Depth Cues of Disparity and Relative Size Added to Necker Cube

A stereogram was prepared in which one of the alternating facets of the Necker cube was drawn with uncrossed disparity and a reduced size relative to the opposite facet. During a 2-min. stereoscopic viewing period, the disparity cue and reduced-size cue did not affect the number of reversals in depth; however, the depth cues led to the disparate and smaller facet being perceived as more distant for a longer duration than the other facet.

Effect of nordihydroguaiaretic acid on cultured rat and human glioma cell proliferation

When cultured malignant cells derived from rat gliomas (C6 and 9L) and human gliomas (A-172 and T98G) were treated for 4 hours with 1 to 80 microns nordihydroguaiaretic acid (NDGA) or 5,8,11,14-eicosatetraynoic acid (ETYA), a dose-dependent inhibition of deoxyribonucleic acid (DNA) synthesis occurred. In a series of three experiments for each cell line, 40 microM NDGA suppressed 3H-thymidine incorporation in the rat and human glioma lines to an average of less than 3.1% and 5.6% of control uptake (counts per minute), respectively. Incubation with a higher concentration of ETYA (80 microM) resulted in inhibition of rat and human DNA synthesis to less than 53% and 62% of control levels, respectively. This inhibition was not associated with any loss of cell viability, as judged by trypan blue exclusion studies. Prolonged incubation (for 72 hours) of the rat and human glioma cells with NDGA markedly decreased cell proliferation with no loss of cell viability. The inhibition of human glioma cell division by NDGA was rapidly reversible after incubation for 24 hours and at least partially reversible after incubation for 96 hours. It is concluded that the inhibitors of eicosanoid biosynthesis, NDGA and (to a lesser extent) ETYA, reduce in vitro cell proliferation in two glioma lines from both the rat and human. Since neither indomethacin nor acetylsalicylic acid altered DNA synthesis in these cell lines, this implicates the lipoxygenase products of arachidonic acid metabolism as important positive modulators in glioma cell division. These findings warrant further study in an in vivo system.

Inhibition of U937 eicosanoid and DNA synthesis by 5,8,11,14-eicosatetraynoic acid, an inhibitor of arachidonic acid metabolism and its partial reversal by leukotriene C4

When replicating U937 cells were incubated with up to 80 microM concentrations of the in vitro inhibitor of eicosanoid biosynthesis, 5,8,11,14-eicosatetraynoic acid (ETYA), DNA synthesis measured by labeling with [3H]thymidine was inhibited in a concentration-dependent manner. No reduction in cellular viability occurred, as judged by exclusion of trypan blue, unaltered release of 51Cr-labeled proteins, and the reversibility of inhibition after incubation for 72 h with ETYA. Neither indomethacin nor acetylsalicylic acid, inhibitors of cyclooxygenase, altered DNA synthesis in control or ETYA-inhibited cells, excluding participation of the products of this enzyme in the inhibition of DNA synthesis. Incubation of inhibited cells with extracts prepared from log-phase media partially reversed the inhibition of DNA synthesis. Addition of leukotriene B4 or D4 at 10(-7) to 10(-8) M did not reverse ETYA-induced inhibition of DNA synthesis, nor did the addition of a series of long chain fatty acids, including arachidonic acid. However, leukotriene C4 at 10(-7) M partially reversed the inhibition of DNA synthesis. Extracts of media from log-phase cells were shown by high-pressure liquid chromatography to contain leukotriene C4, and synthesis of this compound was inhibited by ETYA, as judged by measurement of UV absorbance and radioactivity. Additional inhibitors of eicosanoid metabolism including nordihydroguaiaretic acid and esculetin also suppressed DNA synthesis in U937, K562, and prostate PC3 cells, without altered cellular viability; the effect is not limited to lymphohematopoietic cells or to a single inhibitor of arachidonic acid metabolism. Suppression of U937 DNA and eicosanoid synthesis by ETYA and the partial reversal of DNA synthesis by leukotriene C4 suggest that in these cells eicosanoids may modulate DNA synthesis. Other possible consequences of incubating cells with ETYA including creation of arachidonic acid-deficient membranes, and even incorporation of the agent into membrane phospholipids, may also contribute to the reversible inhibition of DNA synthesis.

5,8,11,14-eicosatetraynoic acid-induced differentiation of U937 cells

U937 cells, transformed human monocyte/macrophage precursors, incubated with 5,8,11,14 eicosatetraynoic acid (ETYA), a competitive in vitro and in vivo inhibitor of arachidonic acid, develop properties consistent with a form of cellular differentiation. In order to define the extent of this differentiation and decide whether a monocyte or macrophage-like cell developed, control cells and cells cultured for three days with 40 microns ETYA were examined by transmission electron microscopy. Control cells were characterized by oval nuclei, a high nuclear to cytoplasmic ratio, a cytoplasm with a relative paucity of mitochondria, vesicles and vacuoles, and a Golgi apparatus that was not extensively developed. Ribosomes and putative ribosome-like granules were frequently "grouped" in the cytoplasm, rather than as single granules or in association with the endoplasmic reticulum. The plasma membrane included a discrete region of fimbriated structures that were distinct from pseudopodia. Such structures frequently are expressed in embryonic and transformed cells and may be associated with motility, metastases, with immunologic reactions or with endocytosis. After culture with 40 microns ETYA for three or more days, a morphology consistent with that of immature monocytes developed. These characteristics included lobulated nuclei, a reversal of the nuclear to cytoplasmic ratio, an increased complexity and development of the cytoplasmic components and the disappearance of the fimbriated plasma membrane structures. In addition, "grouped" ribosomes were less evident.(ABSTRACT TRUNCATED AT 250 WORDS)

Requirements for histoplasmin presentation by accessory cells to a Histoplasma capsulatum-reactive T-cell line

We examined the pathways involved in presentation of native histoplasmin by adherent splenocytes (as a source of accessory cells) to JC1, a Histoplasma capsulatum-reactive murine T-cell line that is CD4+. JC1 did not respond to accessory cells that had been fixed with paraformaldehyde and then exposed to histoplasmin but did proliferate to antigen-pulsed cells that were subsequently fixed. Accessory cells that were coincubated with histoplasmin and sodium azide or 2-deoxy-D-glucose failed to induce proliferation of JC1. Moreover, accessory cells exposed to the lysosomotropic agents, chloroquine and ammonium chloride, were unable to present antigen. Monensin also inhibited presentation of histoplasmin if added to accessory cells concomitant with antigen. In contrast, accessory cells that had been pulsed with antigen for 2 hr and then exposed to each inhibitor for 2 hr stimulated proliferation of JC1. The antigen-presenting capacity of accessory cells that had been pulsed with histoplasmin for 2 hr was diminished considerably by subsequent treatment with phospholipase A2. Additional studies demonstrated that cerulenin, which depresses posttranslational lipid modification of proteins, abolished presentation of histoplasmin. The reactivity of JC1 was sharply reduced by anti-L3T4 (CD4) or by anti-I-Ab monoclonal antibody. The results not only indicate that presentation of histoplasmin requires active metabolic events within accessory cells, they also delineate the pathways involved in handling this antigen.

A phase I clinical trial of recombinant interleukin-2 by periodic 24-hour intravenous infusions

Recombinant interleukin-2 (rIL-2) (NSC# 600664; Hoffmann-La Roche, Inc., Nutley, NJ) was studied in a phase I clinical trial in 33 patients with advanced, measureable cancer of the colon or malignant melanoma, Eastern Cooperative Oncology Group (ECOG) performance status O-1, and no prior chemotherapy or radiotherapy. The goal of the study was to identify a dose and schedule of IL-2 to generate maximal immune modulation with tolerable toxicity. Such a regimen might allow the addition of other treatment modalities and/or prolonged treatment duration in later trials. Each patient received IL-2 as a continuous 24-hour infusion once weekly for 4 weeks and then twice weekly for 4 weeks. Five treatment groups received from 10(3) U/m2 to 3 x 10(7) U/m2 per 24-hour infusion. The maximal tolerated dose was 3 x 10(7) U/m2/d twice weekly. Patients treated twice weekly at 1 x 10(7) and 3 x 10(7) U/m2/d had immune modulation in terms of lymphocytosis, eosinophilia, increased natural killer (NK) activity, and elevated numbers of peripheral blood mononuclear cells expressing CD16, OKT10/Leu-17, and Leu-19 surface markers. Endogenous generation of peripheral blood lymphokine-activated killer (LAK) activity was demonstrated by lysis of NK-resistant Daudi targets, in patients treated at 3 x 10(7) U/m2/d. Biochemical and hematological abnormalities were moderate and reversible. Clinical toxicity included hypotension, myalgia, arthralgia, stomatitis, fever, fatigue, nausea, headache, chills, diarrhea, and oliguria at high doses. Cardiovascular toxicity was tolerable for most patients and reversed after IL-2 was stopped. Two of six melanoma patients at 3 x 10(7) U/m2/d achieved partial responses by the end of the eighth week. This IL-2 schedule appears to produce potentially clinically useful immune enhancement with tolerable toxicity.

A simple chromatographic procedure for the detection of cyclized archaebacterial glycerol-bisdiphytanyl-glycerol tetraether core lipids

Archaebacterial glycerol-bisdiphytanyl-glycerol tetraether core lipids containing from one to eight cyclopentane rings could be resolved from each other and from the parent uncyclized C40, C40 lipid by TLC. The core lipids of examples from the genera Methanobacterium, Methanobrevibacter, Methanogenium and Methanoplanus did not contain cyclized forms of glycerol-bisdiphytanyl-glycerol tetraethers, whereas the core lipids of Methanosarcina barkeri contained glycerol-bisdiphytanyl-glycerol tetraethers with from one to three cyclopentane rings in each C40 isopranoid chain.

Monocyte functional studies in asymptomatic, human immunodeficiency disease virus (HIV)-infected individuals

Various aspects of monocyte-associated function were evaluated in the peripheral blood mononuclear cells of male homosexuals who were infected with the human immunodeficiency disease virus (HIV). The functional assessments included indomethacin-sensitive regulation of blastogenesis and lymphokine-activated killer (LAK)-cell induction, chemiluminescent responses of mononuclear leukocytes to opsonized zymosan, and the expression of HLA-DR antigen on CD-14-positive monocytes. The results obtained demonstrate that each of these functions is abnormal in asymptomatic individuals who have HIV core antigen (p24) in their circulation. These results suggest that monocyte abnormalities which could contribute to immune dysfunction in HIV-infected patients can be detected early during the course of HIV infection and are associated with the expression of serum HIV antigen.

Synthesis of hepatic protein during pregnancy in the rat

The accumulation of hepatic protein during pregnancy in the rat could be the result of a decrease in rate of degradation, an increase in rate of synthesis or both. The purpose of the study was to determine relative rates of synthesis of hepatic protein for pregnant and nonpregnant rats. Pregnant and nonpregnant Sprague-Dawley rats were fed a 20% casein, purified diet from the first day of gestation. On d 19 of gestation the rats were killed. Livers were weighed and assayed for RNA. Relative synthesis rates of hepatic protein were assessed by homologous in vitro cell-free translation. RNA per liver and per g liver and incorporation of labeled leucine into protein per liver and per unit of RNA were greater for the pregnant rats than the nonpregnant rats. In conclusion, accumulation of hepatic protein during pregnancy is at least partially the result of an increase in rate of synthesis.

Characterization of antigenic determinants in histoplasmin that stimulate Histoplasma capsulatum-reactive T cells in vitro

Although antigen-reactive T lymphocytes play a central role in the host response to Histoplasma capsulatum, little is known of the nature of Histoplasma antigens recognized by these cells in vitro. Employing a murine T-cell line and two clones that are reactive with histoplasmin, we examined whether activation of T cells by histoplasmin required the presence of carbohydrate or protein moieties. The approach taken was to modify carbohydrate or protein molecules in histoplasmin by chemical or enzymatic digestion or by lectin adsorption. In parallel, antigen was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis to correlate alterations in functional activity with changes in the electrophoretic appearance of histoplasmin. Treatment of histoplasmin with periodate (0.1 M, 0.05 M, and 0.01 M) or with the endoglycosidases N-glycanase and endoglycosidase H sharply diminished the capacity of histoplasmin to trigger responses by T cells. Reactivity of T cells to histoplasmin that had been adsorbed with lectins binding mannose, glucose, or galactose was reduced by greater than 70%; conversely, the responses by T cells to antigen that had been adsorbed with lectins specific for fucose, N-acetylgalactosamine, or N-acetylglucosamine ranged from 82 to 91% of that to control antigen. Proliferative responses by T cells to histoplasmin that had been digested with chymotrypsin, protease, or trypsin were 2 to 43% of control values. The electrophoretic appearance of histoplasmin was modified by some but not all of the treatments. Partially purified H and M antigens triggered proliferation of T cells. Thus, both carbohydrates and proteins must be present to induce optimal responses by T cells. A portion of the carbohydrates is N linked to proteins, and alpha-D-mannose (or alpha-D-glucose) and beta-D-galactose are the sugar ligands of carbohydrate-containing antigens.

Paleoradiologic evaluation of the Egyptian royal mummies

We examined radiographs of 12 Egyptian royal mummies obtained by two of the authors (W.R. and J.E.H.) and never before published. These radiographs demonstrate findings not previously described in Egyptian mummies, including congenital lunate-triquetral fusion and destructive skeletal lesions not explainable on the basis of vandalism by tomb robbers. Antemortem fractures, degenerative joint disease, and arterial vascular calcification were also seen. In 11 of the 12 cases, there was chondrocalcinosis of intervertebral discs or menisci, probably an artifact of embalming. Visceral packing and skeletal deformity due to wrapping were observed, as well. Radiology provides important paleopathologic and archeologic information for the accurate, comprehensive study of Egyptian mummies.

Labelling of lipids and phospholipids with [3H]arachidonic acid and the biosynthesis of eicosanoids in U937 cells differentiated by phorbol ester

Phorbol esters induce morphologic and biochemical differentiation in U937 cells, a monocyte/macrophage-like line derived from a human histiocytic lymphoma. We are interested in the phorbol ester-stimulated release of arachidonic acid from cellular membranes and the subsequent synthesis of eicosanoids, as it may prove to correlate with the induced cellular differentiation. Undifferentiated log-phase U937 cells released little recently incorporated [3H]arachidonic acid, but phorbol 12-myristate 13-acetate increased its apparent rate of release to that of cells differentiated by exposure to phorbol myristate acetate for 3 days. Exposure of washed differentiated cells immediately prelabelled with [3H]arachidonic acid to additional phorbol myristate acetate did not augment the release of [3H]arachidonic acid. The basal release of nonradioactive fatty acids from differentiated cells was 5-10 times that of undifferentiated cells, and phorbol myristate acetate increased their release from both types of cell 2- to 3-fold. Differentiated cells immediately prelabelled with [3H]arachidonic acid exhibited greater incorporation into phosphatidylinositol and phosphatidylcholine, and contained more radioactive free arachidonic acid, compared with undifferentiated cells. Undifferentiated cells contained more radioactivity in phosphatidylserine, phosphatidylethanolamine and neutral lipids. Phorbol myristate acetate caused differentiated cells to release [3H]arachidonic acid from phosphatidylinositol, phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine, but release from neutral lipids was reduced, and the content of [3H]arachidonic acid increased. In undifferentiated cells incubated with phorbol myristate acetate, radioactivity associated with phosphatidylserine, phosphatidylethanolamine and neutral lipid was reduced and [3H]arachidonic acid was unchanged. Synthesis of cyclooxygenase products exceeded that of lipoxygenase products in both differentiated and undifferentiated cells. Phorbol myristate acetate increased the synthesis of both types of product, cyclooxygenase-dependent more than lipoxygenase-dependent, especially in differentiated cells. The biological significance of these changes in lipid metabolism that accompany phorbol myristate acetate-induced differentiation are yet to be established.

In vivo effects of recombinant IL-2. I. Isolation of circulating Leu-19+ lymphokine-activated killer effector cells from cancer patients receiving recombinant IL-2

This study was designed to isolate and phenotypically characterize lymphokine-activated killer (LAK) cells generated in vivo during administration of high dose rIL-2 to cancer patients. The development of circulating LAK effector cells in these patients was demonstrated by the ability of fresh PBL to exhibit lytic activity against the NK-resistant Daudi cell line and fresh tumor cells without prior in vitro culture with rIL-2. Kinetic studies demonstrated that circulating LAK effector cells are detectable 4 to 6 wk after the initiation of rIL-2 therapy. Cells isolated by FACS revealed that circulating LAK cells are Leu-19+, Leu-17+ but CD5-. We have previously reported that circulating Leu-19+ cells are heterogeneous with regard to the expression of CD16 and CD8. Since sorting of cells expressing Leu-19 and either low quantities of CD8 or CD16 resulted in cytolytic activity in both the positive and negative fractions, these latter two markers do not identify subpopulations of Leu-19+ cells with or without LAK cytolytic activity. Although all LAK cells generated in vivo were Leu-19+, we generated LAK cells from the Leu-19- subpopulation after in vitro culture with rIL-2, suggesting that at least some of in vitro generated LAK cells are derived from Leu-19- precursor cells. These LAK cells did not, however, express the Leu-19 surface marker. Based on the functional data reported in this paper, we conclude that circulating LAK effector cells are a phenotypically heterogeneous population that express surface Ag in association with NK cells and not T lymphocytes.

In vivo effects of recombinant IL-2. I. Isolation of circulating Leu-19+ lymphokine-activated killer effector cells from cancer patients receiving recombinant IL-2

This study was designed to isolate and phenotypically characterize lymphokine-activated killer (LAK) cells generated in vivo during administration of high dose rIL-2 to cancer patients. The development of circulating LAK effector cells in these patients was demonstrated by the ability of fresh PBL to exhibit lytic activity against the NK-resistant Daudi cell line and fresh tumor cells without prior in vitro culture with rIL-2. Kinetic studies demonstrated that circulating LAK effector cells are detectable 4 to 6 wk after the initiation of rIL-2 therapy. Cells isolated by FACS revealed that circulating LAK cells are Leu-19+, Leu-17+ but CD5-. We have previously reported that circulating Leu-19+ cells are heterogeneous with regard to the expression of CD16 and CD8. Since sorting of cells expressing Leu-19 and either low quantities of CD8 or CD16 resulted in cytolytic activity in both the positive and negative fractions, these latter two markers do not identify subpopulations of Leu-19+ cells with or without LAK cytolytic activity. Although all LAK cells generated in vivo were Leu-19+, we generated LAK cells from the Leu-19- subpopulation after in vitro culture with rIL-2, suggesting that at least some of in vitro generated LAK cells are derived from Leu-19- precursor cells. These LAK cells did not, however, express the Leu-19 surface marker. Based on the functional data reported in this paper, we conclude that circulating LAK effector cells are a phenotypically heterogeneous population that express surface Ag in association with NK cells and not T lymphocytes.

Modification of the effects of cytotoxic chemotherapy on the immune responses of cancer patients with a nonsteroidal, antiinflammatory drug, piroxicam. A pilot study of the Eastern Cooperative Oncology Group

We have attempted to modify the manner in which chemotherapy influences immune function in lung cancer patients by adding the nonsteroidal, antiinflammatory drug (NSAID) piroxicam to a cytotoxic drug treatment regimen. Eighteen previously untreated patients with lung cancer received cytotoxic chemotherapy with mitomycin-C (10 mg/m2), vinblastine (6 mg/m2), and cis-platinum (40 mg/m2) (MVP) on day 1 of a 21-day treatment cycle; 12/18 patients also received piroxicam (20 mg/day) beginning 10 days prior to MVP and persisting throughout the 21-day treatment cycle. In vitro tests included (a) phytohemagglutinin (PHA) responsiveness in the presence of indomethacin or interleukin-2 (IL-2), (b) natural killer cell (NK) function, and (c) PHA-induced IL-2 synthesis. In the 6 patients treated with MVP alone, depressed PHA reactivity was found pretherapy, which was augmented by indomethacin, but not by IL-2; this was associated with impaired production of IL-2. By days 7-14, PHA reactivity, IL-2 responsiveness, and IL-2 production rebounded to normal. By days 14-21, PHA reactivity had declined once again in association with increased indomethacin-regulation and impaired IL-2 responsiveness and production. In the 12 patients who received MVP plus piroxicam, PHA and IL-2 assays improved by days 7-14 and indomethacin-regulation was normal; moreover, this improvement persisted throughout the 21-day treatment cycle. Immunological rebound persisted through as many as 3 consecutive 21-day MVP plus piroxicam treatment cycles in patients who were continuously monitored. In contrast to these results, piroxicam did not alter the way chemotherapy affected NK function. These results demonstrate that the immunomodulatory effects of cytotoxic chemotherapy can be modified or ameliorated by adding an NSAID to the cytotoxic drug treatment regimen; for certain functions, such as mitogen-stimulated blastogenesis or IL-2 production, sustained immunological rebound without immunosuppression can be achieved by this maneuver.

High-dose lymphoblastoid interferon in advanced renal cell carcinoma: an Eastern Cooperative Oncology Group Study

This report describes a phase II Eastern Cooperative Oncology Group (ECOG) study of high-dose lymphoblastoid interferon (IFN alpha-n1) in 39 patients with measurable, advanced renal cell carcinoma. The original treatment plan was 30 X 10(6) units/m2 (30 mU) of IFN alpha-n1 im daily X 10 days; treatments were repeated every 21 days. This dose and schedule proved intolerable, with none of seven patients able to complete greater than 10 days of therapy because of fever, lassitude, hepatic dysfunction, and myelosuppression. Patients were subsequently treated with the following regimen: 3 mU/m2 on Day 1; 5 mU/m2 on Day 2; 10 mU/m2 on Day 3; and 20 mU/m2 on Days 4-10. Thirty-three new patients received this regimen and two patients received this schedule after having received 30 mU/m2. Using this second regimen, 30% of the patients were able to complete two cycles of treatment without dose reduction or interruption. Five patients (13%) had partial response (ECOG criteria) of measurable tumor. Median time to response was 140 days. Responses were documented in lung metastases in four patients and in a pelvic soft tissue mass in the fifth. Response rates and survival times are similar to those seen in prior ECOG phase II trials in advanced renal cell carcinoma. Eight of 39 patients are still alive greater than 2 years after beginning therapy. Only two of these patients had had an objective response, however. Such prolonged survival is more frequent than has been seen in previous ECOG studies. The relative contribution of patient selection and interferon therapy to this survival is uncertain.

Clinical evaluation of efficacy, pharmacokinetics, and safety of teicoplanin for serious gram-positive infections

Nineteen patients hospitalized for serious gram-positive infections were treated with teicoplanin, a new glycopeptide antibiotic. A variety of infections were treated, including endocarditis, septic thrombophlebitis, osteomyelitis, pyogenic arthritis, and soft tissue infection. Of 13 infections that could be evaluated in 12 patients, there were 8 clinical cures, 2 improvements, 1 recurrence, and 2 failures. Of the eight patients with Staphylococcus aureus bacteremia, seven were clinically cured or improved with teicoplanin therapy. Of the nine patients in whom the bacteriological response to treatment could be fully evaluated, six were cured; there was recurrence of infection in one, and treatment failed in two patients. In vitro testing showed the 13 bacterial isolates (9 S. aureus, 3 S. epidermidis, and 1 group B streptococcus) to be uniformly susceptible to teicoplanin, with MICs ranging from 0.12 to 0.5 microgram/ml. Every isolate was more susceptible in vitro to teicoplanin than to vancomycin. Three of the staphylococcal isolates were resistant to methicillin. Pharmacokinetic studies demonstrated that after an initial drug-accumulation period, a single daily dose adequately maintained the teicoplanin concentrations in serum within therapeutic ranges. Teicoplanin also penetrated well into synovial fluid. The drug was well tolerated by either intravenous or intramuscular administration. The most significant adverse reaction was an urticarial rash which required discontinuation of therapy in one patient; a second patient experienced a modest decrease in high-frequency auditory threshold. Asymptomatic eosinophilia and mild elevation of serum transaminases were noted as well. The results of this study suggest that teicoplanin is a safe and effective new agent for treatment of serious infections caused by gram-positive organisms.

dam methylation in the archaebacteria

The DNA of certain species of halophilic and methanogenic archaebacteria is dam methylated, as shown by restriction endonuclease sensitivities. The Dam+ phenotype appears to be confined to particular taxonomic groupings defined by DNA:rRNA hybridization or 16S RNA oligonucleotide cataloguing.

Modulation of lymphocyte responsiveness to phytohemagglutinin by micromolecular fibrinogen degradation products

The ability of fibrinogen degradation products (FDP) to influence the regulatory function of adherent cells from peripheral blood mononuclear cells (PBMC) was evaluated. FDP were prepared by digestion of fibrin clots with plasmin. These FDP were incubated overnight with glass-adherent cells following which these treated and untreated cells were cocultivated with fresh autologous responder PBMC in the presence of the T-cell mitogen, phytohemagglutinin (PHA). Lipid metabolism of FDP-treated monocytes was evaluated in cells that had been prelabeled with [3H]arachidonic acid (AA) prior to their overnight incubation with FDP; supernatants were analyzed for conversion of AA to cyclooxygenase and lipoxygenase products by thin-layer chromatography. Treatment of glass-adherent cells with the FDP digests converted these monocytes into suppressor cells. The suppression exerted by these cells in the PHA assay was dose dependent. The suppression exerted by FDP-pretreated monocytes was reversed by treating the PHA-stimulated cocultures with indomethacin and was associated with increased cyclooxygenase activity. These studies demonstrated that FDP can alter T-cell immune function through the induction of monocyte suppressor cells; the means by which that occurs is associated with stimulation of lipid metabolism and secretion of eicosanoids with immunoregulatory capacity.

Properties of in vitro recombinant derivatives of pJV1, a multi-copy plasmid from Streptomyces phaeochromogenes

The 10.8 kb plasmid pJV1, isolated from Streptomyces phaeochromogenes, has a high copy number (about 150) and a broad host range among Streptomyces spp. Several pJV1 derivatives carrying the thiostrepton resistance gene (tsr) of S. azureus were made. One derivative, pWOR191, was shown to promote its own transfer and to mobilize chromosomal markers in S. lividans. Another derivative, pWOR109, was non-transmissible. Deletion in vitro of a segment of pWOR109 gave pWOR120 (5.6 kb), which has single BamHI and Bg/II sites shown to be capable of accepting 'foreign' DNA such as a previously cloned S. antibioticus DNA fragment encoding tyrosinase, giving vectors (pWOR125, pWOR126) with properties resembling the well-established multicopy vector pIJ702. Shuttle vectors capable of functioning in both S. lividans and Escherichia coli were also constructed. The region of pJV1 essential for replication and maintenance was localized to a 2.5 kb segment. Stable maintenance of pWOR109 and pWOR120 was observed in the presence of derivatives of pIJ101, the progenitor of pIJ702.