Effects of NMDA receptor inhibition by phencyclidine on the neuronal differentiation of PC12 cells

Phencyclidine (PCP) is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist and exposing the developing brain to PCP has been shown to cause deficits in neurobehavioral functions. In the present study we tested the effects of PCP, as an NMDA receptor inhibitor, on the neuronal differentiation and biogenic amines levels including norepinephrine (NE), epinephrine, dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) in the rat pheochromocytoma (PC12) cells. After PC12 cells were differentiated with nerve growth factor (NGF) in the presence of PCP, NMDA binding kinetics, biogenic amines analysis and NMDA receptor protein expression assay were conducted. The results showed that NMDA receptor binding activities were significantly increased after differentiated with NGF in PC12 cells. B(max) values were increased in differentiated cells by four-folds, whereas K(d) values were not changed. All of biogenic amines were significantly increased in differentiated cells. On the other hand, PCP at 50 and 100 microM inhibited neuronal differentiation in a dose-dependent manner in NGF-stimulated PC12 cells without affecting cell viability. PCP treatment during differentiation significantly reduced NMDA binding activity and biogenic amine levels. Western blotting analysis revealed that NMDA receptor protein expression was significantly higher in NGF-differentiated cells and PCP treatment decreased the expression of NMDA receptor proteins. These results indicate that NMDA receptor functions and monoaminergic nervous systems are significantly stimulated during NGF-induced differentiation. PCP suppresses neuronal outgrowth and hampers neuronal functions possibly by inhibiting NMDA receptor functions and biogenic amine production, implying the suppressive effects of PCP exposure on neuronal developments.     

Differential expression of vascular endothelial growth factor and its receptors in hematopoietic and fatty bone marrow: evidence that neuropilin-1 is produced by fat cells

Vascular endothelial growth factor (VEGF), its receptors (VEGFR-1, VEGFR-2) and neuropillin-1 (NRP-1) are expressed at variable levels in bone marrow. NRP-1expression is higher in fatty bone marrow than in hematopoietic marrow. Adipocytes are responsible for NRP-1 expression suggesting that they may play a role in hematopoiesis by producing NRP-1 or that NRP-1 may regulate adipocyte activity.     

Dietary and other risk factors in women having fibrocystic breast conditions with and without concurrent breast cancer: a nested case-control study in Shanghai, China

Risk of breast cancer is increased in women with proliferative benign breast conditions. Most of these conditions, however, do not progress to breast cancer. The purpose of our study was to identify factors possibly associated with this progression. Women with proliferative fibrocystic breast conditions alone (214), and women with proliferative fibrocystic breast conditions and concurrent breast cancer (130), were compared to each other, and each of these groups of women were also compared to 1,070 controls; and 176 women with non-proliferative benign breast conditions alone, and 155 also with breast cancer, were similarly compared. All study subjects were selected from a cohort of women enrolled in a trial of breast self-examination in Shanghai. Women were interviewed to ascertain information on suspected risk factors for breast cancer and dietary habits. Conditional logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI). Increased risks of both proliferative fibrocystic breast conditions alone, and with breast cancer, were associated with low parity, a prior benign breast lump and breast cancer in a first-degree relative. Decreasing trends in the risk of both conditions with increasing intake of fruits and vegetables were observed. No factors were significantly associated with risk of breast cancer relative to risk of proliferative changes. Similar, but in some instances weaker, associations were observed for non-proliferative fibrocystic conditions with and without breast cancer. The possible risk or protective factors that were observed in our study most likely alter the risk of breast cancer at an early stage in the carcinogenic process, and probably do not alter risk of progression from proliferative fibrocystic breast conditions to breast cancer.     

Immunohistochemical markers in the diagnosis of papillary thyroid carcinomas: The promising role of combined immunostaining using HBME-1 and CD56

We aimed to evaluate the expression and diagnostic value of five immunohistochemical markers (HBME-1, Galectin-3, CK19, CD56 and p63) in a very large series of unequivocal papillary thyroid carcinoma (PTC) cases, including both the classic (CPTC) and the follicular variant (FVPTC).     

Influence of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene by cucurbits

Field experiments were conducted to determine the impact of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p '-DDE) by eight cultivars of cucurbits over a single growing season. Four cultivars of Cucurbita pepo ssp pepo are accumulators and extract percent level quantities of persistent organic pollutants (POPs), whereas C. pepo ssp ovifera and Cucumis sativus are nonaccumulators. The nonamended accumulators phytoextracted 1.0% of the p,p'-DDE and had a translocation factor of 0.44; however, the nonaccumulators removed 0.16% of the contaminant and had a translocation factor value of 0.09. The accumulators also had 3.8 times greater inorganic element content than the nonaccumulators. Duplicate mounds of each cultivar also received weekly nutrient amendments of phosphorus (400 mg/L K2HPO4), nitrogen (200 mg/L KNO3), or nitrogen/phosphorus (400 mg/L K2HPO4, 200 mg/L KNO3); a minus phosphorus treatment involved a 1-L addition of 1 g/L AlSO4 to the soil before planting. When normalized to respective control values (unamended vegetation), the root and stem p,p'-DDE bioconcentration factors (BCF) of the accumulator cultivars were significantly greater than those of the nonaccumulator cultivars under most nutrient regimes. The biomass of accumulator cultivars decreased by up to 61% under certain nutrient regimes, resulting in mixed effects on the amount of p,p'-DDE extracted. Treatment with N and P increased nonaccumulator biomass by 40 to 100%, and increased p,p'-DDE extraction from soil by 75%. Although generally assumed that fertilizer amendments will enhance phytoremediation, as evidenced here by the nonaccumulators, additions of macronutrients may reduce the phytoextraction of weathered POPs by C. pepo ssp pepo. These findings support our hypothesis that the ability of C. pepo ssp pepo to remove sequestered organic contaminants is governed by unique nutrient-acquisition mechanisms.     

Measles surveillance and control in Tunisia: 1979-2000

BACKGROUND: The aim of this study was to analyze measles epidemiology in Tunisia after the introduction of specific vaccine in 1979 and the results of the serological investigation of suspected cases, introduced as part of the National Program for Measles Elimination recently implemented. METHODS: Available data were used to examine trends in measles epidemiology from 1979 to 2000: number of reported cases, patient's age, reporting date, epidemiological link with similar cases and laboratory confirmation. Serological investigation included the detection, by ELISA, of measles and rubella IgMs in 542 suspected measles cases sampled from 1997 to 2000. RESULTS: Measles coverage level increased gradually and was maintained to over 90% since 1992. In parallel, the annual incidence of reported cases declined and outbreaks became less frequent, the latest occurred in 1992. Measles-specific IgMs were detected in only nine patients who received measles vaccine few days before blood collection, anti-rubella IgMs were detected in 52% of cases. CONCLUSION: Vaccination strategies including routine and supplemental immunizations, implemented in Tunisia, achieved a substantial decrease in measles incidence. Virological results highlight frequent confusion, at the clinical level, with the other etiologies of rash and fever and the importance of systematic serological confirmation of cases.     

Ten-year prospective study (clinical spectrum) of childhood Guillain-Barré syndrome in the Arabian peninsula: comparison of outcome in patients in the pre- and post-intravenous immunoglobulin eras

A prospective study of Guillain-Barré syndrome from January 1992 to December 2001 was undertaken. Intravenous immunoglobulins were used in all patients. All patients were followed up until complete recovery. Various parameters, such as onset of weakness, duration of hospital stay, ventilation requirement, residual deficit, and mortality, were recorded. Acute relapses and fluctuations were also noted. The pattern of this group was compared with patients before 1992, who were not given intravenous immunoglobulins in the Sultanate of Oman. Our data were compared with a few studies prior to 1992 from the medical literature. Our study revealed a definite benefit with intravenous immunoglobulins. The disease course and hospital stay were shortened. Fewer patients needed ventilation. There was no mortality, and the residual deficit was less than 5%. Occasional relapses at a later stage in the course of illness have been noted in acute Guillain-Barré syndrome. However, acute relapse, a new phenomenon that was not seen in the pre-intravenous immunoglobulin era, stood at 11.9%. Intravenous immunoglobulins have made a significant difference in the outcome of Guillain-Barré syndrome, but one has to be aware of acute relapses, which usually occur in the first 2 to 3 weeks after administration.