Disorganized adrenocortical zonational structure in COVID-19 patients: Implications of critical illness duration.

Aberrant adrenal function has been frequently reported in COVID-19 patients, but histopathological evidence remains limited. This retrospective autopsy study aims to scrutinize the impact of COVID-19 duration on adrenocortical zonational architecture and peripheral corticosteroid reactivity. The adrenal glands procured from 15 long intensive care unit (ICU)-stay COVID-19 patients, 9 short ICU-stay COVID-19 patients, and 20 matched controls. Subjects who had received glucocorticoid treatment prior to sampling were excluded. Applying hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining, we disclosed that the adrenocortical zonational structure was substantially disorganized in COVID-19 patients, which long ICU-stay patients manifested a higher prevalence of severe disorganization (67%) than short ICU-stay patients (11%; P = 0.0058). The adrenal cortex of COVID-19 patients exhibited a 40% decrease in the zona glomerulosa (ZG) area and a 74% increase in the zona fasciculata (ZF) area (both P < 0.0001) relative to controls. Furthermore, among long ICU-stay COVID-19 patients, the ZG area diminished by 31% (P = 0.0004), and the ZF area expanded by 27% (P = 0.0004) in comparison to short ICU-stay patients. The zona reticularis (ZR) area remained unaltered. Nuclear translocation of corticosteroid receptors in the liver and kidney of long ICU-stay COVID-19 patients was at least 43% lower than in short ICU-stay patients (both P < 0.05). These findings underscore the necessity for clinicians to monitor adrenal function in long-stay COVID-19 patients.

Can humidifier reservoir bacteria colonize the circuit during mechanical ventilation: An in vitro study.

BACKGROUND: Although the circuit condensate, an ideal bacterial reservoir during mechanical ventilation, may flow into the humidifier reservoir, no studies have investigated if humidifier reservoir colonized bacteria colonize other circuit locations with airflow. AIMS: We aimed to prove whether the humidifier reservoir colonized bacteria colonize other circuit locations with airflow and provide some advice on the disposal of condensate in the clinical setting. STUDY DESIGN: An in vitro experiment was conducted. Mechanical ventilation simulators (n = 90) were divided into sterile water group (n = 30) and broth group (n = 60). In the sterile water group, sterile water was used for humidification, either Acinetobacter baumannii or Pseudomonas aeruginosa were inoculated to humidifier water in the humidifier reservoir, each accounted for 50% of the simulators. The broth group was performed the same as the sterile water group except for the addition of broth into the humidified water. After 24, 72, and 168 h of continuous ventilation, the humidifier water and different locations of the circuits were sampled for bacterial culture. RESULTS: All bacterial culture results of the sterile water group were negative. Bacteria in the humidifier water continued to proliferate in the broth group. With prolonged ventilation, the bacteria at the humidifier reservoir outlet increased. The bacteria at the humidifier reservoir outlet were much more in the Pseudomonas aeruginosa subgroup than in the Acinetobacter baumannii subgroup and the difference was statistically significant (p < .05). During continuous ventilation, no bacterial growth occurred at 10 cm from the humidifier reservoir outlet and the Y-piece of the ventilator circuits. CONCLUSIONS: Sterile water in the humidifier reservoir was not conducive to bacterial growth. Even if bacteria grew in the humidifier reservoir and could reach the humidifier reservoir outlet, colonization of further circuit locations with the airflow was unlikely. During a certain mechanical ventilation time, the amount of bacteria reaching the outlet of the humidifier reservoir varied due to different mobility of bacteria. RELEVANCE TO CLINICAL PRACTICE: In a clinical setting, nurses should not worry about a small amount of condensate backflow into the humidifier reservoir. Draining condensate into the humidifier reservoir can be used as a low risk and convenient method in clinical practice.

COVID-19-associated monocytic encephalitis (CAME): histological and proteomic evidence from autopsy.

Severe neurological symptoms are associated with Coronavirus disease 2019 (COVID-19). However, the morphologic features, pathological nature and their potential mechanisms in patient brains have not been revealed despite evidence of neurotropic infection. In this study, neuropathological damages and infiltrating inflammatory cells were quantitatively evaluated by immunohistochemical staining, ultrastructural examination under electron microscopy, and an image threshold method, in postmortem brains from nine critically ill COVID-19 patients and nine age-matched cadavers of healthy individuals. Differentially expressed proteins were identified by quantitative proteomic assays. Histopathological findings included neurophagocytosis, microglia nodules, satellite phenomena, extensive edema, focal hemorrhage, and infarction, as well as infiltrating mononuclear cells. Immunostaining of COVID-19 brains revealed extensive activation of both microglia and astrocytes, severe damage of the blood-brain barrier (BBB) and various degrees of perivascular infiltration by predominantly CD14+/CD16+/CD141+/CCR7+/CD11c+ monocytes and occasionally CD4+/CD8+ T lymphocytes. Quantitative proteomic assays combined with bioinformatics analysis identified upregulated proteins predominantly involved in immune responses, autophagy and cellular metabolism in COVID-19 patient brains compared with control brains. Proteins involved in brain development, neuroprotection, and extracellular matrix proteins of the basement membrane were downregulated, potentially caused by the activation of transforming growth factor ß receptor and vascular endothelial growth factor signaling pathways. Thus, our results define histopathological and molecular profiles of COVID-19-associated monocytic encephalitis (CAME) and suggest potential therapeutic targets.

A map of the spatial distribution and tumour-associated macrophage states in glioblastoma and grade 4 IDH-mutant astrocytoma.

Tumour-associated macrophages (TAMs) abundantly infiltrate high-grade gliomas and orchestrate immune response, but their diversity in isocitrate dehydrogenase (IDH)-differential grade 4 gliomas remains largely unknown. This study aimed to dissect the transcriptional states, spatial distribution, and clinicopathological significance of distinct monocyte-derived TAM (Mo-TAM) and microglia-derived TAM (Mg-TAM) clusters across glioblastoma-IDH-wild type and astrocytoma-IDH-mutant-grade 4 (Astro-IDH-mut-G4). Single-cell RNA sequencing was performed on four cases of human glioblastoma and three cases of Astro-IDH-mut-G4. Cell clustering, single-cell regulatory network inference, and gene set enrichment analysis were performed to characterize the functional states of myeloid clusters. The spatial distribution of TAM subsets was determined in human glioma tissues using multiplex immunostaining. The prognostic value of different TAM-cluster specific gene sets was evaluated in the TCGA glioma cohort. Profiling and unbiased clustering of 24,227 myeloid cells from glioblastoma and Astro-IDH-mut-G4 identified nine myeloid cell clusters including monocytes, six Mo/Mg-TAM subsets, dendritic cells, and proliferative myeloid clusters. Different Mo/Mg-TAM clusters manifest functional and transcriptional diversity controlled by specific regulons. Multiplex immunostaining of subset-specific markers identified spatial enrichment of distinct TAM clusters at peri-vascular/necrotic areas in tumour parenchyma or at the tumour-brain interface. Glioblastoma harboured a substantially higher number of monocytes and Mo-TAM-inflammatory clusters, whereas Astro-IDH-mut-G4 had a higher proportion of TAM subsets mediating antigen presentation. Glioblastomas with a higher proportion of monocytes exhibited a mesenchymal signature, increased angiogenesis, and worse patient outcome. Our findings provide insight into myeloid cell diversity and its clinical relevance in IDH-differential grade 4 gliomas, and may serve as a resource for immunotherapy development. © 2022 The Pathological Society of Great Britain and Ireland.

Spatial region-resolved proteome map reveals mechanism of COVID-19-associated heart injury.

Direct myocardial and vascular injuries due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven inflammation is the leading cause of acute cardiac injury associated with coronavirus disease 2019 (COVID-19). However, in-depth knowledge of the injury characteristics of the heart affected by inflammation is lacking. In this study, using a quantitative spatial proteomics strategy that combines comparative anatomy, laser-capture microdissection, and histological examination, we establish a region-resolved proteome map of the myocardia and microvessels with obvious inflammatory cells from hearts of patients with COVID-19. A series of molecular dysfunctions of myocardia and microvessels is observed in different cardiac regions. The myocardia and microvessels of the left atrial are the most susceptible to virus infection and inflammatory storm, suggesting more attention should be paid to the lesion and treatment of these two parts. These results can guide in improving clinical treatments for cardiovascular diseases associated with COVID-19.

Dicer deficiency impairs proliferation but potentiates anti-tumoral effect of macrophages in glioblastoma.

Glioblastoma is a lethal primary brain tumor with abundant immune-suppressive glioblastoma-associated macrophage (GAM) infiltration. Skewing immune suppressive GAMs towards an immune-activating phenotype represents a promising immunotherapeutic strategy against glioblastoma. Herein, we reported that genetic deletion of miRNA-processing enzyme Dicer in macrophages inhibited the growth of GL261 murine glioblastoma xenografts and prolonged survival of tumor-bearing mice. Single cell RNA sequencing (scRNA-seq) of the tumor-infiltrating immune cells revealed that Dicer deletion in macrophages reduced the proportion of cell-cycling GAM cluster and reprogramed the remaining GAMs towards a proinflammatory activation state (enhanced phagocytotic and IFN-producing signature). Dicer-deficient GAMs showed reduced level of cyclin-dependent kinases (CDK1 and CDK2) and increased expression of CDK inhibitor p27 Kip1, thus manifesting impaired proliferation. Dicer knockout enhanced phagocytotic activity of GAMs to eliminate GL261 tumor cells. Increased proinflammatory GAM clusters in macrophage Dicer-deficient mice actively interacted with tumor-infiltrating T cells and NK cells through TNF paracrine signaling to create a pro-inflammatory immune microenvironment for tumor cell elimination. Our work identifies the role of Dicer deletion in macrophages in generating an immune-activating microenvironment, which could be further developed as a potential immunotherapeutic strategy against glioblastoma.

[Ba4Cl] Cations Directed Perovskite-like Polar Metal Formate Frameworks {[Ba4Cl][M3(HCO2)13]}n (M = Mn, Co, and Mg): Microwave-Assisted Synthesis, Structures, and Properties.

Novel 3D metal formate frameworks {[Ba4Cl][M3(HCO2)13]}n (M = Mn for 1, Co for 2, and Mg for 3) were successfully assembled via microwave-assisted synthesis. The complexes are rare coordination polymers crystallized at space group P4cc with the polar point group C4v. In the structure, the MII ions are bridged by two types of anti-anti formate in forming a 3D pcu framework, and additional formates coordinate to the unsaturated sites of the MII ions in the framework, giving an anionic M-formate net. Ba4Cl clusters take the cavities of the net as charge balance, in which the chloride ion deviates from the center of the barium ions. The asymmetric Ba4Cl structure is transmitted throughout the crystal resulting in polar structure, which is further confirmed by nonlinear optical and piezoelectric test. Nonlinear optical activity tests of 1 and 3 show SHG signals 0.32 and 0.28 times that of KDP, while 2 has a piezoelectric coefficient d33 of 6.8 pC/N along polar axis. Magnetic studies reveal antiferromagnetic coupling between MII ions in 1 and 2. Spin canting was found only in 2 with anisotropic CoII ions, and 2 is a canted antiferromagnetically with TN = 5 K. Further field-induced spin flop was also found in 2 with a critical field 0.9 T.

Pericytes augment glioblastoma cell resistance to temozolomide through CCL5-CCR5 paracrine signaling.

Glioblastoma (GBM) is a prevalent and highly lethal form of glioma, with rapid tumor progression and frequent recurrence. Excessive outgrowth of pericytes in GBM governs the ecology of the perivascular niche, but their function in mediating chemoresistance has not been fully explored. Herein, we uncovered that pericytes potentiate DNA damage repair (DDR) in GBM cells residing in the perivascular niche, which induces temozolomide (TMZ) chemoresistance. We found that increased pericyte proportion correlates with accelerated tumor recurrence and worse prognosis. Genetic depletion of pericytes in GBM xenografts enhances TMZ-induced cytotoxicity and prolongs survival of tumor-bearing mice. Mechanistically, C-C motif chemokine ligand 5 (CCL5) secreted by pericytes activates C-C motif chemokine receptor 5 (CCR5) on GBM cells to enable DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-mediated DDR upon TMZ treatment. Disrupting CCL5-CCR5 paracrine signaling through the brain-penetrable CCR5 antagonist maraviroc (MVC) potently inhibits pericyte-promoted DDR and effectively improves the chemotherapeutic efficacy of TMZ. GBM patient-derived xenografts with high CCL5 expression benefit from combined treatment with TMZ and MVC. Our study reveals the role of pericytes as an extrinsic stimulator potentiating DDR signaling in GBM cells and suggests that targeting CCL5-CCR5 signaling could be an effective therapeutic strategy to improve chemotherapeutic efficacy against GBM.

Standardizing therapeutic parameters of acupuncture in vascular dementia rats.

INTRODUCTION: Despite acupuncture having been successfully used for the clinical treatment for vascular dementia in Asian countries for centuries, scientifically rigorous evidence is lacking for standardizing therapeutic parameters. To address this problem, it is necessary to examine the parameters of acupuncture using scientific methodology. The goal of this study is to investigate various therapeutic parameters, including manipulation, retention, and frequency of acupuncture, and their contribution to the efficacy of acupuncture in VD. METHODS: We selected needle retention, treatment frequency, and needle rotation as the parameters. Acupuncture was performed on acupoints ST36 and GV20. Morris Water Maze was selected to assess the effect of acupuncture on cognitive function and Nissl staining indicated the hippocampal neuronal damage in VD rats. RESULTS: Acupuncture stimulation resulted in a significant improvement in the spatial learning and memory deficit and reversed neuronal damage in the hippocampus. The approach of needle retention with 10 min, rotation for 30s every 5 min or daily treatment with acupuncture was more effective than nonretention, nonrotation, or alternative day treatment group. CONCLUSION: This study demonstrated that needle retention, treatment frequency, and needle manipulation are important factors in improving the learning and memory as well as reducing the neuronal damage of the hippocampus in a rat VD model. These findings strongly suggest that the appropriate therapeutic parameters could significant influence the efficiency in animal experiments.

Pancreatic fistula after pancreaticoduodenectomy: Risk factors and preventive strategies.

PURPOSE: Postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD) is a worrisome and life-threatening complication. This study aimed to investigate the risk factors and preventive strategies for POPF after PD. MATERIALS AND METHODS: We retrospectively reviewed 301 consecutive patients who underwent PD at our hospitals between January 2011 and December 2017. We analyzed the pancreatic fistula rate according to the clinical characteristics, pathologic and laboratory findings, and the anastomotic methods and summarized the prevention measures. RESULTS: Postoperative morbidities included pancreatic leakage in 10.30% (31/301), delayed gastric emptying in 22.92% (69/301), abdominal infection in 6.98% (21/301), post-PD hemorrhage in 4.65% (14/301), and bile leakage in 4.98% (15/301), and the mortality rate was 2.33% (7/301). POPF was the most prominent factor for preoperative morbidity. Significant risk factors for pancreatic fistula were a soft pancreas, small pancreatic duct, tumor location, and interrupted anastomosis. Of these, soft texture, pancreatic duct <4 mm, and end-to-end anastomosis through hand suture closure were independent risk factors on multivariate analysis, while interrupted anastomosis, internal stent, and somatostatin use were risk factors in the high-risk pancreas subgroup. CONCLUSIONS: Our study demonstrated that pancreatic fistula is related to a soft texture and small pancreatic duct. The surgeon must consider these risk factors when performing PD. Thus, we propose a risk- and indication-adapted choice of anastomosis or an individualized approach for the pancreatic remnant to reduce the pancreatic fistula rate.

Applications of Acupuncture Therapy in Modulating Plasticity of Central Nervous System.

OBJECTIVE: Acupuncture is widely applied for treatment of various neurological disorders. This manuscript will review the preclinical evidence of acupuncture in mediating neural plasticity, the mechanisms involved. MATERIALS AND METHODS: We searched acupuncture, plasticity, and other potential related words at the following sites: PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and VIP information data base. The following keywords were used: acupuncture, electroacupuncture, plasticity, neural plasticity, neuroplasticity, neurogenesis, neuroblast, stem cell, progenitor cell, BrdU, synapse, synapse structure, synaptogenesis, axon, axon regeneration, synaptic plasticity, LTP, LTD, neurotrophin, neurotrophic factor, BDNF, GDNF, VEGF, bFGF, EGF, NT-3, NT-4, NT-5, p75NTR, neurotransmitter, acetylcholine, norepinephrine, noradrenaline, dopamine, monamine. We assessed the effects of acupuncture on plasticity under pathological conditions in this review. RESULTS: Relevant references were reviewed and presented to reflect the effects of acupuncture on neural plasticity. The acquired literatures mainly focused on neurogenesis, alterations of synapses, neurotrophins (NTs), and neurotranimitters. Acupuncture methods mentioned in this article include manual acupuncture and electroacupuncture. CONCLUSIONS: The cumulative evidences demonstrated that acupuncture could induce neural plasticity in rodents exposed to cerebral ischemia. Neural plasticity mediated by acupuncture in other neural disorders, such as Alzheimer's disease, Parkinson's disease, and depression, were also investigated and there is evidence of positive role of acupuncture induced plasticity in these disorders as well. Mediation of neural plasticity by acupuncture is likely associated with its modulation on NTs and neurotransmitters. The exact mechanisms underlying acupuncture's effects on neural plasticity remain to be elucidated. Neural plasticity may be the potential bridge between acupuncture and the treatment of various neurological diseases.

Magnetic Resonance Gd-RGD Imaging Study of Hepatocellular Carcinoma with High and Low Metastatic Potential before and after Human Bone Marrow-derived Mesenchymal Stem Cell Intervention.

BACKGROUND: Biotherapy based on human bone marrow-derived mesenchymal stem cells (BMSCs) is currently the focus of research, especially in the field of autologous stem cell transplantation. A novel type of metastasis-associated magnetic resonance (MR) molecular imaging probe was constructed, and the changes in metastasis and proliferation of hepatocellular carcinoma (HCC) before and after BMSC intervention were observed through MR imaging (MRI). METHODS: Metastasis-associated MR molecular imaging probe, integrin αvß3ligand cRGD-PEG-DGL-DTPA-Gd (Gd-RGD), were constructed. After human BMSC intervention was performed for 6 weeks, tumor weight inhibition rates were calculated, and the RGD molecular probe was imaged through MRI with molecular imaging agent Gd-DTPA as control. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the MRI experiment were used as semi-quantitative indicators. Polymerase chain reaction method was performed to detect proliferation- and metastasis-associated indicators, transforming growth factor ß-1 (TGFß1), osteopontin (OPN), and integrin subunit αvand ß3. RESULTS: The highest tumor weight inhibition rates were observed 3 weeks after the BMSC transplantation. The MR Gd-RGD in the HCC tissues after the BMSC intervention showed less enhancement than Gd-DTPA. The Gd-DTPA MRI of control group had higher SNR and CNR than Gd-RGD MRI in the experimental groups (P < 0.05). For high metastatic potential hepatocellular carcinoma (MHCC97-H), significant differences were observed in the SNRs and CNRs of Gd-RGD MRI before and after the BMSC intervention (P < 0.05). For low metastatic potential hepatocellular carcinoma (MHCC97-L), the CNRs of Gd-RGD MRI were statistically different before and after BMSC intervention (P < 0.05). With regard to MHCC97-H, OPN, ß3, and TGFß1 expression significantly decreased after BMSC intervention (P < 0.05). In MHCC97-L and OPN, ß3, TGFß1, and αv expression after BMSC intervention decreased, and the difference was statistically significant (P < 0.05). CONCLUSIONS: The CNR index of MRI is a good indicator for distinguishing high- and low-metastatic potential HCC tissues. After BMSC transplantation of MRI through the two kinds of tracer, the SNR and CNR indexes can distinguish two kinds of high and low metastatic potential HCC tissues, and Gd-RGD imaging is more suitable in distinguishing the metastatic potential changes through BMSC intervention.

Acupuncture Attenuated Vascular Dementia-Induced Hippocampal Long-Term Potentiation Impairments via Activation of D1/D5 Receptors.

BACKGROUND AND PURPOSE: Emerging evidence suggests that acupuncture could improve cognitive impairment in vascular dementia by enhancing synaptic plasticity in the hippocampus. The purpose of this study is to investigate whether dopamine, a key mediator of synaptic plasticity, is involved in this cognitive improvement. METHODS: Vascular dementia model was established by bilateral common carotid arteries occlusion in male Wistar rats. Three days after the operation, animals received acupuncture treatment for 2 weeks, once daily. The D1/D5 receptors antagonist SCH23390 was administered intraperitoneally 15 minutes before each acupuncture treatment. Morris water maze was examined after acupuncture. Long-term potentiation was studied by an electrophysiological technique. Dopamine and metabolites levels were detected by microdialysis and high-performance liquid chromatography from brain tissue. The expression of D1R and D5R was analyzed by immunofluorescence. RESULTS: Acupuncture remarkably reversed cognitive deficits in 2-vessel occlusion model (2VO) rats, and the acupuncture points Zusanli (ST36) and Baihui (GV20) were confirmed to be the most effective combination. Electrophysiological recording data showed that 2VO-induced impairments of long-term potentiation were prevented by acupuncture. In addition, acupuncture promoted the release of dopamine and its major metabolites in the hippocampus of 2VO rats. The immunofluorescence experiment showed that the decrease of D1R and D5R in hippocampal dentate gyrus region of 2VO rats was reversed by acupuncture. Furthermore, we found that the effects of acupuncture against 2VO-induced impairments in cognition and synaptic plasticity were abolished by SCH23390. CONCLUSIONS: Improvement in cognition and hippocampal synaptic plasticity induced by acupuncture was achieved via activation of D1/D5 receptors in 2VO rats.

Comparison of Positron Emission Tomography Using 2-[18F]-fluoro-2-deoxy-D-glucose and 3-deoxy-3-[18F]-fluorothymidine in Lung Cancer Imaging.

BACKGROUND: The detection of solitary pulmonary nodules (SPNs) that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography (CT) imaging results remains a significant challenge. The 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-[18F]-fluorothymidine (18F-FLT) in lung cancer PET/CT imaging. METHODS: The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established (n = 12), and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values (SUVs), and Ki-67 proliferation marker expression were investigated. RESULTS: The cell-tracer binding ratio for the A549 cells using the 18F-FDG was greater than the ratio using 18F-FLT (P < 0.05). The Ki-67 expression showed a significant positive correlation with the 18F-FLT binding ratio (r = 0.824, P< 0.01). The tumor-to-nontumor uptake ratio of 18F-FDG imaging in xenografts was higher than that of 18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of 18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of 18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of 18F-FDG and 18F-FLT (r = 0.658, P< 0.05 and r = 0.724, P< 0.01, respectively). CONCLUSIONS: The 18F-FDG uptake ratio is higher than that of 18F-FLT in A549 cells at the cellular level. 18F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.

Quantitative T2 mapping evaluation for articular cartilage lesions in a rabbit model of anterior cruciate ligament transection osteoarthritis.

BACKGROUND: Quantitative T2 mapping has been a widely used method for the evaluation of pathological cartilage properties, and the histological assessment system of osteoarthritis in the rabbit has been published recently. The aim of the study was to investigate the effectiveness of quantitative T2 mapping evaluation for articular cartilage lesions of a rabbit model of anterior cruciate ligament transection (ACLT) osteoarthritis. METHODS: Twenty New Zealand White (NZW) rabbits were divided into ACLT surgical group and sham operated group equally. The anterior cruciate ligaments of the rabbits in ACLT group were transected, while the joints were closed intactly in sham operated group. Magnetic resonance (MR) examinations were performed on 3.0T MR unit at week 0, week 6, and week 12. T2 values were computed on GE ADW4.3 workstation. All rabbits were killed at week 13, and left knees were stained with Haematoxylin and Eosin. Semiquantitative histological grading was obtained according to the osteoarthritis cartilage histopathology assessment system. Computerized image analysis was performed to quantitate the immunostained collagen type II. RESULTS: The average MR T2 value of whole left knee cartilage in ACLT surgical group ((29.05±12.01) ms) was significantly higher than that in sham operated group ((24.52±7.97) ms) (P=0.024) at week 6. The average T2 value increased to (32.18±12.79) ms in ACLT group at week 12, but remained near the baseline level ((27.66±8.08) ms) in the sham operated group (P=0.03). The cartilage lesion level of left knee in ACLT group was significantly increased at week 6 (P=0.005) and week 12 (P<0.001). T2 values had positive correlation with histological grading scores, but inverse correlation with optical densities (OD) of type II collagen. CONCLUSION: This study demonstrated the reliability and practicability of quantitative T2 mapping for the cartilage injury of rabbit ACLT osteoarthritis model.

Magnetic resonance urography and X-ray urography findings of congenital megaureter.

OBJECTIVE: To observe the imaging findings of congenital megaureter in order to enhance the understanding of this disease. METHODS: Image data of 5 patients with congenital megaureter and 2 misdiagnosed patients were analyzed, and image findings of congenital megaureter were summarized.Elscint Prestig 2.0T superconductive magnetic resonance urography (MRU) with conventional sequence (spin-echo, T1WI560 ms/16 ms; fast spin-echo, T2WI 9600 ms/96 ms ) was performed. Raw data were acquired with fastspin-echo sequence from heavy T2-weighted image (9600 ms/120 ms). Post-processing method of MRU was the maximum intensity projection with three-dimensional reconstruction in the workstation. Intravenous pyelography (IVP) was conducted, in which X-rayfilms were taken 7 minutes, 15 minutes, and 30 minutes after injecting contrast agent, exceptthat in 2 patients the films were taken delayed at 60 and 90 minutes .X-ray retrograde pyelography was performed on 2 patients, successful in one butfailed in the other. RESULTS: The dilated ureter showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images in conventional MRI. The mass wall was intact, uniform in thickness, and showing hypointensity on T1-weighted and T2-weighted images. The MRU images showed a retroperitoneal mass appearing as an elongated tubular cystic structure spreading from kidney to bladder. MRU also revealed dilated calices and renal pelvis, pelviureteric obstruction, and renal duplication. The main signs of congenital megaureter in X-urography was significant dilatation of ureter, or normal renal pelvis with ureter dilatation, hydronephrosis, deformity, and displacement. CONCLUSIONS: MRU with X-urography could visualizethe characteristics of congenital megaureter, including the dilation of renal pelvis and ureter, calculi, urinary tract duplication, and stenosis location. The two techniques can complement each other in disease diagnosis and provide more detailed information for preoperative treatment.

Pitfalls in positron emission tomography/computed tomography imaging: causes and their classifications.

OBJECTIVE: To describe the pitfalls in positron emission tomography/computed tomography (PET/CT) imaging and classify them according to the principles of their generation. METHODS: We summarized retrospectively the 18F-fluorodeoxyglucose (FDP) PET/CT imaging pitfalls through reviewing the PET/CT images of 872 patients. The pitfalls were divided into artifacts and infrequent physiological uptake, and the artifacts were further classified according to their causes. Meanwhile, we calculated the incidences of various pitfalls. Whether the PET/CT pitfalls influenced the diagnostic decision was analyzed. The appearances of pitfalls in PET were also described. RESULTS: Pitfalls could be found in PET/CT images of 684 (78.4%) patients. Artifacts were found in 664 (76.15%) patients, and could be classified into self-factor artifacts and equipment- or technology-related artifacts. Among self-factor artifacts, respiratory motion (57.5%), postprandial or hyperglycemia artifacts (2.41%), and metal or high density matter artifacts (1.38%) were frequent. As for equipment- or technology-related factors, injection point outleakage or radiotracer contamination (13.88%) and truncation artifacts (1.83%) were most common ones. Infrequent physiological FDG uptakes, including fatty uptake, endometrial uptake, and bilateral breast feeding period uptake, were found in 20 (2.29%) patients. Among all pitfalls, the artifacts in 92 (13.4%) patients and infrequent physiological uptakes in 6 (0.88%) patients affected the diagnostic results. Artifact images in PET could be described as hot or cold area and the images of infrequent physiological uptake were always shown as hot area. CONCLUSIONS: The incidence of pitfall in PET/CT imaging was high and the causes of pitfalls are various. Among all causes that artifacts generated, respiratory motion is the most common. Some pitfalls may disturb clinical physicians' decision, so it is important to recognize artifacts and physiological uptake, and distinguish them from pathological uptakes.

[Comparing serum tumor antigen detection combined with CT scan with PET-CT for lung cancer diagnosis].

BACKGROUND & OBJECTIVE: Positron emission tomography-computed tomography (PET-CT) is a new bio-imaging system which combined metabolic with anatomic imaging. This system has better three-dimensional definition and earlier tumor detection potential. This study was to compare the accuracy of tumor antigen detection combined with CT scan with PET-CT for lung cancer diagnosis and staging. METHODS: A total of 43 lung cancer patients diagnosed by operation or acupuncture, received breast CT scan, tumor antigen detection, and PET-CT scan, were selected. The accuracies of these 2 methods and their impacts on lung cancer staging were compared. RESULTS: The accurate diagnosis rate of tumor antigen detection combined with CT scan was 67.44%, and that of PET-CT scan was 90.70%. Local focus detection rates were 86.05% and 95.35%, respectively; mediastinal lymph nodes detection rates were 65.12% and 83.72%, respectively. PET-CT detected 6 cases of distant metastasis which were not detected by tumor antigen detection combined with CT scan. Compared with CT scan, 5 (11.63%) cases were upstaged and 7 (16.28%) cases were downstaged by PET-CT, which led to therapeutic strategy changes in 4 (9.3%) cases. CONCLUSION: Compare with tumor antigen detection combined with CT scan, PET-CT scan is more sensitive and accurate in diagnosing and staging lung cancer.

[Clinical application of 16-slice spiral CT coronary angiography].

OBJECTIVE: To assess the clinical value of multislice spiral CT coronary angiography (MSCTCA). METHODS: Totally 79 patients were examined with MSCTCA and the CT images were reconstructed by several methods to analyze the factors crucial for the image quality, the ability of MSCT displaying the coronary artery vessels, along with the nature and calcification degrees of the plaques. The presence as well as the degree of vascular stenosis, visualization of the bypass graft, implanted stents and patency of the vessels were evaluated. RESULTS: The left main coronary artery and the left anterior descending artery were all best visualized in 75% R-R phases while the right coronary artery and the left circumflex artery in 62.5% R-R phases. CT images obtained by volume rendering showed the best quality at 75% R-R phases. 16-slice spiral CT was able to display from the primary to the tertiary, and even the quaternary branches of the coronary artery, and clearly displayed the coronary plaques, stenosis, implanted stents and bypass grafts. CONCLUSION: MSCTCA has a good clinical value in the primary identification of coronary heart disease and reexamination after revascularization.