Hepatic damage and oxidative stress induced by Griseofulvin in mice.

Erythropoietic Protoporphyria (EPP) is a disease associated with ferrochelatase deficiency, which produces accumulation of protoporphyrin IX (PROTO IX) in erythrocytes, liver and skin. In some cases, a severe hepatic failure and cholestasis was observed. Griseofulvin (Gris) develops an experimental EPP with hepatic manifestations in animals. The aim of this work was to further characterize this model studying its effect on different metabolisms in mice Gris feeding (0-2.5%, 7 and 14 days). PROTO IX accumulation in liver, blood and feces, induction of ALA-S activity, and a low rate of Holo/Apo tryptophan pyrrolase activity was produced, indicating a reduction of free heme pool. The progressive liver injury was reflected by the aspect and the enlargement of liver and the induction of hepatic damage. Liver redox balance was altered due to porphyrin high concentrations; as a consequence, the antioxidant defense system was disrupted. Heme oxygenase was also induced, however, at higher concentrations of antifungal, the free heme pool would be so depleted that this enzyme would not be necessary. In conclusion, our model of Protoporphyria produced liver alterations similar to those found in EPP patients.

The time of tumor cell division and death depends on the site of growth.

We show here, for the first time, in two very different murine tumors, a mammary one (ectoderm) and a lung one (endoderm), that: tumors have day/night differences of spontaneous apoptosis additional to the well-known circadian rhythm of mitosis. The times of maximal and minimal mitosis and apoptosis changed for a tumor cell line when growing in different organs (as metastasis) or anatomical sites. Both tumor lines, have identical circadian curves when growing in a specific organ or anatomical site. The peaks of apoptosis match with the valleys of mitosis and vice versa.

Deferoxamine reduces tissue injury and lethality in LPS-treated mice.

We studied the effect of deferoxamine (DFX), an iron chelator, which can also act as a free radical scavenger, in an experimental murine model of sepsis. In vivo studies demonstrated that pretreatment of mice with DFX reduces tumor necrosis factor alpha (TNF-alpha) serum levels and increases the rate of survival of mice inoculated with lethal doses of lipopolysaccharide (LPS) or Escherichia coli O111:B4. By using the iron chelated form of DFX (ferrioxamine) the same results were obtained, suggesting that in this model, DFX could act as a free radical scavenger. On the other hand, DFX prevents mortality induced either by LPS or murine recombinant TNF-alpha in D(+)-galactosamine (GalN)-sensitized mice. These protective actions of DFX correlate with an attenuated tissue damage observed in lungs, livers and kidneys of LPS-treated animals and GalN-sensitized mice inoculated with TNF-alpha.

Two different types of concomitant resistance induced by murine tumors: morphological aspects and intrinsic mechanisms.

Concomitant resistance (CR) is the phenomenon according to which a tumor-bearing host inhibits the growth of a secondary implant of the same tumor at a distant site. Confirming and extending previous results of our laboratory, histological studies have revealed that two temporally separate peaks of CR can be detected throughout tumor evolution. The first peak induced by immunogenic small tumors, in euthymic but not in nude mice, is associated with extensive necrosis of the secondary tumor implant and a profuse infiltration of polymorphonuclear granulocytes and mononuclear cells resulting in its final destruction; these features correspond to a typical immunological rejection. The second peak of CR induced by both immunogenic and non-immunogenic large tumors, in euthymic as well as in nude mice, is characterized by a dormant tumor stage with scarce or null mononuclear infiltration, associated with a significant reduction of tumor mitotic index and of the number of PCNA+ cells along with an increase in apoptosis and an arrest in S phase. In previous reports we suggested that a 1000 D serum fraction from mice bearing large tumors could be responsible for the induction of this dormant tumor stage. In this study tumor cells incubated in vitro with that serum factor mimicked the inhibition and cellular alterations observed in vivo in the secondary tumor inhibited by the second peak of CR. Moreover, the passive transfer of this factor by the intra-peritoneal (i.p.) route induced an in vivo inhibition of an i.p. tumor reproducing the image characteristic of the second peak of CR. This represents a direct proof that this serum factor can restrain tumor growth in vivo and that it is, most probably, the effector of the second peak of CR.

Inhibition of metastases by a serum factor associated to concomitant resistance induced by unrelated murine tumors.

Murine lung metatases growing undisturbed by the primary tumor were significantly inhibited by the concomitant resistance induced by a secondary subcutaneous implant of two unrelated tumors. Such inhibition was T-independent since it was also observed in nude mice; its full expression was dependent on the presence of the secondary tumor implant and it was exerted on both macroscopic and microscopic established metastases and not on the process of tumor cell dissemination from the primary tumor. Direct and indirect mechanisms seemed to be involved, the former affecting the metastatic cells per se by causing a decrease in proliferation and an increase in apoptosis while the latter affected neo-vascularization. These antitumor and antiangiogenic effects could be attributed to a serum factor induced by the unrelated tumors generating concomitant resistance. This factor proved to be heat, acid and alkaline resistant and dialysable; it was recovered in an HPLC column with maximum absorption at 215 and 266 nm; it was anionic at neutral pH, exhibiting free carboxil groups and one or more molecules of tyrosine, with a molecular weight between 870 and 1300 Dalton. Intravenous administration of this factor significantly inhibited lung metastases, decreasing mitosis and increasing apoptosis similar to that observed in the presence of the unrelated tumors.

Adenomas of the colon: overexpression of p53 protein and risk factors.

BACKGROUND AND STUDY AIMS: p53 gene mutation and the ensuing overexpression of its protein is one of the steps related to colorectal carcinogenesis. This study analyzed the relationships between immunohistochemically detected p53 protein accumulation in colonic adenomas and morphological and clinical indicators of risk of malignant transformation and relapse. PATIENTS AND METHODS: A total of 100 endoscopically resected sporadic colonic adenomas (nonpolyposis) from 79 patients were retrospectively studied by using archival paraffin tissue blocks. p53 protein immunohistochemically detected was related to morphological adenoma risk factors (size, histological type and dysplasia) and in patients to neoplastic colonic pathology (NCP), such as previous adenomas/carcinomas or coexistent adenomas. RESULTS: There was a correlation between p53 expression and the grade of dysplasia but not with size or histological type in adenomas. NCP data was present in 52.5% of patients with p53 positive adenomas, and only in 25.6% of patients with p53 negative adenomas. This difference remains even in those with low-grade dysplastic lesions. When coexistent adenoma and previous adenoma/carcinoma data were analyzed separately, similar results were obtained. CONCLUSIONS: The presence of previous and/or coexistent NCP was more frequent in patients with p53 expressing adenomas, even in low-grade dysplastic lesions, which probably could be a high risk subpopulation. Its follow-up may be eventually reviewed.

Melanoma lentigo maligno:expresión de PCNA y EGFR / Lentigo maligna melanoma: expretion of PCNA and EGFR

Un total de 9 casos de Melanoma Léntigo Malignoi (MLM) fueron estudiados en relación a la expresión del antígeno nuclear de proliferación celular (PCNA) y el receptor del factor de crecimiento epidérmico (EGFR). Del total de casos se obtuvo marcación para la PCNA en el 88,8 por ciento (8/9) de los mismos siendo nula (0,9) para el EGFR. La frecuencia de marcación por caso para la PCNA fue similar a lo señalado para los otros tipos de melanoma. La tasa e ídice de positividad de la PCNA fue inferior a los restantes tipos histológicos en conjunto y al M.E.S. en particular, lo que podría indicar una tasa de proliferación menor en este subtipo histológico estudiado. Los resultados totalmente negativos para el EHFR, considerados válidos técnicamente, no permiten establecer, con certeza, conclusiones sobre su relación con este subtipo histológico de melanoma

Melanoma lentigo maligno:expresión de PCNA y EGFR / Lentigo maligna melanoma: expretion of PCNA and EGFR

Un total de 9 casos de Melanoma Léntigo Malignoi (MLM) fueron estudiados en relación a la expresión del antígeno nuclear de proliferación celular (PCNA) y el receptor del factor de crecimiento epidérmico (EGFR). Del total de casos se obtuvo marcación para la PCNA en el 88,8 por ciento (8/9) de los mismos siendo nula (0,9) para el EGFR. La frecuencia de marcación por caso para la PCNA fue similar a lo señalado para los otros tipos de melanoma. La tasa e ídice de positividad de la PCNA fue inferior a los restantes tipos histológicos en conjunto y al M.E.S. en particular, lo que podría indicar una tasa de proliferación menor en este subtipo histológico estudiado. Los resultados totalmente negativos para el EHFR, considerados válidos técnicamente, no permiten establecer, con certeza, conclusiones sobre su relación con este subtipo histológico de melanoma(AU)

Estudio de la clinica, patologia, estadios, evolucion del melenoma y marcadores pronosticos (PCNA y EGFR) / Study of the clinic, pathology, stadiamevolution from melanoma and prognosis makers

Se estudiaron 29 melanomas,en forma prospectiva en relacion a la exprecion del antigeno de proliferacion nuclear(PCNA)indicador de proliferacion celular y del receptor del factor de crecimiento epidermico(EGFR) responsable de estimular la hiperplasia.La PCNA mostro valores elevados y se correlaciono con los parametros habituales.El EGFR con bajo nivel de expresion,presento en el seguimiento un llamativo incremento en los niveles de invasion mas agresivos(nivel V)y en los casos del grupo de"fallecidos".

Estudio de la clinica, patologia, estadios, evolucion del melenoma y marcadores pronosticos (PCNA y EGFR) / Study of the clinic, pathology, stadiamevolution from melanoma and prognosis makers

Se estudiaron 29 melanomas,en forma prospectiva en relacion a la exprecion del antigeno de proliferacion nuclear(PCNA)indicador de proliferacion celular y del receptor del factor de crecimiento epidermico(EGFR) responsable de estimular la hiperplasia.La PCNA mostro valores elevados y se correlaciono con los parametros habituales.El EGFR con bajo nivel de expresion,presento en el seguimiento un llamativo incremento en los niveles de invasion mas agresivos(nivel V)y en los casos del grupo de"fallecidos".AU

Expression of gelatinase/type IV collagenase in tumor necrosis correlates with cell detachment and tumor invasion.

We have previously observed that acellular extracts from necrotic areas (NE) of the non-metastatic murine mammary adenocarcinoma M3, enhance in vitro cell detachment and spontaneous lung metastases. In the present study, using different proteinase inhibitors along with NE, only the calcium chelator EDTA could significantly abrogate the enhanced cell detachment from M3 produced by NE. The typical cleavage products of type IV collagenase were detected inside the tumor necrotic area, mainly in association with necrobiotic cells, as evaluated by Western blot analysis and immunohistochemical assays. Zymography revealed the presence of 72- and 92-kDa gelatinase/type IV collagenase in NE. Moreover, NE increased the in vitro invasive ability of cultured M3 cells. The use of specific antibodies against both 72- and 92-kDa type IV collagenases in the invasion assay showed that only the latter was able to revert the enhanced invasiveness to the baseline. It can be concluded that tumor necrosis is an important source of gelatinase/type IV collagenase, mainly in its 92 kDa form, and plays a major role in tumor invasion.

Anti-inflammation induced by counter-irritation or by treatment with non-steroidal agents inhibits the growth of a tumour of non-detected immunogenicity.

Counter-irritation (CI) triggered by different non-specific irritant stimuli delayed the growth of a murine tumour of non-detected immunogenicity. The syngeneic LB tumour transplant by itself also induced CI and decreased the number of leukocytes migrating to a secondary s.c. irritant stimulus, e.g. sponge or carrageenan. On the other hand, partial inhibition of cell migration by treatment with either 0.5 mg kg-1 indomethacin or 0.3 mg kg-1 piroxicam retarded LB tumour growth, presumably by a mechanism unrelated to inhibition of immune responses by PGE2. It is suggested that CI may play a role in the early stages of concomitant resistance.

Inmunidad concomitante antitumoral: un posible mecanismo de control de las metástasis / Antitumor concomitant immunity: a possible metastasis control mechanism

Se entiende por inunidad concomitante (IC) la falta de desarrollo de un segundo implante tumoral distante del primario, atribuyéndole una explicación inmunológica. El objeto de estos trabajos fue estudiar la IC asociada a tumores espontáneos. En ratones BALB/c, se comprobó que el transplante de varios tumores singenecicos, de indetectable inmunogenicidad, inhibían el desarrollo de un segundo implante del mismo tumor, y a veces de otro tumor, evidenciándose cierta inespecificidad. Esta IC se observada también en ratones atímicos, jóvenes y adultos, y en los tratados con sílica, descartándose la participación de linfocitos T, células NK y macrófagos. La falta de desarrollo del implante secundario no se debía a rechazo tumoral, contrariamente a lo que pudimos observar con un tumor inmunogénico en un sistema alogeneico, sino a citostasis. Este estado de tumor dormido se debería a la falta de aflujo de células del huésped, ya que cualquier estimulo inflamatorio local abrogaba la IC llevando a un rápido crecimiento tumoral. Estaría en juego un fenómeno de anti-inflamación ya que se comprobó que un foco inflamatorio inhibía el desarrollo de un implante tumoral en el flanco contralateral, que el mismo efecto se conseguía con la administración de piroxicam, y que el propio tumor disminuía la reacción inflamatoria creada por la implantación de un cuerpo extraño. Considerando a las metástasis como implantes secundarios naturales, se compararon dos tumores de mama de origen común, pero diferente...

Inmunidad concomitante antitumoral: un posible mecanismo de control de las metástasis / Antitumor concomitant immunity: a possible metastasis control mechanism

Se entiende por inunidad concomitante (IC) la falta de desarrollo de un segundo implante tumoral distante del primario, atribuyéndole una explicación inmunológica. El objeto de estos trabajos fue estudiar la IC asociada a tumores espontáneos. En ratones BALB/c, se comprobó que el transplante de varios tumores singenecicos, de indetectable inmunogenicidad, inhibían el desarrollo de un segundo implante del mismo tumor, y a veces de otro tumor, evidenciándose cierta inespecificidad. Esta IC se observada también en ratones atímicos, jóvenes y adultos, y en los tratados con sílica, descartándose la participación de linfocitos T, células NK y macrófagos. La falta de desarrollo del implante secundario no se debía a rechazo tumoral, contrariamente a lo que pudimos observar con un tumor inmunogénico en un sistema alogeneico, sino a citostasis. Este estado de tumor dormido se debería a la falta de aflujo de células del huésped, ya que cualquier estimulo inflamatorio local abrogaba la IC llevando a un rápido crecimiento tumoral. Estaría en juego un fenómeno de anti-inflamación ya que se comprobó que un foco inflamatorio inhibía el desarrollo de un implante tumoral en el flanco contralateral, que el mismo efecto se conseguía con la administración de piroxicam, y que el propio tumor disminuía la reacción inflamatoria creada por la implantación de un cuerpo extraño. Considerando a las metástasis como implantes secundarios naturales, se compararon dos tumores de mama de origen común, pero diferente... (AU)

Piroxicam treatment protects mice from lethal pulmonary challenge with Pseudomonas aeruginosa.

The effect of treatment with the nonsteroidal anti-inflammatory agent piroxicam on leukocyte migration to the lungs was investigated after aerosol administration of sublethal doses of Pseudomonas aeruginosa to mice. Piroxicam decreased, in a dose-related fashion, the polymorphonuclear leukocyte recruitment to, and the degree of perivascular and peribronchial infiltration in, the lungs. Piroxicam treatment also protected the animals in a dose-dependent manner from challenge with lethal doses of P. aeruginosa. The effect of piroxicam was not related to direct action of the drug on the microorganisms. Piroxicam treatment maintained the animal's pulmonary defenses against infection while diminishing inflammatory responses against P. aeruginosa, an occurrence decreasing the potential for tissue damage due to phagocytes migrating from circulation.

[Antitumor concomitant immunity: a possible metastasis control mechanism]. / "Inmunidad" concomitante antitumoral: un posible mecanismo de control de las metástasis.

Concomitant immunity (CI) is defined as the lack or retardation or proliferation of a secondary tumor implant at a distant site; it has been given an immunological interpretation. Our experiments were designed to investigate CI in association with spontaneous tumors with or without metastases. In BALB/c mice, various syngeneic tumors, of undetectable immunogenicity, induced CI, preventing the development of a secondary implant of the same and occasionally of another tumor, indicating some degree of nonspecificity. This CI could also be observed in young and adult nude mice with high and low NK level, and in those treated with silica, discarding and participation of T lymphocytes, NK cells and macrophages, respectively. The lack of development of the secondary implant was not due to tumor rejection--contrarily to observations in allogeneic systems with immunogenic tumor--but to cytostasis. This "dormant tumor" state is observed together with the absence of host cell infiltration. The creation of a local inflammatory reaction abrogated CI, resulting in rapid tumor growth. On the other hand, an inflammatory reaction created by a foreign body inhibited the development of a tumor implant in the contralateral flank and tumor growth could be inhibited by piroxicam; furthermore, the tumor itself diminished the inflammatory reaction created by a foreign body at a distant site. Considering metastases as natural secondary implants, two mammary adenocarcinomas with a common origin were compared, one with 0 and the other with 100% metastatic incidence. The non-metastatic tumor induced stronger and earlier CI against both tumors and prevented the development of experimental and spontaneous metastases; moreover; its surgical extirpation led to the appearance of lung metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

[quot ]Inmunidad[quot ] concomitante antitumoral: un posible mecanismo de control de las metástasis. / [Antitumor concomitant immunity: a possible metastasis control mechanism]

Concomitant immunity (CI) is defined as the lack or retardation or proliferation of a secondary tumor implant at a distant site; it has been given an immunological interpretation. Our experiments were designed to investigate CI in association with spontaneous tumors with or without metastases. In BALB/c mice, various syngeneic tumors, of undetectable immunogenicity, induced CI, preventing the development of a secondary implant of the same and occasionally of another tumor, indicating some degree of nonspecificity. This CI could also be observed in young and adult nude mice with high and low NK level, and in those treated with silica, discarding and participation of T lymphocytes, NK cells and macrophages, respectively. The lack of development of the secondary implant was not due to tumor rejection--contrarily to observations in allogeneic systems with immunogenic tumor--but to cytostasis. This [quot ]dormant tumor[quot ] state is observed together with the absence of host cell infiltration. The creation of a local inflammatory reaction abrogated CI, resulting in rapid tumor growth. On the other hand, an inflammatory reaction created by a foreign body inhibited the development of a tumor implant in the contralateral flank and tumor growth could be inhibited by piroxicam; furthermore, the tumor itself diminished the inflammatory reaction created by a foreign body at a distant site. Considering metastases as natural secondary implants, two mammary adenocarcinomas with a common origin were compared, one with 0 and the other with 100

metastatic incidence. The non-metastatic tumor induced stronger and earlier CI against both tumors and prevented the development of experimental and spontaneous metastases; moreover; its surgical extirpation led to the appearance of lung metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary synchronous bilateral breast cancer: epidemiological approach.

Twenty-eight (1.69%) cases of primary synchronous bilateral breast cancer (PSBC) out of 1,654 new cases were studied. PSBC compared with unilateral cases had a significantly higher (p less than 0.001) first degree family history of breast cancer; high frequency of subareolar location; no predominance of lobular and non-invasive types; no significantly different percentage of pathological stage I presentation. As there is no complete agreement on what constitutes a PSBC, studies should be carried out to formulate a more precise definition of this entity.

Tumor necrosis can facilitate the appearance of metastases.

The non-metastatic murine mammary adenocarcinoma M3 and its metastatic variant MM3 were used to evaluate the role of intratumoral necrosis in cell detachment and metastasis. Accelular extracts from necrotic areas of both tumors increased in vitro cellular detachment from M3 but not from MM3 fragments. Furthermore, the in vivo inoculation of the necrotic extracts within non-metastatic M3 tumors gave rise to pulmonary metastases. Histological studies revealed in M3 a central necrosis limited by an uninterrupted peripheral ring of well preserved cells, while in MM3 necrotic and non-necrotic areas alternated. It is concluded that the distribution of necrosis within the primary tumor by facilitating cell detachment is, at least in part, responsible for the development of metastases.

Role of concomitant resistance in the development of murine lung metastases.

An attempt was made to explain the distinct lung metastatic patterns of 2 mammary adenocarcinomas with a common BALB/c origin: M3, which does not induce spontaneous metastases, and MM3 with an almost 100% incidence. No difference between the 2 tumors was detected with respect to host mononuclear cell content, degree of immunogenicity or lung-colony-forming ability. Conversely, there was a marked difference in the capacity to induce concomitant resistance: M3-bearing mice induced stronger and earlier resistance against i.v. challenge of both M3 and MM3 tumor cells than MM3-bearing mice; this resistance was expressed as lower number of lung metastases and lower tumor-cell proliferation in metastatic nodules. M3 was also able to control the development of spontaneous metastases: metastases developed in all M3-excised mice, compared with none in M3-bearing mice, while MM3-bearing mice also bearing a secondary M3 tumor developed fewer metastases than mice bearing MM3 only. This anti-metastatic effect does not appear to depend on classical immunological mechanisms since no difference could be detected between the 2 tumors in response to T cells, NK, macrophages or antibodies.