Kupffer cells recognize trinitrobenzene-labeled erythrocytes.

Chemical-modified erythrocytes (trinitrobenzene-modified erythrocytes (TNB-RBC)) are trapped in vivo rapidly by liver macrophages (Kupffer cells). The liver homing of TNB-RBC is dependent on the concentration of TNB-residues coupled to the surface of RBC. High concentrations induce liver homing, low concentrations spleen homing.

Invasive activities of metastasizing and nonmetastasizing tumor cell variants in vitro. II. Studies on confrontations with aorta, vein, ductus thoracicus, diaphragm, and lung.

In continuation of a previous paper (1), we have prolonged the time of confrontation of two rat tumor cell variants (BSp73 AS and ASML) with normal epithelial cells and broadened the spectrum of confrontation partners. In addition to the aorta we have also used small veins, the ductus thoracicus as a lymphatic vessel, the diaphragm, and lung fragments. The organ sections were preserved for a longer period of time by incubating them in a gyratory shaker. Under these conditions the vessel material and diaphragm remained morphologically intact for up to 12 hrs; lung cubes concealed the cut surfaces by immediate wound healing, and were preserved intact for up to 40 days. All endothelia and the mesothelium of the diaphragm were destroyed by the nonmetastasizing AS cells, but the basal lamina remained intact by morphological criteria even after 18 hrs of exposure to the AS cells. The metastasizing ASML cells attached by filopodia mostly to the basal lamina of the vessels, but were unable to destroy neither the endothelia nor the basal lamina. The superficial cell layers of the lung cubes, however, were penetrated by the cells of both tumor lines, but to a different degree.

Inhibition of antibody synthesis and expression of T-cell membrane markers by serum factors of patients with small cell carcinoma of the lung.

Serum of patients with small cell lung cancer as well as serum fractions recovered by column chromatography inhibit the in vitro antibody synthesis in a PWM driven lymphocyte culture system and the capacity of T-lymphocytes to form rosettes with sheep erythrocytes. Utilizing an in vitro antibody synthesis system recomposed of previously separated B-cells and T-helper cells, we could show that the inhibiting high-molecular weight factors (between 40,000 to 60,000 dalton) from the patients' serum are suppressing antibody synthesis by inactivation of T-helper cell function. The mechanisms of inhibition are still unclear. The factors inhibiting E-rosette formation which are in the molecular weight range of 10,000 dalton and lower are not the same as the factors suppressing the antibody production.

Invasive activities of metastasizing and nonmetastasizing tumor cell variants in vitro.

Pieces of the endothelium of the aorta of BDX rats were confronted with two syngeneic-tumor-cell variants. While the AS variant is non-metastasizing, the ASML cells metastasize spontaneously via the lymphatic vessels. By means of scanning-electron microscopy the adhesion phenomena and the various stages of invasive activity of the non-metastasizing variant (AS) as well as the retraction of the endothelial cells depending on the time of confrontation were studied. Though the metastasizing variant (ASML) adhered firmly to the endothelium, we found neither signs of invasive activity of these tumor cells nor retraction phenomena of the endothelial cells. Aggregates of AS- and clusters of ASML-cells, respectively, behaved in exactly the same way as single cells: while the ASML-clusters remained inactive, the AS-aggregates exhibited invasive activities. Those cells which were in intimate contact with the endothelium started to leave the aggregate, thereby forming a foot-like layer beneath the rest of the aggregate; these cells began to invade.

Ultrastructural analysis of experimentally induced invasion in the rat lung by tumor cells metastasizing lymphatically.

The colonization of the lung by the rat tumor cells BSp73 ASML which have the ability to metastasize via the lymphatic system was studied at the ultrastructural level. Tumor cells arriving in the lung after i.v. injection become transiently embolized; within hours, however, they begin to extravasate from the blood capillaries. Swelling cellular protrusions open a limited area between endothelium and basal lamina through which tumor cells erupt. Tumor cells then form metastases in the interstitial tissue and, in an apparently lymphotropic action, intravasate the lymphatic vessels in a similar manner to a reverse diapedesis-like process. Within the lympatic system they settle, spread, and build up extensive tumor foci particularly in the subpleural region.

Adhesion and spreading characterization of a rat tumor cell system exhibiting different metastatic behavior.

The rat tumor cell system BSp73AS/BSp73ASML was investigated for its structural aspects. The non-metastasizing line BSp73AS has less nuclear atypism than the metastasizing line BSp73ASML. Microvilli are scanty and variable in length and structure; in BSp73ASML they cover the cells densely, are short and homogeneous in size. In vitro adhesion and spreading tests show structurally flexible BSp73AS cells which flatten completely onto substrata. BSp73ASML cells remain spherical and develop only small attachment areas. In vitro aggregation of the BSp73AS cells leads to round, tightly packed aggregates, their outer cell layer is epitheloid BSp73ASML cells form clusters of mostly ball-shaped cells. Surprisingly, as judged from EM images, the intercellular junctions in BSp73ASML cell clusters are qualitatively the same as in BSp73AS cell aggregates. However, the extent of apposition between cells in BSp73AS aggregates is much higher than between cells in the BSp73ASML clusters. BSp73ASML cells lack the ability to vary their shape. This is the prominent difference revealed by these tests between the two cell lines. Hence, this fact could play an important role in their different metastatic behavior in vivo. We speculate that the ability to vary the cell shape is necessary for expansive growth in the host environment but not for the metastatic spread.

Studies on intravascular phagocytosis in the lung.

In this paper we have shown for the first time endocytosis by intravascular lung phagocytes. Glutaraldehyde-treated erythrocytes (discocytes) homed rapidly to the rat lung as measured by scintigraphic procedures. Transmission and scanning electron microscopy showed that the discocytes are phagocytosed by macrophages, blood monocytes and granulocytes as whole cells. This process could not be inhibited by silica treatment.

[Immune status of patients with bronchial cancer]. / Der Immunstatus von Patienten mit Bronchialkarzinom.

The proliferation of lymphocytes, the cell-surface markers of mononuclear cells, and the capacity of T lymphocytes to bind sheep red blood cells were studied in 61 healthy volunteers and 72 patients with small-cell carcinoma, adenocarcinoma, and squamous-cell carcinoma of the lung. The mitogen-stimulated proliferation of the lymphocytes against phytohemagglutinin (PHA) was significantly reduced in patients with small-cell carcinoma. The number of T lymphocytes with T3, T4, T8, and T11 receptors was also reduced, to a degree similar to the E-rosetting rates of patients with small-cell carcinoma. The behavior of the lymphocytes of patients with either adeno- or squamous-cell carcinoma was similar to the normal persons. With regard to prognosis, we could not find significant differences between patients with "limited" and those with "extensive disease".

Morphological and behavioral characteristics of two rat tumor cell lines with different metastatic capacities.

The morphological characteristics of two rat tumor cell lines were studied by means of scanning electron microscopy. While the ASML-cells (Ascites, Solid, Metastases, Lung) when spread via the lymphatic vessels form metastases in the lung, the AS-cells (Ascites, Solid) do not form secondary tumors. The ASML-cells do not attach on glass or plastic but grow in suspension; AS-cells, can be cultivated as monolayers. The ASML-cells form loosely packed clusters when they are shaken in a gyratory shaker, AS-cells produce well organized aggregates in which the intercellular contacts are very intensive. When a mixture of cells from both lines is aggregated the two types sort out and the line-specific aggregate or cluster is formed without interaction between the two types. ASML-cells remain spherical when confronted with pieces of the aortic wall and there are no signs of reaction with the underlying endothelial cells. The endothelium is drastically altered when AS-cells are seeded on top of the aortic wall: the tumor cells flatten, penetrate the endothelial layer and induce the endothelial cells to retract. These phenomena can also be seen in confrontations with the mesothelium of the diaphragm. As also cells from aggregates or clusters behave as the single cells we conclude that the newly formed heterotypic contacts are favored over homotypic ones. In addition they have proved to be more intensive.

A phase I study of lobaplatin (D-19466) administered by 72 h continuous infusion.

A phase I trial with continuous intravenous infusion of lobaplatin (D-19466; 1,2-diamminomethyl-cyclobutane-platinum (II)-lactate) for 72 h was performed to determine the maximum tolerated dose (MTD). Each patient received a single dose level, the total dose of lobaplatin ranged from 30 to 60 mg/m2/72 h every 4 weeks. Eleven patients enroled in this study and received a total of 30 courses of lobaplatin (median 2; range 1-6). Thrombocytopenia was the dose-limiting toxicity, it reached WHO grade III in three out of six patients at 45 mg/m2/72 h, and WHO grade IV in two out of two patients at 60 mg/m2/72 h. Leucocytopenia was mild, as was nausea and vomiting. Phlebitis at the infusion site was found in three patients. During this trial there were no signs of renal, neuro- or ototoxicity. One patient with ovarian cancer, pretreated with three different platinum complexes, achieved a partial response now lasting for longer than 6 months. In conclusion, thrombocytopenia is the dose-limiting toxicity of lobaplatin administered by 72 h continuous infusion. The recommended phase II dose for this regimen is 45 mg/m2/72 h every 4 weeks.

Stability of the new anticancer platinum analogue 1,2-diaminomethyl-cyclobutane-platinum(II)-lactate (lobaplatin; D19466) in intravenous solutions.

The chemical stability of the new anticancer platinum analogue 1,2-diaminomethyl-cyclobutane-platinum(II)-lactate (D19466) in infusion media was studied in an accelerated stability testing experiment with a selective HPLC-UV method. Variables were time, temperature, light, concentration, and infusion mixture. Mean reaction rate constants of decomposition were, respectively, 0.9555 *10(-2), 2.127 *10(-2), and 4.221 *10(-2) hr-1 at 37, 56, and 66 degrees C at a concentration of 200 mg/L in normal saline. From the Arrhenius equation, shelf lives (5% loss) at 4, 22, 37, and 121 degrees C were, respectively, calculated to be 41.6, 13.2, 5.7, and 0.15 hr. Mean reaction rate constant in 5% dextrose was 3.106 *10(-2) hr-1 (200 mg/L; 56 degrees C) and differed from that in normal saline (P less than 0.005). Mean reaction rate constant in Ringer lactate was 2.084 *10(-2) hr-1 (200 mg/L; 56 degrees C) (P greater than 0.05). There was no influence of normal daylight on the rate of decomposition. It is recommended to prepare D19466 infusions in normal saline. Chemical stability is then maximal 12 hr at room temperature or 24 hr at 4 degrees C. No protection against normal daylight is required. Sterilization by heat is not possible.

A phase I study of 1,2-diamminomethyl-cyclobutane-platinum (II)-lactate (D-19466; lobaplatin) administered daily for 5 days.

A phase I trial was conducted with lobaplatin (D-19466; 1,2-diamminomethyl-cyclobutane-platinum (II)-lactate) i.v. bolus daily for 5 days every 4 weeks. After entering five patients toxicity appeared to be related to renal function, therefore the individual dose (total dose 20-100 mg m-2 over 5 days) of lobaplatin was modified according to creatinine clearance (CRCL) and escalated in patients. Twenty-seven patients with refractory solid tumours received 72 courses. Thrombocytopenia was dose-limiting, its degree was related to dose and CRCL at time of drug administration. With a CRCL of 60-80 ml min-1 the maximum tolerated dose was 40 mg m-2, with a CRCL of 81-100 ml min-1 70 mg m-2, and with a CRCL > 100 ml min-1 it was 85 mg m-2. Platelet and leukocyte nadirs were observed around day 21. The percentual platelet nadir (percentage of day 1 platelet count) correlated with CRCL at different dose levels and could be described by 0.76 x CRCL (ml min-1) - (1.45 x dose (mg m-2) + 43.38. This equation tested in 20 patients (28 courses) produced a correlation between observed and predicted percentual platelet nadir (r = 0.82, P < 0.001). No renal function impairment occurred. Urinary excretion of platinum (by A.A.S) was estimated in six patients and revealed that 91.5% (s.e. +/- 7.9) of the platinum dose was excreted within 4 h. Responses (one PR, one CR) occurred in two patients with ovarian cancer (both pretreated with carboplatin and cisplatin). The recommended dose of lobaplatin i.v. bolus daily for 5 days for phase II studies depends on renal function, namely 30 mg m-2 at CRCL 60-80 ml min-1; 55 mg m-2 at CRCL 81-100 ml min-1; 70 mg m-2 at CRCL > 100 ml min-1.