Lambert-Eaton myasthenic syndrome associated with alemtuzumab administration.

BACKGROUND: Alemtuzumab administration is known to cause secondary autoimmune disease but has not been associated with the development of neurologic autoimmune conditions. Lambert-Eaton myasthenic syndrome (LEMS) is caused by autoantibodies directed against calcium channels on the neuromuscular junction. CASE REPORT: We report a case of a patient with relapsing-remitting multiple sclerosis (RRMS) treated with alemtuzumab who develop generalized weakness initially attributed to progression of MS but eventually determined to be due to LEMS. CONCLUSION: Alemtuzumab treatment can result in the development of neurologic autoimmune conditions that could mimic MS progression.

Myt3 suppression sensitizes islet cells to high glucose-induced cell death via Bim induction.

Diabetes is a chronic disease that results from the body's inability to properly control circulating blood glucose levels. The loss of glucose homoeostasis can arise from a loss of ß-cell mass because of immune-cell-mediated attack, as in type 1 diabetes, and/or from dysfunction of individual ß-cells (in conjunction with target organ insulin resistance), as in type 2 diabetes. A better understanding of the transcriptional pathways regulating islet-cell survival is of great importance for the development of therapeutic strategies that target ß-cells for diabetes. To this end, we previously identified the transcription factor Myt3 as a pro-survival factor in islets following acute suppression of Myt3 in vitro. To determine the effects of Myt3 suppression on islet-cell survival in vivo, we used an adenovirus to express an shRNA targeting Myt3 in syngeneic optimal and marginal mass islet transplants, and demonstrate that suppression of Myt3 impairs the function of marginal mass grafts. Analysis of grafts 5 weeks post-transplant revealed that grafts transduced with the shMyt3 adenovirus contained ~20% the number of transduced cells as grafts transduced with a control adenovirus. In fact, increased apoptosis and significant cell loss in the shMyt3-transduced grafts was evident after only 5 days, suggesting that Myt3 suppression sensitizes islet cells to stresses present in the early post-transplant period. Specifically, we find that Myt3 suppression sensitizes islet cells to high glucose-induced cell death via upregulation of the pro-apoptotic Bcl2 family member Bim. Taken together these data suggest that Myt3 may be an important link between glucotoxic and immune signalling pathways.

Psychosocial Predictors of Mortality Following Lung Transplantation.

Lung transplantation has become an increasingly common treatment for patients with end-stage lung disease. Few studies have examined psychosocial risk factors for mortality in transplant recipients, despite evidence suggesting that elevated levels of negative affect are associated with greater mortality following major cardiac surgery. We therefore examined the relationship between negative affect early after lung transplantation and long-term survival in a sample of 132 lung transplant recipients (28 cystic fibrosis, 64 chronic obstructive pulmonary disease, 26 idiopathic pulmonary fibrosis, 14 other) followed for up to 13.5 years (median 7.4 years) following transplantation. Patients underwent both medical and psychosocial assessments 6 months following transplantation, which included the Beck Depression Inventory-II (BDI-II), Spielberger Anxiety Inventory, and General Health Questionnaire (GHQ). Over the course of follow-up, 80 (61%) participants died. Controlling for demographic factors, native lung disease, disease severity, family income, education level, social support, and frequency of posttransplant rejection, elevated symptoms of depression (BDI-II: HR = 1.31, p = 0.011) and distress (GHQ: HR = 1.28, p = 0.003) were associated with increased mortality. Higher levels of depression and general distress, but not anxiety, measured 6 months following lung transplantation are associated with increased mortality, independent of background characteristics and medical predictors.

Phosphorylation of Atg5 by the Gadd45ß-MEKK4-p38 pathway inhibits autophagy.

Autophagy is a lysosomal degradation pathway important for cellular homeostasis, mammalian development, cancer and immunity. Many molecular components of autophagy have been identified, but little is known about regulatory mechanisms controlling their effector functions. Here, we show that, in contrast to other p38 MAP kinase activators, the growth arrest and DNA damage 45 beta (Gadd45ß)-MAPK/ERK kinase kinase 4 (MEKK4) pathway specifically directs p38 to autophagosomes. This process results in an accumulation of autophagosomes through p38-mediated inhibition of lysosome fusion. Conversely, autophagic flux is increased in p38-deficient fibroblasts and Gadd45ß-deficient cells. We further identified the underlying mechanism and demonstrate that phosphorylation of the autophagy regulator autophagy-related (Atg)5 at threonine 75 through p38 is responsible for inhibition of starvation-induced autophagy. Thus, we show for the first time that Atg5 activity is controlled by phosphorylation and, moreover, that the spatial regulation of p38 by Gadd45ß/MEKK4 negatively regulates the autophagic process.

Identification and analysis of murine pancreatic islet enhancers.

AIMS/HYPOTHESIS: The paucity of information on the epigenetic barriers that are blocking reprogramming protocols, and on what makes a beta cell unique, has hampered efforts to develop novel beta cell sources. Here, we aimed to identify enhancers in pancreatic islets, to understand their developmental ontologies, and to identify enhancers unique to islets to increase our understanding of islet-specific gene expression. METHODS: We combined H3K4me1-based nucleosome predictions with pancreatic and duodenal homeobox 1 (PDX1), neurogenic differentiation 1 (NEUROD1), v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MAFA) and forkhead box A2 (FOXA2) occupancy data to identify enhancers in mouse islets. RESULTS: We identified 22,223 putative enhancer loci in in vivo mouse islets. Our validation experiments suggest that nearly half of these loci are active in regulating islet gene expression, with the remaining regions probably poised for activity. We showed that these loci have at least nine developmental ontologies, and that islet enhancers predominately acquire H3K4me1 during differentiation. We next discriminated 1,799 enhancers unique to islets and showed that these islet-specific enhancers have reduced association with annotated genes, and identified a subset that are instead associated with novel islet-specific long non-coding RNAs (lncRNAs). CONCLUSIONS/INTERPRETATIONS: Our results indicate that genes with islet-specific expression and function tend to have enhancers devoid of histone methylation marks or, less often, that are bivalent or repressed, in embryonic stem cells and liver. Further, we identify a subset of enhancers unique to islets that are associated with novel islet-specific genes and lncRNAs. We anticipate that these data will facilitate the development of novel sources of functional beta cell mass.

Changes in neurocognitive functioning following lung transplantation.

Although neurocognitive impairment is relatively common among patients with advanced lung disease, little is known regarding changes in neurocognition following lung transplantation. We therefore administered 10 tests of neurocognitive functioning before and 6 months following lung transplantation and sought to identify predictors of change. Among the 49 study participants, native diseases included chronic obstructive pulmonary disease (n = 22), cystic fibrosis (n = 12), nonfibrotic diseases (n = 11) and other (n = 4). Although composite measures of executive function and verbal memory scores were generally within normal limits both before and after lung transplantation, verbal memory performance was slightly better posttransplant compared to baseline (p < 0.0001). Executive function scores improved in younger patients but worsened in older patients (p = 0.03). A minority subset of patients (29%) exhibited significant cognitive decline (i.e. >1 standard deviations on at least 20% of tests) from baseline to posttransplant. Patients who declined were older (p < 0.004) and tended to be less educated (p = 0.07). Lung transplantation, like cardiac revascularization procedures, appears to be associated with cognitive decline in a subset of older patients, which could impact daily functioning posttransplant.

Paracrine signalling loops in adult human and mouse pancreatic islets: netrins modulate beta cell apoptosis signalling via dependence receptors.

AIMS/HYPOTHESIS: Adult pancreatic islets contain multiple cell types that produce and secrete well characterised hormones, including insulin, glucagon and somatostatin. Although it is increasingly apparent that islets release and respond to more secreted factors than previously thought, systematic analyses are lacking. We therefore sought to identify potential autocrine and/or paracrine islet growth factor loops, and to characterise the function of the netrin family of islet-secreted factors and their receptors, which have been previously unreported in adult islets. METHODS: Gene expression databases, islet-specific tag sequencing libraries and microarray datasets of FACS purified beta cells were used to compile a list of secreted factors and receptors present in mouse or human islets. Netrins and their receptors were further assessed using RT-PCR, Western blot analysis and immunofluorescence staining. The roles of netrin-1 and netrin-4 in beta cell function, apoptosis and proliferation were also examined. RESULTS: We identified 233 secreted factors and 234 secreted factor receptors in islets. The presence of netrins and their receptors was further confirmed. Downregulation of caspase-3 activation was observed when MIN6 cells were exposed to exogenous netrin-1 and netrin-4 under hyperglycaemic conditions. Reduction in caspase-3 cleavage was linked to the decrease in dependence receptors, neogenin and unc-5 homologue A, as well as the activation of Akt and extracellular signal-regulated protein kinase (ERK) signalling. CONCLUSIONS/INTERPRETATION: Our results highlight the large number of potential islet growth factors and point to a context-dependent pro-survival role for netrins in adult beta cells. Since diabetes results from a deficiency in functional beta cell mass, these studies are important steps towards developing novel therapies to improve beta cell survival.

Apoptotic signaling by c-MYC.

c-MYC has a pivotal function in growth control, differentiation and apoptosis, and its abnormal expression is associated with many tumors. Overexpression of c-MYC sensitizes cells to apoptosis by a variety of stimuli. The decision of a cell to undergo apoptosis and how this apoptotic response is regulated by c-MYC depends on the specific cell type and the physiological status of the cell. Multiple cooperating molecular pathways of cell survival and apoptosis determine whether a cell lives or dies, and understanding how c-MYC interfaces with these pathways to influence the survival of cells is important to understand normal and abnormal development, tumor initiation and progression, and response of tumors to different treatment regimens. This article will provide an overview of the function of the tumor suppressor gene product p53 in the c-MYC-mediated apoptotic response and how c-MYC amplifies the intrinsic mitochondrial pathway and triggers and/or amplifies the death receptor pathways. Finally, a model for how deregulated c-MYC prematurely triggers the normal apoptotic response associated with terminal myeloid differentiation while also blocking the differentiation program is presented.

Leukemia suppressor function of Egr-1 is dependent on transforming oncogene.

We have shown that deregulated expression of either c-Myb or E2F-1 blocks terminal differentiation of M1 myeloid leukemia cells at the blast stage, whereas deregulated c-Myc blocks differentiation at the intermediate stage. Each of these oncogenes potentiates M1 leukemia in vivo. The zinc-finger transcription factor Egr-1 abrogates the block in M1 terminal differentiation imparted by oncogenic c-Myc or E2F-1, suppressing their leukemia-promoting function in nude mice. In this study, we asked whether Egr-1 also abrogates the block in terminal differentiation and suppresses leukemia imparted by deregulated c-Myb. Interestingly, the ectopic expression of Egr-1 in M1 cells expressing deregulated c-Myb only partially abrogated the block in terminal differentiation and did not suppress the leukemic phenotype. Two important implications from these data are that the leukemia suppressor function of Egr-1 is not directly related to how early the transforming oncogene blocks the differentiation program and that the tumor suppressor function of Egr-1 is dependent on the specific oncogene. Egr-1 is dominant to c-Myc- and E2F-1-, but not to c-Myb-, driven leukemia. These findings extend the notion that the molecular nature of genetic lesions responsible for leukemia determines the effectiveness of any given tumor suppressor.

Egr-1 abrogates the E2F-1 block in terminal myeloid differentiation and suppresses leukemia.

Deregulated growth and blocks in differentiation collaborate in the multistage process of leukemogenesis. Previously, we have shown that ectopic expression of the zinc finger transcription factor Egr-1 in M1 myeloblastic leukemia cells promotes terminal differentiation with interleukin-6 (IL-6). In addition, we have shown that deregulated expression of the oncogene E2F-1 blocks the myeloid terminal differentiation program, resulting in proliferation of immature cells in the presence of IL-6. Here it is shown that the positive regulator of differentiation Egr-1 abrogates the E2F-1-driven block in myeloid terminal differentiation. The M1E2F-1/Egr-1 cells underwent G(0)/G(1) arrest and functional macrophage maturation following treatment with IL-6. Furthermore, Egr-1 diminished the aggressiveness of M1E2F-1 leukemias and abrogated the leukemic potential of IL-6-treated M1E2F-1 cells. Previously, we reported that Egr-1 abrogated the block in terminal myeloid differentiation imparted by deregulated c-myc, which blocks differentiation at a later stage than E2F-1, resulting in cells that have the characteristics of functionally mature macrophages that did not undergo G(0)/G(1) arrest. Taken together, this work extends and highlights the tumor suppressor role of Egr-1, with Egr-1 behaving as a tumor suppressor against two oncogenes, each blocking myeloid differentiation by a different mechanism. These findings suggest that Egr-1 and/or Egr-1 target genes may be useful tools to treat or suppress oncogene-driven hematological malignancies.

Endoscopic ultrasound-guided fine-needle aspiration for diagnosis of solid pseudopapillary tumors of the pancreas: a multicenter experience.

BACKGROUND AND STUDY AIMS: Solid pseudopapillary tumors of the pancreas are rare, low-grade, epithelial neoplasms that are usually discovered incidentally in young women. Distinguishing solid pseudopapillary tumors from other pancreatic tumors, especially pancreatic endocrine tumors, can be challenging. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in this context remains unclear. The purpose of this study was to describe the endoscopic ultrasound features of solid pseudopapillary tumors and the role of EUS-FNA in the preoperative diagnosis of these tumors. PATIENTS AND METHODS: Patients from five tertiary referral centers with surgically confirmed solid pseudopapillary tumors who had undergone preoperative EUS-FNA were included. The endoscopic ultrasound findings, cytologic descriptions, immunostaining results, operative records, surgical pathology, and results of the most recent clinical follow-up were reviewed. RESULTS: A total of 28 patients were identified (four men [14 %], 24 women [86 %], mean age +/- standard deviation [SD] 35 +/- 10 years). Solid pseudopapillary tumors had been found as incidental findings on cross-sectional imaging in 50 % of cases. The mean tumor size +/- SD was 42 +/- 19.5 mm and the majority were located in the pancreatic body and tail. The endoscopic ultrasound report described a well-defined, echo-poor mass in 86 %; the tumors were solid in 14 patients (50 %), mixed solid and cystic in 11 patients (39 %), and cystic in three patients (11 %). A preoperative diagnosis of solid pseudopapillary tumor was made in 21 patients (75 %) on the basis of EUS-FNA cytology. Surgical resection was performed in all cases. Laparoscopic resection was performed in eight of these patients (29 %). CONCLUSIONS: A solid pseudopapillary tumor should be included in the differential diagnosis of any well-demarcated, echo-poor, solid or mixed solid/cystic pancreatic lesion seen during endoscopic ultrasound, particularly in young women. The diagnostic accuracy of EUS-FNA for solid pseudopapillary tumors was 75 % in this study. A definitive preoperative diagnosis can guide the surgical approach in selected cases.

Phosphatidylinositol 3-kinase/Akt signaling mediates interleukin-6 protection against p53-induced apoptosis in M1 myeloid leukemic cells.

M1 myeloid leukemic cells were used to dissect the molecular mechanisms of myeloid cell survival and apoptosis. A salient feature of M1 cells is that they respond to the physiological survival factor interleukin-6 (IL-6), yet lack the tumor suppressor gene p53. Functional wild-type activation of temperature-sensitive p53 protein (p53 val) at permissive temperature in M1-t-p53 cells results in rapid apoptosis, which is blocked by IL-6. How p53 induces M1 apoptosis and how IL-6 protects against p53-induced apoptosis are not fully understood. Here it is shown that p53-mediated apoptosis of M1 cells involves rapid activation of the proapoptotic Fas/CD95 death pathway, which activates caspases 8 and 10. Functional p53 also targets the mitochondria, causing upregulation of proapoptotic Bax, downregulation of prosurvival Bcl-2 and activation of caspase 9. IL-6 was found to protect against p53-induced apoptosis via activation of the PI3K/Akt survival pathway, which in turn counters both the Fas/CD95 and mitochondrial apoptotic pathways and activates the prosurvival transcription factor nuclear factor-kappaB (NF-kappaB). Taken together, this work supports a novel model for leukemic progression where cells that acquire the ability to produce an autocrine survival factor, such as IL-6, can bypass normal p53 surveillance function by targeting Akt, which in turn can exert effects on the regulators of apoptosis, such as the Fas/CD95 pathway, the mitochondria and NF-kappaB.

Training facilities in gastrointestinal endoscopy: an animal model as an aid to learning endoscopic ultrasound.

Apart from dedicated fellowships, endoscopic ultrasound (EUS) training comprises "informal" methods, including EUS courses and the use of animal models. We have tried to determine the usefulness of a "hands-on" experience with a live animal model as a teaching strategy for EUS training. In 1997 and 2000 the American Society for Gastrointestinal Endoscopy (ASGE) sponsored hands-on EUS workshops using a live porcine model and participants in these courses were asked to complete a questionnaire about the course (2 years after the 1997 workshop and immediately after the 2000 workshop). The main outcome measurements were the usefulness and quality of the overall course and of the hands-on component in particular, and the effect on EUS practice patterns. Twenty of 38 attendees (53 %) responded to the survey administered 2 years after the 1997 course: 95 % thought the overall course was useful and 85 % valued the hands-on portion; 60 % of respondents had either started performing EUS or, if already experienced in EUS, had increased the number of EUS examinations and/or the complexity of EUS procedures they performed. Of the 34 participants who were at the 2000 ASGE course, over 90 % thought that the course enhanced their EUS skills and 88 % believed that they would be likely to perform EUS in the future. The study was limited in that it did not account for other methods of EUS training that could affect EUS practice patterns and also by the fact that not all the 1997 course participants responded to the questionnaire. In conclusion, live animal models may be a useful adjuctive method for learning EUS skills for the novice or the less experienced endosonographer.

Hematopoietic cells from gadd45a-deficient and gadd45b-deficient mice exhibit impaired stress responses to acute stimulation with cytokines, myeloablation and inflammation.

The gadd45 family of gene(s) is rapidly induced by genotoxic stress or by differentiation-inducing cytokines. Using bone marrow (BM) from gadd45a-/-, gadd45b-/- and wild-type (wt) mice, we investigated their role in stress responses of myeloid cells to acute stimulation with differentiating cytokines, myelotoxic agents and inflammatory substances. Bone marrow cells from gadd45a-/- and gadd45b-/- mice displayed compromised myeloid differentiation and higher apoptosis in vitro, following acute stimulation with a variety of differentiating cytokines. Intriguingly, gadd45a-/- and gadd45b-/- colony forming units granulocyte/macrophage progenitors displayed prolonged proliferation capacity compared to wt controls upon re-plating in methylcellulose supplemented with interleukin-3. The recovery of the BM myeloid compartment following 5-Fluorouracil-induced myelo-ablation was much slower in gadd45a-/- and gadd45b-/- mice compared to wt controls. Furthermore, the response of myeloid cells to inflammatory stress, inflicted via intraperitoneal administration of sodium caseinate was impaired in gadd45a-/- and gadd45b-/- mice compared to age-matched wt mice, as indicated by lower percentage of Gr-1-positive cells in the BM and lower number of myeloid cells in peritoneal exudates. Overall, these data indicate that both gadd45a and gadd45b play a role in modulating physiological stress responses of myeloid cells to acute stimulation with differentiating cytokines, myelo-ablation and inflammation. These findings should aid in understanding the response of normal and malignant hematopoietic cells to physiological and chemical stressors including anticancer agents.

Identification of novel genes and transcription factors involved in spleen, thymus and immunological development and function.

We constructed and analyzed six serial analysis of gene expression (SAGE) libraries to identify genes with previously uncharacterized roles in spleen or thymus development. A total of 625 070 tags were sequenced from the three spleen (embryonic day (E)15.5, E16.5 and adult) and three thymus (E15.5, E18.5 and adult) libraries. These tags corresponded to 83 182 tag types, which mapped unambiguously to 36 133 different genes. Genes over-represented in these libraries, compared to 115 mouse SAGE libraries (www.mouseatlas.org), included genes of known and unknown immunological or developmental relevance. The expression profiles of 11 genes with unknown roles in spleen and thymus development were validated using reverse transcription-qPCR. We further characterized the expression of one of these candidates, RIKEN cDNA 9230105E10 that encodes a murine homolog of Trim5alpha, in numerous adult tissues and immune cell types. In addition, we demonstrate that transcript levels are upregulated in response to TLR stimulation of plasmacytoid dendritic cells and macrophages. This work provides the first evidence of regulated and cell type-specific expression of this gene. In addition, these observations suggest that the SAGE libraries provide an important resource for further investigations into the molecular mechanisms regulating spleen and thymus organogenesis, as well as the development of immunological competence.

Is endosonography guided fine needle aspiration (EUS-FNA) for sarcoidosis as good as we think?

BACKGROUND: Preliminary data show that endosonography guided fine needle aspiration (EUS-FNA) may be an accurate method for diagnosing sarcoidosis. However, these data were obtained in a small selected group of patients with a very high pretest probability of sarcoidosis. This retrospective study reports on the use of EUS-FNA in an unselected group of patients with mediastinal lymphadenopathy of unknown origin. METHODS: The EUS database of a single tertiary referral centre was reviewed for patients who underwent EUS-FNA for mediastinal lymphadenopathy of unknown origin. Clinical presentation and imaging studies of each case were carefully reviewed and the diagnosis "sarcoidosis" or "no sarcoidosis" attributed if possible. The diagnoses were compared with the result of EUS-FNA. RESULTS: One hundred and twenty four patients were investigated. In 35 cases EUS-FNA identified granulomas (group 1); in the other 89 cases (group 2) no granulomas were detected. The definite diagnoses in group 1 were sarcoidosis (n = 25), indefinite (n = 7), no sarcoidosis (n = 3). The definite diagnoses in group 2 were sarcoidosis (n = 3), indefinite (n = 9), no sarcoidosis (n = 77). Of the 77 cases with no sarcoidosis, 44 were diagnosed with other diseases. The other 33 showed non-specific changes in the FNA and sarcoidosis was excluded by negative non-EUS pathology (n = 17) and clinical presentation. The sensitivity and specificity for EUS-FNA were 89% (95% CI 82 to 94) and 96% (95% CI 91 to 98), respectively, after exclusion of the indefinite cases in both groups. CONCLUSIONS: EUS-FNA is an accurate method for diagnosing sarcoidosis in an unselected group of patients with mediastinal lymphadenopathy. The reported sensitivity and specificity must be appreciated in the context of the difficult and often incomplete clinical diagnosis of sarcoidosis.

Endoscopic ultrasonography in the diagnosis and staging of neoplasms of the head and neck.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a minimally invasive and highly accurate method of detecting mediastinal lymph-node metastases in gastrointestinal and lung cancer. Little information is available regarding the use of EUS-FNA to stage tumors in the head and neck region. This study reports experience with EUS in the diagnosis and staging of these tumors and their mediastinal spread. PATIENTS AND METHODS: The records of patients who underwent EUS for diagnosis and/or staging of head and neck tumors were reviewed. Referral criteria were suspected invasion of the esophagus by a lower-neck mass on cervical computed tomography (CT) or magnetic resonance imaging (MRI), or mediastinal lymphadenopathy > 10 mm on a chest CT. RESULTS: Thirty-two patients (23 men, nine women; mean age 65 years, range 44 - 80) were referred and underwent 35 EUS examinations. In one patient, EUS was not possible due to a benign esophageal stricture. In 17 patients with suspected esophageal invasion on CT scans, EUS demonstrated invasion of the esophagus in four cases and of the pleura in one; 12 tumors showed no visible invasion of adjacent structures. The other 17 examinations were carried out for suspected mediastinal metastatic disease. In eight cases, EUS-FNA confirmed metastatic disease, whereas only benign changes were shown in the other nine cases. EUS-FNA also provided the first tissue diagnosis in two primary tumors and identified malignancy in one patient with no CT suspicion of positive mediastinal lymph nodes. EUS avoided the need for more invasive investigations in all patients with mediastinal lymphadenopathy, and it changed the management in 12 of the 17 patients (71 %) with suspected esophageal invasion and in eight of the 17 patients (47 %) with suspected mediastinal disease. CONCLUSIONS: EUS with FNA provides a viable approach to the diagnosis and staging of tumors in the head and neck region when there is a suggestion of esophageal invasion on CT or MRI, or enlarged mediastinal lymph nodes. EUS with FNA may avoid the need for mediastinoscopy or other more invasive techniques for staging of these neoplasms.

Comparison of EUS-guided 19-gauge Trucut needle biopsy with EUS-guided fine-needle aspiration.

BACKGROUND AND STUDY AIMS: The accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) depends on immediate specimen review by a cytopathologist. Stromal tumors, lymphoma, and well-differentiated pancreatic cancer are difficult to diagnose on the basis of cytology alone. To overcome these limitations, a 19-gauge Trucut needle has been developed to obtain histological samples at EUS. This pilot study compares the specimen adequacy and diagnostic accuracy of EUS-guided Trucut needle biopsy (EUS-TNB) with EUS-FNA. PATIENTS AND METHODS: A total of 18 patients underwent EUS-TNB and EUS-FNA. The specimen adequacy and diagnostic accuracy of the two techniques was compared. The technical performance and safety profile of the Trucut needle were also evaluated. RESULTS: The EUS-TNB specimen was adequate for evaluation in 15/18 patients compared with 18/18 with EUS-FNA (83 % vs. 100 %, not significant). The diagnostic accuracy of EUS-TNB was not significantly different from EUS-FNA (78 % vs. 89 %). Two complications were encountered: one patient developed mediastinitis and required surgery; another had immediate bleeding that was managed conservatively. One technical problem was encountered: the Trucut needle failed to deploy after two passes when a gastric stromal cell tumor was being biopsied. CONCLUSION: The diagnostic accuracy of the new EUS-TNB is comparable to that of EUS-FNA. In our experience, the overall efficacy and safety profile of the Trucut needle appears modest.

Acivicin-induced alterations in renal and hepatic glutathione concentrations and in gamma-glutamyltransferase activities.

gamma-Glutamyltransferase (gamma-GT) catalyzes the hydrolysis of glutathione, glutathione S-conjugates, and gamma-substituted l-glutamate derivatives. Acivicin is an irreversible inhibitor of gamma-GT that has been used to study the role of gamma-GT in glutathione homeostasis and glutathione-dependent bioactivation reactions. The present studies were undertaken because of reported conflicting effects of acivicin on the nephrotoxicity of some haloalkenes that undergo glutathione-dependent bioactivation. The objective of this study was to test the hypothesis that acivicin may alter renal glutathione concentrations; acivicin-induced changes in renal glutathione concentrations may alter the susceptibility of the kidney to the nephrotoxic effects of haloalkenes. Hence, diurnal and acivicin-induced changes in renal and hepatic glutathione concentrations along with renal and hepatic gamma-GT activities were investigated. The previously observed diurnal variations in hepatic glutathione concentrations in fed rats were confirmed, but no diurnal variations were observed in renal glutathione concentrations or in renal or hepatic gamma-GT activities. Renal and hepatic glutathione concentrations and gamma-GT activities were measured in tissue homogenates from rats given 0, 0.1, or 0.2 mmol acivicin/kg (i.p.) and killed 0, 2, 4, 8, 12, or 24 hr later. Renal glutathione concentrations were increased above control values in acivicin-treated rats, whereas acivicin had no effect on hepatic glutathione concentrations. Renal gamma-GT activities decreased within 2 hr after giving acivicin and remained decreased for 24 hr. Acivicin had no effect on hepatic gamma-GT activities, except at 24 hr after treatment when values in acivicin-treated rats were elevated compared with controls. Although the present studies do not afford an explanation of the mechanism whereby acivicin increases the nephrotoxicity of some haloalkenes, they do indicate that acivicin is not a reliable probe to investigate the role of gamma-GT in haloalkene-induced nephrotoxicity.