Biomedical subjects

E V Romanova

Publications and source records attributed to E V Romanova.

At least 19 recordsLinked to original sources

PubMed2006

[Detection of Borrelia DNA in the Borrelia burgdorferi sensu lato complex in the blood of patients with Ixodes tick-borne borrelios].

Borrelia DNA was detected by polymerase chain reaction in the blood of patients who had suffered from tick suction. DNA was revealed in 28.7 of the blood samples from patients with the erythematous form of Ixodes tick-born borrelioses (ITBB) and in 14.3% of those diagnosed as having tick-borne encephalitis. Blood Borrelia DNA was not detected in patients with end-stage and chronic ITBB. Comparing the results of detection of DNA with those Borrelia protein antibodies has shown that the antibody titers detectable in the patients having Borrelia DNA are lower than those in the patients with the same form of ITBB and without DNA. The detection of DNA should be accomplished in the first 4 weeks after tick bite.

Animals↗

PubMed2001

Direct assay of Aplysia tissues and cells with laser desorption/ionization mass spectrometry on porous silicon.

Desorption/ionization on porous silicon (DIOS) is a form of laser desorption mass spectrometry that allows for the direct mass analysis of a variety of analytes without the addition of organic matrix. Protocols are described for the direct analysis of exocrine tissue and single neurons using DIOS-MS. The atrial gland of Aplysia californica was blotted on to porous silicon and analyzed with DIOS-MS in the range m/z 1000-4000. The ability to culture invertebrate neurons directly on porous silicon is also presented. Isolated bag cells regenerated neuronal processes in culture on porous silicon. DIOS-MS allowed the direct detection of the peptides contained in individual cultured neurons indicating that with appropriate protocols, DIOS can be used with biological samples with considerable thickness.

Animals↗

PubMed2001

Cerebrin prohormone processing, distribution and action in Aplysia californica.

The isolation, characterization, and bioactivity in the feeding circuitry of a novel neuropeptide in the Aplysia californica central nervous system are reported. The 17-residue amidated peptide, NGGTADALYNLPDLEKIamide, has been termed cerebrin due to its primary location in the cerebral ganglion. Liquid chromatographic purification guided by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry allowed the isolation of the peptide with purity adequate for Edman sequencing. The cerebrin cDNA has been characterized and encodes an 86 amino acid prohormone that predicts cerebrin and one additional peptide. Mapping using in situ hybridization and immunocytochemistry showed that cerebrin containing neuronal somata are localized almost exclusively in the cerebral ganglion, mostly in the F- and C-clusters. Both immunostaining and mass spectrometry demonstrated the presence of cerebrin in the neurohemal region of the upper labial nerve. In addition, immunoreactive processes were detected in the neuropil of all of the ganglia, including the buccal ganglia, and in some interganglionic connectives, including the cerebral-buccal connective. This suggests that cerebrin may also function as a local signaling molecule. Cerebrin has a profound effect on the feeding motor pattern elicited by the command-like neuron CBI-2, dramatically shortening the duration of the radula protraction in a concentration-dependent manner, mimicking the motor-pattern alterations observed in food induced arousal states. These findings suggest that cerebrin may contribute to food-induced arousal in the animal. Cerebrin-like immunoreactivity is also present in Lymnaea stagnalis suggesting that cerebrin-like peptides may be widespread throughout gastropoda.

Amino Acid Sequence↗

PubMed2000

Peptide profiling of cells with multiple gene products: combining immunochemistry and MALDI mass spectrometry with on-plate microextraction.

Due to the intracellular chemical complexity and a wide range of transmitter concentrations, the detection of the complete set of peptide transmitters in a single cell is problematic. In the current study, a multidisciplinary approach combining single-cell MALDI-MS peptide profiling, northern analysis, in situ hybridization, and immunocytochemistry allows characterization of a more complete set of neurotransmitters than individual approaches in the Aplysia californica B1 and B2 motor neurons. Because different results were obtained using both in situ and immunohistochemical techniques compared to previous reports, MALDI-MS assays have been used to examine CP1-related gene products in these cells. However, MALDI with standard sample preparation does not detect the presence of the CP1 gene products. A novel on-plate microextraction approach using concentrated MALDI matrix 2,5-dihydroxybenzoic acid with a mixture of acetone and water as the solvent has been developed to allow the detection of trace-level gene expression products. Both neuropeptide precursors in the B1 and B2 neurons-the SCP and CP1 prohormones-end with large peptides that have multiple cysteine residues. For SCP, MALDI-MS verifies the presence of a novel 9325 Da SCP-related peptide. In the case of CP1, a disulfide-bonded homodimer is detected and the disulfide bonding pattern elucidated using MALDI-MS coupled with on-plate enzymatic digestion.

Amino Acid Sequence↗

PubMed1999

In situ sequencing of peptides from biological tissues and single cells using MALDI-PSD/CID analysis.

The ability to directly sequence peptides from biological cells using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with postsource decay (PSD) and collision-induced dissociation (CID) fragment ion mass analysis is explored. Three different sample preparation methods are described for sequencing peptides in tissue samples and in single neurons from the invertebrate model Aplysia californica. To characterize peptides from the atrial gland, MALDI-PSD/CID is applied directly to a tissue blot covered with the matrix alpha-cyano-4-hydroxycinnamic acid (CHCA). The resulting fragment ions combined with database searching confirm the structure of several novel peptides encoded by egg-laying hormone genes. Moreover, MS profiling of a single unidentified neuron detects peptides with molecular weights of myomodulins C and E; this assignment is confirmed using MALDI-PSD with the matrix 2,5-dihydroxybenzoic acid (DHB). DHB does not always provide adequate fragmentation for PSD experiments; therefore, a unique dual-matrix sampling method, employing both DHB and CHCA, is developed to directly sequence a decapeptide from a single cerebral ganglion B cell. Mass accuracy of fragment ions from cellular samples is typical for the instrument employed and is not deleteriously affected by the morphology and complexity of the samples.

Amino Acid Sequence↗

PubMed1996

Behavioral changes induced by GABA-receptor agonists in Lymnaea stagnalis L.

1. GABA, the GABAA receptor agonist, muscimol, and the GABAB receptor agonist, baclofen, were tested to study the involvement of the GABA neurotransmitter system in control of behaviour in the freshwater pulmonate snail, Lymnaea stagnalis L. Single injections of GABA (1-10 micrograms/ gbw) into the haemocoel of intact snails elicits a sequence of behavioural changes subsequently affecting feeding, locomotion, escape reactions, male mating behaviour and respiration. 2. Both muscimol and baclofen mimic distinct aspects of GABA action implying that the GABA action is mediated by both types of receptors. 3. The modulatory actions of GABA, muscimol, and baclofen on feeding were manifested as opening of the mouth and triggering of specific radular movements (e.g., protraction, retraction, rasping). 4. Baclofen (1-10 micrograms/gbw) evoked the full erection of the penis for a time long enough for natural copulation, while GABA itself caused only partial eversion of the preputium. Muscimol was less effective than GABA. The latency to penis eversion varied in a dose-dependent manner. The data emphasize the participation of baclofen-sensitive receptors in control of reproduction. 5. GABA and baclofen induced withdrawal of the head and anterior part of the foot accompanied by arrest of locomotion and respiration could be considered to be an escape reaction. 6. Muscimol (1-5 micrograms/gbw) failed to elicit withdrawal reactions but caused the loss of normal orientation and longitudinal contractions of the foot. 7. All the agents tested inhibited locomotion in a dose-dependent manner, for a substantial period of time. A decrease in total locomotor activity lead to the failure of animals to attach to the underlying surface, to have foot contractions and also to diminish locomotor velocity. 8. The majority of animals maintained the stereotyped complex reactions of respiration, but with restricted clockwise turning of the shell after drug treatment. 9. All the substances were shown to shift the background behavioural state characterised by high BSSs to a state similar to "rest" which was awarded a low BSS. It is concluded that the GABA neurotransmitter system can play an important role in activation and coordination of neuronal ensembles underlying behaviour and behaviour selection in Lymnaea stagnalis L.

Animals↗

PubMed1987