Evaluating of influence of repeated thaw/freeze cycles on IgG and IgM stability

The purpose of this study was evaluating influence of repeated cycles of thawing and freezing serum samples on IgG and IgM stability. Serum positive samples for anti-cytomegalovirus and antimeasles virus IgG and/or IgM were aliquoted. Tubes containing 100 microl aliquot were frozen at -20 degrees C. Samples were repetitively thawed and froze in one to ten cycles. Antibodies presence was examined with commercially available ELISA tests. All samples reminded positive even after ten repeated thaw/freeze cycles.     

Glutamate induces series of action potentials and a decrease in circumnutation rate in Helianthus annuus

Reports concerning the function of glutamate (Glu) in the electrical and movement phenomena in plants are scarce. Using the method of extracellular measurement, we recorded electrical potential changes in the stem of 3‐week‐old Helianthus annuus L. plants after injection of Glu solution. Simultaneously, circumnutation movements of the stem were measured with the use of time‐lapse images. Injection of Glu solution at millimolar (200, 50, 5 mM) concentrations in the basal part of the stem evoked a series of action potentials (APs). The APs appeared in the site of injection and in different parts of the stem and were propagated acropetally and/or basipetally along the stem. Glu injection also resulted in a transient, approximately 5‐h‐long decrease in the stem circumnutation rate. The APs initiated and propagating in the sunflower stem after Glu injection testify the existence of a Glu perception system in vascular plants and suggest its involvement in electrical, long‐distance signaling. Our experiments also demonstrated that Glu is a factor affecting circumnutation movements.     

Identification and structural characterization of FYVE domain-containing proteins of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Background  

FYVE domains have emerged as membrane-targeting domains highly specific for phosphatidylinositol 3-phosphate (PtdIns(3)P). They are predominantly found in proteins involved in various trafficking pathways. Although FYVE domains may function as individual modules, dimers or in partnership with other proteins, structurally, all FYVE domains share a fold comprising two small characteristic double-stranded β-sheets, and a C-terminal α-helix, which houses eight conserved Zn²⁺ ion-binding cysteines. To date, the structural, biochemical, and biophysical mechanisms for subcellular targeting of FYVE domains for proteins from various model organisms have been worked out but plant FYVE domains remain noticeably under-investigated.     

Helicobacter pylori VacA Toxin/Subunit p34: Targeting of an Anion Channel to the Inner Mitochondrial Membrane

The vacuolating toxin VacA, released by Helicobacter pylori, is an important virulence factor in the pathogenesis of gastritis and gastroduodenal ulcers. VacA contains two subunits: The p58 subunit mediates entry into target cells, and the p34 subunit mediates targeting to mitochondria and is essential for toxicity. In this study we found that targeting to mitochondria is dependent on a unique signal sequence of 32 uncharged amino acid residues at the p34 N-terminus. Mitochondrial import of p34 is mediated by the import receptor Tom20 and the import channel of the outer membrane TOM complex, leading to insertion of p34 into the mitochondrial inner membrane. p34 assembles in homo-hexamers of extraordinary high stability. CD spectra of the purified protein indicate a content of >40% β-strands, similar to pore-forming β-barrel proteins. p34 forms an anion channel with a conductivity of about 12 pS in 1.5 M KCl buffer. Oligomerization and channel formation are independent both of the 32 uncharged N-terminal residues and of the p58 subunit of the toxin. The conductivity is efficiently blocked by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), a reagent known to inhibit VacA-mediated apoptosis. We conclude that p34 essentially acts as a small pore-forming toxin, targeted to the mitochondrial inner membrane by a special hydrophobic N-terminal signal.     

The ammonium content in the tissues of selected species of squid (Cephalopoda: Teuthoidea)

The ammonium ion (NH₄⁺) content in the mantles, fins, arms, haemolymph, and buoyancy fluid of 17 species of squids belonging to nine families was determined. Great individual variation of ammonium concentration was found in the buoyancy fluid of Liocranchia reinhardti(Steenstrup, 1856), i.e. 38–1108 mM, and in the vacuolized tissues of Histioteuthis macrohista N. Voss, 1969, i.e. 50–775 mM.     

Diagnosis of cerebello-pontine angle tumors

History and results of investigations in 34 patients with cerebello-pontine angle tumours are presented. Tumour was diagnosed in the first, audiological stage of the disease only in 4 patients. In 7 more patients additional symptoms of central nervous system focal disorders occurred. The remaining 23 patients were in the third stage of the disease with symptoms of increased intracranial pressure. The main reason for such a late diagnosis of the tumour was neglecting of the early audiological symptoms of the disease by patients and by general practitioners as well.     

Our experience with surgical treatment of primary cancer of the gallbladder

Witkin 1980-1988, 42 patients (4 males and 38 females) were operated for the gall-bladder cancer; it makes 2.9% of the patients who underwent cholecystectomies. Average age of female patients was 65 and males--71 years. No typical complaints were revealed making possible an early diagnosing of the gall-bladder cancer. The far advanced stages of this cancer were found in 41 cases. In i case no macroscopic features of the cancer were found. Cancer was diagnosed by means of histopathological examination. One patient (woman) survived more than 3 years after operation; 3 women survived more than 1 year. Average survival is 4 months.