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Biomedical subjects

Yun Chen

Publications and source records attributed to Yun Chen.

At least 55 records · Page 3Linked to original sources
PubMed2005

Effects of irradiated tumor vaccine and infusion of granulocyte-macrophage colony-stimulating factor and interleukin-12 on established gliomas in rats.

PURPOSE: We investigated granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-12 (IL-12) infused into the injection site of irradiated tumor vaccine (TV) as therapy for gliomas. METHODS: Rats with subcutaneous RT-2 gliomas were treated with irradiated TV and/or subcutaneous infusion of GM-CSF and/or IL-12 via osmotic minipump 5 days after tumor-cell inoculation. Cytotoxic T lymphocyte (CTL) and natural killer (NK) cell activity were analyzed to investigate immune responses. Rats with intracerebral gliomas were treated with irradiated TV and infused GM-CSF/IL-12 3 days after tumor-cell inoculation. Tumor growth rates and animal survival were followed. Survivors were re-challenged with wild-type RT-2 cells subcutaneously or intracerebrally to study long-term anti-tumor immunity. RESULTS: Rats with subcutaneous gliomas treated with GM-CSF and IL-12 or TV plus GM-CSF or IL-12 did not have increased survival rate (P>0.2), but did have prolonged survival time (P<0.05); in contrast, rats treated with TV plus GM-CSF/IL-12 had increased survival rate (P<0.05) and prolonged survival time (P<0.05) compared with controls. These treatment strategies showed enhanced CTL and NK cell activities. Rats with intra-cerebral gliomas treated with TV plus GM-CSF/IL-12 did not have increased survival rate (P=0.11), but did have prolonged survival time (P<0.0001). Survivors in each group were re-challenged with wild-type RT-2 cells, and all had long-term survival. CONCLUSIONS: Irradiated TV plus continuous localized infusion of GM-CSF/IL-12 may induce a tumor-specific anti-tumor immune response on established subcutaneous or intra-cerebral gliomas, and such a treatment strategy deserves consideration as adjuvant treatment for glioma.

Animals↗
PubMed2005

High-performance liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry determination of zaleplon in human plasma.

A sensitive and specific liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry (LC-APCI-MS) method has been developed and validated for the identification and quantification of zaleplon in human plasma using estazolam as an internal standard (IS). After the addition of estazolam and 2.0 M sodium hydroxide solution, plasma samples were extracted with ethyl acetate and then the organic layer was evaporated to dryness. The reconstituted solution of the residue was injected onto a prepacked Shim-pack VP-ODS C18 (250 mm x 2.0 mm i.d.) column and chromatographed with a mobile phase comprised of methanol:water (70:30) at a flow-rate of 0.2 ml/min. Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via atmospheric pressure chemical ionization (APCI) source. The mean standard curve was linear (r = 0.9991) over the concentration range of 0.2-100 ng/ml and had good back-calculated accuracy and precision. The intra-day and inter-day precisions were within 10% relative standard deviation and accuracy ranged from 85% to 115%. The limit of detection was 0.1 ng/ml. The validated LC-APCI-MS method has been used successfully to study zaleplon pharmacokinetic, bioavailability and bioequivalence in 18 adult volunteers.

Acetamides↗
PubMed2005

Measuring the doxorubicin content of single nuclei by micellar electrokinetic capillary chromatography with laser-induced fluorescence detection.

Individual nuclei isolated from the human leukemia CCRF-CEM and CEM-C2 cells treated with doxorubicin (DOX) were in-column lysed with a sodium dodecyl sulfate (SDS) containing buffer, their contents were then separated by micellar electrokinetic capillary chromatography using the same lysing buffer, and the DOX content was detected by laser-induced fluorescence. Use of a microscope for the selection of one nucleus from the nuclear preparation decreases the possibility of introduction of other subcellular components that are commonly found as impurities in subcellular fractions. The presence of SDS in the running buffer made negligible the DNA's quenching effect on DOX fluorescence, which often compromises quantification of DOX by direct imaging, making it possible to carry out the first direct measurement of the doxorubicin content of isolated nuclei. On average, nuclei from CCRF-CEM and CEM/C2 cell lines contained 85 +/-64 (n = 6) and 91 +/- 51 (n =7) amol of DOX, respectively. These values correspond to 74 and 65% of the average total cellular content as determined by single-cell analysis of the corresponding cell types. It is envisioned that this approach could become an important bioanalytical tool to investigate the effect of treatments with fluorescent drugs targeting the nucleus.

Cell Line, Tumor↗
PubMed2005

Detection and analysis of anti-latent membrane protein 2A antibodies in the sera of patients with Epstein-Barr virus associated malignancies.

BACKGROUND: Epstein-Barr virus (EBV) associated malignancies with a Type II latency gene expression pattern, such as Hodgkin's disease, and nasopharyngeal carcinoma (NPC), frequently express the EBV antigen latent membrane protein 2A (LMP2A). We expected to establish a highly expressing LMP2A yeast cell strain and get the high quality LMP2A protein, which was used for detection, analysis and characterization of its antibodies in various patients' sera of EBV associated malignancies. METHODS: The plasmid pPICZalphaA-LMP2A containing the full length of LMP2A cDNA was constructed and transformed to Pichia pastoris GS115 to express LMP2A protein. After fermentation and purification, the LMP2A protein was used as an antigen to detect anti-LMP2A antibodies (Abs) in the sera of patients with EBV-associated malignancies in enzyme linked immunosorbent assay (ELISA) or Western-blot. RESULTS: LMP2A was expressed successfully with an expected molecular weight of approximately 54 kD and Abs to LMP2A were strikingly specific to NPC. Two-thirds or more sera from NPC patients were positive for anti-LMP2A immunoglobulin G (IgG) Abs. The antibodies were absent from the sera of other EBV-associated diseases except a small fraction of the gastric carcinoma. Comparing anti-viral capsid Ags (VCA) IgA and LMP2A IgA titers in the sera from 76 NPC patients, only 55% were positive for anti-LMP2A IgA Abs while 70% were positive for anti-VCA IgA. However, we found that 3 sera negative for VCA IgA were positive for LMP2A IgA. CONCLUSION: The results suggested the potential significance of LMP2A specific Abs for the diagnosis of EBV-associated malignancies, especially NPC.

Antibodies, Viral↗
PubMed2005

Selective determination of the doxorubicin content of individual acidic organelles in impure subcellular fractions.

Since organelle preparations often contain more than one organelle type (e.g., acidic organelles and mitochondria), techniques that measure the properties of a given organelle type while avoiding biases caused by ancillary subcellular compartments are highly desirable. We report here the use of capillary electrophoresis (CE) with laser-induced fluorescence (LIF) dual-channel detection to identify acidic organelles containing doxorubicin (DOX) in crude subcellular fractions from CCRF-CEM and CEM/C2 cell lines. As confirmed by confocal microscopy, acidic organelles are identified by their accumulation of fluorescently labeled nanospheres. Using CE-LIF analysis, individually detected organelles are classified into three kinds: acidic organelles containing only nanospheres, acidic organelles containing nanospheres and DOX, and other organelles containing DOX (e.g., mitochondria) with no detectable nanospheres. Electrophoretic mobility, DOX fluorescence intensity, and nanosphere fluorescence intensity distributions of individual acidic organelles and other organelles containing DOX are determined in the same CE-LIF run. The acidic organelle mobilities range from (-0.7 to -2.0) x 10(-4) cm(2) V(-1) s(-1) while those of the other organelles spread from (-0.6 to -3.5) x 10(-4) cm(2) V(-1) s(-1). In addition, by calibrating the detector response, DOX content in individual acidic organelles and other organelles can be estimated. The average amounts of DOX per acidic organelle in CEM/C2 and CCRF-CEM cells are 11.1 +/- 0.5 and 10.6 +/- 0.4 zmol, respectively. This first report of an analysis of the accumulation of DOX in individual acidic organelles presents a procedure for analyzing the accumulation of fluorescent compounds in acidic organelles that could be useful for investigating acidic organelle maturation and the role of these organelles in drug resistance.

Antibiotics, Antineoplastic↗
PubMed2005

Induction of T-cell apoptosis in rats by genetically engineered glioma cells expressing granulocyte-macrophage colony-stimulating factor and B7.1.

PURPOSE: To evaluate antitumor effects on intracerebral gliomas of genetically engineered tumor vaccines expressing granulocyte-macrophage colony-timulating factor (GM-CSF), B7.1, or both (combination). EXPERIMENTAL DESIGN: A rat glioma cell line, RT-2, was engineered with a retroviral vector to express GM-CSF, B7.1, or combination. Tumorigenicity of engineered cells and therapeutic effects of s.c. given irradiated or live tumor vaccines on parental intracerebral gliomas were studied. Immune cell infiltration induced at vaccine and tumor sites was examined by histologic and immunohistochemical staining. Apoptosis of T cells from vaccine sites was analyzed with fluorescence-activated cell sorting. RESULTS: Engineered RT-2 cells exhibited reduced s.c. tumorigenicity in rats with reduced tumor growth and prolonged animal survival time compared with control rats. Rats with intracerebral gliomas s.c. treated with irradiated or live GM-CSF-expressing vaccines had 60% and 100% survival rates, respectively, significantly better than the control groups (P < 0.05). In contrast, rats treated with vaccines expressing B7.1 or the combination had no or mild therapeutic effects. Studies revealed less T-cell infiltration at both vaccine and tumor sites in rats treated with vaccines expressing B7.1 or the combination than in rats treated with a vaccine expressing GM-CSF. Cell sorting analyses revealed higher proportions of apoptotic T cells at vaccine sites of rats treated with the combination than those treated with vaccine expressing GM-CSF. CONCLUSIONS: Combination of GM-CSF- and B7.1-expressing tumor vaccines exerted no synergistic, or even worse, therapeutic effects on gliomas compared with single GM-CSF-secreting tumor vaccine. The worse therapeutic effects of the GM-B7.1-expressing tumor vaccine than the GM-CSF-expressing tumor vaccine were related to the reduced T-cell amount and increased T-cell apoptosis in the former.

Animals↗
PubMed2005

Formation of apatite on poly(alpha-hydroxy acid) in an accelerated biomimetic process.

Bonelike apatite coating was formed on poly(L-lactic acid) films and poly(glycolic acid) scaffolds within 24 h through an accelerated biomimetic process. The ion concentrations in the simulated body fluid (SBF) were nearly 5 times of those in the human blood plasma. The apatite formed was characterized by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The apatite formed in 5SBFs was similar in morphology and composition to that formed in the classical biomimetic process using SBF or 1.5SBF and similar to that of natural bone. This indicated that the biomimetic apatite-coating process could be accelerated by using concentrated simulated body fluid at 37 degrees C. Besides saving time, the accelerated biomimetic process is particularly significant to biodegradable polymers. Some polymers that degrade too fast to be coated with apatite by a classical biomimetic process (e.g., PGA) could be coated with bonelike apatite in an accelerated biomimetic process.

Apatites↗
PubMed2005

The mouse chorionic gonadotropin beta-subunit-like (muCG beta l) molecule produced by tumor cells elicits the switch of T-cell immunity response from TH2 to TH1 in mice immunized with DNA vaccine based on rhesus monkey homologous CG beta (rmCG beta).

BACKGROUND: CG beta is expressed not only in placenta, but also in a wide range of tumors. To study DNA vaccine based on xenogeneic CG beta for cancer immuno-therapy, we investigated whether rhesus monkey CG beta (rmCG beta) DNA vaccine could induce protective T-cell responses and humoral responses in mouse. METHODS: We constructed a plasmid containing the rmCG beta coding sequence. Two cloned syngeneic SP2/0 myeloma cell lines that stably express muCG beta l (SP2/0-muCG beta l) and HN (SP2/0-HN) protein were established. Inoculation of these cell lines was made into mice that had been immunized with DNA vaccine. Specific IgG and IgG type were measured by ELISA and the cytokine expression was detected with RT-PCR. To measure the lymphocyte metabolic activity, the MTS assay was used. RESULTS: After injection of SP2/0-muCG beta l into mice that had been immunized with DNA vaccine, a significant increase in the IgG2a specific to the antigen (p < 0.05) and a decrease in the specific IgG1 (p < 0.05) were measured. The expression of T(H)1 but not T(H)2 cytokines, including IFN-gamma and IL-2, were detected in the splenocytes. However, injection of tumor cells expressing irrelevant or mock molecules into immunized mice could not induce these changes. The survival rate of vaccine-immunized mice injected with SP2/0-muCG beta l was as high as 58.3% after 55 days. CONCLUSIONS: The rmCG beta DNA vaccine has proved to be a potential strategy for protection against tumors with homologous molecules. The muCG beta l produced by tumors is able to elicit an immunity switch from T(H)2 to T(H)1 in vaccinated mice.

Animals↗
PubMed2005

Determination of lafutidine in human plasma by high-performance liquid chromatography-electrospray ionization mass spectrometry: application to a bioequivalence study.

A rapid, sensitive and specific high-performance liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) method was developed and validated for the first time to determine the concentration of lafutidine in human plasma. After the addition of diazepam (the internal standard, IS) and 1 M sodium hydroxide solution to 0.5-ml plasma sample, lafutidine was extracted from plasma with n-hexane : isopropanol (95 : 5, v/v). The organic layer was evaporated and the residue was redissolved in 200-microl mobile phase. The analyte was chromatographically separated on a prepacked Shimadzu Shim-pack VP-ODS C(18) column (250 x 2.0 mm i.d.) using a mixture of methanol-water (20 mM CH(3)COONH(4)) = 80 : 20 (v/v) as mobile phase. Detection was performed on a single quadrupole mass spectrometer using an electrospray ionization interface and the selected-ion monitoring (SIM) mode. The method showed excellent linearity (r = 0.9993) over the concentration range of 5-400 ng/ml and had good accuracy and precision. The within- and between-batch precisions were within 10% relative standard deviation. The limit of detection was 1 ng/ml. The validated LC/ESI-MS method has been successfully applied to the bioequivalence study of lafutidine in 24 healthy male Chinese volunteers.

Acetamides↗
PubMed2005

Quantitative gene expression analysis by cDNA microarray during liver regeneration after partial hepatectomy in rats.

PURPOSE: It is speculated that genetic regulation plays an important role during liver regeneration. We conducted this study to analyze quantitative gene expression during liver regeneration after partial hepatectomy. METHODS: Sixty male Wistar rats were randomly assigned into ten groups of six. One group of rats was killed preoperatively and the other nine groups were killed 2, 4, 6, 12, 24, 48, and 72 h, and 5 and 7 days after 70% partial hepatectomy, respectively. The remnant livers were isolated for mRNA extraction. A mass survey of gene expression by cDNA microarray carrying 6144 polymerase chain reaction-amplified cDNA fragments was prepared by an arraying machine. The microarray images were scanned, digitized, and analyzed using a flatbed scanner. RESULTS: The variations in gene expression were classified into 72 different patterns including a pattern with a single peak, 2, 4, 6, 12, and 72 h, and 5 and 7 days after partial hepatectomy. The other patterns included double peaks, enhancing trend, diminished trend, protruding curve, excavated curve, and various mixed types. Each category of gene expression pattern contained 40-218 different proto-oncogenes. CONCLUSION: The quantitative gene expression profiles have important implications, warranting further investigation of the genetic mechanisms involved in the process of liver regeneration.

Animals↗
PubMed2005

Cervical dumbbell meningioma and thoracic dumbbell schwannoma in a patient with neurofibromatosis.

The occurrence of both dumbbell meningioma and dumbbell schwannoma in one patient has not been reported in the literature. We present a 16-year-old female patient, who had progressive bilateral hearing impairment for 5 years and a progressively enlarged, non-tender neck mass for 1.5 years. Mild motor weakness over her right upper limb was noted 1 week before admission. No café-au-lait spot was noted. Magnetic resonance imaging (MRI) revealed bilateral cerebellopontine angle tumors, a C1-2 dumbbell tumor, and a T5-6 dumbbell tumor. Neurofibromatosis type 2 was diagnosed. The cervical spine and thoracic spine tumors were removed via one-staged combined posterior (laminectomy) and antero-lateral (transforaminal or thoracoscopic) approaches during two operations performed 1 month apart. The pathology revealed meningioma and schwannoma, respectively. The patient had good recovery after these two operations and her motor function improved. Six months after the second surgery, radiosurgery was performed for the bilateral acoustic tumors, because of enlarged tumor size on follow-up MRI. To the best of our knowledge, this is the first case reported in the literature of a patient, having both dumbbell meningioma and dumbbell schwannoma. A literature review of the dumbbell tumors was done, and their treatment strategies were discussed.

Adolescent↗
PubMed2005

[Natural occurrence of citrinin in Monascus products].

OBJECTIVE: In order to survey the natural occurrence of citrinin in Monascus products. METHODS: A total of 114 samples with either solid or liquid phases, collected from markets or delivered by the food production factories were analyzed by HPLC for citrinin. RESULTS: The results revealed that 68 (59.65%) samples were positive for citrinin with the levels between 0.18 and 1739.23 mg/kg (211.61 mg/kg for the average and 6.62 mg/kg for the median, respectively). The concentration of cirtrinin in various Monascus products is different. Twenty-five red pigment samples of Monascus were heavily contaminated with citrinin at the level ranged from 0.85 - 1739.93 mg/kg (average 508.40 mg/kg, median 169.88 mg/kg). Twelve of 19 red rice samples fermented by Monoscus species were not citrinin-free but 83.33% (10/12) with the citrinin levels below 10 mg/kg. The level of citrinin in 84% (21/25) health meals of Monascus is less than 6 mg/kg. CONCLUSION: The domestic Monascus products were contaminated by citrinin and the ratio of color value/citrinin in 15 (13.16%) samples exceeds the Japanese national standard.

Biological Products↗
PubMed2005

[Expression of nerve growth factor in cavernous tissue and its effects on the treatment of rats with diabetic erectile dysfunction].

OBJECTIVE: To investigate the content of nerve growth factor (NGF) in penis of rats with diabetic erectile dysfunction (DED) and apply rhNGF to treat the DED rat model to study the pathogenesis mechanism of DED and treatment effects by NGF for DED rat model. METHODS: Fifty adult male SD rats were randomly selected to make up diabetic models. After 8 weeks, the mRNA and protein levels of NGF in rat penis were detected. Then the rest of rats were divided into 5 groups: normal control group, non-treated diabetes group, NGF treatment group, insulin treatment group, NGF plus insulin treatment group. After 8 weeks of treatment, intracavernous pressure (ICP) was measured. The content of neuronal nitric oxide synthase (nNOS) in the erectile tissue was also value- ated by immunohistochemistry staining. RESULTS: Compared with those of normal control group, the mRNA content of NGF and protein in the penis of non-treated diabetic rats is increased significantly. Compared with non-treated diabetic group, ICP was much higher in the treated groups which received NGF or/and insulin therapy, and the changes in nNOS staining of those groups were the same. CONCLUSION: The injury of pelvic splanchnic nerves in advanced stage of diabetes may lead to DED, which may be relevant to the abnormal of NGF level or the NGF receptors. The increased extent of NGF in penis of rat with DED suggests that erectile nerves be severely damaged by diabete and the increase of producing NGF couldn't compensate the needs for reproduction of the nerve fibers. The ability of combination of NGF with its receptor may also be damaged. It is helpful to use exogenous NGF to lessen the partly neuropathy and improve the erectile dysfunction of diabetic rats. The abnormal of NGF may play an important role in the pathogenesis of diabetic ED and its treatment.

Animals↗
PubMed2005

[Synchronization of the activity of gamma oscillation and ERP components].

In the present study the activity of the gamma oscillation synchronized with the stimuli and ERP is investigated by means of unimodal and bimodal experiments. The multiresolution wavelet algorithm is used for signal extraction and Gabor transform is employed to represent the temporal evolution of the selected frequency components. The results show that the gamma oscillation is strongly phase-locked not only with the exogenous stimuli in the three experiments, but also with the endogenous components of ERPs (N2b, P300). And the ERP and the gamma oscillation induced by the bimodal stimuli show the audio-visual bisensory integration and relationship. In addition, the results from the experiments with the auditory stimuli show that the gamma oscillation may be closely related to the perception of auditory signals.

Adult↗
PubMed2005

[Spectroscopic studies on the interaction of nicotine and BSA].

The interaction of nicotine and bovine serum albumin(BSA) was investigated by fluorescence spectra and UV-vis spectra. The fluorescence spectrum showed that BSA fluorescence quench regularly with the addition of nicotine.The fluorescence quenching mechanisms were also studied in pH 5.0, pH 7.4 and pH 11.0 by Stern-Volmer equation, indicating dynamic quenching(pH 5.0) and static quenching(pH 7.4 and pH 11.0) respectively. Association constants (k) of nicotine and BSA at pH 7.4 and pH 11.0 at the temperatures of 20 and 37 degrees C were given by the Lineweaver-Buck equation, which are: k(20 degrees C) = 140.15 L x mol(-1) and k(37 degrees C) = 131.83 mol x L(-1) (pH 7.4), and k(20 degrees C) = 141.76 mol x L(-1), k(37 degrees C) = 27.79 mol x L(-1) (pH 11.0), suggesting that the association constant is effected by the temperature much more remarkably at pH 7.4 than that at pH 11.0 because of the different states of nicotine at different pHs. The UV-Vis spectra exhibit that the absorbance of BSA(210 nm) shifts to red and decreases gradually with the addition of nicotine, reflecting the transition of secondary structure of BSA, namely, the helix of BSA becomes looser. The UV-Vis second derivative spectra and synchronous spectra (delta wavelength = wavelength(em) - wavelength(ex) = 15 nm and delta wavelength = wavelength(em) - wavelength(ex) = 60 nm) imply the change of the microcircumstance of aromatic amino residues of BSA(Trp, Tyr and Phe) from hydrophobicity to hydrophilicity at high concentration of nicotine.

Animals↗
PubMed2005

Cell saver does not increase pro-inflammatory cytokine levels and expression of adhesive molecules in the salvaged blood of patients undergoing off-pump coronary artery bypass surgery.

BACKGROUND: Autotransfusion has been developed to avoid the risks of contaminating with infectious diseases and susceptivity to other complications of allogeneic blood transfusion. Previous studies have shown significant pro-inflammatory cytokine release and complement activation during blood salvage with cell saver (CS) in the course of on-pump coronary artery bypass grafting (CABG) surgery. Because both extracorporeal pump and CS machine are possible to induce the adverse cytokines release, thus, in this study, we investigated the influence of CS alone on the levels of pro-inflammatory cytokines and the expression of leukocyte surface antigens in patients undergoing off-pump CABG. METHODS: Thirty patients proposed to undergo off-pump CABG were enrolled in this study. Five perioperative blood samples (peripheral blood before operation, blood in pericardial sac at operation, blood in the cell saver container, blood in the blood bag before transfusion, and peripheral blood one hour after operation) were obtained from each patient. The expression of activated leukocyte adhesive molecules (CD11b and CD18) and cytokine-inducible leukocyte-endothelial adhesive molecule (CD62P) were studied by flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was conducted to determine the levels of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and IL-8. RESULTS: All blood samples except the one obtained one hour after operation showed no difference of the expression of CD11b, and CD62P and the levels of TNF-alpha, IL-6 and IL-8 (P> 0.05). However, the expression of CD18 was decreased during the course of blood salvage. The peripheral blood obtained one hour after operation had significantly higher expression of the three tested leukocyte surface antigens and higher levels of three studied cytokines (P < 0.05). CONCLUSIONS: Our investigation indicated that the blood processing in cell saver alone did not increase the expression of either CD11b, CD18, or CD62P, and the levels of TNF-alpha, IL-6 and IL-8. The results suggest that cell saver seems not to significantly activate the leukocytes or cause inflammatory responses in the salvaged blood.

Adult↗
PubMed2004

Sylvian fissure dermoid cyst with intratumoral hemorrhage: case report.

It is rare for a dermoid cyst to develop intratumoral hemorrhage. A 61-year-old woman had a sudden-onset left hemiparesis and slow response to verbal requests for one week when unenhanced computed tomography scanning revealed a mixed iso- and hypo-dense heterogeneous lesion in the right fronto-temporal area. T1-weighted magnetic resonance imaging (MRI) of the brain showed a mixed hyper- and hypo-intense tumor in the right fronto-temporal area. The tumor became hyperintense on T2-weighted MRI and was faintly enhanced at tumor periphery on T1-weighted MRI. The tumor was excised and pathological examination revealed a dermoid cyst with intratumoral hemorrhage. The post-operative course was complicated by hemorrhage in the tumor bed, which was evacuated immediately. The patient improved and could walk without support two weeks after the second operation. After 1 year of follow-up, she was well and without neurological deficits. To the best of our knowledge after a literature review, only two previous cases of dermoid cyst have featured intratumoral hemorrhage.

Brain Stem Neoplasms↗