Applications of iodine-125 plaque radiotherapy for residual or recurrent retinoblastoma.

OBJECTIVE: To determine the role of iodine-125 plaque radiotherapy (IPR) as a secondary treatment for localized (solitary or multiple) residual (partially regressed) or recurrent (regrowth after ≥6 months stability) retinoblastoma in the era of systemic and/or regional chemotherapy. DESIGN: A single-institute retrospective, noncomparative, interventional case series managed between July 2014 and June 2019. PARTICIPANTS: Thirteen consecutive eyes of 12 patients with 14 residual or recurrent retinoblastoma tumors treated with IPR. Patients who had to follow up <1 year post-IPR were excluded except for those who had enucleation. METHODS: Data collected included pre-IPR treatments, tumor characteristics at IPR, and post-IPR anatomical outcome (local tumor control and globe salvage) and functional outcome (radiation complications). RESULTS: Local tumor control was achievable in 12 of 14 tumors. Local recurrences were observed in 2 of 5 tumors that exhibited fish-flesh regression after IPR (p = 0.04). Globe salvage was possible in 11 eyes (12 tumors). Only 2 eyes were legally blind and the remaining 9 eyes had vision >20/125. Radiation-induced complications included radiation retinopathy (4/11), radiation papillopathy (1/11), diffuse vitreous hemorrhage (4/11). Eyes with fish-flesh-regressed tumours tended to show more complications, but were statistically insignificant (p = 0.09, Fisher exact test). There was no association of time to IPR (early <6 months vs late >6 months) with occurrence of tumor recurrence or complications (p > 0.05). CONCLUSION: IPR offers satisfactory local tumor control and globe salvage in localized recurrent/residual retinoblastoma. Fish-flesh tumor regression after IPR should be closely monitored for further recurrences.

Molecular analysis confirms retinoblastoma diagnosis in a histologically undifferentiated retinal tumor in an adult.

Retinoblastoma is the most common pediatric intraocular cancer. Rarely, it may develop in adults, with different clinical and imaging characteristics that make the diagnosis a challenge. We present a case of a white retinal tumor in a 42-year-old woman that progressed slowly over 3 years and on enucleation an undifferentiated tumor was found without a conclusive diagnosis. Molecular analysis identified RB1 pathogenic variant that confirmed retinoblastoma diagnosis in this discordant clinicopathologic presentation of the tumor.

Melatonin promotes Bax sequestration to mitochondria reducing cell susceptibility to apoptosis via the lipoxygenase metabolite 5-hydroxyeicosatetraenoic acid.

Extra-neurological functions of melatonin include control of the immune system and modulation of apoptosis. We previously showed that melatonin inhibits the intrinsic apoptotic pathway in leukocytes via stimulation of high affinity MT1/MT2 receptors, thereby promoting re-localization of the anti-apoptotic Bcl-2 protein to mitochondria. Here we show that Bcl-2 sequesters pro-apoptotic Bax into mitochondria in an inactive form after melatonin treatment, thus reducing cell propensity to apoptosis. Bax translocation and the anti-apoptotic effect of melatonin are strictly dependent on the presence of Bcl-2, and on the 5-lipoxygenase (5-LOX) metabolite 5-hydroxyeicosatetraenoic acid (5-HETE), which we have previously shown to be produced as a consequence of melatonin binding to its low affinity target calmodulin. Therefore, the anti-apoptotic effect of melatonin requires the simultaneous, independent interaction with high (MT1/MT2) and low (calmodulin) affinity targets, eliciting two independent signal transduction pathways converging into Bax sequestration and inactivation. MT1/MT2 vs. lipoxygenase pathways are activated by 10(-9) vs. 10(-5)M melatonin, respectively; the anti-apoptotic effect of melatonin is achieved at 10(-5)M, but drops to 10(-9)M upon addition of exogenous 5-HETE, revealing that lipoxygenase activation is the rate-limiting pathway. Therefore, in areas of inflammation with increased 5-HETE levels, physiological nanomolar concentrations of melatonin may suffice to maintain leukocyte viability.

Ultrasonography of salivary glands in primary Sjögren's syndrome: a comparison with contrast sialography and scintigraphy.

OBJECTIVE: To compare ultrasonography (US) of salivary glands with contrast sialography and scintigraphy, in order to evaluate the diagnostic value of this method in primary SS (pSS). METHODS: The diagnostic value of parotid gland US was studied in 77 patients with pSS (male/female ratio 3/74; mean age 54 yrs) and in 79 with sicca symptoms but without SS. The two groups were matched for sex and age. Imaging findings of US were graded using an ultrasonographic score ranging from 0 to 16, which was obtained by the sum of the scores for each parotid and submandibular gland. The sialographic and scintigraphic patterns were classified in four different stages. The area under receiver operating characteristic curve (AUC-ROC) was employed to evaluate the screening method's performance. RESULTS: Of the 77 patients with pSS, 66 had abnormal US findings. Mean US score in pSS patients was 9.0 (range from 3 to 16). Subjects without confirmed pSS had the mean US score 3.9 (range from 0 to 9) (P < 0.0001). Results of sialography showed that 59 pSS patients had abnormal findings at Stage 1 (n = 4), Stage 2 (n = 8), Stage 3 (n = 33) or Stage 4 (n = 14), and 58 patients had abnormal scintigraphic findings at Stage 1 (n = 11), Stage 2 (n = 18), Stage 3 (n = 25) or Stage 4 (n = 4). Through ROC curves US arose as the best performer (AUC = 0.863 +/- 0.030), followed by sialography (AUC = 0.804 +/- 0.035) and by salivary gland scintigraphy (AUC = 0.783 +/- 0.037). The difference between AUC-ROC curve of salivary gland US and scintigraphy was significant (P = 0.034). Setting the cut-off score >6 US resulted in the best ratio of sensitivity (75.3%) to specificity (83.5%), with a likelihood ratio of 4.58. If a threshold >8.0 was applied the test gained specificity, at the cost of a serious loss of sensitivity (sensitivity 54.5%, specificity 97.5%, likelihood ratio 21.5). CONCLUSIONS: Salivary gland US is a useful method in visualizing glandular structural changes in patients suspected of having pSS and it may represent a good option as a first-line imaging tool in the diagnostics of the disease.

The spectrum of iris angiography abnormalities in pseudoexfoliation syndrome.

PURPOSE: To analyse the spectrum of angiographic features in patients monolaterally or bilaterally affected by pseudoexfoliation syndrome (PES), with and without glaucoma, and to evaluate the sensibility and specificity of these features in the diagnosis of glaucoma. METHODS: Sixty-eight patients affected by PES and 20 healthy subjects underwent iris fluorescein angiography (IFA) and iris indocyanine green angiography (IICGA). Angiographic features analysed were hypoperfusion, microneovascularizations, and anastomotic vessels. RESULTS: There was no statistically significant difference among unaffected, unilaterally affected, and bilaterally affected eyes. Patients affected by PES glaucoma showed a statistically significant difference with respect to the other groups for most of the variables. The results of qualitative variables revealed a gradual increase of the vascular involvement in the different groups. Peripupillary tufts, stromal tufts, and radial arterioles showed the best sensibility and specificity values on IFA, whereas radial arterioles and plexuses showed the highest sensibility and specificity values on IICGA. Considering all the parameters, the results were not associated with large effects on the post-test probability of disease. The values of likelihood ratio indicated that none of the examined variables was sufficiently able to discriminate patients affected by PSE glaucoma from the overall group. CONCLUSIONS: Patients clinically affected only monolaterally by PES show microvascular changes, which are similar in both eyes. Glaucoma PES represents a more advanced stage of the disease, with more pronounced alterations, even though no typical microvascular pattern can be identified by iris angiography.

237 ACoA aneurysms clipped or embolized. Outcomes measurement using the De Santis-CESE assessment tool.

AIM: The aim of this retrospective study was to demonstrate the difference in patient outcomes after treatment for bleeding endocranial aneurysms when evaluated with methods based on different assessment criteria. METHODS: The outcome of 237 patients, 141 of which were operated on for anterior communicating artery aneurysm and 96 embolized, was assessed by a new method developed by De Santis. The patients operated on were assessed by the Glasgow Outcome Scale (GOS) and Rank Disability Scale (RDS) and the results of the latter were compared with the new method, the De Santis-CESE (Clinical Emotional Social Evaluation) method, which consists of a clinical evaluation and a numeric scoring system based on seven standard points. Comparison between the three methods showed significantly different outcomes. Patients who underwent surgical operation showed changes in character and behaviour, whereas the others showed cognitive, emotional and sexual habit changes. CONCLUSION: Compared with the GOS and RDS instruments, the CESE method showed significant differences in patient outcome assessment, particularly regarding best outcomes. These differences may be due to the greater sensitivity of the CESE method over the other two scales. Furthermore, surgical patients seemed to achieve a better outcome than endovascular patients. The authors intend to conduct a prospective study to test the results obtained in this retrospective study.

HIV protease inhibitor therapy reverses neutrophil apoptosis in AIDS patients by direct calpain inhibition.

The reduction of neutrophils apoptosis is one of the main non-virological effects of protease inhibitor (PI) therapy. We explore here whether this may be due to the cross-inhibition of calpain, an important non-virological target of PI in vitro. We found that the high basal level of neutrophils apoptosis in AIDS patients is strictly related to an increased intracellular calpain activity. Both alterations disappear after PI treatment, with apoptosis and calpain going back to normal levels after 3 months of PI therapy, independently of a proficient antiviral effect. PI drugs exerted a similar antiapoptotic and anticalpain effects on neutrophils in ex vivo experiments: strikingly, the effects were mimicked by commercially available calpain inhibitors. This study shows, for the first time, that apoptosis of neutrophils in AIDS patients is mediated by calpain, and that neutrophil survival in PI treated AIDS patients is a non virological effect due to calpain inhibition.

NMR exposure sensitizes tumor cells to apoptosis.

NMR technology has dramatically contributed to the revolution of image diagnostic. NMR apparatuses use combinations of microwaves over a homogeneous strong (1 Tesla) static magnetic field. We had previously shown that low intensity (0.3-66 mT) static magnetic fields deeply affect apoptosis in a Ca2+ dependent fashion (Fanelli et al., 1999 FASEBJ., 13;95-102). The rationale of the present study is to examine whether exposure to the static magnetic fields of NMR can affect apoptosis induced on reporter tumor cells of haematopoietic origin. The impressive result was the strong increase (1.8-2.5 fold) of damage-induced apoptosis by NMR. This potentiation is due to cytosolic Ca2+ overload consequent to NMR-promoted Ca2+ influx, since it is prevented by intracellular (BAPTA-AM) and extracellular (EGTA) Ca2+ chelation or by inhibition of plasma membrane L-type Ca2+ channels. Three-days follow up of treated cultures shows that NMR decrease long term cell survival, thus increasing the efficiency of cytocidal treatments. Importantly, mononuclear white blood cells are not sensitised to apoptosis by NMR, showing that NMR may increase the differential cytotoxicity of antitumor drugs on tumor vs normal cells. This strong, differential potentiating effect of NMR on tumor cell apoptosis may have important implications, being in fact a possible adjuvant for antitumor therapies.

Magnetic fields protect from apoptosis via redox alteration.

Magnetic fields (MFs) are receiving much attention in basic research due to their emerging ability to alter intracellular signaling. We show here that static MFs with intensity of 6 mT significantly alter the intracellular redox balance of U937 cells. A strong increase of reactive oxygen species (ROS) and a decrease of glutathione (GSH) intracellular levels were found after 2 h of MF exposure and maintained thereafter. We found that also other types of MFs, such as extremely-low-frequency (ELF) MFs affect intracellular GSH starting from a threshold at 0.09 mT. We previously reported that static MFs in the intensity range of 0.3-60 mT reduce apoptosis induced by damaging agents (Fanelli et al., 1998). Here, we show that ELF-MFs are also able to protect U937 from apoptosis. Interestingly, this ability is limited to the ELF intensities able to alter redox equilibrium, indicating a link between MF's antiapoptotic effect and the MF alteration of intracellular redox balance. This suggests that MF-produced redox alterations may be part of the signaling pathway leading to apoptosis antagonism. Thus, we tested whether MFs may still exert an antiapoptotic action in cells where the redox state was artificially altered in both directions, that is, by creating an oxidative (via GSH depletion with BSO) or a reducing (with DTT) cellular environment. In both instances, MFs fail to affect apoptosis. Thus, a correct intracellular redox state is required in order for MFs to exert their antiapoptotic effect.

The cleavage mode of apoptotic nuclear vesiculation is related to plasma membrane blebbing and depends on actin reorganization.

In U937 monocytic cells induced to apoptosis, plasma membrane blebbing of different intensities appears, before the development of nuclear alterations; this latter phenomenon can occur through two major pathways, namely the cleavage and the budding mode (Dini et al., 1996). Strongly blebbing cells develop deep nuclear constrictions leading to nuclear fragmentation according to the cleavage mode, while cells with milder forms of blebbing, or no blebbing at all, undergo nuclear fragmentation along the budding mode. Compounds interfering with different cytoskeletal components affect blebbing, which is completely inhibited by the actin polymerization inhibitors, cytochalasins, while disturbance of tubulin network with taxol limits blebbing to milder forms. At the same time, the cytoskeletal poisons affect the type of nuclear fragmentation, abolishing the cleavage mode, shifting all events into the budding pathway. Adherent cells, which possess a more structured cytoskeleton, do not develop strong blebs and undergo nuclear fragmentation via budding. These observations suggest that the deep cytoskeletal movements that cause the strongest forms of plasma membrane blebbing strangle the nucleus, leading to the constrictions that later evolve into nuclear fragmentation by cleavage. The trigger for the cytoskeletal movements, known to be redox-sensitive, is probably the apoptotic GSH extrusion.

Hyperpolarization of plasma membrane of tumor cells sensitive to antiapoptotic effects of magnetic fields.

Chemical/physical agents able to prevent apoptosis are receiving much attention for their potential health hazard as tumor promoters. Magnetic fields (MFs), which have been shown to increase the occurrence of some tumors, reduce damage-induced apoptosis by a mechanism involving Ca2+ entry into cells. In order to discover the mechanism of such effect of MFs, we investigated the interference of MFs on cell metabolism and analyzed cell parameters that are involved in apoptotic signaling and regulation of Ca2+ fluxes. Here we show that different types (static and extremely low-frequency, ELF pulsating) of MFs of different intensities alter plasma membrane potential. Interestingly, MFs induce plasma membrane hyperpolarization in cells sensitive to the antiapoptotic effect of MFs, whereas cells that are insensitive showed a plasma membrane depolarization. These opposite effects suggest that protection against apoptosis and membrane potential modulation are correlated, plasma membrane hyperpolarization possibly being part of the signal transduction chain determining MFs' antiapoptotic effect.

[Lack of direct cytotoxic effect of intracellular nanotubes]. / Impatto occupazionale ed ambientale dei nanotubi di carbonio, analisi della citotossicità su linee cellulari.

Nanotubes have a great therapeutic potential due to their astounding physico-chemical features, the possibility to be funtionalised for ad hoc uses, and the specific interaction of nanotubes as such with life molecules (DNA and proteins). These features recommend a thorough toxicological study before widespread pharmaceutic use. We provide evidence that culture cells with phagocytic potential internalise multi wall nanotubes (10-50 nm average size). This is not accompanied by cytotoxicity in terms of induction of &apoptosis or necrosis at the doses used (up to 125 microg/mI).

Oxidative Bax dimerization promotes its translocation to mitochondria independently of apoptosis.

Bax is a cytosolic protein, which in response to stressing apoptotic stimuli, is activated and translocates to mitochondria, thus initiating the intrinsic apoptotic pathway. In spite of many studies and the importance of the issue, the molecular mechanisms that trigger Bax translocation are still obscure. We show by computer simulation that the two cysteine residues of Bax may form disulfide bridges, producing conformational changes that favor Bax translocation. Oxidative, nonapoptogenic treatments produce an up-shift of Bax migration compatible with homodimerization, which is reverted by reducing agents; this is accompanied by translocation to mitochondria. Dimers also appear in pure cytosolic fractions of cell lysates treated with H2O2, showing that Bax dimerization may take place in the cytosol. Bax dimer-enriched lysates support Bax translocation to isolated mitochondria much more efficiently than untreated lysates, indicating that dimerization may promote Bax translocation. The absence of apoptosis in our system allows the demonstration that Bax moves because of oxidations, even in the absence of apoptosis. This provides the first evidence that Bax dimerization and translocation respond to oxidative stimuli, suggesting a novel role for Bax as a sensor of redox imbalance.

Hypoxic stress stably alters apoptotic parameters on U937 cells.

Tumor promonocytic U937 cells cultured under a low O(2)/high CO(2) atmosphere display altered characteristics after restoration of normal atmosphere: increased resistance to apoptosis induced by different treatments; apoptotic morphology; lack of glutathione (GSH) extrusion in apoptosis; lack of protection by antioxidants; and lack of Ca(2+) mobilization with thapsigargin. These alterations were stably maintained for many months of culture in normal conditions, originating the stable U937-HX variant. Since the hypoxic treatment did not produce a great selective pressure, the alterations are conceivably the result of stable adaptative response.

Apoptotic GSH extrusion is associated with free radical generation.

Reactive oxygen species (ROS) are involved in many forms of apoptosis and mediate apoptosis in a number of cell types. In this paper, we use a variant of U937 monocytic cells (U937 HX) that show different biochemical features with respect to standard U937. Apoptotic standard U937 extrude reduced glutathione (GSH) and generate free radicals concomitantly with loss of mitochondria transmembrane potential (mt Deltapsi). These events are correlated with the extrusion of intracellular GSH. Conversely, apoptotic U937 HX cells retain GSH, and the loss of mt Deltapsi is not accompanied by generation of free radicals. The perfect inverse correlation between (a) ROS generation and (b) the presence of intracellular GSH during apoptosis suggests novel mechanisms to finely tune ROS generation in apoptosis.

Clinical applications of 2D and 3D CT imaging of the airways--a review.

Hardware and software evolution has broadened the possibilities of 2D and 3D reformatting of spiral CT and MR data set. In the study of the thorax, intrinsic benefits of volumetric CT scanning and better quality of reconstructed images offer us the possibility to apply additional rendering techniques to everyday clinical practice. Considering the large number and redundancy of possible post-processing imaging techniques that we can apply to raw CT sections data, it is necessary to precisely set a well-defined number of clinical applications of each of them, by careful evaluation of their benefits and possible pitfalls in each clinical setting. In diagnostic evaluation of pathological processes affecting the airways, a huge number of thin sections is necessary for detailed appraisal and has to be evaluated, and information must then be transferred to referring clinicians. By additional rendering it is possible to make image evaluation and data transfer easier, faster, and more effective. In the study of central airways, additional rendering can be of interest for precise evaluation of the length, morphology, and degree of stenoses. It may help in depicting exactly the locoregional extent of central tumours by better display of relations with bronchovascular interfaces and can increase CT/bronchoscopy sinergy. It may allow closer radiotherapy planning and better depiction of air collections, and, finally, it could ease panoramic evaluation of the results of dynamic or functional studies, that are made possible by increased speed of spiral scanning. When applied to the evaluation of peripheral airways, as a completion to conventional HRCT scans, High-Resolution Volumetric CT, by projection slabs applied to target areas of interest, can better depict the profusion and extension of affected bronchial segments in bronchiectasis, influence the choice of different approaches for tissue sampling by better evaluation of the relations of lung nodules with the airways, or help to detect otherwise overlooked slight pathological findings. In the exploration of the air-spaces of the head and neck, targeted multiplanar study can now be performed without additional scanning by retro-reconstructed sections from original transverse CT slices. Additional rendering can help in surgical planning, by simulation of surgical approaches, and allows better integration with functional paranasal sinuses endoscopic surgery, by endoscopic perspective rendering. Whichever application we perform, the clinical value of 2D and 3D rendering techniques lies in the possibility of overcoming perceptual difficulties and 'slice pollution', by easing more efficient data transfer without loss of information. 3D imaging should not be considered, in the large majority of cases, as a diagnostic tool: looking at reformatted images may increase diagnostic accuracy in only very few cases, but an increase in diagnostic confidence could be not negligible. The purpose of the radiologist skilled in post-processing techniques should be that of modifying patient management, by more confident diagnostic evaluation, in a small number of patients, and, in a larger number of cases, by simplifying communication with referring physicians and surgeons. We will display in detail possible clinical applications of the different 2D and 3D imaging techniques, in the study of the tracheobronchial tree, larynx, nasal cavities and paranasal sinuses by Helical CT, review relating bibliography, and briefly discuss pitfalls and perspectives of CT rendering techniques for each field.