Regeneration of Functional Adrenal Tissue Following Bilateral Adrenalectomy.

It is assumed that after complete bilateral adrenalectomy (ADX), no adrenal tissue will redevelop and adrenal hormone levels will remain low and unaffected by stress. However, anecdotal observations in animals and in patients suggest that under some unknown circumstances the opposite can occur. Herein, we studied whether adrenalectomized rats can develop an alternative source of systemic corticosterone after complete bilateral ADX with minimal replacement therapy. Male and female rats underwent either a standard ADX, in which the glands were removed with minimal surrounding adipose tissue, or an extensive ADX, in which glands were removed with most surrounding adipose tissue. Excised glands were histologically tested for completeness, and corticosterone replacement was nullified within 1 to 3 weeks postoperatively. In four experiments and in both excision approaches, some rats gradually reestablished baseline corticosterone levels and stress response in a time-dependent manner, but differences were observed in the reestablishing rates: 80% in standard ADX vs 20% in extensive ADX. Upon searching for the source of corticosterone secretion, we were surprised to find functional macroscopic foci of adrenocortical tissue without medullary tissue, mostly proximal to the original location. Chronic stress accelerated corticosterone level reestablishment. We hypothesized that underlying this phenomenon were preexisting ectopic microscopic foci of adrenocortical-like tissue or a few adrenal cells that were pre-embedded in surrounding tissue or detached from the excised gland upon removal. We concluded that adrenalectomized animals may develop compensatory mechanisms and suggest that studies employing ADX consider additional corticosterone supplementation, minimize stress, and verify the absence of circulating corticosterone.

Ectopic pancreatic pseudocyst and cyst presenting as a cervical and mediastinal mass: case report and review of the literature.

Ectopic pancreas in the mediastinum is extremely rare. We are reporting on a case of a twenty two year old woman who presented to our clinic with a large cervical mass. The CT scan revealed a cystic lesion in the anterior mediastinum. The patient underwent surgical resection by cervical approach. A Cystic mass with pseudocysts, cysts and complete pancreatic tissue were found in pathology. There were no signs of pancreatitis or malignancy. No recurrence was observed after a follow up of four years. We reviewed the case reports describing this rare condition in the medical literature.We conclude that the possibility of ectopic pancreatic tissue should be included in the differential diagnosis of anterior mediastinal cystic mass, though as a remote possibility. Surgery is probably needed for the diagnosis and treatment. Posterior mediastinal pseudocyst is a different entity associated with acute pancreatitis. In those cases surgery is not recommended. Our third conclusion is that pancreatic tissue should be actively sought, if a structure resembling a pseudocyst is found in an unexpected location. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1849369005957671.

Early blood pressure-independent cardiac changes in diabetic rats.

Cardiac remodeling is a key event in both diabetic and hypertensive heart diseases. In the present study, we investigated early myocardial changes in an animal model, the male Sabra rat model (SBH/y) of salt-induced hypertension-rendered diabetic with streptozotocin. Control non-diabetic (C), diabetic (D), and D or C rats made hypertensive by salt loading (DS or CS) were studied after 6 weeks. M-mode echocardiography revealed that left ventricular internal dimension during diastole and systole were significantly increased in D and DS, but not in C or CS. Concurrently, we found in D and DS an increase in cardiac beta-myosin heavy chain, atrial natriuretic peptide, skeletal alpha-actin mRNA, type III collagen, and transforming growth factor-beta. Myocardial angiotensin-converting enzyme (ACE) mRNA levels were increased while ACE2 mRNA levels were decreased in both D and DS groups. Cardiac angiotensin-1 (AT1) receptor protein levels were unchanged but the levels of phosphorylated (p) ERK and Jun-NH(2)-protein kinase (JNK) were increased in D and DS. In conclusion, we detected early cardiac changes in diabetic rats that were unrelated to hypertension. The increase in ACE, the decrease in ACE2, and the increase in cardiac pERK and pJNK suggest an increase in free angiotensin II and AT1R signaling in the diabetic myocardium as a possible mechanism contributing to cardiac remodeling in diabetes.