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.

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.

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.

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.

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.

Intra-operative control of carotid thromboendoarterectomy by Doppler spectrum analysis.

The authors report their experience with intraoperative Doppler spectrum analysis of carotid flow after thromboendoarterectomy. The method seems to be useful in the early localisation of technical defects potentially responsible for postoperative stroke. In 22 patients operated on consecutively, three major abnormalities were detected, one of the internal and two of the external carotid. This enabled immediate reexploration of the involved artery with restoration of normal flow. This kind of examination is also safe, quick and highly accurate. The authors propose it as a substitute to intraoperative arteriography which is routinely performed by some surgeons after carotid thromboendoarterectomy.

Surgical treatment of lesions obstructing the external carotid artery.

Atherosclerotic lesions obstructing the external carotid artery are generally disregarded in the evaluation of patients with symptoms of cerebral ischemia; nevertheless, in the presence of occlusion of the ipsilateral or of both the internal carotid arteries, external carotid artery endarterectomy may be indicated, in order to increase the flow to the brain through collaterals. A lesion of the external carotid artery may be the source of retinal emboli; patients may benefit from surgical treatment of the lesion. The Authors of the present paper operated on 6 such patients, from a total of 230 carotid bifurcation endarterectomies performed in the period between January 1982 and March 1988. Morbidity and mortality were nil and 5 of the 6 patients are free of symptoms after a mean follow-up period of 23 months. One patient died 2 months after surgery due to a myocardial infarction. On the basis of this experience, the Authors discuss indications, surgical techniques and results of the surgical treatment of lesions obstructing the external carotid artery.

Direct and indirect evaluation of lesions obstructing the carotid bifurcation. A comparison of Doppler spectrum analysis with angiography.

The diagnostic accuracy of real-time continuous wave (c.w.) Doppler spectrum analysis and of indirect periorbital Doppler examination for detecting carotid bifurcation disease was evaluated. The results of non-invasive studies were compared with contrast arteriograms of patients studied for symptomatic cerebrovascular disease (91%) or for asymptomatic bruits (9%). Periorbital examination was insensitive to less than 75% carotid stenoses and sensitivity to severe stenoses or occlusions was respectively 56% and 85% (mean 73%). Mean sensitivity of real-time C.W. Doppler spectrum was 93% and sensitivity to stenoses of less than 45% diameter reduction was equal to 76%, while specificity in identifying normal carotid arteries was 89% for an accuracy of the method of 91%. Positive and negative predicting values were respectively 89% and 93%. Direct Doppler interrogation of the carotid arteries with real-time C.W. Doppler spectrum analysis was able to distinguish operable stenoses from inoperable occlusions in 87% of the cases.

Factors affecting prognosis in acute intestinal ischemia.

The anamnestic, clinical, laboratory, radiological and intraoperative data on 34 consecutive patients affected by acute intestinal ischemia or infarction, caused by superior mesenteric obstructive and nonocclusive pathology were collected and assessed. The aim of this study is the identification of the factors influencing the prognosis which in this disease is still really displeasing, with a mortality of over 90% in many surveys, and 73.5% in this report. The mean age of the 34 patients was 73. Cardiac ischemic disease and or arrhythmias were present in 83.8% of the patients. The most significant prognostic factors were those related to the evolutive stages of the intestinal ischemia. Among the anamnestic ones, the interval between the onset of the symptoms and diagnosis (mortality of 50% if less than or equal to 24 hrs., 86.4% if greater than 24 hrs.). Among the clinical factors, the presence of peritoneal signs was followed by a mortality of 82.3%, in contrast with the 33.3% when the same signs were absent. Also significant was the presence of shock (100% mortality), in contrast with 50% in patients presenting systemic systolic pressure greater than 100 mmHg. Extensive intestinal infarction caused a 100% mortality rate, while early revascularization allowed the survival of 81.8% of the patients treated in the absence of infarction or when irreversible ischemic damage was limited to less than 1 meter of bowel.

Value of Doppler multi-level segmental pressure index in the diagnosis and hemodynamic characterization of totally occlusive aorto-iliac-femoro-popliteal lesions.

Four-level lower limb Doppler S.P.I. (upper thigh; above knee; below knee; above ankle) were evaluated in 275 limbs, 110 of which showed totally occlusive lesions at one or more levels of the aorto-iliac-femoro-popliteal axis on angiographic examination, 65 showed stenosis less than 50% (sclerotic controls) and 100 did not undergo arteriographic examination since they apparently had no lesions (healthy controls). Analysis of the results-carried out using the Student's t statistical method-showed a drop in the S.P.I. close to or over 0.30 between two adjacent levels and was indicative of the presence of an occlusion in the intermediate area. This method therefore allowed the presence and the position of an isolated lesion to be detected. In the case of multiple lesions in series, the proximal one is detected with certainty, whereas the more distal ones can be recognized but not their exact position and extension. Multiple lesions in series are more hemodynamically significant than isolated ones, and proximal lesions more than distal ones.

Value and limits of "critical auscultation" of neck bruits.

Within a group of 2,000 patients evaluated, most of them with symptoms of cerebrovascular insufficiency, 441 had a monolateral or bilateral cervical bruit. The 627 sides with an audible bruit were divided into main groups (A) symptomatic (TIA and/or stroke homolateral to the bruit), (B) possibly symptomatic (non-side-related symptoms), (C) asymptomatic (C1, in totally asymptomatic patients; C2, in patients with symptoms dependent on the hemisphere contralateral to the cervical bruit). Each patient was studied by means of clinical (history, blood pressure in both upper limbs, phonoendoscopic auscultation at various levels) and noninvasive instrumental examinations (CW Doppler spectrum analysis). An apparently primitive cervical bruit corresponded to a lesion of the carotid bifurcation in 61% of the cases (positive predictive value) whereas a normal bifurcation was detected in 70% of the cases in which the cervical bruit was considered as secondary (negative predictive value); the diagnostic accuracy of the "critical auscultation" has a value therefore of 63%, with a sensitivity of 84% and a specificity of 40%. The results obtained in the different groups of patients (symptomatic or asymptomatic) were not significantly different (chi-square). Even though maintaining the value of a cervical bruit as a sign of carotid stenosis or occlusion and consequently confirming the importance of neck auscultation, the authors conclude that the critical auscultation as commonly performed is not capable of excluding the presence of a carotid lesion with sufficient reliability, even in totally asymptomatic patients.

[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.

[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.

[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.

[Peroperative morbidity and mortality in thromboendarterectomy of the carotid bifurcation in patients with a previous stabilized stroke. Our results and review of the literature]. / Morbilità e mortalità perioperatoria della tromboendoarterectomia della biforcazione carotidea in pazienti con pregresso ictus stabilizzato. Nostri risultati e revisione della letteratura.

Carotid endarterectomy (CE), when performed in patients with previous stable stroke followed by complete or almost complete recovery, seems to be affected by a higher peroperative risk. From January 1982 to March 1988, we performed 230 CE in 207 patients, 188 (81.8%, Group 1) in patients with TIA or an asymptomatic plaque and 42 (18.2%, Group 2) in patients with previous strokes. The need for a temporary indwelling shunt has been evaluated with the measurement of carotid back pressure and, in the last 100 CEE, with the monitoring of somatosensory evoked responses (the shunt has however been used routinely anyway in the very first part of our experience). The incidence of carotid back-pressure values and of positive somatosensory evoked responses were similar in the two groups of C.E., even if the differences in the prealable evaluation were not statistically significant. The shunt has been nevertheless used more frequently in Group 2 (40.5 vs 28.2%). Statistical analysis has been performed with the chi 2 method. The incidence of permanent and transient neurologic deficits and of the peroperative mortality due to neurological and non-neurological causes was, respectively, 0.5, 2.6, 1.6, 0% (Group 1) and 2.4, 7.3, 2.4, 2.4% (Group 2) (non-significant). If we exclude the first 50 operations (in which technical and/or anaesthesiological problems may have influenced the neurological outcome of the patients operated upon), the previous values become, respectively, 0,07*, 0,7, 0% (Group 1) and 0, 5,5*, 0, 2,7% (Group 2) (*p less than 0,01, the only significant difference).(ABSTRACT TRUNCATED AT 250 WORDS)

[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.

[Splenic autografts in omental and subcutaneous pouches. An experimental study]. / Autoinnesti splenici in tasche omentali e sottocutanee. Studio sperimentale.

An accurate morphological study has been done on splenic grafts in rats after 7-15-30 days from their implant in omental or subcutaneous pouches. Observation after 7 days confirmed the necrosis of all the central portion of the implants. Anyway, marginal parts of the graft survived to ischaemia and showed to be supplied by vessels, coming from the contiguous tissues. In these parts the rigenerative process had begun from the structures of red residual pulp, by reticular cells proliferating so to rigenerate the capsula limiting the place of the central necrotic area. After 15 days the neocapsula was completed and from it neoformed trabecolae departed accompanied with chords, sinus capillary, venular and arteriolar vessels which reformed the structure of red pulp both in peripheral and central area, now undistinguishable. After 30 days lymphocytes aggregating around the neoformed vessels promoted a rudimental reconstruction of the white pulp too. In conclusion, splenic implants are able to get over the ischaemic phase and after 30 days the red pulp is morphologically reconstructed and probably functioning, while the white pulp is still primordial.

[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)

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.