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1.
Crim Behav Ment Health ; 33(5): 342-353, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37695266

ABSTRACT

BACKGROUND: Screening for mental disorders among prisoners is crucial for early detection and intervention of psychopathology and substance use disorders. In Italy, only a minority of prisons have implemented a structured screening process, and there is not yet a standard approach to this worldwide. AIMS: First, to describe a systematic psychological screening for early identification of mental disorder, including drug use disorders, and suicide risk among men on reception into one Italian prison, designed to inform management and, secondly, to describe mental health outcomes among those prisoners accepted into the in-reach mental health service as a result of the assessment. METHODS: All prisoners newly received in the Parma Penitentiary Institute at any time in 2020 were screened using the Jail Screening Assessment Tool. Those who screened positive for any mental disorder, including substance use disorders and suicide indicators, were asked to complete the Parma Scale for the treatment evaluation of offenders with psychiatric disorders (Pr-Scale), a locally developed tool that allows for the measurement of mental state change as well as changes in treatment and management. Scores on this scale soon after reception were compared with scores after 1 year of work with the in-reach team. RESULTS: Among 303 newly admitted male prisoners in 2020, 167 (55%) screened positive for substance use disorder and 30 (10%) for other primary mental disorders. Most of these (n = 151) were offered and accepted care by the mental health in-reach service. After 1 year, those who had been treated by this service showed significant improvement in all Pr-Scale clinical variables. CONCLUSIONS: Our findings support the extension of a psychological screening into a service for new receptions to Italian prisons. They add evidence for the utility of the Pr-Scale for detecting those newly admitted prisoners likely to benefit from early mental health interventions provided by in-reach services and for evidencing resultant change. Future studies are needed to replicate our results in other Italian prisons as a precursor to systems improvement, while other countries might also benefit from using similar evaluation and reevaluation routinely.

2.
Animals (Basel) ; 13(18)2023 Sep 20.
Article in English | MEDLINE | ID: mdl-37760366

ABSTRACT

We assessed the effects of inhalation administration of lavender essential oil (LEO) either once (L1) or twice (L2) a day on animal welfare indicators, carcass and meat quality of Italian heavy pigs. Pigs (n = 108) were allotted to three experimental groups (control -C-, L1 and L2) and lavender was administered, via a vaporizer device, to the treated groups during the entire fattening-finishing period (79-160 kg BW). Tail lesion severity was reduced in L1 at the end of the trial compared to the other groups (p < 0.05). Body lesion counts, however, were higher in L2 than in C (p < 0.05), resulting in a more severe overall damage classification (p < 0.01). At slaughter, no differences were observed in carcass traits or blood stress indicators, only minor differences were observed in meat quality, and no LEO residual was found in fat or lean tissues, highlighting the preserved suitability of thighs for the dry curing process. While it was not possible to conclude on the ability to improve animal welfare of vaporized LEO in this production phase, the absence of adverse effects on meat quality and the discrepancies observed regarding the body lesions in L1 and L2 make further studies on behavioral aspects and the method of administration (route, frequency) of the product desirable.

3.
ACS Nano ; 17(5): 4650-4658, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36800544

ABSTRACT

In the presence of a 4π-periodic contribution to the current phase relation, for example in topological Josephson junctions, odd Shapiro steps are expected to be missing. While missing odd Shapiro steps have been observed in several material systems and interpreted in the context of topological superconductivity, they have also been observed in topologically trivial junctions. Here, we study the evolution of such trivial missing odd Shapiro steps in Al-InAs junctions in the presence of an in-plane magnetic field Bθ. We find that the odd steps reappear at a crossover Bθ value, exhibiting an in-plane field angle anisotropy that depends on spin-orbit coupling effects. We interpret this behavior by theoretically analyzing the Andreev bound state spectrum and the transitions induced by the nonadiabatic dynamics of the junction and attribute the observed anisotropy to mode-to-mode coupling. Our results highlight the complex phenomenology of missing Shapiro steps and the underlying current phase relations in planar Josephson junctions designed to realize Majorana states.

5.
Nano Lett ; 22(15): 6173-6178, 2022 Aug 10.
Article in English | MEDLINE | ID: mdl-35867620

ABSTRACT

Indium arsenide (InAs) near surface quantum wells (QWs) are promising for the fabrication of semiconductor-superconductor heterostructures given that they allow for a strong hybridization between the two-dimensional states in the quantum well and the ones in the superconductor. In this work, we present results for InAs QWs in the quantum Hall regime placed in proximity of superconducting NbTiN. We observe a negative downstream resistance with a corresponding reduction of Hall (upstream) resistance, consistent with a very high Andreev conversion. We analyze the experimental data using the Landauer-Büttiker formalism, generalized to allow for Andreev reflection processes. We attribute the high efficiency of Andreev conversion in our devices to the large transparency of the InAs/NbTiN interface and the consequent strong hybridization of the QH edge modes with the states in the superconductor.

6.
IEEE Embed Syst Lett ; 14(1): 43-46, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35582518

ABSTRACT

As COVID-19 began to grip healthcare systems worldwide, worst-case models predicted huge demands for ventilators. The global community sprang to action, producing a large number of emergency "makeshift" ventilator designs. This brought about another problem: a gap between the quantity of new mechanical ventilators and the number of skilled physicians to operate them. New physicians could not complete training at the pace of ventilator production, which threatened to leave patients sitting untreated, next to unusable ventilators. To address this challenge, we developed a universal remote control system for makeshift ventilators that uses low-cost hardware add-on modules to connect to different ventilators, and a three-tier control architecture to interface the ventilators with telemedicine software. We demonstrate system integration with two representative ventilator designs, adding a remote control option that allows caregivers to quickly and easily monitor and control these ventilators remotely.

7.
Acta Biomed ; 92(3): e2021223, 2021 07 01.
Article in English | MEDLINE | ID: mdl-34212919

ABSTRACT

Background - Interventions for inmates with Pathological Addiction (PA) still remain a problematic issue in Italian prisons, despite a 1999 major government reform transferring PA care in prison to the National Health Service. Aim of this research was to describe the integrated intervention model implemented for prisoners with PA in the Parma Penitentiary Institutes from January 2020 to June 2020. This specific approach is based on "person-tailored" therapeutic-rehabilitation programs in line with local community PA services. Methods - All the procedures were first carefully illustrated, especially the service for newly admitted inmates and the specialized rehabilitation treatments provided. A process analysis on the first six months of clinical activity was then performed. Results - Since January 2020, 178 subjects entered the service for newly admitted inmates: 55 (30.9%) were taken in charge for a PA. Conclusions - Our results support the feasibility of an integrated intervention model for PA in Italian prisons, based on specialized psychiatric treatments planned and provided in collaboration with inmates and their community health and social services.


Subject(s)
Prisoners , Prisons , Humans , Italy , State Medicine
8.
Nat Commun ; 12(1): 78, 2021 Jan 04.
Article in English | MEDLINE | ID: mdl-33397966

ABSTRACT

Josephson junctions hosting Majorana fermions have been predicted to exhibit a 4π periodic current phase relation. One experimental consequence of this periodicity is the disappearance of odd steps in Shapiro steps experiments. Experimentally, missing odd Shapiro steps have been observed in a number of materials systems with strong spin-orbit coupling and have been interpreted in the context of topological superconductivity. Here we report on missing odd steps in topologically trivial Josephson junctions fabricated on InAs quantum wells. We ascribe our observations to the high transparency of our junctions allowing Landau-Zener transitions. The probability of these processes is shown to be independent of the drive frequency. We analyze our results using a bi-modal transparency distribution which demonstrates that only few modes carrying 4π periodic current are sufficient to describe the disappearance of odd steps. Our findings highlight the elaborate circumstances that have to be considered in the investigation of the 4π Josephson junctions in relationship to topological superconductivity.

9.
Int J Prison Health ; 17(4): 520-532, 2021 Nov 17.
Article in English | MEDLINE | ID: mdl-38902899

ABSTRACT

PURPOSE: Mental health interventions for Italian prisoners with mental disorders remain a problematic issue, despite radical changes in general psychiatric care and a 2008 major government reform transferring mental health care in prison to the National Health Service. The aim of this study is to describe the mental health intervention model implemented since January 2020 for prisoners allocated in the Parma Penitentiary Institutes (PPI). This approach is specifically based on specialized, "person-centered" and "person-tailored" therapeutic-rehabilitation plans in line with psychiatric treatments usually provided in community mental health-care centers of the Parma Department of Mental Health. DESIGN/METHODOLOGY/APPROACH: All the processes and procedures included in the PPI intervention model were first carefully illustrated, paying special attention to the service for newly admitted prisoners and each typology of specialized therapeutic-rehabilitation treatment potentially provided. Additionally, a preliminary descriptive process analysis of the first six months of clinical activity was also performed. FINDINGS: Since January 2020, 178 individuals entered the PPI service for newly admitted prisoners. In total, 83 (46.7%) of them were engaged in the services of the PPI mental health-care team (35 with pathological addiction and 48 with mental disorders): 56 prisoners were offered an integrated mental health intervention and 27 exclusively an individual psychological or psychiatric treatment. ORIGINALITY/VALUE: The results support the potential applicability of an integrated mental health intervention in prison, planning a person-tailored rehabilitation in close collaboration with the prisoners, their families and the local mental health/social services.

10.
Phys Rev Lett ; 125(3): 037001, 2020 Jul 17.
Article in English | MEDLINE | ID: mdl-32745388

ABSTRACT

Topological insulators, having intrinsic or proximity-coupled s-wave superconductivity, host Majorana zero modes (MZMs) at the ends of vortex lines. The MZMs survive up to a critical doping of the TI at which there is a vortex phase transition that eliminates the MZMs. In this work, we show that the phenomenology in higher-order topological insulators (HOTIs) can be qualitatively distinct. In particular, we find two distinct features. (i) We find that vortices placed on the gapped (side) surfaces of the HOTI, exhibit a pair of phase transitions as a function of doping. The first transition is a surface phase transition after which MZMs appear. The second transition is the well-known vortex phase transition. We find that the surface transition appears because of the competition between the superconducting gap and the local T-breaking gap on the surface. (ii) We present numerical evidence that shows strong variation of the critical doping for the vortex phase transition as the center of the vortex is moved toward or away from the hinges of the sample. We believe our work provides new phenomenology that can help identify HOTIs, as well as illustrating a promising platform for the realization of MZMs.

11.
Nat Commun ; 11(1): 212, 2020 Jan 10.
Article in English | MEDLINE | ID: mdl-31924783

ABSTRACT

In a standard Josephson junction the current is zero when the phase difference between superconducting leads is zero. This condition is protected by parity and time-reversal symmetries. However, the combined presence of spin-orbit coupling and magnetic field breaks these symmetries and can lead to a finite supercurrent even when the phase difference is zero. This is the so called anomalous Josephson effect-the hallmark effect of superconducting spintronics-which can be characterized by the corresponding anomalous phase shift. Here we report the observation of a tunable anomalous Josephson effect in InAs/Al Josephson junctions measured via a superconducting quantum interference device. By gate controlling the density of InAs, we are able to tune the spin-orbit coupling in the Josephson junction. This gives us the ability to tune the anomalous phase, and opens new opportunities for superconducting spintronics, and new possibilities for realizing and characterizing topological superconductivity.

12.
Phys Rev Lett ; 123(23): 237002, 2019 Dec 06.
Article in English | MEDLINE | ID: mdl-31868504

ABSTRACT

By tuning the angle between graphene layers to specific "magic angles" the lowest energy bands of twisted bilayer graphene (TBLG) can be made flat. The flat nature of the bands favors the formation of collective ground states and, in particular, TBLG has been shown to support superconductivity. When the energy bands participating in the superconductivity are well isolated, the superfluid weight scales inversely with the effective mass of such bands. For flat band systems one would therefore conclude that even if superconducting pairing is present, most of the signatures of the superconducting state should be absent. This conclusion is at odds with the experimental observations for TBLG. We calculate the superfluid weight for TBLG taking into account both the conventional contribution and the contribution arising from the quantum geometry of the bands. We find that both contributions are larger than one would expect treating the bands as well isolated, that at the magic angle the geometric contribution is larger than the conventional one, and that for small deviations away from the magic angle the conventional contribution is larger than the geometric one. Our results show that, despite the flatness of the bands the superfluid weight in TBLG is finite and consistent with experimental observations. We also show how the superfluid weight can be tuned by varying the chemical potential and the twist angle opening the possibility to tune the nature of the superconducting transition between the standard BCS transition and the Berezinskii-Kosterlitz-Thouless transition.

13.
Nano Lett ; 19(8): 5754-5761, 2019 08 14.
Article in English | MEDLINE | ID: mdl-31348861

ABSTRACT

The relationship between composition and plasmonic properties in noble metal nanoalloys is still largely unexplored. Yet, nanoalloys of noble metals, such as gold, with transition elements, such as iron, have unique properties and a number of potential applications, ranging from nanomedicine to magneto-plasmonics and plasmon-enhanced catalysis. Here, we investigate the localized surface plasmon resonance at the level of the single Au-Fe nanoparticle by applying a strategy that combines experimental measurements using near field electron energy loss spectroscopy with theoretical studies via a full wave numerical analysis and density functional theory calculations of electronic structure. We show that, as the iron fraction increases, the plasmon resonance is blue-shifted and significantly damped, as a consequence of the changes in the electronic band structure of the alloy. This allows the identification of three relevant phenomena to be considered in the design and realization of any plasmonic nanoalloy, specifically: the appearance of new states around the Fermi level; the change in the free electron density of the metal; and the blue shift of interband transitions. Overall, this study provides new opportunities for the control of the optical response in Au-Fe and other plasmonic nanoalloys, which are useful for the realization of magneto-plasmonic devices for molecular sensing, thermo-plasmonics, bioimaging, photocatalysis, and the amplification of spectroscopic signals by local field enhancement.

14.
Proc Natl Acad Sci U S A ; 113(24): 6623-8, 2016 06 14.
Article in English | MEDLINE | ID: mdl-27302949

ABSTRACT

One-atom-thick crystalline layers and their vertical heterostructures carry the promise of designer electronic materials that are unattainable by standard growth techniques. To realize their potential it is necessary to isolate them from environmental disturbances, in particular those introduced by the substrate. However, finding and characterizing suitable substrates, and minimizing the random potential fluctuations they introduce, has been a persistent challenge in this emerging field. Here we show that Landau-level (LL) spectroscopy offers the unique capability to quantify both the reduction of the quasiparticles' lifetime and the long-range inhomogeneity due to random potential fluctuations. Harnessing this technique together with direct scanning tunneling microscopy and numerical simulations we demonstrate that the insertion of a graphene buffer layer with a large twist angle is a very effective method to shield a 2D system from substrate interference that has the additional desirable property of preserving the electronic structure of the system under study. We further show that owing to its remarkable nonlinear screening capability a single graphene buffer layer provides better shielding than either increasing the distance to the substrate or doubling the carrier density and reduces the amplitude of the potential fluctuations in graphene to values even lower than the ones in AB-stacked bilayer graphene.

15.
Australas J Dermatol ; 56(1): 47-8, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25123581

ABSTRACT

Two cases of pseudoporphyria are described in which the clinical features of porphyria cutanea tarda occurred in the absence of abnormalities in porphyrin metabolism. Both patients presented with skin fragility and bullae on the dorsal aspect of the hands. The patients consumed a commercial liquid chlorophyll drink in which we detected fluorescent compounds with characteristics typical of previously described chlorophyll derived photosensitisers.


Subject(s)
Chlorophyll/adverse effects , Dietary Supplements/adverse effects , Hand Dermatoses/chemically induced , Hand Dermatoses/diagnosis , Porphyria Cutanea Tarda/diagnosis , Adult , Diagnosis, Differential , Female , Hand Dermatoses/metabolism , Humans , Porphyrins/blood , Porphyrins/urine
16.
Clin Gastroenterol Hepatol ; 12(1): 101-108.e4, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23906872

ABSTRACT

BACKGROUND & AIMS: Serum levels of ferritin are commonly measured to assess iron stores but are affected by factors such as obesity and chronic disease. Published reference ranges have not changed in decades, and the number of patients whose levels exceed the upper limits has been increasing. As a result, more patients are evaluated for iron overload. METHODS: We compared serum levels of ferritin in 1188 Australian adults who participated in the 2005 Busselton Population Survey with levels from the 1995 survey. Parametric regression was used to assess the effects of body weight and biochemical parameters on serum level of ferritin to derive contemporary population-appropriate reference ranges. RESULTS: In 2005, age-adjusted levels of ferritin were 21% higher in men (P < .0001) and 10% higher in women (P = .01) than in 1995; 31% of men exceeded levels of 300 µg/L, compared with 23% in 1995. Body mass index (BMI) ≥25 kg/m(2) was associated with higher levels of ferritin in men ≥35 years old and in postmenopausal women (P ≤ .002). Serum level of γ-glutamyltransferase (GGT) correlated with serum level of ferritin (P < .0001). In men, the estimated 95th percentiles ranged from 353 to 495 µg/L (<35 years), from 350 to 511 µg/L (≥35 years, BMI <25 kg/m(2)), and from 413 to 696 µg/L (≥35 years, BMI ≥25 kg/m(2)) when GGT levels were 10-75 IU/L. In women, the 95th percentiles ranged from 106 to 235 µg/L (premenopausal), from 222 to 323 µg/L (postmenopausal, BMI <25 kg/m(2)), and from 249 to 422 µg/L (postmenopausal, BMI ≥25 kg/m(2)) when GGT levels were 8-45 IU/L. CONCLUSION: Serum levels of ferritin increased significantly between 1995 and 2005. Reference ranges that accommodate demographic and biomedical variations will assist clinicians in identifying individuals who require further evaluation for iron overload.


Subject(s)
Ferritins/blood , Adult , Aged , Australia , Female , Humans , Male , Middle Aged , Reference Values , Serum/chemistry , Young Adult
17.
Liver Int ; 34(5): 720-7, 2014 May.
Article in English | MEDLINE | ID: mdl-24034439

ABSTRACT

BACKGROUND & AIMS: Liver fibrosis is prognostic of outcomes among patients with chronic hepatitis C (CHC). We evaluated the accuracy of non-invasive markers and liver biopsy in predicting morbidity and mortality in CHC patients. METHODS: Compensated CHC patients were evaluated over a 10-year period. Non-invasive markers including Hepascore, FIB-4, APRI and liver biopsy results were retrospectively collated. Follow-up morbidity and mortality data were obtained from the Western Australian Data Linkage System. The prognostic significance of baseline non-invasive markers and biopsy were assessed using Kaplan-Meier analysis. RESULTS: A total of 406 subjects (64% male, mean age 48 ± 11 years) were followed up for 2385 person-years, during which there were 22 (5.4%) deaths including 14 (3.4%) who died from liver disease or required liver transplantation. Sixteen (3.9%) subjects developed liver decompensation. Hepascore and liver biopsy (P < 0.005) but not APRI or FIB-4 were predictive of overall and liver-related mortality as well as liver decompensation. A Hepascore>0.5 was associated with increased overall mortality [Hazard Ratio (95%CI) 6.7 (2.6-17), P < 0.001], liver-related mortality [32.8 (4.3-250), P = 0.001] and risk of future decompensation [11.8 (3.3-41), P < 0.001], whereas a Hepascore ≤0.5 was associated with a 99% probability of not dying from liver-related causes over 10 years. Hepascore had comparable accuracy with liver biopsy in predicting liver-related mortality with AUROC of 0.86 (95%CI 0.80-0.90) and 0.87 (0.79-0.96), respectively. CONCLUSION: Hepascore is predictive of overall and liver-related mortality and morbidity in CHC patients with comparable accuracy to liver biopsy. Hepascore may be a useful prognostic marker in clinical practice.


Subject(s)
Biomarkers/blood , Hepatitis C, Chronic/blood , Liver Cirrhosis/blood , Liver/pathology , Adult , Biopsy , Carcinoma, Hepatocellular/etiology , Cohort Studies , Female , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/mortality , Hepatitis C, Chronic/pathology , Humans , Liver Cirrhosis/mortality , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Liver Neoplasms/etiology , Male , Middle Aged , Predictive Value of Tests , Western Australia/epidemiology
18.
J Cutan Pathol ; 40(11): 966-71, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24102632

ABSTRACT

A 31-year old man presented with swelling and purpura of the dorsum of the hands following sun exposure. There was a preceding lifelong history of photosensitivity, but this episode, which occurred after the recent commencement of oral iron therapy, and after recent alcohol ingestion, was much more severe than any preceding episode. Skin biopsy performed 48 h after the onset of symptoms showed features consistent with the early stages of leukocytoclastic vasculitis. Direct immunofluorescence showed homogeneous thick staining of the vessel walls with IgG, IgM and IgA, together with abundant perivascular fibrinogen. A subsequent periodic acid-Schiff (PAS) stain on the skin biopsy revealed thickening of the walls of dermal vessels, which was not discernible in routinely stained (hematoxylin/eosin) sections. The diagnosis of erythropoietic protoporphyria (EPP) was confirmed by significantly elevated erythrocyte protoporphyrin levels and positive plasma fluorimetry. The diagnosis of porphyria may have been missed by routine skin microscopy if not for the additional information provided by clinical history, direct immunofluorescence and PAS stain. The pathogenesis and histopathology of acute and chronic vascular changes in EPP are reviewed.


Subject(s)
Protoporphyria, Erythropoietic/complications , Protoporphyria, Erythropoietic/pathology , Vasculitis, Leukocytoclastic, Cutaneous/complications , Vasculitis, Leukocytoclastic, Cutaneous/pathology , Adult , Alcohol Drinking , Fluorescent Antibody Technique , Humans , Iron/therapeutic use , Male , Photosensitivity Disorders/complications , Photosensitivity Disorders/pathology
19.
Liver Int ; 33(8): 1249-56, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23617278

ABSTRACT

BACKGROUND: Collagen proportional area (CPA) determined by quantitative digital image analysis better quantifies liver fibrosis than histological stage; however, its clinical use has been limited by non-standardized methods. AIM: This study aimed to compare CPA obtained using different staining methods, magnifications and biopsy sizes. METHODS: Two hundred and forty-nine patients with chronic hepatitis C who had a liver biopsy and serum fibrosis markers performed were included. CPA was measured either using a sirius red (CPAs) or a trichrome (CPAt) stain. RESULTS: CPAs measured at 20× and 40× magnifications generated similar outcomes with interclass correlation (ICC) coefficient of 0.98. Compared with trichrome, sirius red staining had much less variation with an ICC coefficient of 0.99 for slides stained in the same batch and 0.92 in different batches. Mean CPAs was higher than mean CPAt by 3.53%, P < 0.001. Morphological analysis found that sirius red detected delicate fibrous septa and spurs better than trichrome. Both CPAs and CPAt correlated well with Metavir stage, whereas CPAs had better ability to detect cirrhosis with the area under ROC curve of 0.95. Overall CPA had superior correlation with serum markers of fibrosis in Metavir F2-F4 than that in F0-F1 and CPAs correlated better with serum fibrosis markers than CPAt in Metavir F0-F1. Multivairate analysis found that HA, α2-macroglobulin, platelet count and albumin were independently correlated with CPAs and only HA was independently correlated with CPAt. CONCLUSIONS: Sirius red staining for CPA determination was more accurate and reliable for quantifying hepatic collagen compared with trichrome staining.


Subject(s)
Azo Compounds , Collagen/analysis , Coloring Agents , Eosine Yellowish-(YS) , Liver Cirrhosis/diagnosis , Liver/chemistry , Methyl Green , Staining and Labeling/methods , Adult , Biomarkers/blood , Biopsy , Female , Hepatitis C, Chronic/complications , Humans , Image Interpretation, Computer-Assisted , Liver/pathology , Liver/virology , Liver Cirrhosis/blood , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Male , Multivariate Analysis , Predictive Value of Tests , Reproducibility of Results , Retrospective Studies , Severity of Illness Index
20.
World J Gastroenterol ; 19(5): 673-81, 2013 Feb 07.
Article in English | MEDLINE | ID: mdl-23429835

ABSTRACT

AIM: To evaluate whether desferrioxamine decreases ischemia and perfusion injury aggravated by cold storage (CS) in a rat liver perfusion model. METHODS: Isolated rat livers were kept in CS in University of Wisconsin Solution for 20 h at 4 °C, then exposed to 25 min of warm ischemia (WI) at 37 °C followed by 2 h of warm perfusion (WP) at 37 °C with oxygenated (95% oxygen and 5% carbon dioxide) Krebs-Henseleit buffer. Desferrioxamine (DFO), an iron chelator, was added at different stages of storage, ischemia and perfusion: in CS only, in WI only, in WP only, in WI and perfusion, or in all stages. Effluent samples were collected after CS and after WI. Perfusate samples and bile were collected every 30 min (0, 0.5, 1, 1.5 and 2 h) during liver perfusion. Cellular injury was assessed by the determination of lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) in the effluent and perfusate samples. Total iron was analysed in the perfusate samples. After WP, the liver was collected for the determination of liver swelling (wet to dry ratio) and liver morphological examination (hematoxylin and eosin staining). RESULTS: Increased CS time caused increased liver dysfunction during WP. After 2 h of WP, liver injury was indicated by increased release of AST (0.5 h CS: 9.4 ± 2.2 U/g liver vs 20 h CS: 45.9 ± 10.8 U/g liver, P < 0.05) and LDH (0.5 h CS: 59 ± 14 U/g liver vs 20 h CS: 297 ± 71 U/g liver, P < 0.05). There was an associated increase in iron release into the perfusate (0.5 h CS: 0.11 ± 0.03 µmoL/g liver vs 20 h CS: 0.58 ± 0.10 µmoL/g liver, P < 0.05) and reduction in bile flow (0.5 h CS: 194 ± 12 µL/g vs 20 h CS: 71 ± 8 µL/g liver, P < 0.05). When DFO was added during WI and WP following 20 h of CS, release of iron into the perfusate was decreased (DFO absent 0.58 ± 0.10 µmoL/g liver vs DFO present 0.31 ± 0.06 µmoL/g liver, P < 0.05), and liver function substantially improved with decreased release of AST (DFO absent 45.9 ± 10.8 U/g liver vs DFO present 8.1 ± 0.9 U/g liver, P < 0.05) and LDH (DFO absent 297 ± 71 U/g liver vs DFO present 56 ± 7 U/g liver, P < 0.05), and increased bile flow (DFO absent 71 ± 8 µL/g liver vs DFO present 237 ± 36 µL/g liver, P < 0.05). DFO was also shown to improve liver morphology after WP. Cellular injury (the release of LDH and AST) was significantly reduced with the addition of DFO in CS medium but to a lesser extent compared to the addition of DFO in WP or WI and perfusion. There was no effect on liver swelling or bile flow when DFO was only added to the CS medium. CONCLUSION: DFO added during WI and perfusion decreased liver perfusion injury aggravated by extended CS.


Subject(s)
Deferoxamine/pharmacology , Liver Transplantation/methods , Liver/drug effects , Liver/surgery , Perfusion/methods , Siderophores/pharmacology , Warm Ischemia , Animals , Aspartate Aminotransferases/metabolism , Biomarkers/metabolism , Cold Ischemia/adverse effects , Cytoprotection , Hepatectomy , L-Lactate Dehydrogenase/metabolism , Liver/enzymology , Liver/pathology , Liver Transplantation/adverse effects , Male , Perfusion/adverse effects , Rats , Time Factors
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