Chronic rejection: insights from a novel immunosuppressive-free model of kidney transplantation

The use of immunosuppressive drugs in models of chronic rejection may limit their usefulness for mechanistic studies. We have developed a new minor histocompatibility-mismatched rat kidney transplant model without the need for immunosuppression. Kidneys from LEW (RT1(l)) donors were transplanted to congenic WF.1L (RT1(l)) recipients and compared with the reversed strain combination and isogenic controls. Urinary protein excretion was measured serially in all recipients; kidneys were harvested 90, 120, and 180 d after transplantation for morphologic analysis and cytokine gene expression. In vitro lymphocytic reactivity and cytokine analysis of mixed lymphocyte reaction (MLR) culture supernatants by ELISA was also carried out. LEW into WF.1L kidney grafts developed proteinuria starting 120 d after transplantation and were associated with morphologic changes of focal segmental glomerulosclerosis together with interstitial cell infiltrates, upregulated gene expression of IL-1beta, IL-2, and TNF-alpha/-beta, as well as IL-2, IFN-gamma, and TNF-alpha production by lymphocytes in MLR culture supernatants. WF.1L kidneys transplanted into LEW recipients did not develop chronic rejection and had upregulation of Th2 cytokines, both within the allograft and in MLR supernatant of recipient lymphocytes cultured with WF.1L cells. Furthermore, these lymphocytes produced both Th1 and Th2 cytokines when cultured with WF cells, unlike lymphocytes from the LEW isografts, which produced Th1 cytokines when challenged with WF cells. These studies show that indirect allorecognition can cause strain-dependent chronic rejection associated with Th1-like cytokine production, whereas production of Th2 cytokines is associated with protection from the development of chronic rejection.     

Major bile duct injuries after laparoscopic cholecystectomy: A tertiary center experience

Bile duct injury is a severe and potentially life-threatening complication of laparoscopic cholecystectomy. Several series have described a 0.5% to 1.4% incidence of bile duct injuries during laparoscopic cholecystectomy. The aim of this study was to report on an institutional experience with the management of complex bile duct injuries and outcome after surgical repair. Data were collected prospectively from 40 patients with bile duct injuries referred for surgical treatment to our center between April {dy1998} and December 2003. Prior to referral, 35 patients (87.5%) underwent attempts at surgical reconstruction at the primary hospital. In77.5%of the patients, complex typeE1or typeE2BDIwas found. Concomitant with bile duct injury, seven patients had vascular injuries. Roux-en-Y hepaticojejunostomy was carried out in 33 patients. In two patients, Roux-en-Y hepaticojejunostomy and vascular reconstruction were necessary. Five patients, one with primary nondiagnosed Klatskin tumor, required right hepatectomy. Two patients, both with bile duct injuries and vascular damage, died postoperatively. Because of progressive liver insufficiency, one of them was listed for high-urgency liver transplantation but died prior to intervention. At the median follow-up of 589 days, 82.5% of the patients are in excellent general condition. Seven patients have signs of chronic cholangitis. Major bile duct injuries remain a significant cause of morbidity and even death after laparoscopic cholecystectomy. Because they present a considerable surgical challenge, early referral to an experienced hepatobiliary center is recommended.     

Loss-of-function mutations in cathepsin C in two families with Papillon-Lefèvre syndrome are associated with deficiency of serine proteinases in PMNs

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disease that involves severe periodontitis and hyperkeratosis of the hand palms and foot soles. Recently it was found that PLS patients carry loss-of-function mutations in the gene encoding cathepsin C (CTSC). In the present study we have analyzed the CTSC gene in two unrelated families with PLS. In the first non-consanguineous family, mutation analysis revealed the previously reported c.815G>C/p.R272P mutation. The second consanguineous family displayed a c.1213C>A mutation which resulted in the novel mutation p.H405N and is the first mutation described in the active site of the enzyme. The PLS patients had, next to the absence of cathepsin C activity in polymorphonuclear leukocytes (PMNs), no activity of the three serine proteinases elastase, cathepsin G and proteinase 3. Serine proteinases are supposed to be important in both the innate and adaptive immune systems. Their absence in PLS patients could explain the inadequate defense to periodontal infection.     

Chromosomal instability and marker chromosome evolution in oral squamous cell carcinoma

Squamous cell carcinoma of the head and neck and its subset, oral squamous cell carcinoma (OSCC), arise through a multistep process of genetic alterations as a result of exposure to environmental agents, such as tobacco smoke, alcoholic beverages, and viruses, including human papillomavirus. We and others have shown that the karyotypes of OSCC are near-triploid and contain multiple structural and numerical abnormalities. However, despite a background of clonal chromosomal aberrations, individual cells within a culture express many nonclonal numerical and structural abnormalities, termed chromosomal instability (CIN). To evaluate CIN in oral cancer cells, we isolated clones from two OSCC cell lines and carried out classical cytogenetic analysis, fluorescence in situ hybridization using centromere-specific probes, and spectral karyotyping. We observed variation in chromosome number within clones and between clones of the same cell line. Although similar numbers of centromeric signals for a particular chromosome were present, "homologs" of a chromosome varied structurally from cell to cell (marker chromosome evolution) as documented by classical and spectral karyotyping. In addition to the numerical chromosome variations within a clone, we observed marker chromosome evolution by structural chromosome alterations. It appears that both intrinsic structural alterations and extrinsic cytoskeletal factors influence chromosome segregation, resulting in individual tumor cells that express unique karyotypes. We show that CIN and marker chromosome evolution are essential acquired features of neoplastic cells. Proliferation of this heterogeneous cell population may provide some cells with the ability to evade standard therapies.     

Prenatal diagnosis of fetal trisomy 6 mosaicism and phenotype of the affected newborn

The first case of a fetal trisomy 6 mosaicism proven at 25 weeks of gestation by analysis of fetal urine cells is described. Chromosomal analysis was indicated by an ultrasonographically diagnosed heart defect at 21 weeks of gestation. The chromosomal aberration was detected in amniotic fluid cells while fetal blood cells showed a normal chromosome set. At term a boy with normal growth parameter was born. In addition to the expected heart defect, malformations of hands and feet were present.     

Absence of simian virus 40 DNA sequences in primary central nervous system lymphoma in HIV-negative patients

Simian virus 40 (SV40) is known to induce primary brain tumors and lymphomas in animal models. Recently, it was also associated with the pathogenesis of human non-Hodgkins lymphomas. In the present study, we investigated primary central nervous system lymphomas (PCNSL), a defined subgroup of diffuse large B-cell lymphoma confined to the central nervous system, for the presence of SV40 DNA. Frozen tissue samples of 23 PCNSL derived from human immunodeficiency virus-negative patients were analyzed by two different, fully nested polymerase chain reaction protocols. SV40 DNA sequences could not be detected in any of these samples. Thus, SV40 can be added to the list of viruses that have already been excluded as pathogenetically relevant cofactors in PCNSL.     

Is there a specific polysomnographic sleep pattern in children with attention deficit/hyperactivity disorder?

The aim of the study was to characterize the sleep pattern in children with attention deficit/hyperactivity disorder (ADHD). By means of polysomnography (PSG), sleep patterns were studied in 17 unmedicated preadolescent boys rigorously diagnosed with ADHD and 17 control boys precisely matched for age and intelligence. Although ADHD children did not display a general sleep alteration, major PSG data showed a significant increase in the duration of the absolute rapid eye movement (REM) sleep and the number of sleep cycles in ADHD group when compared with controls. In addition, REM sleep latency tended to be shorter in ADHD children. These results suggest that in ADHD children, a forced REM sleep initiation may produce a higher incidence of sleep cycles and may also contribute to an increased duration of the absolute REM sleep. The overall pattern of the findings implies that a forced ultradian cycling appears characteristic for the sleep in ADHD children, which may be related to alterations of brain monoamines and cortical inhibitory control accompanying the ADHD psychopathology.