Corrosion resistance of aluminum against acid activation in 1.0 M HCl by symmetrical ball - type zinc phthalocyanine.

The inhibition effect of symmetrical Ball - type Zinc Phthalocyanine on Aluminum in 1mol/L hydrochloric acid was analyzed by electrochemical techniques. A novel ball-type zinc phthalocyanine (Zn-Pc) inhibitor has been synthesized and verified utilizing FTIR, nuclear magnetic resonance (1H NMR and 13C NMR), MALDI-TOF MS, and absorption spectroscopy (UV-Vis). In addition, laser-induced breakdown and photoluminescence spectroscopy were employed for additional study. Weight loss technique was employed to investigate the corrosion inhibition effectiveness of the synthesized Zn-Pc on Aluminum in 1mol/L hydrochloric acid at the range of variation temperatures (293-333 K). The inhibition efficiency of Zn-Pc increased with higher concentrations of Zn-Pc and decreased as the temperature increased. Furthermore, Zn-Pc demonstrated outstanding outcomes, achieving 72.9% at a very low inhibitor concentration (0.4 mmol/L) at 298 K. The experimental data for Zn-Pc Aluminum in 1mol/L hydrochloric acid obeys the Langmuir adsorption isotherm. Moreover, the corrosion system's thermodynamic parameters and activation energy were determined. Quantum chemical calculations applying the (DFT) Density Functional Theory method was conducted and applied in this study. These calculations played a pivotal role in elucidating molecular structures and reactivity patterns. Through DFT, numerous reactivity indicators were computed, providing valuable insights into the chemical behavior of the studied compounds. These indicators, such as frontier molecular orbitals, electron density, and molecular electrostatic potential, were subsequently correlated with experimental data.

Nasopharyngeal Salivary Gland Anlage Tumour: A rare cause of neonatal respiratory distress.

A salivary gland anlage tumour (SGAT) is a very rare type of benign tumour that usually presents in early infancy with respiratory distress which is exacerbated upon feeding. We report a full-term male neonate who was referred to the Al Nahdha Hospital, Muscat, Oman, in 2015 with severe neonatal respiratory distress due to a nasopharyngeal obstruction immediately after birth. Computed tomography and magnetic resonance imaging revealed a well-circumscribed mass in the nasopharynx, without intracranial extension. Histopathological analysis of the lesion confirmed a diagnosis of SGAT. Following excision of the tumour, the postoperative period was uneventful. No recurrence was observed over the next two years. This case report highlights the importance of the early recognition of this extremely rare and potentially life-threatening, yet easily curable, condition.

Antitumor activity of bacteriophages in murine experimental cancer models caused possibly by inhibition of beta3 integrin signaling pathway.

Bacteriophages (phages) as bacterial viruses are generally believed to have no intrinsic tropism for mammalian cells. In this study the interactions between phages and various eukaryotic cells were investigated. Binding of phages to the membranes of cancer and normal blood cells was observed. Moreover, it was shown that the wild-type phage T4 (wtT4) and its substrain HAP1 with enhanced affinity for melanoma cells inhibit markedly and significantly experimental lung metastasis of murine B16 melanoma cells by 47% and 80%, respectively. A possible molecular mechanism of these effects, namely a specific interaction between the Lys-Gly-Asp motif of the phage protein 24 and beta3-integrin receptors on target cells is proposed. It was also shown that anti-beta3 antibodies and synthetic peptides mimicking natural beta3 ligands inhibit the phage binding to cancer cells. This is in line with the well-described beta3 integrin-dependent mechanism of tumor metastasis. It is concluded that the blocking of beta3 integrins by phage preparations results in a significant decrease in tumor invasiveness.

CEA-related proteins on human urothelial cell lines of different transformation grades.

CEA family proteins from human urothelial cell lines of different transformation grades were characterized by flow cytometry and Western blotting using monoclonal antibodies: 26/3/13, D14HD11, 9A6 and 4/3/17. The following observations were made: (i) the urothelial cell lines, representing transformation grade III (TGr III, tumorigenic, invasive cells), were characterized by the presence of a component with molecular mass 110-135 kDa, most probably representing biliary glycoprotein (BGP); (ii) BGP was absent in non-tumorigenic and non-invasive TGr II urothelial cell lines; (iii) a protein band with apparent molecular mass 180 kDa, and migrating as a CEA standard was detected in only one of seven urothelial cell lines analyzed; (iv) a broad band of apparent molecular mass migrating at 65-90 kDa, probably representing NCA-50/90, was found in two tumorigenic and invasive cell lines, HCV 29T and Hu 1703He.

Cytotoxicity and proliferation of splenocytes and lymph node cells from adjuvant-treated nude mice. Studies of natural and in vitro activation.

The cytotoxicity of NK cells and lymphocytes derived from nonadherent splenocytes (SPL) and regional lymph node cells (LNC) from complete Freund's adjuvant (CFA)-treated athymic nude young (4-6 weeks) and aged (over 1 year) BALB/c nu/nu mice in vitro activated with rIL-2, anti-CD3 mAb or PPD was analyzed and compared to SPL and LNC from age-matched euthymic BALB/c mice. The high natural cytotoxicity to YAC-1 target cells of SPL or LNC could be augmented by 48 h stimulation in vitro with rIL-2, especially when derived from young nude BALB/c mice. The increase in cytotoxic activity was accompanied by increased proliferative activity of both SPL and LNC, which showed statistically significant differences between the rates of stimulation of cells from the young and aged groups. Anti-CD3 mAb strongly activated the cytotoxicity of BALB/c euthymic donor effector cells against P-815 target cells, corresponding to a very high proliferative activity of these cells, but anti-CD3 mAb did not lead to activation of effector cells from nude donors. FACS analyses of antigenic markers similarly showed an increased number of T cells in LNC from aged BALB/c nude donors, which, however, never reached the levels of those of euthymic animals.

Growth inhibition of transplantable tumors in mice by mIL-2-secreting murine plasmocytoma cells used alone or in combination with a cytostatic agent.

The non-tumorigenic cells of X63-Ag8.653 mouse plasmocytoma line transfected with murine interleukin 2 cDNA (X63-mIL-2) served us as the source of the cytokine to induce or to augment antitumor response in syngeneic BALB/c or semisyngeneic (CD2F1) mice challenged subcutaneously with either "wild" line tumor cells (X63/0) or with non-related methylcholantrene induced BFS1 fibrosarcoma of BALB/c mice. When applied peritumorally in several injections (2 to 6) to mice with non-advanced stages of the tumors, IL-2-secreting cells were able to cause tumor growth retardation in most of the treated mice and to induce tumor rejection in some of them. The combination chemoimmunotherapy was attempted in mice with advanced BFS1 fibrosarcoma using compound CBM-4A (the bromoanalog of ifosfamide) administered at various time (4 h or 3, 5 or 7 days) before the first of two local injections of transfected cells. The strategy proved to be more efficient in the tumor growth inhibition as compared with the cytostatic alone.

Effect of peritoneal cells on tumors cells growth in vitro.

The cytotoxic and cytostatic activity of PMA-treated macrophages, obtained from pristane-primed BALB/c mice, was analyzed in vitro. The activated macrophages were cytotoxic and cytostatic for YAC-1 lymphoma, P-388 leukemia and P-815 mastocytoma target cells. However, the RPC-5 plasmacytoma target cells appeared to be resistant to their cytotoxicity. The observed cytotoxic or cytostatic effects of macrophages in vitro were not correlated with their ability to produce the superoxide ion. Cytotoxic activity of NK cells, obtained from pristane-primed mice, was also studied. No differences in cytotoxicity of NK cells obtained from pristane-treated and untreated donors, were found. However, only the effector cells from untreated mice were able to respond to stimulatory effect of polyinosinic acid-polycytidylic acid-poly-L-lysine (poly ICLC).

The effect of adherent peritoneal exudate cells (APECs) and their products on the RPC-5 plasmacytoma growth in vitro.

The ability of peritoneal exudate cells (PECs) and their adherent (APECs) and nonadherent (NAPECs) fractions to enhance RPC-5 plasmacytoma growth in vitro was studied. The capability of these cells to bind RPC-5 cells and influence of the binding on cytolysis tumor cells by activated with C. parvum macrophages was also determined. The effector cells were harvested from mice injected i.p. with pristane, thioglicollate medium or C. parvum or from intact mice. The effect of supernatants from the in vitro cultured PECs, APECs or NAPECs on growth RPC-5 cells were also tested. It was found that the RPC-5 plasmacytoma growth was enhanced only by cells obtained from mice treated with pristane, or by supernatants from cultured PECs and APECs derived from pristane treated mice. The adherent cells from pristane treated mice were able to bind tumor cells. The tumor cells preexposed to adherent cells from pristane stimulated mice were resistant to lysis by activated with C. parvum macrophages.

The effect of adherent peritoneal exudate cells on plasmacytoma growth in BALB/c mice.

The effect of adherent peritoneal exudate cells (APECs) from pristane treated and intact mice was studied by Winn's test. The experiments were performed with the use of plasmacytoma cell lines TEPC-15f, MP-26 and five primary lines. The studies showed that APECs from mice exposed to treatment with pristane were able to stimulate growth of both TEPC-15f and MP-26 plasmacytoma. The primary plasmacytoma lines adapted to intraperitoneal growth more easily in the presence of adherent cells than when they were given alone.

Specific killing of mouse leukemic cells with ricin A-chain immunotoxin.

Monoclonal IgM antibody against L1210V leukemia was coupled with ricin A-chain using N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) as a cross--linking agent. The coniugate had potent concentration--dependent cytotoxicity against L1210V, L1210 and RL male 1 cells being completely non toxic to EL-4, P388, RPC-5 and mouse bone marrow cells. The minimum time required for killing L120V leukemia cells was 30h of in vitro exposure, at a concentration 10(-6) M (as assessed by trypan blue test). However, 1h contact of L1210V cells with immunotoxin was sufficient to completely inhibit proliferation of leukemic cells subsequently inoculated into compatible mice. The toxicity could be potentiated by addition of NH4Cl, that shortened minimum exposure time to 18h and 45 min respectively.

Biological properties of human tissue-type plasminogen activator obtained by expression of recombinant DNA in mammalian cells.

Human tissue-type plasminogen activator (t-PA), obtained by expression in mammalian cells of recombinant DNA coding for the entire sequence of t-PA (rt-PA), was compared with natural activator from melanoma cell culture (mt-PA). In an in vitro system, composed of [125I]fibrinogen-labeled plasma clot suspended in circulating human plasma, rt-PA and mt-PA caused a very similar dose-related degree of fibrinolysis without causing extensive fibrinolytic activation and fibrinogen breakdown in the surrounding plasma. Urokinase only induced fibrinolysis at a 5- to 10-fold higher concentration and in association with extensive fibrinogenolysis. Intravenous injection of mixtures of labeled (0.4 microCi/kg) and unlabeled (2000 I.U./kg) mt-PA or rt-PA resulted in a rapid but similar disappearance of activity from plasma (T1/2 of 3 min) and specific accumulation of tracer in the liver. In rabbits with experimental jugular vein thrombosis, rt-PA and mt-PA caused a very similar dose-dependent thrombolysis without causing substantial systemic activation of the fibrinolytic system and fibrinogenolysis. Urokinase induced significant thrombolysis only at a 10-fold higher dose and this was associated with systemic fibrinolytic activation. Infusion of 96,000 I.U./kg (approximately equal to 1 mg/kg) of mt-PA or rt-PA over 4 hr induced approximately 70% lysis, whereas a 10-fold higher dose of urokinase yielded 35 to 40% lysis. Two subfractions of rt-PA differing in the extent of glycosylation had very similar thrombolytic properties. It is concluded that the potentially more readily available rt-PA could constitute a specific, fibrin-selective thrombolytic agent.

Cell surface antigens of L-1210 leukemia recognized by monoclonal antibodies.

Conventional antisera to L-1210 leukemia were being prepared in our laboratory for nearly a decade and consistently the only specificity detectable was anti Mammary Leukemia antigen (ML). Serological analysis of five monoclonal antibodies obtained following the same immunization schedule showed more diverse pattern of reactivity. Two antigens detected belong to oncofetal category. The third one is differentiation antigen Ly-6 and the nature of two others, expressed on leukemic cells only, remains at present unclear. Thus none of the clones analysed produces antibodies to ML antigen. Our previous analysis of cell surface antigens of L-1210 leukemia with the use of conventional antisera has already been described. This paper presents the results of applying monoclonal antibodies in a comparable studies.

Experimental plasmacytoma in mice. II. Qualitative studies of myeloma proteins.

Qualitative studies on paraproteins present in ascites and/or in serum of mice with induced plasmacytoma were performed by the method of immunoelectrophoresis. Myeloma proteins were found in 75 out of 116 plasmacytomas. Among them in 53 cases production of IgA, in 6-IgG3, and in 1 case IgG was detected. In 10 out of 75 samples, two paraproteins present in one ascites were detected.

Experimental plasmacytoma in mice. I. Induction, morphological and biological characteristics.

The induction of plasmacytomas in BALB/c mice by Bayol F or Pristan is described. In some experiments mice treated with Bayol F were antigenically stimulated by repeated injections of allogenic C57BL/6 spleen cells. The incidence of plasmacytoma was 57% in Bayol F treated mice and 59% in the mice subjected to sustained antigenic stimulation. However, the tumors appeared about 6 months earlier in mice stimulated with the allogeneic spleen cells.

Cytostatic activity in vitro of cycloleucine, aspartic acid and glutamic acid phosphonic analogues.

Cytostatic activity of 18 new phosphonic acid derivatives of cycloleucine, aspartic acid and glutamic acid was tested against human KB and mouse L1210s leukemia cell lines in vitro. The tests were performed according to international protocol 1.600 for screening of chemical agents against tissue culture system. Four of the tested compounds revealed their cytostatic activity at the dose 10 micrograms/ml.