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Biomedical subjects

A Ferrante

Publications and source records attributed to A Ferrante.

At least 235 records · Page 13Linked to original sources
PubMed1982

Comparative sensitivity of Naegleria fowleri to amphotericin B and amphotericin B methyl ester.

Data presented showed that Naegleria fowleri is much more sensitive to amphotericin B (AmB) than to amphotericin B methyl ester (AME). In vitro, AME was effective at concentrations of 1.0 microgram/ml whereas the parent antibiotic, AmB, was effective at concentrations of 0.0125 to 0.025 microgram/ml. In vivo, AmB, at a concentration of 2.5 mg/kg/day, produced 100% survival in mice infected with N. fowleri, but AME failed to protect infected mice even at concentrations of 30 mg/kg/day. The results support previous observations with fungi which have shown that AmB is a more potent antimicrobial agent than AME.

Amoeba↗
PubMed1982

The chemotherapeutic value of sulphadiazine in treatment of Acanthamoeba meningoencephalitis in mice.

The chemotherapeutic value of three sulphonamides, sulphamethizole, sulphamethoxazole and sulphadiazine, was examined in experimental Acanthamoeba meningoencephalitis in mice. Only sulphadiazine was capable of protecting mice challenged with A. culbertsoni A-1 strain. However, protection to mice was only afforded if the drug was given early after infection. Once the amoebae reached, and became established in, the central nervous system, sulphadiazine displayed no chemotherapeutic value.

Amebiasis↗
PubMed1982

Inhibition of serum bactericidal activity by bilirubin.

The results presented show that bilirubin inhibited the bactericidal activity of human serum. Addition of serum albumin (which tightly binds bilirubin) to the bactericidal assay prevented the inhibition mediated by bilirubin. These findings suggest that the decreased bactericidal activity of sera from neonates with hyperbilirubinemia may be due to the inhibition of the bactericidal activity by unconjugated bilirubin.

Bilirubin↗
PubMed1982

Polyamine oxidase-mediated killing of African trypanosomes.

African trypanosomes, Trypanosoma brucei brucei, T. vivax and T. congolense, were killed when incubated in vitro with ruminant sera in the presence of exogeneous spermidine, and were non-infective for mice. Purified polyamine oxidase in the presence of spermidine-mediated similar killing of trypanosomes. The abundance of polyamine oxidase activity in ruminant sera which can react with polyamines to produce products with cytotoxic properties may explain the trypanosome killing. This system may contribute to non-specific parasite killing in vivo.

Animals↗
PubMed1982

Immune dysfunction in the presence of residual splenic tissue.

Immunological function was examined in children who had undergone splenectomy, in 8 for trauma, and in 11 for haematologic/oncologic reasons. Particular emphasis was placed on the effects of residual splenic tissue on immune function. Children in the elective group had no evidence of splenosis but 6 of the 8 trauma patients showed residual splenic activity. A general trend indicated that immunological dysfunction was associated with the presence of residual splenic tissue. Three patients with significant post-traumatic splenosis showed low IgM levels, one also had a low IgG level and another a low IgA and impaired lymphocyte response to mitogens. The trauma patients with little or no splenic tissue had normal immune functions. Immunological abnormalities were found in 8 of the 11 haematologic/oncologic patients with no splenosis suggesting the abnormalities were possibly due to the primary disease. In contrast to the popular belief that splenosis confers protection against overwhelming sepsis, the present findings suggest that patients with residual splenic tissue are at a greater risk of infection because of a lower level of immune response.

Adolescent↗
PubMed1982

Inhibition of mitogen-induced human lymphocyte responsiveness by polymixin antibiotics.

Polymixin antibiotics, polymixin B and polymixin E (colistin) inhibited the mitogen-induced lymphoproliferative response of human lymphocytes. Inhibition of the lymphocyte response to PHA, PWM and Con A was evident at a low concentration of 1 U/ml of antibiotics. Lymphocytes in which the signals for proliferation had occurred were similarly prevented from proliferating. The effects were not due to cell death (toxicity). Since polymixin concentrations at which inhibition of lymphocyte proliferation was observed are employed in tissue culture medium and are also attained in plasma of patients, the results suggest that the use of the antibiotics in lymphocyte cultures limits lymphocyte responsiveness and that patients receiving polymixin antibiotics may experience a state of immunosuppression.

Colistin↗
PubMed1982

Rapid single-step method for purification of polymorphonuclear leucocytes from blood of patients with rheumatoid arthritis.

Previous studies have shown that blood samples from healthy subjects and patients with a variety of different diseases separate into distinct mononuclear leucocyte (MNL) and polymorphonuclear leucocyte (PMNL) bands when centrifuged on a Ficoll-Hypaque medium of density 1.114 g/ml. Results from the present study showed that blood samples from patients with rheumatoid arthritis (RA) failed to separate into discrete cellular fractions under the same conditions. In particular, the PMNL were not recoverable because the erythrocytes only partially sedimented. However, following modification of the separation medium involving (a) reduction in the final Ficoll concentration from 8% to 7%, and (b) an alteration in the ratio of meglumine Hypaque:sodium Hypaque from 5.7:2.8 to 2.0:7.5, a clear band of PMNL of high purity could be obtained with blood samples from patients with RA. The modification of this previously described, simple, brief, one-step, density gradient centrifugation method achieved separation of peripheral blood PMNL required for studies of leucocyte function in patients with RA.

Arthritis, Rheumatoid↗
PubMed1980

Induction of suppressor cells in mice following Vaccinia virus infection.

Infection of mice with Vaccinia virus produced suppression of responsiveness of spleen cells to mitogens in vitro and suppression of delayed-type hypersensitivity in vivo. The latter suppression was transferred to normal mice by spleen cells of virus-infected mice. The data presented show that Vaccinia virus-induced immunosuppression involves the induction of suppressor cells which belong to both the adherent and non-adherent cell fractions.

Animals↗
PubMed1980

Optimal conditions for simultaneous purification of mononuclear and polymorphonuclear leucocytes from human blood by the Hypaque-Ficoll method.

Data on the optimal conditions for the simultaneous purification of mononuclear (MN) and polymorphonuclear (PMN) leucocytes from human blood on Hypaque-Ficoll medium of one density is presented. The efficiency of separation of MN and PMN leucocytes by the Hypaque-Ficoll method was dependent on both the Ficoll concentration and the density of the medium. Best results were obtained with a medium consisting of a Ficoll concentration of 8.2% and a density of 1.114 g/ml. The separation procedure was much more efficient if carried out at room temperature than at 4 degrees C. Storing human blood markedly affected the efficiency of separation and best results were obtained using fresh blood. Data are also presented on the variability in the separation with respect to 40 adults and 80 children.

Adult↗
PubMed1980

Simultaneous preparation of mononuclear and polymorphonuclear leucocytes from horse blood on Ficoll-Hypaque medium.

Results presented show that highly purified populations of mononuclear (MN) and polymorphonuclear (PMN) leucocytes can be obtained from horse blood by a procedure similar to that previously described for the separation of these leucocytes from human blood. This involved centrifugation of horse blood on a Ficoll-Hypaque medium with a density of 1.095 g/ml. The procedure required approximately 1 h for completion and resulted in the simultaneous preparation of MN (greater than 98% purity) and PMN (greater than 96% purity) leucocytes. Cell viability exceeded 95% and cells retained immunological functions.

Animals↗
PubMed1980

Activation of complement by Naegleria.

Neither Naegleria nor its culture supernatant was found to be directly chemotactic for human neutrophils. Interaction of Naegleria with human serum, however, resulted in the generation of a strong chemotactic stimulus. The reduction of serum activity by heat-inactivation indicated a dependence on serum complement for the interaction. The ability of Naegleria to activate the alternative complement pathway was demonstrated with the use of C2-deficient serum.

Amoeba↗
PubMed1980

Immunization with live amoebae, amoebic lysate and culture supernatant in experimental Naegleria meningoencephalitis.

Immunization with two doses of live Naegleria fowleri produced a survival of 34% of mice compared to 0% in unimmunized controls, whereas multiple doses of live N. fowleri resulted in loss of protective immunity. In contrast, multiple doses of N. fowleri lysate produced a survival of 30%, and multiple doses of N. fowleri culture supernatant produced a survival of 67 to 78%. Fractionation of the culture supernatant by column chromatography showed that all six fractions contained protective antigens, but the best protection occurred from immunization with the high molecular weight fraction (greater than 200,000 daltons).

Amebiasis↗
PubMed1980

Effect of tetracycline treatment on immunological responses in mice.

Mice treated with tetracycline have reduced capacity to mount delayed-type hypersensitivity (DHT) responses to sheep erythrocytes. The suppressive effect of DTH was more pronounced when the drug was given at the time of challenge with sheep erythrocytes. The in vivo chemotaxis of macrophages was also depressed in mice given tetracycline. There was, however, no significant suppression of antibody production to sheep erythrocytes.

Animals↗
PubMed1980

Immunopotentiation by pyrimethamine in the mouse.

Pyrimethamine, a 2,4-diaminopyrimidine useful in the treatment of malaria and toxoplasmosis, was found to enhance antibody and delayed-type hypersensitivity responses to sheep red cells in mice. The immunodepression of tumour-bearing mice was also reversed by pyrimethamine. This drug may prove useful as a general immunostimulant in clinical situations where the immune system has been compromised by cancer or other debilitating illnesses.

Adjuvants, Immunologic↗