THE RELATIONSHIP among cardiac pacemakers is characterized by the fact that usually one pacemaker is dominant and all the others are subsidiary. The sinoatrial node acts as the dominant pacemaker and all other pacemaker tissues are discharged by a conducted impulse before their diastolic depolarization can attain threshold. These pacemakers are called subsidiary to emphasize the fact that under...

THE RELATIONSHIP among cardiac pacemakers is characterized by the fact that usually one pacemaker is dominant and all the others are subsidiary. The sinoatrial node acts as the dominant pacemaker and all other pacemaker tissues are discharged by a conducted impulse before their diastolic depolarization can attain threshold. These pacemakers are called subsidiary to emphasize the fact that under...

The spontaneous activity of pacemaker cells in the sino-atrial node (SAN) controls the heart rhythm and rate under physiological conditions. Pacemaker activity in SAN cells is due to the presence of the diastolic depolarization, a slow depolarization phase that drives the membrane voltage from the end of an action potential to the threshold of a new action potential. SAN cells express a wide ar...

Palisaded granulomatous dermatitis is an uncommon pathologic condition potentially associated with several disorders. These include drugs, inflammatory bowel disease, multiple myelomas, rheumatoid arthritis, and systemic lupus erythematosus. An illustrative case of a man with palisaded granulomatous dermatitis who subsequently developed ulcerative colitis is described, and the characteristics o...

Health technology The study compared two treatment strategies for patients with chronic heart failure (CHF). The strategies compared were the conventional strategy and the pacemaker-carvedilol strategy. In the conventional strategy, patients were treated with angiotensin-converting enzyme inhibitors, diuretics and digoxin. In the pacemaker-carvedilol strategy, patients received conventional tre...

The use of cardiac pacemakers is increasing worldwide. Infective endocarditis from a pacemaker lead is a rare, but one of the most severe complications of pacemaker insertion. The diagnosis of pacemaker-related infective endocarditis is usually delayed due to unspecific clinical signs and symptoms at presentation compared to native valve infective endocarditis. Several factors can increase the ...

Parthenium dermatitis is an immuno-inflammatory disease caused by Parthenium hysterophorus and is the commonest cause of plant dermatitis in India. It is caused by airborne dry and friable plant particles including trichomes, and the most important allergens responsible for allergic contact dermatitis are sesquiterpene lactones. The combined type IV and type I hypersensitivity to parthenium has...

Each eye of Aplysia contains a population of electrically coupled pacemaker neurons whose synchronous activity can be recorded from the optic nerve as a compound action potential (CAP). The CAP frequency continues to show a circadian rhythm even when the eye is isolated from the animal and maintained in constant conditions, and thus it contains an autonomous circadian pacemaker, which may resid...

BACKGROUND A chronic dermatosis like nummular dermatitis may be complicated by contact dermatitis due to an impaired cutaneous barrier. This study is aimed at evaluating secondary contact dermatitis in patients with nummular dermatitis. METHODS Patch testing with the Indian Standard Series was performed in 50 of 78 patients with a clinical diagnosis of nummular eczema. Significant reactions w...

1. Textiles and shoes. In: Fisher’s contact dermatitis. 6th ed. Hamilton, Ontario: Bc Decker Inc.; 2008. p. 339--69. 2. Warshaw EM, Schram SE, Belsito DV, DeLeo VA, Fowler Jr JF, Maibach HI, et al. Shoe allergens: retrospective analysis of cross-sectional data from the North American contact dermatitis group, 2001--2004. Dermatitis. 2007;18:191. 3. Fleming AJ. The provocative test for assaying ...