Inhibition of MCP-1 and MIP-2 transcription and translation by mimosine in muscle tissue infected with the parasite Trichinella spiralis.

Mimosine is a non-toxic plant aminoacid which is an effective inhibitor of DNA replication by acting at the S-phase. In this study we infected mice with T. spiralis, a nematode parasite, and studied the inflammatory response through the determination of MIP-2, a C-X-C chemokine and MCP-1, a C-C chemokine in the inflamed area around the parasitic cyst. The animals were infected and their diaphragms were tested for inflammatory response. MCP-1 and MIP-2 was tested after 1, 10, 20, 30, and 40 days post inoculation, before and after mimosine treatment. The inflammatory index was calculated by counting the white blood cells around the nematode cysts, while expression of MIP-2 and MCP-1 was calculated by ELISA method and transcription by Northern blot and RT-PCR. Here we found that mimosine strongly inhibited the inflammatory index in the diaphragmatic tissue at 10, 20, 30 and 40 days post-treatment. In these experiments, mimosine had no effect on the number of cysts produced. In addition, we found that MCP-1 transcription and translation was completely inhibited by mimosine, while MIP-2 transcription and translation was partially inhibited at 30 and 40 days; yet it was totally inhibited after 10 and 20 days in encysted diaphragm tissue infected by T. spiralis. Our studies suggest that mimosine has an inhibitory effect through the inhibition of cytoplasmatic serine hydroxymethyltransferase altering the cell cycle of white blood cells. This study suggests for the first time the premise that mimosine acts as an anti-inflammatory compound.

Vitamin B6-deficient diet plus 4-deoxypyridoxine (4-DPD) reduces the inflammatory response induced by T. spiralis in diaphragm, masseter and heart muscle tissue of mice.

Animals fed diets deficient in vitamin B6 develop microcytic anemia, alterations of growth, and other pathologies. 4-deoxypirydoxine is a potent antagonist of vitamin B6 coenzyme which depresses IL-1, TNF and IL-6 and has anti-inflammatory properties. The aim of this study was to show the anti-inflammatory effects of 4-DPD on chronic inflammation caused by the nematode parasite T. spiralis, specifically on the recruitment and the activation of inflammatory cells. Two groups of mice, 6 weeks of age, were used: one was maintained on a vitamin B6-deficient synthetic pellet diet for 15 days before injection of the nematode, and administered an intraperitoneal injection (i.p.) of 4-DPD (250 microg/mouse) for 15 days (the first, 5 days before infection), and the second group was maintained on a normal diet for the total duration of the experiment. These two groups were then injected with 150 larvae (L1-T7 spiralis) per os. Chronic inflammation was caused by infection of treated or untreated mice with T7 spiralis parasite. After 14 days post-infection all mice developed a chronic inflammatory response. Mice fed with a B6-deficient diet showed a significant decrease in the number of cysts found in the diaphragm when compared to mice treated with normal diet. In addition, in all mice treated with vitamin B6-deficient diet plus 4-DPD the average body weight was significantly lower, compared to the mice on normal diet in all weeks examined. Moreover, in sections of the diaphragm, masseter and myocardium muscles, the infiltration of inflammatory cells, such as macrophages, lymphocytes, and eosinophils were more intense in untreated mice compared to those fed a vitamin B6-deficient diet. These results show that BALB/c mice infected with T. spiralis and fed a vitamin B6-deficient diet plus the vitamin B6 antagonist, 4-DPD, prolong the time of invasion of the larvae in the muscle cells, influence the recruitment of inflammatory cells and the intensity of the inflammatory reaction compared to infected untreated mice (control).

IgG, IgG1 and IgM response in Trichinella spiralis-infected mice treated with 4-deoxypirydoxine or fed a Vitamin B6-deficient diet.

The aim of this study was to investigate the effect of pyridoxine (Vitamin B6) deficiency on the immunological response of BALB/c mice infected with the parasite T. spiralis. Specific anti-parasite IgM and IgG immunoglobulins were detected by ELISA method in the serum of treated animals at different periods for 60 days post infection. Vitamin B6-deficiency was induced in two separate groups of mice by either (1) maintaining the mice on a Vitamin B6-deficient synthetic pellet diet for 40 days before infection, or (2) by daily intraperitoneal injection of 8 x 10(5) M/100 microl of 4-Deoxypyridoxine (4-DPD), a potent antagonist of Vitamin B6 for 20 days prior to infection. These two groups of mice were then injected with 100 larvae (L1-T. spiralis) per os. Parasite burdens in the mice were observed by light microscopy. Cysts were present in the diaphragms of the mice after 60 days post-infection. Parasite specific IgG, as well as IgG1 levels were determined in the sera of infected mice fed a normal diet. These levels were found to be lower in the 4-DPD-treated mice compared to the untreated mice. The inhibition started from the 10th day and continued to the 60th day, and in the 4-DPD-treated group the inhibition initiated after 24 h to 60 days. IgM level also was depressed by 4-DPD, starting from 24 h after injection of the compound. In mice fed Vitamin B6-deficient diets the levels of IgG were lower than in mice fed normal diets. These results show that BALB/c mice infected with T. spiralis and fed either a Vitamin B6-deficient diet or a diet which included the Vitamin B6-antagonist, 4-DPD, both influence the course of IgG, IgG1 and IgM production.

Induction of monocyte chemotactic protein-1 (MCP-1) and TNF alpha by Trichinella spiralis in serum of mice in vivo.

MCP-1 is a small (8-10 KDa) protein and a prototype member of the CC chemokine beta subfamily, which plays a critical role in acute and chronic inflammation. Recent evidence suggests an important role for MCP- 1, MCP-2 and MCP-3 in a number of pathological states, including delayed type hypersensitivity conditions, parasitic infections and rheumatoid arthritis. Forty BALB-c mice were treated with the parasite Trichinella spiralis. After the infection the animals were sacrificed at different periods from the initial infection and MCP-1 and TNFalpha were quantified in the mouse serum. The level of MCP-1 in the serum of mice infected with 100 larvae increases from 27.5+/-7.0 pg/ml at day 23, to a maximum level of 31.5+/-5.0 pg/ml at day 33, then decreased to 14.6+/-2.0 pg/ml at day 47. When the mice were infected with 200 larvae of T. spiralis the maximum increase was 34.4+/-2.5 pg/ml found on day 23. From day 33 to day 47 MCP-1 levels were decreased. In addition, in infected mice levels of TNFalpha were detectable in the serum as early as day 1. The level of TNFalpha was maximum at day 35 (3812+/-224 pg/ml). Serum from non-infected mice contained no detectable levels of either MCP-1 or TNFalpha. However, even if MCP-1 seems to be implicated in Trichinellosis, its exact role and function in inflammatory parasitic diseases remains to be determined.

Massive infiltration of basophilic cells in inflamed tissue after injection of RANTES.

Regulated upon activation normal T expressed and secreted (RANTES) is a new inducible protein member of the human C-C branch of chemokines. RANTES is a potent monocyte and lymphocyte chemoattractant and is a mediator of inflammatory responses. In these studies we found that RANTES 10 ng/50 microl chemoattracts basophilic cells in a dose-dependent manner 4 h after an intradermal injection in rat skin sites, as revealed by optic microscopy. Moreover, in biopsy specimens from rat skin injection sites histamine release was significantly higher (P < 0.05) than in controls (PBS 50 microl) after 4 h from RANTES treatment. The presence of basophilic cells in rat skin injection sites after RANTES-treatment was also confirmed by electron microscopy studies. In addition, histidine decarboxylase (HDC) mRNA was increased in rat skin sites injected with RANTES compared to sites injected with PBS (controls). Our report describes additional biological activities for RANTES, suggesting that this human chemoattractant protein may play a fundamental role in histamine and HDC generation, along with basophilic cell recruitment.

Infra-red laser irradiation enhances interleukin-1 receptor antagonist, increases 3H-thymidine incorporation and the release of [3H]arachidonic acid in human monocytes.

The effect of infra-red laser irradiation has been experimented on various biological systems and particularly in human tissues, in vitro as well as in vivo. In order to examine the influence of laser irradiation on cells of the monocytic lineage we have irradiated human peripheral blood mononuclear cells with an infra-red laser at a wavelength of 904 nm, at 2000 Hz frequency and 15 mW for 2 min. Here, we report that laser irradiation for 2 min. at different preincubation times (T = 0 and T = 30 min) enhances LPS (10 micrograms/ml or PHA (10 micrograms/ml, suboptimal concentration)-stimulated monocytes by modifying cell proliferation, as judged by [3H] thymidine incorporation. IL-1 receptor antagonist (IL-1ra) along with an increased release of [3H] Arachidonic acid production, is also influenced by laser irradiated monocytes when treated for 2 min after 1 h incubation. IL-1RA production increased 4-5 fold after laser irradiation, while 3H-arachidonic acid incorporated from PMA-stimulated cells increased and the effect was significant at T = 0 and T = 30 min; while at T = 1 h the effect was negligible. These results may provide new information regarding the effect of laser irradiation on the immune system.

Pyridoxine deficiency: new approaches in immunosuppression and chemotherapy.

Pyridoxine deficiency leads to impairment of immune responses. It appears that the basic derangement is the decreased rate of production of one-carbon units necessary for the synthesis of nucleic acids. The key factor is a pyridoxine enzyme, serine hydroxymethyltransferase. This enzyme is very low in resting lymphocytes but increases significantly under the influence of antigenic or mitogenic stimuli, thus supplying the increased demand for nucleic acid synthesis during an immune response. Serine hydroxymethyltransferase activity is depressed by deoxypyridoxine, a potent antagonist of pyridoxal phosphate, and also by known immunosuppressive or antiproliferative agents. The combination of these agents is additive. Our results lead us to suggest the following medical applications: (a) combination of deoxypyridoxine with immunosuppressive or chemotherapeutic drugs may be effective in cases of immunosuppressive therapy or organ transplantation, (b) the development of special agents directed against the serine hydroxymethyltransferase apoprotein may prove to be a valuable medical tool, since this enzyme presents an excellent target for chemotherapy, (c) lymphocytes of individual patients could be used to design tailor-made specific immunosuppressive or chemotherapeutic treatment, and (d) the serine hydroxymethyltransferase activity of lymphocyte culture presents an excellent indicator for the evaluation of potency of immunosuppressive, chemotherapeutic or genotoxic compounds in a simple and rapid test.

Haemoglobin O Arab in the Pomak population of Thrace.

A 21 year old woman from Thrace with clinical and laboratory findings of mild hemolysis, was found to be homozygous for haemoglobin O Arab. Blood samples from 15 members of her family and from 42 inhabitants of her village were examined for the presence of Hb O Arab. A high incidence of this variant allele was also detected among the patient's family members as well as in other inhabitants of the village (p = 0.274 +/- 0.049). The possibility that Pomaks, a culturally unique tribe with controversial ethnic origin, may represent one of the original pools for the geographic distribution of the gene in the broader area of the Mediterranean basin is discussed.

Lipid peroxidation and antioxidant defense mechanisms in rat renal tissue after daunorubicin administration.

Redox cycling compounds such as daunorubicin have been assumed to be toxic because they stimulate reactive oxygen-mediated lipid peroxidation. Furthermore, both DT-diaphorase and glutathione (GSH) have been regarded as protective cellular compounds against daunorubicin cardiotoxicity, but their role in daunorubicin nephrotoxicity remains unclear. To investigate this issue, 10 adult Wistar rats were twice injected with a single dose of 20 mg/kg body weight daunorubicin into the tail vein; the interval between injections was 48 h. A control group of 10 rats were injected with normal saline. One day after the second injection, all the animals were sacrificed and their kidneys were analyzed for malondialdehyde (MDA) as an index of lipid peroxidation, DT-diaphorase activity, and GSH and glutathione disulphide (GSSG) content. A significant increase of MDA concentration (2.41 vs. 1.64 p < 0.001) and DT-diaphorase activity (0.2 vs. 0.12, p < 0.001) was found in the renal tissue of daunorubicin injected rats. In contrast, GSH and GSSG levels were decreased in those animals (566 vs. 1282, p < 0.001 and 115 vs 187, p < 0.01, respectively). The results of this study give evidence that a high dosage of daunorubicin induces lipid peroxidation in renal tissue of rats stimulating the activation of DT-diaphorase and the detoxificative depletion of GSH.

Human recombinant interleukin-1 beta induces thromboxane A2 release in polymorphonuclear leukocytes, macrophages and platelets: effect of IL-1 receptor antagonist.

Prostaglandins and thromboxanes (Txs) are produced by polymorphonuclears (PMNs) and macrophages (Mphis) in response to various stimuli. PMNs were separated from other human blood cells and Mphis were separated from rat peritoneal lavage. In this paper we show that human recombinant interleukin-1 (hrIL-1) can stimulate the release of thromboxane B2 (TxB2) by PMNs and Mphis. In addition, we have shown that aggregation of PMNs may occur when calcium ions (7 mM) and hrIL-1 (100 ng/ml) are added to the cell preparation, but not when Ca2+ alone, hrIL-1 alone, or first hrIL-1 then calcium are added to the cell preparation. The treatment of human platelets with hrIL-1 shows that after 15 min incubation TxB2 is released. In addition, we compared the aggregation of platelets caused by ADP with that caused by hrIL-1. Human recombinant IL-1 at a concentration of 100 ng/ml also causes little aggregation of platelets, in this case the aggregation is reversible. In conclusion, hrIL-1 beta stimulates TxB2 release in PMNs, Mphis and platelets and this effect increases with addition of Ca2+ ions. The mixture of hrIL-1 and Ca2+ causes little aggregation of PMNs. In monocyte suspensions, pretreated with human recombinant IL-1 receptor antagonist (IL-1ra) 500 ng/ml for 10 min and then treated with LPS or hrIL-1 beta 10 micrograms/ml, the release of TxB2 was partially inhibited. IL-1ra may play a significant role in the control of IL-1 and LPS induction in the release of TxB2.

Possible role of transferrin in exfoliation syndrome.

Protein concentration was measured in 30 exfoliation syndrome samples and 22 age matched controls. Exfoliation samples contained significantly more protein than controls. We also analyzed by SDS gel electrophoresis 32 aqueous samples, 12 with exfoliation syndrome and 20 age matched controls. A novel finding in all samples was a double band with 77 kDa and 78 kDa. These bands probably represent transferrin isoforms, with different carbohydrate side chains. Exfoliation samples contained a lower amount of the 77 kDa band in comparison to the amount of the 78 kDa band. The lower relative concentration of this transferrin isoform in the exfoliation syndrome samples may be indicative of its possible involvement in the disorder. A different oligosaccharide side chain in combination with a relatively high protein concentration may lead to sedimentation of this molecule. On the other hand, laminin, a glycoprotein detected previously in exfoliation material, contains similar oligosaccharide side chains with transferrin. Thus the oligosaccharide side chains of both proteins may be influenced by the same factors.

Generation of TNF alpha, IFN gamma, IL-6, IL-4 and IL-10 in mouse serum from trichinellosis: effect of the anti-inflammatory compound 4-deoxypyridoxine (4-DPD).

Infections caused by the nematode Trichinella spiralis is characterized in the host by an inflammatory response with cytokine production. In these studies we have detected TNF alpha, IL-6, IFN gamma, IL-4 and IL-10 in the serum of 10 mice infected with T. spiralis. Moreover, we detected, for the first time, these cytokines in the serum of mice treated with 4-DPD, a potent antagonist of vitamin B6 coenzyme which has anti-inflammatory properties. 4-DPD was used at 100, 400, 800 micrograms/bolus for 20 days, starting one day before the infection. After 15 days of T. spiralis infection, TNF alpha reached a maximum level, while IL-6 was maximal after 7 days, IFN gamma at 20 days and IL-4 at 14 days. IL-10 was not affected by the T. spiralis infection. When the animals were treated with 4-DPD at the reported dosages and infected with T. spiralis the inhibition of TNF alpha and IL-6, were dose-dependent in the first 7 days while IL-4 was reduced only at 400-800 micrograms/bolus. 4-DPD-treated mice did not statistically (P > 0.05) affect the generation of IFN gamma. In healthy animals the production of cytokines were not measurable, just as it was in non-infected animals treated with 4-DPD. The increase of cytokines such as, TNF alpha and IL-6 may be related to the severity of the disease, boosting the host's resistance to the pathogen and inhibiting parasite survival. In addition, the augmentation of IL-4 production enhances T and B cells and macrophage responses and may stimulate T-cell antibody-mediated response to the pathogen. 4-DPD, an inhibitor of IL-1 and inflammatory reactions, proved to be most effective on TNF alpha and IL-6, which are mainly produced by macrophages.

Detection of a high molecular weight heparin binding acidic growth factor in human placenta.

A heparin binding fibroblast growth factor with a molecular weight of approximately 45 kDa has been detected in human placenta. The protein was extracted from placenta and purified by a combination of ammonium sulfate precipitation, DE-52 anion exchange chromatography, G100 gel exclusion and heparin sepharose affinity chromatography. The molecule was shown to be monomeric after treatment with beta-mercaptoethanol, and had an acidic isoelectric point. The properties of the polypeptide described in this paper (45 kDa, Pi 4-5, monomeric, heparin binding fibroblast growth factor), suggest that it may represent an as yet undescribed growth factor.

Increased frequency of the rare PstI allele (P2) in a population of CAD patients in northern Greece.

Restriction fragment length polymorphisms (RFLPs) at the apolipoprotein AI-CIII-AIV gene cluster and their association with coronary artery disease (CAD) and lipid levels were studied in a Northern Greek population. Ninety-five patients with CAD and fifty-four normal controls, angiographically proven, were included in this study. Using genomic hybridization techniques, three polymorphic restriction sites were identified at this locus: the PstI at the 3' end of the apoAI gene, the SacI at the 3' non-coding region of the apoCIII gene and the PvuII at the intergenic region between the apoCIII-AIV genes. The rare allele (P2) arising from the absence of the PstI restriction site was observed with a significantly higher frequency (p < 0.01) in patients compared to normals (0.11 vs 0.02). In contrast, the rare allele for the SacI polymorphic site had a similar distribution among patients and controls (0.12 vs 0.16). The same was observed for the PvuII RFLP (0.04 vs 0.05). Correlation of lipid and apolipoprotein AI levels with the three RFLPs revealed no significant association, although apo AI and HDL were lower in patients with the P2 allele. Thus, in this Greek population, only the PstI polymorphism, among the polymorphic restriction sites examined, appears to be associated with CAD.

4-Deoxypyridoxine inhibits chronic granuloma formation induced by potassium permanganate in vivo.

4-Deoxypyridoxine (4-DPD) is a potent antagonist of Vitamin B6 coenzyme which inhibits IL-1, lymphocyte proliferation and has demonstrated that tolerance to skin grafts can be induced by administering splenic cells to pyridoxine-deficient mice. Chronic inflammation induced by dorsal injections of 200 microliters of a 1:40 saturated crystal solution of potassium permanganate (KMnO4) in mice treated or untreated with 4-DPD (400 micrograms/dose), has been investigated. After 7 days all mice developed a subcutaneous granulomatous tissue indicative of a chronic inflammatory response, at the site of injection. KMnO4-treated mice injected intraperitoneally with 4-DPD (400 micrograms/dose) on 5 consecutive days (the first at the same time of induction of the granuloma) show a significant decrease in size and weight of granuloma when compared to mice not treated with 4-DPD (Controls). In addition, in all mice treated with 4-DPD there was a strong inhibition of TNF alpha in serum (P < 0.01) and in supernatant fluids (P < 0.05) from minced granuloma, while IL-6 was inhibited in the supernatant fluids (P < 0.05) of minced granulomas but was not detected in the serum of treated and untreated mice. In this study we show for the first time the antiinflammatory effect of 4-DPD on chronic inflammation and the inhibitory effect of TNF and IL-6 generation in supernatant fluids from minced granulomas.

Rat liver endoplasmic reticulum protein kinases.

1. Rat liver microsomal membranes were studied for the presence of protein kinases. Microsomal proteins solubilized with Triton X-100 were analyzed by means of ion exchange chromatography. 2. Protein kinase activity was detected in the column fractions using specific assays for cAMP-dependent protein kinase, cGMP-dependent protein kinase, protein kinase C, Ca2+/calmodulin-dependent protein kinase and casein kinases. 3. Fractions with protein kinase activity were further analyzed by SDS-polyacrylamide gel electrophoresis. 4. The results indicate that cAMP-dependent protein kinase type I and II, casein kinases I and II, protein kinase C proenzymes I and II and Ca2+/calmodulin kinase II are associated with the membranes of endoplasmic reticulum (ER).

Effect of combination of deoxypyridoxine with known anti-proliferative or immunosuppressive agents on lymphocyte serine hydroxymethyltransferase.

Measurements of serine hydroxymethyltransferase (SHMT) in resting lymphocyte cultures showed that the level of activity of this enzyme is very low. Under the influence of mitogenic stimuli serine hydroxymethyltransferase activity is induced 5-20-fold. Addition in the cultures of 4-deoxypyridoxine (dB6), a potent antagonist of vitamin B6 coenzymes, concurrently with the mitogen, inhibits the induction of SHMT. Separate addition in the cultures of four anti-proliferative (AP) and immunosuppressive (IMS) agents, namely actinomycin, cytarabine, asparaginase and cyclosporine, led to the following observations. (1) The AP and IMS agents produce a decrease in the mitogen-induced activity of SHMT. The higher the concentration of the AP/IMS compound, the greater the decrease of enzymatic activity. (2) When a AP/IMS agent is combined with dB6 its effect on SHMT is considerably greater. (3) Ineffective concentrations of AP/IMS agents become effective when combined with dB6. (4) The observed changes in SHMT activity are not, as one would expect, the same in the case of all four drugs. (5) The combination makes it possible to use much smaller doses of these agents with much better results, at least as far as the decrease of enzymic activity is concerned. This is very promising for clinical use of AP agents in cancer chemotherapy and IMS agents in transplantation especially of the heart and lungs, because combining these compounds with dB6 will make possible to use smaller doses over a longer period of time with greater effectiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

HLA class II DNA-RFLP typing in 102 individuals from Northern Greece.

The serological identification of HLA class II alleles is often doubtful. Since accurate HLA typing is essential for the matching of donor-recipient pairs in allogeneic transplantation, an effort was made to establish DNA restriction fragment length polymorphism (RFLP) typing and to assess the correlation between the serological and RFLP techniques in the population of Northern Greece. One hundred and two healthy individuals (204 HLA-DR alleles) from Northern Greece were HLA-DR, DQ typed with both the microcytotoxicity and the Taq I RFLP method, using three exon-specific probes. DNA-RFLP typing revealed (1) concordant results with serology in 69.9% (142/204) of the alleles and (2) at least one HLA-DR allele discrepant to serology in 30.4% (62/204) of the alleles. Incorrect serological DR types (weak reactions or inability to distinguish between two alleles with a common epitope) were identified in 54 alleles (26.5%), while 3.9% (8/204) of serological "blank" alleles turned out to be definable alleles by RFPL. Of the individuals tested, 10.8% (11/102) were DR-homozygous by RFLP. This comparison of results obtained by serology and RFLP demonstrated the necessity of the clinical application of DNA typing, especially for organ transplantation where accurate HLA typing has an important influence on graft survival.

Effect of pyridoxine deficiency on immunological phenomena.

Measurements of serine hydroxymethyltransferase (SHMT) in resting lymphocyte cultures showed that the level of activity of this enzyme was very low. Under the influence of mitogenic stimuli serine hydroxymethyl-transferase activity was induced 5-20-fold. Addition in the cultures of 4-deoxypyridoxine, a potent antagonist of vitamin B6 coenzymes, concurrently with the mitogen, inhibits the induction of serine hydroxymethyltransferase. Thus deoxypyridoxine exerts its effects not only at the level of the enzyme itself by antagonizing the coenzyme but also at the level of its biosynthesis. Synchronous addition of vitamin B6 with deoxypyridoxine effectively reverses the inhibitory effects. The T helper cells of the lymphocyte culture are very sensitive to deoxypyridoxine action in contrast to T suppressor cells. The effect of phytohaemagglutinin or concanavalin A on the production of interleukin-1b, interleukin-2 and interleukin-2 receptors is profoundly affected by deoxypyridoxine. These results give a deeper insight of the mechanisms by which pyridoxine deficiency causes significant reduction of humoral and cellular immune responses to antigenic stimuli. On the basis of the data of this report a detailed illustration of the events that follow the T cell activation is presented. From this investigation the enzyme serine hydroxymethyltransferase emerges as a key element in the processes of immune responses and cell proliferation. Based on this finding we advance the following two propositions for possible future medical application: (i) combination of deoxypyridoxine with immunosuppressive drugs in case of immunosuppressive therapy or organ transplantation. (ii) the enzyme presents an excellent target for chemotherapy and therefore development of special agents directed against its apoprotein may prove to be a very valuable medical tool.