Transcriptome Profiling of a Salt Excluder Hybrid Grapevine Rootstock 'Ruggeri' throughout Salinity

Salinity is one of the substantial threats to plant productivity and could be escorted by other stresses such as heat and drought. It impairs critical biological processes, such as photosynthesis, energy, and water/nutrient acquisition, ultimately leading to cell death when stress intensity becomes uncured. Therefore, plants deploy several proper processes to overcome such hostile circumstances. Grapevine is one of the most important crops worldwide that is relatively salt-tolerant and preferentially cultivated in hot and semi-arid areas. One of the most applicable strategies for sustainable viticulture is using salt-tolerant rootstock such as Ruggeri (RUG). The rootstock showed efficient capacity of photosynthesis, ROS detoxification, and carbohydrate accumulation under salinity. The current study utilized the transcriptome profiling approach to identify the molecular events of RUG throughout a regime of salt stress followed by a recovery procedure. The data showed progressive changes in the transcriptome profiling throughout salinity, underpinning the involvement of a large number of genes in transcriptional reprogramming during stress. Our results established a considerable enrichment of the biological process GO-terms related to salinity adaptation, such as signaling, hormones, photosynthesis, carbohydrates, and ROS homeostasis. Among the battery of molecular/cellular responses launched upon salinity, ROS homeostasis plays the central role of salt adaptation.

Physiological Comparison of Two Salt-Excluder Hybrid Grapevine Rootstocks under Salinity Reveals Different Adaptation Qualities

Like other plant stresses, salinity is a central agricultural problem, mainly in arid or semi-arid regions. Therefore, salt-adapted plants have evolved several adaptation strategies to counteract salt-related events, such as photosynthesis inhibition, metabolic toxicity, and reactive oxygen species (ROS) formation. European grapes are usually grafted onto salt-tolerant rootstocks as a cultivation practice to alleviate salinity-dependent damage. In the current study, two grape rootstocks, 140 Ruggeri (RUG) and Millardet et de Grasset 420A (MGT), were utilized to evaluate the diversity of their salinity adaptation strategies. The results showed that RUG is able to maintain higher levels of the photosynthetic pigments (Chl-T, Chl-a, and Chl-b) under salt stress, and hence accumulates higher levels of total soluble sugars (TSS), monosaccharides, and disaccharides compared with the MGT rootstock. Moreover, it was revealed that the RUG rootstock maintains and/or increases the enzymatic activities of catalase, GPX, and SOD under salinity, giving it a more efficient ROS detoxification machinery under stress.

A recessive mutation in muscadine grapes causes berry color-loss without influencing anthocyanin pathway

Anthocyanins, a major class of flavonoids, are important pigments of grape berries. Despite the recent discovery of the genetic cause underlying the loss of color, the metabolomic and molecular responses are unknown. Anthocyanin quantification among diverse berry color muscadines suggests that all genotypes could produce adequate anthocyanin quantities, irrespective of berry color. Transcriptome profiling of contrasting color muscadine genotypes proposes a potential deficiency that occurs within the anthocyanin transport and/or degradation mechanisms and might cause unpigmented berries. Genome-wide association studies highlighted a region on chromosome-4, comprising several genes encoding glutathione S-transferases involved in anthocyanin transport. Sequence comparison among genotypes reveals the presence of two GST4b alleles that differ by substituting the conserved amino acid residue Pro₁₇₁-to-Leu. Molecular dynamics simulations demonstrate that GST4b2–Leu₁₇₁ encodes an inactive protein due to modifications within the H-binding site. Population genotyping suggests the recessive inheritance of the unpigmented trait with a GST4b2/2 homozygous. A model defining colorless muscadines’ response to the mutation stimulus, avoiding the impact of trapped anthocyanins within the cytoplasm is established.

Transcriptome profiling and mutational analysis suggest a potential deficiency in anthocyanin transport by glutathione S-transferases and/or degradation mechanisms that might cause unpigmented berries.

Chromosome-level genome sequence assembly and genome-wide association study of Muscadinia rotundifolia reveal the genetics of 12 berry-related traits

Vitis has two subgenera: Euvitis, which includes commercially important Vitis vinifera and interspecific hybrid cultivars, and Muscadinia. Of note, the market for Muscadinia grapes remains small, and only Muscadinia rotundifolia is cultivated as a commercial crop. To establish a basis for the study of Muscadinia species, we generated chromosome-level whole-genome sequences of Muscadinia rotundifolia cv. Noble. A total of 393.8 Mb of sequences were assembled from 20 haploid chromosomes, and 26 394 coding genes were identified from the sequences. Comparative analysis with the genome sequence of V. vinifera revealed a smaller size of the M. rotundifolia genome but highly conserved gene synteny. A genome-wide association study of 12 Muscadinia berry-related traits was performed among 356 individuals from breeding populations of M. rotundifolia. For the transferability of markers between Euvitis and Muscadinia, we used 2000 core genome rhAmpSeq markers developed to allow marker transferability across Euvitis species. A total of 1599 (80%) rhAmpSeq markers returned data in Muscadinia. From the GWAS analyses, we identified a total of 52 quantitative trait nucleotides (QTNs) associated with the 12 berry-related traits. The transferable markers enabled the direct comparison of the QTNs with previously reported results. The whole-genome sequences along with the GWAS results provide a new basis for the extensive study of Muscadinia species.

Diversity in blueberry genotypes and developmental stages enables discrepancy in the bioactive compounds, metabolites, and cytotoxicity

Eight blueberry cultivars at three developmental stages were investigated for metabolite profiling, antioxidant, and anticancer activities. Cultivars- and developmental stages-variations were determined in total phenolic, flavonoid, DPPH, and FRAP antioxidant assays. The anticancer capacity was equal against A549, HepG2, and Caco-2 cancer cells, whereas the inhibition rate was dose-, incubation period-, cultivar-, and developmental stages-dependent. The untargeted metabolite profiling by UPLC-TOF-MS analysis of two contrast cultivars, 'Vernon' and 'Star', throughout the developmental stages revealed 328 metabolites; the majority of them were amino acids, organic acids, and flavonoids. The multivariate statistical analysis identified five metabolites, including quinic acid, methyl succinic acid, chlorogenic acid, oxoadipic acid, and malic acid, with positively higher correlations with all anticancer activities. This comprehensive database of blueberry metabolites along with anticancer activities could be targeted as natural anticancer potentials. This study would be of great value for food, nutraceutical, and pharmaceutical industries as well as plant biotechnologists.

Determination of Fertility-Related Traits in Muscadine Grape Population

In this study, fertility-related traits of 90 muscadine grape genotypes were evaluated. Selected genotypes included 21 standard cultivars, 60 breeding lines, and nine Vitis × Muscadinia hybrids (VM hybrids). The first fruiting bud (FFB), bud fertility (BF), bud fertility coefficient (BFC), number of flowers/flower cluster (N.F/FC), fruit-set efficiency (FSE), number of clusters/vine (N.C/V), and yield/vine (Y/V) traits were evaluated. The FFB trait did not show significant differences among genotypes. The muscadine genotype O28-4-2-2 (1.6 ± 0.2) displayed the FFB closest to the base; however, O17-16-2-1, O18-2-1, and VM A12-10-2 genotypes had the most distant FFB (3.6 ± 0.3). All the other fertility-related traits varied widely among the population. The BF, BFC, N.F/FC, FSE, N.C/V, and Y/V exhibited a range estimated at 35.1%, 81.5%, 259.7, 63.3%, 177 C/V, and 22.3 kg/V, respectively. The muscadine genotypes O42-3-1 (36.7% ± 1.3) and Majesty (34% ± 1.2) exhibited the highest BF; however, the VM A12-10-2 (1.6% ± 0.1) recorded the lowest BF. The VM genotype O15-16-1 (82.8% ± 4.1) displayed the highest BFC; however, the VM A12-10-2 (1.3% ± 0.1) showed the lowest BFC. The muscadine genotypes D7-1-1 (280.3 F/FC ± 21.7) and O17-17-1 (20.7 F/FC ± 5.5) showed the highest and lowest N.F/FC, respectively. The maximum and minimum FSE was observed for the Rosa cultivar (65.7% ± 2.4) and muscadine genotype D7-1-1 (2.4% ± 0.2), respectively. The minimum N.C/V was recorded for VM genotype A12-10-2 (6 C/V ± 0.2) and maximum noted for muscadine genotypes B20-18-2 (183 C/V ± 7.5) and O44-14-1 (176 C/V ± 7.3). Muscadine genotype O23-11-2 (22.6 kg ± 1.1) produced the highest Y/V; however, the lowest yield was recorded for O15-17-1, Fry Seedless, Sugargate, and the VM genotypes and A12-10-2, with an average yield among them estimated at 0.4 kg ± 0.2.

Untargeted Metabolomics and Antioxidant Capacities of Muscadine Grape Genotypes during Berry Development

Three muscadine grape genotypes (Muscadinia rotundifolia (Michx.) Small) were evaluated for their metabolite profiling and antioxidant activities at different berry developmental stages. A total of 329 metabolites were identified using UPLC-TOF-MS analysis (Ultimate 3000LC combined with Q Exactive MS and screened with ESI-MS) in muscadine genotypes throughout different developmental stages. Untargeted metabolomics study revealed the dominant chemical groups as amino acids, organic acids, sugars, and phenolics. Principal component analysis indicated that developmental stages rather than genotypes could explain the variations among the metabolic profiles of muscadine berries. For instance, catechin, epicatechin-3-gallate, and gallic acid were more accumulated in ripening seeds (RIP-S). However, tartaric acid and malonic acid were more abundant during the fruit-set (FS) stage, and malic acid was more abundant in the veraison (V) stage. The variable importance in the projection (VIP > 0.5) in partial least-squares–discriminant analysis described 27 biomarker compounds, representing the muscadine berry metabolome profiles. A heatmap of Pearson’s correlation analysis between the 27 biomarker compounds and antioxidant activities was able to identify nine antioxidant determinants; among them, gallic acid, 4-acetamidobutanoic acid, trehalose, catechine, and epicatechin-3-gallate displayed the highest correlations with different types of antioxidant activities. For instance, DPPH and FRAP conferred a similar antioxidant activity pattern and were highly correlated with gallic acid and 4-acetamidobutanoic acid. This comprehensive study of the metabolomics and antioxidant activities of muscadine berries at different developmental stages is of great reference value for the plant, food, pharmaceutical, and nutraceutical sectors.

Biometrics Assessment of Cluster- and Berry-Related Traits of Muscadine Grape Population

In this study, biometrics assessment of flower structure, cluster-, and berry-related traits were evaluated in a population of 90 muscadine grape genotypes for three consecutive years. This population consisted of 21 standard cultivars, 60 breeding lines, and 9 Vitis x Muscadinia hybrids (VM hybrids). Cluster length (CL) and width (CWI) characteristics exhibited slight differences among the population, with a range estimated at 7.1 and 4.6 cm, respectively. However, cluster weight (CWE), number of berries/cluster (N.B/C), and cluster compactness (CC) traits showed more diversity between individuals with a calculated range of 205.6 g, 32.6 B/C, and 24.1, respectively. Interestingly, all berry-related traits greatly varied between individuals, excluding the number of seeds/berry (N.S/B) character. The N.S/B trait displayed a narrow range of 5.6 seeds within the population. However, characters of berry length (BL), width (BWI), weight (BWE), the weight of seeds/berry (W.S/B), firmness (FF), and dry scar pattern (SP) demonstrated a wide estimated range of 21.2 mm, 21.7 mm, 25.4 g, 0.71 g, 0.21 N, and 82%, respectively. Normal distribution analysis for each trait suggested different distribution patterns extended between unimodal to multimodal behavior. Hierarchical mapping analysis was able to classify the population into several clades based on physical cluster- and berry-related attributes. The PCA suggested that hermaphroditic (perfect) flower structure is associated with compact clusters exhibiting small berries in size and weight (i.e., muscadine genotypes suitable for wine production). However, female flower structure is associated with clusters displaying large berries in size and weight (i.e., muscadine genotypes appropriate for fresh consumption). These patterns occurred independently of cluster size and weight characters. This research is the first study evaluating muscadine biometrics characters at a population level, providing valuable information for market demand and muscadine breeding programs.

Evaluation of Biochemical Juice Attributes and Color-Related Traits in Muscadine Grape Population

Biochemical juice attributes and color-related traits of muscadine grape genotypes have been investigated. For this study, 90 muscadine genotypes, including 21 standard cultivars, 60 breeding lines, and 9 Vitis x Muscadinia hybrids (VM), were evaluated. The biochemical properties of total soluble solids (TSS), titratable acidity, and TSS/Acid (T/A) ratio showed modest diversity among genotypes with a range of 10.3 °Brix, 2.1 mg tartaric acid/L, and 4.6, respectively. Nonetheless, the pH trait exhibited a tight range of 0.74 among the population with a minimum and maximum pH of 3.11 ± 0.12 and 3.85 ± 0.12. Color-related traits showed more deviation between individuals. Total anthocyanin content (TAC), luminosity index (L*), hue angle (h°), and chroma index (C*) displayed a range of 398 µg/g DW, 33.2, 352.1, and 24, respectively. The hierarchical clustering map classified the population into two large groups of colored and non-colored grapes based on L* and h°, suggesting the predominance of these two characters among the population. The colored berries genotypes clade was further divided into several sub-clades depending on C*, TAC, and TSS levels. The principal component analysis (PCA) separated the four-color characteristics into two groups with a negative correlation between them, L* and C* versus TAC and h°. Further, PCA suggested the positive influence of acidity in enhancing the different nutraceutical components. Despite the nature of anthocyanins as a member of phenolic compounds, a lack of significant correlation between TAC and nutraceutical-related traits was detected. The dissimilatory matrix analysis highlighted the muscadine individuals C11-2-2, E16-9-1, O21-13-1, and Noble as particular genotypes among the population due to enhanced color characteristics.

Transcriptome Profiling During Muscadine Berry Development Reveals the Dynamic of Polyphenols Metabolism

Muscadine grapes accumulate higher amounts of bioactive phenolics compared with other grape species. To identify the molecular events associated with polyphenolic accumulation that influence antioxidant capacity, two contrasting muscadine genotypes (C5 and C6) with varied phenolic/flavonoid content and antioxidant activity were investigated via RNA-sequencing during berry development. The results showed that berry development is concomitant with transcriptome profile changes, which was more pronounced at the véraison (V) stage. Despite that the downregulation pattern of gene expression dominated the upregulation through berry development, the C5 genotype maintained higher expression levels. Comparative transcript profiling allowed the identification of 94 differentially expressed genes with potential relevance in regulating fruit secondary metabolism, including 18 transcription factors and 76 structural genes. The genes underlying the critical enzymes in the modification reactions of polyphenolics biosynthetic pathway, including hydroxylation, methylation, and glycosylation were more pronounced during the immature stages of prevéraison (PrV), V, and postvéraison (PoV) in the C5 genotype, resulting in more accumulation of biologically active phenolic/flavonoid derivatives. The results suggested that muscadine grapes, as in bunch grapes (Vitis sp.); possess a similar mechanism that organizes polyphenolics accumulation; however, the set of total flavonoids (TFs) and structural genes coordinating the pathway varies between the two species.

On the Breakage of High Aspect Ratio Crystals in Filter Beds under Continuous Percolation

Purpose

This work details experimental observations on the effect of liquid flow percolating through packed beds of crystals to elucidate how the filtration pressure severely alters the size distribution and crystal shape. Pressure filtration is widely used in the pharmaceutical industry, and frequently results in undesired size distribution changes that hinder further processing.

Methods

The percolation methodology presented fixes fluid flow through a bed of crystals, resulting in a pressure over the bed. X-ray computed tomography (XCT) provided detailed observations of the bed structure. Detailed 2D particle size data was obtained using automated microscopy and was analysed using an in-house developed tool.

Results

Crystal breakage is observed when the applied pressure exceeds a critical pressure: 0.5–1 bar for ibuprofen, 1–2 bar for β-L glutamic acid (LGA) and 2–2.5 bar for para amino benzoic acid (PABA). X-ray computed tomography showed significant changes in bed density under the applied pressure. Size analysis and microscope observations showed two modes of breakage: (i) snapping of long crystals and (ii) shattering of crystals.

Conclusion

LGA and PABA have a similar breakage strength (50 MPa), ibuprofen is significantly weaker (9 MPa). Available breakage strength data may be correlated to the volumetric Gibbs free energy. Data from 12 and 35 mm bed diameters compares well to literature data in a 80 mm filter; the smaller, easy to operate percolation unit is a versatile tool to assess crystal breakage in filtration operations.

Electronic supplementary material

The online version of this article (10.1007/s11095-020-02958-x) contains supplementary material, which is available to authorized users.

3D characterisation of dry powder inhaler formulations: Developing X-ray micro computed tomography approaches

Carrier-based dry powder inhaler (DPI) formulations need to be accurately characterised for their particle size distributions, surface roughnesses, fines contents and flow properties. Understanding the micro-structure of the powder formulation is crucial, yet current characterisation methods give incomplete information. Commonly used techniques like laser diffraction (LD) and optical microscopy (OM) are limited due to the assumption of sphericity and can give variable results depending on particle orientation and dispersion. The aim of this work was to develop new three dimensional (3D) powder analytical techniques using X-ray computed tomography (XCT) that could be employed for non-destructive metrology of inhaled formulations. α-lactose monohydrate powders with different characteristics have been analysed, and their size and shape (sphericity/aspect ratio) distributions compared with results from LD and OM. The three techniques were shown to produce comparable size distributions, while the different shape distributions from XCT and OM highlight the difference between 2D and 3D imaging. The effect of micro-structure on flowability was also analysed through 3D measurements of void volume and tap density. This study has demonstrated for the first time that XCT provides an invaluable, non-destructive and analytical approach to obtain number- and volume-based particle size distributions of DPI formulations in 3D space, and for unique 3D characterisation of powder micro-structure.

Severe disease presentation and poor outcomes among pediatric systemic lupus erythematosus patients in South Africa

Background Systemic lupus erythematosus (SLE) is a life-threatening multisystem autoimmune disease that is more severe in patients of African ancestry and children, yet pediatric SLE on the African continent has been understudied. This study describes a cohort of pediatric SLE (PULSE) patients in South Africa. Methods Patients with a diagnosis of SLE (1997 American College of Rheumatology criteria) diagnosed prior to age 19 years in Cape Town, South Africa, were enrolled in this cross-sectional study from September 2013 to December 2014. Information on clinical and serological characteristics was extracted from medical records. Results were compared to a well-described North American pediatric SLE cohort. Results Seventy-two South African patients were enrolled in the study; mean age 11.5 years; 82% were girls. The racial distribution was 68% Coloured, 24% Black, 5% White and 3% Asian/Indian. Most patients presented with severe lupus nephritis documented by renal biopsy (61%). Of patients with lupus nephritis, 63% presented with International Society of Nephrology/Renal Pathology Society class III or IV. Patients in the PULSE cohort were more likely to be treated with cyclophosphamide, methotrexate and azathioprine. The PULSE cohort had high disease activity at diagnosis (mean Systemic Lupus Erythematosus Disease Activity Index-2K (SLEDAI-2K) 20.6). The SLEDAI-2K at enrolment in the PULSE cohort (5.0) did not differ from the North American pediatric SLE cohort (4.8). Sixty-three per cent of the PULSE cohort had end organ damage with Systemic Lupus International Collaborating Clinics Damage Index (SLICC-DI) score >0 (mean SLICC-DI 1.9), compared to 23% in a previously reported US cohort. Within the PULSE cohort, nine (13%) developed end-stage renal disease with six (8%) requiring transplant, strikingly higher than North American peers (transplant rate <1%). Conclusions The PULSE cohort had highly active multiorgan disease at diagnosis and significant disease damage at enrolment in the South African registry. South African patients have severe lupus nephritis and poor renal outcomes compared to North American peers. Our study revealed a severe disease phenotype in the PULSE cohort resulting in poor outcomes in this high-risk population.

Liver transplantation at Red Cross War Memorial Children's Hospital

The liver transplant programme for infants and children at Red Cross War Memorial Children's Hospital is the only established paediatric service in sub-Saharan Africa. Referrals for liver transplant assessment come from most provinces within South Africa as well as neighbouring countries.

PATIENTS AND METHODS

Since 1987, 81 children (range 6 months-14 years) have had 84 liver transplants with biliary atresia being the most frequent diagnosis. The indications for transplantation include biliary atresia (48), metabolic (7), fulminant hepatic failure (10), redo transplants (3) and other (16). Four combined liver/kidney transplants have been performed. Fifty-three were reduced-size transplants with donor/recipient weight ratios ranging from 2:1 to 11:1 and 32 children weighed less than 10 kg.

RESULTS

Sixty patients (74%) survived 3 months-14 years post-transplant. Overall cumulative 1- and 5-year patient survival figures are 79% and 70% respectively. However, with the introduction of prophylactic intravenous ganciclovir and the exclusion of hepatitis B virus (HBV) IgG core Ab-positive donors, the 1-year patient survival is 90% and the projected 5-year paediatric survival is > 80%. Early (< 1 month) post-liver-transplant mortality was low. Causes include primary malfunction (1), inferior vena cava thrombosis (1), bleeding oesophageal ulcer (1), sepsis (1) and cerebral oedema (1). Late morbidity and mortality was mainly due to infections: de novo hepatitis B (5 patients, 2 deaths), Epstein-Barr virus (EBV)- related post-transplantation lymphoproliferative disease (12 patients, 7 deaths) and cytomegalovirus (CMV) disease (10 patients, 5 deaths). Tuberculosis (TB) treatment in 3 patients was complicated by chronic rejection (1) and TB-drug-induced subfulminant liver failure (1).

CONCLUSION

Despite limited resources, a successful paediatric programme has been established with good patient and graft survival figures and excellent quality of life. Shortage of donors because of infection with HBV and human immunodeficiency virus (HIV) leads to significant waiting-list mortality and infrequent transplantation.

Overview of a paediatric renal transplant programme

INTRODUCTION

Renal transplantation is the therapy of choice for children with end-stage renal failure. There are many challenges associated with a paediatric programme in a developing country where organs are limited.

METHODS

A retrospective review was undertaken of 149 paediatric renal transplants performed between 1968 and 2006 with specific emphasis on transplants performed in the last 10 years. Survival of patients and grafts was analysed and specific problems related to drugs and infections were reviewed.

RESULTS

On review of the total programme, 60% of the transplants have been performed in the last 10 years, with satisfactory overall patient and graft survival for the first 8 years post transplant. At this point, transfer to adult units with non-compliance becomes a significant problem. Rejection is less of a problem than previously but infection is now a bigger issue--specifically tuberculosis (TB), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections with related complications. A wide variety of drugs are available for tailoring immunosuppression to minimise side-effects.

CONCLUSION

It is possible to have a successful paediatric transplant programme in a developing country. However, to improve long-term outcomes certain issues need to be addressed, including reduction of nephrotoxic drugs and cardiovascular risk factors and providing successful adolescent to adult unit transition.

Nephrotoxic Effects of Immunosuppressant Therapy in Pediatric Liver Transplant Recipients

Drugs used for immunosuppression have been implicated in causing numerous long-term side effects including nephrotoxicity, glucose intolerance, and hyperlipidemia. In this study, we reviewed our pediatric liver transplant recipients in terms of glomerular filtration rate (GFR) as well as fasting glucose and lipid profiles. To date, 79 pediatric liver transplantations have been performed at our center: 24 transplantations of at least 5 months to a maximum of 7.3 years posttransplant are reviewed herein. The mean time posttransplantation was 2.1 years. Nine boys and 15 girls showed a distribution of 19 mixed race, 3 black, and 2 white patients. The mean age at the time of transplantation was 6.6 years (0.8-13.3 years) with 8 cases under the age of 3 years. All recipients started with Cyclosporine Neoral (CSA) as first line, but, at the time of testing, immunosuppression included 5 children on CSA and 19 on Tacrolimus. Radionuclide 51 Cr-EDTA Glomerular Filtration Rates (GFR) showed a range from 21 to 220 mL/min/1.73 m2 (mean 96.1, median 89.8). Seven cases had a GFR less than 75 mL/min/1.73 m2. Twenty-one children were on antihypertensives agents: 15 children on 1 agent and 6 children on 2 agents. On full fasting lipid profiles, the total cholesterol ranged from 2 to 7.9 mmol/L (mean 4.4). Only 1 child is currently on statin therapy. Fasting glucose ranged from 3.2 to 5.9 mmol/L (mean 4.1) No difference was observed in glucose values between CsA and Tacrolimus. Thus, immunosuppressive therapies, such as the calcineurin inhibitors, are known to cause nephrotoxicity, which is of concern in pediatric liver transplant recipients. Almost all our patients currently require antihypertensive therapy. At present, the renal function is adequate in the majority of the group, but this study needs to be extended to other pediatric liver transplant recipients with particular emphasis on those who are more than 5 years posttransplantation.