A case report of cerebellar hemangioblastoma simulated brain metastasis shown by magnetic resonance imaging.

RATIONALE: Hemangioblastomas occur both sporadically and as an important component of von Hippel-Lindau (VHL) disease. The typical MRI features of hemangioblastoma are cysts with enhanced cystic wall nodules in the cerebellum or lesions with uniform enhancement on the surface or inside the spinal cord. If there is edema around hemangioblastoma, it is easy to be misdiagnosed as brain metastasis on MRI. PATIENT CONCERNS: A 41-year-old male patient was found to have a lump in the pancreas during a health examination 3 months ago. Subsequently, the patient underwent surgical treatment. The postoperative pathology suggests that the pancreatic lesion is a neuroendocrine tumor. The patient subsequently came to our hospital for consultation on further treatment plans. Abnormal signals were found in the right cerebellum during pituitary magnetic resonance imaging (MRI) before the development of a treatment plan for neuroendocrine tumors. Subsequently, the patient underwent cerebellar mass resection surgery. The pathological result after the surgery was hemangioblastoma. DIAGNOSIS: The patient underwent surgery to remove the tumor and was diagnosed with hemangioblastoma by pathological examination. Subsequently, the patient's genetic testing results confirmed the diagnosis of VHL syndrome. INTERVENTIONS: The patient underwent cerebellar mass resection surgery. OUTCOMES: The patient recovered after surgical resection. LESSONS: In this report, we emphasize the atypical MRI manifestations of hemangioblastoma. For patients with VHL syndrome-related hemangioblastoma, genetic testing is necessary for the patient and their family members.

Interaction of proteins with aluminum(III)-chlorophosphonazo III by resonance Rayleigh scattering method.

In weak acid medium, aluminum(III) can react with chlorophosphonazo III [CPA(III), H(8)L] to form a 1:1 coordination anion [Al(OH)(H(4)L)](2-). At the same time, proteins such as bovine serum albumin (BSA), lysozyme (Lyso) and human serum albumin (HSA) existed as large cations with positive charges, which further combined with [Al(OH)(H(4)L)](2-) to form a 1:4 chelate. This resulted in significant enhancement of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS). In this study, we investigated the interaction between [Al(OH)(H(4)L)](2-) and proteins, optimization of the reaction conditions and the spectral characteristics of RRS, SOS and FDS. The maximum RRS wavelengths of different protein systems were located at 357-370 nm. The maximum SOS and FDS wavelengths were located at 546 and 389 nm, respectively. The scattering intensities (ΔI) of the three methods were proportional to the concentration of the proteins, within certain ranges, and the detection limits of the most sensitive RRS method were 2.6-9.3 ng/mL. Moreover, the chelate reaction mechanism or the reasons for the enhancement of RRS were discussed through absorption spectra, fluorescence spectra and circular dichroism (CD) spectra.

Fluorescence quenching method for the determination of carbazochrome sodium sulfonate with aromatic amino acids.

In Britton-Robinson (BR) buffer medium (pH 3.3), carbazochrome sodium sulfonate (CSS) can react with some aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) to form a 1:1 complex by electrostatic attraction, aromatic stacking interaction and Van der Waals' force, resulting in fluorescence quenching of these amino acids. Maximum quenching wavelengths were located at 352 nm (CSS-Trp system), 303 nm (CSS-Tyr system) and 284 nm (CSS-Phe system), respectively. The fluorescence quenching value (ΔF) was proportional to the concentration of CSS in a certain range. The fluorescence quenching method for the determination of CSS showed high sensitivity, with detection limits of 31.3 ng/mL (CSS-Trp system), 44.6 ng/mL (CSS-Tyr system) and 315.0 ng/mL (CSS-Phe system), respectively. The optimum conditions of the reaction conditions and the effect of coexisting substances were investigated and results showed that the method had good selectivity. The method was successfully applied for the rapid determination of CSS in blood and urine samples. Based on the bimolecular quenching constant Kq , the effect of temperature and Stern-Volmer plots, this study showed that quenching of fluorescence of amino acids by CSS was a static quenching process.

Study on the ternary system of MoO4 (2-) -enzyme-PdCl2 by resonance Rayleigh scattering, second-order scattering and frequency-doubling scattering spectra and its analytical application.

In pH 4.0 Britton-Robinson buffer medium, PdCl2 was able to react with enzymes (EZ) such as lysozyme (LYSO) and papain (PAP) to form a coordination complex (EZ-PdCl2 ), which further reacted with MoO4 (2-) to form a ternary complex (MoO4 (2-) -EZ-PdCl2 ). As a result, the absorption and fluorescence spectra changed; new spectra of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency-doubling scattering (FDS) appeared and their intensities were enhanced greatly. The maximum RRS, SOS and FDS wavelengths of two ternary complexes were located at 310, 560 and 350 nm, respectively. The increments of scattering intensity were directly proportional to the concentrations of EZ within certain ranges. The detection limits (3σ) of LYSO and PAP were 4.5 and 14.0 ng/mL (RRS method), 9.6 and 57.8 ng/mL (SOS method), and 5.2 and 106.0 ng/mL (FDS method). Taking the MoO4 (2-) -LYSO-PdCl2 system, which was more sensitive, as an example, the effects of coexisting substances were evaluated. The methods showed excellent selectivity. Accordingly, new rapid, convenient, sensitive and selective scattering methods for the determination of LYSO and PAP were proposed and applied to determine LYSO in egg white with satisfactory results. The reaction mechanism and basis of the enhancement of scattering were discussed.

A hybrid computational model for phagocyte transmigration.

Phagocyte transmigration is the initiation of a series of phagocyte responses that are believed important in the formation of fibrotic capsules surrounding implanted medical devices. Understanding the molecular mechanisms governing phagocyte transmigration is highly desired in order to improve the stability and functionality of the implanted devices. A hybrid computational model that combines control theory and kinetics Monte Carlo (KMC) algorithm is proposed to simulate and predict phagocytes responses at molecular level. In order to mimic various biological knockout experiments, a general external control scenario is designed. The stochastic nature inherent to phagocyte transmigration is captured by KMC. A new formula is derived to calculate the transition rates as inputs to KMC. This formulation might quantify biological interactions in a general manner which is beyond the scope of the traditional chemical reaction kinetics.

Four-dimensional vascular tree reconstruction using moving grid deformation.

RATIONALE AND OBJECTIVES: Thinned perforator flaps have been widely used in plastic surgery for greater survivability and decreased morbidity. However, quantitative analysis of three-dimensional (3D) blood flow direction and location has not been examined yet. Such information will benefit and guide the surgical thinning and dissection process. Toward this goal, this study was performed for 3D vascular tree reconstruction with the incorporation of temporal contrast-agent propagation information (three spatial dimensions plus one temporal dimension; ie, 4D). MATERIALS AND METHODS: A novel computational framework by adopting a moving grid deformation method is presented. To take advantage of temporal information of the bolus propagating, a sequential segmentation procedure is proposed. Moreover, the temporal evolution of the vascular tree (4D vascular tree) is reconstructed during the procedure. RESULTS: Eight anterolateral thigh perforator flaps from eight cadavers were used for this study. The age range is 60-80 years old and the gender includes four males and four females. The 3D nature of the vascular structure and 4D vascular tree evolving process are showed in comparison with maximum intensity projection images. CONCLUSION: The proposed computational framework demonstrates effectiveness in the modeling of 4D vascular tree. Furthermore, it reveals the ability to detect small vessel tree structures that are beyond the limit of image resolution.

4D vascular tree reconstruction using moving grid deformation.

Perforator flaps have been widely used in plastic surgery for greater survivability and decreased morbidity. However, quantitative analysis of three dimensional (3D) blood flow direction and location has not been examined yet. In this paper, we reconstruct the 3D vascular tree with the incorporation of temporal information (4D) from contrast-agent propagation. A novel computational framework by adopting a moving grid deformation method is presented. To take advantage of temporal information of the bolus propagating, a sequential segmentation procedure is proposed. Moreover, the evolving of the vascular tree (4D vascular tree) is reconstructed through this procedure. Experimental results for anterolateral thigh perforator (ALTP) flap demonstrate the effectiveness of this method.