HP or HB diets, whereas N use efficiency was higher for cows fed LP or HB diets. There was an interaction on the apparent total-tract digestibility of DM and CP, which was higher when HB was fed along with HP, but reduced when fed with LP, whereas the digestibility of ADF was increased by feeding low-protein diets. In conclusion, feeding a low-protein diet had no adverse effect on cow performance, while feeding HB improved milk and milk component yield, and N efficiency when fed with a high-CP diet, but compromised cow performance with a low-CP diet.