International consensus recommendations on face transplantation: A 2-step Delphi study.

Face transplantation is a viable reconstructive approach for severe craniofacial defects. Despite the evolution witnessed in the field, ethical aspects, clinical and psychosocial implications, public perception, and economic sustainability remain the subject of debate and unanswered questions. Furthermore, poor data reporting and sharing, the absence of standardized metrics for outcome evaluation, and the lack of consensus definitions of success and failure have hampered the development of a "transplantation culture" on a global scale. We completed a 2-round online modified Delphi process with 35 international face transplant stakeholders, including surgeons, clinicians, psychologists, psychiatrists, ethicists, policymakers, and researchers, with a representation of 10 of the 19 face transplant teams that had already performed the procedure and 73% of face transplants. Themes addressed included patient assessment and selection, indications, social support networks, clinical framework, surgical considerations, data on patient progress and outcomes, definitions of success and failure, public image and perception, and financial sustainability. The presented recommendations are the product of a shared commitment of face transplant teams to foster the development of face transplantation and are aimed at providing a gold standard of practice and policy.

Miracles of science: Birth after uterus transplantation.

AIM: The concept of regaining childbearing ability via uterus transplantation (UTx) motivates many infertile women to pursue giving birth to their own children. This article provides insight into maternal and neonatal outcomes of the procedure globally and facilitates quality of care in related medical fields. METHODS: The authors searched ISI Web of Science, MEDLINE, non-PubMed-indexed journals, and common search engines to identify peer-review publications and unpublished sources in scientific reference databases. RESULTS: The feasibility of the procedure has been proven with 46 healthy children in 88 procedures so far. Success relies upon dedicated teamwork involving transplantation surgery, obstetrics and reproductive medicine, neonatology, pediatrics, psychology, and bioethics. However, challenges exist owing to donor, recipient, and fetus. Fetal growth in genetically foreign uterine allograft with altered feto-maternal interface and vascular anatomy, immunosuppressive exposure, lack of graft innervation leading to "unable-to-feel" uterine contractions and conception via assisted reproductive technology create notable risks during pregnancy. Significant portion of women are complicated by at least one or more obstetric problems. Preeclampsia, gestational hypertension and diabetes mellitus, elevated kidney indices, and preterm delivery are common complications. CONCLUSIONS: UTx has short- and long-term satisfying outcome. Advancements in the post-transplant management would undoubtedly lead this experimental procedure into mainstream clinical practice in the near future. However, both women and children of UTx need special consideration due to prematurity-related neonatal problems and the long-term effects of transplant pregnancy. Notable health risks for the recipient and fetus should be discussed with potential candidates for UTx.

A Rare Case of Castleman's Syndrome Presenting with a Mass in the Bifurcation of the Celiac Trunk.

INTRODUCTION: Castleman's disease is an extremely rare disease in the abdomen region characterized by benign lymphoepithelial proliferation. CASE PRESENTATION: We report a case of a 63-year-old female who presented with abdominal pain. Abdominal CT Angio and dynamic contrast-enhanced abdominal MRI revealed a mass lesion showing markedly contrast enhancement, no vascular invasion sign, and diffusion restriction lesion in the truncus coelicus bifurcation region. The mass was surgically resected completely. Pathological evaluation showed a hyaline-vascular type of Castleman's disease. CONCLUSION: Castleman's disease should be kept in mind in the differential diagnosis of an isolated intra-abdominal mass.

An Oroauricular Fistula After Mandibular Osteosarcoma Resection.

Bone tumors are rare malignancies and osteosarcoma is the most common malignant bone tumor. However, only 6% of all osteosarcomas occur in the mandible and maxilla 1. The location of these tumors also presents a unique set of challenges during resection and repair when compared to long bone tumors.

Let-Down Rhinoplasty in Patients With Cleft Lip Nose.

BACKGROUND AND OBJECTIVES: Rhinoplasty in patients with cleft lip nose (CLN) deformity is challenging. Cleft lip nose deformity primarily affects the nasal tip, columella, nostrils, alar base, floor, and septum. The needs of patients with CLN are quite different from those of patients who undergo primary rhinoplasty. Recently, the dorsal preservation rhinoplasty technique has gained popularity. We applied this technique to patients with CLN deformity to obtain better aesthetic and functional results. PATIENTS AND METHODS: Ten consecutive patients with indication for primary CLN reconstruction underwent let-down rhinoplasty. Rhinoplasties were performed using either the closed or open approach, with costal cartilage grafts and full-thickness skin grafts. A rhinoplasty outcome evaluation questionnaire was used to assess the results. Moreover, the use of the same questionnaire in prior patients allowed us to compare results between our previous and new techniques. RESULTS: The study included 6 female and 4 male patients, with ages ranging from 18 to 25 years. Only 1 patient had a history of bilateral cleft lip. Seven patients had a history of left-sided cleft lip, and 2 patients had right-sided cleft lip. Open-approach let-down rhinoplasty with costal cartilage grafts and full-thickness skin grafts was performed in 8 patients, whereas closed-approach let-down rhinoplasty with costal cartilage grafts was performed in 2 patients. Columellar struts and affected-side onlay costal cartilage grafts were used in all patients. All patients reported being satisfied with the let-down rhinoplasty outcome, and none complained of functional problems. However, nostril symmetry was not observed in some patients, particularly in patients who underwent closed-approach rhinoplasty. CONCLUSIONS: Combining open approach, full-thickness skin graft, costal cartilage graft, and let-down rhinoplasty shows promising and satisfactory outcomes in patients with CLN. However, further studies are required to confirm this observation.

The Ozkan Technique in Current Use in Uterus Transplantation: From the First Ever Successful Attempt to Clinical Reality.

Uterus-related infertility affects 3-5% of all young women, including Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, hysterectomy, or severe Asherman syndrome. For these women with uterus-related infertility, uterus transplantation is now a viable option. We performed the first surgically successful uterus transplant in September 2011. The Donor was a 22-year-old nulliparous woman. After five failed pregnancy attempts (pregnancy losses), ET attempts were discontinued in the first case, and a search for underlying etiology was performed, including static and dynamic imaging studies. Perfusion computed tomography revealed an obstructed blood outflow, particularly in the left anterolateral part of the uterus. In order to correct blood flow obstruction, a revision surgery was planned. By laparotomy, a saphenous vein graft was anastomosed between the left utero-ovarian and left ovarian vein. Perfusion computed tomography performed after the revision surgery confirmed the resolution of venous congestion and a decrease in uterine volume as well. Following surgical intervention, the patient was able to conceive after the first embryo transfer attempt. The baby was delivered with cesarean section at 28 weeks' gestation due to intrauterine growth restriction and abnormal Doppler ultrasonography findings. Following this case, our team performed the second uterus transplantation in July 2021. The recipient was a 32-year-old female with MRKH syndrome, and the donor was a 37-year-old multiparous braindead woman due to intracranial bleeding. After the transplant surgery, the second patient experienced menstrual bleeding six weeks after the operation. Seven months after the transplant, in the first ET attempt, pregnancy was achieved, and she delivered a healthy baby at 29 weeks of pregnancy. Uterus transplantation from a deceased donor is a feasible option for treating uterus-related infertility. When confronted with recurrent pregnancy losses, vascular revision surgery via arterial or venous supercharging could be an option in order to deal with focal underperfused areas defined by imaging studies.

Facial Expression after Face Transplant: An International Face Transplant Cohort Comparison.

BACKGROUND: Assessment of motor function restoration following face transplant (FT) is difficult, as standardized, bilateral tests are lacking. This study aims to bolster support for software-based analysis through international collaboration. METHODS: FaceReader (Noldus, Wageningen, The Netherlands), a facial expression analysis software, was used to analyze posttransplant videos of eight FT patients from Boston, Massachusetts (range, 1 to 9 years after transplant), two FT patients from Helsinki, Finland (range, 3 to 4 years after transplant), and three FT patients from Antalya, Turkey (range, 6.5 to 8.5 years after transplant). Age-matched healthy controls from respective countries had no history of prior facial procedures. Videos contained patients and controls performing facial expressions evaluated by software analysis using the Facial Action Coding System. Facial movements were assigned intensity score values between 0 (absent) and 1 (fully present). Maximum values were compared with respective healthy controls to calculate percentage restoration. RESULTS: Of 13 FT patients, eight patients were full FT, five patients were partial FT, and two patients were female patients. Compared with healthy controls, the median restoration of motor function was 36.9% (interquartile range, 28.8% to 52.9%) for all patients with FT ( P = 0.151). The median restoration of smile was 37.2% (interquartile range, 31.5% to 52.7%) for all patients with FT ( P = 0.065). When facial nerve coaptation was performed at the distal branch level, average motor function restoration was 42.7% ± 3.61% compared with 27.9% ± 6.71% at the proximal trunk coaptation level ( P = 0.032). Use of interpositional nerve grafts had no influence on motor outcomes. CONCLUSIONS: Software-based analysis is suitable to assess motor function after FT. International collaboration strengthens outcome data for FT. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Rare Relationship Between the Right Hepatic Artery and Common Hepatic Duct in Living Donor Right Hepatectomy.

In living donor liver transplant, it is vital to perceive the hepatic artery anatomy and its variants. In the normal hepatic artery pattern, the common hepatic artery originates from the celiac artery to form the proper hepatic artery and gastroduodenal artery. The proper hepatic artery divides into right and left branches that supply the right and left lobes of the liver, respectively. Here, we report a rare variation of the right hepatic artery that was detected during a living liver right lobe hepatectomy. A 59-year-old man with alcoholic liver cirrhosis underwent living donor liver transplant. The patient's niece (a 47-year-old woman) volunteered to be a living donor. During the hilar dissection, we noticed that the anterior and posterior branches of the right hepatic artery passed through points anterior and posterior to the common hepatic duct, respectively. The right anterior hepatic artery and the right hepatic artery were divided separately. Although previously defined classifications have described anatomical variations of origin, branching, and course of hepatic artery, the topographical relationship of the anterior right hepatic artery and the posterior right hepatic artery versus the common hepatic duct has not been a matter of concern. Awareness must be maintained of this rare anatomical course of the right hepatic artery, especially in living liver right lobe donors. In the event of donors with rare variations, living donor liver transplant should be performed by an experienced team.

Turkish HPB Surgery Association consensus report on hepatic cystic Echinococcosis (HCE).

Objectives: Cystic Echinococcosis (CE) is one of the important problems of the Eurasian region. We aimed to prepare a consensus report in order to update the treatment approaches of this disease. This study was conducted by Turkish HPB Surgery Association. Material and Methods: This study was conducted with the modified Delphi model. For this purpose, we conducted a three-stage consensus-building approach. Results: Six topics, including diagnosis, medical treatment, percutaneous treatment, surgical treatment, management of complications and posttreatment follow-up and recurrences in HCE were discussed. Conclusion: The expert panel made recommendations for every topic.

Management of Spontaneous Major Rectus Sheath Hematoma in a COVID-19 Patient: A Case Report and Literature Review.

A rectus sheath hematoma, which is mostly encountered due to abdominal traumas or anticoagulant use, can be challenging, and a delayed diagnosis may lead to hypovolemic shock and even death. In this study, we aimed to present the management of a case of rectus sheath hematoma that developed in a patient who was hospitalized and under coronavirus disease 2019 (COVID-19) treatment. A 70-year-old female patient was admitted to the intensive care unit (ICU) due to respiratory failure and developed a sudden onset of tachycardia and hypotension. The patient was then diagnosed with a rectus sheath hematoma and after ensuring hemodynamic stability she was treated with angiographic embolization. Following the treatment, the patient remained hemodynamically stable and a control computed tomography (CT) revealed regression in the hematoma. Rectus sheath hematomas especially accompanied by additional comorbidities or aggressive surgical interventions may result in high mortality rates in the early period. It should also be kept in mind that during the COVID-19 pandemic, which has affected the world in the last two years, rectus sheath hematomas may be the underlying cause of sudden hypotension and abdominal distension, and it should not be forgotten that angiographic embolization performed by experienced interventional radiologists is the mainstay of treatment in cases where hemodynamic stability can't be achieved.

Magnetic Nanoparticle-Based Electrochemical Sensing Platform Using Ferrocene-Labelled Peptide Nucleic Acid for the Early Diagnosis of Colorectal Cancer.

Diagnostic biomarkers based on epigenetic changes such as DNA methylation are promising tools for early cancer diagnosis. However, there are significant difficulties in directly and specifically detecting methylated DNA regions. Here, we report an electrochemical sensing system based on magnetic nanoparticles that enable a quantitative and selective analysis of the methylated septin9 (mSEPT9) gene, which is considered a diagnostic marker in early stage colorectal cancer (CRC). Methylation levels of SEPT9 in CRC samples were successfully followed by the selective recognition ability of a related peptide nucleic acid (PNA) after hybridization with DNA fragments in human patients' serums and plasma (n = 10). Moreover, this system was also adapted into a point-of-care (POC) device for a one-step detection platform. The detection of mSEPT9 demonstrated a limit of detection (LOD) value of 0.37% and interference-free measurement in the presence of branched-chain amino acid transaminase 1 (BCAT1) and SRY box transcription factor 21 antisense divergent transcript 1 (SOX21-AS1). The currently proposed functional platform has substantial prospects in translational applications of early CRC detection.

Major Surgical Resections in Abdominopelvic Sarcomas: Clinical Features and Results of 38 patients: A Tertiary-Center Experience.

Introduction: Sarcomas with mesenchymal origin located in the abdominal cavity or retroperitoneal space are rare. They might reach large dimensions due to the non-specific and late onset of clinical symptoms. In this study we aim to provide the outcomes of 38 cases. Methods: Thirty-eight patients, whose data had been registered and analyzed completely in a prospective manner, were enrolled in the study. Demographic Findings, Primary-Recurrent Status of the disease, surgical method applied (R0-1-2), additional organ resections, Morbidity and Mortality rates, HIPEC application, Histopathological results and overall survival outcomes during follow-up were evaluated in the enrolled cases. Results: Thirty-eight (38) patients were operated on due to soft tissue sarcomas located in the abdominal and retroperitoneal area. The mean age of patients was 57.63 +- 15.38. The localization rates of retroperitoneal, abdominal and visceral tumors were 28%, 58%, and 12%, respectively. The mean tumor size was 12.96 cm +- 9.62. Twenty-seven patients (71%) underwent R0 resection, 7 patients (18%) underwent R1 resection, 4 patients (10%) underwent R2 resection. Additionally, sarcomatosis was detected in 6 patients and these patients underwent Cytoreductive Surgery+HIPEC. The first 30-day mortality and morbidity rates were 10.5% (4 patients) and 44% (17 patients), respectively. Conclusion: Surgery is the gold standard treatment of this condition. The most important stage in the management of the condition is the discussion of these cases in multidisciplinary teams in centers experienced in this disease in terms of prognosis and local recurrence and deciding on the treatment strategy based on these discussions.

Birth of a Healthy Baby 9 Years After a Surgically Successful Deceased Donor Uterus Transplant.

OBJECTIVE: To describe surgical procedures, previous failed pregnancies, methods for overcoming pregnancy failure and, most importantly, birth of a healthy infant, in a uterus transplantation from a deceased donor. BACKGROUND: Majority of uterus transplants have involved live donors, but several advantages make deceased donor transplantation a practicable option, principally by eliminating surgical risks to the live donor. METHODS: Uterus transplantation from a deceased donor was performed in September 2011 in Turkey. After 5 miscarriages, perfusion computed tomography revealed an obstructed blood-outflow. To overcome this blood flow obstruction, a saphenous vein graft was anastomosed between utero-ovarian and left ovarian vein with laparotomy. Follow-up computed tomography confirmed resolution of venous congestion and a decrease in uterine volume. RESULTS: Following vascular augmentation surgery, fetal cardiac activity were observed 28 days after the first embryo transfer attempt. Preterm premature rupture of the membranes was diagnosed at 19 weeks' gestation. Cesarean section was planned at 28 weeks' gestation due to intrauterine growth restriction and suspected preeclampsia. A healthy 760 g male baby was delivered. The baby was discharged from the neonatal intensive care unit 79 days after delivery in good condition weighing 2475 g. CONCLUSIONS: Deceased donor uterus transplantation is a reasonable approach for treating uterine factor-related infertility. In case of recurrent miscarriages, regional vascular augmentation by arterial or venous supercharging may be required to overcome regional misperfused regions determined by imaging studies.

Effect of L-carnitine on regeneration in experimental partial hepatectomy model in rats.

BACKGROUND: In cases of major liver resections or ischemic damage made by the pringle maneuver, agents that increase regeneration or manage ischemic reperfusion injury have become a fascinating topic for researchers. The aim of this study is to see how systemic L-carnitine, an antioxidant with thorough research behind it, affects liver regeneration after major hepatectomy in a rat experimental hepatectomy (two-thirds liver resection) model. METHODS: The liver regeneration was evaluated in this study using a rat hepatectomy model developed in the General Surgery Clinic of Health Sciences University, Umraniye Education and Research Hospital's Laboratory. In the experiment, 15 male and 15 female Wistar Albino rats weighing between 250 and 300 g were used in a way that the genders were mixed. In each group, three groups were formed, including male and female rats randomly selected and ten rats. Gcontrol: 70% hepatic resection + intraperitoneal 0.9% saline, GSham: After laparotomy, the abdomen was closed again without any procedure, Gcarnitine: 70% hepatic resection + intraperitoneal 100 mg/kg L Carnitine was applied. It was applied systemically to GSham and Gcarnitine groups and the same procedure was applied to rats for 4 days at the same time without any restrictions. On the 5th day, the abdomen was entered with relaparotomy after sacrification and liver regeneration was evaluated macroscopically and recorded in the forms developed for each subject. Later, liver tissue was resected and microscopically recorded by measuring mitotic index, binuclear hepatocyte, gall duct proliferation, dilation in central veins, and cell proliferation in the parenchyma. The results obtained were evaluated statistically. RESULTS: According to the results, the L-carnitine group had a statistically significant increase in overall regeneration scoring after hepatectomy in the histopathological assessment as compared to the control group. CONCLUSION: It is thought that L-carnitine, whose many positive effects have been shown experimentally and clinically, has a positive effect on liver regeneration and immunohistochemical researches is required to elucidate this pathway.

The Role of CO-RADS Scoring System in the Diagnosis of COVID-19 Infection and its Correlation with Clinical Signs.

BACKGROUND: Computed tomography (CT) evaluation systematics has become necessary to eliminate the difference of opinion among radiologists in evaluating COVID-19 CT findings. INTRODUCTION: The objectives of this study were to evaluate the efficiency of CO-RADS scoring system in our patients with COVID-19 as well as to examine its correlation with clinical and laboratory findings. METHODS: The CO-RADS category of all patients included in the study was determined by a radiologist who did not know the rtRT-PCR test result of the patients, according to the Covid-19 reporting and data system of Mathias Prokop et al. Results: A total of 1338 patients were included. CT findings were positive in 66.3%, with a mean CO-RADS score of 3,4 ± 1,7. 444 (33.1%) of the patients were in the CO-RADS 1-2, 894 (66.9%) were in the CO-RADS 3-5 group. There were positive correlations between CO-RADS score and age, CMI, hypertension, diabetes mellitus, chronic pulmonary diseases presence of symptoms, symptom duration, presence of cough, shortness of breath, malaise, CRP, and LDH, while CORADS score was negatively correlated with lymphocyte count. The results of the ROC analysis suggested that those with age ≥40 years, symptom duration >2 days, CMI score >1 and/or comorbid conditions were more likely to have a CO-RADS score of 3-5. CONCLUSION: The CO-RADS classification system is a CT findings assessment system that can be used to diagnose COVID-19 in patients with symptoms of cough, shortness of breath, myalgia and fatigue for more than two days.

Early detection onset of flap failure using near infrared spectroscopy.

BACKGROUND: Near-infrared spectroscopy (NIRS) is widely used to assess flap perfusions by measuring tissue oxygen saturation (StO2). However, the StO2 level for the onset of perfusion failure is still a controversial issue. AIM: This study proposes a new threshold of StO2 level for detecting the onset of perfusion failure as early as possible to increase flap salvage rates. METHODS: Twenty patients undergoing flap surgery were included in this study - 13 flaps were implemented to cover defects that occurred due to trauma and 7 flaps to hide imperfections that occurred after cancer treatment. Thirteen flaps were in the lower extremity, six in the mandible, and one in the breast. NIRS was used to measure StO2 in 240 flap regions of the 20 patients to determine flap viability using descriptive statistics. RESULTS: The mean StO2 values from healthy flap and control regions were obtained as 81.6% ± 0.36 and 82% ± 0.18, respectively. The lowest StO2 value of 77.2% was defined as the onset of a vascular complication at a probability of 99.74% by subtracting three times the standard deviation from the mean StO2 of healthy flaps. Vascular complications were observed from 21 regions in the four flaps with StO2 values lower than 77.2%, but only one was lost. CONCLUSION: The threshold value for the onset of perfusion failure was a 5% decrease from the expected value, much lower than previously described thresholds that may facilitate the detection of perfusion failure in the early stage and increase salvage rates in flap revisions.

Evaluation of stoppage time due to field injuries in professional football games: do players really need medical help so often?

This study aimed to identify the incidence of stoppage time due to field injuries in professional football (soccer) games and to evaluate if the players involved really need medical care and whether team physicians deal with fake injuries. A total of 893 injury time-outs occurred leading to 956 treatments during 266 matches included in the study. The mean stoppage time was 88.7 ± 34.4 seconds. Less than one fifth of the injuries (17.4%) resulted in an impossibility to complete the game. The overall time-loss injury incidence which led players to miss the next game was 9.1/1000 match-hours (n = 80, 8.4% of all injuries). The players on teams in the lead at the time of the incident had significantly higher injury time-out incidence than players on teams who were losing (p < 0.05). Increasing the knowledge of team physicians, coaches, referees, and rule-makers about the medical needs of players during the game will help to identify the behaviour pattern of players.

The effects of home confinement on physical activity level and mental status in professional football players during COVID-19 outbreak.

OBJECTIVES: The coronavirus outbreak caused significant changes in football around the world, such as the suspension of leagues and home isolation of players, etc. The main purpose of the present study was to assess the psychological impacts of lockdown and similar restrictions on professional football players during the coronavirus pandemic. MATERIALS AND METHODS: The players from 36 professional football teams (n = 977) among Turkish Super League and First League teams were invited to complete a questionnaire including the Center for Epidemiologic Studies Depression Scale (CES-D), Impact of Event Scale-Revised Scores (IES-R) and short form of International Physical Activity Questionnaire (IPAQ). RESULTS: The online survey was completed by 237 players (24.3%). The mean number of self-quarantine day of participants was 26.9 ± 6.2 days. The median CES-D Scale and IES-R scores were 6.0 (min:0, max:42) and 23.0 (min:0, max:59), respectively. IPAQ scores of the players showed that four-fifths of the players still maintain high physical activity levels. There were negative, very weak and significant correlations between CES-D score and being married (r = -0.146, p = 0.024), as well as between CES-D score and IPAQ-Walking (r = -0.189, p = 0.004). A significant positive very weak correlation was observed between CES-D score and self-quarantine days (r = 0.148, p = 0.024). IPAQ-Walking was an independent predictor of CES-D. CONCLUSION: These findings support that maintaining regular physical activity and routinely exercising in a safe home environment is one of the most important strategies to ensure healthy mental state.

The relationship between COVID-19 and HLA in kidney transplant recipients, an evaluation of predictive and prognostic factors.

INTRODUCTION: The purpose of this study was to determine the predictive and prognostic factors for COVID-19 infection and its relationship with human leukocyte antigen (HLA) in kidney transplant recipients. MATERIAL AND METHOD: Three hundred fifty kidney transplant recipients were included in the study. Recipients were divided into two groups: COVID-19(+) (n = 100) and control (n = 250). The relationships between HLA frequencies, COVID-19 infection, and prognostic factors (age, donor type, immunosuppression protocol, etc.) were then evaluated. Logistic regression analysis, heatmap, and decision tree methods were used to determine predictive and prognostic factors. The study was performed retrospectively. RESULTS: Advanced age and deceased transplantation emerged as predictive of SARS-CoV-2 infection, while the presence of HLA-A*11, the HLA match ratio, and high-dose tacrolimus were identified as prognostic factors in kidney transplant recipients. HLA-A10, HLA-B*13, HLA-B22, and HLA-B*55 were shown to be associated with SARS-CoV-2 infection at univariate analysis, and HLA-B*57, HLA-DRB1*11, and HLA-DRB1*13 at logistic regression analysis. CONCLUSION: HLA-A10, HLA-B*13, HLA-B*55, HLA-B*57, HLA-DRB1*11, and HLA-DRB1*13 were identified for the first time in the literature associated with SARS-CoV-2 infection in kidney transplant recipients.