P412 SCAD: A PLANET TO DISCOVER IN THE UNIVERSE OF ACS

We hereby present the case of a 36–year–old woman with neither a history of cardiovascular disease nor any cardiovascular risk factors. Her only past medical history included a pregnancy from in vitro fertilization and endometriosis treated with progestin. She was admitted to A&E for sudden onset severe stabbing thoracic pain, which occurred at rest and was exacerbated by respiratory efforts, and with spontaneous resolution shortly after admission. While the ECG did not show any signs of ischemic, blood tests revealed a minor rise in inflammatory markers and a significant rise in troponin values, the latter consistent with acute myocardial injury.

Given the clinical suspicion of myopericarditis vs acute coronary syndrome, the patient was admitted to cardiac intensive care unit. Bedside echocardiogram performed shortly after admission demonstrated minor pericardial effusion and regional wall motion abnormalities. Thus, the patient underwent urgent coronary angiography, which revealed pronounced vasospasm at the proximal segment of the circumflex artery, which subsided after administration of nitrate, as well as spontaneous dissection of the mid left anterior descending artery extending to its apical branch. Since no high–risk features were identified (single vessel, mid–distal coronary lesion, no symptoms of persistent ischemia), revascularisation was not attempted and conservative therapy was undertaken. During the following days, genetic evaluation and further diagnostic tests were performed to exclude vascular abnormalities in other anatomical sites, which all resulted negative. Outpatient follow–up with CT coronary angiogram demonstrated full patency of left anterior descending artery with spontaneous resolution of the former dissection.

This clinical scenario represents an example of an uncommon and thus often overlooked cause of acute coronary syndrome with yet limited evidence on optimal therapeutic and follow–up strategies.

P157 THE UNFORESEEABLE LINK: A CASE OF CORONARY–PULMONARY ARTERY FISTULA BRIDGING THE RIGHT CORONARY AND FIRST SEPTAL BRANCH OF THE LEFT ANTERIOR DESCENDING ARTERY

Coronary–pulmonary artery fistulas are a rare clinical entity with a variety of potential clinical manifestations. Albeit rare, such anomalies may in some instances involve multiple coronary arteries and go unnoticed until old age producing little to no clinical manifestations. We hereby present the case of an 83–year–old man, heavy smoker, with a history of cor pulmonale due to severe chronic obstructive pulmonary disease (COPD) who was recently diagnosed with metastatic lung adenocarcinoma. Incidentally, one of the ECGs performed revealed negative T waves in the precordial leads in the absence of symptoms and with a negative troponin curve. Echocardiography was thus performed and revealed severe left ventricular systolic dysfunction (EF 31%) with infero–postero–lateral akinesia. The patient underwent CT coronary angiogram, which ruled out any significant coronary stenosis but revealed a most surprising finding. An ectatic arterial branch running anteriorly and draining into the pulmonary artery connected the the proximal segment of the right coronary artery to the first septal branch of the left anterior descending (LAD) artery. Unfortunately, the severe left ventricular failure contraindicated any chemotherapy and the patient was discharged with a plan to start palliative radiotherapy. Three months later, the patient returned to our Hospital due to worsening weakness, cachexia and one episode of pre–sincope. During this hospital stay, he developed atypical chest pain with a significant troponin curve. A HRCT and pulmonary angiogram was performed, which revealed neoplastic progression with bilateral lung involvement and bone metastases, as well as bilateral segmental pulmonary emboli. Echocardiography demonstrated new segmental areas of akinesia (apical septum and mid–apical anteroseptal segment) suggestive of focal ischemic damage. Given the documented pulmonary embolism and the anomalous connection between pulmonary artery and coronary circulation, this event may have been caused by paradoxical embolism travelling from pulmonary to coronary circulation (most likely affecting the LAD artery territory). Due to the patient’s frailty however, this hypothesis could not be confirmed by coronary angiography. Despite their relative rarity, coronary–pulmonary artery fistulas involving multiple coronary arteries can occur in the elderly population with no previous clinical manifestations and may give rise to apparently unfathomable clinical constellations.

P28 AN OMINOUS FINDING OF BRUGADA PATTERN: FROM PAROXYSMAL ATRIAL FIBRILLATION TO SEVERE TRICUSPID VALVE REGURGITATION

49 years old male, without family history of sudden cardiac death, subjected in 2010 to effective electrical cardioversion for a first episode of paroxysmal atrial fibrillation. In 2013, a new episode of atrial fibrillation subjected to effective pharmacological cardioversion with flecainide and contextual finding of intermittent Brugada type I pattern, confirmed by ajmaline provocation test. Considering the asymptomaticity of the patient and the negative family history of sudden cardiac death, no indication was given to defibrillator implantation. In 2015 the patient performed an Electrophysiological Study, positive for induction of ventricular fibrillation, in the light of which an ICD was implanted. In the following years regular checks of the device were performed, in absence of activations. In 2021, at the annual checkup, rupture of the leads was documented, resulting in a complete extraction and reimplantation of the device. A few days later the patient was admitted to the Emergency Room for chest pain and worsening dyspnea, signs of initial right heart failure and increased inflammatory markers. In consideration of the anamnestic history, the presence of infective endocarditis was suspected, for which the patient was admitted to the Cardiology ward. The echocardiogram showed severe tricuspid valve regurgitation due to complete flail of the septal flap and rupture of first order tendon cord, probably iatrogenic and consequent to the extraction of the leads. FDG–PET was performed, which ruled out the presence of infective endocarditis, and surgical correction of the valvulopathy and definitive ICD explant was indicated. The surgery consisted of plastic repair of the tricuspid valve, implantation of definitive epicardial bipolar electrodes, isolation of the pulmonary veins for atrial fibrillation ablation and removal of the ICD. Brugada syndrome, starting from the 2013 consensus, can be diagnosed in patients who only feature the type 1 pattern, spontaneous or pharmacologically induced, even in the absence of malignant arrhythmias or family history of sudden death. This leads as a consequence to an increase in the number of patients undergoing invasive procedures and interventions even with low arrhythmic risk, being instead susceptible to the complications that such procedures can fatally provoke.

Generalized thermodynamic and transport properties. I. Simple liquids

We propose a method by which the generalized transport properties and coefficients at all wavelengths and frequencies can be obtained by inversion of an exact kinetic equation. The necessary data are the density-density, energy-energy, and density-energy time correlation functions, which can be obtained by molecular-dynamics simulation. In addition, also the coupling between viscous stress tensor and energy flux vector can be obtained without approximation. This allows one to check the validity of the Markov assumption in a straightforward way. As a first test case, the theory is applied to liquid argon in two thermodynamic states. For this system, we calculate and discuss generalized thermodynamic (enthalpy, specific heats, and thermal expansion) and transport properties (longitudinal viscosity, thermal conductivity).

Generalized thermodynamic and transport properties. II. Molecular liquids

In the present paper, we extend the method described in paper I [D. Bertolini and A. Tani, preceding paper, Phys. Rev. E 83, 031201 (2011)] to molecular liquids, which allows us to solve the exact kinetic equation proposed by de Schepper et al. [Phys. Rev. A 38, 271 (1988)] without approximations. In particular, generalized thermodynamic properties (enthalpy, specific heat, and thermal expansion coefficient) and transport properties (longitudinal viscosity, thermal conductivity) have been calculated for three liquids of increasing complexity, namely dimethyl sulfoxide, hydrogen fluoride, and SPC/E water. All results have been obtained by the molecular formalism as well as the atomic one, corrected for intramolecular correlations that are due to the models adopted. As done for simple liquids, the coupling between the viscous stress tensor and the energy flux vector has been calculated exactly. We also show that the Markov assumption for the dynamics related to thermal conductivity can only be adopted with caution.

[Role of endoscopy in the management of obscure gastrointestinal bleeding]

Obscure gastrointestinal bleeding is defined as a blood loss in the digestive tract without etiology found at upper digestive endoscopy and colonoscopy. Small bowel lesions, in particular angiodysplasias, are the most frequent cause. Endoscopic examination of the small bowel can be performed using an enteroscope (with or without balloon) or a videocapsule. Videocapsule endoscopy is a minimally invasive procedure, and it allows complete small bowel exploration in 80% of cases (vs. 40-80% with balloon-aided enteroscopy). In practice, videocapsule endoscopy is the first line exam, followed by enteroscopy for biopsy sampling or treatment. In case of completely negative investigations and persistent bleeding, videocapsule endoscopy may be repeated, generally after repeat upper digestive endoscopy and colonoscopy.

[Functional bowel disorders: impact and limitations of evidence-based medicine]

Although tremendous efforts have been carried out to explore the physiopathology, classification and therapeutic modalities of functional bowels disorders, these conditions still elude the classical anatomical-clinical approach. This article summarizes recent advances in the field, discusses critically their impact on daily clinical practice and provides some practical recommendations.

Simultaneous micromechanical and electromagnetic detection of electron paramagnetic resonance

The peculiar advantages of simultaneous observation by electromagnetic and micromechanical methods in EPR spectroscopy are discussed. The development of a novel apparatus with the capability of this simultaneous detection is described. Experiments at 23 GHz show the performance of the apparatus. The problems related to the sensitivity and to the spatial resolution are analyzed. Future prospects are presented. Copyright 1999 Academic Press.

Molecular cloning and characterization of LR3, a novel LDL receptor family protein with mitogenic activity

We report molecular cloning and initial functional characterization of a novel member of the low density lipoprotein receptor (LDLR) gene family. The cDNA was isolated from a human osteoblast cDNA library and encoded a 1,615 amino acids protein designated as LR3. It has, in the extracellular region, a cluster of three LDLR ligand binding repeats at a juxtamembrane position and four EGF precursor homology domains separated by YWTD spacer repeats. The entire ectodomain shares the same modular organization with the middle portion of the extracellular regions of two LDLR family members, LDLR-related protein (LRP), and gp330/megalin. LR3 mRNA was expressed in most of the adult and fetal tissues examined. The highest expression level was seen in aorta. In human osteosarcoma cells examined, LR3 mRNA was highly enriched in TE85 cells, moderately expressed in MG63 cells and primary human osteoblasts, and undetectable in SaOS-2 cells. NIH 3T3 cells transfected with either full length LR3 or its ectodomain showed significantly increased proliferation, whereas transfection of intracellular domain had no proliferative effect. We predict that LR3 is a multi-functional protein with potential mitogenic activity.

Morphological and structural characteristics of the proximal femur in human and rat

Because the ovariectomized rat model of postmenopausal osteoporosis is the most commonly used small animal model to investigate consequences of bone loss on bone structure and strength, or to assess benefits of the various therapeutic strategies to improve bone mass and strength, the attempt was made to compare histoanatomical and structural characteristics of the femoral neck between human and rat models. In addition to different biomechanics, there is a significant difference in gross- and microanatomy of the proximal femur between humans and rats. Percent of the cortical bone component is much higher in rats (72.5%) relative to humans (12.5%). Also, cortical bone at the femoral neck in rats is evenly distributed, whereas in humans there is a considerable difference in the amount of the cortical bone between the superior half of the femoral neck with cortical thickness being only 0.3 mm, and the inferior half of the neck having 6-mm-thick cortex. Humans have far more cancellous bone at the femoral neck (22.7% average) relative to rats (6.8%). In addition, cancellous bone at the femoral neck in humans is unevenly distributed between the bone center and its periphery. Human samples exhibited striking differences in the cancellous bone structure between weight-bearing and tensile trabecular groups exhibiting clear trabecular orientation consisting of plates and rods, and trabeculae around the neutral bone axis with little mechanical activity exhibiting rod-like trabeculae only. Although humans and rats have a periosteum covering the femoral neck, and each lacks the muscular attachment at intracapsular portions of the femoral neck, rats, in contrast to humans, have the ability to quickly adapt cortical thickness and increase inertia to meet mechanical needs via modeling-dependent periosteal apposition.

Anti-arthritic activity of hydroxamic acid-based pseudopeptide inhibitors of matrix metalloproteinases and TNF alpha processing

OBJECTIVE AND DESIGN

The effects of two hydroxamate inhibitors of metalloproteinase and tumor necrosis factor alpha (TNF alpha) processing on endotoxin-induced plasma TNF alpha and arthritic lesions in adjuvant-induced arthritic (AA) rats were determined.

MATERIAL AND TREATMENT

BB-1101 and BB-1433 were administered orally twice daily to AA Lewis rats with an established disease (days 13 to 22). AA rats (day 16) or normal rats were injected with bacterial endotoxin and plasma levels of TNF alpha were also determined.

METHODS

Hindpaw swelling was measured plethysmographically. Bone degradation was determined by radiography and bone mineral densitometry. TNF alpha was quantified using a sandwich ELISA.

RESULTS

The hydroxamic-acid pseudopeptides inhibited plasma. TNF alpha levels in vivo and significantly reduced swelling and bone degradation of the tibiotarsal joints of AA rats in the range of 10-50 mg/kg given orally (p < 0.01 by Student's t-test).

CONCLUSIONS

Thus, these novel compounds offer a new disease modifying therapy for arthritis and the results also suggest that inhibition of TNF alpha production may contribute, at least in part, to their anti-arthritic activity.

Pharmacologic evaluation of the calcitonin analogue SB 205614 in models of osteoclastic bone resorption in vitro and in vivo: comparison with salmon calcitonin and elcatonin

The activity of a novel calcitonin SB 205614 was compared with salmon calcitonin (sCT) and (Asu1,7)-eel calcitonin (ELC) in six different models of osteoclastic bone resorption in vitro and in vivo. SB 205614 is an ELC analogue that has an acetylenic bridge instead of the natural disulphide bridge, rendering the molecule more stable biologically than sCT and equally stable to ELC. Our aim was to determine whether this structural change compromised biologic activity, and if not, whether the increased stability could be used to exploit novel modes of administration. In the in vitro assays of pit formation by disaggregated rat osteoclasts on cortical bone slices (DROcA) and PTH stimulation of 45Ca-release from prelabeled fetal rat bone, no significant differences in activity were observed between the three calcitonins. In the DROcA, IC50s of 0.003, 0.015 and 0.064 pg/ml for sCT, ELC, and SB 205614, respectively, were determined, with total or near complete inhibition observed at 1 pg/ml (0.3 pM). In the assay of PTH-stimulation of 45Ca release, IC50s were measured of 5.5, 4.8, and 12.9 pM for sCT, ELC, and SB 205614, respectively; in every case maximal inhibition (ca. 80%) was observed at 30 and 100 pM. The internationally approved U.S. Pharmacopoeia bioassay of hypocalcemia in the rat following intravenous (IV) administration indicated that SB 205614 had a greater potency than ELC or sCT. More important, a full dose-hypocalcemic response curve demonstrated significantly increased potency compared to sCT or ELC, as the doses causing 15% lowering of serum calcium (approximately 50% of the maximum effect) were 33.9, 25.2, and 12.9 mg/kg for sCT, ELC, and SB 205614, respectively. As a preliminary means of investigating alternative delivery forms of calcitonin, the time course of the hypocalcemic effect was investigated in the rat and rabbit following IV administration, and was compared with that following intranasal (IN) administration (rat and rabbit), and following intracolonic administration (rat only). Maximal effects were similar, whereas in general the hypocalcemic effect of SB 205614 was of a longer duration than the other two calcitonins; this was reflected in a larger area over the curve (AOC). However, following IN administration in the rabbit, where an aerosol delivery device similar to that used in the clinic was used to administer the calcitonins, SB 205614 (100 IU/kg) induced a highly significant two-fold increase in the AOC compared to ELC or sCT. The calcitonins were also compared in assays designed to measure therapeutic efficacy in the rat.(ABSTRACT TRUNCATED AT 400 WORDS)

Magnetic resonance microscopy in rat skeletal research

Noninvasive evaluation of skeletal tissue, particularly certain sites that tend to be predisposed to disease, is critical in understanding the pathogenesis, progression, and successful treatment of various diseases like osteoporosis, rheumatoid arthritis, and osteoarthritis. Although several noninvasive techniques are currently available to evaluate skeletal tissues, they all have critical limitations. We report here a systematic study to compare the morphological changes (overall profile and tissue architecture) in the proximal tibiae and coccygeal vertebrae of a young growing rat and an older retired female breeder rat using 2- and 3-dimensional MR (magnetic resonance) microscopy and histology. We have obtained MR microimages of intact rat tibiae and vertebrae with resolution upto 24 24 250 microns and have found excellent correlations between MR microscopy results and histological assessment.

IL-6 stimulates osteoclast-like multinucleated cell formation in long term human marrow cultures by inducing IL-1 release

IL-6 enhances the differentiation of pluripotent hematopoietic stem cells but predominantly affects the differentiation of hematopoietic cells in the granulocyte-macrophage lineage. We have previously shown that multinucleated cells (MNC) with many features of the osteoclast phenotype form in long term human marrow cultures. Addition of rhIL-6 (10 to 100 pg/ml) to these cultures significantly increased MNC formation, with greater than 80% of the MNC expressing an Ag that cross-reacts with the mAb 23c6. This antibody preferentially binds to osteoclasts. rhIL-6 did not enhance MNC formation in marrow cultures treated with 1,25 dihydroxyvitamin D3, a potent stimulator of MNC formation, but significantly increased the percentage of MNC that cross-reacted with the 23c6 mAb. Addition of antihuman IL-1 to cultures treated with rhIL-6 totally inhibited the increase in MNC formation stimulated by rhIL-6. In contrast, anti-IL-1 did not affect MNC formation stimulated by 1,25 dihydroxyvitamin D3. Further, conditioned media from marrow cultures exposed to rhIL-6 contained elevated levels of IL-1 beta (500 pg/ml compared to 23 pg/ml in control cultures 15 h after IL-6 addition). These results suggest that the capacity of rhIL-6 to stimulate formation of MNC which cross-react with 23c6 is mediated by induction of release of IL-1 beta.

IL-6 stimulates osteoclast-like multinucleated cell formation in long term human marrow cultures by inducing IL-1 release

IL-6 enhances the differentiation of pluripotent hematopoietic stem cells but predominantly affects the differentiation of hematopoietic cells in the granulocyte-macrophage lineage. We have previously shown that multinucleated cells (MNC) with many features of the osteoclast phenotype form in long term human marrow cultures. Addition of rhIL-6 (10 to 100 pg/ml) to these cultures significantly increased MNC formation, with greater than 80% of the MNC expressing an Ag that cross-reacts with the mAb 23c6. This antibody preferentially binds to osteoclasts. rhIL-6 did not enhance MNC formation in marrow cultures treated with 1,25 dihydroxyvitamin D3, a potent stimulator of MNC formation, but significantly increased the percentage of MNC that cross-reacted with the 23c6 mAb. Addition of antihuman IL-1 to cultures treated with rhIL-6 totally inhibited the increase in MNC formation stimulated by rhIL-6. In contrast, anti-IL-1 did not affect MNC formation stimulated by 1,25 dihydroxyvitamin D3. Further, conditioned media from marrow cultures exposed to rhIL-6 contained elevated levels of IL-1 beta (500 pg/ml compared to 23 pg/ml in control cultures 15 h after IL-6 addition). These results suggest that the capacity of rhIL-6 to stimulate formation of MNC which cross-react with 23c6 is mediated by induction of release of IL-1 beta.

Enhancement of the mitochondrial Ca2+ uptake rate by phenethylbiguanide and other organic cations with hypoglycemic activity

At concentrations below 50 micronM, phenethylbiguanide enhanced the initial rate of enertized Ca2+ uptake into energized guinea pig liver mitochondria by as much as 45 per cent; Ca2+-stimulated O2 uptake increased in parallel. The biguanide concentration that enhanced Ca2+ uptake maximally was at least 15 times lower than that required for 50 per cent inhibition of respiration. Kinetic studies indicated that the enhanced rate of Ca2+ transport resulted from an increase in Vmax, while Km for Ca2+ was unaffected by the biguanide. Several other organic cations known to lower blood sugar in intact animals or to block the hepatic gluconeogenic response to glucagon also enhanced the mitochondrial Ca2+ uptake rate; three of these compounds did not inhibit respiration even at high concentrations. One organic cation, triethyltin, which is a potent respiratory inhibitor that does not affect blood sugar, had no effect on Ca2+ uptake. We concluded that enhancement of the mitochondrial Ca2+ uptake rate is related to the mechanism of therapeutic blood sugar lowering by these drugs, probably by impairing the gluconeogenic response of the liver to glucagon.

(+)-alpha-(N-1-phenethyl) urea stereospecifically inhibits Ca2+ - but not ADP-stimulated mitochondrial respiration

The (+) isomer of alpha-(N-1-phenethyl) urea is a moderately potent inhibitor of Ca2+ -stimulated mitochondrial respiration of 45Ca2+ uptake (50 percent inhibition at 0.18 mM) while having no effect on adenosine diphosphate-stimulated respiration; the (-) isomer is without effect up to 4 mM. beta-Phenethylurea does not inhibit with either stimulus. The data support the involvement of a Ca2+ -specific protein in energized mitochondrial Ca2+ uptake.

Physical state in which naphthalene and bibenzyl are utilized by bacteria

The generation times of a strain of Pseudomonas grown on a mineral salts medium in the presence of various amounts of naphthalene did not vary with the amount of solid present, and these generation times were the same as the generation time on mineral salts medium containing only dissolved naphthalene. The generation time of a soil isolate grown on mineral salts medium in the presence of 0.5 g of solid bibenzyl per liter was the same as the generation time on a mineral salts medium saturated with bibenzyl. The evidence indicates that naphthalene and bibenzyl are utilized in the dissolved state.