Prophylactic Use of Laser Light and Methylene Blue on Ischemia and Liver Reperfusion Injury.

OBJECTIVE: This study aimed to evaluate the effect of hepatic preconditioning with laser light in the presence of methylene blue (MB) in the liver ischemia-reperfusion injury process. METHOD: Forty male Wistar rats were divided into 8 experimental groups (n = 5). Saline (.5 mL) or MB (15 mg/kg) was injected intravenously (inferior vena cava). After 2 minutes, 660 nm laser light was applied at a dose of 112.5 DE. Fifteen minutes after the application of saline or MB, 1 hour partial ischemia followed by 15 minutes of reperfusion was applied when the rats were sacrificed. The mitochondrial function parameters (O2 consumption rates in states 3 and 4 and the respiratory control ratio), osmotic swelling, and determination of malondialdehyde were evaluated. Hepatic function was studied using the serum determination of the alanine aminotransferase and aspartate aminotransferase enzymes. RESULTS AND CONCLUSIONS: MB therapy alone showed the capacity of preserving the rate of oxygen consumption in the mitochondrial respiratory state of the group submitted to ischemia compared to the sham group. However, when combined with low-intensity laser therapy, it failed to replicate the relevant protective effects in relation to oxidative phosphorylation or the mitochondrial membrane ischemia/reperfusion injury. Whether or not MB was combined with laser treatment, it was shown to be efficient in reducing oxidative stress. In relation to alanine aminotransferase enzymes, whether or not laser treatment was combined with MB had a protective effect on the hepatic lesion, whereas in relation to aspartate aminotransferase enzymes only laser treatment was able to provide this protection.

Effect of Hepatic Preconditioning with the Use of Methylene Blue on the Liver of Wistar Rats Submitted to Ischemia and Reperfusion.

BACKGROUND: The liver may be injured in situations where it is submitted to ischemia, such as partial hepatectomy and liver transplantation. In all cases, ischemia is followed by reperfusion and, although it is essential for the reestablishment of tissue function, reperfusion may cause greater damage than ischemia, an injury characterized as ischemia-reperfusion (I/R) damage. The aim of this work was to analyze the effect of ischemic preconditioning with the use of methylene blue (MB; 15 mg/kg) 5 or 15 minutes before I/R (IRMB5' and IRMB15', respectively) on the hepatic injury occurring after I/R. METHODS: Twenty-eight male Wistar rats were used, and liver samples submitted to partial ischemia (IR) or not (NI) were obtained from the same animal. The samples were divided into 7 groups. Data were analyzed statistically by means of the nonparametric Mann-Whitney test and Wilcoxon Matched test, with the level of significance set at 5% (P < .05). RESULTS: The rate of oxygen consumption by state 3 mitochondria was inhibited in all ischemic groups compared with the sham group (SH vs IR: P = .0052; SH vs IRMB5': P = .0006; SH vs IRMB15': P = .0048), which did not occur in the nonischemic contralateral portion of the same liver (SH vs NI: P = .7652; SH vs NIMB5': P = .059; SH vs NIMB15': P = .3153). The inhibition of the rate of oxygen consumption by state 3 mitochondria was maintained in the presence of MB (IR vs IRMB5': P = .4563; IR vs IRMB15': P = .9021). The respiratory control ratio was reduced in all ischemic groups compared with the sham group, owing to the inhibition of oxygen consumption in state 3 (SH vs IR: P = .0151; SH vs IRMB5': P = .005; SH vs IRMB15': P = .0007). CONCLUSIONS: Methylene blue had no effect on the mitochondrial respiratory parameters studied, but was able to reduce lipid peroxidation, preventing the production of reactive oxygen species (SH vs IRMB15': P = .0210).

Anxiety and Stress Levels on Liver Transplantation Candidates.

The objective of the present study was to determine the anxiety and stress levels of liver transplant candidates during the preoperative period. A cross-sectional, prospective study was conducted on 52 liver transplantation candidates seen at a specialized public hospital outpatient clinic in the interior of the state of São Paulo, Brazil. Data were collected from November 2014 to April 2015 using a self-applicable questionnaire for the assessment of anxiety (State-Trait Anxiety Inventory, short version) and stress (Perceived Stress Scale), in addition to sociodemographic and clinic characterization. The mean (±SD) anxiety level detected was 23.06 ± 5.51 points, with 1.92% of the subjects showing minimum levels (0 to 12 points), 59.62% a medium level (12 to 24 points), 36.54% a moderate level (24 to 36 points), and 1.92% a severe level (36 to 48 points) of anxiety. The mean level on the stress scale was 12.10 ± 5.62 points, with 7.69% of the subjects showing high stress levels. When individuals with good and poor stress levels were compared, a significant difference was observed between them (P = .0004). The Spearman correlation test showed that the higher the stress, the higher the levels of anxiety (r = 0.4258), P < .0001. The present study contributes to the analysis of the mental health of liver transplantation candidates in view of the need for interventions for the improvement of anxiety and stress levels since the waiting period for the organ generates emotional changes that can affect the quality of life of the patient and the success of this complex therapeutic modality.

Sleep Quality Assessment and Daytime Sleepiness of Liver Transplantation Candidates.

OBJECTIVE: The goal of this study was to evaluate the sleep quality and daytime sleepiness of patients eligible for liver transplants. METHODS: A cross-sectional prospective study was conducted on liver transplant candidates from a transplant center in the interior of São Paulo State. The Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale questionnaires were applied to obtain demographic and clinical characteristics and to assess sleep quality and daytime sleepiness. RESULTS: The mean (±SD) score on the Epworth Sleepiness Scale of the 45 liver transplantation candidates was 7.00 ± 2.83 points, with 28.89% having scores >10 points, indicating excessive daytime sleepiness. The mean score on the Pittsburgh Sleep Quality Index was 6.64 ± 4.95 points, with 60% of the subjects showing impaired sleep quality, with scores >5 points. The average sleep duration was 07:16 h. Regarding sleep quality self-classification, 31.11% reported poor or very poor quality. It is noteworthy that 73.33% of patients had to go to the bathroom, 53.33% woke up in the middle of the night, and 40.00% reported pain related to sleeping difficulties. Comparison of subjects with good and poor sleep quality revealed a significant difference in time to sleep (P = .0002), sleep hours (P = .0003), and sleep quality self-classification (P = .000072). CONCLUSION: Liver transplant candidates have a compromised quality of sleep and excessive daytime sleepiness. In clinical practice, we recommend the evaluation and implementation of interventions aimed at improving the sleep and wakefulness cycle, contributing to a better quality of life.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia.

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

Relevance of anxiety and stress levels on sleep quality after liver transplantation.

The goal of this study was to assess the effects of anxiety and stress on sleep quality in liver transplantation recipients. A prospective cross-sectional study was performed including 45 recipients enrolled at a liver transplantation program at Ribeirão Preto, State of São Paulo, Brazil. Anxiety and stress were evaluated by using a reduced version of the State-Trait Anxiety Inventory and the Perceived Stress Scale, respectively. Sleep quality and excessive daytime sleepiness were evaluated by using the Brazilian Portuguese versions of the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Thirty-two (71.11%) recipients presented with compromised sleep quality and 5 (11.11%) presented with excessive daytime sleepiness. Recipients with bad sleep quality had anxiety (mean, 26.91 points) and stress (mean, 17.88 points) levels that were higher than the levels of patients with normal sleep quality patterns, with anxiety levels presenting with statistically significant differences (P = .0420). Patients with above-average stress levels also had increased anxiety (mean, 28 points) and compromised sleep quality (mean, 7.03 points). In conclusion, a liver transplantation recipient who experiences bad sleep quality also has higher levels of anxiety and stress, suggesting a relationship between the sleep-wakefulness cycle and anxiety/stress. Planning strategies aimed at reducing such emotional shifts among recipients is of paramount importance. Therefore, new strategies focusing on improving the sleep pattern of patients are necessary because unhealthy sleep behavior may impair postoperative recovery.

Ex situ regeneration of liver remnants hypothermically preserved for 24 hours.

INTRODUCTION: After partial hepatectomy (PH), the liver remnant (LR) shows a regenerative response, always keeping a percent relationship with the host. This process has been well described in the literature, but several aspects still need to be understood. There are no studies on hepatic LR regeneration during hypothermic preservation. Thus, the objective of the present study was to analyze LR regeneration after PH under conditions of hypothermal preservation. MATERIALS AND METHODS: Twenty adult Wistar rats were divided into 4 experimental groups: PHS (70% PH); PHP (70% PH of an organ perfused and preserved for 24 hours); PWL (perfused whole liver preserved for 24 hours); and NPWL (nonperfused whole liver). The liver was perfused with 250 mL Celsior solution with a catheter connected to a 1.30-cm-high liquid column. Hepatic tissue samples were submitted to immunohistochemical analysis for the evaluation of protein Ki67 expression, related to the mechanism of cell proliferation, to analysis of micro-RNA expression (miR-21 and miR-16) by real-time polymerase chain reaction, and to analysis of mitochondrial function. Nonparametric statistical analysis was used (P < .05). RESULTS: Ki67 analysis revealed that the PHP group showed 17.41% cell proliferation in LR (P < .01) compared to PHS (42.22%), PWL (11.43%), and NPWL (11.98%). miR-16 expression (proapoptotic) was found to be higher in the NPWL group compared to all others (PHS, PHP, and PWL), with a statistically significant difference between the NPWL group and the PHS and PHP groups. CONCLUSION: The animals submitted to PHS and PHP presenting greater Ki67 expression showed low miR-16 expression, indicating a low apoptotic index. In summary, the LR showed ex situ regeneration even under hypothermal conditions. There are no similar data in the literature surveyed.

A new formula as a predictive score of post-liver transplantation outcome: postoperative MELD-lactate.

INTRODUCTION: Liver transplantation (OLT) involves a 5% to 10% 30-day mortality rate. Multiple scores have been used as predictors of early postoperative mortality, such as the original Model for End-stage Liver Disease (MELD) and MELD sodium. Investigations have been conducted over the last 5 years to find new predictors of early post-OLT mortality. OBJECTIVE: The aim of this study was to develop a new mathematical model to predict the individual chance of 30-day mortality after OLT. METHODS: The study was conducted on 58 patients submitted to OLT at the University Hospital, between October 2008 and March 2012. The 29 latest survivor and 29 latest nonsurvivor cases were selected. Arterial blood sodium, lactate, international normalized ratio, total bilirubin, and creatinine values were determined 1 hour after the end of surgery. The MELD original equation, MELD sodium, and new MELD lactate were also elaborated. The results were analyzed by the Mann-Whitney and Wilcoxon tests. The level of significance was set at .05. RESULTS: The new formula elaborated was as follows: MELD lactate = 5.68 × loge (lactate) + 0.64 × (Original MELD) + 2.68. The MELD lactate values were significantly higher than the MELD sodium and original MELD values (P < .05). The area under the receiver operating characteristic curve of MELD lactate in predicting the outcome of patients submitted to OLT was 0.80, as opposed to 0.71 for the original MELD and 0.72 for MELD sodium (P < .05). CONCLUSION: The postoperative MELD lactate score proved to be more specific and sensitive than the original MELD and MELD sodium as a predictive model of the outcome of patients submitted to OLT.

Evaluation of oxidative stress in the late postoperative stage of liver transplantation.

INTRODUCTION: Liver transplant recipients are at an increased oxidative stress risk due to pre-existing hepatic impairment, ischemia-reperfusion injury, immunosuppression, and functional graft rejection. This study compared the oxidative status of healthy control subjects, patients with liver cirrhosis on the list for transplantation, and subjects already transplanted for at least 12 months. PATIENTS AND METHODS: Sixty adult male patients, aged between 27 and 67 years, were subdivided into 3 groups: a control group (15 healthy volunteers), a cirrhosis group (15 volunteers), and a transplant group (30 volunteers). Oxidative stress was evaluated by activity of reduced glutathione, malondialdehyde, and vitamin E. RESULTS: There was a significant difference (P < .01) in the plasma concentration of reduced glutathione in the 3 groups, with the lowest values observed in the transplanted group. The malondialdehyde values differed significantly (P < .01) among the 3 groups, with the transplanted group again having the lowest concentrations. The lowest concentrations of vitamin E were observed in patients with cirrhosis compared with control subjects, and there was a significant correlation (P < .05) among the 3 groups. No correlations were found between reduced glutathione and vitamin E or between vitamin E and malondialdehyde. However, there were strong correlations between plasma malondialdehyde and reduced glutathione in the 3 groups: control group, r = 0.9972 and P < .0001; cirrhotic group, r = 0.9765 and P < .0001; and transplanted group, r = 0.8981 and P < .0001. CONCLUSIONS: In the late postoperative stage of liver transplantation, oxidative stress persists but in attenuated form.

Should preconditioning hyperbaric oxygenation protect the liver against ischemia-reperfusion injury? An experimental study in a rat model.

OBJECTIVES: We designed studies to test the hypotheses that hyperbaric oxygen (HBO) therapy should protect liver against subsequent ischemia/reperfusion (I/R) injury are scarce and controversial. The purpose of this study was to clarify some questions about the association of HBO with the processes of liver I/R. METHODS: We divided Wistar rats into 5 groups: (1) SHAM operation, (2) I/R, rats submitted to total pedicle ischemia for 30 minutes followed by 5 minutes of reperfusion; (3) HBO60I/R and (4) HBO120I/R, rats respectively submitted to 60 and 120 minutes of HBO therapy at 2 absolute atmospheres and immediately after submitted to the experimental protocol of I/R; (5) HBO120, rats submitted to 120 minutes of HBO therapy at 2 absolute atmospheres and then immediately after humanely killed. The experimental protocol included (1) serum levels of aspartate and alanine aminotransferase; (2) mitochondrial function; (3) tissue malondialdehyde (MDA); and (4) plasma nitrite/nitrate. Data were analyzed using the Mann-Whitney test and were considered significant P < 5%. RESULTS: The processes of liver ischemia/reperfusion caused tissue injury with hepatic mitochondrial functional impairment. A single exposure to 120 minutes of HBO caused an increase of tissue MDA. The time of HBO exposure as preconditioning before hepatic I/R is critical in the prevalence of beneficial or deleterious effects. Sixty minutes of hyperoxic preconditioning before liver I/R presents systemic benefits, but no significant tissue preservation. One hundred twenty minutes of hyperoxic preconditioning tissue liver benefits predominate compared with systemic benefits. CONCLUSIONS: The HBO preconditioning therapeutic benefits to liver I/R injury are time dependent, suggesting a therapeutic window that needs to be clearly defined in future studies.

The 14bp-deletion allele in the HLA-G gene confers susceptibility to the development of hepatocellular carcinoma in the Brazilian population.

Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule involved in tumor escape mechanisms. Considering that the HLA-G 14bp insertion/deletion polymorphism is located at the 3' untranslated region (3'UTR) in exon 8, and since it has been associated with the magnitude of HLA-G production, we studied the association of 14bp insertion/deletion polymorphism with the risk of developing hepatocellular carcinoma (HCC). A total of 109 HCC patients followed at the University Hospital, Faculty of Medicine of Ribeirão Preto, São Paulo, Brazil, and 202 healthy controls from the same geographic area were genotyped for the 14bp insertion/deletion polymorphism using polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis. Compared to controls, the frequency of the 14bp deletion allele was overrepresented in HCC patients (65% versus 56%, respectively, P = 0.0326). The 14bp deletion conferred an odds ratio (OR) of 1.46 [95% confidence interval (CI): 1.04-2.05]. Similarly, the deletion/deletion genotype was marginally overrepresented in HCC patients (45% versus 35% in controls, P = 0.0871), conferring an OR of 1.54 (95% CI: 0.96-2.48). The frequencies of the deletion/insertion or insertion/insertion genotypes observed in patients were not statistically different from those observed in controls (P > 0.05). Our results suggest that the 14bp-deletion allele in HLA-G gene is associated with HCC susceptibility in a Brazilian population.

Effect of methylene blue on the hemodynamic instability resulting from liver ischemia and reperfusion in rabbits.

The experimental investigation was performed to study the effects of methylene blue (MB) on hemodynamic, biochemical, and tissue changes among rabbits undergoing liver ischemia and reperfusion (IR). Twenty-four rabbits were randomized into 5 groups: 1, SHAM, control; 2, MB infusion bolus (3 mg/kg); 3, IR, hepatic ischemia for 60 minutes followed by 120 minutes of reperfusion; 4, MB-R, undergoing ischemia that had received an MB bolus infusion (3 mg/kg) prior to reperfusion; 5, R-MB, undergoing ischemia and MB bolus infusion after hemodynamic instability caused by reperfusion. The analysis included continuous recording of vital signs. Blood samples were collected at 0, 60, and 180 minutes of IR to determine blood gases as well as biochemical markers of liver function, nitric oxide, lipid peroxidation, and neutrophil activity. At the end of each experiment, liver tissue samples were collected for histological evaluation of parenchymae markers. Statistical analysis used two-way analysis of variance (ANOVA) tests with significance set at P<.05. Vital signs significantly improved with MB infusion, irrespective of whether it was applied before or after reperfusion. Blood gas data revealed different patterns among the SHAM, MB, IR, MB-R, and R-MB groups, without statistical significance, except for favorable lactate results in the R-MB group (P<.01), which displayed greater survival. Biochemical tests did not show significant differences among the groups, whereas histological analysis revealed favorable appearances for the MB-R and R-MB groups. The MB effect lasted long after reperfusion, suggesting that improvement in the hemodynamic parameters was not based on liver integrity, but rather was possibly related to endothelial function.

Comparison of acute physiology and chronic health evaluation II death risk, Child-Pugh, Charlson, and model for end-stage liver disease indexes to predict early mortality after liver transplantation.

OBJECTIVE: This study sought to determine which prognostic index was the most efficient to predict early (1-month) mortality of patients undergoing orthotopic liver transplantation (OLT). MATERIALS AND METHODS: This retrospective study included 63 patients including 49 males and 14 females of overall median age 51.6 ± 9.7 years who were admitted to the intensive care unit (ICU) of a tertiary hospital. The Acute Physiology and Chronic Health Evaluation II (APACHE II) death risk, Child-Pugh, Charlson, and Model for End-stage Liver Disease (MELD) indices pre-OLT and post-OLT were analyzed by generation of receiver operating characteristic (ROC) curves to determine the area under the ROC curve (AUC), as a predictive factor for each index. The level of significance was set at P < .05. RESULTS: The general 1-month posttransplantation mortality rate of OLT patients was 19% (n = 12 p). The AUC was 0.81 (confidence interval [CI] = 0.66-0.96; sensitivity = 72.5; specificity = 83.3) for APACHE II death risk; 0.74 (CI = 0.57-0.92; sensitivity = 76.5; specificity = 66.7) for MELD post-OLT; 0.70 (CI = 0.54-0.85; sensitivity = 64.7; specificity = 66.7) for Child-Pugh; 0.57 (CI = 0.36-0.78; sensitivity = 74.5; specificity = 50.0) for Charlson; and 0.50 (CI = 0.32-0.69; sensitivity = 98.0; specificity = 16.7) for MELD Pre-OLT. CONCLUSION: Among the studied indices, the APACHE II death risk scoring system was the most effective to predict early mortality after OLT.

Treatment of hepatocellular carcinoma with liver transplantation: a single-center experience from Brazil.

INTRODUCTION: Orthotopic liver transplantation (OLT) is the treatment of choice of hepatocellular carcinoma (HCC) for patients with cirrhosis, mainly those with early HCC. Herein we have present the clinical characteristics and outcomes of cirrhotic patients with HCC who underwent OLT from cadaveric donors in our institution. METHODS: From May 2001 to May 2009, we performed 121 OLT including 24 patients (19.8%) with cirrhosis and HCC within the Milan criteria. In 4 cases, HCC was an incidental finding in the explants. RESULTS: The patients' average age was 55 +/- 10 years, including 82% men. Fifty percent of patients were Child class B or C. The average Model for End Stage Liver Disease for Child A, B, and C categories were 11, 15, and 18, respectively. The HCC diagnosis was made by 2 dynamic images in 16 cases; 1 dynamic image plus alphafetoprotein >400 ng/mL in 4; and 4 by histologic confirmation. Twenty patients received a locoregional treatment before OLT: 6 percutaneous ethanol injection, 9 transarterial chemoembolization, 1 transarterial embolization, and 4 a combination of these modalities. The median follow-up after OLT was 19.7 months (range, 1-51). A vascular invasion was observed in the explant of 1 patient, who developed an HCC recurrence and succumbed at 8 months after OLT. Two further patients, without vascular invasion or satellite tumor displayed tumor recurrences at 7 and 3 months after OLT, and death at 2 and 1 month after the diagnosis. The remaining 25 patients have not shown a tumor recurrence. CONCLUSION: In the present evaluation, OLT patients with early HCC and no vascular invasion showed satisfactory results and good disease-free survival. Strictly following the Milan criteria for liver transplantation in patients with HCC greatly reduces but does not completely avoid, the chances of tumor recurrence.

Determination of threshold dose of photodynamic therapy to measure superficial necrosis.

BACKGROUND DATA: Photodynamic therapy (PDT) involves the photoinduction of cytotoxicity using a photosensitizer agent, a light source of the proper wavelength, and the presence of molecular oxygen. A model for tissue response to PDT based on the photodynamic threshold dose (D(th)) has been widely used. In this model cells exposed to doses below D(th) survive while at doses above the D(th) necrosis takes place. OBJECTIVE: This study evaluated the light D(th) values by using two different methods of determination. One model concerns the depth of necrosis and the other the width of superficial necrosis. MATERIALS AND METHODS: Using normal rat liver we investigated the depth and width of necrosis induced by PDT when a laser with a gaussian intensity profile is used. Different light doses, photosensitizers (Photogem, Photofrin, Photosan, Foscan, Photodithazine, and Radachlorin), and concentrations were employed. Each experiment was performed on five animals and the average and standard deviations were calculated. RESULTS: A simple depth and width of necrosis model analysis allows us to determine the threshold dose by measuring both depth and surface data. Comparison shows that both measurements provide the same value within the degree of experimental error. CONCLUSION: This work demonstrates that by knowing the extent of the superficial necrotic area of a target tissue irradiated by a gaussian light beam, it is possible to estimate the threshold dose. This technique may find application where the determination of D(th) must be done without cutting the tissue.

Communication between organ donor families and recipients: a definitely controversial subject.

In transplant centers, few topics are more controversial than communication between organ donor families (ODF) and recipients (RE). The Organ Procurement Organizations and transplant centers have felt obliged to protect the confidentiality and interests of ODF and RE. However, some authors have reported favorable effects of contact between ODF and RE. This study sought to investigate the current situation of the communication between ODF and RE from the viewpoint of transplanted patients (n = 50) and waiting transplant patients (n = 50) at a Brazilian University Hospital, ODF (n = 10), physicians from transplant centers (n = 50), as well as the opinion of the general population of a Brazilian city (n = 100). This work was developed as a survey whose questions related to the issue of communication between ODF and RE. The results showed that the majority of transplanted patients (82%) and patients awaiting transplant (60%) wanted to meet ODF to express their gratitude for receiving the organ. Likewise, ODF (67%) wanted to have a meeting with recipients, which allowed them to confirm the benefit of their donation. The general population was also favorable (66%) to ODF and RE communication. In contrast, the physicians (74%) were opposed to the ODF and RE contact. They affirmed that direct contact could lead to serious emotional conflicts or attempts of material involvement. One believes that decisions concerning the contact between ODF and RE would have to be determined by the involved parties. The transplant team could analyze the requests case by case, but ODF and RE must have the right to make the final decision.

Autofluorescence spectroscopy in liver transplantation: preliminary results from a pilot clinical study.

The evaluation of graft function at various stages after transplantation is relevant, particularly at the moment of organ harvest, when a decision must be made whether to use the organ. Autofluorescence spectroscopy is noninvasive technique to monitor the metabolic condition of a liver graft throughout its course, from an initial evaluation in the donor, through cold ischemia transportation, to reperfusion and reoxygenation in the recipient. Preliminary results are presented in six liver transplantations spanning the periods from liver harvest to implant. The laser-induced fluorescence spectrum at 532-nm excitation was investigated before cold perfusion (autofluorescence), during cold ischemia, at the back table procedure, as well as 5 and 60 minutes after reperfusion. The results showed that the fluorescence analysis was sensitive to changes during the transplantation procedure. Fluorescence spectroscopy potentially provides a real-time, noninvasive technique to monitor liver graft function. The information could potentially be valuable for surgical decisions and transplant success.

Liver mitochondrial function in familial amyloidotic polyneuropathy.

The objective of the present study was to analyze hepatic mitochondrial function in patients with familial amyloidotic polyneuropathy (FAP) undergoing cadaveric donor orthotopic liver transplantation. From February 2005 to May 2007, eight patients with FAP, ranging in age from 34 to 41 years and with Model for End-Stage Liver Disease scores ranging from 24 to 29. Underwent orthotopic transplantation using a liver from a deceased donor by the piggyback method. Immediately before beginning the recipient hepatectomy in a patient with FAP, a biopsy was obtained for analysis of mitochondrial function (FAP group). The control group consisted of 15 patients undergoing hepatic surgery to treat small tumors of the liver. Mitochondrial respiration was determined on the basis of oxygen consumption by energized mitochondria using a polarographic method. The membrane potential of the mitochondria was determined spectrofluorometrically. Data were analyzed statistically by the Mann-Whitney test, with the level of significance set at 5%. State 3 and 4 values, respiratory control ratio, and membrane potential were 47 +/- 8 versus 28 +/- 10 natoms O/min/mg protein (P < .05); 14 +/- 3 vs 17 +/- 7 nat.O/min/mg.prot.mit. (P > .05); 3.6 +/- .5 vs 1.7 +/- 0.7 (P < .05); and 135 +/- 5.2 vs 135 +/- 6 mV (P > .05) for control versus FAP patients, respectively, demonstrating a decreased energy status of the liver in FAP.

Evaluation of the respiratory muscle strength of cirrhotic patients: relationship with Child-Turcotte-Pugh scoring system.

Pulmonary abnormalities are observed in chronic hepatopathy. The measurement of the maximum inspiratory and expiratory pressure may evaluate lung function and the risks associated with hepatic transplantation. Thus, the present work sought to evaluate the respiratory muscle strength of 29 patients between 17 and 63 years old who were enrolled for liver transplantation. The patients were classified according to Child-Turcotte-Pugh score as A, B, or C, and also according to a physiotherapeutic evaluation, which included measurement of respiratory muscle strength by means of a digital manovacuometer, which determines the maximum inspiratory pressure (MaxIP) and the maximum expiratory pressure (MaxEP). The tests were performed with seated individuals having their nostrils obstructed by a nasal clip. The MaxIP was measured during the effort initiated in the residual volume, whereas the MaxEP was measured during the effort initiated in the total pulmonary capacity, keeping pressures stable for at least 1 second. The statistical analysis was performed through using the Mann-Whitney test with a 5% level of significance. The MaxIP values of Child A 95.5 +/- 40.507 cm H(2)O (average +/- DP) and Child B 87.2 +/- 35.02 patients were higher than those for Child C patients (34.83 +/- 3.68; P < .05). Similar results were observed for the MaxEP of Child A and B groups (116.25 +/- 31.98 and 97.28 +/- 31.08, respectively; P < .05), versus the Child C group (48.16 +/- 22.60). Between groups A and B, the MaxEP were similar (P > .05). We concluded that Child C patients display muscle weakness significantly greater than that of subjects classified as Child A or B.