SYNTHESIS OF DERMORPHINS,A NEW CLASS OF OPIATE-LIKE PEPTIDES

H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH₂ (dermorphin) and H-Tyr-D-Ala-Phe-Gly-Tyr-Hyp-Ser-NH₂ (Hyp⁶-dermorphin) are two members of a new class of opiatelike peptides present in the amphibian skin. Their syntheses and that of the L-Ala²-analogue of dermorphin have been accomplished by conventional segment condensation in solution.     

Follow-Up of a Respiratory Rate Modulated Pacemaker

The efficacy of 27 respiration sensitive rate modulated pacemakers (Biorate RDP-3 Biotec) implanted in the left pectoral area was evaluated every 3 months during a mean follow-up period of 29 months (range 10-50 months). Rate modulation function was unchanged other than for three patients in whom the auxiliary leads became displaced. Two implants lost ventricular sensing in this nonprogrammable model. In all but the three patients, Holter monitoring demonstrated pacing rate variation corresponding to daily activity. Stress test duration increased from 8.2 +/- 1.5 minutes (in fixed rate VVI rate) to 12.83 +/- 2.0 minutes (in the VVIR mode) (P less than 0.05). Right arm movement increased the pacing rate by 5 +/- 3 beats/min (NS), while the left arm movement increase was 30 +/- 5 beats/min (P less than 0.05). Mental, arithmetic, and nifedipine tests did not change the rate modulated pacing rate. The system responded to a change in respiratory rate by an increase in stimulation rate. A satisfactory response in sensitivity and velocity was present only with medium-high workloads. Interference with rate modulation occurred with movement of the arm ipsilateral to the implanted pulse generator.     

Annular Enlargement During Aortic Valve Replacement: Preliminary Results with a Simplified Technique

A simplified technique has been used to enlarge the aortic annulus in a series of 13 patients undergoing aortic valve replacement. The procedure basically consists of extending the aortotomy incision into the aortic annulus by dividing the commissure between the left and noncoronary sinuses, without involving the anterior mitral leaflet. Wide opening of the commissure is obtained and the resulting defect is closed, preferably using a patch of bovine pericardium sutured to the mitral annulus and aortic wall. This technique is simple, reproducible, avoids opening of the left atrium (reducing the potential bleeding sites), allows insertion of a prosthesis at least two sizes larger than the original annulus, and is also applicable in cases of mitral-aortic valve replacement. Our preliminary results are satisfactory and seem to demonstrate that in many patients, even in the young age group, more complex procedures are often unnecessary when enlargement of the aortic annulus is required.     

Actual Pacemaker Longevity: The Benefit of Stimulation by Automatic Capture Verification

Background: We evaluated the impact of an algorithm for automatic right ventricular (RV) stimulation compared to fixed‐output pacing (FOP) stimulation on actual pacemaker longevity over a 9‐year follow‐up. Methods: Prospective observation of 300 patients implanted with VDDR/DDDR pacemakers in 1999–2000 up to October 31, 2008. Sixty‐one patients were paced by Autocapture? pacing (ACP), 239 were paced by FOP; they were seen twice yearly at the pacemaker clinic. Factors known to affect pacemaker longevity were collected: median heart rate, %A&V paced activity, pacing output, and impedance. Patients dead before pacemaker replacement, lost to follow‐up, or who developed permanent atrial fibrillation were excluded from analysis. Results: One hundred twenty‐six of three hundred patients completed the study. Adverse clinical events due to an increased RV threshold occurred in two FOP patients compared to none among ACP. Pacemaker replacement occurred in 1/34 ACP patients versus 60/92 FOP patients (P < 0.001). ACP was the single independent predictor of pacemaker longevity at multivariable analysis (hazard ratio = 0.03, P < 0.001) either in the overall population or in the specific patients subgroups (sick sinus syndrome, atrioventricular block, and neurally mediated syncope). Conclusions: Automatic verification of stimulation is reliable at long term, and warrants superior safety in the event of pacing threshold changes. It allows a significant longevity increase compared to FOP stimulation that may heavily impact the patients’ quality of life and the cost of pacing therapy. Moreover, it is a fundamental technology in a strategy of remote patient and device monitoring, and may enable automatic device follow‐up operated by trained, nonmedical personnel. (PACE 2010; 873–881)     

Increase in liver pigmentation during natural hibernation in some amphibians

The amount/distribution of liver melanin in 3 amphibian species ( Rana esculenta , Triturus a. apuanus , Triturus carnifex ) was studied during 2 periods of the annual cycle (summer activity–winter hibernation) by light and electron microscopy, image analysis and microspectrofluorometry. The increase in liver pigmentation (melanin content) during winter appeared to be correlated with morphological and functional modifications in the hepatocytes, which at this period were characterised by a decrease in metabolic activity. These findings were interpreted according to the functional role (e.g. phagocytosis, cytotoxic substance inactivation) played by the pigment cell component in the general physiology of the heterothermic vertebrate liver and, in particular, in relation to a compensatory engagement of these cells against hepatocellular hypoactivity during the winter period.     

Randomized Clinical Trial on Short‐Time Compression with Kaolin‐Filled Pad: A New Strategy to Avoid Early Bleeding and Subacute Radial Artery Occlusion after Percutaneous Coronary Intervention

Background: Despite the increasing use of transradial techniques for cardiac percutaneous procedures, none of the strategies commonly utilized for hemostasis has been able to reduce the occurrence of radial artery occlusion (RAO). The aim of this study was to evaluate the occurrence of 24‐hour RAO and the rate of bleeding of a novel hemostatic device for radial closure after percutaneous interventions, in adjunct to short‐time compression. Methods: Once the radial access was obtained, patients were randomized to 3 different strategies of radial closure: a short compression with the QuikClot® Interventional? pad (Z‐Medica Corporation, Wallingford, CT, USA) (15 minutes, group 1), a short compression (15 minutes, group 2), and a conventional prolonged compression (2 hours, group 3) both without QuikClot® utilization. Results: Fifty patients in group 1, 20 in group 2, and 50 in group 3 were enrolled. The three groups were homogenous for baseline and procedural characteristics. None of patients in group 1 developed RAO, 1 (5%) occurred in group 2, and 5 (10%) in group 3 (P = 0.05). Active bleeding after compression removal occurred in 10 patients (20%) in group 1, 18 (90%) in group 2, and 1 (2%) in group 3 (P < 0.001). Among patients in group 1, at univariate analysis, the predictors of acute bleeding resulted in chronic therapy with clopidogrel (Odds Ratio 28.78, 95% Confidence Intervals 4.79–172.82, P < 0.001) and high levels of activated clotting time (ACT) at the time of sheath removal (OR 1.02, 95% CI 1.00–1.03, P = 0.009). At ROC analysis, the cutoff value of ACT for the risk of bleeding with a sensitivity of 80% and specificity of 75% was 287 seconds. Conclusions: Early sheet removal and short‐time compression with QuikClot® Interventional? can reduce the rate of RAO after diagnostic or interventional procedures especially in patients not on double antiplatelet therapy. (J Interven Cardiol 2011;24:65–72)     

Successful Double Percutaneous Alcohol and Coil Embolization of Bilateral Coronary-to-Pulmonary Artery Fistulas

We report the case of a 70-year-old man with recent myocardial infarction who was admitted for further evaluation of his effort angina. Cardiac catheterization and selective coronary angiography excluded significant coronary atherosclerotic disease of the coronary arteries. Double coronary-to-pulmonary artery fistulas, one originating from the proximal right, the other from the left anterior descending coronary arteries, and draining into the right and left branch of the pulmonary artery, respectively, were observed. A left-to-right shunt was visualized at angiography. The patient was successfully treated with percutaneous alcohol and coil embolization of both coronary artery fistulas with total resolution of clinical symptoms. At 6-month follow-up a coronary angiography confirmed complete disappearance of the fistulas. We conclude that a "coronary steal" phenomenon caused by the fistulas induced myocardial ischemia in this patient and that percutaneous transcatheter exclusion with chemical and mechanical devices is a safe. effective, and reasonable alternative to traditional cardiac surgery.