Comparison of the Respiratory Metabolism of Plantago lanceolata L. and Plantago major L.

Bryce, J. H. and ap Rees, T. 1985. Comparison of the respiratorymetabolism of Plantago lanceolata L. and Plantago major L.—J.exp. Bot. 36 1559–1565. The aim of this work was to discover if the respiratory metabolismof the roots of Plantago lanceolata L. differed from that ofthe roots of Plantago major L. Measurements of oxygen uptakeand dry weight of excised root systems during growth of seedlingsprovided evidence that the two species differed in the amountof respiration needed to support a given increase in dry weight.Excised root systems were given a 6-h pulse in [U-¹⁴C]sucrosefollowed by a 16.5-h chase in sucrose. The detailed distributionof ¹⁴C amongst the major components of the roots at the endof the pulse and the chase revealed no significant differencebetween the two species. Patterns of ¹⁴CO₂ production from [1-¹⁴C],[2-¹⁴C], [3,4-¹⁴C], and [6-¹⁴C]glucose of excised root systemsfrom plants of three ages were similar for the two species.It is suggested that there is no conclusive evidence for anysignificant inherent difference in the respiratory metabolismof the roots of the two species. Key words: ¹⁴C sugar metabolism, respiration, roots, Plantago     

Structural changes in the brain according to computed tomographic data in patients undergoing combination therapy for hemispheric gliomas]

Basing on CT data, the authors analyze the qualitative changes in the brain of patients with a history of multiple-modality treatment for immature neuroectodermal tumors. Plani- and volumetric parameters of the total brain, the involved and the contralateral hemispheres are compared with the same parameters in the reference group. The pattern and degree of structural changes were found related to the site of the tumor and surgery. The brain matter in both hemispheres was lost mostly in the interstitial and end portions predominantly on the side of the tumor and surgery. Changes of the brain were individual in the patients.     

Rapid recycling of triose phosphates in oak stem tissue

We report the carbon-13 and oxygen-18 isotope ratios in cellulose from the early and late wood of pedunculate oak (Quercus robur L.). The δ¹³ C value of the early wood correlates best with that of the late wood of the previous year. The δ¹⁸O value of the early wood correlates best with that of the late wood of the same year. We suggest that a biochemical explanation of these data is that there is a rapid cycle between hexose monophosphates and triose phosphates in oak stem tissue during cellulose synthesis. Evidence in support of this explanation is provided by the intramolecular distribution of ¹⁴C in labelled fructose extracted from cores of wood that had been supplied with [1?¹⁴C]- and [6-¹⁴C]glucose.     

Microglial cells of the rat brain in postnatal period (comparative immunocytochemical analysis)

In the course of the brain’s development, distribution of microglial cells was studied in rats using immunocytochemical detection. To identify the microglial cells, antibodies to lipocortin 1 (LC1) and phosphotyrosine (PT) were used. On postnatal day 1, LC1-positive microglial cells of an ameboid shape were distributed mainly in the subventricular zone; their mean density was 31±8 cells/mm² (counted across the total area of frontal sections). On postnatal day 7, microglial cells of an intermediate type were located throughout the whole brain; their density was 54±15 cells/mm². On the 15th day, LC1-positive cells were of a ramified shape, and their density reached 104±20 cells/mm² (the microglial cell density in the mature normal brain was 103±3 cells/mm²). On postnatal day 7, PT-positive cells were similar in their morphology to LC1-positive cells of an intermediate type, while their mean density was 32 cells/mm². In the mature brain, the density of PT-positive microglia was 53±5 cells/mm²; the shape of the cells in the white and gray matter of the brain was, on the whole, similar to that of LC1-positive microglia. Therefore, LC1 is a specific marker for different types of microglial cells in the developing brain. Our data about 3D distribution and morphological peculiarities of microglial cells at different stages of postnatal development are consistent with the hypothesis on the neuroectodermal origin of microglia.     

Dysfunction of kidney endothelium after ischemia/reperfusion and its prevention by mitochondria-targeted antioxidant

One of the most important pathological consequences of renal ischemia/reperfusion (I/R) is kidney malfunctioning. I/R leads to oxidative stress, which affects not only nephron cells but also cells of the vascular wall, especially endothelium, resulting in its damage. Assessment of endothelial damage, its role in pathological changes in organ functioning, and approaches to normalization of endothelial and renal functions are vital problems that need to be resolved. The goal of this study was to examine functional and morphological impairments occurring in the endothelium of renal vessels after I/R and to explore the possibility of alleviation of the severity of these changes using mitochondria-targeted antioxidant 10-(6′-plastoquinonyl)decylrhodamine 19 (SkQR1). Here we demonstrate that 40-min ischemia with 10-min reperfusion results in a profound change in the structure of endothelial cells mitochondria, accompanied by vasoconstriction of renal blood vessels, reduced renal blood flow, and increased number of endothelial cells circulating in the blood. Permeability of the kidney vascular wall increased 48 h after I/R. Injection of SkQR1 improves recovery of renal blood flow and reduces vascular resistance of the kidney in the first minutes of reperfusion; it also reduces the severity of renal insufficiency and normalizes permeability of renal endothelium 48 h after I/R. In in vitro experiments, SkQR1 provided protection of endothelial cells from death provoked by oxygen–glucose deprivation. On the other hand, an inhibitor of NO-synthases, L-nitroarginine, abolished the positive effects of SkQR1 on hemodynamics and protection from renal failure. Thus, dysfunction and death of endothelial cells play an important role in the development of reperfusion injury of renal tissues. Our results indicate that the major pathogenic factors in the endothelial damage are oxidative stress and mitochondrial damage within endothelial cells, while mitochondria-targeted antioxidants could be an effective tool for the protection of tissue from negative effects of ischemia.     

Recombinant MHC tetramers for isolation of virus-specific CD8<Superscript>+</Superscript> cells from healthy donors: Potential approach for cell therapy of posttransplant cytomegalovirus infection

Patients undergoing allogeneic hematopoietic stem cell transplantation have a high risk of cytomegalovirus reactivation, which in the absence of T-cell immunity can result in the development of an acute inflammatory reaction and damage of internal organs. Transfusion of the virus-specific donor T-lymphocytes represents an alternative to a highly toxic and often ineffective antiviral therapy. Potentially promising cell therapy approach comprises transfusion of cytotoxic T-lymphocytes, specific to the viral antigens, immediately after their isolation from the donor’s blood circulation without any in vitro expansion. Specific T-cells could be separated from potentially alloreactive lymphocytes using recombinant major histocompatibility complex (MHC) multimers, carrying synthetic viral peptides. Rapid transfusion of virus-specific T-cells to patients has several crucial advantages in comparison with methods based on the in vitro expansion of the cells. About 30% of hematopoietic stem cell donors and 46% of transplant recipients at the National Research Center for Hematology were carriers of the HLA-A*02 allele. Moreover, 94% of Russian donors have an immune response against the cytomegalovirus (CMV). Using recombinant HLA-A*02 multimers carrying an immunodominant cytomegalovirus peptide (NLV), we have shown that the majority of healthy donors have pronounced T-cell immunity against this antigen, whereas shortly after the transplantation the patients do not have specific T-lymphocytes. The donor cells have the immune phenotype of memory cells and can be activated and proliferate after stimulation with the specific antigen. Donor lymphocytes can be substantially enriched to significant purity by magnetic separation with recombinant MHC multimers and are not activated upon cocultivation with the antigen-presenting cells from HLA-incompatible donors without addition of the specific antigen. This study demonstrated that strong immune response to CMV of healthy donors and prevalence of HLA-A*02 allele in the Russian population make it possible to isolate a significant number of virus-specific cells using HLA-A*02–NLV multimers. After the transfusion, these cells should protect patients from CMV without development of allogeneic immune response.     

Production and characterization of polyclonal and monoclonal antibodies against Aflatoxin B1 oxime-BSA in an enzyme-linked immunosorbent assay

From a single aflatoxin B₁ oxime — bovine serum albumin conjugate, polyclonal and monoclonal antibody preparations were produced. The four rabbit polyclonal antisera were specific for aflatoxin Bi in a microtitration plate enzyme — linked immunosorbent assay. The monoclonal antibodies showed a wide range of differing specificities, recognizing, for example, aflatoxins B₁, B₂, G₁ and G₂; B₁ and B₂; B₁ and G₁; and G₁ alone. No antibody preparations reacted with aflatoxin M₁. The significance of these results to the strategy of anti-aflatoxin antibody production for use in quantitative enzyme immunoassays is discussed.     

Comparative study of the effectiveness of selection in diploid and autotetraploid populations]

The mitotic activity and ploidy of cells of three strains of cellus tissue by the addition of the culture medium of 0,01; 0,1 and 1 mg/l of phytohemagglutinin was studied. These strains derived from the leaves of haploid, diploid, and tetraploid plants of Lycopersicon, esculentum. The number of dividing cells under the influence of phytohemagglutinin increased by 1;5 and 4% for haploid, diploid and tetraploid strains respectively. The shift of the peak of the mitotic activity at early stages of subculture under the effect of phytohemagglutinin was noticed. Phytohemagglutinin did not change the frequencies of cells of different ploidy in all the strains analysed. A weak mutagenic activity of phytohemagglutinin in the concentrations used was observed. Cells with single bridges were more frequently observed among the aberrant cells.