Skin morphology and its role in thermoregulation in mole-rats, Heterocephalus glaber and Cryptomys hottentotus

The skin structure of 2 Bathyergid rodents, the naked mole-rat ( Heterocephalus glaber ) and the common mole-rat ( Cryptomys hottentotus ) is compared, to investigate whether thermoregulatory differences may be attributed to different skin features. Histological and ultrastructural studies of the dorsal skin of these closely related species show morphological and structural similarities but differences in the degree of skin folding, thickness of the integument and dermal infrastructure were evident. The skin of the common mole-rat conforms with expected morphological/histological arrangements that are commonly found in mammalian skin. Many features of the skin of the naked mole-rat, such as the lack of an insulating layer and the loosely folded morphological arrangement contribute to poikilothermic responses to changing temperatures of this mammal. Further evidence for poikilothermy in the naked mole-rat is indicated by the presence of pigment containing cells in the dermis, rather than the epidermis, as commonly occurs in homeotherms. Lack of fur is compensated by a thicker epidermal layer and a marked reduction in sweat glands. Differences in skin morphology thus contribute substantially to the different thermoregulatory abilities of the 2 Bathyergids. The skin morphology is related to the poor thermoinsulatory ability of the animals while simultaneously facilitating heat transfer from the environment to the animal by thigmothermy and/or other behavioural means.     

The teaching of behavioural sciences

Summary. Medical science over the last few decades has undergone vast changes. Technologically it has advanced at a rapid pace. There has been a realization as well that the behaviour of individuals and communities also influences the occurrence of disease. Medical schools around the globe have realized the need for incorporating behavioural sciences as an integral part of the basic sciences taught to medical students.
This paper presents the experience of Christian Medical College, Veilore in teaching behavioural sciences. Students are taught sociology, psychology and medical anthropology through a community-based, problem-oriented teaching programme. The students have first-hand experience of living in a community and learn by observation and interaction. Pre- and post-assessment has shown a significant improvement of their knowledge and attitude. Feedback from students also indicates that they find this programme relevant and interesting.     

Aneurysm of the Left Main Coronary Artery

Aneurysms of the left main coronary artery are rare; the estimated incidence is < 0.1%. They are usually associated with atherosclerotic coronary artery disease, and are incidental discoveries at the time of cardiac catheterization for the evaluation of cardiac symptoms. This report describes the clinical course of a patient with an isolated left main coronary artery aneurysm and generalized atherosclerosis.     

analysis of CD9, CD32 and p67 signalling: use of degranulated platelets indicates direct involvement of CD9 and p67 in integrin activation

The use of agonist monoclonal antibodies (mAbs) to probe the signalling function of platelet membrane proteins is severely limited by the dependence of the mAb effect on Fc–FcγRII interaction. Furthermore, in addition to its anchoring role, the FcγRII receptor itself generates a stimulation signal resulting in granule secretion. Platelet stimulation by the released granule contents can then further obscure the original activation signal. Here we demonstrate that these problems are largely overcome by the use of platelets which had been degranulated with thrombin prior to stimulation with mAbs. We found that, like intact cells, degranulated platelets could also be activated and induced to aggregate by mAbs against a 67 kD membrane protein (known as PTA1) and CD9, and by crosslinked CD32 (FcγRII). However, the signal generated by crosslinked FcγRII was weak compared with that induced by the other monoclonal antibodies. Thus, by diminishing the FcγRII signal contribution, we have succeeded for the first time to clearly dissect the target antigen signal from that generated by FcγRII. In addition to differences in the degree of aggregation, analysis of the signals generated by each mAb showed differences in Ca²⁺ fluxes and protein phosphorylation. Moreover, the signals generated by CD9 and PTA1 antigens differed significantly in their sensitivity to PKC inhibition or ADP-ribosylation of the small GTP-binding protein rhoA. Despite these differences, the signals initiated by all three antigens converged to a common signalling pathway which included activation of tyrosine kinase(s). The pattern of protein phosphorylation strongly resembled that induced by gpIIb/IIIa-mediated platelet interaction with macromolecular ligands and by mutual cell contact. The multiple intercellular links formed by mAb would have a similar effect since the Fc-receptor anchorage required for antigen stimulation is already known to be provided by adjacent cells. The present findings suggest that the function of both CD9 and PTA1 antigens is closely associated with gpIIb/IIIa activation.     

Leiomyosarcoma of the Right Atrium Masked by a Covering Thrombus: Conflicting Results of Echocardiography and Transvenous Biopsy—In Favor of Echocardiography

A 62-year-old woman was admitted for the evaluation of pedal edema and ascitis. Echocardiography revealed a right atrial (RA) mass invading the interatrial septum and extending into the inferior vena cava (IVC). Contrast enhanced computerized tomography scan excluded extravascular involvement. An organized thrombus was diagnosed by transvenous endomyocardial biopsy. The patient was treated with continuous intravenous heparin, and died soon after from hepatic failure. Postmortem histologic examination revealed a leiomyosarcoma surrounded by a thrombus involving RA, IVC, and hepatic veins. Endomyocardial biopsy played a misleading role that affected patient's management.     

Endoscopic Retrograde Cholangiopancreatography in Laparoscopic Cholecystectomy

Abstract: With the widespread use of laparoscopic cholecystectomy (LC), the role of pre- and postoperative endoscopic retrograde cholangiopancreatography (ERCP) and / or endoscopic sphincterotomy (ES) has become very important. Indications for ERCP with possible ES before LC include clinical suspicion of a common bile duct (CBD) stone alone, evidence of jaundice, recent cholangitis or pancreatitis that is probably due to a duct stone or dilated CBD. Local endoscopic and surgical expertise are important factors in deciding the approach to the pre-LC patients. The success rate of ductal clearance of stones by ES approaches 90 to 95% in expert hands. ERCP is very effective in the management of post-LC patients with symptoms, as well as in diagnosing and treating complications such as retained stones, ductal leaks and strictures.     

Cremation of Leadless Pacemaker

Cremation of implanted cardiac electronic devices can be associated with explosion from rapid gas formation causing potential hazard to the crematoria staffs and facilities. We present four patients who had undergone cremation with a leadless pacemaker (Micra^TM, Medtronic Inc., Minneapolis, MN, USA) left inside their bodies. There was neither reported explosion nor damage to the cremation chamber during the cremation process. In this small series, cremation of Micra^TM is not associated with noticeable explosion.