The electron microscopic characteristics of stress lung

The influence of long-term (6 hours) immobilization stress on morphofunctional state of lung air-blood barrier was studied in experiments of the rats. It was shown that stress provoked the marked ultrastructural changes in the lungs, which were as follows: lung tissue oedema, pronounced thickening of lung air-blood barrier and its separate layers, edema-hemorrhagic syndrome, alveolar epithelial injury, disturbance of lung surfactant systems. Such a pathological complex may be designated as a "stress lung".     

家兔中脑导水管周围灰质中注射八肽胆囊收缩素（CCK—8）拮抗吗啡镇痛和...

We have reported that intracerebroventricular (i. c. v.) injection of 1-4 ng of CCK-8 to the rat produced a remarkable antagonistic effect on morphine analgesia. In order to study the species specificity and the site of action, CCK-8 was microinjected into the PAG of the rabbit, and its influence on morphine analgesia and electroacupuncture analgesia was observed. The latency of the escape response (ERL) to radiant heat focused on the snout was measured as an index of the pain threshold. Microinjections were made via cannulae chronically implanted into the PAG. The drug solutions were delivered in a volume of 1 microliter, at a speed of 0.125 microliter/min. The ERL was measured for a period of 60 or 70 minutes at 10 min intervals. 1. CCK-8 administered unilaterally to the PAG of the rabbit at a dose of 3 ng antagonized the analgesia induced by morphine (4 mg/kg, i. v.) by 73% (P less than 0.001), and reduced the analgesic effect of electroacupuncture by 67% (P less than 0.001). These effects were dose-dependent within the range from 1.5 ng to 6.0 ng. The effect of CCK-8 was reversed by CCK receptor blocker proglumide (4 microliters, intra-PAG injection). Unsulfated CCK-8 (CCK-us) had no effect in this regard. These results indicate that in the PAG of the rabbit, exogenously administered CCK-8 was capable of antagonizing opioid analgesia by the activation of CCK receptors. 2. Two groups of rabbits were given with morphine (2 mg/kg, i. v.) and simultaneous injection of CCK-8 antiserum (CCK-AS, 1 microliter) or normal rabbit serum (NRS) into the PAG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Importance of associated microorganisms in the development of acute pneumonia

Sputum samples obtained from 106 patients with acute pneumonia have been studied by the quantitative microbiological method. Different microbial associations have been shown to play an important role in the development of acute pneumonia (67.9%). Microbiological studies have revealed the prevalence of pneumococci in the etiological structure of the disease. Staphylococci, hemophilic bacteria and Neisseria have been found to take part in the development of acute pneumonia in a lesser number of cases and more often occur in combination with pneumococci or form different associations themselves. The so-called "etiological" type of microbial associations has been determined, two or three microbial species being isolated at high concentrations (10(6) and over) and the percentage of patients with such combinations being 59.7 +/- 5.8%. The analysis of the clinical course of the disease has revealed that the presence of different microbial species in patients linked, to a great extent, with the clinical picture of the disease. These data may be used for prescribing adequate etiotropic therapy and for prognostication. Quantitative bacteriological studies carried out in the dynamics of the disease permit timely detection of changes in the microflora of the respiratory tracts, the evaluation of the effectiveness of antibacterial therapy in the process of its implementation and the rational correction of therapeutic measures.     

The taxonomy of obligate anaerobic bacteria

Studies on the chemotaxonomy of obligate anaerobic bacteria have been made. The combination of gas chromatography and mass spectrometry with computer-assisted analysis, permitting the multicomponent analysis of all products of bacterial metabolism and bacterial cell components, has been shown to be a research method, quite suitable for such studies. The chromatographic profiles of the end products of metabolism in anaerobic cultures of different age have been found to differ not in the set and number of peaks indicating various metabolites, but only in the concentration of metabolites, increasing in the process of prolonged incubation. The authors believe that the national microbiological "library" of the chromatographic profiles of anaerobic organisms should be created and the album of typing chromatographic profiles should be published; besides, data on new profiles should regularly appear in magazines.     

NADPH:cytochrome P-450(c) reductase: Biochemical characterization in rat brain and cultured neurons and evolution of activity during development

NADPH:cytochrome P-450 (c) reductase is a microsomal enzyme which is involved in the cytochrome P-450-dependent biotransformation of many exogenous agents as well as of some endogenous molecules. Using cytochromec as a substrate, the kinetic parameters of this enzyme were determined in brain microsomes. The comparison of the NADPH:cytochrome P-450 reductase's V_max values and cytochrome P-450 contents in both fractions, suggests a role of cerebral NADPH:cytochrome P-450 reductase in cytochrome P-450 independent pathways. This is also supported by the different developmental pattern of brain enzyme as compared to the liver enzyme, and by the presence of a relatively high NADPH:cytochrome P-450 reductase activity in immature rat brain and neuronal cultures, while cytochrome P-450 was hardly detectable in these preparations. The enzyme activity was not induced by a phenobarbital chronic treatment neither in the adult brain nor in cultured neurons, suggesting a different regulation of the brain enzyme expression.     

Cloning and nucleotide sequence analysis of genes coding for the major chlorophyll-binding protein of the moss Physcomitrella patens and the halotolerant alga Dunaliella salina

Two clones have been isolated from a genomic library of the moss Physcomitrella patens and a cDNA library of the halotolerant green alga Dunaliella salina. The isolates contain genes coding for the major light-harvesting chlorophyll-a/b-binding protein (CAB) in the photosystem II (PSII) light-harvesting complex (LHCII). The 2544-bp insert of the moss genomic clone contains the complete CAB-coding region and 5' and 3' flanking sequences. The coding region contains an intron of 359 bp which is spanned by a pair of 9-bp perfect direct repeats. There are two CCAAT boxes and five enhancer-like elements related to (G)TGGTTTAAA(G) (Weiher et al., 1983) residing in the intron. Comparisons of the moss cab gene with sequences of light-inducible genes of higher plants reveal homologous and repeated sequences similar to the enhancer element in the 5' region upstream from the TATA and CCAAT boxes thought to be responsive to light inducibility. The 1256-bp algal cDNA contains the complete CAB-coding sequence, a 170-bp 5'-nontranslated region, and a 264-bp 3'-nontranslated region. While the overall homology in the nontranslated regions is low between the cab gene of the moss and that of the alga, the 3'-nontranslated regions of the two contain some sequences that are conserved among the cab genes in higher plants. The deduced amino acid sequences of these two clones are highly conserved except for the N-terminal region. Their hydropathic plots are very similar and both possess three hydrophobic segments that are likely alpha-helical transmembrane segments. The proposed CAB transit peptide sequence of the alga is divergent from that of the moss or higher plants, suggesting that they may have evolved from different origins. Southern blot analysis shows that the cab genes in the moss and the alga, as in higher plants, are encoded by a number of homologous genes constituting a multigene family.     

Paleobotanical studies inFagaceae of the European Tertiary

A systematic reassessment of megafossil records ofFagaceae in Central Europe has been undertaken on the basis of leaf cuticular characters. The oldest representatives date back to the Eocene:Quercus subhercynica spec. nova,Dryophyllum furcinerve (Rossm.)Schmalh.,Trigonobalanopsis rhamnoides (Rossm.) gen. & comb. nov. In the Oligocene other members of extant genera appear:Quercus rhenana (Weyl. & Kilpp.)Knobloch & Kvaek,Fagus attenuata Goepp.,Lithocarpus saxonicus spec. nova. In the Neogene these ancient taxa (except inFagus lineage), are gradually replaced by deciduous species ofQuercus andCastanea. Trigonobalanus andCastanopsis are recorded by fruits (or wood) only.     

中枢多巴胺神经元放电活动的特点

中脑黑质和腹侧被盖区DA神经元自发放电活动的特点表现在:动作电位时程较宽(2～5ms),伴有上升相切迹;放电频率较慢(1～10spikes/s);有单放电(single firing)和爆发性放电(burst firing)两种型式,前者动作电位幅度无显著改变,后者动作电位幅度逐个减低,时程逐个加宽,并且动作电位间隔逐渐延长。DA受体激动剂或D_2亚型选择性激动剂抑制DA神经元放电活动,它能被DA受体拮抗剂所逆转。