In vitro cytotoxicity to various human tumor cell lines of a tumor cytotoxic factor(s) produced by human alveolar macrophages

When human alveolar macrophages (AM) obtained by lavage of the lungs of healthy donors were incubated in medium with or without lipopolysaccharide (LPS) they released a factor(s) with tumor cell killing activity. This tumor cytolytic and/or cytotoxic factor(s) (TCF) was assayed by measuring its effect in inhibiting target cell growth. TCF activity was not observed in the supernatant from cultures of LPS-treated hematopoietic malignant cell lines (monocytic leukemia, B-cell leukemia and T-cell leukemia cell lines). Human TCF was significantly cytotoxic to 13 of 15 solid-tumor cell lines tested and to 7 of 9 hematopoietic malignant cell lines, but not to two different normal, nontumorigenic cell lines. TCF-rich supernatants contained low levels of interferon (IFN) activity that were not significantly cytotoxic to A-375 melanoma cells. Human TCF and IFN-alpha or IFN-beta had additive cytotoxic effects. These data suggest that human TCF released by activated human AM may be of potential use in the treatment of malignant disseminated diseases.

Carcinoembryonic antigen (CEA) levels in pleural effusions and sera of lung cancer patients

For determining the value of carcinoembryonic antigen (CEA) levels in diagnosis of malignant tumors of the lung, the CEA levels in 187 specimens of pleural fluid and sera obtained simultaneously from patients with pleural fluid were measured. In all 70 patients with benign diseases, the CEA levels in the effusions were less than the cut-off value of 5 ng/ml (mean +/- SD: 1.44 +/- 1.01 ng/ml). In contrast, in 88 of 117 patients (75.2%) with malignant diseases, the CEA levels in the effusions were over 5 ng/ml (25.3 +/- 24.5 ng/ml) and in 58 of the 117 patients (50.4%), the CEA levels in the serum were values of 5 ng/ml or more (11.9 +/- 18.4 ng/ml). There was a significant correlation between the CEA levels in the effusions and in the sera. The CEA levels in effusions in patients with malignant lung tumors were usually much higher than those in their sera. The incidence of CEA levels of 5 ng/ml or more in both the serum and effusion was highest in the patients with adenocarcinoma. These data indicate that determination of the CEA level in effusions, when done in combination with cytological examinations, may have additional value in diagnosis of lung cancer.

Sonographically guided needle biopsy for diagnosis of thoracic lesions

Fluoroscopically guided percutaneous biopsy of thoracic lesions is widely accepted. However, some lesions are not sufficiently visible on fluoroscopy. When this is the case, sonographic guidance may be helpful. Real-time sonographically guided needle biopsy was performed in 38 such cases, including 27 pulmonary nodules adjacent to the chest wall, three mediastial tumors, five chest wall masses, and three pleural lesions. Definitive diagnoses were made in 30 cases (78.9%), including 21 (91.3%) of 23 malignancies and nine (60%) of 15 benign lesions. Sonographically guided needle biopsy could be performed safely and easily, taking advantage of the real-time monitoring of needle position for the pulmonary masses located adjacent to the chest wall, even when fluoroscopic or CT guidance was not effective. It is suitable for biopsying chest wall tumors, pleural lesions, and anterior mediastinal masses. It is particularly suited to biopsying small pulmonary nodules adjacent to the chest wall, nodules in the apical or juxtadiaphragmatic regions, and those obscured by pleural effusion.

Establishment of human KB cells resistant to 1-beta-D-arabinofuranosylcytosine, and mechanisms of cellular resistance in isolated clones

A subline of human KB cells that was resistant to 1-beta-D-arabinofuranosylcytosine (ara-C) was established by continuous exposure of the cells to increasing concentrations of ara-C. Thirteen resistant clones were isolated from the resistant subline (KB/ara-C). KB/ara-C showed 1,300-fold higher resistance than the parent KB cells to ara-C; the most resistant clones, clones 7 and 10, showed 1,330-fold higher resistance. In the absence of ara-C, the resistance of the parent KB/ara-C cells was stable for at least 14 weeks, whereas that of clone 7 was stable for 10 weeks, but was slightly less after 14 weeks. The ara-C kinase and ara-C deaminase activities of the 13 clones and the cellular uptake of ara-C by several clones were measured. In general the clones showed decreased deoxycytidine kinase activity and decreased cellular uptake of ara-C. Most clones had higher cytidine deaminase activity than KB cells, but some had activity similar to that of the KB cells. A clear inverse relationship was found between the ara-C sensitivity of the clones and their kinase activity, but not their deaminase activity or their ara-C uptake. These results clearly demonstrate that a major mechanism of ara-C resistance of these human KB cells was a decrease in the activity of the ara-C activating enzyme deoxycytidine kinase. The parent KB/ara-C cells showed no clear cross-resistance to various antitumor agents other than an ara-C derivative, including metabolic inhibitors, alkylating agents, DNA binders and mitotic spindle poisons.

Potentiating effect of muramyl dipeptide and its lipophilic analog encapsulated in liposomes on tumor cell killing by human monocytes

Human monocytes harvested from healthy donors and separated by discontinuous gradient centrifugation and adherence were highly cytotoxic to allogeneic melanoma cells, but did not affect nontumorigenic cells, as measured by lysis of the cells. After 4 days incubation of these monocytes in medium, they showed little, if any, cytolytic activity. Hydrophilic muramyl dipeptide (MDP) or lipophilic muramyl tripeptide (MTP-PE) was encapsulated within multilamellar (MLV) liposomes composed of phosphatidylserine-phosphatidylcholine. The cultured monocytes were rendered tumoricidal by interaction for 24 hr with MDP or liposomes containing soluble MDP or lipophilic MTP-PE. Moreover, freshly isolated monocytes treated for 24 hr with liposomes containing MDP or MTP-PE remained tumoricidal during culture for up to 5 days. About 1,600-times lower concentration of MDP entrapped in liposomes than of free MDP in the medium was effective for rendering monocytes tumoricidal. Similarly, about 80-times lower concentration of MTP-PE in liposomes than of free MDP was effective for the activation of monocytes. It is concluded that MLV liposomes containing MDP or MTP-PE are far more efficient in potentiating the tumoricidal activity of human monocytes than unencapsulated, free MDP.

Potentiating effect of muramyl dipeptide and its lipophilic analog encapsulated in liposomes on tumor cell killing by human monocytes

Human monocytes harvested from healthy donors and separated by discontinuous gradient centrifugation and adherence were highly cytotoxic to allogeneic melanoma cells, but did not affect nontumorigenic cells, as measured by lysis of the cells. After 4 days incubation of these monocytes in medium, they showed little, if any, cytolytic activity. Hydrophilic muramyl dipeptide (MDP) or lipophilic muramyl tripeptide (MTP-PE) was encapsulated within multilamellar (MLV) liposomes composed of phosphatidylserine-phosphatidylcholine. The cultured monocytes were rendered tumoricidal by interaction for 24 hr with MDP or liposomes containing soluble MDP or lipophilic MTP-PE. Moreover, freshly isolated monocytes treated for 24 hr with liposomes containing MDP or MTP-PE remained tumoricidal during culture for up to 5 days. About 1,600-times lower concentration of MDP entrapped in liposomes than of free MDP in the medium was effective for rendering monocytes tumoricidal. Similarly, about 80-times lower concentration of MTP-PE in liposomes than of free MDP was effective for the activation of monocytes. It is concluded that MLV liposomes containing MDP or MTP-PE are far more efficient in potentiating the tumoricidal activity of human monocytes than unencapsulated, free MDP.

Stimulatory effect of vitamin A on tumoricidal activity of rat alveolar macrophages

F344 rats were given saline, vitamin A placebo or vitamin A analogues orally for 4 consecutive days. The following day they were killed and their alveolar macrophages (AM phi) were harvested by lavage. The functional integrity of the AM phi was determined by their capacity to phagocytize opsonized SRBC and to kill syngeneic adenocarcinoma cell lines nonspecifically. Results showed that 4 days treatment with greater than 100 IU of vitamin A as retinyl palmitate per gram body weight rendered the AM phi tumoricidal against syngeneic mammary adenocarcinoma cell lines (MADB-100 and MADB-200) and that AM phi activated with retinyl palmitate showed increased ability to phagocytize opsonized SRBC. Other retinoids, such as retinoic acid and retinol, had the same effect of inducing tumoricidal activity in rat AM phi. AM phi harvested from normal rats were also rendered tumoricidal by direct interaction with greater than 10(3) IU ml-1 of retinyl palmitate for 24 h in vitro. Thus, vitamin A at high doses can increase the phagocytic and tumoricidal activities of rat AM phi.

Production of a tumor cytolytic factor(s) by activated human alveolar macrophages and its action

When human alveolar macrophages (AM) lavaged from healthy donors were incubated in medium with or without lipopolysaccharide (LPS) or muramyl dipeptide, they released a factor(s) responsible for tumor cell killing. The activity of the tumor cytolytic factor(s), called TCF, was determined by radioactive release assay. Human AM released variable amounts of TCF into the culture medium without any stimulation, but the release was stimulated significantly by LPS (0.1 micrograms/ml) or muramyl dipeptide (1 micrograms/ml). Maximal production of TCF by the AM was detected in the supernatant after treatment for 3 hr with LPS, and the extent of TCF release correlated with the density of AM. In cultures with LPS, the ability of activated AM to secrete TCF was maintained for 48 hr but was lost by 96 hr. After its loss, the ability to produce TCF could be restored by a second treatment with LPS. Full expression of lysis by TCF to lyse tumor cells required its interaction with tumor cells for at least 24 hr. TCF destroyed human allogeneic tumor cell lines but did not affect nonneoplastic cell lines. TCF activity was resistant to treatment with protease inhibitors, superoxide dismutase, or catalase and to heating at 70 degrees for 1 hr, but it was labile on heating at 100 degrees for 10 min. The tumoricidal activity in the supernatant of activated human AM indicates a potential effector mechanism by which AM kill neoplastic cells.

Activation by a new synthetic acyltripeptide and its analogs entrapped in liposomes of rat alveolar macrophages to the tumor cytotoxic state

FK-565 (heptanoyl-gamma-D-Glu-(L-meso-a, epsilon-A2pm (L)-D-AlaOH) is a synthetic acyltripeptide closely resembling cell wall peptidoglycan peptides of Streptomyces in structure. Alveolar macrophages (AM) lavaged from lungs of F344 rats were activated by in vitro treatment with FK-565 and its derivatives at concentrations of 1-50 micrograms/ml medium, and the activated AM killed syngeneic mammary adenocarcinoma cells. When FK-565 and related compounds were encapsulated in multilamellar (MLV) liposomes composed of phosphatidylcholine and phosphatidylserine, dose-response experiments showed that they were about 800 times more effective than the free compounds in activating AM. Liposome-encapsulated FK-565 and its analogs caused significant activation of AM within 4 h. These data indicated that acyltripeptide and its analogs encapsulated in liposomes are more efficient than the free compounds in rendering AM tumoricidal.

Ultrastructural changes of alveolar macrophages of protein-deficient rats

Enhancement of phagocytosis of alveolar macrophages (AM) was examined by cytochemical and electron microscopic studies on macrophages from protein-deficient rats. The macrophages from rats fed on 5% casein diet had longer microvilli, more phagocytic vacuoles and more lysosomes with acid phosphatase activity than those from control rats. Many phagocytic vacuoles were seen close to the site of attachment of opsonized sheep red blood cells (SRBC) and were mainly located in the subplasmalemmal layer which was rich in microfilaments but contained few cytoplasmic organelles. After attachment, opsonized SRBC were engulfed through a hemispherical crater into the phagocytic vacuoles. The phagocytic vacuoles seemed to be formed by invagination of the cell surface because they had membrane ATPase activity continuous with that of the outer surface of the plasma membrane. In the cell, the vacuoles fused with the numerous preexisting lysosomes in the interior of the cell receiving the contents of the latter. The mechanism of enhancement of phagocytosis in protein-deficiency is discussed.

CT anatomy of hilar lymphadenopathy

The normal distribution of lymph nodes in the pulmonary hili is diagrammatically shown, with a typical computed tomographic (CT) demonstration of hilar lymphadenopathy. On the basis of observations in anatomic cross sections of cadaver lungs, the lymph nodes in the right lung can be divided into four principal groups (right upper lobe, interlobar, middle lobe, and lower lobe) and in the left lung into three principal groups (left upper lobe, interlobar, and lower lobe). Most of the hilar lymph nodes are situated along the bronchi in close relation with the pulmonary vascular branches. Because of this close proximity, contrast-enhanced CT images are indispensable for precise CT interpretation of a hilar lymphadenopathy.

Changes of alveolar macrophages in protein-deficient rats

Protein malnutrition was achieved by feeding female F344 rats a 5% casein diet for 7 weeks. At appropriate times, animals were killed and their alveolar macrophages (AM) were obtained by broncho-pulmonary lavage of the lung. Functional changes of AM were determined by measuring phagocytosis of latex beads, yeast cells or opsonized sheep red blood cells (SRBC) and the ability to respond to a macrophage-activating factor (MAF) such as lymphokines. After 3 weeks on a low casein diet, the number of AM was much lower than in rats on control diet, but the abilities of the AM to phagocytose latex and yeast cells were the same as those of controls. Phagocytosis of opsonized SRBC was higher than in control rats but could not be enhanced by in vitro treatment with MAF. The most striking ultrastructural feature of these AM was the abundance of finger-like microvilli on the cell surface before phagocytosis; after ingestion of SRBC into phagocytic vacuoles there were only a few short microvilli on the surface. These data suggest that dietary protein malnutrition affects the number and phagocytic functions of AM responsible for host defense in the lung.