Elimination of oral food challenge reaction by injection of food extracts. A double-blind evaluation

Twenty subjects underwent a double-blind evaluation by analyzing six variables to determine if subcutaneous injection of the food extract neutralizing dose would protect subjects from reactions. Twelve subjects had four of the six variables neutralized 60% of the time following the food antigen neutralizing dose. The placebo trials neutralized four of six variables 15% of the time. The sign/symptom results show statistical significance favoring food extract neutralization over placebo. The remaining eight subjects had at least two of the six variables neutralized by the food extract up to 85% of the time. It appears that the phenomenon of subcutaneous food neutralization can be scientifically endorsed for clinical use in the treatment of food reactions.

Conditions influencing human sperm capacitation and penetration of zona-free hamster ova

The ability of human spermatozoa to penetrate zona-free hamster ova was examined following low-temperature capacitation (4 degrees C) in TES-Tris (TEST)-yolk buffer for periods of up to 66 hours. Results obtained from 66 individuals demonstrated that the number of penetrations per ova were increased by an average of 2.5-fold when spermatozoa were capacitated for 42 hours, as compared with 18 hours. Furthermore sperm with extremely poor penetration rates after 18-hour capacitation was often improved by longer capacitation periods. Patients from our infertility clinic with less than 20 X 10(6) spermatozoa/ml of ejaculate had significantly lower penetration rates when compared with patients and donors with greater than 20 X 10(6) spermatozoa/ml (P less than or equal to 0.001). The observed effects of TEST-yolk buffer appear to be related to its ability to preserve sperm motility over prolonged periods, during which increased capacitation of the total sperm population is achieved.

Synthesis of lactosaminoglycan-containing glycoproteins by vascular endothelial cells

Human vascular endothelial cells synthesize lactosaminoglycan-type glycoproteins which are found both associated with cells and secreted into the culture medium. Pronase-derived glycopeptides prepared from [3H]glucosamine-labeled glycoproteins were found to contain about 10% of the labeled products as a large size (Mr greater than 5000) 3H-labeled glycopeptide. Digestion of these 3H-labeled glycopeptides with endo-beta-galactosidase resulted in the release of smaller size saccharides, which were characterized as having the structure sialic acid----Gal----GlcNAc----Gal. Treatment of [3H]glucosamine-labeled cells with melittin caused 3H-labeled glycoconjugates to be released from the cells. Separation of released glycoproteins from proteoglycans by DEAE-cellulose chromatography indicated that melittin had released 25% of the total 3H-labeled glycoproteins from the cell and 3% of the 3H-labeled proteoglycans. The 3H-labeled glycoproteins were digested with Pronase and the resulting 3H-labeled glycopeptides were fractionated on Sephadex G-50. The large size fraction (Mr greater than 5000) now comprised about 30% of these released 3H-labeled glycopeptides. These high molecular weight 3H-labeled glycopeptides were degraded with endo-beta-galactosidase but not with testicular hyaluronidase. Analysis of the released 3H-labeled glycoproteins indicated a preferential release of glycoproteins of 70-90 kDa enriched in lactosaminoglycan-type oligosaccharides.

Immunologic function of endothelial cells: guinea pig aortic endothelial cells support mitogen-induced T lymphocyte activation, but do not function as antigen-presenting cells

The possibility that vascular endothelial cells (EC), like macrophages (M phi), can function as accessory cells necessary for mitogen- and antigen-induced T cell activation was examined. EC were enzymatically detached from the luminal surfaces of guinea pig aortas and then propagated in culture. Lymph node T lymphocytes were rigorously depleted of adherent cells, such that they completely lost the capacity to respond to mitogenic stimulation with phytohemagglutinin or concanavalin A. In this system, EC restored mitogen-induced T cell DNA synthesis as effectively as did M phi. This effect could not be explained by a facilitation of residual accessory cell activity within the responding T cell population, because EC restored mitogen responsiveness to T cells that had been treated with anti-Ia antibody and complement. Support of mitogen responsiveness could not be accounted for by secreted products of M phi or EC in the absence of intact accessory cells. In addition to the capacity to serve as fully sufficient accessory cells for the induction of mitogen-stimulated T cell proliferation, EC exerted a number of modulatory influences on T lymphocyte responses in cultures supported by M phi. When such cultures were supplemented with small numbers of EC, responses were dramatically augmented; larger numbers of EC resulted in marked suppression. At least part of these immunomodulatory effects could be accounted for by the activity of secreted products of EC. EC did not express detectable Ia antigens assayed either by indirect immunofluorescence, with the use of the fluorescence-activated cell sorter, or by complement-mediated cytotoxicity. Moreover, treating the EC population with anti-Ia antibody and complement had no effect on its capacity to support mitogen-induced T cell DNA synthesis. As would be expected from the lack of Ia antigen expression, EC were incapable of presenting antigen to primed T cells. They did, however, carry enough antigen into the cultures such that effective antigen presentation could occur when the cultures were supplemented with M phi that were syngeneic but not allogeneic to the responding T cells. Moreover, EC were capable of dramatically augmenting antigen-specific responses stimulated by antigen-pulsed M phi. There was no genetic restriction for this EC-mediated augmentation of antigen responsiveness. These results indicate that EC are capable of functioning as completely sufficient accessory cells for mitogen-induced T cell DNA synthesis and, in addition, are able to modulate ongoing M phi-supported T lymphocyte responses in both a positive and negative manner.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunologic function of endothelial cells: guinea pig aortic endothelial cells support mitogen-induced T lymphocyte activation, but do not function as antigen-presenting cells

The possibility that vascular endothelial cells (EC), like macrophages (M phi), can function as accessory cells necessary for mitogen- and antigen-induced T cell activation was examined. EC were enzymatically detached from the luminal surfaces of guinea pig aortas and then propagated in culture. Lymph node T lymphocytes were rigorously depleted of adherent cells, such that they completely lost the capacity to respond to mitogenic stimulation with phytohemagglutinin or concanavalin A. In this system, EC restored mitogen-induced T cell DNA synthesis as effectively as did M phi. This effect could not be explained by a facilitation of residual accessory cell activity within the responding T cell population, because EC restored mitogen responsiveness to T cells that had been treated with anti-Ia antibody and complement. Support of mitogen responsiveness could not be accounted for by secreted products of M phi or EC in the absence of intact accessory cells. In addition to the capacity to serve as fully sufficient accessory cells for the induction of mitogen-stimulated T cell proliferation, EC exerted a number of modulatory influences on T lymphocyte responses in cultures supported by M phi. When such cultures were supplemented with small numbers of EC, responses were dramatically augmented; larger numbers of EC resulted in marked suppression. At least part of these immunomodulatory effects could be accounted for by the activity of secreted products of EC. EC did not express detectable Ia antigens assayed either by indirect immunofluorescence, with the use of the fluorescence-activated cell sorter, or by complement-mediated cytotoxicity. Moreover, treating the EC population with anti-Ia antibody and complement had no effect on its capacity to support mitogen-induced T cell DNA synthesis. As would be expected from the lack of Ia antigen expression, EC were incapable of presenting antigen to primed T cells. They did, however, carry enough antigen into the cultures such that effective antigen presentation could occur when the cultures were supplemented with M phi that were syngeneic but not allogeneic to the responding T cells. Moreover, EC were capable of dramatically augmenting antigen-specific responses stimulated by antigen-pulsed M phi. There was no genetic restriction for this EC-mediated augmentation of antigen responsiveness. These results indicate that EC are capable of functioning as completely sufficient accessory cells for mitogen-induced T cell DNA synthesis and, in addition, are able to modulate ongoing M phi-supported T lymphocyte responses in both a positive and negative manner.(ABSTRACT TRUNCATED AT 400 WORDS)

Some effects of trichloroethylene on mouse lungs and livers

Repeated administration of trichloroethylene (TCE) to mice by either i.p. injection or by inhalation increased the activity of hepatic microsomal NADPH cytochrome-c reductase. The NADPH cytochrome c reductase activity in microsomes isolated from lungs of animals treated with TCE by inhalation was decreased relative to controls (untreated animals). TCE inhalation was associated with pathologic changes in lungs, but not in livers of the treated animals. The duration of exposure is probably an important factor however, since animals exposed for only 1 hr per day exhibited neither pathologic changes in the lungs nor an alteration of enzyme activity. These findings indicate that inhalation of TCE, without prior treatment with inducers, can enhance activity of the hepatic mixed function oxidase system. The reduced activity of the pulmonary mixed function oxidase system in animals that inhaled TCE may reflect injury to the lungs.

Steroid sulfatase activity in human lung tissue and in endothelial pulmonary cells in culture

The conversion of tritium-labeled estrone sulfate to [3H]estrone was evaluated in human lung tissue in vitro. Under standardized conditions, the rate of hydrolysis of [3H] estrone sulfate to [3H]estrone was linear with time of incubation up to 4 h and with wet tissue weight up to 400 mg/ml. The apparent Km of sulfatase for estrone sulfate was 9 microM, and the maximum velocity was 1.4 nmol substrate hydrolyzed/100 mg lung . h. The lung tissue also metabolized the primary metabolite of [3H]estrone sulfate, [3H]estrone, to 17 beta-[3H]estradiol. The hydrolysis of [3H]dehydroisoandrosterone sulfate to [3H]dehydroisoandrosterone by human lung tissue was also measured. Sulfatase activity with this substrate was linear as a function of wet tissue weight up to 800 mg/ml. The apparent Km of sulfatase for dehydroisoandrosterone sulfate was 7 microM, and the maximum velocity was 1.0 nmol substrate hydrolyzed/100 mg lung . h. The highest specific activity of lung sulfatase for [3H]dehydroisoandrosterone sulfate was found in a microsomal fraction of lung homogenate. The primary metabolite, [3H]dehydroisoandrosterone, was metabolized further by lung tissue to [3H]androstenedione and [3H]5-androstene-3 beta, 17 beta-diol. Although isolated segments of human pulmonary arteries also metabolized both [3H] estrone sulfate and [3H]dehydroisoandrosterone sulfate, cultures of pulmonary arterial endothelial cells lacked sulfatase activity. The cell(s) source of sulfatase activity in human lung tissue and isolated arteries has not yet been identified. Our findings suggest that the metabolism of sulfated steroids by the lung should be considered in evaluating homeostasis.

Metabolism of dehydroisoandrosterone and androstenedione in human pulmonary endothelial cells in culture

The capacity of endothelial cells from pulmonary arteries and veins to convert dehydroisoandrosterone (3 beta-hydroxy-5-androsten-17-one) and androstenedione to potent, biologically active steroids was investigated. The metabolites of [3H]dehydroisoandrosterone produced in pulmonary artery endothelial cells were androstenedione and 5-androstene-3 beta, 17 beta-diol. The metabolites isolated from incubation of pulmonary arterial cells with [3H]androstenedione were testosterone, 5 alpha-androstane-3,17-dione, 5 alpha-dihydrotestosterone (17 beta-hydroxy-5 alpha-androstan-3-one), isoandrosterone (3 beta-hydroxy-5 alpha-androstan-17-one), and androsterone. The products of [3H]androstenedione metabolism in human pulmonary venous cells were the same as those formed in arterial cells, and in addition, 5 alpha-androstane-3 alpha,17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol were formed. The rates of metabolite formation from [3H]androstenedione in pulmonary arterial and venous endothelial cells were linear with incubation time up to 3 h. These findings suggest that the pulmonary endothelium is an important site for the metabolism of dehydroisoandrosterone and androstenedione in the human lung. Endothelial cells produce the same metabolites as human lung tissue, with the exception of hydroxylated steroids.

Microbiological analysis of rock cod (Sebastes spp.) stored under elevated carbon dioxide atmospheres

The numbers and types of microorganisms on fresh rock cod fillets and fillets stored in air or in a modified atmosphere (MA; 80% CO(2), 20% air) at 4 degrees C were compared. Samples were analyzed after 0, 7, 14, and 21 days of storage. The isolation plates were incubated aerobically, anaerobically, or under MA at 4, 20, or 35 degrees C. After 7 days of storage in air, the fillets were obviously spoiled and had a 3- to 4-log cycle increase in microbial counts. Plate counts increased more slowly on MA-stored fillets. After 21 days, the counts on the latter had increased only 2 log cycles, and the fillets did not seem spoiled. The microbial flora changed greatly during MA storage. Only Lactobacillus spp. (70%) and an Aeromonas sp.-like isolate (30%) were found on plates incubated aerobically at 4 and 20 degrees C, and only Lactobacillus spp. was found on plates incubated aerobically and anaerobically at 35 and at 20 degrees C under MA. Isolation plates incubated at 20 degrees C in air gave the highest counts in the shortest incubation time and the greatest diversity of bacterial types recovered. No Vibrio parahaemolyticus, Staphylococcus aureus, or Clostridium botulinum type E were isolated from the fresh or MA-stored fillets.

Cytotoxicity of sera from patients with scleroderma. Effects on human endothelial cells and fibroblasts in culture

Sera from patients with progressive systemic sclerosis were compared with sera from normal individuals and from patients with other connective tissue diseases for cytotoxic effects on cultured human cells. More than 40% of the sera from patients with active progressive systemic sclerosis were cytotoxic by several criteria for pulmonary arterial or umbilical venous endothelial cells, foreskin fibroblasts, and neuroblastoma cells. Cytotoxic sera caused morphologic changes, uptake of trypan blue dye, and a decrease in the incorporation of 3H-thymidine into DNA. In contrast, only 4 sera from normal individuals or patients with other rheumatic diseases affected cell morphology, staining, or uptake of 3H-thymidine. Partial characterization of the cytotoxic factor indicated that it is sensitive to proteolysis by trypsin. The molecular weight of the factor was estimated to be similar to that of albumin.

Sulfated glycoproteins secreted by human vascular endothelial cells

Endothelial cells incorporate 35SO4 into a class of glycoproteins which are released from the cell layer into the culture medium. The incorporated 35SO4 was localized on intact oligosaccharide chains which were released from the protein either chemically by hydrazinolysis or enzymatically by a peptide: N-glycosidase activity; thus these 35S-oligosaccharides are presumably N-glycosidically linked to protein. These 35S-oligosaccharides were also isolated and analyzed as labeled glycopeptides and found to contain the terminal trisaccharide sequence sialic acid leads to galactose leads to N-acetylglucosamine. After removal of these carbohydrate residues, the remainder of this 35S-glycopeptide was susceptible to alpha-mannosidase digestion yielding a smaller 35 S-glycopeptide containing GlcNAc35SO4. Monensin (10(-8) M), a monovalent cation ionophore, inhibited the sulfation (greater than 80%) and synthesis (greater than 60%) of endothelial cell-sulfated proteoglycans which were released into the culture medium. However, neither the synthesis nor sulfation of cell-released 35S-glycoproteins was affected at similar monensin concentrations. Higher concentrations of monensin (greater 5 X 10(-8) M) inhibited the incorporation of both [3H]glucosamine and 35SO4 into cell-released glycoproteins.U

Stimulation of prostaglandin formation by vasoactive mediators in cultured human endothelial cells

Human endothelial cells in culture synthesize prostaglandins and release these products into the culture medium. The major products of arachidonic acid metabolism were identified by high pressure liquid chromatography or thin layer chromatography, and release of prostaglandins was measured by radioimmunoassays. Addition of histamine or bradykinin enhanced release of prostaglandins in both arterial and venous endothelial cells. Other vasoactive compounds including angiotensin II, vasopressin, substance P, epinephrine, norepinephrine, or isoproterenol were ineffective. Release of prostaglandins by histamine was concentration-related, and involved H1 receptors, as determined by addition of histamine antagonists. Incubation of endothelial cells with 14C-arachidonic acid resulted in a time-dependent uptake into cell lipids, where most of the radioactivity was incorporated into phosphatidyl choline and neutral lipids. Endothelial cells released 14C-arachidonic acid as well as 14C-prostaglandins in response to either histamine or bradykinin. The enhanced release of 14C-prostaglandins was inhibited by either indomethacin or mepacrine, but 14C-arachidonic acid release was inhibited only by mepacrine. We conclude that the vasoactive compounds, histamine and bradykinin, stimulate formation of prostaglandins in endothelial cells by the release of arachidonic acid from phospholipids of the cell membrane.

Chemicals in marine and coastal environments: the need for toxicological information

The tremendous increase in the number and amount of chemicals produced and transported in past years has resulted in increasing problems with accidental spills and uncontrolled waste sites involving these chemicals. The United States government has accordingly developed a mechanism for responding to such incidents. As part of that mechanism, the Hazardous Materials Response Project serves to coordinate scientific activities and facilitate in the gathering of scientific information needed for response to chemical spill or waste site emergencies involving coastal waters. Inevitably, much information of a toxicological nature is required to adequately evaluate potential hazards and appropriate responses. The Hazardous Materials Response Project is also able to provide a framework for significant progress in scientific understanding because it can bring together and encourage collaboration among experts in the various disciplines which are relevant to the environmental toxicological problems encountered.

Uptake and release of 14C-morphine by pulmonary endothelium and cultured pulmonary endothelial cells

1. Isolated perfused rabbit lungs and cultured pulmonary endothelial cells take up radiolabeled [14C]morphine in proportion to the amount of labeled drug in the medium. 2. The accumulated label is readily released from the isolated lungs by perfusion with unlabeled morphine or naloxone, but not by perfusion with Krebs-Ringer solution, sucrose or thiopental. 3. Thiourea also enhances efflux of radioactivity, suggesting that the release is not related to interaction with specific opiate receptors. 4. Uptake of [14C]morphine by cultured rabbit or human endothelial cells is unaffected by morphine or naloxone, and the release of radioactivity is not enhanced by these agents. 5. None of the drugs used caused pulmonary edema in the isolated lung preparation, and they did not cause the release of lactic dehydrogenase from cultured endothelial cells. 6. It is concluded that morphine can be taken up by pulmonary endothelium, but it is probably not bound to specific receptors, and it does not injure the endothelial cells.

Anti-platelet activity of beta-adrenergic antagonists: inhibition of thromboxane synthesis and platelet aggregation in patients receiving long-term propranolol treatment

Treatment of hypertensive patients with dl-propranolol (640 mg/day) significantly inhibited thromboxane synthesis by their platelets and platelet aggregation induced by thrombin or arachidonic acid. The effects were dose-related and were also caused by the stereoisomer, d-propranolol (640 mg/day), which has very little beta-blocking activity. These findings suggest that the cardioprotective effects of propranolol may be due partly to this anti-platelet activity, to a reduction in thromboxane-induced coronary-artery vasoconstriction, or to both. d-Propranolol treatment may be particularly useful, since this isomer provides similar benefits without causing pronounced beta-adrenergic blockade.

[Mycobacteria in the digestive tract of pink Flamingos (Phoenicopterus ruber roseus, Pallas)]

Cloacal swabs were taken from 37 young wild Greater Flamingos (Phoenicopterus ruber roseus, Pallas) in Camargue (South of France). Neither pathogenic strain, nor environmental one were found. The absence of the latter could be attributed to the high NaCl levels of the ecosystems.

Human endothelial cell-lymphocyte interaction. Endothelial cells function as accessory cells necessary for mitogen-induced human T lymphocyte activation in vitro

Mitogen-stimulated human T cell activation is absolutely dependent on the participation of a nonresponding accessory cell. In populations of human peripheral blood mononuclear cells, monocytes function as the requisite accessory cells. The possibility that cultured endothelial cells (EC) might also function as accessory cells was studied by examining the potential of endothelial cells to restore mitogen responsiveness to monocyte-depleted human T cells. Highly purified T cells were prepared by isolating cells rosetting with sheep erythrocytes and removing monocyte contamination by glass adherence and nylon wool column passage. When cultured at low cell density, T cells failed to respond to stimulation with various mitogenic lectins, whereas co-culture with monocytes restored responsiveness. Similarly, EC obtained from umbilical vein, pulmonary artery, and ovarian vein restored the capacity of T cells to respond to mitogens. Mitogen-stimulated T cell activation required viable endothelial cells. Moreover, effective endothelial T cell cooperation appeared to involve the establishment of cell-to-cell contact between EC and responding T cells. Accessory cell function was not a nonspecific property of all tissue culture cells as evidenced by the finding that human foreskin fibroblasts, lung fibroblasts, and HeLa cells were unable to restore responsiveness to monocyte-depleted T cells. These observations indicate that endothelial cells can support the induction of mitogen-induced T cell activation and suggest that cells lining blood vessels may play an active role in the initiation of immune responses in vivo.

Prolylcarboxypeptidase (angiotensinase C) in human lung and cultured cells

The activity of prolylcarboxypeptidase (PCP), or angiotensinase C, was measured in lung tissues, leukocytes, and cultured human cells using Cbz-Pro-[14C]Ala as a substrate. A lysosomal fraction of homogenized rat or human lung contained most of the PCP activity in that tissue. Polymorphonuclear neutrophils, macrophages, and lymphocytes isolated from human blood had PCP activity. Fibroblasts cultured from human tissues had the highest activity (0.56-1.15 mumol/h per 10(6) cells), more than endothelial cells cultured from human pulmonary arteries. PCP of cultured human fibroblasts was similar to the human renal enzyme because it was resistant to moderate heating and was not inhibited by p-chloromercuriphenyl sulfonic acid. These properties and the substrate specificity distinguish PCP from cathepsin A, which is also in fibroblasts. Antibody to human renal PCP reacted with fibroblast PCP in immunofluorescence, indicating common antigenic determinants. Hydrocortisone changed PCP activity in fibroblasts in parallel with changes in beta-glucuronidase activity and cell-protein concentration; the activity was depressed at low concentration of the hormone. PCP activity was also found in synovial fluid from arthritic joints and in fibroblasts from the synovium. That PCP is found in both inflammatory exudates and in cells that appear at sites of inflammation indicates that, in addition to inactivating angiotensins, this enzyme may have a role in inflammation.

Sulfated glycoproteins and extracellular matrix of cultured human pulmonary endothelial cells

Endothelial cells derived from human pulmonary arteries incorporate (3H)-glucosamine and 35SO4 into glycosaminoglycans and into the carbohydrate side chains of glycoproteins. These 3H/35S-carbohydrate chains were isolated from cells and culture medium after Pronase digestion. The 3H/35S-glycosaminoglycans were separated from the 3H/35S glycopeptides by chromatography on Sephadex G-50. The distribution of cellular glycosaminoglycans and glycopeptides indicated that 30-60% of the cellular 35S-glycopeptides may be associated with the matrix components that are synthesized by the cell and attached to a plastic substratum. Human pulmonary arterial endothelial cells were grown on collagen or on a matrix derived from vascular smooth muscle cells in order to investigate how smooth muscle cell extracellular matrix components may regulate the synthesis of endothelial cell glycoconjugates. Endothelial cells grown on plastic release various proportions of the glycoconjugates they synthesize into the culture medium. However, these same cells, when grown on substratum composed of extracellular matrix materials, synthesized altered proportions of cell-associated glycosaminoglycans and reduced the levels of total glycosaminoglycans they released into the culture medium. Thus the growth of endothelial cells on a matrix of smooth muscle cell components indicates that the glycosaminoglycan materials released into the culture medium by cells grown on a plastic substratum may not be an accurate reflection of the levels or composition of extracellular matrix materials made by endothelial cells in vivo.

Biotin and the sudden infant death syndrome

A diet which is marginally deficient in the vitamin biotin may cause sudden unexpected death of young broiler chickens when they are exposed to stress. Chickens affected with this disorder have low levels of biotin in their livers. In conditions of biotin insufficiency, we postulate that a similar disorder, triggered by mild stress, may occur in the human infant. We have now used a radiochemical technique to measure the biotin content of 204 livers obtained from infants at autopsy. The levels of biotin in the livers of infants who had died of sudden infant death syndrom (SIDS; cot death) were significantly lower than those in livers of infants of similar age, who had died of explicable causes. These findings support an association of biotin with SIDS.

Human pulmonary endothelial cells in culture. Activities of cells from arteries and cells from veins

Endothelial cells were cultured from various different human vessels, including aortas, pulmonary, ovarian, and umbilical arteries, and pulmonary, ovarian, and umbilical veins. The cultured cells were identified as endothelial cells by the presence of Factor VIII antigen and antiotensin I converting enzyme (kininase II). They retained these markers for at least five passages in culture, and some cells had them for seven passages or more. Endothelial cells from the various vessels were compared with respect to their ability to metabolize angiotensins I and II and bradykinin. Cells from arteries had three to five times the angiotensin I converting enzyme activity as cells from veins. The activity of angiotensinase A (aspartyl aminopeptidase) had a similar distribution, and cells from arteries were consistently more active than cells from veins. Cultures of endothelial cells from pulmonary and umbilical vessels formed prostacyclin in response to mechanical stimulation. Media from cell monolayers that were subjected to a change of medium and gentle agitation inhibited aggregation of human platelets. This inhibitory activity was generated within 2-5 min, and it was not formed by cells that were treated with indomethacin or tranylcypromine. Addition of prostaglandin (PG)H(2) to indomethacin-treated cells restored the ability to form the inhibitor, but cells treated with tranylcypromine were not responsive to PGH(2). In experiments where [(14)C]arachidonic acid was added to the cells before stimulation, the major metabolite identified by thin-layer chromatography was 6-keto PGF(1alpha). Thus, it appears that pulmonary endothelial cells, as well as umbilical cord cells, can form prostacyclin. In experiments comparing the ability of arterial and venous cells to form prostacyclin, arterial cells were more active than venous cells. These studies of cells from various human vessels suggest that the vascular origin of cultured endothelial cells determines how they metabolize vasoactive peptides and form prostacyclin.

Dietary polyunsaturated fats and malignant melanoma

The consumption of polyunsaturated fat of a group of patients with malignant melanoma was compared to that of various groups of control subjects to determine whether such dietary fats predispose to the development of malignant melanoma. The results are tabulated with reference to various associated factors, and a statistical assessment of their significance is presented. The writers were unable to agree on the interpretation of the results, and present two opposing views on whether the ingestion of polyunsaturated fat is associated with the incidence of malignant melanoma.

Kinins and angiotensins. Angiotensin I converting enzyme (kininase II) in endothelial cells cultured from human pulmonary arteries and veins

Human pulmonary endothelial cells were used to study the metabolism of angiotensin I and bradykinin by angiotensin I converting enzyme (kininase II; ACE). The endothelial cells cultured from pulmonary arteries and veins differed with respect to their enzyme activity and their surface structure, as viewed with scanning electron microscopy. Cells from adult pulmonary arteries had greater ACE activity than cells from either adult pulmonary veins or fetal pulmonary arteries. In addition, cells from adult pulmonary arteries exhibited more prominent surface projections than cells from veins or fetal pulmonary arteries. A brief exposure to trypsin decreased the ACE activity in cells from arteries but not in cells from veins. Possible the differences in ACE activity between these cells are related to their surface structures.

Growth-promoting actions of extracts from mouse submaxillary glands on human endothelial cells in culture

Extracts of submaxillary glands from two different strains of inbred mice were mitogenic for human endothelial cells in culture. The mitogenic activity of extracts from glands of males of the SWR/J and C57BL/10J strains were equivalent, and the growth stimulating effect was unrelated to renin or esteroproteolytic activity. Mitogenic activity in extracts from SWR/J females was less than that from males, and extracts from C57BL/10J females were inactive. The polypeptide growth factors, epidermal (EGF) and fibroblast (FGF) growth factors, also stimulated replication of endothelial cells. Cells from either umbilical arteries or veins responded to submaxillary extracts, EGF, or FGF with a similar increase in cell number, increase in protein and enhanced uptake of 3H-thymidine. The proliferative response was associated with decreased activity of angiotensin I converting enzyme which is localized on the endothelial surface. Nerve growth factor (NGF) was not mitogenic for endothelial cells. Extracts of submaxillary glands from male mice of either strain contained approximately 20 times more EGF than extracts from females, as determined by immunodiffusion. Mitogenic activity of the extracts was completely inhibited by antiserum to EGF, suggesting that the active component of these preparations is EGF.

Effects of life span feeding of ruminant-derived human diets to rats

A freeze-dried human diet, based on linoleic acid-enriched food stuffs derived from ruminants, was evaluated and compared with a similarly-prepared diet based on conventional ruminant-derived foodstuffs, using Porton rats in a whole-of-life study. A cereal-based stock diet was used for comparison. Serum biochemical and histopathological examinations were carried out at 0.25, 1.1 and 2.1 years of age and other rats were left until they died of natural causes. Although some diet-specific biochemical differences were noted, triglyceride and cholesterol levels showed changes which were more age-specific than diet-specific. Longevity did not seem to be influenced by quantity or quality of dietary fat. The most common cause of death was a bronchopneumonia at about 2 years of age. Dietary fat also did not affect incidence of tumors. The most common tumor was a pituitary adenoma which occurred most often in females. Only minor causes of death were specific to diet with waxy intra-cardial plaques occurring in less than 5% of rats fed both of the high-fat diets and severe systemic hypertension occurring in rats fed the low-fat stock diet at the same frequency. No deleterious changes were noted that were unique to the linoleic acid-enriched diet.

Tumour incidence, growth, reproduction and longevity in female C3H mice fed polyunsaturated ruminant-derived foodstuffs

Earlier studies with the random-bred Quackenbush mouse strain showed that human-type diets based on linoleic acid-enriched foodstuffs derived from ruminants fed protected polyunsaturated oils have no detrimental effects on growth, reproduction or longevity. Tumour incidence and time of onset of tumour development have now been studied in the inbred, tumour-prone mouse strain C3H, in addition to growth, reproduction and longevity. Mice were fed a polyunsaturated human diet, a conventional human diet, or mouse cubes. The results with C3H mice tended to confirm those with Quackenbush strain mice-growth rates and reproductive productivities were very similar in the two groups eating human diets. Mice on the conventional human diet tended to survive better to about 60 weeks of age than mice on the polyunsaturated diet or the cube diet, after which the mortality rates of the mice on the three diets were similar. The degree of unsaturation of the dietary fat had no significant effect on the incidence of tumours. The tumour incidence was about 40% which, taken in conjunction with the average age of onset (about 80 weeks), suggested that the NIV virus rather than the MMTV virus was responsible. It would appear that the high-fat human diets had no effect on the incidence of mammary tumours caused by this virus.

Uptake of 125I-labelled C3a by cultured human endothelial cells

The interactions of C3a anaphylatoxin with vascular endothelium were studied in vitro using human endothelial cells in culture and 125I-labelled human C3a. Cultured endothelial cells took up 125I-C3a in a time- and concentration-dependent manner and inactivated it. Uptake was not associated with binding to specific receptors since the amount of radioactivity accumulated by the cells was not influenced by treatment with excess unlabelled peptide, metabolic inhibitors or by low temperature. Further, we observed that uptake was not saturated during 90 min of incubation or within the concentration range of C3a tested (10(-9)--10(-6) M). C3a was taken up more rapidly than other labelled, less basic compounds, including Tyr5-bradykinin, lysozyme and albumin. Examination of the cells by autoradiographic electron microscopy revealed labelled material within the cell cysoplasm but not within specific intracellular structures, such as vesicles or vacuoles. C3a was partially inactivated after incubation with endothelial cells for 15 min, but some spasmogenic activity was retained even after 90 min incubation. Since the peptide is readily inactivated by the cells, the radioactivity in the cytoplasm may be inactive C3a and possibly C3a fragments. The combination of uptake and inactivation of C3a by endothelial cells may be an effective means of removing the peptide from circulation.

Growth, reproductive productivity and longevity of mice fed polyunsaturated ruminant-derived foodstuffs

The effects on the well-being of mice of feeding linoleic acid-enriched foodstuffs derived from ruminants receiving protected polyunsaturated oil were determined. Growth, reproductive productivity and longevity were compared in mice fed freeze-dried human diets containing either these products or the corresponding conventional ruminant-derived foods. A laboratory mouse pellet diet was used as a standard for the comparison. Growth rates and life spans were found to be similar in all three groups. Although the reproductive productivity of the mice on the polyunsaturated diet was never significantly different from that of mice on the conventional human diet, productivities of both groups on human diets were usually significantly below those of mice eating pellets. By the third generation of the second reproduction study, productivities of both these groups of mice had returned to the same level as those of mice eating pellets. Possible reasons for the depression in reproductive productivity in mice on the human diets are discussed. It was concluded that the polyunsaturated human diet neither impaired nor improved the lives of the animals eating the diet relative to the lives of animals eating the conventional human diet.

Growth, Reproductive Productivity and Longevity of Mice Fed Polyunsaturated Ruminant-Derived Foodstuffs

The effects on the well-being of mice of feeding linoleic acid-enriched foodstuffs derived from ruminants receiving protected polyunsaturated oil were determined. Growth, reproductive productivity and longevity were compared in mice fed freeze-dried human diets containing either these products or the corresponding conventional ruminant-derived foods. A laboratory mouse pellet diet was used as a standard for the comparison.

Renal inactivation of substance P in the rat

The activity and distribution of substance P-catabolizing enzyme(s) were studied in the rat kidney. Kidney homogenates inactive substance P 5-20 times as fast as do homogenates of intestine, liver, lung, heart or brain. The catabolizing activity was highest in the cortex and decreased progressively down the papilla. Cortex of rat kidney was homogenized and fractions enriched in microsomal membrane, final supernatant, plasma membrane, endoplasmic reticulum, brush border and intact glomeruli were prepared. The identity and homogeneity of the preparations were determined by assaying marker enzymes and by morphological examination. Substance P was catabolized most rapidly by the microsomal and plasma-membrane-enriched fractions, and least rapidly by endoplasmic reticulum or final supernatant fractions. Purified brush border of proximal tubules inactivated substance P more than 10 times as fast as isolated glomeruli. Our experiments show that substance P is catabolized at a rate that is similar to the rates of inactivation of bradykinin and angiotensin II. Further, the distribution of substance P-catabolizing activity in various kidney fractions is similar to the distribution of kininase and angiotensinase activities previously reported.

The effects of inorganic ions situated at the enamel surface on the adsorption and activity of acid phosphatase

This study has demonstrated, first, that the affinity of the enamel surface for a biologically active protein-in this case, acid phosphatase-may be modified by first impregnating the mineral with particular inorganic ions. Second, enzymic activity is altered as a function of the inorganic ion incorporated into the enamel surface. Third, strong inhibition of acid phosphatase is demonstrated by ions expected to be released during the carious process which contradicts the postulation that phosphatases are actively hydrolyzing enamel matrix-bound phosphate during the carious attack. Fourth, these results suggest that by incorporating a particular ion into the enamel mineral, a surface with assigned properties may be created which offers some degree of control over subsequent adsorption of organic matter. Thus, it is apparent that by proper selection of inorganic ions and organic macromolecules, both structural properties and biological activities at the enamel-oral fluid interface may be predictably modified.

Metabolism of vasoactive peptides by human endothelial cells in culture. Angiotensin I converting enzyme (kininase II) and angiotensinase

Cultured endothelial cells provide a model for the study of interactions of vasoactive peptides with endothelium. Endothelial cell cultured from veins of human umbilical cords contain both angiotensin I converting enzyme (kininase II) and angiotensinase activities. Intact monolayers of cells can both activate angiotensin I and inactivate bradykinin when the peptides are added to culture flasks in protein-free medium. Intact suspended cells or lysed cells convert angiotensin I to angiotensin II, inactivate bradykinin, and hydrolyze hippuryldiglycine to hippuric acid and diglycine. These actions are inhibited by SQ 20881, the specific inhibitor of converting enzyme. The kininase activity of endothelial cells was partially inhibited by antibody to human lung converting enzyme. Endothelial cells also inactivate longer analogs of bradykinin, such as kallidin, methionyl-lysyl bradykinin, and bradykinin coupled covalently to 500,000 mol wt dextran. The endothelial cells retained converting enzyme activity through four successive subcultures, indicating that the enzyme is synthesized by the cells surface, and it is apparently a marker for endothelial cells, since cultured human fibroblasts, smooth muscle cells, and baby hamster kidney cells do not have it. Endothelial cells also contain an aminopheptidase which hydrolyzes both angiotensin II and the synthetic substrate, alpha-L-aspartyl beta-naphthylamide. The angiotensinase activity increased when the cells were lysed, which suggests that the enzyme is localized within the cells, Hydrolysis of both alpha-L-aspartyl beta-naphthylamide and angiotensin II was inhibited by omicron-phenanthroline, indicating that the enzyme is an A-tipe anigotensinase.

Fatty liver and kidney syndrome in chicks. II. Biochemical role of biotin

The role of biotin-dependent enzymes in the fatty liver and kidney syndrome of young chicks was studied. Under conditions of a marginal deficiency of dietary biotin, the level of biotin in the liver has differing effects on the activities of two biotin-dependent enzymes, pyruvate carboxylase and acetyl-CoA carboxylase. The activity of acetyl-CoA carboxylase is increased, but when the dietary deficiency of biotin produces biotin levels which are below 0-8 mug/g of liver, the activity of pyruvate carboxylase may be insufficient to completely metabolize pyruvate via gluconeogenesis. There is an increase in liver size and in the activities of enzymes involved in alternate pathways for the removal of pyruvate. Blood lactate accumulates and there is increased synthesis of fatty acids, and an accumulation of palmitoleic acid; these steps are accomplished by increased activities of at least the following enzymes: acetyl-CoA carboxylase, malate dehydrogenase (decarboxylating) (NADP+) and the desaturase enzyme. When the biotin level is below 0-35 mug/g of liver and the chick is subjected to a stress, physiological defence mechanisms of the chick may be inadequate to maintain homeostasis and they finally collapse, resulting in accumulation of triacylglycerol in the liver and blood; the chick is unable to maintain blood glucose levels and death occurs, often only a few hours after the imposition of the stress.

Fatty liver and kidney syndrome in chicks. I. Effect of biotin in diet

Fatty liver and kidney syndrome, a disorder of young chicks, was studied under laboratory conditions. Affected chicks had enlarged livers (hepatomegaly), an increased content of lipid in the liver, and an increased level of palmitoleic acid in the liver lipids. The disorder was observed mainly in chicks from young parent flocks, and was associated either with commerical diets which were subsequently found to be low in biotin, or with specially formulated low-biotin diets. A third factor, imposition of stress, was required to initiate the disorder. There was evidence of increased lipogenesis causing an increase of triacylglycerols in the liver lipids and an increased production of saturated fatty acids, particularly palmitic acid. Increased levels of palmitoleic acid resulted from an increased desaturation of palmitic acid. Under stress, affected chicks had low blood glucose levels, suggesting that gluconeogenesis was impaired. Since biotin-dependent enzymes are involved in both gluconeogenesis and lipogenesis, it would appear that the relevant enzymes respond differently to a deficiency of biotin.

Effects of protected cyclopropene fatty acids on the composition of ruminant milk fat

Unsaturated fatty acids can be protected from ruminal hydrogenation, and when fed to lactating ruminants, the constituent acids are incorporated into milk triacylglycerols. By this means, it has been possible to reduce the melting point of milk triglycerides and to make softer butter fat. This report shows that, by feeding small amounts of protected cyclopropene fatty acids, one is also able to make harder butter fat. Sterculia foetida seed oil, a rich source of cyclopropene fatty acids, was emulsified with casein and spray dried to yield a free flowing dry powder. When this material was treated with formaldehyde and fed to lactating goats(ca. 1 g cyclopropene fatty acids per day), there were substantial increases in the proportions of stearic acid and decreases in the proportions of oleic acid in milk fat. Similar results were obtained when the formaldehyde-treated supplements were fed to lactating cows (ca. 3 g cyclopropene fatty acids per day). The effect was considerably less apparent when the S. foetida seed oil-casein supplement was not treated with formaldehyde, suggesting that cyclopropene fatty acids are hydrogenated in the rumen as are other unsaturated fatty acids. The effect of feeding protected cyclopropene fatty acids on the stearic:oleic ratio in milk fat is probably due to cyclopropene-mediated inhibition of the mammary desaturase enzymes.

Gas-liquid chromatography of ethyl ester artifacts formed during the preparation of fatty acid methyl esters

Ethanol is typically used as a stabilizer in chloroform. Failure to remove this ethanol from the chloroform used in the extraction of lipids leads subsequently to the formation of ethyl ester artifacts during the preparation of methyl esters by a commonly employed transesterification procedure. Depending on the conditions and phases used during gas-liquid chromatography, the ethyl esters may be resolved from the corresponding methyl esters. The resulting chromatograms contain extraneous peaks and may be incorrectly identified.

Autoxidation in milk rich in linoleic acid. II. Modification of the initiation system and control of oxidation

Factors contributing to the initiation of lipid oxidation in cow's and mare's milk containing high levels of polyunsaturated fatty acids were studied. Addition of H2O2 just after milking, in slight excess of the stoichiometric amounts required to destroy ascorbic acid, delayed the development of oxidized flavours in cow's milk high in linoleic acid. Hydrogen peroxide treatment followed by the addition of alpha-or gamma-tocopherols prevented lipid oxidation in cow's milk even when 0.1 mg Cu/l milk was added. When used separately in the presence of Cu these treatments were ineffective as was butylated hydroxyanisole treatment. The lipid and ascorbic acid in mare's milk were remarkably stable to oxidation. Addition of 0.05 or 0.1 mg Cu/l, ethylenediamine tetraacetic acid, neocuproine, or H2O2 had very little effect on the loss of ascorbic acid and lipid oxidation in mare's milk.

Observations on calcium-induced stability of salivary proteins in a lipid-extraction system

The system described for investigating the effects of small ions on macromolecules of saliva may be applied to other solutions and is amenable to manipulation in order to obtain more specific information. Studies using aqueous solutions of saliva fractions previously separated by gel filtration are being conducted with C/M solutions containing various bivalent cation chloride salts. Preliminary results from these current studies have demonstrated that when the proteins are stabilized they vary as a function of the cation used.

Release of histamine from rat mast cells by the complement peptides C3a and C5a

Suspensions of rat mast cells were used to study the histamine-releasing actions of anaphylatoxins C3A and C5a in vitro. The peptides, derived from human or porcine complement proteins C3 and C5, were less potent than 48/80 but more potent than bradykinin in stimulating release of histamine from mast cells. The pattern of release resembled that of the anaphylactic release action, e.g. release was limited to less than 30 per cent of the cell histamine, the reaction was calcium-dependent and was potentiated by phosphatidyl serine. When C3a and C5a were added together to mast cell suspensions, the amount of histamine released was additive. Similarly, release by either peptide combined with bradykinin was additive. Histamine-releasing activity (as well as smooth muscle-stimulating activity) was abolished when the peptides were treated with pancreatic carboxy-peptidase B. Active or inactive peptides were bound by mast cells and addition of active C3a in combination with the inactive, des-arginine derivative, C3ai, resulted in partial inhibition of histamine release.

The uptake of a substituted acridone by rat mast cells in relationship to histamine release: a possible indicator of exocytosis-induced expansion of the plasma membrane

A substituted acridone, 10-(2-dimethylaminopropyl)-9-acridone HCl (M-129), was taken up by isolated rat peritoneal and pleural mast cells in direct relationship to the degree of selective histamine release induced by compound 48/80. Other selective releasing agents, i.e., polymyxin B and anti-rat mast cell serum, also augmented uptake of M-129. Augmented uptake of M-129 was inhibited by measures that inhibited selective histamine release, i.e., cold, brief heating of the mast cells, N-ethylmaleimide and ninhydrin. 48/80 did not agument uptake of M-129 in rat erythrocytes or in rat serous fluid cells from which mast cells had been removed. M-129 taken up by mast cells was readily removed by two to three washes. Augmented uptake induced by 48/80 was specific for M-129 and acridone itself. Related compounds, i.e., a quaternary acridone derivative [10-(2-triethylaminoethyl)-9-acridone iodide] (M-231), acridine and acridan did not show augmented uptake. There was no relationship between heptane-water partition coefficients and uptake. It is postulated, based on estimates of cell membrane area, that M-129 is loosely bound to plasma membrane and that the augmented uptake associated with selective histamine release from rat mast cells is due to expanded plasma membrane that results from irreversible or slowly reversible exocytosis.