Morphological characteristics of the sinus node on postmortem tissue.

The sinus node is an intensively researched structure in terms of anatomical, histological, electrophysiological, molecular and genetic approach. For postmortem diagnosis it is still difficult to investigate due to a still reduced accessibility. In this study we tried and succeed to apply molecular biology techniques on postmortem tissues in order to widen the range of postmortem forensic investigation and provide information related to the diagnostic of cardiac arrhythmia. We described the stages of this investigation, with dissection, preservation and analysis that included classical histology, immunohistochemistry, confocal microscope, microdissection, RIN testing, mRNA expression obtaining a precise morphofunctional location of the sinus node.

Sudden cardiac death due to triple myocardial bridging associated with atypical coronary topography.

Myocardial bridging (MB) is defined as the presence of an intramural course of a coronary artery, most likely caused by a defect in resorption of the musculature that encircles the epicardial arteries during morphogenesis. We present a case of the young man who died suddenly while playing professional football and whose cause of death was acute myocardial infarction associated with multiple myocardial bridges (1.8 cm on the anterior interventricular artery, 1.3 cm on the circumflex artery, and an intramyocardial trajectory of the posterior interventricular artery), and discuss the causes of death and possible consequences of this pathology.

The human trigeminal ganglion: c-kit positive neurons and interstitial cells.

OBJECTIVES: The presence of c-kit positive neurons in sensory ganglia has been verified in various species but not in humans. Our aim has been to identify whether human primary trigeminal neurons label with c-kit/CD117 and thus, whether data gathered in animal studies can be extrapolated to humans. We also intended to establish whether, and which non-neuronal cells also label with c-kit in the trigeminal ganglion. METHODS: Human adult trigeminal ganglia from eight cadavers were processed for immunohistochemistry on paraffin embedded samples using monoclonal antibodies for CD117/c-kit, and three additional trigeminal ganglia were used for transmission electron microscopy (TEM). To evaluate which neuronal type (A or B) was labeled with c-kit, we evaluated the same neurons on adjacent sections labeled with antibodies for neurofilaments (NF). RESULTS: c-kit has labeled trigeminal neurons (TNs), mast cells and interstitial cells (ICs) within the trigeminal ganglion. c-kit+TNs were NF-and thus were strongly presumed to be nociceptive, as such neurons are known to be NF-poor. c-kit+ICs with long and moniliform processes intermingled with the satellite glial cells (SGCs) of the neuronal envelopes. TEM evaluations confirmed this mixed composition of the neuronal envelopes and demonstrated that the perineuronal ICs are in fact interstitial Cajal-like cells (ICLCs) and/or telocytes. CONCLUSIONS: c-kit+TNs were objectified in humans and strongly presumed to be nociceptive. TNs envelopes mostly consist of SGCs, but are also combined with ICLCs/telocytes.

Can subclinical hypothyroidism explain some sudden deaths due to pulmonary embolism without evident risk factors?

Thyroid pathology is rarely involved in the pathogenesis of sudden death in young people, and usually, when this is the case, is associated with acute changes of thyroid hormone blood levels. Three main thyroid causes of sudden death are known and used in tanathologic chains: thyrotoxicosis, myxedematous coma and, as of recently, lymphocytic thyroid infiltration. Coagulation disorders associated with thyroid disease are usually mild and not associated with sudden death. There are some studies showing an increased risk for unprovoked deep venous thrombosis in patients with hypothyroidism but there is none, to our knowledge, showing a correlation between hypothyroidism, deep venous thrombosis and sudden death. Our article suggests that subclinical hypothyroidism can lead to coagulation disorders and deep venous thrombosis which can explain some cases of sudden death associated with pulmonary embolism without other significant risk factors.

Morphological changes associated with hemodynamically significant myocardial bridges in sudden cardiac death.

UNLABELLED: Although myocardial bridging (MB) is a common coronary anomaly, its cardiovascular consequences are still disputed. A positive link between sudden cardiac death (SCD) and myocardial bridging has not yet been definitively proved, even though many case reports and small scale studies support this association. For myocardial bridging to be associated with sudden cardiac death it must exhibit certain specific characteristics involving coronary or myocardial changes sufficient to explain a terminal cardiac event. In this study we aimed to analyze the morphological changes (both myocardial and coronary) associated with hemodynamically significant myocardial bridging and the morphological differences between hemodynamically significant MB and MB considered to be non-hemodynamically significant. MATERIAL AND METHOD: We analyzed 53 cases of sudden cardiac death, of which 21 cases had hemodynamically significant myocardial bridging, 14 had non-hemodynamically significant myocardial bridging and 20 cases suffered sudden cardiac death without myocardial bridging, using a morphological score with seven histological parameters. RESULTS: Myocardial fibrosis and interstitial edema were found to be highly correlated with hemodynamically significant myocardial bridging (HSMB), as were interstitial edema and interstitial fibrosis. CONCLUSIONS: Hemodynamically significant myocardial bridging can be discovered during heart dissection by analyzing a series of morphological markers (width, distribution of atherosclerosis, distal hypoplasia). Our study showed that MB was associated with increased myocardial fibrosis and edema, both of which have an increased risk of electrical instability. Compared to non-hemodynamically significant myocardial bridging, HSMB shows a distinct histological pattern, with increased myocardial fibrosis and edema. The main cause of SCD in association with HSMB seems to be electrical due to increased electrical myocardial heterogeneity, but large scale studies are needed to test this.

Anatomical and immunohistochemical considerations on the microinnervation of trachea in humans.

The anatomy of the tracheal microinnervation is understudied in humans; the purpose of our study was to fill this gap by working on human adult tracheas, to compare the results with those obtained from animal studies, and to checking whether or not these studies are suitable to be translated from comparative to the human anatomy. The study was designed as a qualitative one. The present work was performed on human adult tracheas dissected out in 15 human adult cadavers. Microdissections were performed in eight tracheas and revealed the outer peritracheal plexus, segmentally supplied and distributed to trachea and esophagus, with longitudinal intersegmentary anastomoses but also with bilateral interrecurrential anastomoses previously undescribed in anatomy. Seven different tracheas were transversally cut and paraffin embedded. Histological stains (HE, toluidine blue, luxol fast blue, Giemsa on tissues and trichrome Gieson) and immunohistochemistry using primary antibodies for nNOS, neurofilament, SMA and the cocktail of citokeratines CK AE1-AE3+8/18 were done. According to the histological individual variation, the neural layers of the posterior wall of the human trachea could be considered as it follows: (a) an outer neural layer, ganglionated, associated with the connective covering layers, adventitia and the posterior fibroelastic membrane (external elastic lamina); (b) a submucosal ganglionated neural layer, mainly with juxtaglandular microganglia that may expand, as glands do, through the outer covering layers; (c) intrinsic nerves of the transverse trachealis muscle; (d) the neural layer intrinsic to the longitudinal elastic band (internal elastic lamina) and supplied from the inner submucosa; (e) the neural plexus of the lamina propria, with scarcely distributed neurons. We also bring here the first evidences for the in vivo nNOS phenotype of mast cells that were identified, but not exclusively, within the trachealis muscle.

The iliolumbar artery-anatomic considerations and details on the common iliac artery trifurcation.

The iliolumbar artery (ILA) of Haller is the largest nutrient pedicle of the ilium and its detailed knowledge is important for various surgical procedures that approach the lumbosacral junction, the L4/L5 disk space, the sacroiliac joint, the iliac and psoas muscles, or the lumbar spine. Also the ILA is relevant for various techniques of embolization. We aimed to evaluate the anatomic and topographic features of the ILA, by dissection on 30 human adult pelvic halves and on 50 angiograms. ILA was a constant presence and it emerged at Level A (from the common iliac artery (CIA), 8.75%), Level B (from the CIA bifurcation, 2.5%), Level C (from the internal iliac artery (IIA), 52.5%), Level D (from the IIA bifurcation, 3.75%), and Level E (from the posterior trunk of the IIA, 32.5%). Level B of origin of the ILA corresponds to a trifurcated CIA (morphology previously unreported), while Level D corresponds to a trifurcated IIA. A higher origin of the ILA corresponds to a more transversal course of it. A descending lumbar branch that leaves the iliac arterial system independently to enter the psoas major muscle, as seen in 48% of cases, may be misdiagnosed as ILA. Surgical interventions in the lumbar, sacral, and pelvic regions must take into account the variable origins of the ILA from the iliac system that can modify the expected topographical relations and may lead to undesired hemorrhagic accidents.

Simultaneous immunophenotypical assessment of troponin and extracellular matrix molecules in myocardium of patients with sudden cardiac death.

In patients with sudden unexpected cardiac death, there is a relationship between the interstitial fibrosis of the myocardium and matrix molecules with a role in global remodeling of the cardiac stroma. Tissue samples of left ventricular myocardium from 17 middle-aged patients with sudden cardiac death, following acute or chronic ischemic cardio(myo)pathies, were analyzed using standard HE stain and the indirect tristadial ABC peroxidase immunohistochemical method for a panel of four antibodies involved in the dynamic remodeling of extracellular matrix: matrix metalloproteinase 9 (MMP9), tenascin X (Tn-X), TGF-b, CD54 (ICAM-1), together with simultaneously assessment of troponin in myocardic fibers. The most sensitive reaction was noticed for ICAM-1 in 71% of cases, followed by MMP9 in 59% of cases and TGF-b in 47% of cases (with great specificity for capillary vessels), in the extracellular matrix of the residual cardiomyocytes. A direct correlation, statistically significant was recorded between troponin and MMP9 (r = 0.65, p = 0.01), troponin and ICAM-1 (r = 0.31, p = 0.02), respectively ICAM-1 and tenascin (r = 0.72, p = 0.01). The extensive expression of ICAM-1 in the extracellular matrix from the perilesional area probably plays a role in the stimulation of new developing adhesion substrates between residual cells and adjacent stroma, while the over expression of troponin in the residual cardiomyocytes is accompanied by a high expression of MMP9 in the myocardic interstitium, with heterogeneous remodeling of the ventricular stroma. The simultaneous IHC expression of tenascin and ICAM-1 suggests a colocalization required for the nerve sprouting in the residual myocardium and for developing new focal cell-matrix adhesion contacts.

Georges Marinesco and the early research in neuropathology.

OBJECTIVE: To present the scientific contributions of Georges Marinesco (1863-1938) and place his achievements within the context of early neuropathology research. BACKGROUND: Neuropathology is a relatively recent medical field, its origins dating to the late 19th century. RESULTS: One of the most important neuroscientists of that period was the Romanian-born Georges Marinesco. He became a neurologist under Charcot's guidance at the Salpêtrière Hospital, in Paris. In 1892, Paul Blocq and Marinesco gave a first account of senile plaques, having used their pathologic skills in the examination of nine deceased epileptic patients. They did not, however, relate the plaques to dementia. Marinesco made discoveries in neuropathology which he described from a histopathologic perspective, and introduced new medical terms such as neuronophagia, chromatolysis, and medullomyoblastoma. He also drew correlations between clinical neurologic findings and morphology, for example in congenital cerebellar ataxia, syringomyelia, and parkinsonism. From 1899 he used cinematography as a medical research tool. CONCLUSION: Marinesco was a prolific researcher in the field of neuropathology, especially neurodegeneration but also in clinical neurology. He is now considered the founder of the modern Romanian school of neurology.

The electrocardiographic abnormalities in highly trained athletes compared to the genetic study related to causes of unexpected sudden cardiac death.

BACKGROUND: Electrocardiograms in elite endurance athletes sometimes show bizarre patterns suggestive of inherited channelopathies (Brugada syndrome, long QTc, catecholaminergic polymorphic ventricular tachycardia) and cardiomyopathies (arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy) responsible for unexpected sudden cardiac death. Among other methods, genetic analyses are required for correct diagnosis. OBJECTIVE: To correlate 12-lead electrocardiographic patterns suggestive of inherited channelopathies and cardiomyopathies to specific genetic analyses. DESIGN: Prospective study (2004-2007) of screening 12-lead ECG tracings in standard position and higher intercostal spaces V1 to V3 precordial leads, performed in athletes and normal sedentary subjects aged match. Genetic analyses of subjects with ECG abnormalities suggested inherited channelopathies and cardiomyopathies. SETTING: All cardiologic exams and electrocardiograms were performed at "Prof. Dr. C.C. Iliescu" National Institute of Cardiovascular Diseases (Bucharest, Romania). The genetic studies were done at "Mina Minovici" National Institute of Forensic Medicine (Bucharest, Romania). PARTICIPANTS: 347 elite endurance athletes (seniors--190, juniors--157), mean age of 20; 200 subjects mean age of 21, belonging to the control group of 505 normal sedentary population. RESULTS: Seniors. RSR' (V1 to V3) pattern, in 45 cases (23.68%), 5 of them with questionable Brugada sign (elevated J wave and "coved" ST segment, < 2 mm in one lead, V1. Typically, Brugada 1 sign was found in one case (0.52%) with no SCN5A abnormalities. One athlete (0.52%) had normal ECG and exon1 SCN5A duplication. MRI confirmed three arrhythmic right ventricular cardiomypathy epsilon waves (1.57%), in one case. ST-segment elevation myocardial injury like in V1-V3 precordial leads in 34 athletes (17.89%). Genetic analyses-no gene mutations. Juniors. Upright J wave was found in 43 cases (27.38%). Convex ST segment elevation in V1-V3/V4, in 39 cases (24.84%). Bifid T wave with two distinct peaks was found in 39 cases (24.84%), 5 of them with mild prolonged QTc (0.48"-0.56") and KCN genes mutations. Nine (5.73%) of the elevated ST segment juniors had questionable Brugada sign, two of which with KCN (n=1) and SCN5A (n=1) gene mutations. Ajmaline provocative test was negative in 4 and was refused by 5 subjects. CONCLUSION: Bizarre QRS, ST-T patterns suggestive of abnormal impulse conduction in the right ventricle, including the right outflow tract, associated with prolonged QTc interval in some cases were observed in highly trained endurance athletes. The genetic analyses, negative in most athletes, identified surprising mutations in SCN5A and KCN genes in some cases.

Immunophenotypical pleomorphism expression in sudden cardiac death.

This study was undertaken to assess several histopathological and immunohistochemical markers regarding some lesional aspects of ischemically and hypoxically damaged myocardium in sudden cardiac death. Tissue samples of myocardium from 17 middle age and young patients with sudden cardiac death, following acute or chronic cardio(myo)pathies, were analyzed using standard HE stain and indirect tristadial ABC peroxidase immunohistochemical method, for a panel of 12 antibodies grouped in three categories: antibodies involved in programmed cell death (bcl-2, p53, Fas/CD95, Fas-L, bax, caspase 9), muscular markers (Myo-D1, myogenin, desmin, actin) and growth factor receptors (b-FGF, VEGF, NGF). Myogenin was more sensitive in identifying the ischemic perilesional myocardic fibers than Myo-D1, but less specific, while desmin had a greater sensitivity than myogenin and Myo-D1 taken separately, but with no specificity for myocardic fibers. Fas-L, caspase 9 and bax were expressed in more than 75% of cases in perilesional residual cardiomyocytes, correlating to each other (r = 0.45, respectively r = 0.6, p<0.05). b-FGF, VEGF and NGF had a focally variable expression in subendocardial and subepicardial cardiomyocytes and were statistically independent. Even if there was a polymorphic expression of antibodies in the studied batch, our findings indicate that some parameters (Fas-L, b-FGF, Myo-D1) might be independent markers for predicting sudden cardiac death in patients with previously damaged myocardium.