Search PubMed⌕ Search

Biomedical subjects

J Marco

Publications and source records attributed to J Marco.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Optimization of coronary angiographic views. Qualitative and quantitative evaluation of a new system].

A coronary angiographic view is said to be "optimal" when the directing radius of the X-ray beam is perpendicular to the long axis of a stenosis. The object was to fulfill two criteria: 1) the accurate calculation of the spatial orientation of the stenosis to obtain the optimal position, 2) rapid and optimal positioning of the angiographic material with easy rotation around the axis of the stenosis. Two combined solutions were proposed:the Advantx L/C (GE Medical systems) angiocardiographic system with three motorised axes of rotation and a specific software. This software takes into account two longitudinal axes of the stenosis traced by the operator in two conventional incidences and then determines the angles of optimal positioning (accuracy +/-5 degrees). During 97 consecutive coronary angiograms, the software was used in 23 cases (24%) and judged to be useful in 16 cases (70%). In 2 of the 23 cases (8%) the mechanical angles calculated could not be used, the incidences being incompatible with the patient's position. During the angiograms, the best two images of stenosis (one conventional, one optimal) were retained to form a pair of images. Eight observers analysed 37 pairs of images shown side by side. 65% of the images selected from each pair as being the best descriptive appearance of the stenosis came from the optimised system. During quantitative analysis, only the length of stenosis differed statistically between the two modes of acquisition (1.26 +/- 0.36 mm; p = 0.0014). This system is useful during coronary angiography for providing optimal views of stenosis free from any geometric distorsion and without superimposition of adjacent branches.

Coronary Angiography↗
PubMed1995

Comparison of in-hospital outcome in men versus women treated by either thrombolytic therapy or primary coronary angioplasty for acute myocardial infarction.

At 12 centers, 395 patients, including 288 men (73%) and 107 women (27%) with acute myocardial infarction (AMI), were prospectively randomized to treatment with tissue plasminogen activator (t-PA) or primary percutaneous transluminal coronary angioplasty (PTCA). Compared with men, women were older (65.7 vs 57.7 years, p < 0.0001), more often had diabetes mellitus (19% vs 10%, p = 0.03), systemic hypertension (54% vs 39%, p = 0.005), prior congestive heart failure (5% vs 0%, p = 0.002), and presented later after symptom onset (229 vs 174 minutes, p = 0.0004). The in-hospital mortality in women was 3.3-fold higher than men (9.3% vs 2.8%, p = 0.005). After adjustment for comorbid baseline characteristics, however, only advanced age independently correlated with mortality. Among t-PA-treated patients, mortality was significantly higher in women than in men (14.0% vs 3.5%, p = 0.006). Intracranial hemorrhage after t-PA was also more common in women than in men (5.3% vs 0.7%, p = 0.037). In contrast, women and men had similar in-hospital mortality after primary PTCA (4.0% vs 2.1%, respectively, p = 0.46). No intracranial bleeding occurred in PTCA-treated patients. A univariate trend was present for reduced in-hospital mortality in women treated with PTCA rather than t-PA (4.0% vs 14.0%, p = 0.07). By multiple logistic regression analysis of 15 clinical variables, treatment with PTCA rather than t-PA, as well as younger age, were independently predictive of in-hospital survival in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Predictors of in-hospital and 6-month outcome after acute myocardial infarction in the reperfusion era: the Primary Angioplasty in Myocardial Infarction (PAMI) trail.

OBJECTIVES: This study examined the predictors of in-hospital and 6-month outcome after different reperfusion strategies in acute myocardial infarction. BACKGROUND: Thrombolytic therapy and primary angioplasty are both widely applied as reperfusion modalities in patients with myocardial infarction. Although it is accepted that restoration of early patency of the infarct-related artery can reduce mortality and salvage myocardium, the optimal reperfusion strategy remains controversial, and the predictors of outcome in the reperfusion era have been incompletely characterized. METHODS: At 12 centers, 395 patients presenting within 12 h of onset of acute transmural myocardial infarction were prospectively randomized to receive tissue-type plasminogen activator (t-PA) or undergo primary angioplasty without antecedent thrombolysis. Sixteen clinical variables were examined with univariate and multiple logistic regression analysis to identify the predictors of clinical outcome. RESULTS: By univariate analysis, in-hospital mortality was increased in the elderly, women, patients with diabetes and in patients treated with t-PA as opposed to angioplasty. Only advanced age and treatment by t-PA versus angioplasty independently correlated with increased in-hospital mortality (6.5% vs. 2.6%, respectively, p = 0.039 by multiple logistic regression analysis). Similarly, the only variables independently related to in-hospital death or nonfatal reinfarction were advanced age and treatment by t-PA versus angioplasty (12.0% vs. 5.1%, p = 0.02). The reduction in in-hospital death or reinfarction with angioplasty versus t-PA was particularly marked in patients > or = 65 years of age (8.6% vs. 20.0%, p = 0.048). Furthermore, primary management with angioplasty versus t-PA was the most powerful multivariate correlate of freedom from recurrent ischemic events (10.3% vs. 28.0%, p = 0.0001). The independent beneficial effect of angioplasty on freedom from death or reinfarction was maintained at 6-month follow-up (8.2% vs. 17.0%, p = 0.02). CONCLUSIONS: In the reperfusion era, the two most powerful determinants of freedom from death, reinfarction and recurrent ischemia after myocardial infarction are young age and treatment by primary angioplasty.

Age Factors↗
PubMed1995

Implications of recurrent ischemia after reperfusion therapy in acute myocardial infarction: a comparison of thrombolytic therapy and primary angioplasty.

OBJECTIVES: The purpose of this study was to examine the incidence and implications of recurrent ischemia after different reperfusion strategies in acute myocardial infarction. BACKGROUND: The rates and effects of recurrent ischemia after reperfusion with thrombolytic therapy and with primary percutaneous transluminal coronary angioplasty have not been compared. METHODS: At 12 centers 395 patients presenting within 12 h of the onset of acute myocardial infarction were prospectively randomized to receive recombinant tissue-type plasminogen activator (rt-PA) or primary coronary angioplasty. Sixteen clinical variables were examined by using univariate and multiple logistic regression analysis to identify the predictors of recurrent ischemia. The relation of recurrent ischemic events to patient outcome was analyzed. RESULTS: Recurrent ischemia developed in 76 patients (19.2%) before hospital discharge, resulting in reinfarction in 18 patients (4.6%) and death in 5 (2.6%). Recurrent ischemia occurred in 56 patients (28.0%) after rt-PA but in only 20 patients (10.3%) after coronary angioplasty (p < 0.0001), directly contributing to a higher rate of death or reinfarction (7.5% vs. 3.1%, p = 0.05), catheterization and revascularization procedures and prolonged hospital stay after thrombolysis. By multivariate analysis, treatment with coronary angioplasty rather than rt-PA was the strongest predictor of freedom from recurrent ischemia. Although the incidence of recurrent ischemia after angioplasty and after rt-PA was similar within the 1st 2 days of admission (9.2% vs. 14.5%, p = 0.11), after hospital day 2 recurrent ischemia occurred in only 2 patients who received primary angioplasty compared with 27 patients who received rt-PA (1.1% vs. 13.5%, p < 0.0001). CONCLUSIONS: The development of recurrent ischemia adversely affects patient outcome, increasing morbidity, mortality and resource utilization. The much lower rate of recurrent ischemia after primary coronary angioplasty than after rt-PA results in improved survival without reinfarction and allows a shorter, less complicated hospital stay. Given the extremely low rate of recurrent ischemia after hospital day 2, safe early discharge on day 3 after primary coronary angioplasty should be feasible in selected patients with acute myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed1995

Distortion product otoacoustic emissions in healthy newborns: normative data.

Distortion product otoacoustic emissions (DPOAE) offer an alternative to transiently evoked otoacoustic emissions (TEOAE) as an audiological test. The former can be used as a screening technique, and may also provide frequency-specific information about the functional state of the cochlea. We recorded DPOAE in a group of healthy newborns to establish the characteristics of a DPOAE "audiogram" (DP-gram) in this population. The DP-gram can be obtained with characteristics quite similar to those observed in adults, with two sharp peaks of maximum amplitude at F2 frequencies of 2 kHz and 5-6 kHz, and a decline in DPOAE amplitude in midfrequencies. The results confirm the limitations of DPOAE recording for testing parts of the basilar membrane where lower frequencies are coded.

Acoustic Stimulation↗
PubMed1995

Inhibitory effect of amylin (islet amyloid polypeptide) on insulin response to non-glucose stimuli. Study in perfused rat pancreas.

Amylin, also called islet amyloid polypeptide (IAPP), can inhibit the glucose-induced insulin secretion in perfused rat pancreas at 75 pmol/l, a concentration comparable to that found in the effluent of this experimental model. To further explore the influence of amylin on insulin release, we investigated the effect of synthetic rat amylin (75 pmol/l) on insulin response to non-glucose secretagogues. These agents stimulate B-cell secretion via different mechanisms, such as a dihydropyridine derivative (BAY K 8644, 10 mmol/l) which activates Ca(2+)-channels, a sulfonylurea (tolbutamide, 0.2 mmol/l) which blocks ATP-dependent K(+)-channels, KCL (11 mmol/l) which depolarizes B cells and the 26-33 fragment of cholecystokinin (8-CCK, 1 nmol/l) which increases phospholipid turnover. The study was performed in perfused rat pancreas. Amylin significantly inhibited insulin response to BAY K 8644 (65%), KCI (60%) and 8-CCK (80%) as well as the early phase of tolbutamide-induced insulin output (70%). Thus, amylin can inhibit insulin release induced by secretagogues that interact at different levels of B-cell stimulus-secretion coupling. This inhibition may be due to a multifarious influence of amylin on the B-cell secretory mechanism and/or a disturbing effect on a distal, crucial step in the insulin-releasing mechanism, e.g. by affecting exocytosis of the secretory granule or by inhibiting an essential metabolic pathway within the B cell.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1994

Brucella ovis infection in two flocks of sheep.

Brucella ovis infection could not be eradicated from two flocks of sheep despite serologically testing and culling the infected rams for four years. The hypothesis that the ewes played a major role in the maintenance of the infection in both flocks was investigated by using serological, bacteriological and pathological criteria. Specific antibodies against B ovis were demonstrated in 71 ewes in the two flocks. Forty-four of the seropositive ewes were slaughtered for bacteriological and pathological studies and B ovis was isolated from 16 of them; the uterus was the target organ of the infection, although extrauterine infection was also demonstrated in some of the infected ewes.

Animals↗
PubMed1994

A comparison of balloon-expandable-stent implantation with balloon angioplasty in patients with coronary artery disease. Benestent Study Group.

BACKGROUND: Balloon-expandable coronary-artery stents were developed to prevent coronary restenosis after coronary angioplasty. These devices hold coronary vessels open at sites that have been dilated. However, it is unknown whether stenting improves long-term angiographic and clinical outcomes as compared with standard balloon angioplasty. METHODS: A total of 520 patients with stable angina and a single coronary-artery lesion were randomly assigned to either stent implantation (262 patients) or standard balloon angioplasty (258 patients). The primary clinical end points were death, the occurrence of a cerebrovascular accident, myocardial infarction, the need for coronary-artery bypass surgery, or a second percutaneous intervention involving the previously treated lesion, either at the time of the initial procedure or during the subsequent seven months. The primary angiographic end point was the minimal luminal diameter at follow-up, as determined by quantitative coronary angiography. RESULTS: After exclusions, 52 patients in the stent group (20 percent) and 76 patients in the angioplasty group (30 percent) reached a primary clinical end point (relative risk, 0.68; 95 percent confidence interval, 0.50 to 0.92; P = 0.02). The difference in clinical-event rates was explained mainly by a reduced need for a second coronary angioplasty in the stent group (relative risk, 0.58; 95 percent confidence interval, 0.40 to 0.85; P = 0.005). The mean (+/- SD) minimal luminal diameters immediately after the procedure were 2.48 +/- 0.39 mm in the stent group and 2.05 +/- 0.33 mm in the angioplasty group; at follow-up, the diameters were 1.82 +/- 0.64 mm in the stent group and 1.73 +/- 0.55 mm in the angioplasty group (P = 0.09), which correspond to rates of restenosis (diameter of stenosis, > or = 50 percent) of 22 and 32 percent, respectively (P = 0.02). Peripheral vascular complications necessitating surgery, blood transfusion, or both were more frequent after stenting than after balloon angioplasty (13.5 vs. 3.1 percent, P < 0.001). The mean hospital stay was significantly longer in the stent group than in the angioplasty group (8.5 vs. 3.1 days, P < 0.001). CONCLUSIONS: Over seven months of follow-up, the clinical and angiographic outcomes were better in patients who received a stent than in those who received standard coronary angioplasty. However, this benefit was achieved at the cost of a significantly higher risk of vascular complications at the access site and a longer hospital stay.

Angina Pectoris↗
PubMed1994

Amylin (islet amyloid polypeptide) inhibition of insulin release in the perfused rat pancreas: implication of the adenylate cyclase/cAMP system.

Amylin inhibits glucose-induced insulin secretion in the rat pancreas. To study the mechanism by which amylin acts on the B-cell, we have investigated, in the perfused rat pancreas, the effect of synthetic rat amylin (75 pM) on insulin release elicited by secretagogues acting on the B-cell via the adenylate cyclase/cAMP system, i.e., glucagon (10 nM), gastric inhibitory polypeptide (GIP, 1 nM), forskolin (1 microM) and isobutylmethylxanthine (IBMX, 75 microM). In addition, we examined the effect of amylin on GIP-induced insulin release in pancreata from rats pretreated with pertussis toxin, an agent which inactivates certain Gi proteins coupled to adenylate cyclase. Amylin inhibited the insulin response to glucagon (approx. 70%), GIP (approx. 90%), IBMX (approx. 75%) as well as the early phase of forskolin-induced insulin output (approx. 74%). However, amylin failed to modify GIP-induced insulin release in pancreata obtained from pertussis toxin pretreated rats. These results would indicate that the inhibitory effect of amylin on insulin secretion could be, at least in part, attributed to its interfering with the adenylate cyclase/cAMP system. Furthermore, prevention of the inhibitory effect of amylin on GIP-induced insulin output by pertussis toxin pretreatment, supports the concept that amylin can inhibit insulin release via a pertussis toxin-sensitive Gi protein coupled to the adenylate cyclase system.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Coronary vasoconstriction after percutaneous transluminal coronary angioplasty is attenuated by antiadrenergic agents.

BACKGROUND: Vasoconstriction occurs after percutaneous transluminal coronary angioplasty (PTCA) along the dilated vessel. The vasomotor changes, initiated by the mechanical stretch of the stenotic region, are thought to be due to various mechanisms but whether the sympathetic nervous system plays a role in this phenomenon remains unknown. METHODS AND RESULTS: Quantitative angiography (ARTREK) was performed in 45 patients undergoing an epicardial vessel PTCA for a stenosis of 76 +/- 1% (1) in basal conditions, (2) after PTCA, and (3) 30 minutes after PTCA (vasoconstriction). In 14 control patients, the same measurements were obtained up to 60 minutes after PTCA. Coronary diameters were measured along the PTCA vessel at the narrowest stenosis level and at a level peripheral to stenosis. In 36 patients two diameters were also measured at a proximal segment and at a distal segment along a nonmanipulated vessel. Thirty minutes after PTCA the dilated segment underwent a -31 +/- 2% (mean +/- SEM, ANOVA, P < .05) reduction in diameter when compared with PTCA values, and the segment peripheral to stenosis showed a reduction of -17 +/- 2% (P < .05). In all patients a significant vasoconstriction also was observed along the control vessel (proximal segment, -14 +/- 3%; P < .05 versus basal; and distal segment, -17 +/- 2%). At the time of maximal vasoconstriction (30 minutes after PTCA), the patients (treatment groups) received (1) 18 micrograms/kg IC phentolamine (Phe, n = 7), (2) 14 micrograms/kg IC yohimbine (YO, n = 7), (3) 16 micrograms/kg IC propranolol (Pro) followed by 18 micrograms/kg IC phentolamine (Pro+Phe, n = 7), and (4) 0.2 mg/kg IC bretylium (Bre, n = 10). In 14 patients (control groups) an intracoronary injection of warm saline was given. After drug injections, angiograms were repeated at 5-minute intervals for 20 minutes and ended after a 300-micrograms intracoronary trinitroglycerin injection. At stenosis level, Phe and Bre counteracted vasoconstriction, inducing a dilatation of +19 +/- 3% and +22 +/- 6%, respectively, while Pro+Phe caused a dilatation of +16 +/- 9% above the PTCA values (P < .05 versus PTCA). YO only partially reversed vasoconstriction (from -33 +/- 4% to -12 +/- 4%, P = NS versus PTCA). At peripheral-to-stenosis level, vasoconstriction was abolished by Phe (+26 +/- 7%, P < .05 versus basal), while it was still present after Pro+Phe (-23 +/- 2%) and Bre (-18 +/- 4%). In addition, Phe and Bre dilated the control vessel at the proximal segment (+17 +/- 6% and +8 +/- 4%, respectively, P < .05 versus basal), while YO and Pro+Phe only counteracted vasoconstriction (from -15 +/- 3% to +7.6 +/- 1% and from -16 +/- 3% to +4 +/- 5%, respectively, P = NS versus basal). At the distal segment only Phe produced a vasodilatation of +23 +/- 1%; YO counteracted constriction (from -16 +/- 2% to +9 +/- 6%, P < .05 versus basal), whereas after Pro+Phe and Bre, the vasoconstriction persisted. CONCLUSIONS: The mechanical stretch and ischemia caused by balloon inflation induced vasoconstriction mediated by alpha-adrenergic receptors (mainly alpha 1), overcoming a beta-mediated dilatation. The use of different antiadrenergic drugs showed that Phe counteracts post-PTCA vasoconstriction, and the simultaneous use of alpha- and beta-receptor blocking agents (Pro+Phe and Bre) reveals the presence of a peripheral, predominant beta-mediated dilatation. The presence of vasoconstriction also along the control vessels not branching from the stretched ramus provides evidence for the existence of neural sympathetic vasoconstrictor reflexes.

Angioplasty, Balloon, Coronary↗
PubMed1994

[The short-term results and angiographic predictors of subacute thrombosis in the coronary implantation of the Palmaz-Schatz endoprosthesis].

INTRODUCTION AND OBJECTIVES: Intracoronary stenting has been proposed as an adjunct to balloon angioplasty in order to improve the immediate and long-term results. The purpose of this study was evaluate the short-term results, subacute closure rate and to try to identify angiographic predictors of subacute thrombotic after Palmaz-Schatz stent implantation. METHODS: Through a prospective registry, we have evaluated in 500 patients the safety and efficacy of Palmaz-Schatz stent implantation (580 in total) in coronary arteries and saphenous vein grafts. The identification of clinic and angiographic predictors of subacute closure have been evaluated with the assistance of a BMDP statistical software using an univariate and multivariate statistical analysis (logistic regression). The determination of diameter and stenosis has been achieved by electronic caliper. RESULTS: The stent was implanted successfully in 98.6% of the patients. There was no abrupt closure (< or = 1 day), however 36 patients (7.2%) developed subacute thrombotic closure (among 2nd-21st day after stenting). The major complications were: death 9 patients (1.8%), bypass surgery 7 patients (1.4%) and myocardial infarction 21 patients (4.2%). The predictors of subacute thrombotic closure through univariate statistical were: stenting for bail-out (S.T.: 27%; p < or = 0.0001), multiple stenting (S.T.: 24.1%; p < or = 0.0001), final diameter stent < or = 3.25 mm (S.T.: 12.6%; p < or = 0.013), and left ventricular ejection fraction < or = 45% (S.T.: 15.7%; p < or = 0.022). We showed with logistic regression that final diameter stent < or = 3.25 mm; p < or = 0.0030, left ventricular ejection fraction < or = 45%; p < or = 0.0012, stenting for bail-out; p < or = 0.0195 and multiple stenting; p < or = 0.0252, were predictors of subacute thrombotic closure. CONCLUSIONS: The Palmaz-Schatz coronary stenting will preferably realize in those arteries bigger than 3.25 mm and left ventricular ejection fraction > 45%, showing multiple stenting and stenting for bail-out greater subacute thrombotic closure rate.

Acute Disease↗
PubMed1994

Opioids and the pulsatile prolactin secretory pattern: effects of hyperprolactinemia.

It is well known that opioids regulate prolactin secretion through unknown mechanisms. The present study describes the effects of morphine and naloxone administration on pulsatile prolactin secretion in adult sham-operated and pituitary-grafted female rats. Animals were rendered hyperprolactinemic by transplanting 2 pituitary glands beneath the kidney capsule. Naloxone (2 mg/kg/h), morphine (50 mg/kg/h)+naloxone or saline (0.5 ml/h) were administered i.v. through a jugular cannula and bled at 7-min intervals for a period of 3 h. Pituitary grafting increased mean serum prolactin levels, the absolute amplitude and the duration of the pulses, but decreased their frequency. Naloxone, in sham-operated rats, reduced mean serum prolactin levels, the absolute amplitude and the frequency of the pulses. However, morphine+naloxone administration increased mean serum prolactin levels and the absolute amplitudes of prolactin pulses in pituitary-grafted rats. Naloxone administration did not decrease previously increased mean serum levels of prolactin in pituitary-grafted rats. These results suggest that opioids synchronize the pulsatile pattern of prolactin and that these effects are blunted in pituitary-grafted animals.

Animals↗
PubMed1994

Effects of naloxone on pulsatile luteinizing hormone in experimental hyperprolactinemia.

It is well known that opioids regulate luteinizing hormone (LH) secretion through not fully understood mechanisms. This study describes the effects of naloxone on the episodic release of LH in adult sham-operated and pituitary-grafted female rats. Animals were rendered hyperprolactinemic by transplanting 2 pituitary glands beneath the kidney capsule. Naloxone (2 mg/kg/h) or saline (0.5 ml/h) were administered iv through jugular cannulae and subjects were bled at 7 min intervals for a period of 3 h. As expected, pituitary-grafting was followed by an increase in mean values of prolactin during the bleeding period. Naloxone administration decreased mean serum prolactin levels in sham-operated rats and did not further change them in pituitary-grafted animals. Hyperprolactinemia was associated with increases in mean serum LH levels during the bleeding period and in the absolute amplitude of LH peaks. Naloxone administration increased mean values of LH and the absolute amplitude of LH peaks, and decreased their frequency in sham-operated rats. Neither pituitary grafting nor naloxone administration modified the frequency, duration or relative amplitude of LH peaks. However, naloxone administration reduced the mean half-life of LH in sham-operated rats to a similar extent than did pituitary grafting. Naloxone failed to further change the mean half-life of LH in pituitary-grafted rats. These results suggest that opioids modulate the pulsatile pattern of LH and that these effects are blunted in pituitary-grafted animals.

Analysis of Variance↗
PubMed1993

Reversal of the inhibitory effects of calcitonin gene-related peptide (CGRP) and amylin on insulin secretion by the 8-37 fragment of human CGRP.

The 8-37 fragment of human calcitonin gene-related peptide [(8-37)hCGRP] antagonizes the effects of calcitonin gene-related peptide (CGRP) and amylin in a number of tissues. We have studied the influence of (8-37)hCGRP on the effects of both CGRP and amylin on insulin secretion. In the perfused rat pancreas, homologous CGRP and amylin, at 75 pM, exerted comparable inhibitory effects on the insulin response to 9 mM glucose (ca. 70%; P < 0.025). These effects were antagonized by (8-37)hCGRP (1 microM). Our results suggest that CGRP and amylin act on the B-cell, at least in part, through a common receptor.

Amyloid↗
PubMed1993

A comparison of immediate angioplasty with thrombolytic therapy for acute myocardial infarction. The Primary Angioplasty in Myocardial Infarction Study Group.

BACKGROUND: The success of thrombolytic therapy for acute myocardial infarction is limited by bleeding complications, the impossibility of reperfusing all occluded coronary arteries, recurrent myocardial ischemia, and the relatively small number of patients who are appropriate candidates for this therapy. We hypothesized that these problems could be overcome by the use of immediate percutaneous transluminal coronary angioplasty (PTCA), without previous thrombolytic therapy. METHODS: At 12 clinical centers, 395 patients who presented within 12 hours of the onset of myocardial infarction were treated with intravenous heparin and aspirin and then randomly assigned to undergo immediate PTCA (without previous thrombolytic therapy, 195 patients) or to receive intravenous tissue plasminogen activator (t-PA, 200 patients) followed by conservative care. Radionuclide ventriculography was performed to assess ventricular function within 24 hours and at six weeks. RESULTS: Among the patients randomly assigned to PTCA, 90 percent underwent the procedure; the success rate was 97 percent, and no patient required emergency coronary-artery bypass surgery. The in-hospital mortality rates in the t-PA and PTCA groups were 6.5 and 2.6 percent, respectively (P = 0.06). In a post hoc analysis, the mortality rates in the subgroups classified as "not low risk" were 10.4 and 2.0 percent, respectively (P = 0.01). Reinfarction or death in the hospital occurred in 12.0 percent of the patients treated with t-PA and 5.1 percent of those treated with PTCA (P = 0.02). Intracranial bleeding occurred more frequently among patients who received t-PA than among those who underwent PTCA (2.0 vs. 0 percent, P = 0.05). The mean (+/- SD) ejection fractions at rest (53 +/- 13 vs. 53 +/- 13 percent) and during exercise (56 +/- 13 vs. 56 +/- 14 percent) were similar in the t-PA and PTCA groups at six weeks. By six months, reinfarction or death had occurred in 32 patients who received t-PA (16.8 percent) and 16 treated with PTCA (8.5 percent, P = 0.02). CONCLUSIONS: As compared with t-PA therapy for acute myocardial infarction, immediate PTCA reduced the combined occurrence of nonfatal reinfarction or death, was associated with a lower rate of intracranial hemorrhage, and resulted in similar left ventricular systolic function.

Adult↗
PubMed1993

Amylin inhibits glucose-induced insulin secretion in a dose-dependent manner. Study in the perfused rat pancreas.

Islet amyloid polypeptide (IAPP), also called amylin, has been localized in the B-cell secretory granule and is co-secreted with insulin. We have investigated the effect of synthetic amidated rat amylin on the insulin release evoked by 9 mM glucose in the isolated, perfused rat pancreas. Amylin, in a range of 75 nM-75 pM, significantly inhibited this insulin response in a dose-dependent manner. The correlation between the logarithm of amylin concentrations and the percentages of inhibition was highly significant (r = 0.98, P < 0.01). The lowest effective amylin concentration tested (75 pM) is within the range of amylin levels reported for the effluent of the perfused rat pancreas. Finally, pre-infusion of the rat pancreas with a high amylin concentration (75 nM) did not alter the insulin response to glucose, thus excluding a toxic effect of amylin on the B-cell. These observations support the concept that amylin plays a role in the control of insulin secretion.

Amyloid↗