Persistent lymph nodes after curative chemoradiotherapy for head and neck cancer: imaging predictors of response for decision-making.

PURPOSE: To identify response predictors in patients with head and neck squamous cell carcinoma (N + HNSCC) and persistent lymph nodes after curative chemoradiotherapy treatment (CCRT). MATERIALS AND METHODS: Consecutive patients with N + HNSCC treated with CCRT and persistent lymph nodes at first follow-up between 2015 and 2021 were identified and analyzed. Complete response was defined as the absence of lymph node metastatic involvement in patients with salvage lymphadenectomy or the absence of progression after 1 year of successive follow-ups. Tumour type and location, staging, and human papillomavirus (HPV) status were considered for analysis. The number and size of lymph nodes, type, shape, enhancement and margins on diagnostic and follow-up CT were also analyzed. RESULTS: The cohort included 46 patients with 134 pathological lymph nodes. Logistic regression models showed the following variables to be significant: performance of salvage lymphadenectomy (OR 0.094, [CI 95% 0.004-0.61], p = 0.037); the type of lymphadenopathy on diagnostic CE-CT (solid vs. cystic) (N1: OR = 4.11, [CI 95% 1.11-17.93], p = 0.042 and N3: OR 6.42, [CI 95% 1.2-42.56], p = 0.036); the change of shape (round to oval) on the follow-up CE-CT (OR 9.76, [CI 95% 1.79-8.57], p = 0.016) and the time in days between CCRT and the first follow-up CE-CT (OR 1.06, [CI 95% 1.004-1.13], p = 0.048). CONCLUSIONS: In our experience, the presence of solid lymph nodes on pre-treatment CT and the change in shape from round to oval on post-treatment CT are predictors of response to treatment in patients with N + HNSCC persistent lymph nodes after CCRT. Increasing the temporal interval between treatment and follow-up CT should be considered to avoid unnecessary nodal dissections.

Sinonasal mucosal melanomas: defining profiles for better survival outcomes.

BACKGROUND: Sinonasal mucosal melanoma is an aggressive malignancy with a 5-year survival rate ranging from 20% to 39%. Despite the evolving surgical and radiotherapy techniques, and introduction of immune-checkpoint inhibitor therapy, overall survival rates remain poor. METHODOLOGY: A retrospective cohort study was conducted at the Hospital Clinic de Barcelona and the Hospital de la Santa Creu i Sant Pau between 1984 and 2020; primary outcome measures were 3 and 5-year melanoma-specific survival (MSS). Kaplan-Meier survival analysis and Cox proportional hazards model were performed to identify predictors of survival. RESULTS: Fifty patients were included, the mean age was 70.4, MSS at 3 and 5 years was 51.2%, and 29.5%, respectively. The median follow-up was 39.6 months during which 46% presented locoregional recurrence and 36%, metastasis. The univariate and multivariate analyses found as survival predictors the N category, the treatment received, the surgical margins and the mitotic index. CONCLUSIONS: We found an overall 5-year MSS of 29.5%. Those patients with intention-to-cure (stages III and IVa) treated by surgery that were N0 at diagnosis, with < 10 mitoses per HPF showed a 5-year MSS rate of 74.1%. More studies will be needed to adequately define the patients' profiles that will benefit from a better survival outcome.

Breaking Down Barriers: Easter Island's First Telestroke Thrombolysis Experience and Case Report.

Easter Island (Rapa Nui), Chile, is remote, located in the Polynesian Triangle in Oceania. The closest continental point is Chile, 3,512 km east. It has a population of 7,750 inhabitants, who are Chilean citizens, and receives more than 60,000 tourists a year. For this entire population, there is a medium complexity hospital without a neurology specialist. In 2019, local professionals were trained in a Telestroke program with remote clinical support conducted by neurologists located on mainland Chile. We present a 50-year-old native male, with unknown medical history, who suddenly presented right-half-body weakness and aphasia. He was evaluated via Telestroke consultation, and thrombolysis with tenecteplase was indicated. The patient improved rapidly and 45 min later the NIHSS score was 0 points. To our knowledge, this is the first reported case of Telestroke treatment in such a remote area, highlighting the importance of telemedicine to overcome geographical and technological stroke care barriers and to improve patients' outcome, no matter where they live.

Life cycle assessment, C footprint and carbon balance of virgin olive oils production from traditional and intensive olive groves in southern Spain.

Olive oil production shapes the socio-economic and environmental life of many areas of the Mediterranean basin, especially southern Spain, the highest olive oil-producing region worldwide. Olive grove cultivation is tending to intensify from traditional low-density to intensive and high-density cropping systems, which might result in higher environmental impacts. The aim of this study is to estimate the environmental impacts, carbon (C) footprint and carbon balance of producing virgin origin olive oil in Spain from four traditional rainfed, four irrigated, and three intensive olive farms, including the processing phase. Environmental impacts of producing 1 kg of unpacked virgin olive oil at the farm and industrial phases were quantified with the Life Cycle Assessment (LCA) tool and a "cradle-to-gate" approach using data from surveys at these farms and 12 olive oil mills. On average, the farming phase accounted for 76.3% of the EIs. Therefore, to reduce the impact of the virgin olive oils production, most of the efforts should be made especially in the farming phase. Despite the high variability between seasons and between independent replicates of the same farming system, intensive farming had significant higher impacts on most environmental impact categories than traditional rainfed farming, mainly due to the application of nitrogen fertilizer, plant protection products and herbicides. In terms of climate change, the environmental impact of the functional unit is in the ranges of 1.80-2.41, 1.59-2.78 and 2.28-3.26 kg of CO2 eq. for traditional rainfed, irrigated and intensive, respectively. C footprint was negative and averaged -5.5, -4.3 and -2.7 kg CO2 eq. Olive groves are efficient atmospheric CO2 sinks mainly by fixing CO2 into permanent and non-permanent trees structures. The lower intensification of the traditional rainfed groves contributed more in mitigating the increase of atmospheric CO2. Finally, the C footprint and C balance are negative, especially in traditional irrigated and intensive farming. The application of organic sources of fertilizer and the implementation of temporary spontaneous cover crops, both technically and economically feasible, are sound strategies to achieve a positive carbon balance and reduce the impacts of olive cultivation.

A wavelet neural control scheme for a quadrotor unmanned aerial vehicle.

Wavelets are designed to have compact support in both time and frequency, giving them the ability to represent a signal in the two-dimensional time-frequency plane. The Gaussian, the Mexican hat and the Morlet wavelets are crude wavelets that can be used only in continuous decomposition. The Morlet wavelet is complex-valued and suitable for feature extraction using the continuous wavelet transform. Continuous wavelets are favoured when high temporal and spectral resolution is required at all scales. In this paper, considering the properties from the Morlet wavelet and based on the structure of a recurrent high-order neural network model, a novel wavelet neural network structure, here called a recurrent Morlet wavelet neural network, is proposed in order to achieve a better identification of the behaviour of dynamic systems. The effectiveness of our proposal is explored through the design of a decentralized neural backstepping control scheme for a quadrotor unmanned aerial vehicle. The performance of the overall neural identification and control scheme is verified via simulation and real-time results.This article is part of the theme issue 'Redundancy rules: the continuous wavelet transform comes of age'.

Role of the femoral vein doppler in acute heart failure patients: results from a prospective multicentric study.

BACKGROUND AND OBJECTIVE: The aim of our study is to define the role of Pulsed-Doppler (PW-Doppler) Ultrasound of the Common Femoral Vein (CFV) in the assessment of dilatation Inferior Vena Cava (IVC), probability of Pulmonary Hypertension (PH), Tricuspid Regurgitation (TR), and Tricuspid annular plane systolic excursion (TAPSE). METHODS: This is a prospective two-hospital study in 74 patients admitted with acute heart failure (AHF). We performed PW-Doppler ultrasound of the common femoral vein, Point of Care (POC) cardiac ultrasonography and assessment of the IVC at the time of admission, as well as PW-Doppler and ultrasound of the IVC at hospital discharge. RESULTS: The detection of a pulsatile flow (138 scans) had an excellent ROC curve for the detection of IVC greater than 2cm (AUC 0.931, Sn 95%, Sp 90%, PPV 93%, NPV 94%) with an Odds Ratio (OR) of 211.2 (95% confidence interval 48.13-926.72). The pulsatility of the flow also had the highest performance in the detection of PH (AUC 0.8, Sn 95%, Sp 64%, PPV 84%, NPV 84%) and in the detection of moderate-severe TR (AUC 0.79, Sn 95%, Sp 67%, PPV 88%, NPV 78%). If the flow is continuous, we can reasonably rule out diminished TAPSE (NPV 89%). CONCLUSSION: Detection of PW-Doppler flow of the CFV may be an alternative window for the detection of an IVC dilation of 2cm, significant TR, and the likelihood of high PH in acute heart failure. It also allows us to reasonably rule out dysfunction of the right ventricle in cases of normality in these patients.

Consensus Document of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC), the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) and the Spanish Society of Anesthesiology and Resuscitation (SEDAR) on Tracheotomy in Patients with COVID-19 Infection. / Documento de consenso de la Sociedad Española de Medicina Intensiva, Crítica, y Unidades Coronarias (SEMICYUC), la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC) y la Sociedad Española de Anestesiología y Reanimación (SEDAR) sobre la traqueotomía en pacientes con COVID-19.

The current COVID-19 pandemic has rendered up to 15% of patients under mechanical ventilation. Because the subsequent tracheotomy is a frequent procedure, the three societies mostly involved (SEMICYUC, SEDAR and SEORL-CCC) have setup a consensus paper that offers an overview about indications and contraindications of tracheotomy, be it by puncture or open, clarifying its respective advantages and enumerating the ideal conditions under which they should be performed, as well as the necessary steps. Regular and emergency situations are displayed together with the postoperative measures.

[Consensus document of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC), the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) and the Spanish Society of Anesthesiology and Resuscitation (SEDAR) on tracheotomy in patients with COVID-19 infection]. / Documento de consenso de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (SEMICYUC), la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC) y la Sociedad Española de Anestesiología y Reanimación (SEDAR) sobre la traqueotomía en pacientes con COVID-19.

The current COVID-19 pandemic has rendered up to 15% of patients under mechanical ventilation. Because the subsequent tracheotomy is a frequent procedure, the three societies mostly involved (SEMICYUC, SEDAR and SEORL-CCC) have setup a consensus paper that offers an overview about indications and contraindications of tracheotomy, be it by puncture or open, clarifying its respective advantages and enumerating the ideal conditions under which they should be performed, as well as the necessary steps. Regular and emergency situations are displayed together with the postoperative measures.

Galectin-1 in stable liver transplant recipients.

INTRODUCTION: The achievement of a state of tolerance and minimization of the immunosuppressive load form part of the "Holy Grail" in solid organ transplantation. Galectin-1 recently has been described to be involved in the maintenance of a tolerant environment, but there is no evidence of its role in human liver transplantation. The aim of our study was to measure the serum levels of galectin-1 in stable liver transplant recipients. METHODS: Serum levels of galectin-1 were determined in 30 stable liver transplant recipients who had been free of rejection episodes for at least 8 years. Fifteen patients with an acute rejection episode and 34 healthy subjects were used as the control group. RESULTS: The concentrations of galectin-1 were significantly higher in stable liver transplant recipients compared with healthy subjects and with the acute rejection group. CONCLUSIONS: These preliminary results indicate that galectin-1 is upregulated in stable liver transplant recipients. Thus, our results extend the recent findings that galectin-1 may play an immune-suppressive role in liver transplantation. It remains to be established whether it might help to induce tolerance in liver transplantation.

Modifications induced by atherogenic diet in the capacity of the arterial wall in rats to respond to surgical insult.

A study was made of events occurring in the arterial wall of the rat after administration of an atherogenic calcification-inducing diet and of vascular response in a model of combined metabolic aggression (atherogenic, calcification-inducing diet) and surgical aggression (adventitial resection). Female Sprague-Dawley rats were fed an atherogenic, calcification-inducing diet for 24 consecutive days, after which half the rats returned to standard diet (group I, n = 12) and the other half (group II) underwent resection of the adventitia on a segment of common iliac artery on day 25 before returning to standard diet. Normolipemic rats and rats that underwent adventitial resection without the atherogenic, calcification-inducing diet were used as the control groups. The rats were killed at 10 min, 1 and 24 h, 5, 14, 21, 30, 50, 70, 120 and 180 days. Morphologic studies were made with light microscopy and electron microscopy (scanning and transmission), as well as biochemical studies. Monocyte adherence and infiltration of the arterial intima, thickening of the subintimal space, the presence of monocyte-macrophages, calcification in the medial layer, intense adventitial fibrosis, and vacuolization of the endothelial cells of the adventitial microvessels were common findings in the two groups receiving the atherogenic, calcification-inducing diet. However, these groups differed in the intensity of calcification: the deep part of the medial layer did not become calcified when the adventitia was resected. Moreover, adventitial regeneration was delayed in group II with respect to the animals that underwent adventitial resection without atherogenic, calcification-inducing diet. We conclude that this diet induced atherosclerotic lesions in the vessel wall and inhibited adventitial regeneration in the rats that underwent resection.

Atherogenic effects of cyclosporine in an experimental model of arterial autograft.

One of the effects attributed to CsA is a possible acceleration of atherogenic processes, which contributes to the failure of transplanted organs. This study was undertaken to evaluate the effect of CsA and two vehicles, cremophor and ethanol, in an experimental model of arterial autograft in the rat. Female Sprague-Dawley rats were distributed into 3 study groups: Group 1 (control) had an arterial autograft in the common iliac artery without pretreatment; group 2 (CsA-cremophor) animals were pretreated with a daily dose of CsA (5 mg/kg, Sandimmun) for 4 days before the autograft was made; and group 3 (CsA-ethanol + Tween) animals were pretreated for 4 days before implantation of the autograft with CsA in a vehicle of ethanol + Tween at the same dose as used in group 2 (5 mg/kg). The study periods were 7, 14, 21, 30, and 50 postoperative days. Studies were made by optical microscopy, transmission electron microscopy, scanning electron microscopy, and autoradiography. Evaluation of the results showed that in the control group the postoperative repair process lead to formation of an intimal neolayer throughout the entire surgical zone, with scant participation of white cells. Group 2 (CsA-cremophor) had a marked increase in luminal thrombogenicity, important adhesion and infiltration of white cells, loss of smooth muscle cells in the medial layer, and atherogenic degeneration of the medial layer. The generation of the neointimal layer is delayed by 2 weeks with respect to the control group. However, once the neointimal begins to form, its thickness increases rapidly, reaching values similar to those seen in the control group at 50 days. The myointima also shows atherogenic characteristics, such as monocyte-macrophage infiltration and dystrophic calcification. In group 3 (CsA-ethanol+Tween, that is, CsA in a nonoleaginous vehicle), the effects were similar to those seen in group 2 (CsA-cremophor), with a reduction in the presence of lipid-laden cells in the medial layer. Based on these observations, we conclude that CsA per se induced atherogenic changes in the repair process of the arterial lesion that were independent of the vehicle of administration. CsA delayed, but did not inhibit, formation of a myointima and the myointima formed exhibited atherogenic characteristics. The most important effects were noted in the medial layer, which experienced intense degeneration.

Effect of phosphatidylcholine on the process of peritoneal adhesion following implantation of a polypropylene mesh prosthesis.

The postimplantation peritoneal adhesions formed with some biomaterials continue to represent a serious problem when these biomaterials are placed in contact with the organs of the abdominal cavity. The objective was to test the effects of phosphatidylcholine (PC) in the attempt to modulate the adhesive process, thus improving the biomaterial/visceral peritoneum interface. We have carried out an experimental study using the New Zealand white rabbit, implanting a 7 x 5 cm2 polypropylene prosthesis into the anterior abdominal wall in such a way that it replaced all the tissue layers and was in contact with the intestinal loops. Three study groups were established: group I (control), in which only implantation of the biomaterial was performed; group II, in which the prosthesis was pretreated with a solution of PC; and group III, in which the implants were treated as in group II and the animals underwent intraperitoneal administration of 10 ml of the same solution. The animals were killed on postimplantation day 14. The total surface of the prosthesis occupied by adhesions was measured and light and scanning electron microscopy were performed to analyse the healing process. In comparison with the controls, groups II and III did not present significant differences with respect to the resistance or extension of the adhesions. The microscopic results showed a rapid formation of disorderly and well-vascularised scar tissue enveloping the entire prosthesis. Thus, PC was unable to modulate the process of adhesion formation between the prosthesis and the organs of the abdominal cavity; nor did it induce changes in the cells of sufficient importance to alter the results of the healing process in the presence of this biomaterial.

Improvement of the tissue integration of a new modified polytetrafluoroethylene prosthesis: Mycro Mesh.

We studied the behaviour of the different tissue interfaces formed on a new type of prosthesis used for the repair of abdominal wall defects, Mycro Mesh (W. L. Gore and Ass., Flagstaff, AZ, USA), which consists of perforated layers of polytetrafluoroethylene (PTFE). In 20 New Zealand white rabbits, a full-thickness (except skin) 7 cm x 5 cm defect was created in the anterior abdominal wall. The defects were repaired with a prosthetic implant (Mycro Mesh) that was placed in direct contact with abdominal viscera and subcutaneous tissue. At 14, 30, 60 and 90 d post-implantation, samples were obtained from the tissue interfaces formed between the prosthesis and subcutaneous tissue, visceral peritoneum and receptor tissue, respectively. Samples were studied by optical microscopy and scanning electron microscopy. The immunohistological study was made with RAM-11, a monoclonal antibody specific for rabbit macrophages. Tensile strength was measured with an Instron tensiometer using 2 cm wide strips obtained parallel to the shorter axis of the implant. Strips included the prosthesis and two anchor zones on the receptor tissue. Macroscopically, the prosthesis induced little adhesion formation on the visceral peritoneum interface. Microscopically, an organized neoperitoneum and abundant tissue formed on the subcutaneous interface. In the prosthesis perforations, bridges of tissue linked the peritoneal and subcutaneous sides. The macrophage response decreased significantly in intensity between day 14 and day 90 (Student-Newman-Keuls test, P = 0.01). Tensile strength increased significantly (Wilcoxon test, P < 0.05) at every study period. To conclude: the Mycro Mesh prosthesis proved suitable for implantation in sites where it comes in contact with abdominal viscera and it provided good support for the formation of an organized neoperitoneum; the perforations in the prosthetic material improved implant integration; the macrophage response was not altered by the biomaterial and the tensile strength of the prosthesis increased as scar tissue formation and tissular integration of the prosthesis progressed.

In vitro interaction of bacteria with polypropylene/ePTFE prostheses.

The infection of an implanted prosthetic material can have serious consequences on the tissue integration of the implant and the scarring process in the host, and may even necessitate replacement of the prosthesis. This study was designed to explore the in vitro effects of Staphylococcus aureus (Sa) and Staphylococcus epidermidis (Se) on polypropylene (PL) and expanded polytetrafluoroethylene (ePTFE) prostheses. Fragments of PL and ePTFE were placed in a medium previously inoculated with Sa, Se or Sa + Se (1 x 10(8) cfu Sa or/and Se). Bacterial effects on the biomaterials were evaluated for 30 days through scanning electron microscopy (SEM). In order to confirm the presence of bacteria on the prostheses, specimens were Gram stained and challenged with an antibody against protein-A (a specific Sa bacterial wall component). In both methods, specimens were examined by light microscopy. The presence of bacteria as microcolonies or biofilms was detected at PL filament cross-over regions after 30 days. Bacterial colonization of the ePTFE fragments was observed in internodal areas, which led to the deformation of prosthetic filaments. The present findings indicate that Sa and Se colonize the cross-over regions of the PL filaments, whereas in ePTFE prostheses, it is the internodal areas which are mostly affected. The latter areas are of difficult access to defence agents.

Possible role of brown adipose tissue as a mediator during cyclosporine-A treatment.

Cyclosporine-A (CsA) is a potent immunosuppressor used successfully to control rejection in organ transplantation. According to the most recent evidence, this drug modifies the lipid metabolism of the patient, provoking a rise in the blood lipids, constituting an important risk factor for acceleration of the atherogenic process. Taking into account that brown adipose tissue (BAT) constitutes the major storage site for cholesterol and triglycerides in the rat, and given the apparent lack of references about the implications of CsA on this tissue in the literature, we proposed to study the possible morphological changes occurring in BAT following the administration of this drug. Two groups of female Sprague-Dawley rats were set up, the control group and a treated group in which each animal received subcutaneous injection of 5 mg/kg body weight/day of CsA. After 4, 11, 25 and 34 days of treatment, subgroups of animals were sacrificed and the brown adipose tissue removed was apportioned for subsequent microscopic assessment. The greatest degree of atypia and activity in the BAT was observed after administration of 11 doses of the drug, at which point there was a marked reduction in the cell size with loss of lipidic coalescence. With subsequent doses, the tissue slowly initiated a process of recovery. CsA also induced morphological changes in the BAT that, in the early stages of the study, appeared to be correlated with a lipolytic response of the tissue to the drug; thus, the BAT may be acting as a system to eliminate the excess of lipids in the blood provoked by CsA administration, while toward the end of treatment, there was a certain stability between the drug and the activity of the brown adipose tissue, and a tendency to reach a balance between lipolysis and lipogenesis.

Assessment of cyclosporine A-induced ultrastructural changes in vascular wall using an experimental arterial autograft model.

The objective of this ultrastructural study was to assess the effects of cyclosporine A (CsA) in an experimental model of arterial autograft. Fifty female Sprague-Dawley rats weighing 250-300 g were employed. Using a microsurgical technique, an arterial autograft measuring approximately 5 mm in length was placed in the right common iliac artery. Two groups were established: group I (control), consisting of 25 animals subjected only to arterial autograft; and group II (pre- and postoperative CsA), also consisting of 25 animals which received a daily subcutaneous dose of 5 mg/kg CsA (Sandimmun, Sandoz) on the four days preceding the surgery and thereafter, until sacrifice. The animals were sacrificed on postoperative day 7, 14, 21, 30 and 50. The specimens (autografts) obtained were studied under transmission and scanning electron microscopes. In the control group, the process of endothelialization of the graft was completed by day 14. In the CsA-treated group, restoration of the endothelium took 50 days. The development of intimal hyperplasia was delayed in the treated group. There were no morphological changes in its structure when compared to the control group. The tunica media had thinned in the treated grafts, with loss of smooth muscle cells, fragmentation and lysis of the elastic lamina, presence of lipid-filled macrophages, and muscle cells with cytoplasmic lipid vacuoles. In our opinion, these results suggest that the action of CsA mainly targets on the endothelium and smooth muscle cells, exerting a toxic effect in an in vivo arterial graft model.

Inflammatory cells induce neointimal growth in a rat arterial autograft model.

Subendothelial invasion by leukocytes is a sign of intimal thickening in arteriosclerosis and in the response of a vessel to mechanical damage. Our study was designed to establish whether these cells are implicated in the formation of a neointima in an autologous arterial graft model in the rat and to evaluate the effects of cyclosporin A (CsA). Three study groups were established according to whether the animals were treated with CsA-Cp (Sandimmun), CsA-Et (ethanol vehicle) or received no treatment (control group). Both drug forms were administered (5 mg/kg/day, s.c.) from 4 days prior to surgery until the time of sacrifice. Antibodies specific for lymphocytes (CD4, CD8), monocytes/macrophages-ED1, smooth muscle alpha-actin and the von Willebrand factor (vWF) were used to identify the cells in the grafted arterial wall. In control grafts, the neointima had formed by 2 weeks post-implant. However, the cells comprising this layer generally presented no positivity whatsoever towards the antibodies employed. At 50 days, the new layer was observed to be formed by a vWF-positive endothelium and alpha-actin-positive cells. In all three groups, several polymorphonuclear (PMN) cells adhered to the denuded luminal surface from 7 days onwards. In the treated animals, neutrophils and monocytes were seen to infiltrate intimal and medial layers during the later post-implant stages. Around the third week post-implant, the neointima had reached the grafted segment from the distal portion of the recipient artery, and by 50 days it was similar to that seen in control specimens. Our findings suggest that: a) neutrophils play a role in neointimal thickening in this arterial autograft model; and b) CsA promotes the adhesion and infiltration of neutrophils in the injured arterial wall.

A histopathological study of anoxic-resuscitated liver allografts.

The possibility of resuscitating livers after warm ischaemia has been recently suggested. The aim of the present investigation was to analyse the effects of anoxia on the morphology of hepatic cells, to determine whether these effects are reversible after providing a resuscitation period between warm ischaemia (WI) and cooling, and to study the behaviour of the resuscitated liver in the recipient organism. Ten female, Large-White pigs acted as donors for 10 recipient animals of the same kind who received an orthotopic liver graft. Recipients were divided into two groups depending on whether the livers they received had undergone a resuscitation period (Group I (n=5) where animal livers were subjected to 5 min warm ischaemia (WI) without resuscitation, and Group II (n=5) where the livers were subjected to 5 min WI followed by 5 min resuscitation). Morphological and ultrastructural studies of liver cells were performed using light and electron microscopy. ATP, ADP and AMP levels were determined in liver biopsies by high performance liquid chromatography (HPLC). Plasma AST and bilirubin levels in the two groups were compared 24 h after transplantation. After 5 min of anoxia, hepatocytes showed two morphological patterns in response to WI. Some were appreciably condensed with dark mitochondria, peroxisomes and some cytoplasmic vacuoles. Others showed electronlucent organelles, inflamed mitochondria with broken cristae and disorganized endoplasmic reticulum. Hepatocytes showed globular microvilli and bleb formation with migration towards the sinusoids. One hour after the revascularisation of the resuscitated livers, the hepatocytes showed nearly normal morphological characteristics. However, the hepatocytes of non-resuscitated organs continued to show alterations. Kupffer cells were activated in the livers of both experimental groups. Ultrastructural changes and total tissue adenine nucleotide (TAN) levels recovered completely in resuscitated livers soon after transplant. These results suggest that when short WI periods are followed by equivalent periods of resuscitation, the hepatocytes of transplanted livers recover from the effects of anoxia.

Effects of ischaemia-reperfusion and cyclosporin-A on cardiac muscle ultrastructure.

The present study investigates the effects on the cardiac muscle cell of two of the determining factors for the success of organ transplant; ischaemia-perfusion and immunosuppressive treatment with cyclosporin-A (CsA). To this end an abdominal, heterotopic heart transplant model in singenic Sprague-Dawley rats was employed. Three study groups were established: Group I (control, n = 15) animals undergoing heart transplant without treatment; Group II (n = 15) animals undergoing heart transplant and subjected to a daily dose of CsA in a cremophor vehicle (Sandimun) (5 mg/kg/sc); Group III (n = 15): animals undergoing heart transplant and administered a daily dose of pure CsA (5 mg/kg/sc). Recipient animals were sacrificed 7, 14, 21, 30 and 50 days after transplant. During the post-operative period, heart function was assessed by daily abdominal palpation. Graft specimens obtained at each follow-up period were subjected to light and transmission electron microscopy. Immunohistochemical analysis of specimens was performed using the rat macrophage-specific monoclonal antibody MCA-341. The ischaemia/reperfusion process induced considerable alteration to cardiac muscle cells of control animals. Effects, apparent after the first week of transplant, included mitochondrial swelling and loss of cristae, hypertrophy of the sarcoplasmic reticulum and structural changes to sarcomeres. Two weeks after transplant, the myocardium was infiltrated by inflammatory cells. These effects diminished 30 days post-transplant. Cardiac tissues of treated animals (groups II and III) showed similar behaviour although, in the latter group, mitochondrial damage was greater and intense myocardial fibrosis took place. Infiltration of cardiac muscle by white blood cells did not take place until 3 weeks post-implant. These results indicate: a) The ultrastructural changes detected in cardiac fibres of animals of the three study groups were attributable to the ischaemia/reperfusion process rather than to treatment with CsA; b) CsA appears to augment mitochondrial damage and myocardial fibrosis; c) the inflammatory response was delayed and reduced by the immunosupressant; and d) the cremophor administration vehicle did not seem to exert an independent toxic effect on the myocardium.

Function of inflammatory cells and neoral cyclosporin-A in heart transplant-associated coronary vasculopathy.

The role of Sandimmun Neoral (S-n) and the immune response in transplant-associated coronary vasculopathy (TACV) was evaluated in a Lewis (Lew)-to-Fischer-344 (F344) rat abdominal heterotopic heart transplant model. Some of the transplant recipients were treated with S-n (5mg/kg/day) for 14 days post-transplant, or until sacrifice. Grafts were subjected to immunohistochemical (ED1, CD4, CD8 and alpha-actin+ cells) analysis from day 7 to 100 post-transplant. Singenic controls did not develop TACV, irrespective of whether they had received the drug or not. TACV was detected in Lew-F344 transplants regardless of S-n administration with participation of ED1+, CD8+ and alpha-actin+ cells, although its incidence was lower in animals receiving prolonged S-n treatment. In this model, accelerated arteriosclerosis of the graft appeared to be related more to the rejection effect than to the action of the immunosuppressive agent.