BACKGROUNDLittle is known about the value of (31)P-magnetic resonance spectroscopy ((31)P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle. We aimed to evaluate the value of a (31)P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats, and the correlation between (31)P-MRS and histological changes.

METHODSSixty male Sprague-Dawley rats were randomly assigned to control, half-exhaustive, and exhaustive exercise groups. (31)P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi, PCr, and β-ATP. The Pi/PCr, Pi/β-ATP, PCr/β-ATP, and PCr/(PCr+Pi) were calculated and pH measured. Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of (31)P-MRS in identifying and distinguishing the three groups. HE staining, electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard. The correlation between (31)P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.

RESULTSPi, PCr, Pi/PCr, and PCr/(PCr+Pi) showed statistically significant intergroup differences (P < 0.05). AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.905, 0.848, 0.930, and 0.930 for the control and half-exhaustive groups, while sensitivity and specificity were 90%/85%, 95%/55%, 95%/80%, and 90%/85%, respectively. The AUCs of Pi, PCr, Pi/PCr and PCr/(PCr+Pi) were 0.995, 0.980, 1.000, and 1.000 for the control and exhaustive groups, while sensitivity and specificity were 95%/90%, 100%/90%, 100%/95%, and 100%/95%, respectively. The AUCs of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were 0.735, 0.865, 0.903, and 0.903 for the half-exhaustive and exhaustive groups, while sensitivity and specificity were 80%/60%, 90%/75%, 95%/65%, and 95%/70%, respectively. In the half-exhaustive group, some muscle fibers exhibited edema in HE staining, and the unclear Z-discs and the mitochondria with vacuolar degeneration under electron microscopy. Compared with the half-exhaustive group, muscle fiber edema was increased in the exhaustive group, and the Z-discs were broken and the mitochondria exhibited marked vacuolar degeneration under electron microscopy. There were significant difference in A values of desmin staining in the right vastus lateralis among the control, half-exhaustive, and exhaustive groups with 0.58 ± 0.06, 0.30 ± 0.04, and 0.21 ± 0.02, respectively (P < 0.05). Histological examination also showed injury-induced changes in the vastus lateralis among the different intensities groups. Statistically a moderate correlation between (31)P-MRS and desmin was observed, the correlation coefficients of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) were -0.706, 0.709, -0.726, and 0.791, respectively (P < 0.01).

CONCLUSIONS(31)P-MRS can effectively reflect the changes in energy metabolism in the skeletal muscle after a single bout of acute exhaustive swimming in rats. Based on the significant correlation between (31)P-MRS parameters and histological changes, the changes of Pi, PCr, Pi/PCr, and PCr/(PCr+Pi) can indirectly reflect the degree of exercise-induced injury.

Animals ; Energy Metabolism ; physiology ; Magnetic Resonance Spectroscopy ; methods ; Male ; Physical Conditioning, Animal ; physiology ; Quadriceps Muscle ; metabolism ; Rats ; Rats, Sprague-Dawley

The present research was to study the biocompatibility of a composite of hydroxyapatite (HA), carbon fiber (CF) and polyetheretherket-one (PEEK) by co-culturing with the osteoblasts in vitro. Cell relative growth (RGR) was used as a quantitative assessment for cytotoxicity of the biomaterials by CCK-8. The proliferation index of the co-cultured cells and ALP activity was measured to study the effect of PEEK-HA-CF composites. Morphological properties of the osteoblast cells in vitro were observed by scanning electro-microscopy (SEM). The PEEK-HA-CF materials have no cytotoxicity to osteoblasts. The proliferation index of PEEK-HA-CF was higher than that of Ti alloy group, but these was no significant difference compared to that of control group. The ALP activity was the highest on PEEK-HA-CF composites surface after 7 days. The osteoblast cells co-cultured with the PEEK-HA-CF composite were adhered well to the biomaterial as observed under the SEM. The results suggested that the PEEK-HA-CF composites had good biocompatibility in vitro and might be a novel orthopedic implanted material.
Alkaline Phosphatase ; metabolism ; Animals ; Biocompatible Materials ; Carbon ; chemistry ; Cell Proliferation ; drug effects ; Cells, Cultured ; Durapatite ; chemistry ; Ketones ; chemistry ; Orthopedics ; Osteoblasts ; chemistry ; Polyethylene Glycols ; chemistry ; Prostheses and Implants ; Rats

Objective To analyze the influencing factors of peritoneal dialysis associated peritonitis(PDAP)and the distribution characteristics of pathogenic bacteria.Methods The clinical data of 257 patients who underwent peritoneal dialysis(PD)and regular follow-up in Meizhou People's Hospital from January 2012 to October 2022 were retrospectively analyzed.According to the occurrence of PDAP,the patients were divided into the PDAP group(n=102)and the non-PDAP group(n=155).The exhaled liquid(5-10 mL)was extracted with a sterile syringe,and the pathogen was identified by blood culture method.General data such as gender,age,primary disease,education level,whether complicated with hypertension/diabetes/cardiovascular diseases,whether keeping pets or poultry,body mass index(BMI)and dialysis duration were collected.Fasting elbow venous blood was drawn in the morning of the next day after diagnosis,the levels of hemoglobin(Hb),albumin(ALB),serum potassium,serum phosphorus,and serum calcium were detected.The estimated glomerular filtration rate(eGFR)and urea clearance index(UCI)were recorded.Multivariate logistic regression was used to analyze the risk factors of PDAP in PD patients.Results There were 217 cases of PDAP in 102 patients with PDAP,and 124 cases(57.14％)were positive for pathogen culture.A total of 127 pathogenic bacteria were isolated,including 84 Gram-positive strains(66.14％),39 Gram-negative strains(30.71％)and 4 Fungi strains(3.15％).Among the 84 strains of Gram-positive bacteria,there were 25 strains of staphylococcus epidermidis(29.76％),17 strains of staphylococcus aureus(20.24％),12 strains of staphylo-coccus haemolyticus(14.29％),8 strains of staphylococcus warneri(9.52％),10 strains of streptococcus salivarius(11.90％),5 strains of streptococcus sanguis(5.95％),and 7 other strains(8.33％).Among the 39 strains of Gram-nega-tive bacteria,there were 20 strains of escherichia coli(51.28％),6 strains of pseudomonas aeruginosa(15.38％),6 strains of acinetobacter baumannii(15.38％),5 strains of klebsiella pneumoniae(12.82％),and 2 strains of enterobacter cloacae(5.13％).Among the 4 strains of Fungi,there were 3 strains of near-smooth candida(75.00％)and 1 strain of candida glabrata(25.00％).There was no significant difference in gender,age,primary disease,education level,BMI,and the propor-tion of comorbidities with hypertension,diabetes and cardiovascular diseases between the PDAP and non-PDAP groups(P＞0.05).The proportion of patients keeping pets or poultry in the PDAP group was higher than that in the non-PDAP group,and the dialysis duration was longer than that in the non-PDAP group(P＜0.05).There was no significant difference in serum phosphorus,serum calcium,eGFR and UCI between the PDAP and non-PDAP groups(P＞0.05).The levels of Hb,ALB and serum potassium in the PDAP group were significantly lower than those in the non-PDAP group(P＜0.05).Logistic regression analysis showed that keeping pets or poultry and long dialysis duration were risk factors for PDAP in PD patients(P＜0.05).High Hb and ALB levels were protective factors for PDAP in PD patients(P＜0.05).There was no correlation between serum potassium and PDAP in PD patients(P＞0.05).Conclusion Gram-positive bacteria are the main pathogenic bacteria of PDAP,among which staphylococcus epidermidis is the predominant one.Keeping pets or poultry and long dialysis duration are risk factors for PDAP,while high Hb and ALB levels are protective factors for PDAP in PD patients.

Objective Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo.Methods Fluorescent microspheres (100 nm, 3 μm, and 10 μm) were given once at a dose of 200 mg/(kg·body weight). The fluorescence intensity (FI) in observed organs was measured using the IVIS Spectrum at 0.5, 1, 2, and 4 h after administration. Histopathology was performed to corroborate these findings.Results In the 100 nm group, the FI of the stomach and small intestine were highest at 0.5 h, and the FI of the large intestine, excrement, lung, kidney, liver, and skeletal muscles were highest at 4 h compared with the control group (P < 0.05). In the 3 μm group, the FI only increased in the lung at 2 h (P < 0.05). In the 10 μm group, the FI increased in the large intestine and excrement at 2 h, and in the kidney at 4 h (P < 0.05). The presence of nano-/microplastics in tissues was further verified by histopathology. The peak time of nanoplastic absorption in blood was confirmed.Conclusion Nanoplastics translocated rapidly to observed organs/tissues through blood circulation;however, only small amounts of MPs could penetrate the organs.

Objective To establish the spatial course of distal tubule and afferent arterioles after macula densa, and to locate and detect the proteins in the adjacent parts by using three-dimensional visualization technology of microstructure. Methods C57 BL/6J mice were fixed by perfusion and embedded in epon 812. Tissue blocks were cut perpendicular to the longitudinal axis of the kidney. And a total of 720, 2. 5 μm-thick consecutive sections were obtained from the renal capsule to the outer stripe of the renal outer medulla. After aligning the digital microscopic images through computer registration procedures, the tubules and vessels were traced by 3D reconstruction program edited by C Language. Selecting the tissue sections of the contact site and applying the improved immunoperoxidase staining method to detect H

Child ; Consensus ; Drugs, Chinese Herbal ; Humans ; Medicine, Chinese Traditional ; Respiratory System

BACKGROUND: Pneumonia-like primary pulmonary lymphoma (PPL) was commonly misdiagnosed as infectious pneumonia, leading to delayed treatment. The purpose of this study was to establish a computed tomography (CT)-based radiomics model to differentiate pneumonia-like PPL from infectious pneumonia. METHODS: In this retrospective study, 79 patients with pneumonia-like PPL and 176 patients with infectious pneumonia from 12 medical centers were enrolled. Patients from center 1 to center 7 were assigned to the training or validation cohort, and the remaining patients from other centers were used as the external test cohort. Radiomics features were extracted from CT images. A three-step procedure was applied for radiomics feature selection and radiomics signature building, including the inter- and intra-class correlation coefficients (ICCs), a one-way analysis of variance (ANOVA), and least absolute shrinkage and selection operator (LASSO). Univariate and multivariate analyses were used to identify the significant clinicoradiological variables and construct a clinical factor model. Two radiologists reviewed the CT images for the external test set. Performance of the radiomics model, clinical factor model, and each radiologist were assessed by receiver operating characteristic, and area under the curve (AUC) was compared. RESULTS: A total of 144 patients (44 with pneumonia-like PPL and 100 infectious pneumonia) were in the training cohort, 38 patients (12 with pneumonia-like PPL and 26 infectious pneumonia) were in the validation cohort, and 73 patients (23 with pneumonia-like PPL and 50 infectious pneumonia) were in the external test cohort. Twenty-three radiomics features were selected to build the radiomics model, which yielded AUCs of 0.95 (95% confidence interval [CI]: 0.94-0.99), 0.93 (95% CI: 0.85-0.98), and 0.94 (95% CI: 0.87-0.99) in the training, validation, and external test cohort, respectively. The AUCs for the two readers and clinical factor model were 0.74 (95% CI: 0.63-0.83), 0.72 (95% CI: 0.62-0.82), and 0.73 (95% CI: 0.62-0.84) in the external test cohort, respectively. The radiomics model outperformed both the readers' interpretation and clinical factor model ( P <0.05). CONCLUSIONS The CT-based radiomics model may provide an effective and non-invasive tool to differentiate pneumonia-like PPL from infectious pneumonia, which might provide assistance for clinicians in tailoring precise therapy.
Humans ; Retrospective Studies ; Pneumonia/diagnostic imaging* ; Analysis of Variance ; Tomography, X-Ray Computed ; Lymphoma/diagnostic imaging*