Histological evaluation of cardiac remodelling in equine athletes.

Approximately 1-2 per 100,000 young athletes die from sudden cardiac death (SCD) and extreme exercise may be associated with myocardial scar and arrhythmias. Racehorses have a high prevalence of atrial fibrillation (AF) and SCD but the presence of myocardial scar and inflammation has not been evaluated. Cardiac tissues from the left (LAA) and right (RAA) atrial appendages, left ventricular anterior (LVAPM) and posterior (LVPPM) papillary muscles, and right side of the interventricular septum (IVS-R) were harvested from racehorses with sudden cardiac death (SCD, n = 16) or other fatal injuries (OFI, n = 17), constituting the athletic group (ATH, n = 33), and compared to sedentary horses (SED, n = 10). Horses in the ATH group had myocyte hypertrophy at all sites; increased fibrosis at all sites other than the LAA; increased fibroblast infiltration but a reduction in the overall extracellular matrix (ECM) volume in the RAA, LVAPM, and IVS-R compared to SED horses. In this horse model, athletic conditioning was associated with myocyte hypertrophy and a reduction in ECM. There was an excess of fibrocyte infiltration and focal fibrosis that was not present in non-athletic horses, raising the possibility of an exercise-induced pro-fibrotic substrate.

Anatomy and evolution of the first Coleoidea in the Carboniferous.

Coleoidea (squids and octopuses) comprise all crown group cephalopods except the Nautilida. Coleoids are characterized by internal shell (endocochleate), ink sac and arm hooks, while nautilids lack an ink sac, arm hooks, suckers, and have an external conch (ectocochleate). Differentiating between straight conical conchs (orthocones) of Palaeozoic Coleoidea and other ectocochleates is only possible when rostrum (shell covering the chambered phragmocone) and body chamber are preserved. Here, we provide information on how this internalization might have evolved. We re-examined one of the oldest coleoids, Gordoniconus beargulchensis from the Early Carboniferous of the Bear Gulch Fossil-Lagerstätte (Montana) by synchrotron, various lights and Reflectance Transformation Imaging (RTI). This revealed previously unappreciated anatomical details, on which we base evolutionary scenarios of how the internalization and other evolutionary steps in early coleoid evolution proceeded. We suggest that conch internalization happened rather suddenly including early growth stages while the ink sac evolved slightly later.

Syn-vivo bioerosion of Nautilus by endo- and epilithic foraminiferans (New Caledonia and Vanuatu).

A variety of syn-vivo bioerosion traces produced by foraminiferans is recorded in shells of Nautilus sampled near New Caledonia and Vanuatu. These are two types of attachment scars of epilithic foraminiferans and two forms of previously undescribed microborings, a spiral-shaped and a dendritic one, both most likely being the work of endolithic 'naked' foraminiferans. Scanning electron microscopy of epoxy-resin casts of the latter revealed that these traces occur in clusters of up to many dozen individuals and potentially are substrate-specific. The foraminiferan traces are the sole signs of bioerosion in the studied Nautilus conchs, and neither traces of phototrophic nor other chemotrophic microendoliths were found. While the complete absence of photoautotrophic endoliths would be in good accordance with the life habit of Nautilus, which resides in aphotic deep marine environments and seeks shallower waters in the photic zone for feeding only during night-time, the absence of any microbial bioerosion may also be explained by an effective defence provided by the nautilid periostracum. Following this line of reasoning, the recorded foraminiferan bioerosion traces in turn would identify their trace makers as being specialized in their ability to penetrate the periostracum barrier and to bioerode the shell of modern Nautilus.

An unusual occurrence of Nautilus macromphalus in a cenote in the Loyalty Islands (New Caledonia).

Exploration of a landlocked cenote on Lifou (Loyalty Islands) revealed 37 shells of the cephalopod Nautilus macromphalus Sowerby, 1849, in saltwater on the cenote floor, approximately 40 m below the water surface. The occurrence of these shells is unusual because N. macromphalus is restricted to the open marine waters surrounding the island. All of the shells are mature, and nearly all of them are unbroken, with faded red-brown color stripes. We analyzed seven shells to determine their age. Radiocarbon dating yielded ages of 6380±30 to 7095±30 y BP. The 238U-series radionuclides 210Pb (half-life  = 22.3 y) and 226Ra (half-life  = 1600 y) also were measured. Two of the samples showed radioactive equilibrium between the nuclides, consistent with the old radiocarbon dates, but the other five samples showed excess 210Pb. When corrected for radioactive decay, the 226Ra activities were much greater than those found in living Nautilus. We conclude that exposure to high activities of 222Rn and 226Ra in the salty groundwater of the cenote altered the activities originally incorporated into the shells. Human placement of the shells in the cavity is rejected based on their radiocarbon age and the geometry of the cenote. The most probable explanation is that the animals entered the flooded karstic system through a connection on the seaward side at approximately 7,000 y BP, during an interval of slowly rising sea level. Unable to find an exit and/or due to anoxic bottom waters, the animals were trapped and died inside. The open connection with the sea persisted for ∼700 y, but after ∼6400 y BP, the connection was lost, probably due to a roof collapse. This is a rare example of Nautilus in a karstic coastal basin and provides a minimum age for the appearance of N. macromphalus in the Loyalty Islands.

A Palaeozoic shark with osteichthyan-like branchial arches.

The evolution of serially arranged, jointed endoskeletal supports internal to the gills--the visceral branchial arches--represents one of the key events in early jawed vertebrate (gnathostome) history, because it provided the morphological basis for the subsequent evolution of jaws. However, until now little was known about visceral arches in early gnathostomes, and theories about gill arch evolution were driven by information gleaned mostly from both modern cartilaginous (chondrichthyan) and bony (osteichthyan) fishes. New fossil discoveries can profoundly affect our understanding of evolutionary history, by revealing hitherto unseen combinations of primitive and derived characters. Here we describe a 325 million year (Myr)-old Palaeozoic shark-like fossil that represents, to our knowledge, the earliest identified chondrichthyan in which the complete gill skeleton is three-dimensionally preserved in its natural position. Its visceral arch arrangement is remarkably osteichthyan-like, suggesting that this may represent the common ancestral condition for crown gnathostomes. Our findings thus reinterpret the polarity of some arch features of the crown jawed vertebrates and invert the classic hypothesis, in which modern sharks retain the ancestral condition. This study underscores the importance of early chondrichthyans in resolving the evolutionary history of jawed vertebrates.

A large multicenter outcome study of female genital plastic surgery.

INTRODUCTION: Female Genital Plastic Surgery, a relatively new entry in the field of Cosmetic and Plastic Surgery, has promised sexual enhancement and functional and cosmetic improvement for women. Are the vulvovaginal aesthetic procedures of Labiaplasty, Vaginoplasty/Perineoplasty ("Vaginal Rejuvenation") and Clitoral Hood Reduction effective, and do they deliver on that promise? For what reason do women seek these procedures? What complications are evident, and what effects are noted regarding sexual function for women and their partners? Who should be performing these procedures, what training should they have, and what are the ethical considerations? AIM: This study was designed to produce objective, utilizable outcome data regarding FGPS. MAIN OUTCOME MEASURES: 1) Reasons for considering surgery from both patient's and physician's perspective; 2) Pre-operative sexual functioning per procedure; 3) Overall patient satisfaction per procedure; 4) Effect of procedure on patient's sexual enjoyment, per procedure; 5) Patient's perception of effect on her partner's sexual enjoyment, per procedure; 6) Complications. METHODS: This cross-sectional study, including 258 women and encompassing 341 separate procedures, comes from a group of twelve gynecologists, gynecologic urologists and plastic surgeons from ten centers in eight states nationwide. 104 labiaplasties, 24 clitoral hood reductions, 49 combined labiaplasty/clitoral hood reductions, 47 vaginoplasties and/or perineoplasties, and 34 combined labiaplasty and/or reduction of the clitoral hood plus vaginoplasty/perineoplasty procedures were studied retrospectively, analyzing both patient's and physician's perception of surgical rationale, pre-operative sexual function and several outcome criteria. RESULTS: Combining the three groups, 91.6% of patients were satisfied with the results of their surgery after a 6-42 month follow-up. Significant subjective enhancement in sexual functioning for both women and their sexual partners was noted (p = 0.0078), especially in patients undergoing vaginal tightening/perineal support procedures. Complications were acceptable and not of major consequence. CONCLUSIONS: While emphasizing that these female genital plastic procedures are not performed to correct "abnormalities," as there is a wide range of normality in the external and internal female genitalia, both parous and nulliparous, many women chose to modify their vulvas and vaginas. From the results of this large study pooling data from a diverse group of experienced genital plastic surgeons, outcome in both general and sexual satisfaction appear excellent.

Whole body, adipose tissue, and forearm norepinephrine kinetics in lean and obese women.

We evaluated whole body and regional (subcutaneous abdominal adipose tissue and forearm) norepinephrine (NE) kinetics in seven lean (body mass index 21.3 +/- 0.5 kg/m2) and six upper body obese (body mass index 36.4 +/- 0.4 kg/m2) women who were matched on fat-free mass. NE kinetics were determined by infusing [3H]NE and obtaining blood samples from a radial artery, a deep forearm vein draining mostly skeletal muscle, and an abdominal vein draining subcutaneous abdominal fat. Mean systemic NE spillover tended to be higher in obese (2.82 +/- 0.49 nmol/min) than in lean (2.53 +/- 0.40 nmol/min) subjects, but the differences were not statistically significant. Adipose tissue and forearm NE spillover rates into plasma were greater in lean (0.91 +/- 0.08 pmol. 100 g tissue-1. min-1 and 1.01 +/- 0.09 pmol. 100 ml tissue-1. min-1, respectively) than in obese (0.26 +/- 0.05 pmol. 100 g tissue-1. min-1 and 0.58 +/- 0.11 pmol. 100 ml tissue-1. min-1, respectively) subjects (P < 0.01). These results demonstrate that adipose tissue is an active site for NE metabolism in humans. Adipose tissue NE spillover is considerably lower in obese than in lean women, which may contribute to the lower rate of lipolysis per kilogram of fat mass observed in obesity.

Recurrent gastrointestinal bleeding: use of thrombolysis with anticoagulation in diagnosis.

PURPOSE: To determine the safety and diagnostic accuracy of a provocative protocol with heparin and urokinase to induce bleeding and determine the source in patients with chronic gastrointestinal hemorrhage. MATERIALS AND METHODS: Nine patients had gastrointestinal bleeding from an indeterminate source and had negative results from esophagogastroduodenoscopy, colonoscopy, small-bowel examination, and angiography. Ten provocative bleeding studies were performed prospectively. Patients had no clinical evidence of bleeding within 2 days before the study. Intravenous administration of heparin and urokinase was performed systemically during a 4-hour period while scintigraphy was performed continuously. Mesenteric angiography was performed immediately in patients in whom substantial gastrointestinal bleeding was detected at scintigraphy. RESULTS: The provocative protocol was successful in inducing scintigraphically detectable hemorrhage in four (40%) studies within 4 hours. In two of these four studies, the source of hemorrhage was determined and treated with embolization or surgery. Three (30%) studies demonstrated scintigraphic evidence of hemorrhage only at delayed imaging (8-24 hours after initiation of the study). The remaining three (30%) studies did not show active bleeding. No complications occurred, including hemodynamic instability or uncontrollable decreases in hematocrit. CONCLUSION: Since this protocol with heparin and urokinase enabled determination of the bleeding source in only two of 10 studies, protocol modifications are necessary before this intervention is used widely.