Inhibitory effect of antibodies against human chorionic gonadotropin on the growth of colorectal tumour cells.

Human chorionic gonadotropin (hCG) was initially believed to be secreted exclusively by the embryo with its primary function being “rescue” of the corpus luteum. However, recently it has been found that the hormone (or its individual subunits) is also secreted by many cancers and that in many cases secretion is associated with poor patient prognosis. In this study, we assessed the presence of hCG in colorectal cancer cells (CCL-253) and evaluated the anti-tumour effects of anti-hCG antibodies in vitro and in vivo. Anti-hCG antibodies were reactive with CCL-253, as revealed by confocal immunoflourescence microscopy; both cell surface and intracellular expression were observed. Western blot analysis showed that antibodies appeared to interact with several moieties, indicating a level of cross-reactivity. Anti-hCG antiserum specifically reduced the viability of tumor cells and the addition of complement increased in vitro anti-tumor effects. In nude mice implanted with CCL-253 cells, administration of anti-hCG antiserum caused a significant reduction in tumor volume; all treated animals survived, while mortality was observed in control animals. Results suggest that anti-hCG antibodies can mediate significant anti-tumor activity both in vitro and in vivo and lend support to the rationale of anti-hCG immunization in the therapy of gonadotropin- sensitive cancers.

Considerations on the effect of anti-sandfly antibodies on biological parameters of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae)

A imunização de hospedeiros vertebrados com componentes derivados de vetores pode se constituir numa estratégia alternativa para o controle de doenças transmitidas por insetos. No presente estudo avaliamos o efeito de anticorpos antiflebótomos sobre alguns parâmetros biológicos de fêmeas de Lutzomyia longipalpis, vetor de leishmaniose visceral. Coelhos foram imunizados com extratos de tubos digestivos de fêmeas alimentadas com açúcar (GS), fêmeas alimentadas com sangue (GB), carcaças de fêmeas alimentadas com açúcar (CS) ou carcaças de fêmeas alimentadas com sangue (CB), e coelho imunizado por repetidas picadas de fêmeas de flebótomos (BITE). Os soros imunes de coelhos apresentaram títulos aumentados quando comparados com os soros pré-imunes, e bandas específicas foram detectadas por meio de Western Blot. A análise dos parâmetros biológicos revelou um decréscimo na fecundidade no grupo de fêmeas alimentadas em coelho imunizado com GB e BITE. A longevidade e a mortalidade foram estudadas em fêmeas com postura (paridas) e fêmeas sem postura (nulíparas). Fêmeas nulíparas que se alimentaram em coelho imunizado por repetidas picadas morreram em maior percentual. A análise da mortalidade, após a postura dos ovos, revelou um pico no quinto dia em todos os grupos, mas em fêmeas que se alimentaram em coelho submetido a repetidas picadas, foi antecipada para o terceiro dia.

Cellular mechanism of heart injury in the early stage of crush injury in rats / 法医学杂志

OBJECTIVE@#To study cellular mechanism of cardiomyocytes injury in the early stage of crush injury by observing some effects of crush injury rat sera on cultured neonatal rat cardiomyocytes.@*METHODS@#One to three days old neonatal rat cardiomyocytes were cultured in vitro and some effects of crush injury rat sera on beating rate, cell surface area, total protein content, 3H-Leu incorporation, intracellular calcium concentration ([Ca2+]i) and Fos protein expression were observed in cultured rat cardiomyocytes.@*RESULTS@#Compared with normal rat serum group, crush injury rat sera decreased beating rate(beats/min) of cardiomyocytes from 88.3 to 26.4, cell surface area, total protein content, 3H-Leu incorporation, [Ca2+]i (nmol/L) and PI of Fos protein expression were increased.@*CONCLUSION@#Crush injury rat sera suppress cell beating, increase intracellular calcium, induce Fos protein synthesis and cause cell hypertrophy, which may cause cardiac injury in the early stage of rush injury.

Mechanism of enhancement of renal (Na+ + K+) ATPase activity following chronic ethanol exposure

A method was devised to determine the nature of the mechanism of the increase in renal (NA++K+)-ATPase in rats fed dilute ethanol for ten weeks. Antiserum to (NA++K+)-ATPase obtained from rabbits was added to microssomal fractions of Kidney and the activities of (NA++K+)-ATPase and Mg2+ ATPase were determined. The addition of antiserum resulted in a same pattern of dose-related inhibition of (NA++K+)-ATPase activity in control and ethanol-fed rats, whereas mg2+-ATPase was not affected by the antiserum. These results suggest that the mechanism of ethanol-induced enhancement of renal (NA++K+)-ATPase activity could be explained through an increase in the number of catalytic units.

A rapid method to evaluate the bactericidal activity of hiperimmune serum against Vibrio cholerae 01 using oxidase test

Desenvolveu-se ensaio rapido para medir o efeito de soros imunes contra o Vibrio cholerae 01, tendo-se por base a atividade de oxidase de culturas de bacterias em placas de ELISA

Termination of pregnancy in mice following antiserum administration to modified chicken riboflavin carrier protein.

Rabbit antibodies to native riboflavin carrier protein (RCP), are to a large extent directed towards conformational epitopes and antibodies to disulphide bond reduced carboxymethylated RCP (RCM-RCP) are towards sequential epitopes. The major cyanogen bromide (CNBr) fragments and tryptic fragments of RCM-RCP interact with both antiserum to RCM-RCP and RCP. Passive immunization of pregnant mice with antibodies to RCM-RCP results in bioneutralization, leading to termination of pregnancy. Recently, a major tryptic fragment of RCM-RCP (24 +/- 2 kd) which could assume conformation at the antibody combining site of native RCP, obtained following mild trypsinization has been identified [Natraj et al. J. Biosci, 15 (1990) 341]. Rabbit antibodies to RCM-RCP treated with trypsin generated antibodies of low titer which interacted with RCM-RCP as well as RCP. The interaction of this antibody with RCP was of high affinity and could be displaced with RCP. The bioneutralizing ability of the antibody was demonstrated by its ability to cause termination of pregnancy in mice.

Phagocytosis of enteropathogenic Escherichia coli and Candida albicans by lectin-like receptors

1. Ingestion of enteropathogenic Escherichia coli or Candida albicans by thioglycollate-elicited macrophages and polymorphonuclear leukocytes was investigated in vitro, 2. Goat antiserum against mannose receptors caused about 50% inhibition of E. coli phagocytosis and about 90% inhibition of C. albicans phagocytosis. 3. E. coli and C. albicans uptake was inhibited by about 60% and 98%, respectively, by plating the macrophages onto substrates coated with poly-L-lysine-mannan. Further addition of 50 mM mannose to the medium significantly increased the inhibition of phagocytosis of E. coli by macrophages from 60.7 +/- 1.5 to 79.8 +/- 13.1 and by polymorphonuclear cells from 58.9 +/- 3.7 to 88.7 +/- 4.9. 4. Preincubation of phagocytic cells with antiserum against substance A of human erythrocytes reduced E. coli ingestion by 95%, but this inhibition was not observed when the antiserum was incubated with N-acetylgalactosamine (50 mM) before being added to the phagocytes. The phagocytosis of C. albicans was not inhibited by anti-substance A antiserum. 5. The phagocytosis of E. coli was inhibited by about 25% by the addition of 7.8 micrograms/ml soluble mannan to the medium, and by about 50% by the addition of 50 mMN-acetylgalactosamine; when both substances were added to the medium, an additive inhibition of about 75% was observed. 6. These results indicate that mannose receptors on the surface of phagocytic cells mediate E. coli or Candida albicans uptake and that the binding of bacteria to N-acetylgalactosamine residues from the membrane of phagocytes is also involved in the phagocytosis of E. coli

The Enhancing Effect of Ethanol on the Development of Glutatione S-Transferase Placental Form-Positive Foci Induced by Diethylnitrosamine in F344 Rat

The effects of ethyl alcohol and pig serum administration on the development of preneoplastic hepatic enzyme-altered foci were examined in an in vivo mid-term assay system. Rats were initially given a single dose (200 mg/Kg) intraperitoneal injection of diethylnitrosamine (DEN). Two weeks later, treatment was started with 10% ethanol + 10% sucrose solution, 10% sucrose solution, or tap water as drinking water for 6 weeks with or without intraperitoneal injection of porcine serum twice a week. All rats were subjected to a two-thirds partial hepatectomy at week 3. The modification potentials were evaluated by comparing the number and area per cm2 of glutathione S-transferase placental form-positive (GST-P+) foci in the liver of each group. As a result, ethanol significantly enhanced the development of GST-P+ foci. Unfortunately, the porcine serum injection produced no hepatic fibrosis and no significant alteration in GST-P+ foci.

Mechanism of complement-independent and antibody-mediated killing of Leishmania donovani promastigotes.

Immune serum raised against flagellar fraction of Leishmania donovani isolate UR6 has profound lethal effect on the in vitro growth of the parasite. Lethal effect of immune serum was also examined using two other isolates of L. donovani, namely DD8 and AG83. It was observed that immune serum is equally effective against UR6 and DD8 but has no effect on AG83 promastigotes. Parasite killing is mediated by Leishmania-specific antibodies in the absence of complement or any other factors present in rabbit serum. Results indicate that the lethal effect of immune serum is due to impairment in membrane function leading to inhibition in uptake of essential nutrients needed for growth and survival of parasites.

Estandarización y evaluación de un enzimoinmunoensayo para diagnóstico y seroepidemiologia de triquinosis humana / Standardization and evaluation of an immunoenzyme assay for diagnosis and seroepidemiology of human trichinosis

Se estandarizó un enzimoinmunoensayo (EIE) en fase sólida en el que se empleó un antígeno solubre total de T. spiralis y una dilución única de suero, y se evaluó la capacidad del sistema para detectar anticuerpos totales antitriquina con fines diagnósticos y seroepidemiológicos. Las curvas dosis respuesta mostraron que trabajando con una dilución de suero de 1:100 se obtenía una buena diferenciación entre sueros de individuos no infectados y pacientes de triquinosis con baja concentración de anticuerpos circulantes y la respuesta fue lineal entre valores de 0.15 y 0.64 unidades de densidad óptica (DO). El estudio de 720 sueros de población general no infectada reveló una X=0.07 y una S=0.03 unidades de DO. El 98,61% de esta población presentó valores de DO < X + 3S; el 1,25% valores dom DO entre > ou = X + 3S y < X + 4S; y el 0.14% restante valores entre > ou =X + 4S y < X + 5S. Se empleó un valor de DO = X + 5S como nivel diagnóstico para estudiar 4 brotes de triquinosis humana, 80 sueros de pacientes de triquinosis con diferentes títulos en inmunofluorescencia indireta (IFI) y 20 sueros de pacientes de hidatidosis. El EIE propuesto permitió diferenciar en forma confiable y eficiente población infectada de no infectada y tuvo una buena correlación con la IFI. Todos los sueros de pacientes hidatídicos presentaron valores de DO < X + 4S

An Experimental Study on Immune Complex Induced Athritis in Rabbits: Reference to Macrophages and M-type Cells of the Synovium

This study evaluates the pathogenesis of rheumatoid arthritis by producing immune complex induced arthritis with an intra-articular injection of BSA in immunized rabbits, and the effect of systemic administration of cyclophosphamide and local administration of anti-macrophage serum. The reduction of inflammatory reaction by cyclophosphamide administration appears to be caused mainly by selective depletion of the neutrophils, and partly by immune suppression. It appears that the rabbit abdominal macrophage has the common morphologic, functional and antigenic patterns with the M-type synovial lining cells. There is another possibility that the cross-reacting antigens between macrophage and the M-type cell of the synovial lining may exist. It is concluded that in this experimental immune complex arthritis, the site of localization of immune complexes seems to be the synovial, M-type cell, and the tissue injury of synovium is largely mediated not only by neutrophils and complement, but also by macrophages.

Protection against scrub typhus infection engendered by the passive transfer of immune sera.

The passive transfer of convalescent sera did not protect the majority of mice against challenge with the homologous strain and was completely ineffective against challenge with strains unrelated by fluorescent antibody techniques. When the immune sera was incubated with the rickettsia in vitro and then inoculated into the mice a dramatic increase occurred in the number of surviving mice. The importance of these data in relation to published results with other species of rickettsia is discussed.