Growth promotion of wheat seedlings by Exiguobacterium acetylicum 1P (MTCC 8707) a cold tolerant bacterial strain from the Uttarakhand Himalayas

Exiguobacterium acetylicum strain 1P (MTCC 8707) is a gram-positive, rod-shaped, yellow pigmented bacterium isolated from soil on nutrient agar plates at 4°C. The identity of the bacterium was arrived on the basis of the biochemical characterization, BIOLOG sugar utilization pattern and sequencing of the 16S rRNA gene. It grew at temperatures ranging from 4 to 42°C, with temperature optima at 30°C. It expressed multiple plant growth promotion attributes such as phosphate solubilization, indole acetic acid (IAA), siderophore and hydrogen cyanide (HCN) production, differentially at suboptimal growth temperatures (15 and 4°C). At 15°C it solubilized phosphate (21.1 μg of P ml(-1) day(-1)), and produced IAA (14.9 μg ml(-1) day(-1)) in tryptophan amended media. Qualitative detection of siderophore production and HCN were possible at 15°C. At 4°C it retained all the plant growth promotion attributes. Seed bacterization with the isolate, positively influenced the growth and nutrient uptake parameters of wheat seedlings in glass house studies at suboptimal cold growing temperatures.

Orientation of the bacteriochlorophyll triplet and the primary ubiquinone acceptor of Rhodospirillum rubrum in membrane multilayers determined by ESR spectroscopy (I)

Chromatophores from Rhodospirillum rubrum were oriented as multilayers on quartz slides under reducing conditions. Irradiation of these multilayers in the resonance cavity of an ESR spectrometer at 6 K yielded the spectrum of the bacteriochlorophyll dimer triplet. The relative intesities of the main six lines of the triplet were dependent on the angle subtended by the direction of the external magnetic field with plane of the multilayers. The angular dependence of the intensities of these transitions can best be interpreted in terms of one of the principal axes of the triplet lying along the plane of the membrane while the other two axes are titled 10--20 degrees away from the parallel to and normal to the membrane directions. If we assume the porphyrin planes of the dimer to be parallel and the largest splitting of the triplet transitions to correspond to those transitions in a direction normal to this plane, then these data imply that the dimer planes are nearly perpendicular to the membrane plane. Purified iron-depleted phototrap complexes were similarly oriented in reconstituted phosphatidylcholine multilayers and the angular dependence of the light-induced spectrum recorded at room temperature. A computer analysis of this angular dependence suggests that the plane of the primary ubiquinone acceptor molecule is parallel to the plane of the membrane and therefore perpendicular to the donor.

Thiourea-induced alteration in the expression patterns of some steroidogenic enzymes in the air-breathing catfish Clarias gariepinus

Previous study from our laboratory on thiourea-induced thyroid hormone depletion in mature male catfish demonstrated that thyroid hormones play a significant role in testicular function. In the present study, we aimed to analyze the changes in the expression pattern of several steroidogenic enzyme genes after thyroid hormone depletion using semi quantitative RT-PCR in both adult male and female catfish. There was a marked decrease in the 11beta-hydroxylase expression in the testis and liver while no change was observed in case of kidney. A significant decrease in 11beta-hydroxysteroid dehydrogenase transcript level in testis, liver and kidney were observed in the thiourea treated males. The results obtained corroborated with our earlier findings of testicular regression after thyroid hormone depletion. In females, expression of aromatase transcript increased in experimental group compared to control. There was no considerable change observed in the transcript level of 3beta-hydroxysteroid dehydrogenase, P450 17alpha-hydroxylase/C17-20-lyase, and 20beta-hydroxysteroid dehydrogenase in both males and females. Thus, thyroid hormones might exert modulating effect on steroidogenic enzyme genes at the transcription level.

Thyroxine-induced alterations in the testis and seminal vesicles of air-breathing catfish, Clarias gariepinus

Effect of experimentally induced thyroxine overdose on the testis and seminal vesicles was studied in the air-breathing catfish, Clarias gariepinus during the preparatory and the pre-spawning phase. The present study revealed a marked reduction in testosterone level in serum, testis and seminal vesicles (SV). Histological examination showed a considerable reduction in the number of spermatozoa/spermatids in the seminiferous tubular lumen as well as depletion of fluid in the loculi of SV. SDS-PAGE analysis of SV fluid proteins demonstrated a significant decrease in the level of a ~27 kDa protein in thyroxine treated fishes. Evidences are presented here to indicate that thyroid hormone plays a role in regulating testis and SV function in catfish.

Carboxylic and dicarboxylic acids extracted from crushed magnesium oxide single crystals

Carboxylic and dicarboxylic acids (glycolic, oxalic, malonic and succinic) have been extracted with tetrahydrofuran (THF) and H2O from large synthetic MgO crystals, crushed to a medium fine powder. The extracts were characterized by infrared spectroscopy and 1H-NMR. The THF extracts were derivatized with tert-butyldimethylsilyl (t-BDMS) for GC-MS analysis. A single crystal separated from the extract was used for an x-ray structure analysis, giving the monoclinic unit cell, space group P21/c with ao = 5.543 A, bo = 8.845 A, co = 5.086 A, and beta = 91.9 degrees, consistent with beta-succinic acid, HOOC(CH2)COOH. The amount of extracted acids is estimated to be of the order of 0.1 to 0.5 mg g-1 MgO. The MgO crystals from which these organic acids were extracted grew from the 2860 degrees C hot melt, saturated with CO/CO2 and H2O, thereby incorporating small amounts of the gaseous components to form a solid solution (ss) with MgO. Upon cooling, the ss becomes supersaturated, causing solute carbon and other solute species to segregate not only to the surface but also internally, to dislocations and subgrain boundaries. The organic acids extracted from the MgO crystals after crushing appear to derive from these segregated solutes that formed C-C, C-H and C-O bonds along dislocations and other defects in the MgO structure, leading to entities that can generically be described as (HxCyOz)n-. The processes underlying the formation of these precursors are fundamental in nature and expected to be operational in any minerals, preferentially those with dense structures, that crystallized in H2O-CO2-laden environments. This opens the possibility that common magmatic and metamorphic rocks when weathering at the surface of a tectonically active planet like Earth may be an important source of abiogenically formed complex organic compounds.

Effect of chronic ethanol administration on cholesterol and bile acid synthesis in vivo

Chronic administration of ethanol failed to a stimulate the hepatic rate of cholesterol synthesis in meal-fed rats. In contrast, chronic ethanol feeding caused a 50% inhibition in the rate of incorporation of [4-14C] cholesterol to bile acids in the bile-duct cannulated rats. It is, therefore, suggested that the decreased rate of cholesterol degradation to bile acids may play an important role in ethanol-induced accumulation of cholesterol in liver.

Further evidence for oxidative damage to hemoglobin and red cell membrane in leukemia

The presence of significant methemoglobinemia in a large number (79%) of cases of leukemia prompted us to look into the evidence for oxidative injury to the other red cell constituents, e.g. the cell membrane. Forty-five per cent of cases showed increased malonyldialdehyde (MDA) levels indicating in vivo peroxidation of membrane lipids in leukemia patients. Red cell superoxide dismutase (SOD) activity was reduced in 25% of cases while plasma alpha-tocopherol levels were markedly low in 68% of patients. The presence of an inverse correlation between MDA levels and SOD and tocopherol levels in a large number of cases suggested that the red cells in leukemia lack the ability to counter increased oxidative stress. Low hemoglobin content of the red cells in these patients seemed to contribute to the oxidative injury to the membrane by rendering the latter more accessible to the oxidants. While methemoglobinemia may enhance tissue hypoxia, membrane lipid peroxidation could explain the shortened erythrocyte life-span and anemia in leukemia.

Phenotypic heterogeneity of erythroblasts in erythroblastic leukemia revealed by monoclonal antibodies

Eight cases each of erythroleukemia (AML-M6) and erythroblastic crisis of chronic granulocytic leukemia (CGLBC-E) were immunophenotyped with the help of a panel of lineage-associated monoclonal antibodies (McAbs). The latter included those reactive with erythroid progenitor (BFU-E and CFU-E) and erythroid precursors at different stages of maturation. In six of eight cases of AML-M6, erythroblasts revealed an immature phenotype, as evident from reactivity of the blast cells with McAbs directed against the earlier stages of erythroid maturation. One case had the phenotype of CFU-E, and in the remaining case of AML-M6 the erythroblasts showed a "mature" surface antigenic profile. This immunophenotypic spectrum was unrelated to the morphologic maturity of the erythroblasts. In two cases of CGLBC-E, an early erythroblastic phenotype was observed, while in as many cases a "mature" phenotype was present. Four of eight cases, however, revealed a mixed, erythroid plus myeloid phenotype. In one of the four cases, two separate blast populations, which represented erythroblasts and myeloblasts, could be identified. In the remaining three cases the blasts were morphologically homogeneous and undifferentiated. High incidence of HLA-DR positivity in the latter three cases suggests the primitive nature of blasts cells and their closeness to the putative "bipotent" myeloid stem cell. Our study has shown phenotypic heterogeneity of blast cells in AML-M6 and CGLBC-E.

Access to nursing information resources

There is a wealth of nursing information available in multiple formats (journal articles, books, audiovisuals, computer software, pamphlets, dissertations, etc.). But the resources are not readily available to help the nurse identify needed materials quickly and easily. Current access to nursing journal articles and books is evaluated in detail; the need to collect and organize other types of nursing information is outlined. Better control of nursing information is a must if nurses are to take their place alongside other health care professionals.

Spontaneously developing autoantibody to factor VIII in an elderly woman: diagnostic and therapeutic challenges

An elderly woman with a continuously bleeding small wound was investigated for the presence of antibodies to FVIII using activated partial time-based screening and confirmatory tests. A late acting coagulation factor inhibitor was detected. The same was characterised to be a low titre antibody against FVIII (5.2 Bethesda units). Cryoprecipitate infusions, corticosteroids and topical desmopressin were unsuccessful in controlling the bleeding. Addition of cyclophosphamide brought about stoppage of bleeding and disappearance of the autoantibody.

A review on potential approach for in silico toxicity analysis of respirable fraction of ambient particulate matter

Epidemiological and toxicological studies have shown the adverse effect of ambient particulate matter (PM) on respiratory and cardiovascular systems inside the human body. Various cellular and acellular assays in literature use indicators like ROS generation, cell inflammation, mutagenicity, etc., to assess PM toxicity and associated health effects. The presence of toxic compounds in respirable PM needs detailed studies for proper understanding of absorption, distribution, metabolism, and excretion mechanisms inside the body as it is difficult to accurately imitate or simulate these mechanisms in lab or animal models. The leaching kinetics of the lung fluid, PM composition, retention time, body temperature, etc., are hard to mimic in an artificial experimental setup. Moreover, the PM size fraction also plays an important role. For example, the ultrafine particles may directly enter systemic circulations while coarser PM10 may be trapped and deposited in the tracheo-bronchial region. Hence, interpretation of these results in toxicity models should be done judiciously. Computational models predicting PM toxicity are rare in the literature. The variable composition of PM and lack of proper understanding for their synergistic role inside the body are prime reasons behind it. This review explores different possibilities of in silico modeling and suggests possible approaches for the risk assessment of PM particles. The toxicity testing approach for engineered nanomaterials, drugs, food industries, etc., have also been investigated for application in computing PM toxicity.

Characterization of a novel form of transferrin receptor preferentially expressed on normal erythroid progenitors and precursors

A panel of monoclonal antibodies (MoAbs) against cell surface proteins of early BFUe progeny was characterized. Five of these antibodies (Abs) reacted with normal erythroid, but not myeloid, bone marrow cells. Each of the five antibodies, typified by Ab 69.20, immunoprecipitated a dimeric complex of 185,000, which is composed of two identical disulfide-bonded subunits. This antigen had affinity for transferrin, and was essentially identical in biochemical characteristics to transferrin receptors precipitated with the well-characterized MoAbs OKT9 and 5E9. However, this form of transferrin receptor lacked both the OKT9 and 5E9 antigenic determinants and, moreover, the 69.20 epitope was absent from the conventional transferrin receptor, as defined by Abs OKT9 and 5E9. Modulation experiments demonstrated that both 69.20 and OKT9 modulated large, virtually independent populations of transferrin receptors. Both forms of transferrin receptor appeared to be derived from the product of a single gene, but the form defined by MoAb 69.20 apparently predominates in cells of the erythroid lineage and some transformed cell types that manifest a special requirement for iron. These data suggest that cells with a high iron requirement synthesize two forms of transferrin receptor, possibly by means of differential mRNA splicing or by posttranslational modification of the transferrin receptor.

Acute superior mesenteric vein thrombosis associated with factor V 'Leiden' gene mutation

OBJECTIVES

To study thrombophilia states in Indian patients with acute spontaneous superior mesenteric vein thrombosis (SMVT).

METHODS

Two men with this condition, a 56 year old and a 31 year old presenting with acute SMVT, demonstrated on CT scan, were subjected to a thrombophilia screen consisting of Protein C, S, antithrombin levels, lupus anticoagulant, anticardiolipin antibodies, fibrinogen levels, factor VIII levels, factor V 'Leiden' gene mutation, and paroxysmal nocturnal hematuria screen.

RESULTS

A thrombophilia screen showed factor V 'Leiden' gene mutation (heterozygous) in both cases. Additionally, the first patient had high fibrinogen levels and the second high factor VIII levels. Both patients are currently on long-term anticoagulation.

CONCLUSION

Factor V 'Leiden' gene mutation in association with other thrombophilic factors may predispose to spontaneous superior mesenteric vein thrombosis.

20-Hydroxyecdysone mediated activation of larval haemolymph protein uptake by fat body cells of Corcyra cephalonica (Insecta)

Evidence is presented here to show that 20-hydroxyecdysone is essential for the activation of the larval fat body for differential uptake of larval haemolymph proteins (LHPs). By using radiolabelled LHPs it is shown that the fat body cells of Corcyra cephalonica selectively incorporate LHPs during late-larval and prepupal development. Fluorographic analysis of the labelled fat body proteins from prepupal stage separated on sodium dodecyl-sulphate polyacrylamide gels suggests that the LHPs are sequestered without any degradation. Although, during the last larval instar the uptake of all the three LHPs (LHP 1, LHP 2 and LHP 3) by the fat body cells is very low, 20-hydroxyecdysone treatment of early, mid or late-last instars causes a significant increase in uptake of all the three LHPs. However, the response to hormone treatment was more pronounced in late-last instar when compared to early and mid-last instar.

CINAHL list of subject headings: a nursing thesaurus revised

The rationale and methods for revising the thesaurus of one of the major health sciences indexing tools are discussed. Computer production of the Cumulative Index to Nursing & Allied Health Literature and the possibility of online access mandated a revision of the list of subject headings. CINAHL has maintained a policy of responding to user needs and to changes in the nursing and allied health literature, and user input was encouraged during revision of the thesaurus. The methods of structural revision are described, and major changes in the thesaurus are detailed. Modification of the thesaurus is expected to have a far-reaching impact on the retrieval of information in nursing and allied health. Nursing and Allied Health (CINAHL) is now available online through DIALOG (file 218) and BRS (access code NAHL).

SFL 23.6: a monoclonal antibody reactive with CFU-E, erythroblasts, and erythrocytes

A cytotoxic (IgG2b) monoclonal antibody (McAb) for a novel erythroid differentiation antigen was generated by hyperimmunizing young mice with mononuclear cells obtained from livers of 20- to 22-week-old fetuses. This McAb, designated SFL 23.6, shows an extremely well-defined reactivity with the cells of the erythroid lineage at all stages of maturation as evident from the labeling of morphologically identifiable erythroid precursors and of erythrocytes present in peripheral blood, bone marrow, and fetal liver, and from its reactivity with culture-derived erythroblasts. The nonerythroid cells present in these and other tissue preparations were not labeled by SFL 23.6. The erythroid lineage specificity of McAb SFL 23.6 was confirmed by a cell-sorting experiment in which 97% of the cells in the fluorescent fraction sorted from SFL 23.6-treated bone marrow cells were erythroid precursors at various stages of maturation. Complement-mediated cytotoxicity and progenitor cell-sorting experiments showed that most (greater than 90%) of the late erythroid progenitors (CFU-E) and only a small proportion of the early erythroid progenitors (BFU-E) express the antigenic determinant identified by SFL 23.6. The myeloid progenitors (CFU-GM) and multilineage progenitors (CFU-GEMM) were negative for the SFL 23.6 antigenic determinant. The antigen recognized by SFL 23.6 has not been determined as yet. Because of the pattern of its reactivity and its dependence on sialic acid residues, the possibility of its relationship to glycophoria A was entertained. However, previous work using antiglycophorin McAbs (R-10) has shown that this determinant is not expressed in CFU-E. Therefore, among the erythroid lineage-specific McAbs described thus far, SFL 23.6 is unique in its reactivity with CFU-E and the mature erythron. Reagents with such specificity may be useful in studies of erythroid differentiation and commitment.