Passage of uranium through human cerebral microvascular endothelial cells: influence of time exposure in mono- and co-culture in vitro models.

PURPOSE: Depleted uranium (DU) has several civilian and military applications. The effects of this emerging environmental pollutant on human health raise some concerns. Previous experimental studies have shown that uranium (U) exposure can disturb the central nervous system. A small quantity of U reaches the brain via the blood, but the effects on the blood-brain barrier (BBB) remain unclear. MATERIALS AND METHODS: In the present work, two cell culture models were exposed to DU for different times to study its cytotoxicity, paracellular permeability and extracellular concentration of U. The well-known immortalized human cerebral microvascular endothelial cells, hCMEC/D3, were cultured on the filter in the first model. In the second model, human primary cells of pericytes were cultured under the filter to understand the influence of cell environment after U exposure. RESULTS: The results show that U is not cytotoxic to hCMEC/D3 cells or pericytes until 500 µM (1.6 Bq.L-1). In addition, acute or chronic low-dose exposure of U did not disturb permeability and was conserved in both cell culture models. However, U is able to reach the brain compartment. During the first hours of exposure, the passage of U to the abluminal compartment was significantly reduced in the presence of pericytes. Electronic microscopy studies evidenced the formation of needlelike structures, like urchin-shaped precipitates, from 1 h of exposure. Analytical microscopy confirmed the U composition of these precipitates. Interestingly, precipitated U was detected only in endothelial cells and not in pericytes. U was localized in multilamellar or multivesicular bodies along the endo-lysosomal pathway, suggesting the involvement of these traffic vesicles in U sequestration and/or elimination. CONCLUSIONS: We show for the first time the in vitro passage of U across a human cerebral microvascular endothelial cells, and the intracellular localization of U precipitates without any cytotoxicity or modification of paracellular permeability. The difference between the results obtained with monolayers and co-culture models with pericytes illustrates the need to use complex in vitro models in order to mimic the neurovascular unit. Further in vivo studies should be performed to better understand the passage of U across the blood-brain barrier potentially involved in behavioral consequences.

External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio.

In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

Uranium-induced sensory alterations in the zebrafish Danio rerio.

The effect of chronic exposure to uranium ions (UO(2)(2+)) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 µg l(-1) for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes>olfactory bulbs>skin>muscles>brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

Developmental energetics of zebrafish, Danio rerio.

Using zebrafish (Danio rerio) as a case study, we show that the maturity concept of Dynamic Energy Budget (DEB) theory is a useful metric for developmental state. Maturity does not depend on food or temperature contrary to age and to some extent length. We compile the maturity levels for each developmental milestone recorded in staging atlases. The analysis of feeding, growth, reproduction and aging patterns throughout the embryo, juvenile and adult life stages are well-captured by a simple extension of the standard DEB model and reveals that embryo development is slow relative to adults. A threefold acceleration of development occurs during the larval period. Moreover we demonstrate that growth and reproduction depend on food in predictable ways and their simultaneous observation is necessary to estimate parameters. We used data on diverse aspects of the energy budget simultaneously for parameter estimation using the covariation method. The lowest mean food intake level to initiate reproduction was found to be as high as 0.6 times the maximum level. The digestion efficiency for Tetramin™ was around 0.5, growth efficiency was just 0.7 and the value for the allocation fraction to soma (0.44) was close to the one that maximizes ultimate reproduction.

Effects of chronic internal alpha irradiation on physiology, growth and reproductive success of Daphnia magna.

Daphnids were chronically exposed to waterborne Am-241, an alpha-emitting radionuclide, ranging in concentration from 0.4 to 40 Bq ml(-1). Am-241 amounts were monitored in the medium, daphnid tissues and cuticles. Corresponding average dose rates of 0.02, 0.11 and 0.99 mGy h(-1) were calculated for whole organisms with internal alpha-radiation contributing 99% of total dose rates. Effects of internal alpha irradiation on respiration and ingestion rates, adult, egg and neonate individual dry masses, fecundity and larval resistance to starvation were examined in 23-day experiments. Daphnids showed increased respiratory demand after 23 days at the highest dose rate, suggesting increased metabolic cost of maintenance due to coping with alpha radiological stress. Although no effect was detected on ingestion rates between contaminated and control daphnids, exposure to dose rates of 0.11 mGy h(-1) or higher, resulted in a significant 15% reduction in body mass. Fecundity remained unchanged over the 23-day period, but individual masses of eggs and neonates were significantly smaller compared to the control. This suggested that increased metabolic expenditure in chronically alpha-radiated daphnids came at the expense of their energy investment per offspring. As a consequence, neonates showed significantly reduced resistance to starvation at every dose rate compared to the control. Our observations are discussed in comparison with literature results reported for cadmium, a chemical toxicant which affects feeding activity and strongly reduces individual energy uptake.

Phosphate deficiency promotes modification of iron distribution in Arabidopsis plants.

Phosphate (Pi) is an essential element for plant development and metabolism. Due to its low availability and mobility in soils, it is often a limiting nutrient for their growth. This phenomenon is reinforced by the formation of insoluble complexes in the environment with many cations, affecting the solubility of both phosphate and associated ions. This interaction is investigated here for iron, a strong phosphate chelator. Depleting the medium in phosphate clearly resulted in an increase of iron content in Arabidopsis. These modifications triggered molecular responses linked with iron status (transport, homeostasis and accumulation). Interestingly, physiological modifications affecting iron storage were also observed. The accumulation of phosphate/iron complexes in the vacuoles of plants grown in Pi-rich medium disappeared in Pi-depleted medium in favor of accumulation of iron inside the chloroplasts, likely associated with ferritin.

Dramatic development of severe SLE in a patient with an incomplete disease.

This case report describes the previously-unreported clinical course of a patient with a so-called incomplete systemic lupus erythematosus (SLE), i.e. symptoms related to one organ system only, together with the presence of ANA. He had an indolent course initially and developed, 6 months after the first symptoms, a severe disease with rapid appearance of major and unusual manifestations. The possibility of fast progression and a grave course of an incomplete SLE should be kept in mind. This report is meant to heighten awareness of such an atypical presentation so that prompt and aggressive immunosuppressive therapy may be instituted.

[Simultaneous multiregional embolization from a cardiac myxoma. Case report]. / Embolizzazione sincrona pluridistrettuale da mixoma cardiaco. Presentazione di un caso clinico.

Atrial myxoma is the most frequent cardiac tumor. Distal embolization occurs in about one third of the patients with this nosological entity; a simultaneous embolization to three different arterial districts, however, is a rare event. Of particular interest is also, in our opinion, the evolution of the clinical picture and the surgical treatment performed.

[Infection of aorto-bifemoral vascular prosthesis complicated by multiple visceral fistulas. A case report]. / Infezione di protesi vascolare aorto-bifemorale complicata da fistolizzazioni viscerali multiple. Presentazione di un caso.

The authors present the case of a late aorto-bifemoral graft infection: the pecularity of the case lies on the contemporary existence of multiple visceral phistulas beetween perigraft collection, the duodenum, the large bowel and the bladder. The phatogenetic mechanism of the clinical event is discussed.

[Gastric leiomyoblastoma: report of our case load]. / Il leiomioblastoma gastrico: presentazione della nostra casistica.

Leiomyoblastoma of the stomach is a rare nosological entity (0.3% of all gastric tumors). During the last 13 years, the authors observed 7 of such tumors. In this paper, our cases are presented: these are discussed (together with a revision of the literature), particularly focusing on anatomo-pathological, diagnostic and therapeutic problems.

[Pancreatic and duodenal injuries. Considerations on 40 observed cases]. / I traumi del pancreas e del duodeno. Considerazioni su 40 casi osservati.

Traumatic lesions of the pancreas and duodenum are uncommon. The anatomic situation of the viscera makes early diagnosis of such lesions difficult to be achieved; this fact, together with the high incidence of associated lesions, justify the high morbidity and mortality of duodeno-pancreatic traumas. In the present paper we report the two-decades experience (40 traumatic lesions of the pancreas and/or the duodenum) of the Department of Emergency Surgery, University of Milan. The overall mortality (32.5%), even if correlated with the importance of the duodeno-pancreatic lesions, was strictly dependent to the presence of associated injuries which lead to most of the morbidity and mortality.

Monitoring of somatosensory evoked potentials during carotid endarterectomy: relationship with different haemodynamic parameters and clinical outcome.

The authors studied the changes of Somatosensory Evoked Potentials (SEPs) performed in 241 anaesthetised patients during 264 carotid endarterectomies (CEs). SEP responses were considered significantly modified when the central conduction time was greater than 1 ms and/or when the amplitude of the complex N20-P25 decreased by at least 50%. Both CCT and N20-P25 have been correlated with different parameters, including the presence or absence of preoperative neurological deficits, the type of general anaesthesia, the status of the contralateral and the ipsilateral carotid artery, stump pressure, the use of an intraluminal shunt and the perioperative results. After carotid cross-clamping SEP responses were within the normal range in 236 CEs (89%), and abnormal in 28 (11%). A shunt was inserted 23 times in 264 (9%) cases. None of the patients operated on in this series experienced a permanent neurological deficit; there were three (1.1%) transient deficits (two Rinds and one TIA) and two deaths from non-neurological causes. Only one of the transient deficits was present when the patient woke from the anaesthetic and this event was predicted by significant modification of the SEP which did not reverse after removal of the clamps (a shunt was not used). None of the patients in our series who did not present significant modifications of SEPs during the operation had any postoperative neurological deficit. The authors conclude that SEP recording is a highly reliable and objective method for continuous monitoring of brain function during CE.

[Scintigraphy using 99m-TC HM-PAO labeled autologous granulocytes in the diagnosis of Whipple's disease]. / La scintigrafia con granulociti autologhi marcati con 99mTc-HM-PAO nella diagnosi della malattia di Whipple.

Whipple's disease is a systemic disease, mainly localized in the small intestine, that even today shows some difficulties about its etiopathogenesis and diagnosis. The surveys usually used in the diagnosis, among which the biopsy is an indispensable test, have some limits particularly in follow-up. The 99mTc-HM-PAO labelled granulocytes scintigraphy may be a useful alternative method in the evaluation of location and extension of the Whipple's disease. Furthermore, as it is not an invasive method, 99mTc granulocyte scintigraphy may be an important means in establishing the term of the therapy mainly when other methods are not able to exactly confirm the remission of the disease.

[Carotid thromboendarterectomy in old age]. / La TEA carotidea nell'età avanzata.

Data obtained in 323 carotid bifurcation endarterectomies and in 77 patients affected by extracranial internal carotid artery stenosis not operated, have been analyzed in relation to patients' age: Group 1 less than or equal to 69 years old (268 cases operated on and 59 not operated), and Group 2 greater than or equal to 70 years old (55 cases operated on and 18 not operated). Among the operated patients, the most important anaesthetic risk factors, the type of neurological symptoms, and the diameter of the lesion did not turn out significantly different between the two age groups, except for the patients operated on because of stenoses less than or equal to 50% of carotid lumen reduction (42 cases in Group 1 and 1 case in Group 2, p less than 0.001). The overall operative mortality rate was 1.8% (6/323 carotid endarterectomies): 1.5% in Group 1 (4/268 cases, 2 due to stroke and 2 to heart disease), and 3.6% in Group 2 (2/55 cases, both due to stroke) (N.S.). The overall neurological morbidity was 0.6%, owing to 2 strokes both found in Group 2 (3.6% of patients greater than or equal to 70 years). Therefore, the overall incidence of fatal and non fatal stroke was 1.8% (6/323 carotid endarterectomies): 0.7% (2 cases) in Group 1, and 7.3% (4 cases) in Group 2 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Immediate detection of postreconstructive ischaemia by intra-operative Doppler ankle pressure index monitoring during aortic reconstructions.

From March 1980 to February 1988, 368 aorto-iliac or aorto-femoral bilateral reconstructions were performed for aneurysmal or occlusive disease. In order to demonstrate early postreconstructive ischaemic complications, the intra-operative Doppler Ankle Pressure Index (API) was measured immediately before reconstruction (PRE), just after declamping (DEC) and 5, 15, 30 and 45 min thereafter. Each limb of the reconstruction (736) was considered individually and subdivided as follows: Group (A) 705 immediately successful (96% of limbs and 92% of patients); Group (B) 22 (3% of limbs and 5% of patients) in which, on the grounds of API data, an ischaemic complication was regarded as imminent and treated by graft revision or a peripheral thromboembolectomy (intra-operative corrections); Group (C) 9 (1% of limbs and 2% of patients) in which the diagnosis of ischaemic complications was made postoperatively when the patients underwent successful reoperation. All 736 reconstructions were patent and functional at discharge of the patient. By a retrospective analysis the intra-operative APIs were studied and the features (single or associated) suggesting an ischaemic complication examined. These were: (1) no flow at the time of declamping or its disappearance during the operation (10 cases, 1.25% of limbs) all detected and successfully corrected intra-operatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of cervical bruit for the detection of obstructive lesions of the internal carotid artery. Data from 2000 patients.

Between January 1982 and June 1985, 2000 patients with either symptoms of cerebrovascular insufficiency (1873) or asymptomatic cervical bruits (127) were studied at the Surgical Department of the University of Brescia (Italy). Of these, 441 presented a mono- or bilateral cervical bruit. The value of the bruit as indicator of an obstructive pathology of the extracranial carotid artery was evaluated in comparison with the findings of Doppler spectrum analysis. A stenosis or occlusion of the internal carotid artery was present in 51% of the patients with a bruit (homolateral to the bruit in 91% of the cases) and in 9% of those without a bruit. Stenoses of a medium-high degree were those more often associated with the bruit. Both in patients with bruit and in those without bruit the age and the severity of the presenting symptoms significantly influenced the rate of association with lesions of the internal carotid artery was present in 51% of the patients with a bruit (homolateral to the bruit in 91% of the cases) and in 9% of those without a bruit. Stenoses of a medium-high degree were those more often associated with the bruit. Both in patients with bruit and in those without bruit the age and the severity of the presenting symptoms significantly influenced the rate of association with lesions of the internal carotid artery.