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To explore whether the tumour bed effect (TBE) in FaDu squamous cell carcinoma growing in nude mice is caused by a reduced tumour cell production rate and/or by increased tumour cell loss.Human FaDu tumours were studied in NMRI nude mice. The volume doubling time (VDT) between 100 and 400 mm3 was determined for tumours in unirradiated subcutaneous (sc) tissues (group 1), tumours in sc tissues preirradiated with 12.5 Gy (group 2), tumours irradiated in situ with 12.5 Gy (group 3), and tumours from group 3 re-transplanted into unirradiated sc tissues (group 4). Labelling index (LI), potential doubling time (Tpot), relative necrotic area and apoptotic index (AI) were evaluated in tumours from groups 1 and 2.The median VDT were 2.6 days (95% CI 2-4) in group 1 and 7.0 days (4-15) in group 2 (p0.001). The VDT were not significantly different between groups 2 and 3, and group 1 and 4. In groups 1 and 2, the Tpot values (3.1 +/- 0.6 days (SD) versus 2.9 +/- 0.5 days) and the LI were identical (10 +/- 1.5%). The median relative necrotic area was significantly larger in group 2 (37% [23-42]) compared with group (6% [0.3-27]). The apoptotic index was low (0.2%) and did not differ between groups 1 and 2.The results indicate that the TBE in FaDu squamous cell carcinoma is not caused by a reduced cell production rate in the viable tumour compartment. Rather, the TBE reflects a decreased viable tumour cell compartment due to increased cell loss. Necrosis appears to be the major component of the tumour bed induced cell loss in FaDu tumours, whereas apoptosis has no impact on the TBE in this model.

Plasma membrane fluidity of intact peripheral blood lymphocytes (PBL) of phenytoin-treated nonepileptic patients and phenytoin-treated CD4 + lymphoid cells H9 and K37 was determined by fluorescence anisotropy measurements. Anisotropy values of the membrane probe 6-(9-anthroyloxy) stearic acid were decreased in all cell types as compared with controls, indicating increased plasma membrane fluidity of phenytoin-treated cells. Specific binding of 125 I-labeled vasoactive intestinal peptide (VIP) to its cellular receptor CD4 on PBL was decreased in PBL of phenytoin-treated patients as compared with untreated, healthy subjects. Adsorption of a different ligand to the CD4 receptor on PBL, the human immunodeficiency virus type 1 (HIV-1), was likewise abolished to PBL of phenytoin-treated patients and phenytoin-treated CD4 + H9 and K37 cells, as assessed by indirect immunofluorescence. Subsequent HIV-1 infection of phenytoin-treated H9 and K37 cells was reduced as measured by indirect immunofluorescence and p24 antigen production. These data indicate that CD4 receptor availability for VIP and HIV-1 was reduced in phenytoin-treated cells. Using the DNA-specific dye Hoechst 33258, we examined cell cycle phase distributions of HIV-1 adsorbing and nonadsorbing H9 cells, as separated by flow cytometry. The majority of HIV-1 adsorbing cells were found to be in the G 2 /M phase, while nonadsorbing cells were mainly in the G 0 G 1 phase, during which plasma membrane fluidity is supposed to be increased. This study indicates that plasma membrane fluidization by phenytoin may serve to disrupt CD4 receptor function and emphasizes the impact of plasma membrane properties on HIV-1 adsorption and infection.

TNF-alpha is a potent inducer of apoptosis and also affects the transit of cells through the phases of the cell cycle. It is thought that the proliferation signalling pathway is related to the apoptosis pathway, the details of this cross-talk are not yet fully understood. In this report, the effects of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on human tumour cell lines with respect to proliferation and apoptosis are examined. The TNF-alpha-sensitive cell lines Me-180 and MCF-7, the resistant cell line TCC-Sup, and the intermediate line 5637 were used. After a one day treatment, the transit through all phases of the cell cycle slowed down and after 3 days stopped completely, as measured with the BrdU-assay and flow cytometry. During the same time however, the levels of c-Myc and Ki-67 expression and the number of cells becoming apoptotic increased. Combined treatment with TNF-alpha and IFN-gamma augmented both the effects on the cell cycle and on apoptosis in the sensitive lines, and had only a minor additional effect on the resistant cell line as compared to single TNF-alpha treatment. The cells becoming apoptotic detached from the culture flask bottom and floated in the medium. Several apoptosis assays were used to prove that the floating cells were indeed apoptotic. As a subsidiary result of receptor measurement, we observed complexes of TNF-alpha receptors I with TNF-alpha receptors II using the related blocking antibodies and I125-TNF-alpha as ligand. The association of proliferative parameters and apoptosis became obvious by plotting the levels of c-Myc expression versus remaining live cells after apoptotic cells were detached. Our data revealed a good linear correlation indicating that high levels of c-Myc render cells sensitive to apoptosis, independent of the treatment, TNF-alpha alone or TNF-alpha in combination with IFN-gamma. The quantitative linear correlation may point to a threshold mechanism.

Cell kinetics of human renal cell carcinomas xenotransplanted into nu/nu mice were analysed using the bromodeoxyuridine (BrdUrd) labelling method. Tumours were removed 0.5-14 h after injection of the BrdUrd solution. The tumour cells were stained with fluorescein isothiocyanate conjugated anti-BrdUrd antibodies and propidium iodide (DNA content). From the flow cytometry data the relative movement was calculated. Relative movement data of variable intervals after BrdUrd labelling were subjected to a fit procedure using log-normal distributions for S phase transition (T(s)). The log-normal distributions were modified by inflation factors in order to get extremely asymmetric distributions. The best fits to the experimental data were obtained using wide asymmetric T(s) distributions, indicating that progression through S phase in solid human tumours is considerably heterogeneous. This implies that the potential doubling time (T(pot)) is longer than calculated from a single measured relative movement value obtained a few hours after BrdUrd labelling.

A human renal cell carcinoma serially transplanted into nude mice was treated with recombinant human tumor necrosis factor alpha (TNF-alpha), recombinant human alpha interferon (IFN-alpha), and a combination of both. All treatments resulted in a significantly reduced tumor growth. The greatest effect was obtained with the combination of TNF-alpha and IFN-alpha. This latter treatment completely eradicated tumors which were smaller than 50 mm3 at the beginning of treatment. Cell kinetic analysis using the bromodeoxyuridine technique and flow cytometry revealed a prolongation of the transition time through S-phase from 7.9 h in the case of control tumors to 10.5 h for tumors treated with IFN-alpha and TNF-alpha. Single treatment with either TNF-alpha or IFN-alpha had only minor effects. The bromodeoxyuridine labeling index was unaffected by IFN-alpha (16.6%; control, 15.2%) but was reduced to 12.1 and 11.7% when tumors were treated with TNF-alpha and IFN-alpha plus TNF-alpha, respectively. The calculated potential doubling times were 2.3 and 2.8 days, respectively, for tumors treated with TNF-alpha or IFN-alpha plus TNF-alpha. When treated with IFN-alpha, the potential doubling time (1.7 days) was similar to that of the control (1.6 days), indicating that the main effect of TNF-alpha was antiproliferative. Conversely, the calculated cell loss factors increased after IFN-alpha and combined treatment but not after TNF-alpha treatment. Combined treatment augmented cytotoxicity, but the cell kinetic characteristics of surviving cells remained similar to those of tumors treated with TNF-alpha alone. Histological analysis showed a distinctly reduced mitotic activity but no coagulative necroses after treatment with TNF-alpha. IFN-alpha and, in particular, IFN-alpha plus TNF-alpha induced cytoplasmic vacuolization, nuclear pyknosis, and cell death, which resulted in tumor regression. These data suggest that, in this particular tumor model, TNF-alpha produces mainly antiproliferative effects, whereas IFN-alpha acts via cytotoxic mechanisms.

The effects of mitomycin C (MTC) alone and in combination with radiation on R1H rhabdomyosarcomas in WAG/Rij rats were studied. Growth delay was determined from tumor volume growth curves and proportion of tumor and host cells from flow cytometry measurements. Only minor growth delays were obtained with MTC at doses near the toxic level while irradiation applied in three fractions of 10 Gy in three weeks yielded growth delays of 27, 44, and 51 days measured at volumes of 2, 5, and 10 cm3, respectively. The combination of 1 micrograms/kg b.w. MTC and 10 Gy irradiation given in three weekly fractions resulted in 21, 28, and 29 days growth delay for the above tumor volumes. The lower effect of combination as compared to irradiation alone is discussed with the flow cytometry data. These data show that early after start of treatment the proportion of tumor cells remains constant in contrast to radiation alone where the fraction of tumor cells decreases because of influx of granulocytes and macrophages into the tumor. In contrast to the reduced effect on tumors the combination treatment was considerably more toxic for the animals than the single treatments.

The effect of the activated c-Ha-ras oncogene on invasiveness and formation of spontaneous metastases was studied using the rhabdomyosarcoma R1H of the rat. R1H tumor cells which are able to grow in vitro and produce tumors upon subcutaneous injection in syngeneic WAG/Rij rats were transfected with the c-Ha-ras (EJ) oncogene and the neomycin gene for selection. Two R1H cell lines harboring and expressing the human c-Ha-ras oncogene, one cell line containing the neomycin gene only, and the parent R1H cell line were compared. The expression of the transfected c-Ha-ras oncogene was assessed by Northern blot analysis and by flow cytometry using antibodies against ras p21. No difference in tumor growth rate and morphology was observed for the transfected and untransfected cell lines. Tumor volume doubling time was about 2 days in R1H-ras as well as in R1H parent tumors. Formation of spontaneous metastases was tested by excising the tumors when they had reached a volume of 2 cm3; after that the animals were observed up to 12 months. The excised tumors still contained and expressed the transfected ras oncogene as proved by Southern blot analysis and antibody staining using anti-ras p21. In contrast to most previous work on ras-transfected tumorigenic cells the R1H-ras tumors did not acquire invasive growth potential or increased metastatic capacity.

Der Einsatz von Interferonen und anderen Zytokinen in der Therapie maligner Tumoren impliziert die Notwendigkeit zur Etablierung eines geeigneten praklinischen Testmodelles. Nur so konnen fur die klinische Testung die notwendigen Studienbedingungen festgelegt werden, in deren Rahmen eine erfolgreiche Tumortherapie erwartet werden kann. Ein verlasliches praklinisches Testmodell kann also die Zahl unnotiger, da aufgrund eines falschen Designs erfolgloser Studien reduzieren und verhindert, das Zytokine fur die Therapie spezieller Tumoren verworfen werden, nur weil inadaquate Dosierungs-, Fraktionierungs- und Applikationsschemata verwendet wurden.

In a variety of lymphocyte interactions, lymphocyte function-associated antigen-1 (LFA-1) plays an important role as an accessory mechanism mediating cell adhesion. We tested the possibility that LFA-1 could also be involved in the specific binding of lymphocytes to high endothelial venules (HEV) during homing. Antibodies against LFA-1 but not against various other cell surface molecules (except the putative gp90 homing receptor defined by the MEL-14 antibody) were found to inhibit in vitro adherence of lymphocytes to HEV in frozen sections of lymph nodes. Binding of T cell lines to HEV was also inhibited by anti-LFA-1 antibody. Using sublines selected for differential expression of the MEL-14 antigen, MEL-14 high cells (which bind well to HEV) were less susceptible to inhibition by anti-LFA-1 than poor binders with low levels of the homing receptor, supporting the model of LFA-1 being an accessory mechanism strengthening weak interactions between cells. Parallel results were found in vivo where anti-LFA-1 antibodies reduced the migration of normal lymphocytes into lymph nodes and Peyer's patches by 40 to 60%. Localization in the lung, especially of activated lymphocytes, was also impaired, although to a lesser extent. These findings suggest that LFA-1 plays an accessory role in cellular interactions relevant for lymphocyte migration.

The total hadronic γ-proton cross section has been measured for photon energies between 0.5 and 5.0 GeV. For this measurement the primary photon energy of photoproduction events in a hydrogen bubble chamber was determined by a counter arrangement.

Unter den exokrinen Pankreasneoplasmen ist das duktale Adenocarcinom mit einer relativen Haufigkeit von 80–90% der vorherrschende Tumor (1). Durch seine generell schlechte Prognose, nur etwa 2% der behandelten Patienten uberleben die Funfjahresgrenze (2) und seine langsam zunehmende Incidenz in den letzten 20 Jahren (3), ist das duktale Pankreascarcinom zu einer grosen Herausforderung in der Onkologie geworden. An einem geeigneten Tumormodell wie dem “Nacktmaussystem” konnten Tumorbiologie, Tumorwachstum und pratherapeutische Therapiestudien untersucht werden. In der vorliegenden Arbeit sollte zunachst uberpruft werden, inwieweit das Wachstumsverhalten duktaler Pankreascarcinome auf der Nacktmaus dem Wachstum dieser Tumorart beim Menschen entspricht und von welchen morphologischen und tumorbiologischen Kriterien die Wachstumsgeschwindigkeit abhangt.

In der vorliegenden Studie wird der Wert dreier Methoden zur Diagnose des Harnblasenkarzinoms anhand von Harnuntersuchungen uberpruft: Die herkommliche Zytologie, die Immunzytologie mit Hilfe des eigenen monoklonalen Antikorpers 486 p 3/12 und die Flowzytometrie. In einer prospektiven Studie werden die Ergebnisse von 69 parallel untersuchten Blasentumorpatienten und von 35 Kontrollpatienten (11 mit Harnwegsinfekten und 24 mit Prostataadenom) analysiert, die in jeweiliger Unkenntnis der Diagnose dieser Patienten erstellt wurden.

The influence of three chemotherapeutic agents, acronycine, bleomycin and cytosine arabinoside, alone and combined with radiation, on cell cycle progression and viability of L-cells was examined. The percentages of cells in G1, S and (G2 + M)-phases as derived from pulse cytophotometric DNA distribution patterns were recorded as a function of exposure time. After 24-h treatment with 10 microgram/ml acronycine, 46.4% of cells were accumulated in (G2 + M)-phase compared to 12.1% in the controls. This accumulation was significantly enhanced by an irradiation with 150 rads of X-rays resulting in arresting 63.1% of cells in this phase. Similar findings were obtained after a 24-h treatment with 100 microgram/ml bleomycin. 54.4% of cells were arrested in (G2 + M)-phase by the chemical treatment alone, while the combined treatment, bleomycin and radiation, yielded an accumulation of 66.3% of cells in G2 + M. A 24-h exposure to 0.2 microgram/ml cytosine arabinoside (Ara-C) produced a reversible block of 72.8% of cells in S phase compared to 27.4% in the control cultures. This S block was less pronounced after the combined treatment (51.1%). Some implications of the results for combined therapy are discussed.

Adult rat hepatocytes multiply in primary cultures when incubated in arginine-free MX-83 medium supplemented with dialyzed fetal calf serum, insulin, glucagon, hydrocortisone, epidermal growth factor, and transferrin. In the absence of mitogens, the fraction of the cells engaged in DNA synthesis dropped sharply. However, cells initiated DNA synthesis in response to the mitogenic mixture indicating that hepatocyte proliferation is controlled by G1----S transition rates. In contrast, rat hepatoma line DTH-3, derived from Morris 7777 "minimal deviation" hepatoma, required only insulin for proliferation in chemically defined MX-83 medium. The lengths of their cell cycle phases varied with the growth rate. The phases of the growth cycle were proportionately shortened (expanded) when the growth rate was increased (decreased). It is concluded that DTH-3 hepatoma cells, which display a decreased growth factor requirement as compared with adult rat hepatocytes differ from normal hepatocytes by fundamental alterations in the mechanisms controlling the progression of the cell cycle.

The effect of irradiation on the permeability of cell membranes of L-929 cells was investigated. Efflux of fluorescein, accumulated by hydrolysis of fluoresceindiacetate in the cells, was measured using flow cytometry. The changes of rate constants for the permeation of florescein through the cell membrane at different temperatures and after various X-ray doses were studied. Decreasing temperatures yielded substantially slower efflux of fluorescein. After irradiation of cells, the rate constant of fluorescein efflux increased linearly with dose; 180 Gy are required to cause an increase by a factor of 2. The results are discussed with respect to radiation damage of active and passive transport mechanisms.

Thirty human renal cell carcinomas, subpassaged into NMRI-nu/nu mice, were analyzed during long term serial transplantation (range, 10-50 passages) with regard to their histological differentiation, mitotic activity, and DNA content. A quantitative methodology was applied to determine the mitotic rate. The DNA content was measured by flow cytometry. Only five tumors (four primaries and one metastasis) changed their mitotic rate significantly (P less than 0.01). In each case this change was paralleled by a simultaneous alteration of the DNA content. Histological pattern and nuclear grade remained stable in all but one tumor where the change in histological pattern occurred simultaneously with changes in DNA index and mitotic rate. These results indicate that the majority of renal cell carcinomas remain stable during long term serial transplantation, at least with regard to the parameters examined. This is a basic prerequisite for making the grafting of renal cell carcinomas into nude mice a reliable in vivo model for drug sensitivity testing. However, since a few of the transplanted tumors showed instability, continuous monitoring of phenotypic and genotypic tumor features is necessary during long term xenotransplantation.

Up to now no age-correlated normal values of normal and modified nucleobases in urine have been published. In this paper such normal values are presented, obtained from 116 healthy subjects from 0 to 16 years by high performance liquid chromatography of creatinine-correlated single urine specimens. A narrow correlation between the excretion of nucleobases and growth velocity was found. A polynomial function including the puberal growth spurt could be fitted to the analytical data. It is felt that this method should be suitable to assess growth processes of different kinds, e.g. effects of nutrition or drugs and hormones on growth velocity, furthermore intrauterine and malignant growth.

1 – 4% aller Patienten mit einem ductalen Pankreascarcinom uberleben 5 Jahre. Fur die bis zu 90% inoperablen Falle gibt es bis heute keine wirklich lebensverlangernde Therapie. Daher ist die schnelle und konsequente Erforschung von potenten Chemotherapeutica und Chemotherapieregimen fur das Pankreascarcinom dringend erforderlich. In der vorliegenden Arbeit soll daher die Durchfuhrbarkeit von Cytostaticasensibilitatstests fur das ductale menschliche Pankreascarcinom im Nacktmaussystem, im Hemmtest mit radioaktiv markierten DNA/RNA-Vorlaufern sowie im Stammzellassay untersucht werden.

The authors investigate if cytometric parameters can be used for discerning malignant and benign tumors as well as for the prognostic classification of malignant tumors. Measures on leukemias, brain and prostate tumors, colorectal carcinomas, and renal carcinomas taken by some study groups of the Institute of Biophysics and Radiobiology are cited and discussed with respect to the above mentioned aspects. The analysis showed that fractions of cells in phases of the cellular cycle as indicators of the proliferation rate are only of little diagnostic value because of the too great zone of dispersion. Especially the differentiation between benign and malignant tumors is not clear enough. In case of renal carcinomas, however, there is a marked correlation between prognosis and aneuploidy measured by cytometry. Thus the DNA index as a quantitative parameter of aneuploidy seems to be also of clinical interest for the determination of malignancy.

The combined action of Daunomycin and irradiation was investigated using mouse L-929 cells in culture. Survival of cells was measured with the colony assay. Sedimentation in alkaline sucrose gradients was used to study repair of DNA single-strand breaks (SSB) in the presence of various concentrations of Daunomycin. A small increase in radio-sensitivity, as measured by decreasing Do, was obtained for doses of Daunomycin that are considerably toxic to the cells (0.1 microgram/ml). However, the Dq values remained constant even at high concentrations indicating that Daunomycin does not interfere with recovery processes. The rate of rejoining of SSB remained constant up to 1.0 microgram/ml, whereas concentrations of Daunomycin as high as 10 microgram/ml reduced the velocity of repair by a factor of 13. Our data show that concentrations of Daunomycin similar to those required for other DNA-binding drugs are required to inhibit SSB repair. For clinical purposes, no increase in tumour-killing efficiency may be expected from a combined treatment with Daunomycin and radiation.

Bei 76 konsekutiven Patienten mit einem Nierenkarzinom im Stadium I bis III nach Robson haben wir Tumorgewebe fluscytometrisch untersucht. Dabei erweisen sich die Ergebnisse der fluscytometrischen Untersuchung des Tumorgewebes als bemerkenswerter prognostischer Parameter.

The qualitative and quantitative analysis by high performance liquid chromatography of the normal and modified nucleobases excreted in urine represents a new and versatile tool. Its use for the diagnosis of malignancies, deliminating infectious diseases, and for the follow-up of the effects of a cytostatic therapy is shown. This method offers a chance to introduce the analysis of a series of fragments of primary gene products into the routine of clinical biochemistry.

One-parameter (nuclear DNA) and two-parameter (nuclear DNA and protein or cellular light scatter) measurements of cervical smears were performed using an ICP 11 and a cytofluorograf 4800 respectively. A total of about 1000 cases was analyzed. For the estimation of nuclear DNA alone two fluorochromes were tested (ethidium bromide (EB) and mithramycin (MMC)) combined with three different methods of cell preparation. For the two-parameter measurements cells were double stained with EB and fluorescein isothiocyanate (FITC). Red fluorescence (EB) versus green fluorescence (FITC) or red fluorescence versus scatter were recorded. A computer analysis of the one-parameter histograms was performed using discriminant analysis and the results were compared with the cytodiagnosis of microscopic specimens stained with the Papanicolaou technique. The error rates of the flow cytometric (FCM) data were as follows: (a) standard EB staining, 11% false negative, 26% false positive, 6% unsatisfactory results; (b) pepsination of vital cells and EB staining, 12% false negative, 14% false positive and 4% unsatisfactory results; (c) MMC staining, 10% false negative, 65% false positive and 5% unsatisfactory results. Our two-parameter measurements prove that, as confirmed by cell sorting, red fluorescence versus scatter allows separation of at least three subpopulations in most analyzed samples: (a) anucleated cells; (b) leukocytes; and (c) intermediate and superficial cells.

The qualitative and quantitative analysis by high performance liquid chromatography of the normal and modiefied nucleobases excreted in urine represents a new and versatile tool, especially in oncology. The excretion of 2 normal (adenine, guanine) and 4 modified nucleobases (methylated guanine derivatives) in urine was measured by cation exchange LC. All chronic myeloproliferative syndromes showed highly elevated total excretion values of all determined nucleobases, the "pattern" being characteristic with N2, N2-dimethylguanine most prominent (up to 29.8 S.D. above the pertinent normal value). A follow-up study of a case of CML with two episodes of extreme leukocytosis showed a correlation of the nucleobases excretion with the number of leukocytes. Thus, a method has been established which permits the assessment of myeloproliferation and probably therapy effects.

Nach Ureterosigmoidostomie (UST) wurde bis 1986 uber 79 im Anastomosenbereich entstandene Adenocarcinome berichtet. Zwei entsprechende Carcinome sind im Colon-Conduit, vier im Ileum-Conduit beschrieben [6, 10]. Die Carcinomentstehung, insbesondere nach Ureterosigmoidostomie, wird meist auf eine durch gemeinsame Ableitung von Stuhl und Urin induzierte endogene Nitrosaminsynthese im Darm zuruckgefuhrt [9]. Crissey [3, 4] beschrieb 1980 in einem von ihm inaugurierten Rattenmodell in 66% eine Carcinomentstehung bei gemeinsamer Ableitung von Urin und Stuhl im Darm. Die Latenzzeit betrug 8–11 Monate. Bei Gittes [5] entstanden bei der Weiterfuhrung dieses Modells in 80% Carcinome nach 8–12 Monaten. Dieses Modell ist von der operativen Technik her kaum mit der beim Menschen durchgefuhrten Ureterosigmoidostomie zu vergleichen, da die gesamte Blase divertikelartig mit dem Colon anastomisiert wurde. Auf andere eventuell mitauslosende Ursachen der Carcinomentstehung — wie z. B. den durch die hyperchloramische Azidose alterierten Stoffwechsel [1, 2, 7, 8] — wurde bisher nicht eingegangen.

Twelve methods for analysing FCM-histograms were compared using the same set of data. Some of the histograms that were analysed were simulated by computer and some were taken from experiments. Simulated data were generated assuming asynchronously growing cell populations and (i) measurement coefficients of variation (CV) from 2 to 16%; (ii) constant measurement CV or CV's increasing from G1 to G2 phase, and (iii) varying fractions of cells in each phase. Simulated data were also generated assuming synchronous cell populations in which a block in early S phase was applied and released. DNA histograms were measured for L-929 cells at various times after mitotic selection. Labelling indices were also measured for these cells at the same time. The fractions of cells in the G1, S, and (G2+ M) phases were calculated by each analytical method and compared with the actual fractions used for simulation, or in case of experimental data, with autoradiographic results. Generally, all methods yielded reasonably accurate fractions of cells in each phase with relative errors in the range of 10–20%. However, most methods tended to overestimate G1 fractions and underestimate S fractions. In addition, variations in the shape of the S phase distribution often caused considerable errors. Phase fractions were also calculated for histograms of kinetically perturbed populations, simulated as well as experimental The errors were only slightly larger than for histograms from asynchronously growing cell populations.

Thirty human renal cell carcinomas were transplanted into NMRI (nu/nu) mice. The take rate from surgical specimens was 100%, and all tumors were established as permanent transplantable tumor lines. The xenotransplants were followed up to around passages 10-50. In addition to histology and volume growth the DNA indices (DI), proportion of tumor cells, and fractions of cells in the phases of the cycle were measured by flow cytometry. All 30 tumors retained their primary histologic structure and cellular morphology throughout all passages. The DI, as ascertained by the DNA content per cell of G1-phase tumor cells divided by the DNA content per cell of normal diploid G1-phase cells, remained the same as those in the original tumors in 21 of 27 xenotransplants. Three original lymph nodes or metastases were not available for flow cytometry. During passage, 4 of 30 tumors changed their DI. In 2 of these cases the tumor doubling time (td), the proportion of tumor cells versus the proportion of host cells, and the fractions of cells in the cell cycle phases changed simultaneously. All other tumor lines were stable in td, DI, proportion of tumor cells, and fractions of cells in the phases during serial transplantation. However, the measure of parameters varied considerably between individual tumors of every passage. Tumor growth rate was generally related to the prognosis of the patients from whom the tumor was derived.

128 tumors from three different human renal-cell carcinomas and from one human transitional bladder cancer were transplanted into NMRI mice treated with cyclosporin A at various dosages. Their acceptance rate, proliferation rate, and morphologic and growth characteristics were studied and compared with those of the same human tumors after transplantation into NMRI nu/nu mice. The acceptance rate was 80% in mice treated with cyclosporin A at 100 mg/kg-1 and 150 mg/kg-1/day. The highest acceptance rate was observed after transplantation into nu/nu (thymus-aplastic) mice (100%). Morphologically, the transplanted tumor was similar in the two animal groups and identical with the primary tumors. Metastases were not seen in either animal model. The NMRI mice treated with cyclosporin A had leukocyte infiltration into the transplanted tumor. The growth rate of the human tumors in normal mice depended on the cyclosporin A dosage, and was highest in the nu/nu mice. The proliferation rates of the transplanted human tumors, as judged by flow cytometry, were rather similar in all groups.

A retrospective study of 95 follicular thyroid carcinomas was conducted to evaluate the prognostic value of different morphological and clinical features. The biological behaviour of these tumours was primarily influenced by presence or absence of a capsule type of confinement: the frequency of lethal outcome among widely invasive carcinomas was six times higher than among encapsulated neoplasms. Furthermore, dismal prognosis could be demonstrated for tumours occurring in older patients (with a sharp break in the prognosis at the age of 52 years) and for those lesions which displayed oxyphilic metaplasia. The same effect was shown for presence of lymph node metastasis, tumour invasion of the cervical soft tissue and, for the case of encapsulated carcinomas, distant haematogenous spread. Conversely, the degree of differentiation and the patients' sex proved to have no significant influence on prognosis. In 22 carcinomas, cytophotometric and flow-cytometric determinations of DNA values were performed. These procedures revealed to have only limited diagnostic value, since for the majority of the tumours, benignancy or malignancy could not be judged from the DNA histograms. However, DNA measurements proved to contribute valuable information for the prognosis in individual cases of widely invasive follicular carcinomas. The discussion focuses on the diagnostic, therapeutic and prognostic relevance of these findings and on their impact on subclassification of follicular thyroid carcinomas.

Individual properties of gynecologic specimens can produce artifacts in flow cytometric (FMC) measurements, possibly leading to false interpretations. An identification of such artifacts was undertaken by parallel FCM and microscopic investigations. One hundred fifty unselected cervical smears were measured by FCM using the fluorochromes 4'-6-diamidino-2-phenylindole (DAPI) for DNA and sulforhodamine (SR 101) for protein. Microscopic specimens were stained by the Papanicolaou technique, and a detailed cytogram was prepared from each smear. FCM discrimination of fluorochrome-stained superficial and intermediate cells was very difficult. On the other hand, a correlation could be established between the fraction of cells from the deeper epithelial layers in the microscopic cytogram and the mean protein content in the FCM histogram. Furthermore, the role of microorganism could be elucidated. Some microorganisms may produce a reduction of the protein content by cytolytic changes. Other microorganisms adhere to the cell surface, resulting in a misleading increase of the DNA fluorescence. Implications for the problem of false alarms are discussed.

Die Transplantation von menschlichem Karzinomgewebe auf Nacktmause hat unter anderem dazu beigetragen, Cytostatika auszutesten (Otto et al. 1984 a; Otto et al. 1984 b; Otto et al. 1985). Uber die Transplantation von menschlichem Blasenkarzinomgewebe gibt es nur wenige Berichte (Sufrin et al. 1979; Matthews et al. 1982), insbesondere liegen keine langeren Verlaufsbeobachtungen vor (Fogh). Unsere Erfahrungen mit der Transplantation von menschlichem Nierenkarzinomgewebe haben gezeigt, das eine nahezu 100%ige Angehrate der transplantierten Tumoren zu erzielen ist, das Transplantat- und Primartumor identisch sind, das eine enge Korrelation zwischen Wachstumsverhalten der Tumoren auf der Nacktmaus und dem klinischen Verlauf der korrespondierenden Patienten besteht und das Cytostatikaaustestungen auf den Patienten ubertragbar sind. Dies war Voraussetzung fur eine erfolgreiche patientenspezifische Tumortherapie.

Growth and differentiation processes are accompanied by an altered turnover of nucleic acids. In contrast to their major constituents, the modified nucleosides and nucleobases as minor nucleic acids components cannot be recycled. Only part of them can be catabolized. So the quantity and pattern of their excretion in urine represent new indicators of growth and differentiation. Normal and modified nucleobases and nucleosides are measured at the picomole level by cation exchange HPLC. Plotted against age, the excretion curves of the modified nucleobases and nucleosides are in accordance with the shape of the known growth velocity curve. As a consequence of the organ specific nucleic acid equipment and the varying relative growth velocity of specific organs, the nucleobase excretion patterns of young children differ significantly from those of older ones. When adequately age-correlated,many children and adults with different malignancies show significant quantitative and qualitative aberrations in their urinary nucleobase pattern. These are normalized by a successful cytostatic therapy. So, the outlined principle and method should be well suited to follow normal and malignant growth and differentiation processes.