A multidisciplinary approach unravels early and persistent effects of X-ray exposure at the onset of prenatal neurogenesis

Background

In humans, in utero exposure to ionising radiation results in an increased prevalence of neurological aberrations, such as small head size, mental retardation and decreased IQ levels. Yet, the association between early damaging events and long-term neuronal anomalies remains largely elusive.

Methods

Mice were exposed to different X-ray doses, ranging between 0.0 and 1.0 Gy, at embryonic days (E) 10, 11 or 12 and subjected to behavioural tests at 12 weeks of age. Underlying mechanisms of irradiation at E11 were further unravelled using magnetic resonance imaging (MRI) and spectroscopy, diffusion tensor imaging, gene expression profiling, histology and immunohistochemistry.

Results

Irradiation at the onset of neurogenesis elicited behavioural changes in young adult mice, dependent on the timing of exposure. As locomotor behaviour and hippocampal-dependent spatial learning and memory were most particularly affected after irradiation at E11 with 1.0 Gy, this condition was used for further mechanistic analyses, focusing on the cerebral cortex and hippocampus. A classical p53-mediated apoptotic response was found shortly after exposure. Strikingly, in the neocortex, the majority of apoptotic and microglial cells were residing in the outer layer at 24 h after irradiation, suggesting cell death occurrence in differentiating neurons rather than proliferating cells. Furthermore, total brain volume, cortical thickness and ventricle size were decreased in the irradiated embryos. At 40 weeks of age, MRI showed that the ventricles were enlarged whereas N-acetyl aspartate concentrations and functional anisotropy were reduced in the cortex of the irradiated animals, indicating a decrease in neuronal cell number and persistent neuroinflammation. Finally, in the hippocampus, we revealed a reduction in general neurogenic proliferation and in the amount of Sox2-positive precursors after radiation exposure, although only at a juvenile age.

Conclusions

Our findings provide evidence for a radiation-induced disruption of mouse brain development, resulting in behavioural differences. We propose that alterations in cortical morphology and juvenile hippocampal neurogenesis might both contribute to the observed aberrant behaviour. Furthermore, our results challenge the generally assumed view of a higher radiosensitivity in dividing cells. Overall, this study offers new insights into irradiation-dependent effects in the embryonic brain, of relevance for the neurodevelopmental and radiobiological field.

Electronic supplementary material

The online version of this article (doi:10.1186/1866-1955-7-3) contains supplementary material, which is available to authorized users.     

Reed‐sternberg cells in breast FNA of a patient with left breast mass

Hodgkin's lymphoma is a potentially curable malignancy of the lymphatic system characterized by a variable number of scattered and large mononucleated and multinucleated tumor cells, the Hodgkin and Reed‐Sternberg cells residing in an abundant heterogeneous admixture of non‐neoplastic inflammatory cells. It represents approximately 30% of all lymphomas according to the World Health Organization (WHO). Patients with Hodgkin's lymphoma typically present with painless peripheral adenopathy, fever, night sweats, and weight loss. We report a rare case of Hodgkin's lymphoma presented as a breast mass in a 23‐year‐old woman diagnosed on fine needle aspiration (FNA). At presentation, she had no B symptoms, or palpable lymphadenopathy. Diagn. Cytopathol. 2010;38:663–668. © 2010 Wiley‐Liss, Inc.     

Immortalization and characterization of human myometrial cells from term-pregnant patients using a telomerase expression vector

An examination of cellular processes involved in myometrial function has been greatly assisted by the use of human myometrial cells in primary culture. However, these cells can be used only for several passages before they senesce, and responses to various agents change with time in culture. The use of transformed cells is limited, as they can be polynucleated and can lose or gain chromosomes. We have developed three telomerase-immortalized cell lines from term-pregnant human myometrium to eliminate variability between passage numbers and allow genetic manipulations of myometrial cells to fully characterize signal pathways. These cells have a normal karyotype and were verified to be uterine smooth muscle by immunocytochemical staining for smooth muscle cell-specific alpha-actin and high affinity oxytocin antagonist binding sites. The three cell lines and the cells in primary culture from which they were derived were examined by cDNA microarray analysis. Of >10 000 expressed genes, there were consistent changes in the expression of approximately 1% in the three immortalized cell lines. We were unable to detect any significant differences between primary and immortalized cells in signal pathways such as epidermal growth factor-stimulated epidermal growth factor receptor phosphorylation, insulin-stimulated Akt phosphorylation, oxytocin and lysophosphatidic acid-stimulated extracellular signal-regulated kinase 1 and 2 phosphorylation, myosin light chain phosphorylation, and interleukin-1 induction of IkappaBalpha degradation. The immortalized cells should be useful for a range of studies, including high throughput analyses of the effects of environmental agents on the human myometrium.     

Pyridinium cationic lipids in gene delivery: a structure-activity correlation study

Three series of pyridinium cationic lipids useful as nonviral gene delivery agents were prepared by reaction of pyrylium salts with aminodiols, followed by acylation with fatty acyl chlorides. On the basis of this set of compounds, we undertook a comprehensive structure-activity relationship study at the level of the linker, hydrophobic anchor, and counterion in order to identify the structural elements that generate the highest transfection efficiency for this new type of cationic lipid. The results revealed that when formulated with cholesterol at a 1:1 molar ratio, the 1-(1,3-dimyristoyloxyprop-2-yl)-2,4,6-trimethylpyridinium, under the form of hexafluorophosphate (5AMyr) or chloride (5DMyr), was able to transfect NCI-H23 lung carcinoma with efficiencies surpassing classic DOTAP-based formulations and with lower cytotoxicity. Subsequent tests on other malignancies yielded similarly promising results.     

Carbonic anhydrase inhibitors: water-soluble 4-sulfamoylphenylthioureas as topical intraocular pressure-lowering agents with long-lasting effects

A series of sulfonamides has been obtained by reaction of 4-isothiocyanatobenzenesulfonamide with amines, amino acids, and oligopeptides. The new thiourea derivatives showed strong affinities toward isozymes I, II, and IV of carbonic anhydrase (CA, EC 4.2.1.1). In vitro inhibitory power was good (in the low-nanomolar range) for the derivatives of beta-phenylserine and alpha-phenylglycine, for those incorporating hydroxy and mercapto amino acids (Ser, Thr, Cys, Met), hydrophobic amino acids (Val, Leu, Ile), aromatic amino acids (Phe, His, Trp, Tyr, DOPA), and dicarboxylic amino acids as well as di/tri/tetrapeptides among others. Such CA inhibitors displayed very good water solubility (in the range of 2-3%) mainly as sodium (carboxylate) salts, with pH values of the obtained solutions being 6.5-7.0. Some of these preparations (such as the derivatives of Ser, beta-Ph-Ser, Leu, Asn, etc.) strongly lowered intraocular pressure (IOP) when applied topically, directly into the normotensive/glaucomatous rabbit eye, as 2% water solutions. It is interesting to note that not all the powerful CA inhibitors designed in the present study showed topical IOP-lowering effects (such as, for instance, the Cys and Lys derivatives, devoid of such properties) whereas the Pro, Arg, and oligopeptidyl thiourea derivatives showed reduced efficacy when administered topically. This may be due to the very hydrophilic nature of some of these compounds, whereas inhibitors with balanced hydro- and liposolubility also showed optimal in vivo effects. The interesting pharmacological properties of this new type of CA inhibitors, correlated with the neutral pH of their solutions used in ophthalmologic applications, make them attractive candidates for developing novel antiglaucoma drugs devoid of major ocular side effects.     

Antiestrogen action of progesterone in the breast

This review analyzes recent data from international literature concerning the antiestrogen action of progesterone, progestins and the antiprogesterone RU 486 at the level of mammary cells in culture from either breast cancer lines or normal breast obtained from reduction mammoplasties. Most data indicate that progesterone, progestins and even RU 486 have a strong antiestrogen effect on breast cell appreciated by the decrease of estradiol receptor content, the decrease of cell multiplication and the stimulation of 17 beta-hydroxysteroid activity which may be considered as a marker of breast cell differentiation dependent of progesterone receptor.     

Treatment of diabetic foot lesions in hospital: results of 2 successive five-year periods, 1989-1993 and 1994-1998

OBJECTIVES: To assess the impact of an educational training program we initiated in 1994 for GPs about diabetic foot ulcer (DFU) management, we compared the rate and level of lower limb amputation (LLA) in diabetic patients performed in our unit between two consecutive five-year periods, 1989-1993 and 1994-1998. PATIENTS AND METHODS: During the first period, 132 patients with 163 lesions (9.2% of the total admissions for diabetes) were compared with 176 with 183 lesions (10.5%) during the second period. Patients' mean age was the same in both periods: 59.6 +/- 11.7 in 1989-1993 and 58.3 +/- 13.1 in 1994-1998 [Not statistically significant, NS]. RESULTS: Patients age, sex ratio, type of diabetes and severity of the lesion (as assessed according to Wagner classification) were essentially the same during the two periods. Most of the foot lesions ( approximately 90%) were purely neuropathic or neuro-ischaemic, with no change in repartition between the two periods. Primary healing was 59.1% in the 1st period and 56.8% in the second. No change in minor and major amputation rate was observed between the 1st period (14.4 and 15.9%, respectively) and the second (11.4 and 16.5%, respectively). The in-hospital mortality rate was unchanged (9.1 vs 8.5%, NS), while the percentage of patients who left hospital against medical advice and dropped out of follow up increased from 1.5 to 6.8% (p<0.04). Mean length of hospitalisation was identical, about 43 days. CONCLUSIONS: In spite of implementing educational program for GPs, no improvement in the DFU management was noted as emphasised by absence of any significant change in amputation rate before (1st period) and after initiating the program (2nd period). These disappointing results can be explained by several factors: weakness of our educational program, lack of motivation from GPs, absence of a structured multidisciplinary prevention approach. The main problem, common to developing countries, remains the insufficiency of financial resources. Moreover, civil disturbances can make the problem more difficult to manage, as in Algeria since 1991.     

Management of diabetic foot lesions in hospital: costs and benefits

OBJECTIVE: The aim of this study was to evaluate the direct and indirect costs associated with diabetic-related foot lesions in patients hospitalized in a department of Endocrinology and Diabetology (36 beds). MATERIAL AND METHODS: Direct costs included costs associated with hospital stay, laboratory testing, medical and surgical treatment. Lesions were classified in 3 groups (I, II, III) according to their importance (Wagner classification). RESULTS: Among 1,779 admissions for diabetes, 163 (i.e., 9.16%) were related to a foot lesion. The stay in hospital for these lesions reached 7,247 days over a 5-year period, with an average stay duration of 45 days per lesion. Mean length of hospital stay varied according to the importance of the lesion: 26.87 days, 48.25 days, 57.12 days for group I, II and III, respectively. The total cost amounted to 914,534.39 US dollars and the mean cost 5,610.64 US dollars. Mean cost was 3,326.76, 5,712.24, 7,399.74 US dollars for group I, II and III, respectively. Nearly 80% of the financial costs were due to hospital stay. Primary healing occurred in 59.09% of the patients (n=78); 17.4% (n=23) of the patients required major amputation, 14.4% (n=19) minor amputation. Death rate reached 9.1% (n=12). CONCLUSION: An increase in length of stay and costs with importance of the lesion was identified. The strategy of care of the diabetic lesions should be based upon the prevention of ulcer formation: it seems actually the best mean (the least expensive) in a developing country where financial resources are very limited. This prevention should be made through regular patient education, appropriately fitted shoes, and regular careful examination by a General Practitioner or a Diabetologist.