Establishment of a near-tetraploid B-cell lymphoma line with duplication of the 8;14 translocation

The neoplastic cells of a patient with diffuse histiocytic lymphoma were grown in three systems: Soft agar, liquid culture, and by heterotransplantation into the nude mouse. In each case, the growing cells were shown to bear the same immunoglobulin heavy and light chain type as the original neoplastic cells (IgM-lambda). In both the liquid culture and nude mouse heterotransplant tumors, karyotypic analysis revealed the presence of pseudodiploid and near-tetraploid metaphases bearing one and two copies of an 8;14 translocation, respectively. From the liquid culture separate clones of pseudodiploid and near-tetraploid cells were isolated in soft agar, and separate cell lines SK-DHL2A and SK-DHL2B were established. Studies comparing the proliferative characteristics of the two lines showed no difference in cell population doubling time or clonigenicity in soft agar. Hence, the presence of two copies of the translocated material did not confer a proliferative advantage on cells containing it. Theses lines may be valuable in future studies of cell proliferation and oncogenesis in the human immune system.

Factors modifying the synergistic toxicity of deoxycytidine in combination with thymidine plus 5-fluorouracil in HeLa cells

We reported previously that deoxycytidine (CdR) enhances the cytotoxic effects of the drug combination thymidine (TdR) plus 5-fluorouracil (FUra) against HeLa S-3 cells. We have now examined the relationships between the concentration of CdR and its cytotoxic and cytokinetic effects, and have also investigated the role of certain other components of the culture medium in this phenomenon. Cell survival was determined by a colony-forming assay; cytokinetic effects were monitored by flow cytometry. In the initial experiments, cells were grown in Ham's F12 medium and exposed for 22 hr to 4 mM TdR, 0 X 025 mM FUra, and dCyd ranging from 1 microM to 4 X 0 mM. The individual drugs were at most only slightly toxic under these conditions; for TdR plus FUra, the survival decreased to 50% (in 5% FCS), and in the three-drug combination it varied from 8% at 1 microM CdR to 28% at 0 X 10 mM and back to a low of 3% at 4 X 0 mM CdR. Results from flow cytometry appeared correlated with the survival data, in that cells accumulated in the S phase to a greater extent in the region around 0 X 10 mM CdR than at higher or lower concentrations. When cells were exposed to the drugs in MEM medium in place of F12, their sensitivity to FUra and the TdR-FUra combination was enhanced, although the additional synergistic effect of CdR was reduced. We found that hypoxanthine, present in F12 but not in MEM, was the principal compound responsible for the observed differences between media.

Bactobilin: blue bile pigment isolated from Clostridium tetanomorphum

A blue bile pigment, possessing four acetic and four propionic acid side chains has been isolated from extracts of the anaerobic microorganism Clostridium tetanomorphum and in smaller amounts from Propionibacterium shermanii. The compound could be prepared in larger amounts by incubation of C. tetanomorphum enzyme extracts with added delta-aminolevulinic acid. The ultraviolet-visible, infrared, and proton magnetic resonance spectra of the pigment indicate a chromophore of the biliverdin type. Field-desorption mass spectrometry of the purified methyl ester showed a strong molecular ion at m/e = 962. This corresponds to the molecular weight expected for the octamethyl ester of a bilatriene type of bile pigment structurally derived from uroporphyrin III or I. Of the five possible structures, two could be eliminated by proton magnetic resonance spectroscopy. The name bactobilin is proposed for this previously unreported bile pigment.

Factors affecting the termination of cardiovascular actions of 10,10-difluoro,13-dehydroprostacyclin

Experiments were conducted to determine why 10,10-difluoro,13-dehydroprostacyclin (DF2-PGI2) has a long vascular relaxant activity in vitro but like PGI2 has a short duration of effect in vivo. DF2-PGI2 produced depressor responses in anesthetized dogs which were not affected by nephrectomy suggesting that the kidney was not responsible for the termination of action. DF2-PGI2 given intravenously or into the ascending aorta produced depressor responses of a similar magnitude but injection of the same doses into the hepatic portal circulation resulted in a large attenuation of responses. The data suggest hepatic, but not pulmonary, metabolism of DF2-PGI2. Injection or infusion of PGI2 and DF2-PGI2 into the hindlimb circulation caused vasodilatation of a similar duration suggesting diffusion from tissue sites as another mechanism of termination of action.

Long-acting contraceptive agents: design of the WHO Chemical Synthesis Programme

The great demand for improved long-acting injectable steroid contraceptives, particularly in developing countries, and the relative lack of interest from the pharmaceutical industry to develop such products stimulated WHO to launch a synthetic and screening programme to find improved, safe and acceptable injectable preparations. More than 210 esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) and levonorgestrel (D-(-)-13 beta-ethyl-17 alpha-ethynyl-17 beta-hydroxygon-4-en-3-one) have been prepared in university-based research laboratories situated mainly in developing countries, and then screened by NICHHD in animal models. The following three compounds, levonorgestrel butanoate, cyclopropylcarboxylate and cyclobutylcarboxylate, proved to be particularly long-acting when administered as microcrystalline suspensions. The overall strategy of this research and development programme is described.

Effects of Hoechst 33342 on survival and growth of two tumor cell lines and on hematopoietically normal bone marrow cells

Our objective in this investigation was to determine whether Hoechst 33342, which is widely recognized as a DNA specific fluorochrome for living cells, is in fact nontoxic and kinetically nonperturbing at dye concentrations required to achieve acceptable DNA distributions. Three cell types were tested: HeLa S-3; SK-DHL2, a human lymphoma cell line; and hematopoietically normal human bone marrow cells. In the third system, only the cloning efficiencies were determined. Results differed considerably for the different cell types. While HeLa cells yielded excellent DNA distributions and were almost completely resistant to the cytotoxic and cytokinetic effects of the dye, SK-DHL2 cells were highly sensitive to the fluorochrome even at dye concentrations which produced very poor DNA distributions. Human bone marrow cells were intermediate in their stainability and toxicity response, and acceptable DNA distributions could be obtained at the nontoxic dye concentration of 2.5 muM. Clearly, different cell types differ considerably with respect to their cytotoxic and kinetic responses to Hoechst 33342. In some cases it may not be possible to ensure adequate staining of the cells for flow cytometry without significantly altering their viability and/or proliferative behavior.

A comparison of mathematical methods for the analysis of DNA histograms obtained by flow cytometry

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 synchronously growing cell populations and (i) measurement coefficients of variation (CV) from 2 to 16%; (ii) constant measurement CV or VC'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.

Effects of cytosine arabinoside and daunorubicin on survival and cell cycle progression of Chinese hamster ovary cells

Kinetic and cytotoxic effects of cytosine arabinoside (Ara-C) and daunorubicin (DNR) on exponentially growing Chinese hamster ovary (CHO) cells were measured by flow cytometry and by a colony-forming assay, respectively. With Ara-C alone, increasing drug concentrations between 10(-7) M and 10(-4) M, for up to 27 hr, were associated with increased inhibition of cell progression through the S phase. Even at the very toxic concentration of 10(-4) M, however, cells were able to enter and progress slowly through S. DNR, which appears to enter these cells relatively slowly, was highly toxic even at 2 X 10(-7) M. It decreased the rate of progression through S phase and caused cells to accumulate in G2, except at the highest concentration (2 X 10(-5) M, at which progression was inhibited throughout the cycle. Simultaneous exposure of the cells to Ara-C and DNR yielded cell cycle distributions similar to those of the former drug alone. When cells were exposed to a non-lethal dose of Ara-C and to a dose of DNR which was lethal to a fraction of the cell population (or conversely), either simultaneously or separated by a drug-free interval, small, but in some cases significant, drug interactions were observed. These effects were not caused by drug-induced redistribution of cells within the cell cycle, but may have been related to the effects of the non-lethal drug on DNA synthesis rate.

Cytotoxic and cytokinetic effects of thymidine, 5-fluorouracil, and deoxycytidine on HeLa cells in culture

Exponentially growing HeLa cells were exposed to thymidine (dThd), 5-fluorouracil (FUra), and deoxycytidine (dCyd) singly and in combination for up to 3 days. Survivals were measured using a colony forming assay, and cytokinetic effects of the drugs were evaluated by flow cytometry and by determination of population growth rates. Increasing concentrations of dThd alone (up to 4 mM) progressively slowed the movement of cells through the cycle; dThd was toxic above 1 mM. Nontoxic levels of FUra (10(-5) M) inhibited cell progression, but this was abolished by very low concentrations (3 microM) of dThd. The cytotoxic effects of FUra were not reversed by dThd; in fact, the lethality of FUra was enhanced in some cases. dCyd alone had neither cytotoxic nor cytokinetic effects on HeLa cells up to 4 mM, but low concentrations reversed the cytotoxic effects of 4 mM dThd and high concentrations reversed its cytokinetic effects. When dCyd was added to the combination of dThd and FUra, synergistic lethality resulted even at 10(-5) M FUra. The mechanism by which this synergism was achieved was not simply increased incorporation of FUra into RNA since, while dThd did enhance this incorporation, dCyd did not further increase it. Our results suggest instead that dCyd either directly or indirectly inhibited the repair of FUra-associated damage or else enabled the cells to progress into a more sensitive phase of the cell cycle during exposure.

Hallucinations and delusions in black psychiatric patients

A higher incidence of hallucinations has been previously reported among blacks, as compared to whites, in both psychiatric and nonpsychiatric populations. In contrast to these reports, which relied on hospital records, the present study utilized standardized research rating scales, and confirmed the above observation among schizophrenic patients. Some blacks, irrespective of diagnosis, probably experience a variety of non-schizophrenic hallucinations, may lead to erroneous diagnoses of schizophrenia. Current ignorance regarding the content of hallucinations in normal and non-schizophrenic, and in schizophrenic blacks is a source of diagnostic confusion which may have dire consequences for many individuals.

Relative contracting and relaxing potencies of a series of prostaglandins on isolated canine mesenteric artery strips

The contracting and relaxing potencies of and interactions between a number of prostaglandins (PGs) were studied in vitro on spiral strips of small canine mesenteric arteries (outside diameter less than 1 mm). PGF2 alpha and PGE2, the most potent contracting PGs, were nearly equal in potency (EC50 4 x 10(-7) M) and did not cause relaxation under our experimental conditions. PGI2 and PGE1 were equal and the most potent relaxing PGs (EC50 3 x 10(-9) M). PGE1 also caused contraction, but this effect was not consistent. PGI2 did not cause contraction in concentrations up to 3 x 10(-6) M. In higher concentrations, however, it caused abrupt and near maximal contraction. PGD2 was weak in both respects, causing incomplete relaxation and contraction or biphasic effects. Interaction studies showed that PGE1 and PGI2 mutually excluded the relaxing effects of each other. PGE1 also reversed the relaxing effect of isoproterenol. However, pre-exposure to PGD2 did not attenuate the relaxing effect of PGE1 or PGI2 nor was the relaxing effect of PGD2 changed by pre-exposure to PGE1. Two different orders of potency of PGs suggest two PG receptors subserving contraction and relaxation, respectively. Further, it appears that several PGs can act upon both receptors which may explain unusual interactions between the PGs and some of their atypical effects. Finally, the data also suggest that there may be subtypes of the PG receptors subserving contraction and relaxation.

Cytotoxic and cytokinetic effects of 1-beta-D-arabinofuranosylcytosine, daunorubicin, and 6-thioguanine on HeLa cells in culture

Exponentially growing HeLa cells were exposed to 1-beta-D-arabinofuranosylcytosine, daunorubicin, and 6-thioguanine singly and in combination for 21 hr. Survivals were determined by a colony-counting assay, and cytokinetic effects of the drugs were evaluated by flow cytometry. When used in two-drug combinations (concurrent exposures). 1-beta-D-arabinofuranosylcytosine was found to protect cells against both 6-thioguanine- and daunorubicin-induced lethality, the former to a greater extent than the latter. Protection against 6-thioguanine appeared to be related to the degree of inhibition of DNA synthesis by 1-beta-D-arabinofuranosylcytosine, but this was not the case with daunorubicin. When cells were exposed to the three drugs simultaneously, survivals were in agreement with those predicted from the various two-drug combinations. This implies that no additional drug interactions occurred when a third drug was added to the two-drug combinations.

Kinetic and cytotoxic effects of cytarabine and daunorubicin on cells in culture

To investigate the possibility that a significant kinetic basis exists for the improved clinical response often obtained using drug combinations, Chinese hamster ovary cells were exposed to cytarabine and daunorubicin in combination. Cell survival was determined by a colony-counting assay; kinetic perturbations were monitored by flow cytometry. No major synergistic effects of the conditions, each drug appeared to provide some protection against the lethal effects of the other. By pairing a moderately toxic concentration of one drug with a nontoxic concentration of the other, we observed sequence-dependent differences in survival. These differences could not be attributed simple to alteration of the cell cycle phase positions by the nontoxic drug, combined with phase-specific lethality of the toxic drug. It is likely, however, that daunorubicin provided partial protection from cytarabine-related cytotoxicity through its effect on the DNA synthesis rate.

Vascular relaxing activity and stability studies of 10,10-difluoro-13,14-dehydroprostacyclin

10,10-Difluoro-13,14-dehydroprostacyclin was compared with natural prostacyclin (prostaglandin I2, PGI2) for vascular relaxing activity in vitro on helical strips of small canine mesenteric arteries (outside diameter < 1 mm) and bovine coronary arteries (outside diameter 1.5-2.5 mm) partially contracted with prostaglanding F2 alpha as well as in vivo in pentobarbital-anesthetized dogs. The difluoro analog was 3- to 4-fold more active than PGI2 in causing relaxation of both types of strips and appeared at least equipotent to PGI2 in its blood pressure lowering effect in dogs. When incubated with Krebs' bicarbonate solution (pH 7.4) at 37 degrees C, the biological half-life of the difluoro analog was about 24 hr compared to the 10- to 15-min half-life of PGI2 under similar conditions. However, when administered intravenously to dogs, the hemodynamic effects of the difluoro analog were of the same duration as those of PGI2.

Inhibition of platelet aggregation and elevation of cyclic-AMP levels in platelets by 13,14-dehydro PGI2 methyl ester

13,14-Dehydro PGI2 (dh-PGI2) and 13,14-dehydro PGI2 methyl ester (dh-PGI2-Me) inhibited platelet aggregation and release of [14C]-serotonin and ADP induced by collagen, ADP, arachidonic acid and PGG2. The inhibitory dose (ID50) ofg dh-PGI2-Me on platelet aggregation was 3 x 10(-9)M when induced with collagen, 2 x 10(-8) M with ADP, 5 x 10(-9) M with arachidonic acid and 1 x 10(-8)M with PGG2. The effects of dh-PGI2 and dh-POGI2-Me on platelet aggregation appear to be mediated by cyclic AMP, since both agents were potent to stimulate platelet cyclic AMP formation. In this respect dh-PGI2-Me was more effective than dh-PGI2 and PGE1. The actions of dh-PGI2-Me on platelet aggregation reported in this study suggest that is posseses similar biological properties as natural PGI2. Since dh-PGI2-Me is considerably more stable at physiological pH than PGI2 (Fried, J. and Barton, J. (1977) Proc. Natl. Acad. Sci. USA, 74, 2199-2203) this PGI2 analog might be useful as an anti-thrombotic drug.

Multi-user system for analysis of data from flow cytometry

A new program is described for the analysis of DNA histograms from flow cytometry. The fundamental model representing the cell population is similar to one described previously. It assumes the population is grouped into compartments, each consisting of cells having approximately the same DNA content. After staining the cells with an appropriate fluorochrome, the fluorescence distribution of cells within each compartment is assumed to be Gaussian. In the present algorithm, the parameters of the model can either be computed directly by the program from the data, or can be specified as input by the user. When synchronous cell populations lacking distinct G1 and G2/M phases are analyzed, the parameter values must first be obtained using an appropriate control. Percentages of cells in the various compartments are computed using a gradient search method described by Bevington.

Comparison of substrate specificities of the human placental NAD- and NADP-linked 15-hydroxyprostaglandin dehydrogenases

A study of the relative activity of the purified placental NAD- and NADP-linked 15-hydroxyprostaglandin dehydrogenases with various prostaglandins and thromboxane B2 (TxB2) suggests that most, if not all, oxidation in the placenta of the 15-hydroxyl group of prostaglandins of the A, E, and F series as well as PGI2 (prostacyclin) and 6-keto PGF1 alpha is catalyzed by the NAD-linked enzyme. Prostaglandin B1 is an excellent substrate for the NADP-linked enzyme. Despite the conformational similarities between PGB1 and PGI2, the latter molecule is a poor substrate for the NADP-linked enzyme. Thromboxane B2 is not oxidized by the NAD-linked enzyme and is oxidized slowly by the NADP-linked enzyme.

Isolated Candida parapsilosis arthritis in a heroin addict

A case of isolated Candida parapsilosis arthritis involving the shoulder of a heroin addict is described. Amphotericin B successfully eradicated the infection after failure of flucytosine. Optimal therapy for this condition has not been determined.

Vascular smooth muscle activity of 7-oxa-13-prostynoic acid

The effects of 7-oxa-13-prostynoic acid (7-OPA), alone and as an antagonist of PGE2 and PGF2alpha, were investigaed in isolated rabbit aortic and canine renal arterial (diameter approximentaly 0.5 mm) strips. 7-OPA caused contractions in both preparations; threshold concentrations were 3- to 10-fold higher than the PGs and maximum contraction was 50-60%. In concentrations of 10(-5) M, 7-OPA inhibited contractions by PGF2alpha and PGE2. The same concentration of 7-OPA did not inhibit norepinephrine-induced contractions. These data indicate that 7-OPA is a partial agonist of PG receptors and produces its antagonism of PGE2 and PGF2alpha by that mechanism.