Vocalizations associated with pectoral fin contact in bottlenose dolphins (Tursiops truncatus).

Pectoral fin contact in bottlenose dolphins represents one form of tactile communication. Acoustic communication associated with pectoral fin contact is an additional level of communication that may change or enhance the tactile message between two individuals. In this study, we examine vocalization types associated with pectoral fin contact in a group of captive bottlenose dolphins (Tursiops truncatus). From 2006 to 2009, vocalizations potentially associated with 748 pectoral fin contacts were examined: whistles, click trains and overlap of whistles and click trains were documented when associated with fin contact. Dolphins were also documented not vocalizing when exchanging pectoral fin contacts. Call type associated with pectoral fin contact was compared for the proportion of the type of pectoral fin contact, vocalizer sex, initiator and receiver roles, and gender pair. Overall, vocalizations differed significantly by vocalizer role as rubber or rubbee, initiator, and sex. Receivers and rubbees clicked and used overlap vocalizations more frequently, and males produced overlap vocalizations more frequently. These results suggest that whistles may be used to initiate pectoral fin contact or show preference for a particular partner, while click trains may be used to show disinterest in pectoral fin contact or to signal the end of a contact. Examining vocalizations produced in conjunction with tactile contact is a relatively new approach in the study of individual dolphin behavior and may be useful for understanding dolphin social alliances and social preferences for various individuals within a population.

The experimental study of polyelectrolyte coatings suitability for encapsulation of cells.

Living cells encapsulated in polymeric shells are receiving increasing attention because of their possible biotechnological and biomedical applications. The aim of this work is to evaluate how different polyelectrolyte coatings, characterized by different numbers of polyelectrolyte layers and by different polyelectrolyte conformations, affect the viability of encapsulated biological material. We demonstrate the ability to individually encapsulate HL-60 cells as well as rat pancreatic islets within polymeric shells consisting of different PE layers using the layer-by-layer process. Coating of HL-60 cells allows for surviving and functioning of cells for all applied PE as well as for different numbers of layers. The islets encapsulated in applied polyelectrolytes exhibited the lower level of mitochondrial activity as compared to non-encapsulated islets. Nevertheless, encapsulated islets exhibited comparable absorbance values during the whole period of culture. Polyelectrolyte coating seems to be a promising way of allowing capsule void volume minimization in a model of encapsulated biological material for local production of biologically active substances.

Analysis of postural sway in patients with normal pressure hydrocephalus: effects of shunt implantation.

Poor postural balance is one of the major risk factors for falling in normal pressure hydrocephalus (NPH). Postural instability in the clinic is commonly assessed based upon force platform posturography. In this study we focused on the identification of changes in sway characteristics while standing quiet in patients with NPH before and after shunt implantation. Postural sway area and sway radius were analyzed in a group of 9 patients and 46 controls of both genders. Subject's spontaneous sway was recorded while standing quiet on a force platform for 30-60 s, with eyes open and then closed. Both analyzed sway descriptors identified between-group differences and also an effect of shunt implantation in the NPH group. Sway radius and sway area in patients exhibited very high values compared with those in the control group. Importantly, the effect of eyesight in patients was not observed before shunt implantation and reappeared after the surgical treatment. The study documents that static force platform posturography may be a reliable measure of postural control improvement due to shunt surgery.

Recognition of gait disturbances in patients with normal pressure hydrocephalus using a computer dynography system.

Gait and body balance disturbances are important clinical problems in patients with normal pressure hydrocephalus (NPH). They affect patients' locomotion and lead to a higher risk of falls. The gait pattern may be described as durations of the single and double support and of a stance phase. The aim of the present study was to apply the pattern recognition methods for the evaluation of gait disturbances in patients with NPH before and after neurosurgical treatment (shunt implantation). The results indicate that the parameters measured with a Computer DynoGraphy (CDG) system may effectively differentiate changes of gait in patients with NPH.

Three-dimensional culture of hepatocytes on spongy polyethersulfone membrane developed for cell transplantation.

Implantable bioartificial liver has been investigated for patients suffering from liver insufficiency after mass liver resection or acute liver failure. Liver cells are implanted as free cell suspension, in microencapsulation systems or using microcarriers. To exhibit their typical functions, hepatic cells need a three-dimensional environment that is much more physiological than a flat one. The aim of our study was in vivo evaluation of spongy polyethersulfone membranes as a synthetic support for hepatic cells grown three dimensionally and transplanted to SCID/NOD mice. Spongy membranes were prepared using phase inversion from membrane-forming mixtures containing the following: polyethersulfone (based polymer), dimethylformamide (solvent), polyvinylpyrrolidone MW 10000 (small pore precursor), and cellulose (large pore precursor). We observed that polyethersulfone membranes were well tolerated by C3A cells and we did not observe any toxic effect, resulting in viability of cells >95%. Use of collagen gel as a support for cells on the scaffold gives the opportunity to increase 10 times the number of cells seeded on the membrane. Heparin addition to collagen gel did not influence albumin production in SCID/NOD mice. We observed an increase of albumin production after 7 and 14 days after implantation. Use of collagen gels in combination with polymer scaffolds allows preparation of bioartificial organs possessing high cell concentration for transplantation purposes.

A technique for the combination of clearing, staining, and injecting small mammals.

A combined method for clearing soft tissues, staining cartilage and bone, and injecting the vascular system of small mammals was developed using Mus musculus (house mouse). Mammalian muscle tissue remains milky or even opaque after "clearing" by previous techniques due to the relatively high content of intramuscular fat. A method employing chloroform-ethanol successfully renders soft tissues of mammalian specimens translucent without damaging or bleeding color from the latex injected in the circulatory system. Resulting specimens yield an excellent view of the skeletal system and the injected vascular system without obstruction by opaque tissues or disruption by physical removal of connective tissue.

[Creating models of the development of a computer-assisted system of cardiovascular services]. / Generowanie scenariuszy rozwoju systemu opieki kardiologicznej wspomagane komputerem.

In the paper computer aided method is described which can be applied for scenario generation of the health care system for cardiovascular diseases treatment. The real life system is represented in the form of patient flows in the network of diagnostic and therapeutic medical services. The adequate computer system with certain requirements for input data is then prepared. The alternative projections can be automatically calculated and evaluated by the expert teams for scenario generation. Selected preliminary scenarios obtained for ischemic heart disease are presented.