Morphological effects in rats following a 22-day space flight

A morphological examination of 27 rats flown onboard the biosatellite and sacrificed on the 1st-2nd and 26-27th postflight days demonstrated no significant changes in the structural organization of the vital organs and systems of the animal body. It was, however, found that the space exposure induced morphologically detectable changes in the musculo-skeletal system, hemo- and lymphopoiesis, hypothalamic-pituitary-adrenal system and the juxtaglomerular apparatus of the kidneys. The changes were reversible and nonspecific, and could be seen in animals exposed to ground-based hypokinetic and other stress experiments. Postflight the animals developed some reactions that were similar to those in humans. This helps to identify the morphological substrate of certain changes in the human body and to investigate their pathogenesis.     

Specific inhibition of macrophage adherence in animals with post-traumatic autoallergic aspermatogenesis

The macrophage adherence inhibition was studied in the peritoneal macrophages of guinea pigs with induced posttraumatic aspermatogenesis at various periods after the testis injury. Reliable peritoneal macrophages adherence inhibition was observed in the presence of the testis-specific antigen. The adherence inhibition reflected the autoimmune character of the testis affection.     

Hyperoxia stimulates endothelin-1 secretion from endothelial cells; modulation by captopril and nifedipine

OBJECTIVE: Validation of an open-circuit multibreath nitrogen washout technique (MBNW) for measurement of functional residual capacity (FRC). The accuracy of FRC measurement with and without continuous viscosity correction of mass spectrometer delay time (TD) relative to gas flow signal and the influence of baseline FIO2 was investigated. DESIGN: Laboratory study and measurements in mechanically ventilated patients. SETTING: Experimental laboratory and anesthesiological intensive care unit of a university hospital. PATIENTS: 16 postoperative patients with normal pulmonary function (NORM), 8 patients with acute lung injury (ALI) and 6 patients with chronic obstructive pulmonary disease (COPD) were included. INTERVENTIONS: Change of FIO2 from baseline to 1.0. MEASUREMENTS AND MAIN RESULTS: FRC was determined by MBNW using continuous viscosity correction of TD(TDdyn), a constant TD based on the viscosity of a calibration gas mixture (TD0) and a constant TD referring to the mean viscosity between onset and end of MBNW (TDmean). Using TDdyn, the mean deviation between 15 measurements of three different lung model FRCs (FRCmeasured) and absolute volumes (FRCmodel) was 0.2%. For baseline FIO2 ranging from 0.21 to 0.8, the mean deviation between FRCmeasured and FRCmodel was -0.8%. However, depending on baseline FIO2, the calculation of FRC using TDmean and TD0 increased the mean deviation between FRCmeasured and FRCmodel to 2-4% and 8-12%, respectively. In patients (n = 30) the average repeatability coefficient was 6.0%. FRC determinations with TDmean and TD0 were 0.8-13.3% and 4.2-23.9% (median 2.7% and 8.7%) smaller than those calculated with TDdyn. CONCLUSION: A dynamic viscosity correction of TD improves the accuracy of FRC determinations by MBNW considerably, when gas concentrations are measured in a sidestream. If dynamic TD correction cannot be performed, the use of constant TDmean might be suitable. However, in patient measurements this can cause an FRC underestimation of up to 13%.     

Localization of substance P and leucine enkephalin in the nerve terminals of the guinea pig paracervical ganglion

Immunoreactivities (IR) of substance P and leucine enkephalin have been demonstrated in the guinea-pig paracervical ganglion by an immunogold electron microscope method. Both substance P-IR and leucine enkephalin-IR were detected in large synaptic vesicles with electron-dense cores. The former neuropeptide was detected in nerve terminals and varicosities comprised mainly of large vesicles with electron-dense cores; the latter was detected in nerve terminals and varicosities that also included small, clear synaptic vesicles. In a minority of nerve terminals and varicosities coexistence of both immunoreactivities could be demonstrated within vesicles with an electron-dense core. Also present in these nerve terminals and varicosities were small, clear synaptic vesicles, though these were unreactive.     

Spontaneous mutagenesis of a plant potyvirus genome after insertion of a foreign gene

The RNA genome of tobacco etch potyvirus (TEV) was engineered to express bacterial beta-glucuronidase (GUS) fused to the virus helper component proteinase (HC-Pro). It was shown previously that prolonged periods (approximately 1 month) of TEV-GUS propagation in plants resulted in the appearance of spontaneous deletion variants. Nine deletion mutants were identified by nucleotide sequence analysis of 40 cDNA clones obtained after polymerase chain reaction amplification. The mutants were missing between 1,741 and 2,074 nucleotides from TEV-GUS, including the sequences coding for most of GUS and the N-terminal region of HC-Pro. This region of HC-Pro contains determinants involved in helper component activity during aphid transmission, as well as a highly conserved series of cysteine residues. The deletion variants were shown to replicate and move systemically without the aid of a helper virus. Infectious viruses harboring the two largest HC-Pro deletions (termed TEV-2del and TEV-7del) were reconstructed by subcloning the corresponding mutated regions into full-length DNA copies of the TEV genome. Characterization of these and additional variants derived by site-directed mutagenesis demonstrated that deletion of sequences coding for the HC-Pro N-terminal domain had a negative effect on accumulation of viral RNA and coat protein. The TEV-2del variant possessed an aphid-nontransmissible phenotype that could be rescued partially by prefeeding of aphids on active HC-Pro from another potyvirus. These data suggest that the N-terminal domain of HC-Pro or its coding sequence enhances virus replication or genome expression but does not provide an activity essential for these processes. The function of this domain, as well as a proposed deletion mechanism involving nonhomologous recombination, is discussed.     

Composition and structure of resins in lube distillates from west siberian crudes

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 27–30, February, 1994.