Malignant potential of neuroendocrine microtumor of the pancreas harboring high-grade transformation: lesson learned from a patient with von Hippel-Lindau syndrome

Pancreatic neuroendocrine microtumor (PNEMT) is a neuroendocrine tumor (NET) < 0.5 cm in diameter, and it is considered benign. We report a PNEMT with high-grade transformation (HGT). A man in his 60s with von Hippel-Lindau syndrome underwent surgical resection of a NET. A second sub-centimeter nodule with a nodule-in-nodule pattern was discovered. The 0.4 cm outer nodule contained clear columnar cells with round nuclei and indistinct nucleoli, while the 0.1 cm inner nodule had eosinophilic cells with an increased nuclear to cytoplasmic ratio, vesicular nuclei, and prominent nucleoli. Tumor cells in the outer and inner nodules were synaptophysin and chromogranin positive. Only the inner nodule was p53 positive, while the outer nodule was exclusively positive for carbonic anhydrase 9 and vimentin. The Ki-67 labeling indices for the outer and inner nodules were 2.1% (grade 1) and 44.3% (grade 3), respectively. This nodule was determined to be a PNEMT with HGT. Our findings suggest that a PNEMT may not always be benign and can undergo HGT.

Releasing of a Titanium Clamp (Craniofix®) Without Mechanical Defect After Craniotomy for Acute Subdural Hemorrhage / 대한신경손상학회지

After craniotomy, bone flap fixation can be performed using wires, sutures, microplates, and Craniofix®. Well-margined and fixed bone flaps are important not only for postoperative brain protection but also for esthetics. Herein, we report a case of cranioplasty due to bone flap dislocation by Craniofix® clamp loosening after craniotomy with acute subdural hemorrhage removal. Iatrogenic outward force during epidural drain removal adjacent to Craniofix®, insertion of the clamp around the circumference of the bone flap, increased intracranial pressure due to brain swelling and fluid collection, and external shock during postoperative patient management are thought to be the causes of bone flap dislocation. To our knowledge, this is the second reported case of craniotomy with a Craniofix® clamp release.

Extremely well-differentiated adenocarcinoma of the stomach: diagnostic pitfalls in endoscopic biopsy

Background@#Extremely well-differentiated adenocarcinoma (EWDA) is a deceptively bland-looking adenocarcinoma of the stomach. It often causes diagnostic problems, especially in endoscopic biopsy samples. To better recognize this deceptively bland lesion, we carefully reviewed a series of EWDAs treated at our institution. @*Methods@#A total of 55 specimens from 19 patients were obtained. Endoscopic, gross and microscopic features defining EWDA were described and documented. For comparison, hyperplastic polyp specimens were randomly selected and analyzed. @*Results@#Most cases (18 of 19, 94.7%) were advanced gastric cancer (AGC) and primarily located in the body of the stomach (15 of 19, 79.0%). The majority of AGCs were non-ulcerated (11 of 18, 61.1%) with an undermining growth pattern and a relatively small mucosal involvement. Specific histologic features included an irregular glandular shape, an undulating apical cytoplasmic border, disproportionately large glands, a variably distended mucinous cytoplasm. Classical features, such as small infiltrating glands or desmoplastic reactions, were barely observed. Identification of irregularly spaced nuclei and disruption of the foveolar epithelial structure, along with atypical features described above were helpful in making a diagnosis especially in gastric forceps biopsies. @*Conclusions@#Awareness of the histomorphologic characteristics described in this report would lead to timely diagnosis and prevent repeated endoscopic procedures.

Supplementation with psyllium seed husk reduces myocardial damage in a rat model of ischemia/reperfusion

BACKGROUND/OBJECTIVES: Myocardial infarction (MI) is caused by extensive myocardial damage attributed to the occlusion of coronary arteries. Our previous study in a rat model of ischemia/reperfusion (I/R) demonstrated that administration of arabinoxylan (AX), comprising arabinose and xylose, protects against myocardial injury. In this study, we undertook to investigate whether psyllium seed husk (PSH), a safe dietary fiber containing a high level of AX (> 50%), also imparts protection against myocardial injury in the same rat model. MATERIALS/METHODS: Rats were fed diets supplemented with PSH (1, 10, or 100 mg/kg/d) for 3 d. The rats were then subjected to 30 min ischemia through ligation of the left anterior descending coronary artery, followed by 3 h reperfusion through release of the ligation. The hearts were harvested and cut into four slices. To assess infarct size (IS), an index representing heart damage, the slices were stained with 2,3,5-triphenyltetrazolium chloride (TTC). To elucidate underlying mechanisms, Western blotting was performed for the slices. RESULTS: Supplementation with 10 or 100 mg/kg/d of PSH significantly reduces the IS. PSH supplementation (100 mg/kg/d) tends to reduce caspase-3 generation and increase BCL-2/BAX ratio. PSH supplementation also upregulates the expression of nuclear factor erythroid 2-related factor 2 (NRF2), and its target genes including antioxidant enzymes such as glutathione S-transferase mu 2 (GSTM2) and superoxide dismutase 2 (SOD2). PSH supplementation upregulates some sirtuins (NAD+-dependent deacetylases) including SIRT5 (a mitochondrial sirtuin) and SIRT6 and SIRT7 (nuclear sirtuins). Finally, PSH supplementation upregulates the expression of protein kinase A (PKA), and increases phosphorylated cAMP response element-binding protein (CREB) (pCREB), a target protein of PKA. CONCLUSIONS: The results from this study indicate that PSH consumption reduces myocardial I/R injury in rats by inhibiting the apoptotic cascades through modulation of gene expression of several genes located upstream of apoptosis. Therefore, we believe that PSH can be developed as a functional food that would be beneficial in the prevention of MI.

Protection of the brain through supplementation with larch arabinogalactan in a rat model of vascular dementia

BACKGROUND/OBJECTIVES: Vascular dementia (VaD) caused by reduced blood supply to the brain manifests as white matter lesions accompanying demyelination and glial activation. We previously showed that arabinoxylan consisting of arabinose and xylose, and arabinose itself attenuated white matter injury in a rat model of VaD. Here, we investigated whether larch arabinogalactan (LAG) consisting of arabinose and galactose could also reduce white matter injury. MATERIALS/METHODS: We used a rat model of bilateral common carotid artery occlusion (BCCAO), in which the bilateral common carotid arteries were exposed and ligated permanently with silk sutures. The rats were fed a modified AIN-93G diet supplemented with LAG (100 mg/kg/day) for 5 days before and 4 weeks after being subjected to BCCAO. Four weeks after BCCAO, the pupillary light reflex (PLR) was measured to assess functional consequences of injury in the corpus callosum (cc). Additionally, Luxol fast blue staining and immunohistochemical staining were conducted to assess white matter injury, and astrocytic and microglial activation, respectively. RESULTS: We showed that white matter injury in the the cc and optic tract (opt) was attenuated in rats fed diet supplemented with LAG. Functional consequences of injury reduction in the opt manifested as improved PLR. Overall, these findings indicate that LAG intake protects against white matter injury through inhibition of glial activation. CONCLUSIONS: The results of this study support our hypothesis that cell wall polysaccharides consisting of arabinose are effective at protecting white matter injury, regardless of their origin. Moreover, LAG has the potential for development as a functional food to prevent vascular dementia.

Oncologic Effect of Oral Fluorouracil in Hormone Receptor-Negative T1a Node-Negative Breast Cancer Patients

PURPOSE: As 5-fluorouracil (5-FU) has previously exhibited antitumor activity and few adverse effects in the treatment of breast cancer, we aimed to specifically assess the benefits of orally administered 5-FU in hormone receptor-negative small breast cancer. METHODS: We retrospectively identified patients with pT1aN0 and hormone receptor-negative breast cancer who underwent surgery between 1993 and 2008 at Asan Medical Center. Patients were divided into two cohorts based on adjuvant doxifluridine (Didox; Shin Poong Pharm. Co., Ltd.) administration, and the disease-free survival (DFS) and cancer-specific survival (CSS) was assessed for each cohort. RESULTS: Both cohorts had similar ages and tumor sizes. The DFS and CSS did not significantly differ between the groups (p=0.399 and p=0.126, respectively). When the cohorts were assessed according to human epidermal growth factor receptor 2 (HER2) status, doxifluridine significantly improved DFS among patients with T1aN0 and HER2-positive breast cancer (p=0.037). CONCLUSION: Doxifluridine did not yield a significant reduction in DFS events in hormone receptor-negative early breast cancer. However, a clear benefit was observed in hormone receptor-negative, HER2-positive T1aN0 breast cancer patients.

Psychometric Properties of a Measure Assessing Attitudes and Norms as Determinants of Intention to Use Oral Contraceptives

PURPOSE: Asian immigrant and Asian American women are less likely to use oral contraceptives (OCs) and tend to rely on low-efficacy methods of contraception. This contraceptive pattern remains poorly understood, in part, because no theory-driven measurement exists to assess psychosocial determinants essential in explaining behaviors related to OC use in this population. The current study aimed to evaluate the psychometric properties of a measure of attitudes and subjective norms toward OC use among Korean American women as a first step to determine whether the measure can be used in this population and, potentially, in other Asian ethnic groups. METHODS: The sample consisted of 329 Korean immigrant women living in New York City. The theory of reasoned action guided the development of the measure assessing attitudes and norms. Psychometric evaluation included item analysis, internal consistency estimates of reliability, and construct validity (i.e., factorial, discriminant, and predictive). RESULTS: All item-total correlations were above the recommendation of .30. The Cronbach's alpha for the attitudes and subjective norms measure was .88 and .86, respectively. Exploratory factor analyses revealed four interpretable factors, and confirmatory factor analyses confirmed that the factor structures derived from the exploratory factor analyses fit the data well. Discriminant and predictive validity of the measure were also established. CONCLUSIONS: The study provides support for the validity and reliability of the measure and its use for determining the degree to which Korean immigrant women intend to use OCs.

Protective Effect of Arabinoxylan against Scopolamine-Induced Learning and Memory Impairment

The purpose of this study is to investigate the memory enhancing effect and underlying molecular mechanism of arabinoxylan (AX), a major component of dietary fiber in wheat against scopolamine (SCO)-induced amnesia in Sprague-Dawley (SD) rats. Diverse behavior tests including Y-maze, Morris water maze, and passive avoidance tests were performed to measure cognitive functions. SCO significantly decreased the spontaneous alterations in Y-maze test and step-through latency in passive avoidance test, whereas increased time spent to find the hidden platform in Morris water maze test compared with the sham control group. In contrast, oral administration of AX (25 mg/kg and 50 mg/kg) effectively reversed the SCO-induced cognitive impairments in SD rats. Furthermore, AX treatment up-regulated the expression of brain-derived neurotrophic factor (BDNF) in the cortex and hippo-campus via promoting activation of cAMP response element binding protein (CREB). Therefore, our findings suggest that AX can improve SCO-induced learning and memory impairment possibly through activation of CREB and up-regulation of BDNF levels, thereby exhibiting a cognition-enhancing potential.

Apple pectin, a dietary fiber, ameliorates myocardial injury by inhibiting apoptosis in a rat model of ischemia/reperfusion

BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.

Apple pectin, a dietary fiber, ameliorates myocardial injury by inhibiting apoptosis in a rat model of ischemia/reperfusion

BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.

Effects of feminine cleanser Inclear on sperm motility: A prospective study / 대한생식의학회지

OBJECTIVE: The objective of this study is to estimate the effects of Inclear, a feminine cleanser, on sperm motility. METHODS: Semen samples were obtained from infertile male patients. Following liquefaction, the raw semen samples were diluted with Ham's F-10 nutrient mixture medium containing 0.4% human serum albumin solution at a ratio of 1:3. The semen samples were subsequently centrifuged to separate the seminal plasma from the serum. The supernatant was discarded, and the pellet was resuspended. The sample was again centrifuged to remove cell debris, and the supernatant was removed. The final pellet was gently loosened by resuspension and incubated in medium alone as a control, and in a 10% solution of the medium plus Inclear. A sampling time of 30 minutes was selected on the basis of sperm transport studies. Sperm motility was evaluated with computer-assisted sperm analysis. RESULTS: A total of 20 samples were analyzed. The mean age of patients was 34.40+/-2.96 years. There was no difference in sperm concentration and motility in the two samples at 0 minute and 30 minutes of incubation. In both semen samples, the sperm concentration and motility decreased after an incubation period of 30 minutes. However, there was no statistical difference between the samples. Sperm concentration and motility were not significantly different between the control and Inclear samples after 0 minute and 30 minutes of incubation. CONCLUSION: Inclear has no negative effects on sperm motility. This product can be recommended to pregnancy planners for vaginal hygiene and as a vaginal lubricant.

Influence of Early Childhood Care and Education on Children's Mental Health (I) - Status and Prospects of Child Care and Education Policies of Korea -

Most preschool children in Korea attend kindergarten (KG) or a child care center (CCC). CCCs, which focus on caring for the child, belong to the ministry of health and welfare. On the other hand, KGs are responsible for education, and belong to the ministry of education, science and technology. In order to resolve the decline in population due to low birthrates, the government is expanding the free child care and education policies. CCCs and KGs are combined together to form the 'NURI curriculum' and supporting funds have been increased in both governmental departments. In addition, economic support is provided for homeschooling households. Because this is a nationwide policy and applies to every single household, thorough preparation regarding the effect and side effects must be made. This policy is currently being implemented, and as child and adolescent psychiatrists, great consideration should be given to the influence on the population. Therefore, the Korean Academy of Child and Adolescent Psychiatry intends to investigate the effects and problems of the nationwide policy by analyzing the current condition of Korea's free child care and education and foreign policies. In the current paper, we reviewed the developmental process of Korea's free child care and education policy, as well as suggested future directions.

The Effect of Extract of Paeonia lactiflora on the Improvement of Ischemic Acute Renal Failure / 대한신장학회지

PURPOSE:The present study was undertaken to investigate whether the extract or the ethyl acetate fraction of Paeonia lactiflora, which improves cell survival under ischemic condition by inhibiting apoptosis, can prevent ischemic acute renal failure, using rats as an animal model. METHODS:In the control group, ischemia/reperfusion (I/R) injury was induced in male Sprague-Dawley rats by clamping of left renal pedicle for 45 minutes after removal of the right kidney, and subsequent reperfusion of the pedicle for 24 hours. In the experimental group, the water extract or ethyl acetate fraction of methanol extract Paeonia lactiflora was injected 1 hour prior to ischemia/reperfusion injury. We measured serum concentrations of creatinine at 24 hours after I/R injury. And the kidneys were extracted, fixed in a 10 % neutral-buffered formalin solution, embedded in paraffin and used for histopathological examination. RESULTS:Rats in the experimental group, treated with water extract or ethyl acetate fraction of methanol extract of Paeonia lactiflora, exhibited significant decrease in the serum concentrations of creatinine (approx. 2.0 mg/dL), compared with those in the control group (approx. 4.0 mg/dL). Finally, the cell morphology of the kidney of rats treated with ethyl acetate fraction of Paeonia lactiflora was well preserved, when judged from histopathological point of view. CONCLUSION:Pretreatment of rats with the water extract or ethyl acetate fraction of Paeonia lactiflora might be beneficial for the treatment of acute renal failure in humans.

Effect of Combination of Anticancer Agents and Nitroimidazoles on the Survival of Human Hepatocellular Carcinoma Cells under Hypoxic Conditions

PURPOSE: In a previous study, we have shown that anticancer agents inhibiting topoisomerases improve survival of tumor cells under hypoxic condition. In the present study, we evaluated whether and how cell survival effect of the anticancer agents under hypoxic conditions could be eliminated by the addition of nitroimidazoles, a class of bioreductive agents. METHODS: Human hepatocellular carcinoma cells (HepG2) were incubated with different combinations of pimonidazole (1~1,000 microg/ml) and doxorubicin (0.1 or 1 microg/ml) concentrations under different O2 concentrations [1, 3, 5, 10 and 21 O2]. Then cell numbers, glucose concentrations and lactic acid concentrations in the medium were measured, and DNA fragmentation assay was performed. Finally, different combinations of nitroimidazoles, such as pimonidazole, misonidazole, etanidazole, tinidazole, metronidazole, ornidazole or dimetridazole, and anticancer agents, such as doxorubicin, campothecin, epirubicin, dactinomycin, etoposide or mitomycin C was added to the cell culture medium under hypoxic conditions (1% O2). RESULTS: Pimonidazole at a concentration of 100 microg/ml eliminated cell survival effect of doxorubicin at the concentrations of 0.1 and 1 microg/ml under hypoxic condition (1% O2) by promoting apoptosis. Almost all the cells died even after 24 hours of incubation for all the oxygen concentrations at a combination of 100 microg/ml pimonidazole and 1 microg/ml doxorubicin. Finally, pimonidazole at a concentration of 100 microg/ml, and misonidazole or etanidazole at a concentration of 1,000 microg/ml eliminated cell survival effect of all the anticancer agents tested under hypoxic condition. CONCLUSION: Combination therapy of doxorubicin (adriamycin) with pimonidazole can maximize dororubicin efficacy by eliminating cell survival effect of doxorubicin under hypoxic conditions in treating solid tumors, such as breast cancer.

Effect of antitumor agents on the survival of human hepatocellular carcinoma cells under hypoxic conditions / 대한내과학회지

BACKGROUND: In a previous study, we have shown that quinolones, antibiotics inhibiting topoisomerases, improve survival of tumor cells under hypoxic conditions. In this study, we tested whether antitumor agents such as doxorubicin that inhibit topoisomerases can also improve survival of tumor cells under hypoxic conditions. METHODS: Human hepatocellular carcinoma cells (HepG2) were grown in 4 mL of the culture medium at 2.5x10(5) cells/60 mm culture dish under normoxic conditions for 2 days before being transferred to fresh culture medium with different concentrations of doxorubicin or other antitumor agents under normoxic or hypoxic (1% oxygen concentration in air) conditions. Cell viability and the concentration of glucose and lactic acid in the medium were measured during cell culture. At the same time, the cells in the 60 mm dishes were lysed, and chromosomal DNA was isolated and loaded onto a 1.5% agarose gel for the DNA fragmentation assay. RESULTS: Doxorubicin inhibited cell growth under normoxic condition in a concentration-dependent manner for the 0~100 microgram/mL concentration range. However, doxorubicin improved cell viability under hypoxic conditions for a 0.1~10 microgram/mL concentration range by inhibiting apoptosis. Similar phenomena were observed for other antitumor agents that inhibit topoisomerases. CONCLUSIONS: Solid tumors usually have hypoxic regions in the tumor, under which conditions antitumor agents that inhibit topoisomerases may function to delay tumor cell death. This can reduce the efficacy of the antitumor agents.

Effect of Antibiotics on the Survival of Human Hepatocellular Carcinoma Cells under Hypoxic Conditions

PURPOSE: Antibiotics that kill or suppress the growth of bacteria also affect tumors directly or indirectly. The authors aimed to show whether some antibiotics can improve cancer cell survival under hypoxic conditions, and how the antibiotics improve the cells under hypoxic conditions. METHODS: Human hepatocellular carcinoma cells (HepG2) were grown at 1% oxygen concentration. Cell numbers, glucose concentrations and lactic acid concentrations in the medium were measured at different incubation times, in the absence or presence of aminoglycosides, tetracyclines, quinolones, penicillins, cephalosporins, sulfonamides, or chloramphenicols. DNA fragmentation assay was performed to study the mechanism how some antibiotics improve the cell survival under hypoxic conditions. RESULTS: Of the antibiotics tested, only aminoglycosides, tetracyclines, quinolones and the chloramphenicol improved cell survival under hypoxic conditions. Geneticin (G418), an aminoglycoside chosen as an example, improved cell survival even if glucose in the medium was completely consumed. At the same time, the appearance of DNA ladder was delayed in the presence of geneticin, which was also the same for the other antibiotics that improved cell survival under hypoxic conditions. CONCLUSION: Some antibiotics improved hepatocellular carcinoma cells under ischemic conditions by inhibiting apoptosis. The results implies that the antibiotics might adversely affect solid tumors, by improving cancer cell growth where hypoxic or ischemic conditions occur in the core region. Therefore, we might be cautious in choosing antibiotics for cancer patients with solid tumors, especially when the patients should be treated with antibiotics for a long time.

The Effects of Dexamethasone, 6 alpha-Methylprednisolone, and Retinoic Acid on the Growth and Morphology of a Rat Glioma Cell Line, C6

Glucocorticoids, dexamethasone, 6 alpha-methylprednisolone are routinely administered to brain tumor patients to reduce peritumoral edema before surgical removal of the tumor. In addition, the glucocorticoids can inhibit growth of several cell lines. Retinoic acid, a derivative of vitamin A is also known to inhibit growth of several cell lines. Sometimes inhibition of growth accompany morphological changes. In the present study, we compared the effects of dexamethasone, 6 alpha-methylprednisolone, and retinoic acid on the growth and on the morphology of a rat glioma cell line, C6. We found that all of them can maximally inhibit the growth of C6 by approximately 30%(p<0.0025) in the presence of 10 microM of either dexamethasone, 6 alpha-methylprednisolone or retinoic acid under our experimental conditions. However, only retinoic acid could induce the morphological changes of C6 at the concentrations over 1 microM concentration, which was elongation of the cells. The morphological changes were observed both at the subconfluent and confluent cell population. When mixture of 10 microM of dexamethasone and 10 microM of retinoic acid was added, no further increase in the inhibition of growth was observed compared with the inhibition obtained by adding 10 microM of dexamethasone only. The results suggest that the glucocorticoids might have effedts of growth inhibition of the glial tumor in vivo.