Lymphatic drainage from the skin of the back to retroperitoneal and paravertebral lymph nodes in melanoma patients

Background: Preoperative lymphoscintigraphy (LS) with^99mTc antimony sulphide colloid is now part of the routine management of patients with intermediate thickness melanoma at the Sydney Melanoma Unit. Over a 13-year period, 1375 patients have been examined using LS, and we have observed many unusual lymphatic drainage pathways, including direct drainage through the body wall to retroperitoneal and paravertebral lymph nodes from the skin of the back. The aim of this study was to determine the incidence of such drainage in the 542 patients who had primary melanoma sites on the posterior trunk. Methods: The lymphoscintigrams performed on these patients were examined for the presence of direct lymphatic drainage through the posterior body wall to sentinel nodes in the retroperitoneal and paravertebral regions. Results: Lymphatic drainage directly through the body wall to such lymph nodes occurred in 14 of these 542 patients. Conclusions: Preoperative knowledge of the presence of this lymph drainage pattern may influence surgical management, and follow-up investigations in these patients can be tailored to ensure that the relevant areas are examined with anatomic imaging or F18-FDG PET scans.     

Synthesis and Antitumour Activity of New Derivatives of Flavone-8-acetic Acid (FAA). Part 1: 6-Methyl Derivatives

A range of 17 derivatives of flavone-8-acetic acid (FAA) with a 6-methyl substituent have been prepared and their anti-tumour activity evaluated in vitro against a panel of human and murine tumour cell lines and in vivo against MAC 15A. While many of the compounds show activity comparable to FAA in vitro, this essentially disappears in vivo, possibly due to degradation before the compounds can reach the tumour site.     

Maternal satisfaction following post-shelter family reunification

The purpose of this study was to examine the correlates of post-shelter maternal family satisfaction in a group of youth who were reunified with their families following a shelter stay. Findings indicated that higher ratings of family satisfaction were related to greater maternal problem solving skill and less family conflict.     

A monitoring,feedback, and triggering system for reproducible breath-hold MR imaging

A technique is described that provides improved reproducibility of breath-holding for MR image acquisition by monitoring the superior-inferior (S/I) position of the diaphragm. The method incorporates detection of the level of inspiration using an MR signal, rapid display to the patient of diaphragm position to enable breath-hold adjustment, and triggering of image data acquisition once appropriate position is attained. The response time of the system is short, approximately 10 ms. Studies in six volunteers using this method demonstrate a considerable decrease in the S/I range of diaphragm position over 10 consecutive periods of suspended respiration. The mean range is 1.3 mm with the system, while it is 8.3 mm without using it is expected that this method will be of assistance in many abdominal and cardiothoracic studies that use breath-hold techniques.     

Preparation of metaphase chromosomes in cell cultures derived from an aquatic reptile

Summary Cell cultures (GTS) of epithelioid nature derived from the skin of a green sea turtle,Chelonia mydas, were treated with colchicine at a final concentration of 0.5 g/ml for 16 h. Mitotic cells were harvested by brief treatment with trypsin-Versene, subjected to hypotonic solution (1% sodium citrate) and fixed in (13) acetic acid: methanol. Giemsa stained preparations were photographed on High Contrast Copy film under phase contrast optics using a bluegreen filter. The result was significant enhancement of the microchromosome portion of the complement morphologically characteristic of reptilian metaphase chromosomes. By this method it was determined that the GTS cell line retains the female diploid number of the Chelonia species.     

Relating cell and tissue mechanics: Implications and applications

The Differential Adhesion Hypothesis (DAH) posits that differences in adhesion provide the driving force for morphogenetic processes. A manifestation of differential adhesion is tissue liquidity and a measure for it is tissue surface tension. In terms of this property, DAH correctly predicts global developmental tissue patterns. However, it provides little information on how these patterns arise from the movement and shape changes of cells. We provide strong qualitative and quantitative support for tissue liquidity both in true developmental context and in vitro assays. We follow the movement and characteristic shape changes of individual cells in the course of specific tissue rearrangements leading to liquid-like configurations. Finally, we relate the measurable tissue-liquid properties to molecular entities, whose direct determination under realistic three-dimensional culture conditions is not possible. Our findings confirm the usefulness of tissue liquidity and provide the scientific underpinning for a novel tissue engineering technology. Developmental Dynamics 237:2438-2449, 2008. (c) 2008 Wiley-Liss, Inc.     

A critique of impedance measurements in cardiac tissue

The specific impedance of cardiac tissue cannot be measured directly. Instead, the investigator obtains voltage and current measurements and places them into a model of the tissue's structure to infer the impedances of elements of the model. If the model fails to describe major aspects of the real tissue, the results may be worthless, although possibly self-consistent. In the literature of impedance measurement in cardiac tissue, only rarely is the model explicitly described; more commonly, the tissue model is adopted implicitly when equations giving the impedance in terms of voltage and current measurements are adopted. This paper examines the series of models that have been used in specific impedance measurements of cardiac tissue and shows how the same or similar measurements can accurately describe tissue impedivity or can lead to significant errors when inadequate models such as isotropic and anisotropic monodomains (although a part of work of historical merit) are used.     

Structural changes induced in scallop heavy meromyosin molecules by Ca2+ and ATP

Summary We have used physicochemical and ultrastructural methods to investigate the effects of Ca²⁺ and ATP on the structure of purified heavy meromyosin (HMM) from the striated adductor muscle of the scallop, a species with myosin-linked regulation. Using papain as a structural probe, we found that, in the presence of ATP, the head/tail junction was five times more susceptible to digestion at high levels of Ca²⁺ than at low levels.wBy HPLC gel filtration, two fractions of scallop HMM with different Stokes radii were detected in the presence of ATP at low Ca²⁺, while at high Ca²⁺ a single peak with the larger Stokes radius predominated. Electron microscopy of rotary-shadowed HMM suggested that molecules with the smaller Stokes radius had their heads bent back towards their tails, while those with the larger radius had heads pointing away from the tail. The number of molecules with their heads bent back decreased at high Ca²⁺ levels. The data also showed that in the absence of ATP or at high salt, HMM molecules behaved similarly to those in the presence of ATP at high Ca²⁺.These results suggest that scallop myosin heads can exist in two conformations (heads down towards the tail and heads up away from the tail) and that the equilibrium between these two conformations is altered by the concentrations of salt, ATP and Ca²⁺. However, the equilibrium between the two forms appears to be too slow to be involved in regulating contraction. The heads-down configuration may instead be related to the inactive, folded (10S) form of scallop myosin and possibly involved in filament assembly during development.