Thymocyte migration and emigration.

Hematopoietic precursors (HPCs) entering into the thymus undergo a sequential process leading to the generation of a variety of T cell subsets. This developmental odyssey unfolds in distinct stages within the thymic cortex and medulla, shaping the landscape of T cell receptor (TCR) expression and guiding thymocytes through positive and negative selection. Initially, early thymic progenitors (ETPs) take residence in the thymic cortex, where thymocytes begin to express their TCR and undergo positive selection. Subsequently, thymocytes transition to the thymic medulla, where they undergo negative selection. Both murine and human thymocyte development can be broadly classified into distinct stages based on the expression of CD4 and CD8 coreceptors, resulting in categorizations as double negative (DN), double positive (DP) or single positive (SP) cells. Thymocyte migration to the appropriate thymic microenvironment at the right differentiation stage is pivotal for the development and the proper functioning of T cells, which is critical for adaptive immune responses. The journey of lymphoid progenitor cells into the T cell developmental pathway hinges on an ongoing dialogue between the differentiating cell and the signals emanating from the thymus niche. Herein, we review the contribution of the key factors mentioned above for the localization, migration and emigration of thymocytes.

Postoperative discal pseudocyst and its similarities to discal cyst: A case report.

BACKGROUND: Postoperative discal pseudocyst (PDP) is a rare condition that presents after surgery for lumbar disc herniation. Due to the lack of information, the diagnosis and treatment of PDP remain controversial. Herein, we report a PDP case that occurred following percutaneous endoscopic lumbar discectomy and received conservative treatment. Additionally, we review all the published literature regarding PDP and propose our hypothesis regarding PDP pathology. CASE SUMMARY: A 23-year-old man presented with a relapse of low back pain and numbness in his left lower extremity after undergoing percutaneous endoscopic lumbar discectomy for lumbar disc herniation. Repeat magnetic resonance imaging demonstrated a cystic lesion at the surgical site with communication with the inner disc. The patient was diagnosed as having PDP. The patient received conservative treatment, which resulted in rapid improvement and spontaneous regression of the lesion, and had a favorable outcome in follow-up. CONCLUSION: PDP and discal cyst (DC) exhibit similarities in both histological and epidemiological characteristics, which indicates the same pathological origin of PDP and DC. The iatrogenic annular injury during discectomy might accelerate the pathological progression of DC. For patients with mild to moderate symptoms, conservative treatment can lead to great improvement, even inducing spontaneous regression. However, surgical cystectomy is necessary in patients with neurological deficits and where conservative treatment is ineffective.

Malignant solitary fibrous tumor of the greater omentum: A case report and review of literature.

BACKGROUND: Malignant solitary fibrous tumors (SFTs) account for 15%-20% of all SFTs, and malignant SFTs arising from the greater omentum are extremely rare. Most malignant SFTs of the greater omentum are diagnosed via pathological examinations after surgery. In this study, we report a case of malignant omental SFT and review the published literature on this rare malignancy. CASE SUMMARY: A 64-year-old female presented with an abdominal mass, and underwent exploratory surgery, during which a huge tumor originating from the greater omentum and intraperitoneal implants were identified and resected. The results of the pathological examination, immunohistochemistry staining, and gene sequencing led to the diagnosis of malignant SFT of the greater omentum. The patient died one and a half years later due to tumor recurrence and metastasis. CONCLUSION: This is the first report of the application of gene sequencing in the diagnosis of malignant SFTs of the greater omentum.

Low-viscosity sodium alginate combined with TiO2 nanoparticles for improving neuroblastoma treatment.

Titanium dioxide (TiO2) nanoparticles have been explored to prevent various cancer developments but it may cause oxidation, inflammation and high cytotoxicity. Alginate has nontoxic, anti-inflammatory, and antioxidant effects. We aimed to explore the effects of alginate-TiO2 temozolomide (TMZ) nanoparticles on neuroblastoma. A neuroblastoma model was established with neuroblastoma cells and alginate-TiO2 TMZ nanoparticles were made by spraying low-viscosity sodium alginate (250-360 kDa). The morphology of nanoparticles was observed via scanning electron microscope (SEM). The crystallinity values were analyzed via X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic study. Neuroblastoma mice were treated with saline solution, TMZ, TiO2-TMZ and alginate-TiO2-TMZ nanoparticles. Anti-oxidant, anti-inflammatory, and anti-tumor properties and the mouse survival rates were measured. The spectrometric profiles of alginate-TiO2 were consistent with those of TiO2 and alginate. Alginate-TiO2 TMZ nanoparticles had higher cytotoxicity toward neuroblastoma cells and less inhibitory activity toward normal neuronal cells. The combined nanoparticles increased antioxidant, anti-inflammatory and antitumor activities and prolonged the survival time of the neuroblastoma model (P < 0.05). On the other hand, Alginate-TiO2 TMZ nanoparticles reduced the levels of mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB). The combined nanoparticles improved neuroblastoma treatment by affecting NF-κB and MAPK signals.

Wandering spleen with splenic torsion in a toddler: A case report and literature review.

RATIONALE: Wandering spleen (WS) is a rare clinical entity characterized by splenic hypermobility caused by absent or abnormal laxity of the suspensory ligaments, which fix the spleen in its normal position. Due to abnormal attachment, the spleen is predisposed to torsion and a series of complications. Pediatric WS is mostly reported in children aged <10 years, especially among infants aged <1 year; it is uncommon among toddlers between 1 and 3 years. To the authors' knowledge, only seven cases of WS have been described previously. Herein, we present the case of a 3-year-old toddler with WS and splenic torsion. PATIENT CONCERNS: A 3-year-old boy was presented to the pediatric emergency room with a 2-day history of abdominal pain and vomiting. The ultrasonographic examination revealed a mass in the left upper abdomen cavity and absence of spleen in its normal position. Computed tomography showed an enlarged displaced spleen occupying the left abdomen cavity with an elongated splenic vascular pedicle (whirl sign), suggesting splenic torsion. DIAGNOSES: The patient was diagnosed that had WS and splenomegaly, with or without complications due to splenic torsion. INTERVENTIONS: The patient underwent emergency laparotomy and splenectomy due to nonviability after detorsion. OUTCOMES: The postoperative course was uneventful, and the patient was discharged on the 7th day postoperatively without complications. The patient had favorable outcome over a 1-year follow-up. LESSONS: Herein, we reported the case of a toddler with WS with splenic torsion. Moreover, after reviewing relevant studies in literature, we presented our findings on the diagnosis and treatment of toddlers with WS. Toddlers with WS are characterized by acute abdominal pain, unclear history description, examination restrictions, and high rates of life-threatening complications. High level of suspicion, careful physical examination, detailed history collection, and objective investigation are crucial in the management of toddlers with WS.

Human Thymic Involution and Aging in Humanized Mice.

Thymic involution is an important factor leading to the aging of the immune system. Most of what we know regarding thymic aging comes from mouse models, and the nature of the thymic aging process in humans remains largely unexplored due to the lack of a model system that permits longitudinal studies of human thymic involution. In this study, we sought to explore the potential to examine human thymic involution in humanized mice, constructed by transplantation of fetal human thymus and CD34+ hematopoietic stem/progenitor cells into immunodeficient mice. In these humanized mice, the human thymic graft first underwent acute recoverable involution caused presumably by transplantation stress, followed by an age-related chronic form of involution. Although both the early recoverable and later age-related thymic involution were associated with a decrease in thymic epithelial cells and recent thymic emigrants, only the latter was associated with an increase in adipose tissue mass in the thymus. Furthermore, human thymic grafts showed a dramatic reduction in FOXN1 and AIRE expression by 10 weeks post-transplantation. This study indicates that human thymus retains its intrinsic mechanisms of aging and susceptibility to stress-induced involution when transplanted into immunodeficient mice, offering a potentially useful in vivo model to study human thymic involution and to test therapeutic interventions.

Completely ossified thoracic intradural meningioma in an elderly patient: A case report and literature review.

RATIONALE: Spinal meningioma is the second most common spinal neoplasm that commonly occurs in middle-aged women. As a rare histological variation of meningioma, completely ossified meningioma (OSM) and its standard surgical strategies have been reported. However, the surgical outcomes of elderly OSM cases (age >70) are less investigated. Herein, we intend to present an elderly OSM case and review the elderly OSM cases in published literatures. PATIENT CONCERNS: An 85-year-old female presented with 10-year history of back pain and developed radiating pain on her left lower extremity within the last 2 weeks. DIAGNOSES: A magnetic resonance imaging scan revealed an intradural tumor at the T11 level. A computed tomography scan demonstrated that the mass was completely ossified and had distinct borders (D-F). In a dynamic contrast-enhanced magnetic resonance imaging scan, the mass presented as a lateral intradural extramedullary tumor with abundant blood supply (). INTERVENTIONS: The patient underwent en bloc intradural tumorectomy via posterior approach. OUTCOMES: After surgery, the patient's pain was relieved. However, the patient spent another 3 weeks in hospital due to a series of post-surgery complications, including hypostatic pneumonia, pulmonary heart failure, hydrothorax in both thoracic cavities, hypoproteinemia, and deep venous thrombosis on both of her legs. The complications recovered after 3-weeks treatment. In 1-year follow up, no additional symptom was found and the patient was recurrence free. LESSONS: Our report indicated that the surgical outcome can be satisfying in elderly OSM patients, while the post-operative complications frequently occur due to the poor physical condition of elderly patients. As a result, treatment of peri-operative complications of elderly OSM patients also deserves greater attention along with surgical resection.

Mid-lumbar traumatic spondyloptosis without neurological deficit: A case report and literature review.

INTRODUCTION: Spondyloptosis is a form of vertebral dislocation and the most advanced form of spondylolisthesis. Traumatic spondyloptosis is usually caused by high-energy impact and results in unstable spine deformity and spinal canal deformation, which lead to severe spinal cord injury. Traumatic spondyloptosis is mostly reported in the lumbo-sacral junction, while it is rarely documented in mid-lumbar segments. To the best of the authors' knowledge, only 16 cases of mid-lumbar spondyloptosis have been described previously. Herein, we present a L3 to L4 spondyloptosis case that did not involve neurological deficit. PATIENT CONCERNS: A 42-year-old man presented to the emergency department after an accident involving a fall. The patient developed severe back pain and spinal deformity, while his neurologic function remained intact. Radiological examinations indicated complete posterior vertebral dislocation at L3 to L4 and a fracture at the bilateral pelvic ischial tuberosity without major vessel injury or severe dura sac compression. DIAGNOSES: L3 to L4 complete vertebral dislocation, pelvic ischial tuberosity fracture. INTERVENTIONS: For treatment, the patient underwent fracture reduction, L3 to L4 intervertebral fusion, and internal fixation 7 days post-injury. OUTCOMES: Postoperative digital radiography showed the correction of the spinal deformity. The patient was pain-free and fully rehabilitated 3 months after the surgery. At the 1-year follow-up, the patient was completely asymptomatic and had achieved normal alignment. CONCLUSIONS: We reported an L3 to L4 traumatic spondyloptosis case that involved intact neurology, which is the first-ever reported mid-lumbar spondyloptosis case that involved complete posterior column and neural sparing. For the treatment of traumatic spondyloptosis without neurological deficit, restoring stability and preventing secondary cord injury should be taken into consideration.

A case report of May-Thurner syndrome induced by anterior lumbar disc herniation: Novel treatment with radiofrequency thermocoagulation.

RATIONALE: Lumbar degeneration-related May-Thurner syndrome (dMTS) is characterized by venous compression induced by degenerated lower lumbar structures. Treatment strategies for May-Thurner syndrome (MTS) include clearing the thrombus and correcting venous compression. Despite having different etiological factors from other MTS types, treatments for dMTS are similar, including endovascular angioplasty and continuous anticoagulation therapies. Thus, a particular treatment was designed herein to focus on compressive lumbar structures instead of intravenous management. PATIENT CONCERNS: A 59-year-old female patient with dMTS, which was induced by inferior vena cava (IVC) stenosis compressed by L4-5 anterior disc herniation. DIAGNOSIS: The patient was diagnosed with IVC stenosis and L4-5 lumbar disc herniation based on abdominal computed tomography, ultrasound, and lumbar magnetic resonance imaging findings. INTERVENTIONS: Radiofrequency thermocoagulation (RF) was applied to the patient to decrease the compression caused by anterior disc herniation. OUTCOMES: After surgery, the patient's swelling started to improve within 5 hours and completely diminished after 48 hours. Postsurgical abdominal ultrasound showed that her IVC patency increased by 20%. On follow-up, her leg symptoms did not recur at 12 months after surgery. LESSONS: We provided a novel idea in the treatment of dMTS, in which we shifted the treatment focus from endovascular patency restoration to extravascular decompression. Our case proved that RF was effective in treating dMTS, which is a complementary treatment modality to angioplasty.

Percutaneous endoscopic thoracic discectomy via posterolateral approach: A case report of migrated thoracic disc herniation.

RATIONALE: Minimally invasive surgeries for thoracic disc herniation (TDH) evolved rapidly in recent years, and multiple approaches have been put forward. Thoracic discectomy via percutaneous spine endoscopy (PSE) is inadequately documented because of the low prevalence of TDH and the high difficulty of thoracic spine endoscopy techniques. Herein, we present a TDH case who underwent percutaneous endoscopic thoracic discectomy. PATIENT CONCERNS: A 28-year-old male suffered backpain and partial paralysis in lower extremities. DIAGNOSES: Magnet resonance imaging demonstrated T11-12 TDH, with cranially migrated disc fragment. INTERVENTIONS: The patient underwent percutaneous endoscopic thoracic discectomy via posterolateral approach with the assistance of endoscopic reamer in the procedure of foramino-laminaplasty. OUTCOMES: The patient's muscle force improved immediately, and the backpain relieved after 5 days post-surgery. In the 6-month follow-up, he had normal muscle force without paresthesia in lower limbs. LESSONS: The innovative design of endoscopic reamer provides effective plasty and access establishment with lower risk and difficulty, which ensures the vision and the operating space of the procedure of decompression. With this technique, the indications of thoracic PSE were broadened to both ventral and dorsal thoracic stenosis.

Recurrent lumbar disc herniation recurrence after percutaneous endoscopic lumbar discectomy: A case report.

RATIONALE: Lumbar disc herniation (LDH) is a degenerative disease and affects human health. Although percutaneous endoscopic lumbar discectomy (PELD) can redeem the living quality of patient with LDH rapidly, it appears weak to limit the recurrence rate of LDH. PATIENT CONCERNS: A 52-year-old male suffered lower back pain and lower limb paralysis for 20 years. However, conservative treatment could not relieve above-mentioned symptoms after doing heavy labor. DIAGNOSES: Computed tomography (CT) revealed a disc fragment had migrated to the inferior edge of the L5 pedicle. Magnetic resonance imaging (MRI) demonstrated a type 2 Modic change (MC) at L5 and spinal canal stenosis at L4-L5. Based on these findings, the patient was diagnosed with L4-L5 disc herniation and secondary lumbar stenosis. INTERVENTIONS: The patient underwent surgery twice for PELD at L4-L5 in 1 month. Symptoms were not improved effectively until the conventional posterior discectomy with fusion was performed. OUTCOMES: No signs of recurrence have been detected in 6 months of follow-up, except for mild lower back pain meeting the temperature change. LESSONS: Rapid decompression and instant therapeutic effect do not mean extending the indications of PELD. It is unreasonable to revise the recurrent LDH or treat the primary LDH with PELD under inadequate preoperative assessment.

Transforaminal endoscopy in lumbar burst fracture: A case report.

RATIONALE: Lumbar burst fractures are frequent injury resulting from high-energy trauma, and the patients suffer from pain and the neurologic dysfunction. Although minimally invasive techniques have advanced rapidly, it was the first time to apply transforaminal endoscopic combined with percutaneous pedicle screw fixation to treatment of lumbar burst fractures. PATIENT CONCERNS: A 33-year-old man underwent Magerl type A3.1 burst fracture at L2 and compression fractures at L3 due to falling from a height with severe lower back pain, sensory loss, and atony of the right leg. DIAGNOSES: Burst fracture at L2, compression fractures at L3. INTERVENTIONS: The patient was presented to 1-stage operation of percutaneous pedicle screw fixation at L1, L2, L3, and L4 instead of delayed posterior open surgery. At 1 week after injury, the 2-stage operation with a percutaneous transforaminal endoscopic was undertaken for decompression. OUTCOMES: No matter the function of nerve and imaging findings, all got ideal recoveries in just 3 days after 2-stage operation. At the 3-month follow-up, there was no loss of sagittal plane alignment, and spinal cord compression was completely relieved. The patient regained near-full neurologic function postoperatively. LESSONS: A minimally invasive surgery (ie, transforaminal endoscopic combined with percutaneous pedicle screw fixation) for the treatment of Magerl type A3.1 burst fracture at lumbar was feasible. In addition, the key to the recovery of neurological function is the complete and effective decompression of spinal.

Hypothermic Machine Perfusion in DCD Kidney Transplantation: A Single Center Experience.

INTRODUCTION: Donation after cardiac death (DCD) began in 2011 after the program hosted by the First Affiliated Hospital of Sun Yat-sen University in China. The aim of this study is to report on our experience regarding the method of preserving donated kidneys for DCD kidney transplantation. MATERIAL AND METHODS: A total of 37 donors and 73 primary kidney transplant recipients during the period 2011-2014 in the Urology Center of the First Hospital of Jilin University were enrolled in the study. Recipients were assigned to traditional static cold storage (SCS) group and hypothermic machine perfusion (HMP) group based on the preservation environment of donated kidneys after organ harvest. Clinical data were collected for each group. RESULT: The HMP group had a lower rate of delayed graft function (DGF), better postoperative recovery and kidney function compared with that of SCS group. There is no significant difference in postoperative rejection incidence between the 2 groups. CONCLUSIONS: DCD kidneys stored by hypothermic machine contribute to a lower rate of DGF and promoted the rehabilitation progress.

Serum Uric Acid and Renal Transplantation Outcomes: At Least 3-Year Post-transplant Retrospective Multivariate Analysis.

Since the association of serum uric acid and kidney transplant graft outcome remains disputable, we sought to evaluate the predictive value of uric acid level for graft survival/function and the factors could affect uric acid as time varies. A consecutive cohort of five hundred and seventy three recipients transplanted during January 2008 to December 2011 were recruited. Data and laboratory values of our interest were collected at 1, 3, 6, 12, 24 and 36 months post-transplant for analysis. Cox proportional hazard model, and multiple regression equation were built to adjust for the possible confounding variables and meet our goals as appropriate. The current cohort study lasts for 41.86 ± 15.49 months. Uric acid level is proven to be negatively associated with eGFR at different time point after adjustment for age, body mass index and male gender (standardized ß ranges from -0.15 to -0.30 with all P<0.001).Males with low eGFR but high level of TG were on CSA, diuretics and RAS inhibitors and experienced at least one episode of acute rejection and diabetic issue were associated with a higher mean uric acid level. Hyperuricemia was significantly an independent predictor of pure graft failure (hazard ratio=4.01, 95% CI: 1.25-12.91, P=0.02) after adjustment. But it was no longer an independent risk factor for graft loss after adjustment. Interestingly, higher triglyceride level can make incidence of graft loss (hazard ratio=1.442, for each unit increase millimoles per liter 95% CI: 1.008-2.061, P=0.045) and death (hazard ratio=1.717, 95% CI: 1.105-2.665, P=0.016) more likely. The results of our study suggest that post-transplant elevated serum uric acid level is an independent predictor of long-term graft survival and graft function. Together with the high TG level impact on poor outcomes, further investigations for therapeutic effect are needed.

A case of kidney transplantation using donation after circulatory death with renal calculi.

Donation after circulatory death (DCD) supplies a big percentage of the organ source pool. Compared to living-related donations, donor kidneys from DCD are commonly with lower quality since they inevitably suffer from hypoxia, hypotension, and inadequate organ perfusion during the progression to circulatory arrest. The current case presents a 44-year-old male donor with wide range subarachnoid hemorrhage and multiple skull fracture from a car accident. Multiple stones were detected in his right kidney. We performed a modified ex vivo pyelolithotomy and ureteroscopy on the bench to render a stone-free allograft. We also improved the donor kidney with hypothermic/perfusion preservation machine before renal transplantation. The recipient showed no complications during the first two-month post-operational follow-up. Such a donor kidney with stones may probably be discarded by conventional perspective. Yet, the combination of the ex vivo bench-surgery technique and hypothermic oxygenation/perfusion makes it a qualified donor kidney. Thus we have demonstrated a promising way of saving borderline qualified DCD donor kidneys.