Correction: Zanin et al. Analysis of Radiation Toxicity in Mammalian Cells Stably Transduced with Mitochondrial Stat3. Int. J. Mol. Sci. 2023, 24, 8232

In the original publication [...].

STAT3 and HIF1α cooperatively mediate the transcriptional and physiological responses to hypoxia

STAT3 and HIF1α are two fundamental transcription factors involved in many merging processes, like angiogenesis, metabolism, and cell differentiation. Notably, under pathological conditions, the two factors have been shown to interact genetically, but both the molecular mechanisms underlying such interactions and their relevance under physiological conditions remain unclear. In mouse embryonic stem cells (ESCs) we manage to determine the specific subset of hypoxia-induced genes that need STAT3 to be properly transcribed and, among them, fundamental genes like Vegfa, Hk1, Hk2, Pfkp and Hilpda are worth mentioning. Unexpectedly, we also demonstrated that the absence of STAT3 does not affect the expression of Hif1α mRNA nor the stabilization of HIF1α protein, but the STAT3-driven regulation of the hypoxia-dependent subset of gene could rely on the physical interaction between STAT3 and HIF1α. To further elucidate the physiological roles of this STAT3 non-canonical nuclear activity, we used a CRISPR/Cas9 zebrafish stat3 knock-out line. Notably, hypoxia-related fluorescence of the hypoxia zebrafish reporter line (HRE:mCherry) cannot be induced when Stat3 is not active and, while Stat3 Y705 phosphorylation seems to have a pivotal role in this process, S727 does not affect the Stat3-dependent hypoxia response. Hypoxia is fundamental for vascularization, angiogenesis and immune cells mobilization; all processes that, surprisingly, cannot be induced by low oxygen levels when Stat3 is genetically ablated. All in all, here we report the specific STAT3/HIF1α-dependent subset of genes in vitro and, for the first time with an in vivo model, we determined some of the physiological roles of STAT3-hypoxia crosstalk.

Analysis of Radiation Toxicity in Mammalian Cells Stably Transduced with Mitochondrial Stat3

A coordinated action between nuclear and mitochondrial activities is essential for a proper cellular response to genotoxic stress. Several nuclear transcription factors, including STAT3, translocate to mitochondria to exert mitochondrial function regulation; however, the role of mitochondrial STAT3 (mitoSTAT3) under stressed conditions is still poorly understood. In this study, we examined whether the stable expression of mitoSTAT3 wild-type or mutated at the conserved serine residue (Ser727), which is involved in the mitochondrial function of STAT3, can affect the DNA damage response to UVC radiation. To address this issue, we generated mammalian cells (NIH-3T3 and HCT-116 cells) stably transduced to express the mitochondrial-targeted Stat3 gene in its wild-type or Ser727 mutated forms. Our results show that cell proliferation is enhanced in mitoStat3-transduced cells under both non-stressed and stressed conditions. Once irradiated with UVC, cells expressing wild-type mitoSTAT3 showed the highest cell survival, which was associated with a significant decrease in cell death. Low levels of oxidative stress were detected in UVC-irradiated NIH-3T3 cells expressing mitoSTAT3 wild-type or serine-related dominant active form (Ser727D), confirming a role of mitochondrial STAT3 in minimizing oxidant cellular stress that provides an advantage for cell survival.

Zebrafish ambra1b knockout reveals a novel role for Ambra1 in primordial germ cells survival, sex differentiation and reproduction

BACKGROUND

AMBRA1 is an intrinsically disordered protein, working as a scaffold molecule to coordinate, by protein-protein interaction, many cellular processes, including autophagy, mitophagy, apoptosis and cell cycle progression. The zebrafish genome contains two ambra1 paralogous genes (a and b), both involved in development and expressed at high levels in the gonads. Characterization of the zebrafish paralogous genes mutant lines generated by CRISPR/Cas9 approach showed that ambra1b knockout leads to an all-male population.

RESULTS

We demonstrated that the silencing of the ambra1b gene determines a reduction of primordial germ cells (PGCs), a condition that, in the zebrafish, leads to the development of all-male progeny. PGC reduction was confirmed by knockdown experiments and rescued by injection of ambra1b and human AMBRA1 mRNAs, but not ambra1a mRNA. Moreover, PGC loss was not rescued by injection with human AMBRA1 mRNA mutated in the CUL4-DDB1 binding region, thus suggesting that interaction with this complex is involved in PGC protection from loss. Results from zebrafish embryos injected with murine Stat3 mRNA and stat3 morpholino suggest that Ambra1b could indirectly regulate this protein through CUL4-DDB1 interaction. According to this, Ambra1^+/- mice showed a reduced Stat3 expression in the ovary together with a low number of antral follicles and an increase of atretic follicles, indicating a function of Ambra1 in the ovary of mammals as well. Moreover, in agreement with the high expression of these genes in the testis and ovary, we found significant impairment of the reproductive process and pathological alterations, including tumors, mainly limited to the gonads.

CONCLUSIONS

By exploiting ambra1a and ambra1b knockout zebrafish lines, we prove the sub-functionalization between the two paralogous zebrafish genes and uncover a novel function of Ambra1 in the protection from excessive PGC loss, which seems to require binding with the CUL4-DDB1 complex. Both genes seem to play a role in the regulation of reproductive physiology.

Y705 and S727 are required for the mitochondrial import and transcriptional activities of STAT3, and for regulation of stem cell proliferation

The STAT3 transcription factor, acting both in the nucleus and mitochondria, maintains embryonic stem cell pluripotency and promotes their proliferation. In this work, using zebrafish, we determined in vivo that mitochondrial STAT3 regulates mtDNA transcription in embryonic and larval stem cell niches and that this activity affects their proliferation rates. As a result, we demonstrated that import of STAT3 inside mitochondria requires Y705 phosphorylation by Jak, whereas its mitochondrial transcriptional activity, as well as its effect on proliferation, depends on the MAPK target S727. These data were confirmed using mouse embryonic stem cells: although the Y705-mutated STAT3 cannot enter mitochondria, the S727 mutation does not affect import into the organelle and is responsible for STAT3-dependent mitochondrial transcription. Surprisingly, STAT3-dependent increase of mitochondrial transcription appears to be independent from STAT3 binding to STAT3-responsive elements. Finally, loss-of-function experiments, with chemical inhibition of the JAK/STAT3 pathway or genetic ablation of stat3 gene, demonstrated that STAT3 is also required for cell proliferation in the intestine of zebrafish.

Summary: Mitochondrial import of STAT3 requires Y705 phosphorylation by Jak, whereas STAT3 mitochondrial transcriptional activity and its effect on proliferation depend on the MAPK target S727.

The stem-like Stat3-responsive cells of zebrafish intestine are Wnt/β-catenin dependent

The transcription factor Stat3 is required for proliferation and pluripotency of embryonic stem cells; we have prepared and characterized fluorescent Stat3-reporter zebrafish based on repeats of minimal responsive elements. These transgenic lines mimic in vivo Stat3 expression patterns and are responsive to exogenous Stat3; notably, fluorescence is inhibited by both stat3 knockout and IL6/Jak/STAT inhibitors. At larval stages, Stat3 reporter activity correlates with proliferating regions of the brain, haematopoietic tissue and intestine. In the adult gut, the reporter is active in sparse proliferating cells, located at the base of intestinal folds, expressing the stemness marker sox9b and having the morphology of mammalian crypt base columnar cells; noteworthy, zebrafish stat3 mutants show defects in intestinal folding. Stat3 reporter activity in the gut is abolished with mutation of T cell factor 4 (Tcf7l2), the intestinal mediator of Wnt/β-catenin-dependent transcription. The Wnt/β-catenin dependence of Stat3 activity in the gut is confirmed by abrupt expansion of Stat3-positive cells in intestinal adenomas of apc heterozygotes. Our findings indicate that Jak/Stat3 signalling is needed for intestinal stem cell maintenance and possibly crucial in controlling Wnt/β-catenin-dependent colorectal cancer cell proliferation.

Summary: Using a fluorescent reporter for Stat3 activity, we have identified the stem cells of zebrafish intestine and characterized their Wnt requirements and responsiveness.

Measuring recognition memory in zebrafish larvae: issues and limitations

Recognition memory is the capacity to recognize previously encountered objects, events or places. This ability is crucial for many fitness-related activities, and it appears very early in the development of several species. In the laboratory, recognition memory is most often investigated using the novel object recognition test (NORt), which exploits the tendency of most vertebrates to explore novel objects over familiar ones. Despite that the use of larval zebrafish is rapidly increasing in research on brain, cognition and neuropathologies, it is unknown whether larvae possess recognition memory and whether the NORt can be used to assess it. Here, we tested a NOR procedure in zebrafish larvae of 7-, 14- and 21-days post-fertilization (dpf) to investigate when recognition memory first appears during ontogeny. Overall, we found that larvae explored a novel stimulus longer than a familiar one. This response was fully significant only for 14-dpf larvae. A control experiment evidenced that larvae become neophobic at 21-dpf, which may explain the poor performance at this age. The preference for the novel stimulus was also affected by the type of stimulus, being significant with tri-dimensional objects varying in shape and bi-dimensional geometrical figures but not with objects differing in colour. Further analyses suggest that lack of effect for objects with different colours was due to spontaneous preference for one colour. This study highlights the presence of recognition memory in zebrafish larvae but also revealed non-cognitive factors that may hinder the application of NORt paradigms in the early developmental stages of zebrafish.

Zebrafish ambra1a and ambra1b Silencing Affect Heart Development

In zebrafish, two paralogous genes, activating molecule in beclin-1 (BECN1)-regulated autophagy ambra1a and ambra1b, both required for the autophagic process and during development, encode the protein AMBRA1, a positive regulator of early steps of autophagosome formation. As transcripts for both genes are expressed during embryogenesis in the heart region, in this work, we investigated the effects of ambra1a and ambra1b knockdown on heart development by means of morpholino oligonucleotides (MOs). Silencing of the two proteins by MOs directed against the ATG translation initiation codon affects cardiac morphogenesis, resulting in a small, string-like heart with pericardial edema, whereas treatment with splice-blocking MOs does not lead to overt cardiac phenotypes, thus revealing the relevance of maternally supplied ambra1 transcripts for heart development. Co-injection of both ATG-MOs determines a more severe cardiac phenotype, with prominent pericardial edema. Whole-mount in situ hybridization (WMISH) for myosin light chain 7 (myl7), as well as ambra1 ATG-MO microinjection in zebrafish transgenic line expressing green fluorescent protein in the heart, revealed defects with the heart jogging process followed by imperfect cardiac looping. Moreover, WMISH of homeodomain transcription factor 2 isoform c (pitx2c) transcripts showed both bilateral and reversed pitx2c expression in morphants. The morphants' cardiac phenotypes were effectively rescued by co-injection of MOs with human AMBRA1 (hAMBRA1) messenger RNA (mRNA), pointing at the conservation of Ambra1 functions during evolution. Co-injections of ambra1 ATG-MOs with a hAMBRA1 mRNA mutated in the protein phosphatase 2a (PP2A) binding sites (hAMBRA1PXP) were not able to rescue the cardiac phenotypes, at the difference from wild-type hAMBRA1 mRNA, and treatment of zebrafish embryos with the specific PP2A inhibitor cantharidin resulted in similar developmental cardiac defects. These results suggest a critical role for AMBRA1 in vertebrate heart development, likely involving the binding site for the PP2A phosphatase.

Reversible induction of mitophagy by an optogenetic bimodular system

Autophagy-mediated degradation of mitochondria (mitophagy) is a key process in cellular quality control. Although mitophagy impairment is involved in several patho-physiological conditions, valuable methods to induce mitophagy with low toxicity in vivo are still lacking. Herein, we describe a new optogenetic tool to stimulate mitophagy, based on light-dependent recruitment of pro-autophagy protein AMBRA1 to mitochondrial surface. Upon illumination, AMBRA1-RFP-sspB is efficiently relocated from the cytosol to mitochondria, where it reversibly mediates mito-aggresome formation and reduction of mitochondrial mass. Finally, as a proof of concept of the biomedical relevance of this method, we induced mitophagy in an in vitro model of neurotoxicity, fully preventing cell death, as well as in human T lymphocytes and in zebrafish in vivo. Given the unique features of this tool, we think it may turn out to be very useful for a wide range of both therapeutic and research applications.

Autophagic degradation of mitochondria (mitophagy) is a key quality control mechanism in cellular homeostasis, and its misregulation is involved in neurodegenerative diseases. Here the authors develop an optogenetic system for reversible induction of mitophagy and validate its use in cell culture and zebrafish embryos.

The epg5 knockout zebrafish line: a model to study Vici syndrome

The EPG5 protein is a RAB7A effector involved in fusion specificity between autophagosomes and late endosomes or lysosomes during macroautophagy/autophagy. Mutations in the human EPG5 gene cause a rare and severe multisystem disorder called Vici syndrome. In this work, we show that zebrafish epg5^-/- mutants from both heterozygous and incrossed homozygous matings are viable and can develop to the age of sexual maturity without conspicuous defects in external appearance. In agreement with the dysfunctional autophagy of Vici syndrome, western blot revealed higher levels of the Lc3-II autophagy marker in epg5^-/- mutants with respect to wild type controls. Moreover, starvation elicited higher accumulation of Lc3-II in epg5^-/- than in wild type larvae, together with a significant reduction of skeletal muscle birefringence. Accordingly, muscle ultrastructural analysis revealed accumulation of degradation-defective autolysosomes in starved epg5^-/- mutants. By aging, epg5^-/- mutants showed impaired motility and muscle thinning, together with accumulation of non-degradative autophagic vacuoles. Furthermore, epg5^-/- adults displayed morphological alterations in gonads and heart. These findings point at the zebrafish epg5 mutant as a valuable model for EPG5-related disorders, thus providing a new tool for dissecting the contribution of EPG5 on the onset and progression of Vici syndrome as well as for the screening of autophagy-stimulating drugs. Abbreviations: ATG: autophagy related; cDNA: complementary DNA; DIG: digoxigenin; dpf: days post-fertilization; EGFP: enhanced green fluorescent protein; EPG: ectopic P granules; GFP: green fluorescent protein; hpf: hours post-fertilization; IL1B: interleukin 1 beta; Lc3-II: lipidated Lc3; mpf: months post-fertilization; mRNA: messenger RNA; NMD: nonsense-mediated mRNA decay; PCR: polymerase chain reaction; qPCR: real time-polymerase chain reaction; RAB7A/RAB7: RAB7a, member RAS oncogene family; RACE: rapid amplification of cDNA ends; RFP: red fluorescent protein; RT-PCR: reverse transcriptase-polymerase chain reaction; SEM: standard error of the mean; sgRNA: guide RNA; UTR: untranslated region; WMISH: whole mount in situ hybridization; WT: wild type.

The zebrafish orthologue of the human hepatocerebral disease gene MPV17 plays pleiotropic roles in mitochondria

Mitochondrial DNA depletion syndromes (MDS) are a group of rare autosomal recessive disorders with early onset and no cure available. MDS are caused by mutations in nuclear genes involved in mitochondrial DNA (mtDNA) maintenance, and characterized by both a strong reduction in mtDNA content and severe mitochondrial defects in affected tissues. Mutations in MPV17, a nuclear gene encoding a mitochondrial inner membrane protein, have been associated with hepatocerebral forms of MDS. The zebrafish mpv17 null mutant lacks the guanine-based reflective skin cells named iridophores and represents a promising model to clarify the role of Mpv17. In this study, we characterized the mitochondrial phenotype of mpv17^−/− larvae and found early and severe ultrastructural alterations in liver mitochondria, as well as significant impairment of the respiratory chain, leading to activation of the mitochondrial quality control. Our results provide evidence for zebrafish Mpv17 being essential for maintaining mitochondrial structure and functionality, while its effects on mtDNA copy number seem to be subordinate. Considering that a role in nucleotide availability had already been postulated for MPV17, that embryos blocked in pyrimidine synthesis do phenocopy mpv17^−/− knockouts (KOs) and that mpv17^−/− KOs have impaired Dihydroorotate dehydrogenase activity, we provided mpv17 mutants with the pyrimidine precursor orotic acid (OA). Treatment with OA, an easily available food supplement, significantly increased both iridophore number and mtDNA content in mpv17^−/− mutants, thus linking the loss of Mpv17 to pyrimidine de novo synthesis and opening a new simple therapeutic approach for MPV17-related MDS.

Summary: The zebrafish mpv17^−/− mutant shows a severe mitochondrial phenotype with ultrastructural alterations and oxidative phosphorylation impairment. The pyrimidine precursor orotic acid ameliorates mpv17^−/− phenotype and increases mitochondrial DNA content, linking the loss of Mpv17 to pyrimidine de novo synthesis.

Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The transfer line enables the unstable isotopes generated by the (238)U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

Zebrafish ambra1a and ambra1b knockdown impairs skeletal muscle development

The essential role of autophagy in muscle homeostasis has been clearly demonstrated by phenotype analysis of mice with muscle-specific inactivation of genes encoding autophagy-related proteins. Ambra1 is a key component of the Beclin 1 complex and, in zebrafish, it is encoded by two paralogous genes, ambra1a and ambra1b, both required for normal embryogenesis and larval development. In this study we focused on the function of Ambra1, a positive regulator of the autophagic process, during skeletal muscle development by means of morpholino (MO)-mediated knockdown and compared the phenotype of zebrafish Ambra1-depleted embryos with that of Ambra1^gt/gt mouse embryos. Morphological analysis of zebrafish morphant embryos revealed that silencing of ambra1 impairs locomotor activity and muscle development, as well as myoD1 expression. Skeletal muscles in ATG-morphant embryos displayed severe histopathological changes and contained only small areas of organized myofibrils that were widely dispersed throughout the cell. Double knockdown of ambra1a and ambra1b resulted in a more severe phenotype whereas defects were much less evident in splice-morphants. The morphants phenotypes were effectively rescued by co-injection with human AMBRA1 mRNA. Together, these results indicate that ambra1a and ambra1b are required for the correct development and morphogenesis of skeletal muscle.

Heritability of arterial stiffness and carotid intima-media thickness: an Italian twin study

BACKGROUND AND AIMS

Carotid intima-media thickness (IMT) and arterial stiffness parameters, including aortic augmentation index (AIx) and pulse wave velocity (PWV), are independent predictors of stroke and cardiovascular disease. Genetic effects on these traits were never explored in a Mediterranean country. The present study aims to quantify the contribution of genes, environment and age to carotid IMT and aortic Aix and PWV.

METHODS AND RESULTS

The twin design was used. A total of 348 adult twins from the Italian Twin Register underwent measurements of carotid IMT and aortic PWV and AIx in three university hospitals located in Rome, Padua and Perugia. Carotid IMT was measured by B-mode ultrasound, aortic PWV and AIx by Arteriograph. Genetic modelling was performed to decompose total variance of traits into genetic, shared and unshared environmental and age components. For each phenotype, the best-fitting model included additive genetic, unshared environmental and age effects. For IMT, heritability was 0.32 (95% confidence interval (CI): 0.25-0.38), unshared environmental component was 0.25 (0.18-0.32) and age contribution was 0.44 (0.39-0.49). For AIx and PWV, heritabilities were 0.42 (0.29-0.55) and 0.49 (0.35-0.62), unshared environmental components were 0.31 (0.22-0.44) and 0.37 (0.26-0.51) and age contributions were 0.27 (0.16-0.39) and 0.14 (0.06-0.24), respectively.

CONCLUSION

This study shows substantial genetic and unshared environmental influences on carotid intima-media thickness and arterial stiffness and confirms the relevant role of age in the aetiology of these traits. Further support is provided for prevention and health promotion strategies based on modifiable factors.

Ongoing characterization of the forced electron beam induced arc discharge ion source for the selective production of exotic species facility

An intense research and development activity to finalize the design of the target ion source system for the selective production of exotic species (SPES) facility (operating according to the isotope separation on line technique) is at present ongoing at Legnaro National Laboratories. In particular, the characterization of ion sources in terms of ionization efficiency and transversal emittance is currently in progress, and a preliminary set of data is already available. In this work, the off-line ionization efficiency and emittance measurements for the SPES forced electron beam induced arc discharge ion source in the case of a stable Ar beam are presented in detail.

Off-line ionization tests using the surface and the plasma ion sources of the SPES project

The development of new target ion source systems for the selective production of exotic species (SPES) facility is currently in progress at Legnaro National Laboratories. In this context, the study of ion sources and their performance in terms of ionization efficiency and transversal emittance is a crucial point in order to maximize the available yields, particularly for short-lived isotopes. In this work, preliminary off-line ionization efficiency and emittance measurements for the SPES surface and plasma ion sources are presented. The plasma source emittance measurements are supported by dedicated numerical calculations.

Cerebral distribution of white matter lesions in migraine with aura patients

OBJECTIVE

The objective of the study was to compare the cerebral distribution of white matter lesions (WMLs) between migraine patients with different aura symptoms.

METHODS

Migraine with aura (MA) patients were consecutively enrolled as part of the Shunt-Associated Migraine (SAM) study. According to clinical symptoms, aura was classified as motor, aphasic, sensory, visual or vertebrobasilar. Standard and FLAIR (fluid attenuated inversion recovery) T(2)-weighted MRI sequences were inspected for WMLs by three independent raters blinded to clinical data. WMLs were assessed in the periventricular areas (PV-WMLs) with the Fazekas scale and in the deep white matter (D-WMLs) with the Schelten's scale. Interobserver agreement was good to excellent (k = 0.64 to 0.96, p < .0001).

RESULTS

One hundred and eighty-five patients (77% women) were included. Aura symptoms were classified as visual in 172 (99%) patients, sensory in 76 (42%), aphasic in 54 (30%), motor in 39 (21%) and vertebrobasilar in 17 (9%) patients. One hundred and four patients (57%) exhibited more than one type of aura. D-WMLs were mainly detected in the frontal lobes (86%). There was no association between type of aura and the presence of WMLs in any cerebral location.

CONCLUSION

Aura symptoms do not influence the cerebral distribution of WMLs associated with migraine disease.

Is migraine associated with right-to-left shunt a separate disease? Results of the SAM study

Migraine with aura (MA) is associated with the persistence of patent foramen ovale (PFO) in about 50% of cases, and migraineurs tend to have larger shunts than controls, suggesting that right-to-left shunt (RILES) determined by PFO could play a role in triggering migraine attacks. Moreover, some preliminary reports have suggested that PFO closure may give relief to both migraine and aura attacks. The aim of this study was to clarify if shunt-associated migraine (SAM) has clinical features that allow a distinction from shunt-unrelated migraine (SUM), in a prospective, multicentre, observational study (SAM study). We enrolled consecutive MA patients, who underwent a structured, standardized questionnaire for family and personal history and for detailed migraine features. All were systematically screened for RILES with transcranial Doppler, and for coagulation disorders. Overall, 460 patients were included; the SUM and SAM classes comprised 58% and 42% of patients, respectively. SAM patients were significantly younger (34.1 +/- 10 vs. 37.1 +/- 11 years), had a more frequent family history of migraine (76% vs. 66%) and a higher frequency of sensory symptoms of aura (51% vs. 41%); by contrast, there was a lesser association of SAM with other cardiac abnormalities and with coagulation disorders. The SAM study suggests that the effect of RILES on migraine features is not relevant. The higher family history of migraine in SAM suggests a possible genetic linkage between migraine and RILES.

Low ankle-brachial index predicts an adverse 1-year outcome after acute coronary and cerebrovascular events

BACKGROUND

Low ankle-brachial Index (ABI) identifies patients with symptomatic and asymptomatic peripheral arterial disease. The aim of this study was to correlate ABI value (normal or low) with 1-year clinical outcome in patients hospitalized for acute coronary syndromes or cerebrovascular diseases (CVD).

METHODS

ABI was measured in consecutive patients hospitalized because of acute myocardial infarction, unstable angina, stroke or transient ischemic attack (TIA). An ABI lower than or equal to 0.90 was considered abnormal. The primary outcome of the study was the composite of non-fatal acute myocardial infarction, non-fatal ischemic stroke, and death from any cause during the year following the index event.

RESULTS

An abnormal ABI was found in 27.2% of 1003 patients with acute coronary syndromes, and in 33.5% of 755 patients with acute CVD. After a median follow-up of 372 days, the frequency of the primary outcome was 10.8% (57/526) in patients with abnormal ABI and 5.9% (73/1232) in patients with normal ABI [odds ratio (OR) 1.96; 95% CI 1.36-2.81]. Death was more common in patients with abnormal ABI (OR 2.05; 95% CI 1.31-3.22). Cardiovascular mortality accounted for 81.7% of overall mortality. ABI was predictive of adverse outcome after adjustment for vascular risk factors in the logistic regression analysis (OR 1.93; 95% CI 1.24-3.01). The predictive value of ABI was mainly accounted for by patients hospitalized for acute coronary syndromes (adverse outcome: 12.8% in patients with abnormal ABI and 5.9% in patients with normal ABI, OR 2.35; 95% CI 1.47-3.76).

CONCLUSIONS

An abnormal ABI can be found in one-third of patients hospitalized for acute coronary or cerebrovascular events and is a predictor of an adverse 1-year outcome.

Symptomatic and asymptomatic carotid artery lesions in peripheral vascular disease: a prospective study

PURPOSE

To assess the incidence and severity of internal carotid artery lesions in patients who were referred to a single institution with peripheral obliterative atherosclerotic disease (POAD) as their chief complaint, in order to identify symptomatic and asymptomatic subjects at risk of stroke who would benefit from surgery.

MATERIALS AND METHODS

Consecutive patients with clinically and Doppler scan-proven POAD underwent prospective screening for the presence of carotid symptomatic and asymptomatic atherosclerotic lesions with duplex ultrasound scan (DUS). Associated risk factors for atherosclerosis, i.e. age, sex, diabetes, hypertension, hyperlipidemia, history of smoking and history of coronary artery disease were assessed and recorded. Univariate analysis was performed to correlate the risk factors with the presence of POAD and carotid lesions.

RESULTS

Three-hundred and twelve consecutive patients were evaluated over an 18-month period. A 30% or greater carotid stenosis was detected by DUS in 189 patients (19 bilateral); 57 (30%) of these had neurologic symptoms, 19 of whom had a 70-99% carotid lesion, whereas 65 of the 132 asymptomatic patients had 60-99% carotid stenosis. Univariate analysis revealed no differences in the symptomatic and asymptomatic groups between patients who were potential candidates for carotid endarterectomy according to the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerotic Study Group guidelines, respectively, and those who were not as regards associated atherosclerotic risk factors and severity of POAD. All but 2 (n = 17) symptomatic and 18 asymptomatic patients underwent carotid endarterectomy based on DUS criteria alone. The perioperative stroke risk and mortality rates were 0%.

CONCLUSIONS

Routine carotid DUS screening of 312 consecutive patients with POAD revealed that 19 patients with symptoms and 65 (5 bilateral) without symptoms would benefit from surgery, representing 27% of the series considered.

Assessment of atherosclerosis using carotid ultrasonography in a cohort of HIV-positive patients treated with protease inhibitors

OBJECTIVE

Lipid disorders associated with the use of protease inhibitors (PI) may be a risk factor for premature atherosclerosis development. The aim of this study is to evaluate the extent of carotid intima media thickness (IMT) among HIV-positive patients treated with PI containing regimens compared to PI-naïve and HIV-negative subjects.

METHODS

We analysed plasma lipid levels and carotid IMT in 28 HIV-positive patients treated with protease inhibitors (PIs) for a mean of 28.7 months (range 18-43) and in two control groups constituted, respectively, by 15 HIV-positive naïve patients and 16 HIV-negative subjects, that were matched for age, risk factors for HIV infection, cigarette smoke use and CD4+ cell count.

RESULTS

PI-treated patients had higher triglyceride, HDL and apo B levels than controls. Carotid IMT was significantly increased in PI-treated patients compared to naïve or HIV-negative subjects. A correlation between cholesterol HDL, triglyceride and ApoB levels and IMT was observed among the entire cohort.

CONCLUSIONS

Plasma lipid alterations were associated with an increased IMT and intima media thickening was more pronounced in PI-treated patients than in the two control groups. Periodical evaluation of blood lipid profile and, if required, the use of lipid-lowering agents is advisable. Moreover, physicians should address concurrent risk factor for atherosclerosis that can be modified, including smoking, hypertension, obesity and sedentary life-style.

The quest for early predictors of stroke evolution: can TCD be a guiding light?

BACKGROUND AND PURPOSE

The present study aimed at evaluating the prognostic value of transcranial Doppler ultrasonography (TCD) in the acute phase of ischemic stroke, when major therapeutic decisions must be made.

METHODS

Seventy-three patients with a first-ever ischemic hemispheric stroke underwent neurological assessment according to the Unified Neurological Stroke Scale, clinical subgrouping according to the criteria of Bamford, CT scan, cervical duplex sonography, and TCD, all within 12 hours from stroke onset. TCD was repeated on days 2 and 7. Patients were followed for 90 days, during which we calculated the fatality rate and then assessed clinical outcome.

RESULTS

Emergency TCD revealed middle cerebral artery (MCA) no-flow in 24 cases and MCA asymmetry in 30 subjects. Serial TCD showed early (<24 hours) MCA recanalization in 6 patients. After 90 days, no patient with MCA occlusion at admission was autonomous, while 17 of 19 patients (89.5%) with a normal baseline TCD were independent. The fatality rate at 3 months was 21% but was 46% in patients with MCA occlusion and 61% in patients without signs of early MCA recanalization. Total anterior circulation infarct and abnormal TCD were significantly correlated (P:<0.001) with higher mortality rate and worse outcome (Barthel Index score </=60), whereas early CT ischemic signs and severe carotid disease were not. Furthermore, TCD identified within the total anterior circulation infarct subgroup 2 prognostic clusters according to MCA patency at admission (P:<0.001). Logistic regression selected normal baseline TCD as an independent predictor of good long-term outcome and MCA no-flow as an independent predictor of disability or death.

CONCLUSIONS

TCD findings play an important role in the early prognosis of anterior circulation stroke, providing possible guidance for therapeutic interventions.

Cerebral perfusion in hypertensives with carotid artery stenosis: a comparative study of lacidipine and hydrochlorothiazide

Focal cerebral hypoperfusion is a common finding in uncomplicated hypertensives even in the absence of large vessel atherosclerosis, and neuropsychological deficits correlate with cerebral hypoperfusion in hypertensive patients with cerebral microangiopathy. We investigated the effects on cerebral perfusion of the dihydropiridine calcium antagonist lacidipine and of hydrochlorothiazide (HCTZ) in asymptomatic hypertensive patients with concomitant atherosclerosis of the carotid arteries. Fifteen essential hypertensives (including 13 males, aged 55-75 years) with at least one 30-60% stenosis of the internal carotid artery at echo-color Doppler examination were treated in a double-blind, randomized, parallel study with lacidipine (4-6 mg od) or HCTZ (25-50 mg od) for 3 months after a 4-week single-blind placebo period. Regional cerebral perfusion was assessed at baseline and at the end of the treatment period with HMPAO-SPECT. Relative perfusion of cortical and subcortical areas was calculated as the ratio between their tracer activity and that of the cerebellum. At baseline, mean relative perfusion (MRP) of the cortical and subcortical areas was similar in the stenotic and the contralateral side. Despite the fall in pressure, lacidipine increased MRP both in the cortical and in the subcortical areas, whereas HCTZ increased MRP only in the cortical areas. The mean change in local vascular resistance, adjusted for initial perfusion value, was -20 A.U. (arbitrary unit) with lacidipine and -12 A.U. with HCTZ (p < 0.001). These differential effects of antihypertensive drugs on subcortical perfusion may be of benefit in the long-term prevention of vascular dementia in hypertensive patients.

Early detection of melanoma: an educational campaign in Padova, Italy

To evaluate a public campaign for the early referral and treatment of cutaneous melanoma, an educational programme based on self-selection by subjects was organized in Padova, Italy in 1991. In the period from 1991 to 1996, 90,000 leaflets containing information on naevi, melanoma and skin self-examination were mailed to each household, reaching a population of 243,000 subjects. A total of 2050 individuals requested a skin check as a result of the leaflet. Most were at low risk, the majority being female (68%) and aged under 40 years (51.6%), with no risk factors (58.3%). One hundred and ninety subjects were referred for surgery for pigmented and non-pigmented suspect lesions. Histological diagnoses, obtained for all lesions, comprised 13 melanomas, 17 dysplastic naevi, 17 basocellular carcinomas, 140 pigmented benign lesions and three lesions of other types. The percentage of thin melanomas (< 1.50 mm) was 92.3%. Three hundred and fifty patients considered at risk at the first skin examination attended regular follow-up examinations. The sensitivity and predictive positive value of the visual examination were 92.8% and 6.8%, respectively. The impact of this campaign was evaluated in the Local Health District of Padova, comparing data from the pre-campaign period (1987-1990) with those from the campaign period (1991-1996); a trend towards a lower stage was observed (mean thickness 2.0 mm versus 1.50 mm; P < 0.02).

Carotid endarterectomy in women: early and long-term results

BACKGROUND

Although many randomized trials and other multicenter studies have demonstrated the benefits of carotid endarterectomy (CEA) in selected symptomatic and asymptomatic patients, including women, there is a remarkable lack of reports regarding the outcome of CEA with respect to sex. To analyze and compare the outcome of CEA in men and women in a single-group experience, we reviewed a consecutive series of 619 CEAs performed in 539 patients, 371 men (423 CEAs) and 168 women (196 CEAs).

METHODS

Data collection was retrospective up to August 1, 1992 and prospective for all 405 patients treated thereafter.

RESULTS

Women were significantly less likely than men to have overt evidence of coronary artery disease (P < .001) and had a significantly higher incidence of diabetes (P < .001). No perioperative death occurred in the female group (P = NS), and no statistical difference was found in perioperative stroke risk incidence. Women had a significantly higher incidence of late occlusive events (P = .01), which were all asymptomatic. No late stroke occurred in the female group (P = NS). Life-table cumulative survival rates at 1, 3, 5, and 7 years were 99.3%, 90.5%, 85.9%, and 82.3%, respectively, in women, and 98.9%, 91.9%, 85.2%, and 79.6% in men (log-rang P = .8).

CONCLUSIONS

These findings show that perioperative stroke risk and mortality rates, as well as late stroke-free, mortality, and recurrence rates, in patients undergoing CEA, are comparable in men and women. Further, larger comparative studies are necessary to provide more information on the benefit and durability of CEA in asymptomatic patients, but the results of this study suggest that the early and late outcomes are excellent and comparable in symptomatic and asymptomatic men and women.

Carotid endarterectomy without angiography: can clinical evaluation and duplex ultrasonographic scanning alone replace traditional arteriography for carotid surgery workup? A prospective study

BACKGROUND

The aim of this study was to determine whether clinical evaluation and duplex ultrasonography (DUS) alone can replace contrast cerebral arteriography (CA) for the detection of patients suitable for surgery at our institution.

METHODS

During an 18-month period, 100 patients underwent DUS and CA during evaluation for carotid endarterectomy (CEA). All patients were studied prospectively; in each case an initial decision for or against CEA on the basis of DUS evaluation of the internal carotid arteries (ICAs) was subsequently compared with the surgeon's final management plan after CA. Of the 200 ICAs evaluated, 113 were considered for CEA but 14 were excluded from the study because the patient could not be evaluated before and after CA. This left 99 ICAs (86 patients) available for comparative analysis.

RESULTS

The outcome of the 2 diagnostic modalities was perfectly consistent in 95.3% of the ICAs (kappa = 0.969). The clinical management decision was altered by the CA findings in only 2 cases (2%). Of the 99 ICAs considered suitable, 97 underwent CEA. No arteriographic complications occurred among the 100 patients undergoing CA. The perioperative stroke risk and mortality rates were 0%.

CONCLUSIONS

Ninety-eight percent of the ICAs considered for surgery would have received appropriate clinical treatment on the strength of the patients' neurologic history and the outcome of DUS alone. Our results indicate that DUS is sufficient to establish the need for surgery in symptomatic and asymptomatic patients being considered for CEA and can replace CA in most clinical circumstances.

Cranial and cervical nerve injuries after carotid endarterectomy: a prospective study

BACKGROUND

The purpose of this study was to review the outcome of patients who had cranial and cervical nerve injuries after carotid endarterectomy (CEA).

METHODS

This prospective study reviewed 200 consecutive CEAs. Preoperative and postoperative cranial nerve assessment was completed on all patients. Neurologic evaluation included routine direct fiberoptic laryngoscopy. Patients found to have no neurologic injury had no further follow-up. Patients with postoperative peripheral neurologic dysfunction were enrolled for regular long-term follow-up to assess delayed recovery.

RESULTS

Overall, 25 (12.5%) nerve injuries were identified in 24 patients. There were 11 (5.5%) hypoglossal, 8 (4%) recurrent laryngeal, 2 (1%) superior laryngeal, 2 (1%) marginal mandibular, and 2 (1%) greater auricular nerve injuries. None of the patients were lost to follow-up. All nerve dysfunctions were transient, with all but 4 nerves recovering completely within 6 months. The recovery took from 1 week to 37 months, with a mean recovery time of 5.8 months. Two patients with recurrent laryngeal nerve dysfunction were found to have prolonged full recovery time (i.e., 31 and 37 months, respectively). Two patients successfully underwent contralateral CEA, although movement of the opposite vocal cord was not fully restored.

CONCLUSIONS

Cranial nerve injury after CEA is a common occurrence and can be classified as a "major" or "minor" complication, depending on the severity of the clinical consequences. Extended follow-up will identify the specific subset of patients with a late complete nerve recovery.

Results of electroencephalographic monitoring during 369 consecutive carotid artery revascularizations

A continuous intraoperative EEG monitoring was performed in 369 consecutive carotid artery revascularizations (CARs) (321 patients) to minimize the intraoperative neurological morbidity. There were 227 carotid endarterectomies and patch graft angioplasty (198 patients), 79 carotid eversion endarterectomies (70 patients) and 58 internal carotid artery reimplantations into the common carotid artery (48 patients). Indications for CARs were TIAs (141, 43.9%), amaurosis fugax (60, 18.6%) and fixed or partial nonprogressing stroke (14, 4.3%). One hundred and six patients (33.1%) were asymptomatic. EEG abnormalities consistent with cerebral ischemia occurred in 97 (26.3%) operations. The indwelling shunt (IS) was used in 73 cases; in the remaining 24 (24.7%), IS was not used on purpose because the surgical procedure was carried out successfully within 5-6 min after the appearance of EEG changes. All patients awoke from the anesthesia without any neurological deficit. Five patients presented with a major stroke within postoperative day 1 and 2, and 1 patient died on postoperative day 10. In 2 of these cases, the intraoperative EEG monitoring was absolutely normal and the IS was not used: the carotid occlusion was due to technical errors. The most striking finding of this series is the absence of false-negative results in continuous EEG monitoring. EEG monitoring appears an available and useful method for the detection of cerebral ischemia secondary to carotid cross-clamping and contributes to put at zero the intraoperative complications of the surgical procedure.

[Idiopathic cupulolithiasis: vasomotor reactivity evaluation of the vertebro-basilar artery by transcranial doppler ultrasonography and acetazolamide test]

Benign paroxysmal positional vertigo (BPPV) or cupulolithiasis is one of the more common peripheral vestibular disorders. Diagnosis is made on the observation of typical positioning nystagmus brought about by the Hallpike manoeuver. In most cases of BPPV, etiology is unknown. Microcirculatory disorders have often been considered responsible for idiopathic BPPV. Few reports have been published on this specific aspect of the problem. In our study we evaluated vertebro-basilar haemodynamics and vasomotory reactivity after Acetazolamide administration in 12 patients with idiopathic BPPV. The results obtained reveal the absence of macrocirculatory impairment in the vertebro-basilar district in basal conditions, but significative vasoreactivity variation after acetazolamide, both in vertebral and basilar arteries. Poor vasomotor reactivity in one vertebral artery was observed in 5 patients and, in two cases, in the basilar artery. Altered vasoreactivity in the middle cerebral arteries was not observed in any case. In the light of these findings, we suggest that a possible inadequate response if microcirculation in the labyrinth, in some particular haemodynamic situations, might cause otolithic damage.

[Carotid stenosis and obliteration of the contralateral carotid. A prospective study of the risks of a carotid endarterectomy intervention and its long-term results]

From March 1980 to July 1988 a consecutive series of 256 patients (p.) underwent 301 carotid endarterectomy + patch with routine use of continuous intraoperative EEG monitoring and selective use of an intraluminal shunt (IS) for the presence of an atherosclerotic plaque concerning the internal carotid artery (ICA). Patients were divided in two groups: the first (42 p.) marked by contralateral ICA occlusion, the second (214 p.) without contralateral ICA occlusion (259 CEA). Immediate peroperative, long term and global (immediate and long term) outcomes were prospectively and comparatively studied. A temporary IS was inserted in 27 p. (64%) of the group I and in 38 p. (14%) of the group II. Immediate permanent postoperative neurological deficit occurred in 1 p. of group I (2.38%) and in 2 p. (0.9%) in group II. Immediate postoperative mortality was 0% and 0.9% in group I and II respectively. All p. had neurological valuation and Echo-Doppler of operated ICA and of the contralateral ICA every 6 months (middle follow-up 44 months). New neurological symptoms compared in 5.8% of p. of group I and in 5.23% of p. of group II with a stroke rate of 0% and 2.32% respectively. There were 2 restenosis of operated ICA, both of them in p. of group I, that underwent reoperation. In the two groups the principal causes of deaths were myocardial infarct and cancer; in the group I no death was due to stroke versus 1.86% in the group II.

Hyperbaric oxygen therapy in the treatment of multiple sclerosis. A clinical and electrophysiological study in a 2 year follow-up

15 patients with chronic progressive Multiple Sclerosis were treated with Hyperbaric Oxygen Therapy at 2.0 atmospheres absolute for a total of 20 daily exposures followed by 2 exposures every month. The treatment was carried out for a 24 months follow-up. No objective benefit resulted from Hyperbaric Oxygen Therapy at the completion of the study while a subjective improvement in bladder control was reported in the short and in the long-term follow-up by 8 and by 5 patients respectively. No significant variations in the electrophysiological results were observed after the first 20 consecutive exposures. It is concluded from this trial that a long-term Hyperbaric Oxygen Treatment cannot moderate the progression of Multiple Sclerosis. However, an improvement in the quality of life can be obtained in some patients resulting from a better control of bladder function.

[Type I Arnold-Chiari malformation: diagnostic considerations in a case]

An 18-year-old patient with a 5-year history of periodic vertigo, headache and stiff neck is reported. Routine X-ray of the skull showed a mild form of basilar impression while the CT scan demonstrated only a tri-ventricular hydrocephalus. Without using the traditional invasive techniques, diagnosis of Chiari type I malformation was nonetheless clearly pointed out by magnetic resonance imaging of the posterior fossa and spinal cord. Diagnostic problems of this clinically ambiguous and uncharacterized syndrome are discussed.

EEG monitoring, selective shunting and patch graft angioplasty in carotid endarterectomy. Early and longterm results

From March 1980 to July 1986 at the Department of Vascular Surgery of the University of Padua, 182 patients underwent 210 carotid revascularizations for atherosclerotic stenosis involving the carotid bifurcation (28 operations were bilateral). Carotid endarterectomies (CE) and patch graft angioplasty totalled 192 (166 patients); an enlarging patch graft angioplasty of the internal carotid artery (ICA) without CE was performed in 14 cases (13 patients); in the remaining four surgical procedures (3 patients), for technical reasons prohibiting CE, the operation consisted of a great saphenous vein bypass between a donor vessel and the ICA distal to the lesion. The preoperative symptoms in 182 patients were as follows: TIAs (98 cases, 54%), non-hemispheric symptoms (21 cases (12%) and fixed stroke or TIAIR (10 cases, 5%). Fifty-three patients (29%) were asymptomatic. In all cases, continuous EEG monitoring was employed. The operation was performed without a temporary intraluminal shunt in the patients showing tolerance to carotid clamping. The protection of the shunt was required only in patients with EEG changes (47 cases). The arteriotomy was routinely closed with a PTFE patch graft angioplasty. Early results of the operation were excellent: none of the patients presented permanent or transient neurological deficits in the immediate postoperative period and none of them died. All patients were reassessed with C.W. Doppler sonography and Duplex scanning in the postoperative period. In all cases, the success of the operation was demonstrated. Longterm follow-up (6-72 months, mean follow-up: 35 months) was done in 121 patients (142 operations): 107 patients were completely asymptomatic, 5 remained stable or slightly improved the preoperative status. Five patients had a new or recurrent TIAs, 3 suffered a stroke, one showed a recurrence of non-hemispheric symptoms. With the exception of two patients suffering a stroke, all had a second arteriography but none of these patients showed extracranial lesions. Two patients presented an asymptomatic restenosis of the ICA. Eight patients (8.8%) revealed a significant evolution of the disease of the contralateral unoperated ICA.(ABSTRACT TRUNCATED AT 400 WORDS)

[Continuous EEG monitoring in carotid surgery]

From March 1980 to March 1987, at the Department of Vascular Surgery of the University of Padua, 217 patients underwent 252 carotid revascularizations with routine use of an intraluminal shunt (IS) for symptomatic (70%) or asymptomatic (30%) internal carotid artery (ICA) atherosclerotic stenosis. All carotid endarterectomies (CEs) were routinely performed with patch graft angioplasty to prevent restenosis. In the immediate post-operative period, no patient presented permanent or transient neurological deficits; no patient died. In the early post-operative course there was a 0.9% (2 patients) stroke rate and 0.4% (1 patient) mortality rate. These results suggest that the selective use of the IS on the basis of EEG changes is able to reduce the perioperative morbidity and mortality to nearly zero.

Pineal germinoma: diagnosis, treatment and tumor response

We report the case of pineal germinoma in a 25 year old man. The neurological signs and symptoms were insidious in onset; Parinaud syndrome allowed a topical diagnosis, confirmed by CT scan. Computerized Tomography and CSF cytological examination were of the utmost importance to diagnosis and treatment and it confirmed the success of radiotherapy.