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A Morelli

Publications and source records attributed to A Morelli.

At least 37 records · Page 2Linked to original sources

Pharmacological and biochemical characterization of A3 adenosine receptors in Jurkat T cells.

1. The present work was devoted to the study of A3 adenosine receptors in Jurkat cells, a human leukemia line. 2. The A3 subtype was found by means of RT-PCR experiments and characterized by using the new A3 adenosine receptor antagonist [3H]-MRE 3008F20, the only A3 selective radioligand currently available. Saturation experiments revealed a single high affinity binding site with K(D) of 1.9+/-0.2 nM and B(max) of 1.3+/-0.1 pmol mg(-1) of protein. 3. The pharmacological profile of [3H]-MRE 3008F20 binding on Jurkat cells was established using typical adenosine ligands which displayed a rank order of potency typical of the A3 subtype. 4. Thermodynamic data indicated that [3H]-MRE 3008F20 binding to A3 subtype in Jurkat cells was entropy- and enthalpy-driven, according with that found in cells expressing the recombinant human A3 subtype. 5. In functional assays the high affinity A3 agonists Cl-IB-MECA and IB-MECA were able to inhibit cyclic AMP accumulation and stimulate Ca(2+) release from intracellular Ca(2+) pools followed by Ca(2+) influx. 6. The presence of the other adenosine subtypes was investigated in Jurkat cells. A1 receptors were characterized using [3H]-DPCPX binding with a K(D) of 0.9+/-0.1 nM and B(max) of 42+/-3 fmol mg(-1) of protein. A2A receptors were studied with [3H]-SCH 58261 binding and revealed a K(D) of 2.5+/-0.3 nM and a B(max) of 1.4+/-0.2 pmol mg(-1) of protein. 7. In conclusion, by means of the first antagonist radioligand [3H]-MRE 3008F20 we could demonstrate the existence of functional A3 receptors on Jurkat cells.

Animals↗

Time course of left ventricular remodeling after stentless aortic valve replacement.

BACKGROUND: Stentless aortic valves are associated with a significant decrease in left ventricular hypertrophy. This study examined the time course and factors affecting left ventricular mass regression (LVMR) after aortic valve replacement (AVR) with Cryolife O'Brien (CLOB) (Cryolife International, Atlanta, Ga) stentless valves. METHODS: Between 1993 and 2000, 130 consecutive patients underwent AVR with CLOB. Mean age was 71.3 +/- 6.3 years. Sixty-four (49.2%) were male. Mean body surface area (BSA) was 1.7 +/- 0.2 m(2). Mean valve size implanted was 23.6 +/- 2.0 mm. All patients were monitored with serial echocardiograms; the first study was performed preoperatively, and subsequent controls were at 6 months, 1, 2, 3, 4, 5, 6, and 7 years, respectively. Left ventricular mass was calculated by the Devereux formula and indexed by BSA. RESULTS: Analysis of variance showed a significant reduction in the left ventricular mass index (LVMI) over time (P < .001). Most LVMRs occurred within the first 6 months, and after 1 year LVMI had decreased by 37.5% with further, but not statistically significant, reductions at later examinations. We found that baseline BSA > 1.75 m(2), male sex, arterial blood pressure > or = 150 mm Hg, left ventricular ejection fraction < or = 35%, New York Heart Association functional class > or = III, non-sinus rhythm, and prevalent aortic incompetence to be factors influencing LVMR. LVMR was not related to postoperative effective orifice area < or = 0.85 cm/m(2) and prosthetic size. CONCLUSIONS: AVR with a CLOB valve is followed by a significant LVMR that occurs soon after surgery. It is influenced by several patient-related factors: most of them can be predicted preoperatively.

Aged↗

NO-mesalamine protects colonic epithelial cells against apoptotic damage induced by proinflammatory cytokines.

The activation of a self-amplifying cascade of caspases, of which caspase-8 is the apical protease, mediates Fas-, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-, and TNF-alpha-induced apoptosis in colon cell lines. Nitric oxide (NO) protects from apoptosis induced by Fas and TNF-alpha. We examined whether NCX-456, an NO-releasing derivative of mesalamine, protects colon epithelial cells from cytokine-induced apoptosis. Caco-2 and HT-29 cell lines express death factor receptors and are driven to apoptosis in response to incubation with Fas-agonistic antibody, TNF-alpha/interferon-gamma, and TRAIL. The two novel observations reported here are that 1) cotreatment of cells with NCX-456, but not mesalamine, resulted in concentration-dependent protection against death factor-induced apoptosis and inhibition of caspase activity, and 2) exposure to dithiothreitol, an agent that effectively removes NO from thiol groups, resulted in a 70% recovery of caspase activity, which is consistent with S-nitrosation as a major mechanism for caspase inactivation. These data suggest that caspase S-nitrosation represents a mechanism for protection of colonic mucosal epithelial cells from death factor-induced death.

Aminosalicylic Acids↗

Nitric oxide-releasing NSAIDs: a review of their current status.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most widely prescribed drugs worldwide owing to their anti-inflammatory, antipyretic and analgesic properties. However, their use is hampered by gastrointestinal (GI) toxicity, the most common drug-related serious adverse event in industrialised nations. Nitric oxide (NO)-releasing NSAIDs, a recently described class of drugs, are generated by adding a nitroxybutyl or a nitrosothiol moiety to the parent NSAID via a short-chain ester linkage. While efficacy of nitrosothiol-NO-NSAIDs still awaits investigation, nitroxybutyl-NO-NSAIDs have been extensively studied in animals, thus the abbreviation NO-NSAIDs used here refers to the latter group of NSAID derivatives. NO-NSAIDs retain the anti-inflammatory and antipyretic activity of original NSAIDs, although they exhibit markedly reduced gastrointestinal toxicity. NO-NSAIDs are nonselective cyclo-oxygenase (COX) inhibitors, and they also exert COX-independent activities that are NO-dependent. Indeed, NO-NSAIDs suppress production of the cytokines interleukin (IL)-1beta, IL-18 and interferon-gamma by causing the S-nitrosilation/inhibition of caspase-1. In acute and chronic animal models of inflammation, it has been demonstrated that NO-NSAIDs abrogated prostaglandin E2 as well as thromboxane B2 generation. In a murine model, NO-naproxen was approximately 10-fold more potent than naproxen in reducing animal writhing after intraperitoneal injection of acetic acid. Similar data have been obtained in chronic models of pain such as rat adjuvant arthritis. In vivo and in vitro studies suggest that NO-aspirin (acetylsalicylic acid) exerts more potent antithrombotic action than aspirin, probably by coupling the ability to inhibit COX-1 with the anti-adhesive effect of NO. Moreover, in a model of renal injury NO-flurbiprofen not only has been demonstrated to be devoid of nephrotoxicity but also to ameliorate renal function. Finally, in an animal model of chronic neurodegenerative disease, NO-flurbiprofen and NO-aspirin attenuated the brain inflammatory response. The GI toxicity of NO-flurbiprofen and NO-naproxen is currently being investigated in healthy individuals.

Animals↗

Early recovery of left ventricular function after stentless versus stented aortic valve replacement for pure aortic stenosis and severe cardiac dysfunction.

OBJECTIVE: The aim of this study was to evaluate early recovery of systolic function after stentless aortic valve replacement (AVR) versus stented AVR. METHODS: Fifty-four consecutive patients with pure aortic stenosis and impaired left ventricular function (LVEF < or = 35%) were studied retrospectively. Aortic regurgitation, concomitant valvular or coronary artery surgery, atrial fibrillation, and a previous AVR were exclusion criteria. Twenty-two patients (mean age, 70.0 +/- 6.5 years) received a stentless bioprosthesis and 32 (mean age, 58.9 +/- 6.2 years, P =.031 between groups) a mechanical or stented biologic valve. Patients underwent echocardiography preoperatively, at discharge, at 6 months, and at 1 year after surgery. RESULTS: At 6 months, analysis of variance demonstrated significant differences between groups in fractional shortening measured at the endocardium and midwall fractional shortening (<0.001), velocity of circumferential shortening (P <.001) ejection fraction (P =.02), left ventricular mass index (P <.001), systolic meridional wall stress, and circumferential wall stress (P <.001), One-year studies confirmed these findings. CONCLUSION: LV function showed, after a stentless AVR, an early recovery greater than in patients receiving a stented valve.

Aged↗

IL-1 beta converting enzyme is a target for nitric oxide-releasing aspirin: new insights in the antiinflammatory mechanism of nitric oxide-releasing nonsteroidal antiinflammatory drugs.

Caspase-1, the IL-1beta converting enzyme (ICE), is required for intracellular processing/maturation of IL-1beta and IL-18. NO releasing nonsteroidal antiinflammatory drugs (NSAIDs) are a new class of NSAID derivatives that spare the gastric mucosa. Here, we tested the hypothesis that NCX-4016, a NO-aspirin derivative, inhibits proinflammatory cytokine release from endotoxin (LPS)-challenged monocytes. Our results demonstrated that exposing LPS-stimulated human monocytes to NCX-4016 resulted in a 40-80% inhibition of IL-1beta, IL-8, IL-12, IL-18, IFN-gamma, and TNF-alpha release with an EC(50) of 10-20 microM for IL-1beta and IL-18. Incubating LPS-primed monocytes with NCX-4016 resulted in intracellular NO formation as assessed by measuring nitrite/nitrate, intracellular cGMP concentration, and intracellular NO formation. Exposing LPS-stimulated monocytes to aspirin or celecoxib caused a 90% inhibition of prostaglandin E(2) generation but had no effect on cytokine release. NCX-4016, similar to the NO donor S-nitroso-N-acetyl-D-L-penicillamine, inhibited caspase-1 activity with an EC(50) of approximately 20 microM. The inhibition of caspase-1 by NCX-4016 was reversible by the addition of DTT, which is consistent with S-nitrosylation as the mechanism of caspase-1 inhibition. NCX-4016, but not aspirin, prevented ICE activation as measured by assessing the release of ICE p20 subunit. IL-18 immunoneutralization resulted in a 60-80% reduction of IL-1beta, IL-8, IFN-gamma, and TNF-alpha release from LPS-stimulated monocytes. Taken together, these data indicate that incubating human monocytes with NCX-4016 causes intracellular NO formation and suppresses IL-1beta and IL-18 processing by inhibiting caspase-1 activity. Caspase-1 inhibition is a new, cycloxygenase-independent antiinflammatory mechanism of NO-aspirin.

Anti-Inflammatory Agents, Non-Steroidal↗

Evidence of a linkage disequilibrium between polymorphisms in the human estrogen receptor alpha gene and their relationship to bone mass variation in postmenopausal Italian women.

Bone mineral density (BMD), the major determinant of osteoporotic fracture risk, has a strong genetic component. The discovery that inactivation of estrogen receptor alpha (ERalpha) gene is associated with low BMD indicated ERalpha as a candidate gene for osteoporosis. We have investigated the role of three ERalpha gene polymorphisms [intron 1 PVU:II and XBA:I RFLPs and TA dinucleotide repeat polymorphism 5' upstream of exon 1] in 610 postmenopausal women. There was a strong linkage disequilibrium between intron 1 polymorphic sites and also between these sites and the microsatellite (TA)(n) dinucleotide polymorphism, with a high degree of coincidence of the short TA alleles and the presence of PVU:II and XBA:I restriction sites. No significant relationship between intron 1 RFLPs and BMD was observed. A statistically significant correlation between (TA)(n) repeat allelic variants and lumbar BMD was observed (P = 0.04, ANCOVA), with subjects with a low number of repeats (TA < 15) showing the lowest BMD values. We observed a statistically significant difference in the mean +/- SD number of TA repeats between analyzed women with a vertebral fracture (n = 73) and the non-fracture group, equivalent to 2.9 (95% CI 1.56-5.72) increased fracture risk in women with a low number of repeats (TA < 15). We conclude that in this large population sample the (TA)(n) dinucleotide repeat polymorphism at the 5' end of the ERalpha gene accounts for part of the heritable component of BMD and might prove useful in the prediction of vertebral fracture risk in postmenopausal osteoporosis.

Alleles↗

ATP synthesis in rod outer segments of bovine retina by the reversal of the disk Ca(2+) pump.

Purified disk membranes from rod outer segments of the bovine retina were able to synthesize ATP with a maximal activity (about 52 nmoles ATP/min/mg of protein) at physiological calcium concentrations. This activity was inhibited by vanadate or thapsigargin but not by oligomycin, suggesting the reversal functioning of the disk Ca(2+)-ATPase, which would act as a ATP synthesizer at the expense of the calcium gradient between the disks and the cytoplasm of the rod outer segment. The results are discussed in terms of the need of an immediate source of ATP on the disk membranes where the energy is required to supply the rapid reactions of the photoreception processes.

Adenosine Diphosphate↗

Galectin-1 exerts immunomodulatory and protective effects on concanavalin A-induced hepatitis in mice.

Galectin-1, an endogenous lectin with immunomodulatory activities, induces selective, Fas-independent apoptosis of activated T cells. The aim of the present study was to evaluate the effect galectin-1 exerts on concanavalin A (Con A)-induced hepatitis, a T-cell-dependent model of liver injury. Con A administration resulted in liver injury, as shown by the increased transaminase plasma levels and liver DNA fragmentation, and caused spleen T-cell activation, which was associated with a strong increment in liver infiltrating T helper cells. Moreover, Con A injection leads to a marked increase in plasma tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) levels. Galectin-1 pretreatment dose-dependently prevented both liver injury and T-helper cell liver infiltration induced by Con A. In vivo and in vitro experiments indicated that the protective effects of galectin-1 depend on the selective elimination of Con A-activated T cells. In addition, galectin-1 almost completely prevented the Con A-induced increase in plasma TNF-alpha and IFN-gamma, an effect that was, at least in part, independent on the elimination of activated T helper cells, because galectin-1 prevented lipopolysaccharide (LPS)-induced release of TNF-alpha and IFN-gamma also from macrophages in vitro, without affecting their viability. The present study suggests that galectin-1 is potentially useful in the treatment of T-cell-mediated human liver disorders.

Adjuvants, Immunologic↗

High glucose modulates P2X7 receptor-mediated function in human primary fibroblasts.

AIMS/HYPOTHESIS: Purinergic receptors are a family of newly characterized plasma membrane molecules involved in several and as yet only partially known cellular functions such as vascular reactivity, apoptosis and cytokine secretion. Little is known about the effect extracellular microenvironment has on their function. Fibroblasts share several features with smooth muscle cells and are an important constituent of the atherosclerotic plaque. Our aim was to evaluate the effect of high glucose concentration on ATP-mediated responses in human fibroblasts. METHODS: Fibroblasts were obtained by skin biopsies and grown at two different glucose concentrations. We evaluated receptor expression by RT-PCR and immunoblotting and receptor localization by immunofluorescence. Plasma membrane potential and calcium changes were measured by fluorescent indicators. Apoptosis was determined by ethidium bromide staining and caspase-3 activation. RESULTS: We show that cells grown in a medium with high glucose concentration underwent great ATP-mediated morphological changes, enhanced apoptosis, caspase 3 activation and interleukin-6 release. We identified P2X7 as the main purinergic receptor involved in these responses. Furthermore, high glucose concentration triggered the assembly of P2X7 into ring-like structures located at the periphery of the cells. CONCLUSION/INTERPRETATION: Given that ATP is frequently released into the extracellular milieu upon cell and tissue damage, secretory exocytosis or activation of plasma membrane transporters, we hypothesize that ATP receptors participate in the pathogenesis of vascular complications of diabetes.

Adenosine Triphosphate↗

NO-aspirin protects from T cell-mediated liver injury by inhibiting caspase-dependent processing of Th1-like cytokines.

BACKGROUND & AIMS: Concanavalin A (con A)-induced hepatitis is an immunomediated disease in which assembly of CD4(+) T cells and T helper (Th)1-like cytokines causes Fas-mediated liver cell death. Nitric oxide (NO) modulates Th1 response in vitro. NCX-4016 is an NO-aspirin derivative that spares the gastrointestinal tract and shares molecular targets with NO. The aim of this study was to investigate whether this NO-aspirin modulates Th1-like response induced by con A. METHODS: BALB/c mice were injected with 0.3 mg con A per mouse alone or in combination with NO-aspirin (18-100 mg/kg) or aspirin (10-55 mg/kg). RESULTS: NO-aspirin, but not aspirin, caused a dose-dependent protection against liver damage induced by con A. At a dose of 100 mg/kg, NO-aspirin caused a 40%-80% reduction of interleukin (IL)-1beta, IL-12, IL-18, interferon (IFN)-gamma, and tumor necrosis factor alpha production without affecting cytokine messenger RNA expression. NO-aspirin prevented Fas, Fas ligand, and IL-2 receptor up-regulation on spleen lymphocytes and Fas ligand on hepatocytes and caused the S-nitrosylation/inhibition of IL-1beta-converting enzyme-like cysteine proteases (caspases) involved in the processing and maturation of IL-1beta and IL-18. IL-18 immunoneutralization prevented IFN-gamma release and protected from liver injury induced by con A. In contrast to a selective caspase 1 inhibitor, zVAD.FMK, a pancaspase inhibitor, prevented IFN-gamma release and protected the liver from injury. CONCLUSIONS: Th1-like response induced by con A is mediated by IL-18 and requires activation of multiple caspases. NCX-4016 causes the S-nitrosylation/inhibition of caspases involved in cytokine production. Inhibition of Th1-like response is a new anti-inflammatory mechanism of action of NO-aspirin.

Amino Acid Chloromethyl Ketones↗

Cellular responses to Loa loa experimental infection in mandrills (Mandrillus sphinx) vaccinated with irradiated infective larvae.

In order to shed light on the mechanisms of antifilarial protective immunity, we investigated the course of experimental loaiosis after vaccination in a nonhuman primate host, Mandrillus sphinx. Six vaccinated (V) mandrills received 50 irradiated L3 while six nonvaccinated (NV) received saline solution on days -60, -30 and -15. All animals were challenged with 100 intact L3 (day 0). Parasitological and immunological status were followed for 9 months. Vaccination delayed the appearance and mean peak of microfilaraemia. Five mandrills (Mf-) were never microfilaraemic (one V mandrill) or microfilaraemic on only one occasion (2 V and 2 NV), the other seven having stable microfilaraemia (Mf+). The cytokine response of peripheral blood mononuclear cells to L3 (L3 Ag) was Th2 dominated, while microfilariae (Mf Ag) elicited a Th0-like response. During vaccination, Th2 cytokine production significantly increased in V mandrills against L3 Ag, as well as Mf Ag, whereas Th1 cytokines decreased. On day 60 postinoculation, cellular proliferation was higher in V mandrills in response to L3 and Mf Ags and PHA-L mitogen. At the end of prepatency (on day 130), mandrills with delayed appearance of microfilaraemia exhibited a high, transient IL-2 and IL-4 secretion in response to L3 Ag. Finally, high anti-Mf Th2 cytokine levels characterized Mf-mandrills not only during prepatency, but also (for IL-5) before immunization. However, the presence of a balanced Th1 anti-L3 response during prepatency in the amicrofilaraemic mandrill suggests its importance in protective immunity. Taken together, our data suggest that Th2 cells and also Th1 components of the antifilarial response, especially to larval antigen, may contribute to parasite elimination.

Animals↗

The P2 purinergic receptors of human dendritic cells: identification and coupling to cytokine release.

We investigated the expression of purinoceptors in human dendritic cells, providing functional, pharmacological, and biochemical evidence that immature and mature cells express P2Y and P2X subtypes, coupled to increase in the intracellular Ca(2+), membrane depolarization, and secretion of inflammatory cytokines. The ATP-activated Ca(2+) change was biphasic, with a fast release from intracellular stores and a delayed influx across the plasma membrane. A prolonged exposure to ATP was toxic to dendritic cells that swelled, lost typical dendrites, became phase lucent, detached from the substrate, and eventually died. These changes were highly suggestive of expression of the cytotoxic receptor P2X(7), as confirmed by ability of dendritic cells to become permeant to membrane impermeant dyes such as Lucifer yellow or ethidium bromide. The P2X(7) receptor ligand 2',3'-(4-benzoylbenzoyl)-ATP was a better agonist then ATP for Ca(2+) increase and plasma membrane depolarization. Oxidized ATP, a covalent blocker of P2X receptors, and the selective P2X(7) antagonist KN-62 inhibited both permeabilization and Ca(2+) changes induced by ATP. The following purinoceptors were expressed by immature and mature dendritic cells: P2Y(1), P2Y(2), P2Y(5), P2Y(11) and P2X(1), P2X(4), P2X(7). Finally, stimulation of LPS-matured cells with ATP triggered release of IL-1 beta and TNF-alpha. Purinoceptors may provide a new avenue to modulation of dendritic cells function.

Adenosine Triphosphate↗

MEN1 gene mutation analysis in Italian patients with multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN 1) is a familial syndrome characterized by parathyroid, enteropancreatic and pituitary tumors. The gene responsible for this syndrome is localized at chromosomal 11q13 region and DNA markers from this region cosegregate with the disease. The recent identification of the MEN1 gene, encoding for a protein termed menin of 610 amino acids, allowed mutational screening to be performed both in affected families and sporadic cases. To date many different heterozygous mutations, spreading across all the encoding sequence, have been identified in MEN 1 patients with no apparent mutational hot spots or genotype-phenotype correlation. To analyze the genetic alterations of the MEN1 gene occurring in Italian patients we performed mutational screening by Denaturant Gradient Gel Electrophoresis followed by sequencing of exons 2-10 of the MEN1 gene in 27 Italian MEN 1 families and in five sporadic cases. We identified 17 different heterozygous mutations in 60% of analyzed cases. Twelve of these mutations are novel. Two mutations each occurred twice in unrelated families but no evidence of genotype-phenotype correlation can be established for these families. The extension of genetic diagnosis to asymptomatic family members allowed the identification of 10 MEN1 mutant gene carriers, one newly described and nine previously detected by linkage analysis with DNA markers from the 11q13 region. Our findings add new information to the diversity of mutations occurring in the MEN1 gene and confirm that the mutational screening of MEN 1 is a useful approach to detect individuals at higher risk of developing MEN 1-associated tumors.

DNA Mutational Analysis↗

Mouse dendritic cells express the P2X7 purinergic receptor: characterization and possible participation in antigen presentation.

Immune cells express P2 purinoceptors of the P2Y and P2X subtypes. In the present work, we show that three dendritic cell (DC) lines, D2SC/1, CB1, and FSDC, representative of immature DCs, express the P2X7 (formerly P2Z) receptor, as judged from RT-PCR amplification, reactivity to a specific antiserum, and pharmacological and functional evidence. Receptor expression is higher in FSDC cells, a cell line that is functionally more mature than D2SC/1 and CB1. From the wild-type DC population, we selected cell clones lacking the P2X7R (P2X7less). We also used a P2XR blocker, oxidized ATP, to irreversibly inhibit the P2X7R. Ability of P2X7less FSDCs or of oxidized ATP-inhibited FSDCs to stimulate Ag-specific TH lymphocytes was severely decreased although Ag endocytosis was minimally affected. During coculture with TH lymphocytes, wild-type FSDC secreted large amounts of IL-1beta. Release of this cytokine was reduced in P2X7less DCs. These data show that DCs express the P2X7 purinoceptor and suggest a correlation between P2X7R expression and Ag-presenting activity.

Adenosine Triphosphate↗

Telomerase repeat amplification protocol (TRAP): A new molecular marker for parathyroid carcinoma.

Telomerase results to be active in human germ, stem cells, several malignant cell tumors and in immortalized cell lines. In order to investigate if molecular mechanisms other than Rb gene inactivation can be helpful to diagnose malignancy of parathyroid tumors, we decided to investigate the presence of active telomerase in homogenates from different pathological parathyroid tissues (hyperplastic, adenomatous, carcinomatous, and normal) and primary cell cultures. The TRAP assay was performed to detect this activity in histologically characterized normal, hyperplastic, adenomatous, and carcinomatous human parathyroid tissues, primary cell lines, and one metastatic tissue from parathyroid carcinoma. Only malignant parathyroid glands and the metastatic tissue were TRAP positive. Our findings suggest that telomerase expression could represent an important molecular mechanism underlying the acquisition and progression of an aggressive phenotype of epithelial parathyroid cells and it may help to predict their malignant potential. The TRAP assay is easy to perform and it could become an additional tool to be included in the harmamentarium for the molecular diagnosis of parathyroid carcinoma.

Biomarkers, Tumor↗

Plasmodium coatneyi: differential clinical and immune responses of two populations of Macaca fascicularis from different origins.

Two species of macaques, including two Macaca fascicularis from the Philippines, two M. fascicularis from Mauritius, and one Macaca mulatta, were experimentally infected with blood stages of Plasmodium coatneyi and followed during their clinical, parasitological, biological, and immunological evolution. Plasma cytokine (TNF-alpha, IL-1beta, IL-6, IFN-gamma) production peaked for all monkeys 11 days after inoculation, concomitantly with peaks of parasitemia. Only the M. fascicularis from the Philippines survived the infection. The main features, which discriminated nonfatal from fatal cases, were the observation in M. fascicularis from the Philippines of a mean CD4+/CD8+ ratio below I and of their ability, as revealed by mitogenic stimulation of whole blood, to produce increasing amounts of IFN-gamma as infection evolved. The contribution of environmental and genetic factors, which may differentiate the three groups of monkeys and therefore explain fatal or nonfatal evolution of the infection among them, is discussed.

Anemia↗