Effect of Extending the Original Eligibility Criteria for the CROSS Neoadjuvant Chemoradiotherapy on Toxicity and Survival in Esophageal Cancer.

BACKGROUND: Patients with curable esophageal cancer (EC) who proceed beyond the original Chemoradiotherapy for Oesophageal Cancer Followed by Surgery Study (CROSS) eligibility criteria are also treated with neoadjuvant chemoradiotherapy (nCRT). This study assessed the effect that extending the CROSS eligibility criteria for nCRT has on treatment-related toxicity and overall survival (OS) in EC. METHODS: The study enrolled 161 patients with locally advanced EC (T1N1-3/T2-4aN0-3/M0) treated with the CROSS schedule followed by esophagectomy. Group 1 consisted of 89 patients who met the CROSS criteria, and group 2 consisted of 72 patients who met the extended eligibility criteria, i.e. a tumor length greater than 8 cm (n = 24), more than 10% weight loss (n = 35), more than 2-4 cm extension in the stomach (n = 21), celiac lymph node metastasis (n = 13), and/or age over 75 years (n = 2). The study assessed the differences in nCRT-associated toxicity [National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE) grade ≥ 3] and 90-day postoperative mortality. Moreover, the prognostic value for OS was assessed with multivariate Cox regression analysis. RESULTS: No difference was found in nCRT-associated toxicity (P = 0.117), postoperative complications (P = 0.783), and 90-day mortality (P = 0.492). The OS differed significantly (P = 0.004), with a median of 37.3 months [95% confidence interval (CI), 10.4-64.2 months] for group 1 and 17.2 months (95% CI 13.8-20.7 months) for group 2. Pathologic N stage (P = 0.023), pathologic T stage (P = 0.043), and group 2 (P = 0.008) were independent prognostic factors for OS. CONCLUSIONS: Extension of the CROSS study eligibility criteria for nCRT did not affect nCRT-associated toxicity, postoperative complications, and postoperative mortality, but was prognostic for OS.

Diagnosis of early pancreas graft failure via antibody-mediated rejection: single-center experience with 256 pancreas transplantations.

Early pancreas graft loss is usually attributed to technical failure while the possibility of antibody-mediated rejection (AMR) is generally overlooked. To investigate the role of AMR in early pancreas graft loss, we retrospectively assessed 256 patients with simultaneous pancreas-kidney transplantation (SPK) between 1985 and 2010 at our institute. We included 33 SPK patients who lost their pancreas graft <1 year after transplantation. AMR was diagnosed based on donor-specific antibodies, C4d and histology in 7 cases, 8 cases were suspicious for AMR and 18 pancreas graft losses were not due to AMR. Acute AMR occurred >1 month after transplantation in 6/7 cases, whereas all other causes typically led to loss <1 month after transplantation. Thrombotic lesions occurred equally among the 33 cases. In 12/18 concurrent kidney specimens, the diagnostic results paralleled those of the pancreas graft. All patients with acute AMR of the pancreas graft lost their renal grafts <1 year after transplantation. In the setting of a thrombotic event, histopathological analysis of early pancreas graft loss is advisable to rule out the possibility of AMR, particularly because a diagnosis of acute AMR has important consequences for renal graft outcomes.

Glycogen synthase 1 targeting reveals a metabolic vulnerability in triple-negative breast cancer.

BACKGROUND: Hypoxia-induced glycogen turnover is implicated in cancer proliferation and therapy resistance. Triple-negative breast cancers (TNBCs), characterized by a hypoxic tumor microenvironment, respond poorly to therapy. We studied the expression of glycogen synthase 1 (GYS1), the key regulator of glycogenesis, and other glycogen-related enzymes in primary tumors of patients with breast cancer and evaluated the impact of GYS1 downregulation in preclinical models. METHODS: mRNA expression of GYS1 and other glycogen-related enzymes in primary breast tumors and the correlation with patient survival were studied in the METABRIC dataset (n = 1904). Immunohistochemical staining of GYS1 and glycogen was performed on a tissue microarray of primary breast cancers (n = 337). In four breast cancer cell lines and a mouse xenograft model of triple-negative breast cancer, GYS1 was downregulated using small-interfering or stably expressed short-hairpin RNAs to study the effect of downregulation on breast cancer cell proliferation, glycogen content and sensitivity to various metabolically targeted drugs. RESULTS: High GYS1 mRNA expression was associated with poor patient overall survival (HR 1.20, P = 0.009), especially in the TNBC subgroup (HR 1.52, P = 0.014). Immunohistochemical GYS1 expression in primary breast tumors was highest in TNBCs (median H-score 80, IQR 53-121) and other Ki67-high tumors (median H-score 85, IQR 57-124) (P < 0.0001). Knockdown of GYS1 impaired proliferation of breast cancer cells, depleted glycogen stores and delayed growth of MDA-MB-231 xenografts. Knockdown of GYS1 made breast cancer cells more vulnerable to inhibition of mitochondrial proteostasis. CONCLUSIONS: Our findings highlight GYS1 as potential therapeutic target in breast cancer, especially in TNBC and other highly proliferative subsets.

Genetic associations in diabetic nephropathy: a meta-analysis.

AIMS/HYPOTHESIS: This meta-analysis assessed the pooled effect of each genetic variant reproducibly associated with diabetic nephropathy. METHODS: PubMed, EMBASE and Web of Science were searched for articles assessing the association between genes and diabetic nephropathy. All genetic variants statistically associated with diabetic nephropathy in an initial study, then independently reproduced in at least one additional study, were selected. Subsequently, all studies assessing these variants were included. The association between these variants and diabetic nephropathy (defined as macroalbuminuria/proteinuria or end-stage renal disease [ESRD]) was calculated at the allele level and the main measure of effect was a pooled odds ratio. Pre-specified subgroup analyses were performed, stratifying for type 1/type 2 diabetes mellitus, proteinuria/ESRD and ethnic group. RESULTS: The literature search yielded 3,455 citations, of which 671 were genetic association studies investigating diabetic nephropathy. We identified 34 replicated genetic variants. Of these, 21 remained significantly associated with diabetic nephropathy in a random-effects meta-analysis. These variants were in or near the following genes: ACE, AKR1B1 (two variants), APOC1, APOE, EPO, NOS3 (two variants), HSPG2, VEGFA, FRMD3 (two variants), CARS (two variants), UNC13B, CPVL and CHN2, and GREM1, plus four variants not near genes. The odds ratios of associated genetic variants ranged from 0.48 to 1.70. Additional variants were detected in subgroup analyses: ELMO1 (Asians), CCR5 (Asians) and CNDP1 (type 2 diabetes). CONCLUSIONS/INTERPRETATION: This meta-analysis found 24 genetic variants associated with diabetic nephropathy. The relative contribution and relevance of the identified genes in the pathogenesis of diabetic nephropathy should be the focus of future studies.

Therapeutic potential of vasopressin V2 receptor antagonist in a mouse model for autosomal dominant polycystic kidney disease: optimal timing and dosing of the drug.

BACKGROUND: The renoprotective effect of vasopressin V2 receptor antagonist (V2RA) is currently being tested in a clinical trial in early autosomal dominant polycystic kidney disease (ADPKD). If efficacious, this warrants life-long treatment with V2RA, however, with associated side effects as polydipsia and polyuria. We questioned whether we could reduce the side effects without influencing the renoprotective effect by starting the treatment later in the disease or by lowering drug dosage. METHODS: To investigate this, we administered V2RA OPC-31260 at a high (0.1%) and low (0.05%) dose to a tamoxifen-inducible kidney epithelium-specific Pkd1-deletion mouse model starting treatment at Day 21 (early) or 42 (advanced). After 3 and 6 weeks of treatment, we monitored physiologic and potential renoprotective effects. RESULTS: Initiation of V2RA treatment at advanced stage of the disease lacked renoprotective effects and had less pronounced physiologic effects than early initiation. After 3 weeks on a high dose, cyst ratio and kidney weight were reduced versus untreated controls (18 versus 25%, P = 0.05, and 0.33 versus 0.45 g, P = 0.03, respectively). After 6 weeks of treatment, however, this did not reach significance anymore, even at a high dose (cyst ratio 24 versus 27%, P = 0.12, and kidney weight 0.55 versus 0.66 g, P = 0.38). CONCLUSIONS: Our results suggest that intervention with V2RA should be instituted early in ADPKD and that it might be necessary to further increase the dosage of this drug later in the disease to decrease cyst growth.

Pancreas allograft biopsies with positive c4d staining and anti-donor antibodies related to worse outcome for patients.

C4d+ antibody-mediated rejection following pancreas transplantation has not been well characterized. Therefore, we assessed the outcomes of 27 pancreas transplantation patients (28 biopsies), with both C4d staining and donor-specific antibodies (DSA) determined, from a cohort of 257 patients. The median follow-up was 50 (interquartile range [IQR] 8-118) months. Patients were categorized into 3 groups: group 1, patients with minimal or no C4d staining and no DSA (n = 13); group 2, patients with either DSA present but no C4d, diffuse C4d+ and no DSA or focal C4d+ and DSA (n = 6); group 3, patients with diffuse C4d+ staining and DSA (n = 9). Active septal inflammation, acinar inflammation and acinar cell injury/necrosis were significantly more abundant in group 3 than in group 2 (respective p-values: 0.009; 0.033; 0.025) and in group 1 (respective p-values: 0.034; 0.009; 0.002). The overall uncensored pancreas graft survival rate for groups 1, 2 and 3 were 53.3%, 66.7% and 34.6%, respectively (p = 0.044). In conclusion, recipients of pancreas transplants with no C4d or DSA had excellent long-term graft survival in comparison with patients with both C4d+ and DSA present. Hence, C4d should be used as an additional marker in combination with DSA in the evaluation of pancreas transplant biopsies.

Rational use of 18F-FDG PET/CT in patients with advanced cutaneous melanoma: A systematic review.

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is increasingly used in patients with advanced melanoma. Immune checkpoint inhibitors and BRAF/MEK-targeted therapy have transformed the therapeutic landscape of metastatic melanoma. Consequently, a need for markers predicting (early) response to treatment and for monitoring treatment (toxicity) has arisen. This systematic review appraises the current literature evidence for rational use of 18F-FDG PET/CT scans in staging, clinical decision-making, treatment monitoring and follow-up in advanced melanoma. 18F-FDG PET/CT has high overall accuracy for detection of distant metastases and is, combined with cerebral MRI, the preferred imaging strategy for staging metastatic melanoma. In contrast, strong evidence supporting the standard use of 18F-FDG PET/CT for predicting and monitoring therapy response and toxicity is currently lacking. Essential for determining the position of 18F-FDG PET/CT during treatment course in advanced melanoma are well-designed studies with standardized scanning protocols, incorporation of clinical parameters and comparison with contrast-enhanced CT alone.

Early renal ischemia-reperfusion injury in humans is dominated by IL-6 release from the allograft.

The pathophysiology of ischemia/reperfusion (I/R) injury is complex, and current knowledge of I/R injury in humans is incomplete. In the present study, human living-donor kidney transplantation was used as a highly reproducible model to systematically study various processes potentially involved in early I/R injury. Unique, direct measurements of arteriovenous concentration differences over the kidney revealed massive release of interleukin (IL)-6 in the first 30 minutes of graft reperfusion and a modest release of IL-8. Among the assessed markers of oxidative and nitrosative stress, only 15(S)-8-iso-PGF(2alpha) was released. When assessing cell activation, release of prothrombin factor 1 + 2 indicated thrombocyte activation, whereas there was no release of markers for endothelial activation or neutrophil activation. Common complement activation complex sC5b-9 was not released into the bloodstream, but was released into urine rapidly after reperfusion. To investigate whether IL-6 plays a modulating role in I/R injury, a mouse experiment of renal I/R injury was performed. Neutralizing anti-IL-6 antibody treatment considerably worsened kidney function. In conclusion, this study shows that renal I/R in humans is dominated by local IL-6 release. Neutralization of IL-6 in mice resulted in a significant aggravation of renal I/R injury.

GMP-17-positive T-lymphocytes in renal tubules predict progression in early stages of IgA nephropathy.

Treatment of patients with IgA nephropathy (IgAN) depends on a reliable assessment of disease progression based on measurements of glomerular filtration rate (GFR), proteinuria, hypertension, and tubulointerstitial changes. We sought to determine whether progression could be predicted from analysis of glomerular and tubulointerstitial inflammation in biopsies taken at an early stage of IgAN. We retrospectively analyzed biopsies from 50 patients, relating the subsequent clinical course to infiltration with B- and T-lymphocytes, granule membrane protein of 17 kDa (GMP-17) positive cytotoxic T cells, macrophages, fibroblasts, and tubulointerstitial expression of human leukocyte antigen-D related (HLA-DR). At biopsy, 19 patients had decreased GFR while 13 of 31 patients with normal GFR and progressive IgAN differed significantly from 18 non-progressors in the level of proteinuria and in the severity of scores for mesangial proliferation, tubular atrophy, interstitial fibrosis, and interstitial infiltrates. On multivariate regression analysis these differences disappeared; however, associations with GMP-17-positive cytotoxic T-lymphocytes in intact renal tubules and of B-lymphocytes in the interstitium remained significant. Our study may have identified a marker of disease progression in early stages of IgAN.

Reflection contrast microscopy: The bridge between light and electron microscopy.

Reflection contrast microscopy (RCM) is a light microscopic method to image cells at high definition and enhanced sensitivity compared to conventional bright-field microscopy. RCM images have very high contrast, which makes them easily applicable for digital image analysis. Because ultrathin sections are mostly used in this method, RCM also functions by bridging light with electron microscopy: the combination of ultrastructural with histochemical studies. RCM can also replace electron microscopy for rapid and simple screening of large quantities of samples for immunocytochemical staining. Special attention is paid to small biological objects, which have to be processed for RCM. If you encounter the limits of brightfield microscopy, in resolution, sensitivity or handling of the specimen, RCM will be a feasible option. Reflection contrast microscopy methods use only slightly adjusted electron microscopy methods for specimen preparation. Therefore, many familiar techniques for ultrathin specimen preparation can be applied. It is essential that only refractive index differences exist in those areas that are of interest and that the further specimen is as optically homogenic as possible, with a refractive index as close to that of glass as possible. Therefore, plastic embedding is recommended.

Sex specific association between carnosinase gene CNDP1 and cardiovascular mortality in patients with type 2 diabetes (ZODIAC-22).

INTRODUCTION: Homozygosity for a 5-leucine repeat (5L-5L) in the carnosinase gene (CNDP1) has been associated with a reduced prevalence of diabetic nephropathy in cross-sectional studies in patients with type 2 diabetes, particularly in women. Prospective studies on mortality are not available. This study investigated whether 5L-5L was associated with mortality and progression of renal function loss and to what extent this effect is modified by sex. METHODS: In a prospective cohort of patients with type 2 diabetes, a Cox proportional hazard model was used to compare 5L-5L with other genotypes regarding (cardiovascular) mortality. Renal function slopes were obtained by within-individual linear regression of the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) equation, and were compared between 5L-5L and other genotypes. RESULTS: 871 patients were included (38% with 5L-5L). After 9.5 years of follow-up, hazards ratios (HR) for all-cause and cardiovascular mortality in 5L-5L versus other genotypes were 1.09 [95% confidence interval (CI) 0.88-1.36] and 1.12 (95% CI 0.79-1.58), respectively. There was a significant interaction between CNDP1 and sex for the association with cardiovascular mortality (p = 0.01), not for all-cause mortality (p = 0.32). Adjusted HR in 5L-5L for cardiovascular mortality was 0.69 (95% CI 0.39-1.23) in men and 1.77 (95% CI 1.12-2.81) in women. The slopes of eGFR-MDRD did not significantly differ between 5L-5L and other genotypes. CONCLUSIONS: The association between CNDP1 and cardiovascular mortality was sex-specific, with a higher risk in women with 5L-5L genotype. CNDP1 was not associated with all-cause mortality or change in eGFR.

Segmental distribution of the endocytosis receptor gp330 in renal proximal tubules.

The subcellular distribution and segmental variations in location of gp330, a scavenger receptor for filtered proteins in renal proximal tubules, was analyzed. Kidney tissue from rats (4 different strains), rabbits and humans were analyzed by light- and electron microscope immunocytochemistry, using cryosections or Lowicryl sections from cryosubstituted tissue. Gp330 was located mainly in apical coated pits, small and large endocytic vacuoles and in dense apical tubules in the proximal tubule cells. The labeling density was markedly higher in segments 1 and 2 as compared to segment 3 of the proximal tubule. In addition to the location in the early part of the endocytic pathway, gp330 was also present in lysosomes, especially in segments 1 and 2. The lysosomal labeling was not restricted to the membrane, but was also seen in the matrix. Localization of gp330 in lysosomes was confirmed on sections from purified lysosomal fractions from rat renal cortex. The brush border localization of gp330 in proximal tubules exhibited a characteristic segmental variation. In the initial part of segment 1, there was virtually no brush border labeling. In the remaining part of segment 1 and in segment 2, there was a distinct but sometimes patchy labeling of the brush border. In segment 3, groups of microvilli of approximately 10 as seen in sections were intensively labeled from bottom to tip and there were often more than one of these groups on a single cell, the remaining microvilli were unlabeled. No differences in the cellular and subcellular localization of gp330 were observed between species or rat strains. In conclusion, the present study demonstrates that in addition to its location in the early endocytic and recycling pathway, gp330 is also present in microvilli and the protein and degradation products thereof is present in lysosomes, consistent with its role as a protein scavenger receptor.

Distribution of renal lesions in idiopathic systemic vasculitis: A three-dimensional analysis of 87 glomeruli.

Extracapillary proliferation and fibrinoid necrosis are the main diagnostic glomerular lesions in renal biopsy specimens of patients with idiopathic systemic vasculitis. Neither the incidence nor the correlation between extracapillary proliferation and fibrinoid necrosis in renal biopsy specimens from patients with systemic vasculitis has been systematically evaluated. By means of a three-dimensional analysis, we made a topographic reconstruction of the distribution of extracapillary proliferation and fibrinoid necrosis in affected glomeruli and tested different biopsy-processing protocols to optimize histopathologic analysis in clinical practice. Paraffin blocks of renal biopsy specimens from six patients diagnosed with systemic vasculitis were completely and serially sectioned in 2-microm thick sections and stained with the Gomori trichrome method. Glomeruli were scored per section for the presence of fibrinoid necrosis and extracapillary proliferation. Subsequently, a three-dimensional reconstruction was obtained for 87 glomeruli. In only one glomerulus did fibrinoid necrosis occur without extracapillary proliferation; in 51%, a combination of the two lesions was found; in 22%, extracapillary proliferation occurred in the absence of fibrinoid necrosis; and 26% did not show either lesion. Using the standard protocol from our department (ie, evaluation of 20 consecutive sections in various stainings), the chance of finding extracapillary proliferation was 100% and that of finding fibrinoid necrosis was 73%. If 5 sections stained with the Gomori trichrome were added, the latter percentage increased to 86%. Using skip-serial sections, even better results (87% to 92%) were obtained, with four skips as the best option (92%). In conclusion, our finding that fibrinoid necrosis rarely occurs in the absence of extracapillary proliferation may imply that both lesions are etiologically related. In addition, our observations indicate that the incidence of fibrinoid necrosis may be underestimated in clinical practice, depending on the number of sections evaluated.

Cell surface antigen phenotypes and enzyme expression patterns of two murine T-cell lymphomas derived from early and/or mature thymus cells.

A number of cell surface markers (T200, ThB, Thy1, Lyt1 and Lyt2 and a glycolipid) and enzymes (ATP-ase, acid phosphatase, beta-glucuronidase, 5'-nucleotidase, non-specific esterase, ANAE and chloroacetate esterase) were determined for two murine T-cell lymphomas: the DBA/2-strain-derived SL2 with a phenotype close to that of a mature thymocyte and the GRS-strain-derived GSRL13 with a phenotype of a more primitive thymocyte. While the pattern of expression of the enzymes was similar for SL2 and GRSL13 and as such indistinguishable from that of the majority of thymus cells, the pattern of cell surface antigen expression was clearly different. GRSL12 cells express the ThB antigen and a glycolipid antigen detectable with monoclonal antibody 30-H11, but not Lyt1 and Lyt2 antigens. SL2 cells, however, do not express ThB and the glycolipid antigen, but do express Lyt1 and Lyt2.

Remodeling of the porcine pulmonary autograft wall in the aortic position.

OBJECTIVE: Dilatation and valve regurgitation are disturbing sequelae of the pulmonary root functioning at systemic pressures. We tried to characterize the histologic mode of adaptation of the neoaortic wall. METHODS: We compared routine histologic studies, immunohistochemical staining, and computer-assisted morphometric analysis of aortic, pulmonary autograft, and native pulmonary wall specimens from pigs in which, as a newborn, a valveless pulmonary autograft had been implanted in the aorta. RESULTS: Histologic examination of the pulmonary autograft revealed a viable, normally revascularized wall without degenerative phenomena. Smooth muscle cells were enlarged and rearranged. The characteristic "pulmonary" medial elastin lamellar structure was retained, which was confirmed by morphometry. Immunohistochemistry of the autograft revealed relatively strong staining of type III collagen and alpha smooth muscle actin, exclusive staining of basic fibroblast growth factor, and no staining of proliferation markers proliferating cell nuclear antigen and Ki67. CONCLUSION: The developing pulmonary autograft in the aortic position becomes normally revascularized, lacks major degenerative phenomena, and retains its own typical pulmonary morphologic features. Remodeling is accomplished by increased extracellular matrix deposition with collagen as an important constituent. The marked expression of growth factors in the autograft suggests the persistence of increased metabolic activity.

Disproportionate enlargement of the pulmonary autograft in the aortic position in the growing pig.

PURPOSE: This study was aimed to demonstrate growth in the pulmonary autograft after transplantation to the aortic position. METHODS AND MATERIALS: In 20 piglets (weight 25.4 +/- 3.5 kg) (mean +/- standard deviation) a Ross operation was performed and in five piglets (weight 9.3 +/- 0.7 kg) (mean +/- standard deviation) the ascending aorta was replaced with a valveless pulmonary autograft. Animals were allowed to grow as much as possible. Postmortem explanted autografts were studied by direct measurements of the valve cusps in the Ross group and of the wall segments in the valveless autograft group. Measurements of the first group were compared with the values of a separate control group, and values of the second group were compared with values of samples taken at operation. RESULTS: In the Ross group, cuspal weight, height, and width increased significantly by comparison with body weight (p < or = 0.003). The rate of increase did not differ significantly from that of the control group with a native pulmonary valve. However, there was a rapid adaptation of the autograft valves resulting in a significantly higher mean cuspal weight, height, and width. In the valveless autograft group, wall circumference, thickness, and height increased significantly (p < or = 0.001). The circumference increased significantly more than that of the native pulmonary wall. Compared with the native aortic wall, the pulmonary autograft media showed retained pulmonary architecture on microscopic study. CONCLUSION: These data suggest that the dimensional increase of the pulmonary autograft in the aortic position in the growing pig is determined by growth and dilatation, that the valve mass increases more than that of the native pulmonary valve, and that the characteristic pulmonary microscopic architecture is retained.

Collagen types VIII and X, two non-fibrillar, short-chain collagens. Structure homologies, functions and involvement in pathology.

Collagens can be divided into two groups, i.e., fibrillar and non-fibrillar collagens. Short-chain collagens, a subgroup of non-fibrillar collagens, comprises collagen type VIII and type X. These two collagen types show several similarities in structure and possibly also in function. Type VIII collagen appears to be secreted by rapidly proliferating cells. It can be found in basement membranes and may serve as a molecular bridge between different types of matrix molecules. In different tissues this collagen type may serve different functions. Stabilization of membranes, angiogenesis, and interactions with other extracellular matrix molecules. Since collagen type X is produced by hypertrophic chondrocytes, this collagen type can only be found in matrix of the hypertrophic zone of the epiphyseal growth plate cartilage. Collagen type X is probably involved in the process of mineralization, endochondral ossification, and is also proposed to play a role in angiogenesis. Collagen types VII and X may be involved in matrix and bone disorders. Their structure, function, and involvement in pathology are discussed in this review.

T cell subsets in immunologically-mediated glomerulonephritis.

Until recently, research on the pathogenesis of glomerulonephritis has been mainly focused on the characterization of humoral immune responses in the initiation of glomerular injury. However, there is a growing recognition that both cellular and humoral immune responses, in varying proportions, are involved in the pathogenesis of immunologically-mediated glomerulonephritis. T lymphocytes are essential cellular elements of cell-mediated immunity. Both in experimental models of immune-mediated renal disease and in histopathological analyses of human nephropathies, the involvement of T cells has been demonstrated in the immunoregulation of nephritogenic immune responses and in the immune injury in the kidney. T cell activation resulting in either delayed-type hypersensitivity, cytolytic reactions, abnormal expression of major histocompatibility complex (MHC) molecules, or B cell activation can result in glomerulonephritis. These different types of responses are exerted by distinct T cell subsets defined by cell surface markers and cytokine profiles. CD4+ T cells in vivo are functionally heterogeneous with respect to cytokine production and the CD45 isoforms that are found on their surface. Like CD4+ T cells, CD8+ T cells may also be heterogeneous at the level of cytokine production. The roles of CD4+ and CD8+ cells and their cytokine profiles in glomerulonephritis have not been extensively investigated yet, but such studies might improve the understanding of the pathogenesis and possibly lead to new therapeutic approaches of human glomerulonephritis. In this review the role of distinct T lymphocyte subsets in experimental and human glomerulonephritis will be discussed.

Tissue chimerism in human cryopreserved homograft valve explants demonstrated by in situ hybridization.

BACKGROUND: The presence of viable cells may contribute to increased homograft valve durability. These cells may be of infiltrating recipient or persisting donor origin. In this study, in situ hybridization was used to assess the origin of cells in cryopreserved homograft valve explants. METHODS: A total of 10 homografts with a donor-recipient gender mismatch were acquired from patients whose graft had been explanted at reoperation or at autopsy. The period of implantation varied from 14 days to 70 months. Frozen sections were made and alternately examined with hematoxylin and eosin staining and in situ hybridization. Male cells were distinguished from female using a biotinylated Y-chromosome-specific deoxyribonucleic acid probe. RESULTS: No endothelial cells were found. Thirty percent of the leaflets showed large acellular zones and 30% were completely acellular. The homograft arterial wall was occupied by a vast majority of penetrating host fibroblasts in 80% of the studied specimens. Donor and recipient cells were coexistent in the wall in 60% of the studied specimens and in 50% of the leaflets. In 30% only host cells could be identified. CONCLUSIONS: This finding of tissue chimerism may lead to new insights in homograft pathology. The technique of in situ hybridization may provide an indispensable contribution in further homograft research.