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J Marco

Publications and source records attributed to J Marco.

At least 91 records · Page 5Linked to original sources

Influence of glucose concentration on the inhibitory effect of amylin on insulin secretion. Study in the perfused rat pancreas.

The effect of amylin on insulin secretion is a matter of controversy. Short-term experiments have shown that amylin, at 75 pmol/l, inhibits the insulin release elicited by a modest increase in the perfusate glucose concentration (from 5.5 mmol/l to 9 mmol/l). The present work was undertaken to further investigate the effect of amylin on glucose-induced insulin release at different glucose concentrations. The study was performed in the isolated perfused rat pancreas. Amylin, at 75 pmol/l, markedly blocked the insulin response when the perfusate glucose concentration was increased from 3.2 mmol/l to 7 mmol/l (by 90%; P < 0.01) or from 5.5 mmol/l to 9 mmol/l (by 80%; P < 0.01). At the same amylin concentration, no significant inhibition of insulin output was observed when the perfusate glucose level was augmented from 5.5 mmol/l to 16.6 mmol/l, from 7 mmol/l to 11 mmol/l or from 9 mmol/l to 13 mmol/l. At a higher concentration (750 pmol/l), amylin also failed to inhibit the insulin response induced by increasing glucose levels from 5.5 mmol/l to 16.6 mmol/l or from 9 to 13 mmol/l. These findings indicate that, in the rat pancreas, amylin only inhibits insulin release when evoked by elevations of glucose levels comparable to those occurring in normal subjects under physiological conditions.

Amyloid↗

Ticlopidine and aspirin pretreatment reduces coagulation and platelet activation during coronary dilation procedures.

OBJECTIVES: It is unknown whether a therapeutic combination of aspirin (ASA) and ticlopidine might effectively decrease activation of hemostasis. BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA), rotational atherectomy and stent implantation are procedures that fracture or ablate endothelium and plaque, a situation that activates hemostasis. METHODS: In 85 patients undergoing PTCA for a 77.8 +/- 1% stenosis, we measured markers of coagulation and platelet activation (thrombin-antithrombin complexes [TAT], prothrombin fragment 1 + 2 [F1 + 2] serotonin and the presence of circulating activated platelets reacting with monoclonal antibodies against glycoproteins exposed on platelet membranes). Blood samples were drawn from a peripheral vein and from the coronary ostium before the procedures. Both immediately and 10 min after angioplasty, and 10 min afterward, samples were collected from a probing catheter (0.018 in, [0.46 cm]) positioned beyond the stenosis. All patients were being treated with antianginal drugs and ASA, 250 mg/day. Seventy of them had taken ticlopidine, 250 mg, twice daily for < or = 1 day (< or = 24 h) (n = 28) or for > or = 3 days (> or = 72 h) (n = 42). Heparin (150 U/kg) was administered before angioplasty. Thirty patients underwent PTCA; 15 of them were not treated with ticlopidine and 15 were given ticlopidine (> or = 72 h). Thirty-five patients had stent implantation, 20 rotational atherectomy. RESULTS: Before and during the procedures, there was greater thrombin generation (expressed by higher TAT and F1 + 2 plasma levels) in patients not taking ticlopidine or taking it for < or = 24 h (p < 0.05). Platelet activation and plasma serotonin levels were also significantly higher in the no ticlopidine or < or = 24-h ticlopidine groups. CONCLUSIONS: The combined use of ticlopidine, ASA and heparin effectively controls activation of coagulation in patients with stable or unstable angina undergoing coronary dilation.

Angioplasty, Balloon, Coronary↗

First international new intravascular rigid-flex endovascular stent study (FINESS): clinical and angiographic results after elective and urgent stent implantation. The FINESS Trial Investigators.

OBJECTIVES: The purpose of this study was to determine the feasibility, safety and efficacy of elective and urgent deployment of the new intravascular rigid-flex (NIR) stent in patients with coronary artery disease. BACKGROUND: Stent implantation has been shown to be effective in the treatment of focal, new coronary stenoses and in restoring coronary flow after coronary dissection and abrupt vessel closure. However, currently available stents either lack flexibility, hindering navigation through tortuous arteries, or lack axial strength, resulting in suboptimal scaffolding of the vessel. The unique transforming multicellular design of the NIR stent appears to provide both longitudinal flexibility and radial strength. METHODS: NIR stent implantation was attempted in 255 patients (341 lesions) enrolled prospectively in a multicenter international registry from December 1995 through March 1996. Nine-, 16- and 32-mm long NIR stents were manually crimped onto coronary balloons and deployed in native coronary (94%) and saphenous vein graft (6%) lesions. Seventy-four percent of patients underwent elective stenting for primary or restenotic lesions, 21% for a suboptimal angioplasty result and 5% for threatened or abrupt vessel closure. Fifty-two percent of patients presented with unstable angina, 48% had a previous myocardial infarction, and 45% had multivessel disease. Coronary lesions were frequently complex, occurring in relatively small arteries (mean [+/-SD] reference diameter 2.8 +/- 0.6 mm). Patients were followed up for 6 months for the occurrence of major adverse cardiovascular events. RESULTS: Stent deployment was accomplished in 98% of lesions. Mean minimal lumen diameter increased by 1.51 +/- 0.51 mm (from 1.09 +/- 0.43 mm before to 2.60 +/- 0.50 mm after the procedure). Mean percent diameter stenosis decreased from 61 +/- 13% before to 17 +/- 7% after intervention. A successful interventional procedure with < 50% diameter stenosis of all treatment site lesions and no major adverse cardiac events within 30 days occurred in 95% of patients. Event-free survival at 6 months was 82%. Ninety-four percent of surviving patients were either asymptomatic or had mild stable angina at 6 month follow-up. CONCLUSIONS: Despite unfavorable clinical and angiographic characteristics of the majority of patients enrolled, the acute angiographic results and early clinical outcome after NIR stent deployment were very promising. A prospective, randomized trial comparing the NIR stent with other currently available stents appears warranted.

Aged↗

Corynebacterium mastitidis sp. nov., isolated from milk of sheep with subclinical mastitis.

Fourteen strains of a hitherto unknown catalase-positive, aerobic, gram-positive coryneformlike organism were isolated from the milk of sheep with subclinical mastitis from different regions of Spain. The strains phenotypically closely resembled one another and biochemically were similar to Corynebacterium urealyticum and Corynebacterium afermentans subsp. lipophilum. The results of chemotaxonomic investigations were consistent with membership in the genus Corynebacterium, and comparative 16S rRNA gene sequencing studies showed that the unknown bacterium from sheep was indeed a member of the genus Corynebacterium. Within the genus Corynebacterium the new bacterium formed a distinct subline that exhibited > 4% sequence divergence with other species. Based on both phenotypic and phylogenetic findings, a new species, Corynebacterium mastitidis, is proposed for the organisms from mastitic sheep. The type strain of C. mastitidis is CECT 4843 (= S-8).

Animals↗

Ticlopidine and aspirin interactions.

The risk-benefit balance when aspirin is compared with aspirin combined with ticlopidine is being investigated in several multicentre trials (MUSIC and WEST II versus TASTE, MUST, and STARS respectively). Cardiologists follow one of two strategies. Some prefer a more aggressive antiplatelet regimen, disregarding the risk of neutropenia (0.7%) because they want to avoid lessening the therapeutic effect of vessel patency obtained with stent implantation. Others give only aspirin (a money saving approach) confident that IVUS inspection (an expensive approach) will allow an adequate evaluation of full stent expansion and lesion coverage, despite a more pronounced activation of the coagulation cascade. Our impression so far is that the combination of ticlopidine and aspirin has a more favourable risk-effect balance.

Angioplasty, Balloon, Coronary↗

Intracoronary stent implantation without ultrasound guidance and with replacement of conventional anticoagulation by antiplatelet therapy. 30-day clinical outcome of the French Multicenter Registry.

BACKGROUND: Stenting reduces both acute complications of coronary angioplasty and restenosis rates but increases subacute thrombosis rates and hemorrhagic complications when used with coumadin anticoagulation. METHODS AND RESULTS: To simplify postcoronary stenting treatment and to reduce these drawbacks, we evaluated the 1-month outcome of a prospective registry of 2900 patients in whom successful coronary artery stenting was performed without coumadin anticoagulation. Patients received 100 mg/d aspirin and 250 mg/d ticlopidine for 1 month. Low-molecular-weight heparin (LMWH) treatment was progressively reduced in four consecutive stages, from 1-month treatment to none. Event-free outcome at 1 month was achieved in 2816 patients (97.1%). Major stent-related cardiac events were subacute closure in 51 patients (1.8%), including death in 12 (0.5%), acute myocardial infarction in 17 (0.6%), and coronary artery bypass graft surgery in 9 (0.3%). Stent thrombosis was more frequent with balloon size of < 3.0 mm (< or = 2.5 mm, 10%; 3.0 mm, 2.3%; > or = 3.5 mm, 1.0%; P < .001), bail-out situations (6.67% versus 1.38%, P < .001), and patients with unstable angina or acute myocardial infarction (2.2% versus 1.12%, P = .02). Bleeding complications that required transfusion, surgical repair, or both occurred in 55 patients (1.9%). Bleeding complications were related to female gender (4.0% versus 1.51%, P < .001), duration of LMWH treatment (3.83% in phase II/III versus 0.69% in phase IV/V, P < .001), sheath size (6F, 0.52%; 7F, 1.04%; > or = 8F, 4.23%; P < .001), bail-out situations (4.76% versus 1.67%, P < .01), and saphenous graft stenting (4.38% versus 1.75%, P = .04). CONCLUSIONS: These results suggest that poststenting treatment by ticlopidine/aspirin is an effective alternative to coumadin anticoagulation, achieving low rates of subacute closure and bleeding complications. LMWH treatment does not improve subacute reocclusion rates but increases bleeding complications. Furthermore, as bleeding complications were independently related to sheath size, we suggest that stenting with 6F guiding catheters may prevent local complications. Furthermore, the ticlopidine/aspirin combination allows a low-cost stenting strategy without ultrasound assessment of stent deployment and permits short inhospital stay.

Aged↗

Influence of acute myocardial infarction location on in-hospital and late outcome after primary percutaneous transluminal coronary angioplasty versus tissue plasminogen activator therapy.

In the Primary Angioplasty in Myocardial Infarction trial, 395 patients with acute myocardial infarction (AMI) were prospectively randomized to tissue plasminogen activator (tPA) or primary percutaneous transluminal coronary angioplasty (PTCA). In 138 patients with anterior wall AMI, in-hospital mortality was significantly reduced by treatment with PTCA compared with tPA (1.4% vs 11.9%, p = 0.01). PTCA also resulted in lower rates of death or reinfarction (1.4% vs 18.0%, p = 0.0009), recurrent myocardial ischemia (11.3% vs 28.4%, p = 0.01), and stroke (0.0% vs 6.0%, p = 0.037) in anterior wall AMI. The independent beneficial effect of treatment with primary PTCA rather than tPA in anterior wall AMI was confirmed by multivariate analysis and interaction testing. The in-hospital mortality of 257 patients with nonanterior wall AMI was similar after PTCA and tPA (3.2% vs 3.8%, p = 0.82). Compared with tPA, however, primary PTCA resulted in a markedly lower rate of recurrent myocardial ischemia (9.7% vs 27.8%, p = 0.0002), fewer unscheduled catheterization and revascularization procedures, and a shorter hospital stay (7.0 vs 8.6 days, p = 0.01) in nonanterior wall AMI. Thus, compared with tPA, primary PTCA in patients with anterior wall AMI results in significantly improved survival, with lower rates of stroke, reinfarction, and recurrent myocardial ischemia. In nonanterior wall AMI, treatment with PTCA and tPA results in similar early mortality, although PTCA-treated patients have a more stable hospital course characterized by reduced recurrent ischemia, fewer subsequent invasive procedures, and earlier discharge.

Angioplasty, Balloon, Coronary↗

Outcome of different reperfusion strategies in patients with former contraindications to thrombolytic therapy: a comparison of primary angioplasty and tissue plasminogen activator. Primary Angioplasty in Myocardial Infarction (PAMI) Investigators.

High-risk patients have been excluded from most thrombolytic trials because of concern over hemorrhagic complications or lack of efficacy. However, based on several recent studies suggesting that patients with relative thrombolytic contraindications may also benefit from reperfusion, recommendations have been made to broadly expand the eligibility criteria for thrombolytic therapy, despite higher absolute complication rates. Primary percutaneous transluminal coronary angioplasty (PTCA) may be an attractive alternative for patients presenting at appropriately equipped hospitals who would otherwise remain at high risk after thrombolytic therapy. In the Primary Angioplasty in Myocardial Infarction (PAMI) trial, 395 patients with acute myocardial infarction were randomized to tissue plasminogen activator (t-PA) or primary PTCA. Conditions were present in 151 patients (38%) which formerly would have contraindicated thrombolytic therapy (age > 70 yr, symptom duration > 4 hr, or prior bypass surgery). In-hospital mortality was 4.3-fold higher in patients with former thrombolytic contraindications compared to lytic-eligible patients (8.6% vs. 2.0%, P = .002). Lytic-eligible patients treated with t-PA and PTCA had similar in-hospital mortality (1.7% vs. 2.4%, P = NS). In contrast, both in-hospital (2.9% vs. 13.2%, P = .025) and 6-mo mortality (2.9% vs. 15.7%, P = .009) were significantly reduced in patients with former thrombolytic contraindications treated by primary PTCA compared to t-PA. By logistic regression analysis, treatment by PTCA rather than t-PA was the strongest predictor of survival in patients with former thrombolytic contraindications. We conclude that patients with conditions formerly contraindicating thrombolytic therapy constitute a high-risk group with significant morbidity and mortality after lytic reperfusion. Our data suggest that patients with former contraindications to thrombolytic therapy may benefit by preferential management with primary PTCA without antecedent thrombolysis.

Aged↗

Can we optimize our angiographic views every time? Qualitative and quantitative evaluation of a new functionality.

RATIONALE AND OBJECTIVES: For determining the optimum angulations of the x-ray beam with respect to the vascular morphology of a given patient, the authors present a solution combining a single-plane angiographic system and a dedicated procedure. METHODS: The clinical evaluation of the vessel profiling acquisitions focuses on qualitative appraisal and quantitative analysis of conventional and optimum projections. RESULTS: The qualitative evaluation demonstrates the pitfall for an operator to discern optimum from conventional projections. The 70% of preferences for vessel profiling bear witness to the constraints imposed occasionally by the optimum angulations, which may be impracticable for various reasons. However, vessel profiling yields lesions inspection at an optimum view, free of geometric foreshortening. Moreover, there is less risk of superimposition with other branches. From a quantitative standpoint, vessel profiling unveils the lesion with a length significantly longer than in conventional view. CONCLUSIONS: Vessel profiling offers a qualitative optimization of angiographic images and more exact quantitative analysis.

Angiocardiography↗

Effect of (8-32) salmon calcitonin, an amylin antagonist, on insulin, glucagon and somatostatin release: study in the perfused pancreas of the rat.

1. The 8-32 fragment of salmon calcitonin ((8-32) sCT) has been proposed as a highly selective amylin receptor antagonist. 2. In the present study, we have studied the influence of (8-32) sCT on the inhibitory effect of both amylin and its structural congener, calcitonin gene-related peptide (CGRP), on insulin secretion in the rat perfused pancreas. 3. Both amylin and CGRP, at 75 pM, clearly inhibited glucose-induced insulin release (by 80% and by 70%, respectively). Simultaneous infusion of 10 microM (8-32) sCT reversed the inhibitory effect of amylin (by 80%; P < 0.05 vs. amylin experiments) but did not significantly affect the inhibition of glucose-induced insulin output elicited by CGRP. Furthermore, at the same concentration (10 microM), (8-32) sCT alone potentiated the insulin response to 7 mM glucose (2.5 fold; P < 0.05) whilst it did not affect glucagon or somatostatin secretion. 4. The observation that infusion of an amylin antagonist into the rat pancreas potentiates the insulin response to glucose, favours the concept of endogenous amylin as an inhibitor of insulin release. 5. Finally, as an amylin antagonist at the level of the beta-cell, (8-32) sCT might be considered of potential interest in experimental and clinical pharmacology.

Amyloid↗

Effect of enterostatin on insulin, glucagon, and somatostatin secretion in the perfused rat pancreas.

Enterostatin is a pentapeptide generated by trypic digestion of procolipase in the small intestine. Both peripheral and central administration of this peptide to rats has been shown to reduce food intake, this reduction being due to specific suppression of fat intake. In perifused pancreatic rat islets, enterostatin has been shown to inhibit the insulin response to a high glucose concentration. In the present study, we have investigated the effect of exogenous enterostatin on insulin, glucagon, and somatostatin secretion by the isolated perfused rat pancreas. Enterostatin, at 100 mmol/l, inhibited the insulin response to 9 mmol/l glucose (by 70%), 0.1 mmol/l tolbutamide (by 40%), and 5 mmol/l arginine (by 70%). Enterostatin had no effect on glucagon and somatostatin release at a maintained glucose level (5.5 mmol/l) or in response to 5 mmol/l arginine. Finally, preinfusion of the rat pancreas with a high enterostatin concentration (500 nmol/l) did not alter the insulin response to glucose, an observation that would rule out a toxic effect of this peptide on the beta-cell. In summary, in the perfused rat pancreas, enterostatin, at putatively physiological concentrations, inhibits insulin secretion without affecting glucagon or somatostatin output, thus pointing to a direct effect of enterostatin on the beta-cell and not through an alpha-cell or delta-cell paracrine effect. Because enterostatin is generated in the small intestine after feeding, it might play a role in the enteroinsular axis as an anti-incretin agent.

Animals↗

Effects of luteinizing hormone-releasing hormone on pulsatile prolactin secretion in adult hyperprolactinemic female rats.

Regulation of prolactin secretion involves complex interactions of multiple inhibitory and stimulatory factors. Among them, luteinizing hormone-releasing hormone (LHRH) has been shown, when analyzed in single samples, to exert both stimulatory and inhibitory influences on prolactin secretion. In the present study, we have further examined the effects of LHRH on prolactin secretion by studying the pulsatile pattern of the hormone after the administration of the neuropeptide. For this purpose, adult sham-operated and pituitary-grafted female rats, exhibiting diestrus smears were bled for 3 hr during the morning (1030 to 1330 hr). Two pulses of LHRH (10 ng/kg body wt) were administered 60 and 120 min after starting the bleeding period. Pituitary grafting increased the mean serum prolactin levels, absolute amplitude of the hormone peaks, and its mean half-life, compared with control animals. In sham-operated rats, LHRH administration diminished mean serum prolactin levels, the absolute pulse amplitude and frequency of prolactin peaks. In pituitary-grafted animals, LHRH administration only decreased the pulse frequency of prolactin peaks. These data suggest that LHRH significantly suppressed pulsatile prolactin secretion, and that this effect was blunted by exposure to previously elevated circulating prolactin levels.

Animals↗

Kaposi's sarcoma with an intense parasitization by Leishmania.

Visceral leishmaniasis has been reported as a complication in patients infected with human immunodeficiency virus (HIV) who live in areas where leishmaniasis is endemic or in patients who have traveled to these areas. Kaposi's sarcoma has been found frequently in patients with acquired immunodeficiency syndrome (AIDS). We report a HIV-infected patient having visceral leishmaniasis associated with Kaposi's sarcoma in which a biopsy specimen obtained from a pigmented cutaneous lesion revealed the coexistence of a Kaposi's sarcoma pattern with Leishmania parasitic colonization.

AIDS-Related Opportunistic Infections↗

[Chylothorax as presenting form of a gastric adenocarcinoma].

Malignancies other than lymphoma can in rare instances induce the development of chylothorax. A patient with this unusual type of pleural effusion is described herein. The need to rule out a gastric neoplasm when confronted with a case of chylothorax with no obvious cause is stressed.

Adenocarcinoma↗