[Exosome derived from human adipose-derived mesenchymal stem cells prevented bone loss induced by estrogen deficiency]

OBJECTIVE

To investigate the effect of human adipose-derived mesenchymal stem cells (hASCs) exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) extracted from osteoporotic mice, and to evaluate the effect of hASCs exosomes on preventing bone loss induced by estrogen deficiency.

METHODS

hASCs exosomes were extracted by ultracentrifugation. The osteoporotic mice were established by bilateral ovariectomy (OVX). BMSCs were isolated from osteo-porotic mice and cultured for further analysis. In the experimental group, these BMSCs were exposed to an osteogenic induction medium supplemented with hASCs exosomes to evaluate their potential effects on osteogenesis. In contrast, the control group was treated with the same osteogenic induction medium, but without the addition of hASCs exosomes, to serve as a baseline comparison for the study. To comprehensively assess the osteogenic differentiation of BMSCs influenced by hASCs exosomes, alkaline phosphatase (ALP) staining, ALP activity quantitative analysis and quantitative reverse transcription polymerase chain reaction (qPCR) were performed. These evaluations provided critical insights into the role of hASCs exosomes in promoting osteoblast differentiation and bone formation in osteoporotic conditions. The fluorescence labeled hASCs exosomes were injected via the tail vein to observe the biodistribution of exosomes. Two weeks after OVX, the mice were divided into three groups: The experimental group consisted of estrogen-deficient mice receiving hASCs exosome injections; the negative control group consisted of estrogen-deficient mice receiving phosphate-buffered saline (PBS) injections; and the positive control group consisted of mice that underwent Sham surgery and received PBS injections.The injections were administered once every 3 days, for a total of 8 injections. Afterward, the femurs were collected from the mice, and micro-computed tomography (micro-CT) was performed to measure bone mineral density and conduct bone morphometric analysis.

RESULTS

hASCs exosomes were successfully extracted using ultracentrifugation. After the induction by hASCs exosomes, ALP staining and ALP activity in the BMSCs extracted from osteoporotic mice were significantly enhanced, the expression of osteogenesis related genes in BMSCs were significantly up-regulated. More trabecular bone and higher bone mineral density were observed in estrogen-deficient mice injected with hASCs exosomes compared with estrogen-deficient mice injected with PBS, and there was no significant decrease in bone mineral density compared with the Sham operation group.

CONCLUSION

hASCs exosomes promoted the osteogenic differentiation of BMSCs extracted from osteoporotic mice. hASCs exosomes prevented bone loss induced by estrogen deficiency.

[Value of artificial intelligence in the improvement of diagnostic consistency of radiology residents]

OBJECTIVE

To explore the value of artificial intelligence (AI) in improving the detection rate of traumatic rib fractures by radiologist residents and the consistency among different readers.

METHODS

Chest CT images of 393 patients with acute trauma from China-Japan Union Hospital of Jilin University (hospital 02) and Shanghai Ninth People' s Hospital (hospital 03) were collected in this research. The consensus achieved by three radiology experts was regarded as the reference standard. All the images assigned to three hospitals: Peking University First Hospital (hospital 01), hospital 02 and hospital 03, and were then randomly divided into two groups (group A and group B: group A included 197 patients, and group B included 196 patients). Each group was read by one radiologist resident from each hospital for rib fracture detection. Each case was read twice by the same radiologist, with and without the assistance of the AI ["radiologist-only" reading and "radiologist + AI" reading]. The detection rates of different types of rib fractures (displaced fractures and occult fractures) were compared between "radiologist-only" reading and "radiologist + AI" reading. The consistencies of different radiologists with different reading methods were evaluated.

RESULTS

The detection rates of displaced rib fractures and occult rib fractures by "radiologist + AI" reading were significantly higher than those read by "radiologist-only" reading (94.56% vs. 78.40%, 76.60% vs. 49.42%, P < 0.001). For "radiologist-only reading", the Kappa coefficients of the radiologists between hospital 01 and hospital 03 were slightly greater than 0.4 (indicating moderate consistency), the coefficients of the radiologists between hospital 01/hospital 02 and hospital 02/hospital 03 were less than 0.4 (indicating poor consistency). The Phi coefficients of the radiologists among different hospitals were all less than 0.6 (indicating moderate correlation). With "radiologist + AI" reading, the Kappa and Phi coefficient among the radiologists in dif-ferent hospitals were greater than or equal to 0.6 (indicating good consistency and correlation).

CONCLUSION

AI software can be used to automatically detect suspected rib fracture lesions, which helps to improve the detection rate of fracture lesions and the consistency among different readers.

[Changes in shape and signal intensity of high intensity zone in lumbar intervertebral discs on magnetic resonance images: a longitudinal study]

OBJECTIVE

To investigate changes over time in the shape and signal intensity of high intensity zone (HIZ) in the lumbar intervertebral discs on magnetic resonance images in patients with low back pain.

METHODS

The imaging data were collected from 27 patients with low back pain, who underwent lumbar magnetic resonance (MR) imaging examinations that identified HIZ lesions and received follow-up MR examinations at least 1.5 years later over the period from January 2009 to January 2017. The initial and follow-up MR T2WI images of the patients were read by two experienced radiologists to categorize the changes in the shape of the HIZ lesions into enlarged, unchanged, shrunk, and disappeared. The volume and signal/cerebrospinal fluid signal intensity (T2/CSF) ratio of the HIZ were measured on sagittal MR images using ImageJ software.

RESULTS

Of the 43 HIZ lesions found in the initial examinations, 22 (51.2%) remained unchanged in the follow-up examinations, 10 (21.3%) were enlarged, 9 (20.9%) shrank, and 2 (23.3%) disappeared. The follow-up examinations revealed 4 new HIZ lesions in the intervertebral discs. The volumes of these lesions did not vary significantly in the follow-up examinations (P=0.653), but the T2/CSF ratio was significantly higher in the follow-up than in the initial examinations (P=0.043).

CONCLUSIONS

After observation for an average of 3 years and 3 months, most of the HIZ lesions in the lumbar intervertebral discs of the patients with low back pain remained stable in shape, but their signal intensity on MR images increased.

[Clinical analysis of cases of otogenic sigmoid sinus thrombosis in children]

Objective:To analyze the clinical characteristics of middle ear mastoiditis combined with sigmoid sinus thrombophlebitis in children. Methods:Author retrospectively analyzed the clinical data of 6 children with middle ear mastoiditis combined with sigmoid sinus thrombophlebitis who were hospitalized in the Department of Infectious Diseases and Department of Neurology with first diagnosis of fever/headache, and subsequently underwent middle ear mastoidectomy in our department. All patients underwent comprehensive otoscopic, audiologic, imaging, and pathogenetic examinations. Clinical manifestations, pathogenetic features, treatment methods and prognosis were summarized, and the follow-up period was 3-6 months. Results:All 6 cases were first diagnosed with intracranial complications such as fever and headache in the internal medicine department. Within one month, all patients developed ear symptoms including pain, discharge, and hearing loss. Audiologic examination revealed conductive hearing loss in five cases and total deafness in one case. MRI, MRV and MRA examinations suggested that there were 6 cases of middle ear infection combined with thrombophlebitis of the ethmoid sinus, of which 3 cases had thrombus in the ethmoid sinus. 6 cases received surgical treatments: 2 cases of radical mastoidectomy+grommet Insertion, and 4 cases of radical mastoidectomy. Pathogenetic examination identified Streptococcus pneumoniae in three cases, Pseudomonas aeruginosa in one case, Enterobacter cloacae complex in one case, and no pathogens were detected in one case. Postoperative pathology was inflammatory granulation in all 6 cases. Follow-up was 3-6 months with no recurrence of intracranial and middle ear lesions on regular review. Conclusion:Children with recurrent fever, headache, and a recent history of acute and chronic otitis media should be evaluated for the possibility of sigmoid sinus thrombophlebitis, and imaging tests should be performed in a timely manner to clarify the diagnosis. Once diagnosed, surgery to remove the lesions around the ethmoid sinus, smooth drainage combined with antibiotic therapy is the most direct and effective treatment, and anticoagulation therapy is given when necessary. Timely diagnosis, multidisciplinary collaboration, and accurate timing of the management of primary foci and comorbidities are crucial to the treatment of the disease.

[Long-term auditory monitoring in children with Alport syndrome based on different degrees of renal injury]

Objective:To investigate long-term auditory changes and characteristics of Alport syndrome（AS） patients with different degrees of renal injury. Methods:Retrospectively analyzing clinical data of patients diagnosed AS from January 2007 to September 2022, including renal pathology, genetic detection and hearing examination. A long-term follow-up focusing on hearing and renal function was conducted. Results:This study included 70 AS patients, of which 33（25 males, 8 females, aged 3.4-27.8 years） were followed up, resulting in a loss rate of 52.9%.The follow-up period ranged from 1.1to 15.8 years, with 16 patients followed-up for over 10 years. During the follow-up, 10 patients presenting with hearing abnormalities at the time of diagnosis of AS had progressive hearing loss, and 3 patients with new hearing abnormalities were followed up, which appeared at 5-6 years of disease course. All of which were sensorineural deafness. While only 3 patients with hearing abnormalities among 13 patients received hearing aid intervention. Of these patients,7 developed end-stage renal disease（ESRD）, predominantly males （6/7）. The rate of long-term hearing loss was significantly different between ESRD group and non-ESRD group（P=0.013）. There was no correlation between the progression of renal disease and long-term hearing level（P>0.05）. kidney biopsies from 28 patients revealed varying degrees of podocyte lesion and uneven thickness of basement membrane. The severity of podocyte lesion was correlated with the rate of long-term hearing loss（P=0.048）, and there was no correlation with the severity of hearing loss（P>0.05）. Among 11 cases, theCOL4A5mutationwas most common （8 out of 11）, but there was no significant correlation between the mutation type and hearing phenotype（P>0.05）. Conclusion:AS patients exhibit progressive hearing loss with significant heterogeneity over the long-term.. THearing loss is more likely to occur 5-6 years into the disease course. Hearing abnormalities are closely related to renal disease status, kidney tissue pathology, and gene mutations, emphasizing the need for vigilant long-term hearing follow-up and early intervention.