GM-CSF secreted by murine adenocarcinoma cells modulates tumor progression and immune activity.

During tumor development, growth factors may act in autocrine manner stimulating cell proliferation, or in paracrine manner affecting the microenvironment of the tumor and modulating the immune system. Murine mammary adenocarcinoma M3 tumor bearers develop lung metastases and leukocytosis during its evolution. Previously we described that M3 conditioned media enhanced metastasis incidence, when it was inoculated in tumor-operated mice. In the present study we determine that spleen cells from M3 tumor operated mice treated with M3 conditioned media, were able to transfer the capacity to enhance metastasis to other tumor operated mice. Spleen cells have immune suppressor activity that could be reversed by cyclophosfamide treatment. M3 tumor cells secrete GM-CSF, which is able to promote in vitro proliferation of M3 cells as well as spleen cells. This proliferation could be abrogated by the addition of anti-GM-CSF. We report that the GM-CSF secreted by M3 tumor cells had stimulatory activity on M3 tumor cell and lymphocyte proliferation.

Immune reactivity during the growth of a murine lung adenocarcinoma: evaluation of paraneoplastic syndrome development.

The purpose of this study was to investigate if specific immune responses were present in mice bearing a lung adenocarcinoma that presents paraneoplastic syndromes during tumor evolution. Leukocytosis, mainly due to polymorphonuclear leukocytes, was found from day 15 of tumor growth. Delayed type hypersensitivity response and increased interleukin-6 (IL-6) serum levels were observed along tumor growth. Concomitant immunity, specific rejection of a second inoculum and in vitro specific cytotoxicity occurred at 20 days of implant. In advanced stages of tumor evolution impaired cytotoxicity, accompanied by a great increase of IL-6 in serum, were observed. Role of polymorphonuclear leukocytes and IL-6 overproduction as responsible for immune dysregulation and paraneoplastic syndromes are discussed.

Expression of CD44 splice variants in spontaneous murine tumors.

CD44 is a widely distributed set of cell surface glycoproteins expressed in several types of cells and tissues, implicated in cell-cell and cell-substrate interactions. This molecule plays a major role in cell differentiation, development and activation and has also been described as a potential marker of malignancy and metastasis. In the present study we investigated by RT-PCR followed by exon specific amplification the expression of CD44 splice variants in four different murine tumors as well as in the invaded organs in order to correlate the expression of CD44 variants with potential tumor invasiveness and their implications for growth. Our data showed deregulation in the expression of CD44 isoforms but no discernible correlation in isoform expression pattern. However, in all tumors studied isoforms presented by the primary tumor were detected in the invaded organs before metastasis could be demonstrated by histopathological analysis.

New murine cell line derived from a spontaneous lung tumor induces paraneoplastic syndromes.

LP07 is a new cell line derived from P07 lung tumor, spontaneously arisen in a BALB/c mouse. LP07 is composed of heterogeneous epithelioid polyhedric cells that proliferate at a slow rate, have low plating efficiency and are unable to grow in soft agar. Only some LP07 cells expressed cytokeratins while most of them were positive for vimentin. Ultrastructure studies showed that LP07 cells established rudimentary intercellular unions, formed glandular-like conducts and presented conspicuous secretory granules, suggesting an epithelial-glandular origin, with neuroendocrine components. Upon injection LP07 cells formed poorly differentiated non-invasive adenocarcinomas, and tumor bearing mice developed leukocytosis, hypercalcemia and cachexia. This tumor cell line constitutes a useful tool to study lung tumor biology and paraneoplastic syndromes.

Mechanisms of paraneoplastic syndromes in mice bearing a spontaneous lung adenocarcinoma.

Paraneoplastic syndromes are rarely described in animal models. It may be useful to have a suitable experimental model to study the mechanisms by which they are produced. In this study, we describe a murine lung adenocarcinoma, P07, which presents hypercalcemia, leukocytosis and cachexia. We determined the presence of PTHrP in plasma as well as GM-CSF produced by P07 cells. TNF-alpha, which is responsible for cachexia, could neither be detected in serum nor in P07 cell supernatants. We conclude that this model, which shows paraneoplastic syndromes similar to those of lung tumor patients, should be useful to study the pathways and significance of these signs.

A synthetic, nitrogenated antimetastatic and anti-angiogenic compound with low toxicity in vivo.

The design of more effective therapies for metastatic disease involves development of new compounds able to specifically block the malignant process. We demonstrated previously that a new synthetic nitrogenated compound 3'-1-chloroethyl-2,3-dihydro-1H-imidazo-(2, 1-i)-purine-4-ium-7-yl-3'-deoxy-1',5', 6'-tri-O-(methylsulfonyl)-muco-inositol chloride (DIC) had an anti-proliferative activity on tumor cells in vitro. In the present work we demonstrate that DIC induces apoptosis on the LM3 murine mammary adenocarcinoma cell line in vitro and has anti-angiogenic activity in vivo. We also evaluated toxicity, biodistribution and anti-neoplastic properties of DIC in vivo. Toxicity studies allowed us to establish the LD50 (750 mg/kg body weight). Administration of 250 mg/kg/day (LD10) for 6 days did not cause overt toxic effects. Biodistribution assays revealed that DIC was rapidly eliminated (60% at t=10 min), although it accumulated in tumor tissue at higher concentrations than in other tissues. Daily s.c. treatment with DIC (LD10) for 24 days significantly reduced the number of spontaneous lung metastases. These results suggest that DIC has the ability of impairing the metastatic development by inhibiting angiogenesis and inducing apoptosis on tumor cells.

Spontaneous murine lung adenocarcinoma (P07): A new experimental model to study paraneoplastic syndromes of lung cancer.

We report the histological and biological behavior characteristics of a lung tumor (P07) that arose spontaneously in a Balb/c mouse. P07 is a moderately to poorly differentiated adenocarcinoma that secretes granulocyte-macrophage colony stimulating factor (GM-CSF) in culture supernatants. This tumor presents some paraneoplastic syndromes, such as leukocytosis, hypercalcemia and cachexia. taken together with the peripheral blood leukocyte (PBL) counts and serum calcium levels during s.c. tumor growth and after surgery, this study suggests that P07 may be a useful experimental model to study the biology of lung cancer and paraneoplastic syndromes.

Effects of in vivo culture of murine mammary adenocarcinoma cells on tumor and metastatic growth.

We studied the effect of tumoral microenvironments on metastatic phenotypes. Therefore, murine mammary adenocarcinoma cells cultured in vivo in diffusion chambers (DC) were implanted intraperitoneally in BALB/c mice. The behavior of DC-cultured cells was compared with that of cells obtained from tumors growing subcutaneously or intraperitoneally and from primary cultures in vitro of the former. DC-cultured and control cells were inoculated into normal mice to evaluate their tumorigenicity and metastasizing ability. We found that DC-cultured cells were less tumorigenic and metastatic both in spontaneous and in experimental metastasis assays. The host response to tumor progression resulted in an early leukocytosis, probably due to the overproduction of a hematopoietic factor by the tumor cells. Finally, it was found that DC-cultured cells produced lower levels of urokinase-type plasminogen activator activity, while no differences were found in the metalloproteinase production compared to cells obtained from a tumor growing subcutaneously.

Involvement of nitric oxide in the regulation of peripheral blood leukocyte counts.

A role for nitric oxide (NO) in the regulation of blood leukocyte numbers was examined in BALB/c mice by employing the NO synthase inhibitor NG-nitro L-arginine methyl ester (L-NAME). Treatment of animals with a single dose of 50 mg/kg body wt caused a dramatic increase in the number of circulating neutrophils and a moderate decrease in the number of circulating lymphocytes. These effects were partially reversed by the simultaneous inoculation of L-arginine (250 mg/kg body wt.) but not by D-arginine. A second NO synthase inhibitor, NG-nitro L-arginine, induced changes comparable to those elicited by L-NAME. Because catecholamines and glucocorticoids are well-known modulators of blood leukocyte counts, experiments were carried out in adrenalectomized mice. It was found that adrenalectomy did not modify the increase in the number of circulating neutrophils induced by L-NAME but completely prevented the decrease of circulating lymphocytes. Taken together, these findings support the hypothesis that NO plays an important role in the regulation of the peripheral blood number of neutrophils and lymphocytes, and that this function involves, in each case, the participation of different mechanisms.

A comparison of imaging techniques in patients with chronic sinusitis (X-ray, MRI, A-mode ultrasound).

Thirty-five patients age 9 to 67 were evaluated for chronic sinusitis by history, physical and laboratory examination, and imaging techniques (X-ray, magnetic resonance imaging (MRI) and flexible rhinoscopy). MRI was the most predictive. To establish the diagnosis of sinusitis, it was more sensitive than plain X-ray for intrasinus disease. Findings of edema, erythema, and drainage on flexible rhinoscopy were consistent with chronic sinusitis and were confirmed by MRI and sinus X-rays in 41% of the cases. Nasal smears for polymorphonuclear cells and eosinophils were suggestive of a diagnosis of chronic sinusitis, but other laboratory tests (CBC, sedimentation rate, quantitative immunoglobulins, total IgEs) were of very limited value in the diagnosis of chronic sinusitis.

Tumor cells cultured in vivo in diffusion chambers induce hematological alterations.

We have studied in BALB/c mice the hematological alterations of the host induced by the growth of tumor cells in diffusion chambers (DC) In this model, host-tumor interactions are only mediated by soluble factors. Tumor cells proliferate and grow in DC up to 15 days after implant. Our results show a reversal of the granulocyte-lymphocyte ratio in peripheral blood, with lymphopenia and a relative increase of myeloid progenitors in the bone marrow of mice bearing DC with M3 tumor cells (M3TC).

Immunomodulation by soluble factors from tumor cells cultured in vivo in diffusion chambers.

The delayed-type hypersensitivity (DTH) response and lymphocyte-mediated angiogenesis were determined in mice bearing in vivo cultures of mammary tumor cells in diffusion chambers (DCs). Soluble tumor products which diffuse from the DCs were able to stimulate the immune system for both the DTH reaction and angiogenic activity by spleen cells.

Prevalence and longitudinal study of breast masses in adolescents.

This study examined the prevalence and outcome of breast masses in adolescent females and compared these teens to those without breast masses. A longitudinal study of adolescents with breast masses was conducted from October 1984 through January 1990. The prevalence of discrete breast masses in the 13-month study period was 13/400 (3.25%) among new female patients. The mean length and width of the masses were 2.8 and 1.9 cm; 86% had a solitary mass. Of 61 diagnosed with breast masses, 39 were followed for up to 40 months (mean, 7 months). Teens with a mass were older (16.8 versus 15.1 years, p < 0.001) and had a greater chance of a family history of breast disease (26% versus 10.5%, p < 0.05) than those without a breast mass. Of 39 teens returning for at least one follow-up visit, 10 had a clinical diagnosis of "fibrocystic changes." Of these, the lesions resolved in six. Of the 29 teens with a discrete mass on examination, 7 underwent surgery and were found to have fibroadenomas. Nine of the 29 teens had masses which resolved over 1-12 months, six teens had masses which remained unchanged over 3-40 months, while four had masses which became smaller, and two had masses which became larger. One teen with mastitis improved. Eighteen underwent ultrasonographic examination at the breast. Of the 12 teens found to have a solid mass on ultrasound, none had a mass that resolved on follow-up examination.(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnosis of sinusitis in infants and children: x-ray, computed tomography, and magnetic resonance imaging. Diagnostic imaging of pediatric sinusitis.

Plain film radiographic examination, the historical standard, is rapidly being supplanted by computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of sinusitis. In particular, many endoscopic surgeons consider CT to be a mandatory part of the preoperative evaluation. MRI is useful for cases complicated by orbital or intracranial extension. However, because of considerations of cost, the need for sedation, and for CT radiation exposure, conventional x-ray films will continue to play an important role in the diagnosis and management of medically treated sinus disease. Incidental sinus abnormalities in children without apparent symptoms are usually the result of resolving, uncomplicated upper respiratory tract infection. Opacification, moderate-to-severe mucosal thickening, or air fluid levels in patients with persistent symptoms indicate sinusitis. Sinus imaging in children, whatever the modality, is demanding both in obtaining technically adequate studies and interpreting findings. Poor-quality examinations usually overestimate the presence and severity of disease. Ideally, children should be referred to centers with expertise in pediatric ear, nose, and throat imaging.

Double-lumen central venous catheter for percutaneous ureteral perfusion studies.

A commercially available double-lumen central venous catheter that can be inserted over a 0.018-inch guide wire was used for ureteral perfusion studies in three infants. Complications or difficulties were not encountered in any patients. This technique allows simultaneous monitoring of perfusion and intrarenal pressure and requires only a single puncture of the renal pelvis with a 21-gauge needle.

[Immunoregulation of tumor growth in a murine model]. / Inmunorregulación del crecimiento tumoral en un sistema murino.

Different spleen and tumor cell factors modifying tumoral and metastatic growth were studied. Spleen cell culture supernatants (SCS) from small and large tumor-bearing mice enhanced tumor growth. After tumor surgery, tumor enhancement was only mediated by supernatants from large tumor resected mice. Tumor facilitation and angiogenic response were mediated by the same supernatants; different fractions for these two activities were characterized. T and non-T cells, depending on tumor burden, were responsible for the enhancing activity; but angiogenesis depended only on T cells. While augmentation of metastatic spread was produced by tumor antigens (soluble tumor extracts, tumor-cell supernatants, formolized tumor cells), primary tumor development was not modified by tumor-cell supernatants. Increased incidence of metastases was also mediated by SCS from tumor resected mice which had previously been inoculated with tumor antigens. Immune status of tumor-resected mice was evaluated by delayed-type hypersensitivity reaction. Tumor cell membranes enriched with cholesterol-hemisuccinate were able to increase anti-tumor immune response.