Heterogeneity of immune responses to various Aspergillus species in patients with allergic respiratory diseases

In the present study, allergenic significance of thirteen species of Aspergillus and their allergenic and antigenic relationship was studied. Of the 3025 ID tests performed with the 13 species of Aspergillus on 289 patients suffering with allergic respiratory diseases, 627 (20.7%) were positive (1+ to 4+), 386 (12.8%) being significantly positive (2+ to 4+) . Of the 64 patients eliciting a positive cutaneous response to at least one species, 42(65.6%) were positive to 5 or less number of species while others showed a broad spectrum of positive skin reactivity to different Aspergillus extracts. In RAST inhibition assays using pooled sera ofpatients sensitive to A. tamarii dose related inhibition was produced by homologous as well as 5 of the 12 heterologous species. Similarly, in A. terreus RAST inhibition was observed with homologous and A. tamarii extracts only. Our results suggested the presence of both species specific as well as shared allergenic components among different Aspergillus species. In TDIEP experiments using rabbit antisera to A. tamarii and A. terreus extracts multiple precipitin bands were observed with the homologous extracts. However, only 1-2 bands were produced by 6 heterologous Aspergillus species in each system. Collectively, these results gave evidence that there is heterogeneity of immune response in the patients with allergic respiratory diseases to different species of Aspergillus and also in rabbits immunized with Aspergillus extracts.

In vitro erythrocidal activity of activated spleen cells from young and old mice

We have recently reported that activated mouse spleen mononuclear cells (MNCs) efficiently lyse autologous erythrocytes in vitro (Saxena and Chandrasekhar, 2000). In the present study, we have investigated erythrocyte-depleting ability (EDA) of spleen MNCs from young and old mice. Time kinetics of survival of erythrocytes in mitogen-activated spleen cell cultures indicated that the erythrocyte depletion was significantly faster in young spleen cell cultures than in the old. Poorer EDA of old MNCs was in spite of the fact that the susceptibility to lysis actually increased in erythrocytes from old mice. Erythrocytes opsonized by a hamster anti mouse Fas monoclonal antibody, were destroyed with a much greater efficiency by young MNCs, whereas the corresponding effect of opsonization was only moderate for old MNCs. Depletion of macrophages from MNC preparations by plastic adherence as well as carbonyl-iron and magnet treatment had a marginal if any effect on EDA of young and old mouse MNCs, indicating that a lower lymphocyte-associated erythrocidal activity as one of the factors responsible for overall lower EDA associated with spleen derived MNCs of old mice.

A novel nonphagocytic mechanism of erythrocyte destruction involving direct cell-mediated cytotoxicity

The number of erythrocytes fell when co-cultured with cell preparations derived from mouse spleen, thymus, bone marrow, or peritoneal exudate (PE) cells. Erythrocyte-depletion activities (EDA) of different leukocyte preparations were in the order PE > spleen > thymus > bone marrow. Adherent, nonadherent, T-depleted, and T-enriched cell subpopulations had comparable EDA. Spleen cells from athymic nude mice, however, lacked significant EDA. In addition, EDA was boosted by Concanavalin A (Con A) but not by lipopolysaccharide, indicating that T cells may play a crucial role in inducing EDA in spleen cells. Paraformaldehyde-fixed spleen or PE cells, as well as membrane preparations isolated from spleen cells, efficiently lysed erythrocytes. Erythrocyte ghost membranes inhibited erythrocyte lysis by control or paraformaldehyde-fixed spleen cells. Treatment with hamster anti-mouse Fas or anti-mouse tumor necrosis factor receptor (TNFR) antibody could opsonize erythrocytes for faster depletion by spleen cells, suggesting an expression of Fas and TNFR on erythrocytes. TNF alpha could lyse erythrocytes in a dose-dependent fashion. Additionally, enhanced spleen cell EDA induced in response to succenyl Con-A could be blocked by anti-TNF alpha antibodies. Our results provide evidence for a direct cell-mediated cytotoxicity (CMC) of erythrocytes by leukocytes. A role of molecules of Fas and the TNF family in CMC of erythrocytes has also been suggested. Further work is needed to understand if, and to what extent, CMC of erythrocytes contributes to erythrocyte destruction in vivo and to determine its patho-physiological significance.

Effect of serum dilution in diagnosis of malaria in community

Recently, it has been shown that immunological methods can be used for the diagnosis of malaria other than sero-epidemiology. A study has been done to investigate optimum binding capacity of antigen-antibody (Ag-Ab) at different serum dilutions. For validating antigen-antibody (Ag-Ab) reaction at 1:100, 1:1000 and 1:1000 serum dilutions, have been tested in two different laboratories to establish validation of the ELISA method. Inter laboratory test on synthetic peptide (RI) ELISA was found comparable and meaningful for assessing malaria transmission in defined locality at 1:100 dilution. Results also showed that 1:1000 serum dilution can be useful for diagnostic purpose.

Alumina-supported synthesis of antibacterial quinolines using microwaves

7-(5'-Alkyl-1',3',4'-thiadiazol/oxadiazol-2'-ylthio)-6 -fluoro-2,4-dimethylquinolines and 3-formyl-2-(2'-hydroxy- 1',4'-naphthoquinon-3'-yl)-4-methyl/6-methyl/7-quinolines have been synthesised by the reaction of 5-alkyl-1,3,4-thiadiazol/oxadiazol-2-thiols with 7-chloro-6-fluoro-2,4-dimethylquinoline and by the reaction of 2-hydroxy-1,4-naphthoquinone with 2-chloro-3-formyl-4-methyl/6-methyl/7-methyl/8-methylquinolines respectively on basic alumina using microwaves, the reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating. The compounds were tested for their in vitro antibacterial activity. All compounds showed promising antibacterial activity. The best activity was observed by compounds 3a and 3f.

Upregulation of KIR expression on murine bone marrow cells by paraformaldehyde fixed tumor cells

We have previously shown that the activation of mouse spleen NK cells by IL2 is markedly boosted if paraformaldehyde fixed tumor target cells are added during the activation phase. In the present study, we have shown that such a boosting effect is not seen if mouse bone marrow (BM) cells are used instead of spleen cells. Addition of fixed tumor cells (1:100 ratio of tumor cells to BM cells) however resulted in a marked increase in the expression of Ly49 molecules on BM cells. The enhancement of Ly49 expression was not seen if fixed allogeneic BM cells were added, suggesting that Ly49 upregulation was tumor specific. Expression of Ly49A as well as Ly49C isotypes were augmented by fixed tumor cells. Moreover, increased Ly49 expression was seen on cell populations expressing TCRbeta as well as NK1.1 markers. These results indicate that exposure to tumor cells may be an important factor regulating KIR expression on NK and T cells. Implications of these results are discussed.

Cytolytic activity of mitogen activated old and young mouse spleen cells against tumor target cells expressing high or low levels of Fas antigen

Sensitivity of Fas expressing tumor cells (high levels in Hut78 & Jurkat; low levels in P815) toward the cytotoxic Con-A (5 microg/ml) activated spleen cells from young (12 to 16 week old males) and old (2 year old males) mice were studied. The spleen cells from young mice activated for a day showed high levels of cytotoxic activity against Hut78 and Jurkat cell lines but not against P815 cells. The cytotoxic activity against P815 cells were detected in the spleen cells from old but not young mice following a longer period of Con-A activation (three days). Comparable levels of cytotoxic activity against Hut78 and Jurkat cells were observed in the spleen cells from both young and old mice following three days of activation. Treatment of Hut78 cells with anti-Fas antibody affected the tumor cells become resistant against the cytotoxic activity of the spleen cells from young mice in a dose dependent manner however P815 cells were not affect by the anti-Fas antibody treatment. These results show that there are differences in the sensitivity of target tumor cells toward Con-A induced cytotoxic spleen cells from young and old mouse. Mitogen-induced cytotoxic lymphocytes from young mouse spleen appear to kill targets through mechanisms involving Fas antigen, specially, in early stage (1 day) of activation. Old mouse spleen cells generated high levels of cytotoxic cells in later phase (3 days), which appear to kill through Fas-unrelated mechanisms.

Sorption and desorption of cobalt by Oscillatoria anguistissima

Oscillatoria anguistissima rapidly adsorbs appreciable amounts of cobalt from the aqueous solutions within 15 min of initial contact with the metal solution. O. anguistissima showed a high sequestration of cobalt at low equilibrium concentrations, and it followed the Freundlich model of adsorption. The adsorption is a strongly pH-dependent and temperature-independent phenomenon. The presence of Mg2+ and Ca2+ (100-200 ppm) resulted in decline in Co2+ adsorption capacity of Oscillatoria biomass. Sulphate and nitrate (0. 75-10 mM) drastically reduced the extent of Co2+ biosorption. The biosorption of cobalt is an ion-exchange process as the Co2+ binding was accompanied by release of a large amounts of Mg2+ ions. Na2CO3 (1.0 mM) resulted in about 76% desorption of Co2+ from the loaded biomass.

Audiovestibular changes in diabetes mellitus

Audiovestibular functions in 50 cases of diabetes mellitus have been evaluated to find out the type of hearing loss. Diabetes mellitus causes a significant bilateral symmetrical hearing loss at higher frequencies and with the progress of disease and added complications the hearing further deteriorates. On control of diabetes hearing changes are found to be irreversible. However vestibular functions remain uninvolved in cases of diabetes mellitus. A direct correlation was found between hearing loss and increasing blood sugar level.

Induction of proliferation in resting B-cells by a factor released by activated mouse spleen cells

Mouse spleen cells activated in a mixed lymphocyte reaction release a soluble factor, which induces a significant proliferative response in fresh mouse spleen cells. This proliferation inducing factor (PIF) was found to be heat stable (90 degrees C for 45 min) and also resistant to trypsin or chymotrypsin treatment. By using a sizing HPLC column, the molecular weight of PIF appears to be 25 kDa. Mouse spleen cells treated with anti-thy-1 + complement lost Con-A induced proliferative responses but responded well to PIF. B cell depleted spleen cells obtained by negative selection panning, did not respond to PIF. These results indicate that B cells proliferated in response to PIF. Polymixin-B, which blocks the B cell proliferative response to LPS, did not inhibit PIF induced proliferation.

Purification and characterization of a regiospecific lipase from Aspergillus terreus

Aspergillus terreus lipase was purified to homogeneity with 18.0% yield. The specific activity of the enzyme increased from 20.80 to 250 U/mg of protein. Ion exchange on Q-Sepharose was highly effective in the purification process. The molecular mass of the purified enzyme was 41+/-1 kDa as determined by SDS/PAGE. The purified lipase showed excellent temperature tolerance (15-90 degreesC) and was highly thermostable, retaining 100% activity at 60 degreesC for 24 h. It showed good pH tolerance (3.0-12.0) and was stable over a pH range of 4.0-10.0 for 24 h. The activity of the enzyme was inhibited by ionic detergents, whereas non-ionic detergents stimulated enzyme activity. Mg2+ and Ca2+ ions stimulated lipase activity, whereas Co2+, Cu2+, Ni2+ and Fe3+ ions caused inhibition. The enzyme was unaffected by the metal chelator EDTA or by 2-mercaptoethanol and potassium ferrocyanide. At a concentration of 100 microM, 3,4-dichloroisocoumarin caused weak inhibition with 40% loss of activity, but diethyl p-nitrophenyl phosphate at the same concentration strongly inhibited enzyme activity (98.12% loss of activity), confirming that the A. terreus lipase is a serine hydrolase. The lipase was highly active on pig fat (151% relative activity) and groundnut oil (103% relative activity) and least active on kusum oil (18% relative activity). Extensive dialysis did not affect enzyme activity up to 168 h, suggesting the absence of any dialysable cofactor in the enzyme. The A. terreus lipase retained significant activity on freeze-drying and had a shelf-life of more than 6 months at room temperature. The A. terreus lipase exhibited 1,3-regiospecificity and was stable in various organic solvents.

Lipase production by Aspergillus and Penicillium species

Forty each of aspergilli and penicillia were screened for extracellular lipase production on agar plates and in liquid medium containing olive oil as substrate. Twenty-nine aspergilli and twenty-six penicillia produced lipase. Out of these, 19 aspergilli and 22 penicillia showed activity both on Nile blue sulfate and glycerol tributyrate agar plates while only 10 aspergilli and 4 penicillia showed a positive response to glycerol tributyrate agar alone. The screening revealed 11 Aspergillus spp. and 15 Penicillium spp. as new lipase producers. Pig fat as an economic substrate for lipase production was also investigated.

Tumor specific boosting of IL-2 induced NK activation by paraformaldehyde fixed tumor cells

NK activation in C57B1/6 mouse spleen cells was carried out with IL-2 in the presence or absence of paraformaldehyde fixed YAC tumor cells. Generation of anti-YAC cytolytic activity was markedly higher when activation was carried out in the presence of fixed tumor cells. In addition the cytotoxic effector cells generated were resistant to anti-Thy-1 + C treatment, indicating that the effector cells were not T lymphocytes. IL-2 activation of NK cells was compared When fixed YAC or EL4 tumor cells were added during the IL-2 activation phase, it was found that the addition of either of these tumor cells significantly boosted the levels of cytotoxic activity generated against both targets. Significantly higher anti-YAC cytotoxic activity was however generated when fixed YAC cells instead of EL4 cells were present during the activation phase. Similarly, significantly greater cytolytic activity was generated against EL4 cells, when fixed EL4 rather than YAC cells were present during the activation phase. Addition of paraformaldehyde fixed syngeneic or allogenic spleen cells instead of tumor cells, did not boost NK activation in response to IL-2, indicating that the boosting of NK activation did not result from exposure to alloantigens during the activation phase. These results indicate that an exposure to tumor cells during IL-2 activation phase, may boost the activation of NK cells in a tumor specific manner.

Potential use of a novel lipase from Aspergillus carneus in deacetylation reactions

A novel lipase from Aspergillus carneus has been used in organic solvents for efficient regioselective and chemoselective deacetylation of the peracetates of polyphenolic aromatic ketones, esters and amides. A reversal of regioselectivity was observed as compared with the results obtained during deacetylation with porcine pancreatic lipase (PPL).

Partial purification and characterization of a novel murine factor that augments the expression of class I MHC antigens on tumor cells

A soluble factor which augments the expression of major histocompatibility complex class I (MHC I) antigens on a number of murine tumor cell lines, has been isolated from the culture supernatants of mixed lymphocyte reaction of spleen cells derived from C57B1/6, Balb/c and Swiss mice. The factor, termed MHC-augmenting factor (MHC-AF) has been partially purified by Sephadex G-100 column chromatography and reverse phase HPLC. MHC-AF activity is associated with an 18 kDa molecule. MHC-AF activity was resistant to pH 2.0 treatment and partially purified MHC-AF preparations did not have any activity in L929 cell/vesicular stomatitis virus (VSV) interferon bioassay system. Antibodies to IFN-gamma did not block the activity of MHC-AF. These results indicate that a MHC-AF distinct from IFN-gamma, is produced by mouse spleen cells undergoing a mixed lymphocyte reaction.

Interplay of matrices in cartilage synovial fluid combine under moderate & high loadings

Interplay of the constituents of the articular cartilage synovial fluid combine and its role was examined through the biochemical and rheological studies on bovine joints. The results showed an inverse relationship between the changes in the hyaluronic acid of synovial fluid and the proteoglycans content in articular cartilage together with alterations in the rheological properties of synovial fluid. The study indicated that the inter-movement of fluid solutes across the cartilage and synovial fluid may have an important role in the pathophysiology of osteoarthritis.

Oscillatoria anguistissima: a promising Cu2+ biosorbent

Oscillatoria anguistissima rapidly adsorbs Cu2+ from aqueous solution. The adsorption of Cu2+ followed Freundlich Isotherm, and the amount of Cu2+ removed from solution increased with increasing Cu2+ concentration. The adsorption is pH dependent, and maximum Cu2+ removal occurs at pH 5. Of the various pretreatments, HCl treatment of the biomass increased the capacity for Cu2+ removal. Presence of Mg2+ and Ca2+ resulted in decline in the Cu2+ adsorption capacity of Oscillatoria cells. This species could also effectively remove Cu2+ from mine water containing 68.4 microg/ml of Cu2+ at pH 3.45.

Mechanism of interaction of pH 3.0 treated tumor cells expressing lower levels of class I MHC antigens, with IL-2 activated NK cells

Effect of lowering the levels of class I MHC antigens, on the ability of three murine (YAC, P815, SP2O) and three human (Molt4, Raji, HR7) tumor cell lines, to compete in cold target inhibition assays, was studied. Specific reduction in class I MHC levels (range 60-76%) was induced by brief exposure to citrate buffer (pH 3.0). Susceptibility of the acid pH treated tumor cells to lysis by IL-2 activated NK cells, was found to be significantly increased in all cases with the exception of YAC cells. Reduction in class I MHC antigen expression by acid pH treatment, had no significant effect on competing ability of the tumor cells. In contrast, tumor cells on which MHC class I antigens were upregulated by interferon treatment, had significantly lower ability to compete. These results suggest that the mechanisms of altered interactions between MHC I up or down regulated target cells may be different. A model compatible with increased NK susceptibility along with an unaltered ability to compete for acid pH treated tumor cells, has been proposed.

Microorganisms as an alternative source of protein

Demand for human food and animal feed proteins from nonconventional sources has increased, particularly in developing countries. Microbial protein is one such source. It is desirable because it is amenable to controlled intensive cultivation and is less dependent on variations in climate, weather, and soil. Microbial proteins must be evaluated for nutritive value, safety, and economic considerations before mass production is undertaken.