Adhesion of human ovarian adenocarcinoma IGROV1 cells to endothelial cells is partly mediated by the alphav integrins-vitronectin adhesive system and induces an alteration of endothelial integrity

Several lines of evidence suggest that vascularization plays an important role in the growth, local expansion and dissemination of ovarian epithelial tumours. However, the interaction of ovarian carcinoma cells with the endothelium remains poorly understood. To investigate adhesive events underlying this process, we used an in vitro model of cocultures between the IGROV1 human ovarian adenocarcinoma cell line and human umbilical vein endothelial cells (HUVECs). IGROV1 cells were shown to adhere rapidly on the HUVECs monolayer. Adhesion was inhibited by anti-alphav integrin and anti-Vn blocking antibodies, but not by anti-beta1 integrin antibodies. Anchorage of carcinoma cells led to the rupture of endothelial integrity, as revealed by the formation of holes in the monolayer and by the disappearance of the interendothelial VE-Cadherin network. Considering the ability of ovarian carcinoma to disseminate by a haematogenous way, these in vitro events could mimic a preliminary step for carcinoma cells crossing the endothelial barrier to extravasate.     

Empty Nest: A Case Study of Maternal Response to Separation From a Juvenile Offspring in a Captive Sumatran Orangutan (Pongo pygmaeus abelii)

Improving the welfare of captive nonhuman primates requires evaluating the stressors created by the captive environment and reducing their negative effects. Social separation, although sometimes necessary for managing the genetic diversity of captive populations of animals, causes both psychological and physiological stress in human and primate monkey infants. Few studies have examined the maternal response of great ape mothers to separation from their offspring. This article describes the behavioral changes of a mother orangutan (Pongo pygmaeus abelii) after separation from her juvenile daughter. We collected data on measures of proximity and social behavior before the separation of the mother-infant dyad and of locomotion, arboreality, abnormal behavior, solitary behavior, and vocalization both before and after separation. We observed no behavioral indications of protest but observed some indications of despair after separation: decreased locomotion, increased inactivity, and increased self-directed behavior. In addition, we observed increases in arboreality and object-oriented behavior during morning sessions. These findings suggest that mother-juvenile separation in orangutans might be less stressful for mothers than might be expected. Such research has implications for the welfare and management of captive animals.     

Failure of a chemical spray to significantly reduce stereotypic licking in a captive giraffe

The repetitive licking of nonfood substrates is a common stereotypic behavior in captive giraffes. In this study we attempted to reduce stereotypic licking in a Masai giraffe (Giraffa camelopardalis tippelskirchi) by applying a bitter chemical (marketed as a taste deterrent to prevent the unwanted licking and chewing of substrates) to the areas of the fence licked most frequently by the giraffe. We hypothesized that this treatment would reduce stereotypic licking. However, there were no significant overall changes in stereotypic licking following treatment with the chemical spray. Although licking of the treated area was observed to decrease, the behavior increased in nontreated areas. These results suggest that the underlying motivation driving the behavior was not affected by the aversive stimulus. Because stereotypic licking in giraffes may be based on a motivation to use their tongues in foraging, more effective techniques for reducing stereotypic fence‐licking in giraffes may include increasing feeding duration by increasing the quantity, processing time, or distribution range of food. Zoo Biol 22:601–607, 2003. © 2003 Wiley‐Liss, Inc.     

Androgen Function in “Psychogenic” and “Constitutional” Types of Impotence

Androgen function was studied in twenty-five physically healthy “primarily” impotent males classified on clinical criteria into “psychogenic” or “constitutional” groups. The mean urinary testosterone level in the former was significantly higher than in the latter group (P<0·005). Important variables associated significantly with higher urinary testosterone levels (P<0·05) were (a) “late onset” impotence, (b) shorter duration than two years, (c) stronger “sex drive,” and (d) an alternative sexual outlet to orgasm and ejaculation in the three months preceding referral; the last-mentioned appeared to be the single most important discriminatory feature.It is suggested that testosterone excretion patterns—namely, high, average, and low—may be one method of classifying impotence.     

Space shuttle flight (STS-45) of L8 myoblast cells results in the isolation of a nonfusing cell line variant

Myoblast cell cultures have been widely employed in conventional (1g) studies of biological processes because characteristics of intact muscle can be readily observed in these cultured cells. We decided to investigate the effects of spaceflight on muscle by utilizing a well characterized myoblast cell line (L8 rat myoblasts) as cultured in the recently designed Space Tissue Loss Flight Module “A” (STL-A). The STL-A is a “state of the art,” compact, fully contained, automated cell culture apparatus which replaces a single mid-deck locker on the Space Shuttle. The L8 cells were successfully flown in the STL-A on the Space Shuttle STS-45 mission. Upon return to earth, reculturing of these spaceflown L8 cells (L8SF) resulted in their unexpected failure to fuse and differentiate into myotubes. This inability of the L8SF cells to fuse was found to be a permanent phenotypic alteration. Scanning electron microscopic examination of L8SF cells growing at 1g on fibronectin-coated polypropylene fibers exhibited a strikingly different morphology as compared to control cells. In addition to their failure to fuse into myotubes, L8SF cells also piled up on top of each other. When assayed in fusion-promoting soft agar, L8SF cells gave rise to substantially more and larger colonies than did either preflight (L8AT) or ground control (L8GC) cells. All data to this point indicate that flying L8 rat myoblasts on the Space Shuttle for a duration of 7–10 d at subconfluent densities results in several permanent phenotypic alterations in these cells. © 1994 Wiley-Liss, Inc.     

Engineered cardiac tissues

Cardiac tissue engineering offers the promise of creating functional tissue replacements for use in the failing heart or for in vitro drug screening. The last decade has seen a great deal of progress in this field with new advances in interdisciplinary areas such as developmental biology, genetic engineering, biomaterials, polymer science, bioreactor engineering, and stem cell biology. We review here a selection of the most recent advances in cardiac tissue engineering, including the classical cell-scaffold approaches, advanced bioreactor designs, cell sheet engineering, whole organ decellularization, stem cell-based approaches, and topographical control of tissue organization and function. We also discuss current challenges in the field, such as maturation of stem cell-derived cardiac patches and vascularization.     

The external PASTA domain of the essential serine/threonine protein kinase PknB regulates mycobacterial growth

PknB is an essential serine/threonine protein kinase required for mycobacterial cell division and cell-wall biosynthesis. Here we demonstrate that overexpression of the external PknB_PASTA domain in mycobacteria results in delayed regrowth, accumulation of elongated bacteria and increased sensitivity to β-lactam antibiotics. These changes are accompanied by altered production of certain enzymes involved in cell-wall biosynthesis as revealed by proteomics studies. The growth inhibition caused by overexpression of the PknB_PASTA domain is completely abolished by enhanced concentration of magnesium ions, but not muropeptides. Finally, we show that the addition of recombinant PASTA domain could prevent regrowth of Mycobacterium tuberculosis, and therefore offers an alternative opportunity to control replication of this pathogen. These results suggest that the PknB_PASTA domain is involved in regulation of peptidoglycan biosynthesis and maintenance of cell-wall architecture.