Analysis of electrical phenomena accompanying the growth of Neurospora crassa hyphae: theory and experiment

To describe electrical phenomena observed in growth of Neurospora crassa hyphae, a theoretical model was developed considering the hypha as a one-dimensional electric cable with non-uniform longitudinal distribution of current sources reflecting the activity of proton pumps. A profile of the density of the pump current along the hypha is proposed, at which the results of simulation quantitatively coincide with the results of physiological experiments. The model values of energy coupling in the growth zones were estimated. The experimental dependence of the elongation rate of regenerating apical hypha fragments on their lengths was determined. Based on the comparison of these experimental results with the results of analysis of the model, the contribution of the axial metabolite transport, from the distal parts of the hypha to the apical part, to the dynamics of the apical cell growth was estimated. The possibility of evaluating the intensity of high-molecular-weight syntheses and/or accumulation of substances in granules was demonstrated. The growth rate of the regenerating hypha fragments was shown to correlate with the electric current flowing into the apical fragment 0.2-mm in length.     

Pancreatic mucinous ductal ectasia and intraductal papillary neoplasms. A single malignant clinicopathologic entity

OBJECTIVE: The purpose of the study is to review a single institutional experience with mucinous ductal ectasia (MDE) and intraductal papillary neoplasms (IPNs) and to compare the clinicopathologic features of the two groups of tumors. SUMMARY BACKGROUND DATA: Mucinous ductal ectasia and IPNs represent newly recognized categories of pancreatic exocrine tumors, previously confused with pancreatic cystic neoplasms. The natural history of MDE and IPN is not well understood, and it is unclear whether MDE and IPN represent two distinct tumors or the same clinicopathologic entity. METHODS: The authors reviewed the clinical presentation, treatment, histopathology, and outcomes of 23 patients diagnosed with MDE or IPN at their institution over the past 6 years. RESULTS: The mean age at presentation for the cohort of patients with MDE and IPN was 62.5 years. The prevalence of abdominal pain was 75%, jaundice 25%, weight loss 42%, steatorrhea 37.5%, diabetes 37.5%, and history of pencreatitis 29%. Serum CA 19-9 levels ranged from 0 to 5350 units/mL with high levels reflecting advanced disease. There were no significant differences between MDE and IPN with respect to these parameters. Both MDE and IPN comprised papillary villous epithelial neoplasms involving the main and large pancreatic ducts. The tumors ranged from a few millimeters in size to panductal and were distinguished easily from cystic neoplasms in all cases. Invasive carcinoma was present in 11 (46%) of 24 patients, carcinoma in situ in an additional 10 (42%) of 24 patients, and low grade dysplasia in the remaining 3 (12%) of 24 patients. Mucinous ductal ectasia and IPN differed histopathologically only in degree of mucin secretion and tumor location. Mucinous ductal ectasia, but not IPN, was characteristically mucin-hypersecreting and more frequently involved the head of the gland than did IPN (11/16 vs. 1/8 p < 0.04). All patients were explored surgically and 20 (83%) of 24 of the tumors were resectable with frozen section control of the duct margins (9 pancreatoduodenectomies, 4 distal pencreatectomies, 7 total pancreatectomies). Despite the 88% prevalence of cancer, the overall survival at a mean follow-up of 21 months was 13 (87%) of 15 for MDE and 5 (71%) of 7 for IPN. CONCLUSIONS: Intraductal papillary neoplasms with or without MDE represent a spectrum of main duct papillary tumors ranging from adenoma to carcinoma with differing amounts of extracellular mucin production. Malignant IPNs with or without MDE typically exhibit extensive intraductal growth but are slow to invade the periductal tissues and slow to metastasize. The majority of patients with these tumors have resectable disease and a favorable prognosis; endoscopic therapy is inappropriate. The encompessing term intraductal papillary-mucinous tumors is appropriate.     

The pharmacokinetics of Kefzol in patients with acute pancreatitis when administered intravenously and endolymphatically

Pharmacokinetics was studied of kefsole administered by intravenous and endolymphatic routes to patients (n = 23) with acute pancreatitis. The studies made showed that intravenous route for the drug administration makes for a quicker entering of the antibiotic into the peritoneal exudate. Apart from these reasons, endolymphatic antibacterial therapy does not appear to avert the development of complications involving pus-formation/discharging in acute pancreatitis and does not seem to be essential in the complex of therapeutic measures to be applied for treating the above patients.     

Discovery of Mitophagy Inhibitors with Therapeutic Potential in Different Familial Amyotrophic Lateral Sclerosis Mutations

Mitophagy is the selective degradation of mitochondria by autophagy. It promotes the turnover of mitochondria and prevents the accumulation of dysfunctional mitochondria, which can lead to cellular degeneration. Mitophagy is known to be altered in several pathological conditions, especially in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). We recently demonstrated an increase in autophagy flux in lymphoblasts from ALS patients bearing a mutation in SOD1. Thus, the identification of mitophagy inhibitors may be a therapeutic option to recover mitochondrial homeostasis. Here, using a phenotypic mitophagy assay, we identified a new mitophagy inhibitor, the small molecule named IGS2.7 from the MBC library. Interestingly, the treatment of different cellular and in vivo models of ALS with mutations on SOD1 and TARDBP with this inhibitor restores autophagy to control levels. These results point mitophagy inhibitors, especially IGS2.7, to a new therapeutic approach for familial ALS patients.     

Complete nucleotide sequence of HTLV-II isolate NRA: comparison of envelope sequence variation of HTLV-II isolates from U.S. blood donors and U.S. and Italian i.v. drug users

Seven cardiac electrophysiology stimulators from four manufacturers (Biotronik, Bloom, Digitimer and Medtronic) in common current use are reviewed. The stimulators differ in the features provided and the design adopted to achieve these features. The number of output channels ranges from one to four, the number of extra-stimuli available ranges from two to six, and these can be delivered as a variety of sequences. Some of the stimulators (Digitimer and Bloom) are modular while others (Biotronik and Medtronic 532 series) are of an integrated design comprising a single physical unit. The design of the Medtronic EP-2 has both integrated and modular characteristics. The features of the stimulators associated with input, output, control and the user interface are specifically reviewed. The features are also compared against the published recommendations of the American Heart Association. In addition, a summary of stimulator user comments from a number of electrophysiology centres is presented. All of the stimulators fulfil, or are close to fulfilling, basic electrophysiological requirements, but some provide more complex facilities such as would be required by specialist centres.     

Evidence that C1q binds specifically to CH2-like immunoglobulin gamma motifs present in the autoantigen calreticulin and interferes with complement activation

Calreticulin (CRT) is located predominantly in the endoplasmic reticulum (ER) of cells, where it functions as a quality control controller of protein folding. However, CRT is also a prevalent autoantigen in patients with systemic lupus erythematosus (SLE), where its release from the cell may arise as a results of dysfunctional apoptosis and inefficient removal of ER vesicles, which are an abundant source of CRT and other autoantigens. Indicative of this is the presence of autoantibodies against CRT in the sera of 40-60% of all SLE patients. Once released into the circulation, CRT might bind directly to C1q and we have suggested that this association may result in a defect in C1q-mediated clearance of antigen-antibody complexes. It has been previously shown that CRT under physiological salt conditions binds to the globular head of C1q. It is known that the globular head region of C1q binds to the CH2 domain in the Fc portion of immunoglobulin gamma (IgG). The N-terminal half of CRT contains a number of short regions of 7-10 amino acids that show sequence similarity to the putative C1q binding region in the CH2 domain of IgG. By use of a series of 92 overlapping CRT synthetic peptides, a number of C1q binding sites on the CRT molecule have been identified, including several containing a CH2-like motif similar to the ExKxKx C1q binding motif found in the CH2 domain of IgG. A number of these peptides were shown to inhibit binding of C1q to IgG and reduce binding of native CRT to C1q. Moreover, several of the peptides were capable of inhibiting the classical pathway of complement activation. These studies have identified specific binding sites on the CRT molecule for C1q and lend support to the hypothesis that interaction of CRT with C1q may interfere with the ability of C1q to associate with immune complexes in autoimmune-related disorders.