Preoperative Localization of Parathyroid Adenomas Using 4-Dimensional Computed Tomography: A Pictorial Essay

Accurate preoperative localization is the key to successful parathyroid surgery in the era of minimally invasive parathyroid surgery. This article presents and discusses the embryologic basis of parathyroid gland and ectopic location and different imaging modalities helpful in diagnosing and localizing parathyroid adenomas and/or hyperplasia. We also aim to review the current surgical concepts in treatment of parathyroid adenomas and/or hyperplasia, the utility of 4-dimensional computed tomography for accurate preoperative localization of hyperfunctioning parathyroid glands, imaging classification of adenomas and/or hyperplasia, and, finally, present some of the limitations of 4-dimensional computed tomography.     

Thoracoscopic approach of the internal mammary artery (IMA): a training model in pigs

Endoscopic internal mammary artery (IMA) approach represents a well-established procedure in coronary bypass surgery. However, such techniques require highly trained skills that need to be mastered in experimental models before taken into the clinic. To attain such skills, our aim was to develop a training model of thoracoscopic approach for harvesting of the IMA in pig. Ten pigs of either sex, weighing 20-28 kg, were used. The thoracic cavity was accessed with the animal in a lateral decubit position, through two ports of 10 mm and 1 of 5 mm, inserted on the anterior and posterior axillary lines immediately below the infrascapular angle into the pleural cavity, and a 30 degrees Hopkins II telescope. The internal mammary artery (IMA) was identified and dissected from its origin in the subclavian artery until its distal part where it becomes the deep superior epigastric artery. Afterward, the arterial segment was clipped and harvested. The mean operative time was 73 min. Postoperative survival at 72 hours was 100% and 90% at 4 weeks. A mean length of 3.2 cm of IMA graft was obtained (2.8-4 cm). The pig IMA has no intercostal branches; thus, the mobilization of the vessel being greatly facilitated. The procedure has two critical steps: the proper trocar insertion and the dissection of the middle one-third of the IMA. Endoscopic-assisted IMA, harvesting in pigs, represents a useful tool for training in minimally invasive heart surgery and supports further development toward other clinical applications.     

The clinical anatomy of the mitral valve

As a result of the numerous clinical and surgical data accumulated so far, the classical image of the mitral valve-a bicuspid valve, with two leaflets and two papillary muscles-undergoes significant modifications. The valve, included into the larger concept of the mitral valvular complex unveils numerous important valences and characteristics, among which, some represent newer concepts, of clinical and surgical significance: the valvular complex is a subtle and finely-tuned system of elements acting in a coordinated manner; the mitral valve is an active valve and not a mere passive flap bordering the atrioventricular junction. Not least, the mitral valve contributes to the make up and function of the left ventricular outflow tract. The anatomical and functional interdependence between the mitral valve and the left ventricular myocardium is evident not only following their particularities of vascularization but also it is reflected in morbid states such as ischemic cardiac disease and dilated cardiomyopathy. All the new concepts and ideas, ask for a more profound study of the clinical anatomy of the mitral valve, underscoring the importance of a pertinent dialogue between specialists and by using a more appropriate and unitary terminology.     

Disturbed diurnal rhythm alters gene expression and exacerbates cardiovascular disease with rescue by resynchronization

Day/night rhythms are recognized as important to normal cardiovascular physiology and timing of adverse cardiovascular events; however, their significance in disease has not been determined. We demonstrate that day/night rhythms play a critical role in compensatory remodeling of cardiovascular tissue, and disruption exacerbates disease pathophysiology. We use a murine model of pressure overload cardiac hypertrophy (transverse aortic constriction) in a rhythm-disruptive 20-hour versus 24-hour environment. Echocardiography reveals increased left ventricular end-systolic and -diastolic dimensions and reduced contractility in rhythm-disturbed transverse aortic constriction animals. Furthermore, cardiomyocytes and vascular smooth muscle cells exhibit reduced hypertrophy, despite increased pressure load. Microarray and real-time PCR demonstrate altered gene cycling in transverse aortic constriction myocardium and hypothalamic suprachiasmatic nucleus. With rhythm disturbance, there is a consequent altered cellular clock mechanism (per2 and bmal), whereas key genes in hypertrophic pathways (ANF, BNP, ACE, and collagen) are downregulated paradoxical to the increased pressure. Phenotypic rescue, including reversal/attenuation of abnormal pathology and genes, only occurs when the external rhythm is allowed to correspond with the animals' innate 24-hour internal rhythm. Our study establishes the importance of diurnal rhythm as a vital determinant in heart disease. Disrupted rhythms contribute to progression of organ dysfunction; restoration of normal diurnal schedules appears to be important for effective treatment of disease.     

Report of the European Myeloma Network on multiparametric flow cytometry in multiple myeloma and related disorders

The European Myeloma Network (EMN) organized two flow cytometry workshops. The first aimed to identify specific indications for flow cytometry in patients with monoclonal gammopathies, and consensus technical approaches through a questionnaire-based review of current practice in participating laboratories. The second aimed to resolve outstanding technical issues and develop a consensus approach to analysis of plasma cells. The primary clinical applications identified were: differential diagnosis of neoplastic plasma cell disorders from reactive plasmacytosis; identifying risk of progression in patients with MGUS and detecting minimal residual disease. A range of technical recommendations were identified, including: 1) CD38, CD138 and CD45 should all be included in at least one tube for plasma cell identification and enumeration. The primary gate should be based on CD38 vs. CD138 expression; 2) after treatment, clonality assessment is only likely to be informative when combined with immunophenotype to detect abnormal cells. Flow cytometry is suitable for demonstrating a stringent complete remission; 3) for detection of abnormal plasma cells, a minimal panel should include CD19 and CD56. A preferred panel would also include CD20, CD117, CD28 and CD27; 4) discrepancies between the percentage of plasma cells detected by flow cytometry and morphology are primarily related to sample quality and it is, therefore, important to determine that marrow elements are present in follow-up samples, particularly normal plasma cells in MRD negative cases.     

Chromosome Aberrations Induced by Occupational Exposure to Mercury

The incidence of chromosome aberrations was studied by peripheral blood incubation (52 hr, the last 4 hr in the presence of Colcemid) using a modification of the Evans' technique in twenty-two men exposed to either vapors of metallic mercury (Group I) or organic mercury (Group II). Mercury concentrations of the work areas frequently exceeded the Maximum Allowable Concentrations in the past. During the year proceding the investigation, mercury values ranged between 0.15 and 0.44 mg/m³. None of the investigated men were poisoned, but all had had repeated increased mercury absorption with urinary eliminations reaching 890 μg/l and 896 μg/l for subjects in Groups I and II, respectively.

The incidence of chromosome aberrations was significantly higher (P < .001) in subjects exposed to mercury as compared with a control group (ten subjects) of a similar mean age. There was no statistical difference in the incidence of chromosome aberrations between men belonging to Groups I and II. Although an increase of both chromatid gaps and breaks was noticed in exposed men, the incidence did not significantly differ from controls. No chromatid interchanges were recorded and no difference between exposed and control subjects was noticed concerning the frequency of aneuploid or polyploid cells.