Etiology of acute bronchitis in adults

A total of 126 adult patients with acute bronchitis were subjected to microbiological, virological and immunological examination. Influenza and other acute respiratory viral infections were detected in 104 (82.5%) cases of acute bronchitis. The results of microbiological examination and the study of local and systemic immunity showed that in 94.4 +/- 2.6% of the patients the development of acute bronchitis was linked with the appearance of acute pneumococcal infection irrespective of the presence, or absence, of virologically and serologically confirmed acute viral or mycoplasmal infections.     

Dynamics of functional reciprocal connections between cerebral motor cortex neurons under stimulation in cats

Activity was recorded from neurons belonging to the representation of the forelimb in the motor cortex (sulcus cruciatus, L 7–9 mm) using multiple multi-channel/barrel electrodes during acute experiments on cats. Cross-correlation analysis of impulse trains was adopted to investigate dynamics of interneuronal connections during passive flexion and electrical stimulation of the limb contralateral to the recording site. It was found that neither passive bending nor electrical stimulation of the limb leads to a significant increase in the total number of direct relationships between cortical neurons. At the same time, passive flexion does produce a considerable decrease in the number of instances of both inputs operating in neighboring neurons (50–100 µm apart) and an increase in cells located further (between 100 and 400 µm) apart. Some increase in the number of direct inhibitory interactions between neighboring neurons was observed during electrical stimulation.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Nentskii Institute of Experimental Biology, Warsaw, Poland. Center of Experimental and Clinical Medicine, Warsaw, Poland. Translated from Neirofiziologiya, Vol. 23, No. 1, pp. 73–80, January–February, 1991.     

The action of ultrasound on the contraction strength and action potential of the papillary muscle of the rat heart

In experiments on isolated rat papillary muscles the effects of therapeutic doses of ultrasound (US) (intensity, less than 2 W/cm2) with frequency of 0.88 MHz on contraction force and action potential (AP) were studied. 12 muscles (from 14) responded to 3-min exposition of the US with a rise both in contraction force and in resting tension. Sensitivity to US and a value of inotropic effect changed significantly between the preparation, and the threshold intensities of US varied from 0.3 to 2 W/cm2. In 3 experiments the inotropic effect of US was more than 100%, but in others it was about 50%. Two preparations were not sensitive to the US. The positive inotropic effect of US was accompanied by membrane depolarization (up to 20 mV) and by prolongation of AP duration measured at 10% of its amplitude (APD10). The correlation between the increase in contraction force and APD10 was demonstrated. Some preparations responded to US with high depolarization (up to 50 mV) and were inexcitable. The US induced an increase in temperature less than 1 degree C, therefore all the effects of US could not be explained as a result of temperature rise.     

Substrate Selectivity of Lysophospholipid Transporter LplT Involved in Membrane Phospholipid Remodeling in Escherichia coli

Lysophospholipid transporter (LplT) was previously found to be primarily involved in 2-acyl lysophosphatidylethanolamine (lyso-PE) recycling in Gram-negative bacteria. This work identifies the potent role of LplT in maintaining membrane stability and integrity in the Escherichia coli envelope. Here we demonstrate the involvement of LplT in the recycling of three major bacterial phospholipids using a combination of an in vitro lysophospholipid binding assay using purified protein and transport assays with E. coli spheroplasts. Our results show that lyso-PE and lysophosphatidylglycerol, but not lysophosphatidylcholine, are taken up by LplT for reacylation by acyltransferase/acyl-acyl carrier protein synthetase on the inner leaflet of the membrane. We also found a novel cardiolipin hydrolysis reaction by phospholipase A₂ to form diacylated cardiolipin progressing to the completely deacylated headgroup. These two distinct cardiolipin derivatives were both translocated with comparable efficiency to generate triacylated cardiolipin by acyltransferase/acyl-acyl carrier protein synthetase, demonstrating the first evidence of cardiolipin remodeling in bacteria. These findings support that a fatty acid chain is not required for LplT transport. We found that LplT cannot transport lysophosphatidic acid, and its substrate binding was not inhibited by either orthophosphate or glycerol 3-phosphate, indicating that either a glycerol or ethanolamine headgroup is the chemical determinant for substrate recognition. Diacyl forms of PE, phosphatidylglycerol, or the tetra-acylated form of cardiolipin could not serve as a competitive inhibitor in vitro. Based on an evolutionary structural model, we propose a “sideways sliding” mechanism to explain how a conserved membrane-embedded α-helical interface excludes diacylphospholipids from the LplT binding site to facilitate efficient flipping of lysophospholipid across the cell membrane.     

Taxonomic Interpretation of Allopatric Mammalian Forms on the Example of Two Karyoforms of <Emphasis Type="Italic">Microtus (Terricola) subterraneus</Emphasis> (Rodentia,Arvicolinae) from Eastern Europe

New European pine vole records from the Novgorod, Kaluga, Voronezh, and Belgorod oblasts were studied by sequencing of the mtDNA cytb gene (1143 bp) and by karyotyping (routine staining and G-banding techniques). The results enabled us to summarize chromosome variability of this species throughout Eastern Europe. In the sample studied, two geographically replacing chromosomal forms have been identified: northern, 2n = 54 (Novgorod and Kaluga oblasts), and southern, 2n = 52 (Voronezh and, presumably, Belgorod oblasts). Our data make the boundaries of these two karyoforms in Eastern Europe more precise and testify to intraspecific level of their taxonomic differentiation.     

Floristic inventory of wild plants of Peshawar university campus

Floristic inventory of wild plants comprised of total 129 plant species belonging to 42 families and 101 genera. Location wise UAP contributed greater amount of plant species (53%), followed by PFI (29%), UoP (15%) and Islamia College (3%). Majority of the plants were annual herbs (58%), followed by perennial herbs (29%), trees (10%) and shrubs (3%), respectively. The leading families included Poaceae, contributed 18% of all the plant species. Habitat wise, 44% of them grew in grassy plains, abandoned lands and mismanaged lawns, followed by roadsides (34%), undulating grassy plains (15%) and stony grounds with uneven topography along with stream banks and drainage ditches (7%). Still some of plant species were used as ornamentals, while some shrubs were use in fencing around fields; others were utilized as green manure, for fishing, sheltering and religious purposes. Exploring and identifying the wild flora of the campus and compiling as a handbook would help to monitor new plants introductions particularly of noxious invasive weeds in the campuses in future.     

Fusicoccin-Like Ligands in Higher Plants

Fusicoccin-like ligands in higher plants were sought by combining high performance liquid chromatography with radioreceptor analysis and radioimmunoassay. Such substances were found in genetically transformed cultured roots of horseradish, alteus and lupine as well as in native horseradish, cucumber, horse chestnut, and maize plants. In root crops such as carrot and sugar beet or in potato tubers, only traces of fusicoccin-like ligands were detected. Fusicoccin A was detected in genetically transformed cultured roots of horseradish by gas chromatography/mass spectrometry. Received October 15, 1996; accepted February 14, 1997