Accumulation of LDL/ox-LDL in the necrotic region participates in osteonecrosis of the femoral head: a pathological and in vitro study

Background Osteonecrosis of the femoral head (ONFH) is a common but intractable disease that appears to involve lipid metabolic disorders. Although numerous studies have demonstrated that high blood levels of low-density lipoprotein (LDL) are closely associated with ONFH, there is limited evidence to explain the pathological role of LDL. Pathological and in vitro studies were performed to investigate the role of disordered metabolism of LDL and oxidized LDL (ox-LDL) in the femoral head in the pathology of ONFH. Methods Nineteen femoral head specimens from patients with ONFH were obtained for immunohistochemistry analysis. Murine long-bone osteocyte Y4 cells were used to study the effects of LDL/ox-LDL on cell viability, apoptosis, and metabolism process of LDL/ox-LDL in osteocytes in normoxic and hypoxic environments. Results In the pathological specimens, marked accumulation of LDL/ox-LDL was observed in osteocytes/lacunae of necrotic regions compared with healthy regions. In vitro studies showed that ox-LDL, rather than LDL, reduced the viability and enhanced apoptosis of osteocytes. Pathological sections indicated that the accumulation of ox-LDL was significantly associated with impaired blood supply. Exposure to a hypoxic environment appeared to be a key factor leading to LDL/ox-LDL accumulation by enhancing internalisation and oxidation of LDL in osteocytes. Conclusions The accumulation of LDL/ox-LDL in the necrotic region may contribute to the pathology of ONFH. These findings could provide new insights into the prevention and treatment of ONFH.

Considerations for Whole-Slide Analysis of Murine Xenografts Experiments

Histochemistry of tumor sections is a widely employed technique utilized to examine cell death in preclinical xenograft animal models of cancer. However, this is under the assumption that tumors are homogeneous, leading to practices such as automatic cell counting across the entire section. We have noted that in our experiments the core of the tumor is largely or partially necrotic, and lacks evidence of vascularization (in contrast to the outer areas of the tumor). We note that this can bias and confound immunohistochemical analyses that do not take care to sample areas of interest in a way to take this into account. Design-based stereology with image analysis techniques is an alternative process that could be used to measure the volume of the necrotic region compared to the volume of the whole tumor.

Differences in the Microarchitectural and Histomorphologic Characteristics Between Glucocorticoid-induced Osteonecrosis of Femoral Head and Alcohol-induced Osteonecrosis of Femoral Head

AimsTo analyze microarchitecture and histomorphology characteristics of different regions in femoral heads from patients with glucocorticoid-induced osteonecrosis of femoral head (GIONFH) and alcohol-induced osteonecrosis of femoral head (AIONFH). MethodsPatients diagnosed with GIONFH and AIONFH were recruited. Femoral heads were obtained after total hip replacement. Micro-CT was applied to evaluate the microstructure of 9 regions of interest (ROIs) in the femoral head. Along the supero-inferior orientation, the femoral head was divided into necrotic region, reactive interface, and normal region; along the medio-lateral orientation, the femoral head was divided into medial region, central region and lateral region. Decalcified and undecalcified bone histology were then performed to assess histopathological alterations and bone remodeling levels. Results42 GIONFH patients (50 hips) and 43 AIONFH patients (50 hips) anticipated in the study. In the necrotic region, most of the microarchitectural parameters did not differ significantly between GIONFH and AIONFH, whereas both the reactive interface and normal region illustrated significant differences in the microstructure and histomorphometry. The reactive interface and normal region exhibited a less sclerotic microarchitecture, but a higher bone remodeling level in GIONFH as compared with AIONFH. Despite similar necrotic pathological manifestations, subchondral trabecular microfracture in the necrotic region was more severe and vasculature of the reactive interface was more abundant in GIONFH. ConclusionsAlthough these two subtypes of ONFH shared similar microarchitecture and pathological features in the necrotic region, GIONFH exhibited a less sclerotic microarchitecture and a more active bone metabolic status in both the reactive interface and normal region.

Arterial instillation of rapamycin in treatment of rabbit hepatic xenograft tumors and its effects on VEGF, iNOS, HIF-1α, Bcl-2, Bax expression and microvessel density

Hepatocellular carcinoma is one of the leading causes of malignant tumor related death word wide with poor prognosis. Chemotherapy and TACE are main treatment methods for advanced stage cases. Rapamycin, a macrolide compound that initially used to coat coronary stents, can inhibit the growth of a variety of cancer cells especially hepatocellular carcinoma. Twenty-four healthy adult New Zealand white rabbits underwent CT-guided puncture to prepare a model of VX2 liver xenograft tumor. The rabbits were randomly divided into four groups with six in each group and received the following treatments: APR-TACE1: arterial perfusion of high-dose rapamycin combined with TACE; APR-TACE2: arterial perfusion of low-dose rapamycin combined with TACE; TACE: TACE alone; and IVR-TACE: intravenous injection of rapamycin combined with TACE. Two weeks after TACE treatment, the rabbits received CT scan and DSA angiography examination, and then killed by air embolism. The non-necrotic region and surrounding tissues were obtained from the peripheral tumor for iNOS, HIF-1α, VEGF, Bcl-2, and Bax protein expression analysis. Protein expression of iNOS, HIF-1α, VEGF, and Bcl-2 in APR-TACE1 were significantly lower than those in groups APR-TACE2, TACE, and IVR-TACE ( p < 0.05). iNOS, HIF-1α, and VEGF in APR-TACE2 were lower than those in TACE ( p < 0.05). iNOS and VEGF in APR-TACE2 were significantly lower than those in IVR-TACE ( p < 0.05). iNOS in IVR-TACE was significantly lower than that in TACE ( p < 0.05). The expression levels of Bcl-2 and Bax were statistically significant between APR-TACE2 and TACE ( p < 0.05). The MVD of the tumor tissue in APR-TACE1 was lower than that of groups APR-TACE2, TACE, IVR-TACE with statistical difference ( p < 0.05). However, MVD of APR-TACE2 was lower than that of groups TACE, IVR-TACE with significant statistical difference ( p < 0.05). Arterial instillation of rapamycin+TACE in treatment of rabbit hepatic xenograft tumors can reduce tumor neovascularization and inhibit iNOS, HIF-1α, VEGF, Bcl-2, and Bax protein expression.

Estimation of Dose Enhancement for Inhomogeneous Distribution of Nanoparticles: A Monte Carlo Study

High atomic number nanoparticles are of increasing interest in radiotherapy due to their significant positive impact on the local dose applied to the treatment site. In this work, three types of metal nanoparticles were utilized to investigate their dose enhancement based on the GATE Monte Carlo simulation tool. Gold, gadolinium, and silver were implanted at three different concentrations to a 1 cm radius sphere to mimic a cancerous tumor inside a 10 × 10 × 30 cm3 water phantom. The innermost layer of the tumor represents a necrotic region, where the metal nanoparticles uptake is assumed to be zero, arising from hypoxic conditions. The nanoparticles were defined using the mixture technique, where nanoparticles are added to the chemical composition of the tumor. A directional 2 × 2 cm2 monoenergetic photon beam was used with several energies ranging from 50 keV to 4000 keV. The dose enhancement factor (DEF) was measured for all three metal nanoparticles under all beam energies. The maximum DEF was ~7 for silver nanoparticles with the 50 keV beam energy at the highest nanoparticle concentration of 30 mg/g of water. Gold followed the same trend as it registered the highest DEF at the 50 keV beam energy with the highest concentration of nanoparticles at 30 mg/g, while gadolinium registered the highest at 100 keV.

Studies on Leaf Blight Disease of Sissoo (Dalbergia sissoo Roxb.) in Bangladesh

The outbreak of leaf blight disease in sissoo (Dalbergia sissoo Roxb.) was detected in different plantation areas of Sylhet, Bangladesh, during surveys conducted in November 2019. Isolates were consistently recovered from the necrotic region of the blight infected leaves. Isolates grown on potato-dextrose-agar (PDA) showed greyish-white cottony mycelia with a concentric zone of orange conidial masses. Average conidia length and width ranging from 13.5-17.7 µm and 3.5-5.3 µm, respectively. In the pathogenicity test, the pathogen was able to cause infection on detached healthy leaves and spots developed were similar to those observed on the leaves affected in nature. However, the pathogen produced disease symptoms in wounded leaves but did not produce any symptoms on the non-wound ones. Findings also suggested that the pathogen was equally virulent to three-leaf grades (young, middle and mature-aged). Based on the above morphological features, the pathogen was identified as Colletotrichum sp. Molecular identification is needed to determine the pathogen up to species. The observation of the pathogen causing leaf blight disease of sissoo in Bangladesh has severe implications regarding the management of plantations and nurseries. More surveys are needed to determine the distribution and extent of damage caused by the pathogen in other regions.

Cerebrospinal fluid leakage due to nasoseptal flap partial necrosis: A pitfall for skull base reconstruction of endoscopic endonasal surgery

Background: Vascularized nasoseptal flaps allow for the reconstruction of large dural defects and have remarkably reduced the incidence of postoperative complications during endoscopic endonasal skull base surgery. Nevertheless, some complications related to nasoseptal flap have been reported. Flap necrosis is a rare, but serious issue is associated with meningitis and cerebrospinal fluid (CSF) leak. Case Description: We performed endoscopic endonasal removal of the tuberculum sella meningioma in a 39-year-old woman with a history of Turner syndrome using abdominal fat, fascia, and a vascularized nasoseptal flap for dural and skull base defect reconstruction. After surgery, she developed CSF leak, and reoperation revealed partial necrosis of the septal flap that caused leakage. At this time, with a concern that removal of the necrotic part may lead to the insufficient size of the flap, we filled the gap tightly with fat pieces. However, the CSF leak recurred, and thus, we performed debridement of the necrotic region and reformed the multilayered reconstruction, following which she no longer experienced CSF leakage. Conclusion: Our case suggested that partial rather than total flap necrosis could occur, possibly due to variances of vascular anatomy, leading to focal ischemia. Debridement of the necrotic region may be an important solution for recurrent cerebrospinal leakage secondary to partial necrosis of a nasoseptal flap.

NIMG-51. THE CENTRALLY RESTRICTED DIFFUSION SIGN FOR DIFFERENTIATION BETWEEN TREATMENT-RELATED LESIONS AND TUMOR PROGRESSION IN GLIOMA PATIENTS: A VALIDATION STUDY

BACKGROUND The aim of the study was to compare the diagnostic accuracy of different diffusion patterns for differentiation between treatment-related lesions and true tumor progression in patients with suspected glioma recurrence. METHODS A retrospective analysis of a prospective cohort was conducted. The images of 240 consecutive patients who underwent surgery for suspected glioma recurrence were reviewed for potential inclusion. Exclusion criteria were lack of a ring-enhancing lesion and presence of susceptibility artifact. Final diagnosis was established upon review of histopathology reports. Lesions showing treatment-related changes and less than 25% of viable tumor were considered treatment-related lesions. More than 25% of viable tumor was considered recurrent tumor. A neuroradiologist, blinded to the diagnosis, evaluated the diffusion patterns on preoperative MRI. ROC curve analysis was performed. RESULTS One hundred and ten patients were included (26 with treatment-related lesions and 84 with tumor progression). Of 110, 35 showed no reduced diffusion. Fifty patients had reduced diffusion in the solid lesion component (84%, recurrent tumor and 16%, treatment-related lesions). Twenty-five patients showed reduced diffusion within the central necrosis (48%, recurrent tumor and 52%, treatment-related lesions). Most cases with reduced diffusion in the central necrotic region showed mixed pathology with concurrent treatment effect and viable tumor. The AUC for the combined diffusion pattern (reduced diffusion in the solid lesion component vs in the necrotic region) was 0.68 (95%CI=0.55–0.81). The AUC for the traditional diffusion approach (reduced diffusion in the solid lesion component vs no reduced diffusion) was 0.59 (95%CI=0.49–070). No significant differences were found in AUC (p=0.3). CONCLUSION Although the existence of centrally reduced diffusion seems to be associated with the presence of treatment effect, it does not significantly increase the diagnostic accuracy of the traditional diffusion evaluation approach. This is most likely related to the high incidence of concurrent recurrent tumor and treatment effect.

Clinical and pathological aspects of gossypiboma in a dog: case report

ABSTRACT A female dog was treated at the Veterinary Hospital Governador Laudo Natel for symptomscaused by an intra-abdominal gossypiboma (gossypium: cotton; boma: place of hiding). Showing high morbidity and mortality, the gossypiboma is a granulomatous reaction that is formed in response to exposure to a textile matrix. The objective of this report is to describe the clinical and pathological findings of an intra-abdominal gossypiboma in a female dog. This patient arrived at urgent care showing increased abdominal volume, pain, and cachexia. Ultrasonography showed a regular contour formation that could not be completely delimited. The patient underwent exploratory laparotomy and died in the postoperative period. The gossypiboma had a smooth, firm, and purple-gray exterior surface. Microscopy revealed a severe reaction of desmoplasia around the necrotic region, residual textile material, and adipose tissue. Negligence by veterinarians leading to this condition can result in patients’ death as well as causing psychological damage to owners.