Dynamic Analysis of Vascular Morphogenesis Using Transgenic Quail Embryos

Background: One of the least understood and most central questions confronting biologists is how initially simple clusters or sheet-like cell collectives can assemble into highly complex three-dimensional functional tissues and organs. Due to the limits of oxygen diffusion, blood vessels are an essential and ubiquitous presence in all amniote tissues and organs. Vasculogenesis, the de novo self-assembly of endothelial cell (EC) precursors into endothelial tubes, is the first step in blood vessel formation [1]. Static imaging and in vitro models are wholly inadequate to capture many aspects of vascular pattern formation in vivo, because vasculogenesis involves dynamic changes of the endothelial cells and of the forming blood vessels, in an embryo that is changing size and shape. Methodology/Principal Findings: We have generated Tie1 transgenic quail lines Tg(tie1:H2B-eYFP) that express H2B-eYFP in all of their endothelial cells which permit investigations into early embryonic vascular morphogenesis with unprecedented clarity and insight. By combining the power of molecular genetics with the elegance of dynamic imaging, we follow the precise patterning of endothelial cells in space and time. We show that during vasculogenesis within the vascular plexus, ECs move independently to form the rudiments of blood vessels, all while collectively moving with gastrulating tissues that flow toward the embryo midline. The aortae are a composite of somatic derived ECs forming its dorsal regions and the splanchnic derived ECs forming its ventral region. The ECs in the dorsal regions of the forming aortae exhibit variable mediolateral motions as they move rostrally; those in more ventral regions show significant lateral-to-medial movement as they course rostrally. Conclusions/Significance: The present results offer a powerful approach to the major challenge of studying the relative role(s) of the mechanical, molecular, and cellular mechanisms of vascular development. In past studies, the advantages of the molecular genetic tools available in mouse were counterbalanced by the limited experimental accessibility needed for imaging and perturbation studies. Avian embryos provide the needed accessibility, but few genetic resources. The creation of transgenic quail with labeled endothelia builds upon the important roles that avian embryos have played in previous studies of vascular development

A Reversible Color Polyphenism in American Peppered Moth (Biston betularia cognataria) Caterpillars

Insect body color polyphenisms enhance survival by producing crypsis in diverse backgrounds. While color polyphenisms are often indirectly induced by temperature, rearing density, or diet, insects can benefit from immediate crypsis if they evolve polyphenisms directly induced by exposure to the background color, hence immediately deriving protection from predation. Here, we examine such a directly induced color polyphenism in caterpillars of the geometrid peppered moth (Biston betularia). This larval color polyphenism is unrelated to the genetic polymorphism for melanic phenotypes in adult moths. B. betularia caterpillars are generalist feeders and develop body colors that closely match the brown or green twigs of their host plant. We expand on previous studies examining the proximal cues that stimulate color development. Under controlled rearing conditions, we manipulated diets and background reflectance, using both natural and artificial twigs, and show that visual experience has a much stronger effect than does diet in promoting precise color matching. Their induced body color was not a simple response to reflectance or light intensity but instead specifically matched the wavelength of light to which they were exposed. We also show that the potential to change color is retained until the final (sixth) larval instar. Given their broad host range, this directly induced color polyphenism likely provides the caterpillars with strong protection from bird predation

EFFECT OF EXTENT OF ANTERIOR RESECTION AND SEX ON DISEASE-FREE SURVIVAL AND LOCAL RECURRENCE IN PATIENTS WITH RECTAL-CANCER

Results are presented following 119 curative resections for rectal cancer performed on 47 women and 72 men. Throughout the study it was policy to remove part of the female genital tract when the rectal tumour impinged on the uterus and/or the posterior vaginal wall. After a median follow-up of 7.5 years, local recurrence occurred in three of 46 women and 15 of 71 men (P=0.03). The survival rates at 5 years were 71 per cent for women (95 per cent confidence interval 56-83 per cent) and 60 per cent for men (95 per cent confidence interval 50-71 per cent) (

The anatomical substrate for a difference in surgical approach to rectal cancer in male and female patients

This review emphasizes gender related anatomical differences warranting a difference in surgical approach to the problem of rectal cancer in men and women. Differences in the anatomy of the bony pelvis, the pelvic viscera and the lymphatics of the rectum, inspired the authors to extend the margins of the rectal resection in the anterior plane in female patients. Between 1978 and 1992 a rectal resection was carried out for cancers confined to the pelvis in 158 patients. Of these patients 152 were available for review, 95 male and 57 female. In 24 out of 57 female patients extension of the rectal resection towards the genital tract by en bloc excision of posterior vaginal wall and/or uterus was considered necessary to be confident about obtaining tumour free margins. After a median follow-up of 8 years the risk of local recurrence and cancer related death were significantly lower in female patients

Endourological management of ureteral obstruction after renal transplantation

Purpose: We evaluated endourological treatment of ureteral obstruction after renal transplantation. Materials and Methods: Between January 1986 and December 1993, 582 kidney transplantations were performed at our center, and ureteral obstruction was suspected in 31 cases (5.3%). Results: Initial treatment consisted of retrograde placement of an internal stent in 6 patients and percutaneous nephrostomy in 25. Due to upper tract dilatation obstruction could not be diagnosed in 3 patients, and rejection was the cause of decreasing renal function. Obstruction was temporary in 8 of the remaining 28 patients, including 6 in whom a Double-J* stent was introduced in a retrograde manner without anesthesia. In the other 2 patients as well as the 20 with definitive obstruction, cannulation of the transplant orifice without anesthesia was unsuccessful and percutaneous nephrostomy drainage was necessary. Even with general anesthesia a guide wire could not be passed along the stricture in a retrograde or antegrade fashion in 7 of the 20 patients with definitive obstruction and open surgery was performed. The remaining 13 patients underwent dilation with (9) or without (4) diathermic incision. All 4 patients treated with dilation only had recurrent obstruction, while 9 treated with dilation and incision had no recurrence after a minimum followup of 27 months (mean 58). Conclusions: Modern endourological procedures have replaced open reconstructive surgery in the majority of patients with ureteral obstruction after renal transplantation

Cytogenetic support for primacy prostatic cancer in a patient presenting with a soft tissue mass in the leg

A 65-year-old man presented with a soft tissue mass in the leg, clinically suspect of a sarcoma. Histologic examination suggested a metastatic adenocarcinoma of the prostate, which could not be confirmed by immunohistologic studies. However, cytogenetic analysis strongly supported this diagnosis. A primary prostatic carcinoma was indeed found and the patient died of widely disseminated disease. These findings illustrate the significance of chromosomal analysis in the search for a primary tumor in patients with an unknown primary