bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of low environmental salinity on plasma composition and renal function of the Atlantic stingray, a euryhaline elasmobranch
Authors: Janech Michael G. , Fitzgibbon Wayne R. , Ploth David W. , Lacy Eric R. , Miller Donald H.
Published: April 2006

Marine elasmobranchs maintain internal osmolality higher than their external environment, resulting in an osmotic gradient for branchial water uptake. This gradient is markedly increased in low-salinity habitats. The subsequent increase in water uptake presents a challenge to volume homeostasis. The Atlantic stingray is a marine elasmobranch that inhabits a remarkable range of environmental salinities. We hypothesized that the ability of these stingrays to regulate fluid volume in low-salinity environments is due primarily to a renal glomerular and tubular functional reserve. We tested this hypothesis by measuring renal excretory function after a rapid and sustained 50% reduction in the osmolality of the external medium. Atlantic stingrays were maintained in harbor water [control salinity (CS) ∼850 mosmol/kgH2O] for 1 wk. Rays were then either transferred to diluted harbor water [low salinity (LS) ∼440 mosmol/kgH2O] or maintained in CS for a further 24 h. Renal excretory function was markedly higher in the rays subjected to low salinity. Glomerular filtration rate was threefold higher and urine flow rate ninefold higher in the LS group. The clearance of solute-free water was greater, and solute-free water comprised a significantly larger proportion of the urine output for the stingrays transferred to dilute harbor water. We conclude that 1) the kidneys of Atlantic stingrays have a remarkable glomerular and tubular functional reserve, and 2) the marked increase in renal function attenuates the increase in fluid volume when these fish move into low-salinity habitats.
Altered phenotype of cultured urothelial and other stratified epithelial cells: implications for wound healing
Authors: Sun Tung-Tien
Published: April 2006

The differentiation of cultured stratified epithelial cells can deviate significantly from that of normal epithelium, leading to suggestions that cultured cells undergo abnormal differentiation, or a truncated differentiation. Thus cultured epidermal and corneal epithelial cells stop synthesizing their tissue-specific keratin pair K1/K10 and K3/K12, respectively. The replacement of these keratins in the suprabasal compartment by K6/K16 keratins that are made by all stratified squamous epithelia during hyperplasia rules out a truncated differentiation. Importantly, the keratin pattern of in vivo corneal epithelium undergoing wound repair mimics that of cultured rabbit corneal epithelial cells. Although cultured urothelial cells continue to synthesize uroplakins, which normally form two-dimensional crystalline urothelial plaques covering almost the entire apical urothelial surface, these proteins do not assemble into crystals in cultured cells. Cultured epithelial cells can, however, rapidly regain normal differentiation on the removal of mitogenic stimuli, the use of a suitable extracellular matrix, or the transplantation of the cells to an in vivo, nonmitogenic environment. These data suggest that cultured epithelial cells adopt altered differentiation patterns mimicking in vivo regenerating or hyperplastic epithelia. Blocking the synthesis of tissue-specific differentiation products, such as the K1 and K10 keratins designed to form extensive disulfide cross-links in cornified cells, or the assembly of uroplakin plaques allows epithelial cells to better migrate and proliferate, activities that are of overriding importance during wound repair. Cultured urothelial and other stratified epithelial cells provide excellent models for studying the regulation of the synthesis and assembly of differentiation products, a key cellular process during epithelial wound repair.
Sex differences in heat shock protein 72 expression and localization in rats following renal ischemia-reperfusion injury
Authors: Fekete Andrea , Vannay Ádám , Vér Ágota , Rusai Krisztina , Müller Veronika , Reusz György , Tulassay Tivadar , Szabó Attila J.
Published: April 2006

Previously, we demonstrated gender differences in Na-K-ATPase (NKA) expression and function after renal ischemia-reperfusion (I/R) injury (Sex differences in the alterations of Na+, K+-ATPase following ischemia-reperfusion injury in the rat kidney. J Physiol 555: 471–480, 2004). Postischemic membrane destruction causes inhibition of NKA, whereas heat shock protein (HSP) 72 helps to preserve it. We tested the sex differences in postischemic expression of HSP72 and colocalization with NKA. The left renal pedicle of uninephrectomized female (F) and male (M) Wistar rats was clamped for 55 min followed by 2 (T2), 16 (T16), and 24 h (T24) of reperfusion. Uninephrectomized, sham-operated F and M rats served as controls. Postischemic blood urea nitrogen (BUN), serum creatinine, and renal histology were analyzed. HSP72 mRNA expression was detected by RT-PCR, protein levels by Western blot analysis. Fluorescent immunohistochemistry was performed to evaluate the localization of HSP72 and NKA α1-subunit. Postischemic BUN and creatinine were higher, and renal histology showed more rapid progression in M vs. F ( P < 0.05). HSP72 mRNA expression was higher in F vs. M in control and in all I/R groups ( P < 0.05). Similar changes were observed in HSP72 protein levels (F vs. M, P < 0.05, control, T2, T16, T24, respectively). Immunohistochemical localization of HSP72 and NKA α1was similar in control F and M. In postischemic F kidneys, the majority of NKA α1and HSP72 was colocalized on the basolateral membrane of tubular cells, whereas in M prominent staining was observed in the cytosol and apical domain. This study indicates that in female kidneys the higher basal and postischemic levels of HSP72 and different colocalization with NKA might contribute to the gender differences in renal I/R injury.
More than colocalizing with polycystin-1, polycystin-lis in the centrosome
Authors: Bui-Xuan Eva-Flore , Li Qiang , Chen Xing-Zhen , Boucher Catherine A. , Sandford Richard , Zhou Jing , Basora Nuria
Published: April 2006

Polycystin-1 and polycystin-2 are involved in autosomal dominant polycystic kidney disease by unknown mechanisms. These two proteins are located in primary cilia where they mediate mechanosensation, suggesting a link between cilia function and renal disease. In this study, we sought to characterize the subcellular localization of polycystin-l, a closely related member of polycystin-2, in epithelial renal cell lines. We have shown that endogenous polycystin-l subcellular distribution is different in proliferative and nonproliferative cultures. Polycystin-l is found mostly in the endoplasmic reticulum in subconfluent cell cultures, while in confluent cells it is redistributed to sites of cell-cell contact and to the primary cilium as is polycystin-1. Subcellular fractionation confirmed a common distribution of polycystin-l and polycystin-1 in the fractions corresponding to those containing the plasma membrane of postconfluent cells. Reciprocal coimmunoprecipitation experiments showed that polycystin-l was associated with polycystin-1 in a common complex in both subconfluent and confluent cell cultures. Interestingly, we also identified a novel site for a polycystin member (polycystin-l) in unciliated cells, the centrosome, which allowed us to reveal an involvement of polycystin-l in cell proliferation.
Pioglitazone mitigates renal glomerular vascular changes in high-fat, high-calorie-induced type 2 diabetes mellitus
Authors: Rodriguez Walter E. , Tyagi Neetu , Joshua Irving G. , Passmore John C. , Fleming John T. , Falcone Jeff C. , Tyagi Suresh C.
Published: April 2006

Our hypothesis is that impairment of peroxisome proliferator-activated receptor-γ (PPARγ) initiates renal dysfunction by increasing renal glomerular matrix metalloproteinase-2 (MMP-2) activity because of increased renal homocysteine (Hcy) and decreased nitric oxide (NO) levels. C57BL/6J mice were made diabetic (D) by being fed a high-fat-calorie diet, and an increase in PPARγ activity was induced by adding pioglitazone (Pi) to the diet. Mice were grouped as follows: normal calorie diet (N), D, N+Pi, and D+Pi ( n = 6/group). The glomerular filtration rate (GFR), renal artery blood flow and pressure, and plasma glucose were measured. Renal glomeruli and preglomerular arterioles were isolated. Plasma and glomerular levels of NO, Hcy, and MMP activity were measured. The contractile response to phenylephrine and the dilatation response to acetylcholine in renal arteriolar rings were measured in a tissue myobath. In N, D, N+Pi, and D+Pi groups, respectively, GFR was 9.4 ± 1.2, 3.9 ± 1.1, 9.2 ± 1.6, and 8.4 ± 1.4 μl·min−1·g body wt−1. Renovascular resistance was 140 ± 3, 367 ± 21, 161 ± 9, and 153 ± 10 mmHg·ml·min−1. Levels of Hcy were increased from 5.8 ± 1.5 in the N to 18.0 ± 4.0 μmol/l in the D group. Glomerular levels of MMP-2 were increased in D mice compared with N mice, and there was no change in levels of MMP-9. Treatment with Pi ameliorated glomerular levels of MMP-2 and Hcy in the D group. Renal artery ring contraction and relaxation by phenylephrine and acetylcholine, respectively, were attenuated in the D groups compared with the N groups. Results suggest that a PPARγ agonist ameliorates preglomerular arteriole remodeling in diabetes by decreasing tissue levels of Hcy and MMP-2 activity and increasing NO.
Gαq-dependent signaling cascades stimulate water-seeking behavior
Authors: Wang Liming , Flannery Patrick J. , Athirakul Krairerk , Dunn Stephen R. , Kourany Wissam M. , Spurney Robert F.
Published: April 2006

We used the mouse nephrin promoter to express a constitutively active Gαq [Gαq(Q>L)] transgene in mice. As previously reported, the transgene was expressed in kidney, pancreas, and brain, and the kidney phenotype was characterized by albuminuria and reduced nephron mass. Additional studies revealed a second phenotype characterized by polyuria and polydipsia. The polyuric phenotype was not caused by abnormal glucose metabolism or hypercalcemia but was accompanied by reduced urinary concentrating ability. Additional studies found that 1) water restriction was associated with an appropriate increase in serum vasopressin levels in transgenic (TG) mice; 2) the urinary concentrating defect was not corrected by administration of desamino-d-arginine vasopressin (DDAVP); and 3) papillary length was similar in TG and non-TG mice. To examine the renal response to DDAVP at the molecular level, we monitored aquaporin 2 (AQP2) and vasopressin V2 receptor (V2R) mRNA levels in mouse kidney. Consistent with the known effects of vasopressin, administration of DDAVP caused a decrease in V2R mRNA levels and an increase in AQP2 mRNA levels in both TG and non-TG animals, suggesting an appropriate renal response to DDAVP in the TG mice. To determine whether the urine concentrating abnormality was the result of primary polydipsia, water intake by TG mice was restricted to the amount ingested by non-TG animals. After 5 days, urinary concentrating ability was similar in TG mice and non-TG littermate controls. These data are consistent with the notion that expression of the Gαq(Q>L) transgene in the brain induced primary polydipsia in the TG mice.
Hippocampal Sharp Wave-Ripples Linked to Slow Oscillations in Rat Slow-Wave Sleep
Authors: Mölle Matthias , Yeshenko Oxana , Marshall Lisa , Sara Susan J. , Born Jan
Published: April 2006

Slow oscillations originating in the prefrontal neocortex during slow-wave sleep (SWS) group neuronal network activity and thereby presumably support the consolidation of memories. Here, we investigated whether the grouping influence of slow oscillations extends to hippocampal sharp wave-ripple (SPW) activity thought to underlie memory replay processes during SWS. The prefrontal surface EEG and multiunit activity (MUA), along with hippocampal local field potentials (LFP) from CA1, were recorded in rats during sleep. Average spindle and ripple activity and event correlation histograms of SPWs were calculated, time-locked to half-waves of slow oscillations. Results confirm decreased prefrontal MUA and spindle activity during EEG slow oscillation negativity and increases in this activity during subsequent positivity. A remarkably close temporal link was revealed between slow oscillations and hippocampal activity, with ripple activity and SPWs being also distinctly decreased during negative half-waves and increased during slow oscillation positivity. Fine-grained analyses of temporal dynamics revealed for the slow oscillation a phase delay of approximately 90 ms with reference to up and down states of prefrontal MUA, and of only approximately 60 ms with reference to changes in SPWs, indicating that up and down states in prefrontal MUA precede corresponding changes in hippocampal SPWs by approximately 30 ms. Results support the notion that the depolarizing surface-positive phase of the slow oscillation and the associated up state of prefrontal excitation promotes hippocampal SPWs via efferent pathways. The preceding disfacilitation of hippocampal events temporally coupled to the negative slow oscillation half-wave appears to serve a synchronizing role in this neocorticohippocampal interplay.
Galanin Modulates Neuronal and Synaptic Properties in the Rat Supraoptic Nucleus in a Use and State Dependent Manner
Authors: Kozoriz Michael G. , Kuzmiski J. Brent , Hirasawa Michiru , Pittman Quentin J.
Published: April 2006

The magnocellular neurons of the hypothalamic supraoptic nucleus (SON) synthesize and secrete oxytocin (OXT) and vasopressin (AVP) from their dendrites. These peptides, and several other neurotransmitters, have been shown to modulate afferent glutamatergic neurotransmission in the SON. The neuropeptide, galanin (GAL) is also localized in SON magnocellular neurons and in afferent fibers in the nucleus. We show that GAL dose-dependently reduces evoked excitatory postsynaptic currents (eEPSCs), alters paired pulse ratio and decreases mEPSC frequency, but not amplitude or decay kinetics in both OXT and AVP neurons. GAL therefore modulates excitatory neurotransmission at a likely presynaptic receptor. Neither OXT/AVP, GABAB nor cannabinoid antagonists blocked this effect. A GAL2/3 agonist mimicked GAL's action while GAL1 antagonist did not block GAL’s effect, suggesting that GAL2/3 receptors mediate the presynaptic effect. In nondehydrated rats GAL causes a small postsynaptic response, as assessed by input resistance measurements. When the rats were water deprived for 2 days the presynaptic response to GAL was unaltered; however, the postsynaptic decrease in input resistance and hyperpolarization was increased, an effect consistent with a previously described increase in GAL1 receptor expression in dehydration. A GAL1 receptor antagonist blocked the postsynaptic effects. Last, when a train of eEPSCs was elicited, GAL was found to inhibit the earlier events in a train but not the latter. This indicates that GAL may modulate a single synaptic event more effectively than trains of synaptic inputs, thereby acting as a high-pass filter.
Novel subcellular locations and functions for secretory pathway Ca2+/Mn2+-ATPases
Authors: Southall Tony D. , Terhzaz Selim , Cabrero Pablo , Chintapalli Venkateswara R. , Evans Jennifer M. , Dow Julian A. T. , Davies Shireen-Anne
Published: April 2006

Secretory pathway Ca2+/Mn2+-ATPases (SPCAs) are important for maintenance of cellular Ca2+and Mn2+homeostasis, and, to date, all SPCAs have been found to localize to the Golgi apparatus. The single Drosophila SPCA gene ( SPoCk) was identified by an in silico screen for novel Ca2+-ATPases. It encoded three SPoCk isoforms with novel, distinct subcellular specificities in the endoplasmic reticulum (ER) and peroxisomes in addition to the Golgi. Furthermore, expression of the peroxisome-associated SPoCk isoform was sexually dimorphic. Overexpression of organelle-specific SPoCk isoforms impacted on cytosolic Ca2+handling in both cultured Drosophila cells and a transporting epithelium, the Drosophila Malpighian (renal) tubule. Specifically, the ER isoform impacted on inositol ( 1 , 4 , 5 )-trisphosphate-mediated Ca2+signaling and the Golgi isoform impacted on diuresis, whereas the peroxisome isoform colocalized with Ca2+“spherites” and impacted on calcium storage and transport. Interfering RNA directed against the common exons of the three SPoCk isoforms resulted in aberrant Ca2+signaling and abolished neuropeptide-stimulated diuresis by the tubule. SPoCk thus contributed to both of the contrasting requirements for Ca2+in transporting epithelia: to transport or store Ca2+in bulk without compromising its use as a signal.
Genomic organization, promoter activity, and expression of the human choline transporter-like protein 1
Authors: Yuan Zongfei , Tie Angela , Tarnopolsky Mark , Bakovic Marica
Published: April 2006

Choline transporter-like (CTL) proteins of the CTL1 family are novel transmembrane proteins implicated in choline transport for phospholipid synthesis. In this study, we characterized the 5′-flanking region of the human (h)CTL1 gene and examined some of the possible mechanisms of its regulation, including promoter activity, splicing, and expression. The transcription start site of the hCTL1 gene was mapped by 5′-rapid amplification of cDNA ends (RACE), and the presence of two splice variants, hCTL1a and hCTL1b, was investigated using isoform-specific PCR and 3′-RACE. The hCTL1 promoter region of ∼900 bp was isolated from MCF-7 human breast cancer cells. The promoter was TATA-less and driven by a long stretch of GC-rich sequence in accordance with widespread expression of hCTL1 at both mRNA and protein levels. Deletion analyses demonstrated that a very strong promoter is contained within 500 bp of the transcription start site, and more upstream regions did not increase its activity. The core promoter that conferred the minimal transcription is within the −188/+27-bp region, and its activity varied in human breast cancer and mouse skeletal muscle cells. Multiple motifs within the promoter regulatory region bound nuclear factors from both cultured cells and normal human skeletal muscle. The motifs within the three regions [S1 (−92/−61 bp), S2 (−174/−145 bp), and S3 (−289/−260 bp)] contained overlapping binding sites for hematopoietic transcription factors and ubiquitous transcription factors, in line with the expected gene function. Genomic analyses demonstrated a high conservation of hCTL1 and mouse CTL1 proximal promoters. Accordingly, mRNA profiles demonstrated that human splice variants were expressed ubiquitously, as demonstrated for the mouse transcripts; however, they differed from the profiles of rat CTL1 transcripts, which were more restricted to neurons and intestinal tissues. The shorter hCTL1b variant contained the cytosolic COOH-terminal motif L651KKR654for endoplasmic reticulum retrieval/retention. This retention signal was conserved in hCTL1b and rat and mouse CTL1b and is typical for transmembrane proteins of type 1 topology.
Arboreal Locomotion in Wild Black-and-White Snub-Nosed Monkeys (Rhinopithecus bieti)
Authors: Isler Karin , Grüter Cyril C.
Published: April 2006

This paper presents spatiotemporal gait parameters of arboreal locomotion in the colobine Rhinopithecus bieti in its natural habitat. While adult females used exclusively either extended-elbow vertical climbing or pulse climbing, the much larger adult males preferred the less demanding flexed-elbow vertical climbing on thin trees or on trunks with handholds. If sex-specific differences are taken into consideration, the differences between flexed-elbow and extended-elbow vertical climbing in Rhinopithecus parallel those observed in Ateles. During flexed-elbow vertical climbing, the gait parameters of R. bieti are very similar to those of spider monkeys (Ateles fusciceps) or bonobos (Pan paniscus). Maximum limb joint excursions also lie in the range of hominoids and atelines and are clearly larger than in Macaca fuscata. It seems likely that climbing kinematics may differ more between Rhinopithecus and macaques than between Rhinopithecus and hominoids or atelines.
Evidence of Leopard Predation on Bonobos (Pan paniscus)
Authors: D’Amour Danielle E. , Hohmann Gottfried , Fruth Barbara
Published: April 2006

Current models of social organization assume that predation is one of the major forces that promotes group living in diurnal primates. As large body size renders some protection against predators, gregariousness of great apes and other large primate species is usually related to other parameters. The low frequency of observed cases of nonhuman predation on great apes seems to support this assumption. However, recent efforts to study potential predator species have increasingly accumulated direct and indirect evidence of predation by leopards(Panthera pardus)on chimpanzees and gorillas. The following report provides the first evidence of predation by a leopard on bonobos(Pan paniscus).
Feeding Patterns in a Small-Bodied Nocturnal Folivore (Avahi laniger) and the Influence of Leaf Chemistry: A Preliminary Study
Authors: Faulkner A.L. , Lehman S.M.
Published: April 2006

We present data on feeding patterns in Avahi laniger and compare these data to temporal variations in leaf chemistry. Because A. laniger is one of the smallest folivorous primates and has a monogastric stomach, we hypothesized that this lemur would display behavioural adaptations to a leaf-based diet by scheduling feeding times when leaves were of highest quality. Data were collected from May to August 2004 at the Vatoharanana site in Ranomafana National Park, Madagascar. A. laniger fed during different time periods despite leaf carbohydrate and protein concentrations exhibiting little variation throughout the night. Although tannin concentrations exhibited temporal fluctuations, they did not covary with A. laniger feeding times. We suggest that A. laniger feeding times cannot be explained entirely by variations in leaf chemistry.
The Locomotor Behavior of Callicebus brunneus and Callicebus torquatus
Authors: Lawler Richard R. , Ford Susan M. , Wright Patricia C. , Easley Stephen P.
Published: April 2006

This study presents data on the positional behavior ofCallicebus torquatusandCallicebus brunneuscollected from two different localities in Peru.C. brunneusprimarily utilizes short-distance, bounding leaps, whileC. torquatusrelies predominantly on quadrupedal walking. Both species utilize small, horizontal and terminal branches more than any other substrate class. We relate the differences in locomotor behaviors between the two species to their utilization of different forest levels.C. brunneustends to reside in the understory and brush layer forest levels. These more discontinuous strata necessitate higher frequencies of short-distance leaping.C. torquatusoccupies the more continuous, interconnected canopy level, and much of its food is found in this level. Comparisons with other species show thatCallicebusspp. locomote along smaller-sized, horizontal branches using quadrupedal progression and leaping.
A Universal Microsatellite Multiplex Kit for Genetic Analysis of Great Apes
Authors: Roeder Amy D. , Jeffery Kathryn , Bruford Michael W.
Published: April 2006

DNA profiling with microsatellite markers is a commonly used genetic method of studying the great apes. An efficient method of generating the genetic data is amplification of multiple microsatellites in a single PCR reaction. Here we describe a PCR multiplex in which 9 genetic markers can be amplified simultaneously, thereby saving time, expenses and DNA. This marker system can discriminate between all the great ape species except bonobos and chimpanzees. Furthermore, the cumulative probability of identity values were low for all 4 species tested.
A Dynamic Force Analysis System for Climbing of Large Primates
Authors: Schoonaert Kirsten , D’Août Kristiaan , Aerts Peter
Published: April 2006

Registering substrate reaction forces from primates during climbing requires the design and construction of customized recording devices. The technical difficulties in constructing a reliable apparatus hinder research on the kinetics of primate locomotion. This is unfortunate since arboreal locomotion, especially vertical climbing, is an important component of the hominoid locomotor repertoire. In this technical paper, we describe a custom-built climbing pole that allows recordings of dynamic 3-dimensional forces during locomotion on horizontal and sloping substrates and during vertical climbing. The pole contains an instrumented section that can readily be modified and enables us to register forces of a single limb or multiple limbs in a broad range of primates. For verification, we constructed a similar set-up (which would not be usable for primates) using a conventional force plate. Data for a human subject walking on both set-ups were compared. The experimental set-up records accurate and reliable substrate reaction forces in three orthogonal directions. Because of its adjustability, this type of modular set-up can be used for a great variety of primate studies. When combining such kinetic measurements together with kinematic information, data of great biomechanical value can be generated. These data will hopefully allow biological anthropologists to answer current questions about primate behaviours on vertical substrates.
Reinterpreting Internalization and Agency through G.H. Mead’s Perspectival Realism
Authors: Martin Jack
Published: April 2006

Toward the end of his life, George Herbert Mead developed a theory of perspectives that may be used to reinterpret his social, developmental psychology. This paper attempts such a reinterpretation, leading to the emergence of a theory of perspective taking in early childhood that looks quite different from that which is assumed in most extant work in developmental psychology. Theoretical and empirical implications of Mead’s perspectivism and perspective taking are also explored, with particular focus on questions of internalization and agency. In addition, important distinctions are drawn between Mead’s view of human development and most contemporary theories.
Multiple and Inseparable: Conceptualizing the Development of Independence and Interdependence
Authors: Raeff Catherine
Published: April 2006

Based on the position that cultural ideologies shape child development, many developmental analyses have focused on analyzing cultural conceptions of independence and interdependence. Less attention has been paid to charting the developmental sequences of children’s independent and interdependent behavior that are ostensibly shaped by cultural conceptions of independence and interdependence. Taking a systems view, this paper offers a theoretical framework for conceptualizing independence and interdependence as individual behavioral processes that recognizes the simultaneous separateness and connectedness of all human beings, as well as cultural variability in conceptions of human separateness and connectedness. It is also argued that development involves the increasing differentiation and integration of multiple and inseparable independence and interdependence processes. The theory is illustrated empirically with a consideration of attachment formation during infancy. This approach provides a cohesive framework for guiding developmental analyses of the complexities of children’s independent and interdependent behavior in varied cultures.
Characterization of Osteogenically Induced Adipose Tissue-Derived Precursor Cells in 2-Dimensional and 3-Dimensional Environments
Authors: Leong David Tai , Khor Wei Meng , Chew Fook Tim , Lim Thiam-Chye , Hutmacher Dietmar W.
Published: April 2006

Earlier reports on a putative precursor cell population in adipose tissue showed differentiation along several mesodermal lineages, leading some to think that adipose tissue can be a source of cells applicable in regenerative medicine. However, characterizations of these adipose-derived precursor cells (ADPC) in the 3-dimensional (3-D) environment, especially within the area of bone-specific composite scaffolds, have been lacking. In this study, ADPC plated on culture flasks or seeded on medical grade polycaprolactone-tricalcium phosphate scaffolds (mPCL-CaP) were able to differentiate along the osteogenic lineages in both 2-D and 3-D environments as assessed with immunohistochemistry of osteo-related proteins, reverse transcriptase-polymerase chain reactions and alkaline phosphatase assay. The mPCL-CaP scaffolds provided adipose-derived cells (ADC) with a suitable environment as determined by DNA and metabolic assays, light, confocal and scanning electron microscopy. Flow cytometry revealed ADC to be CD29+, CD44+, CD73+, CD90+ and CD14–, CD31–, CD34–, CD45–, CD71–, and therefore showed the absence of hematopoietic stem cells but possibly the presence of pericytes and mescenchymal stem cells with osteogenic potential. The results of this study demonstrated the potential of using ADPC in combination with mPCL-CaP scaffolds for bone regenerative medicine.
The Neural Tube Is Required to Maintain Primary Segmentation in the Sclerotome
Authors: Colbjørn Larsen Karen , Füchtbauer Ernst-Martin , Brand-Saberi Beate
Published: April 2006

Primary segmentation in vertebrates is considered to be an intrinsic property of the presomitic paraxial mesoderm controlled by a number of interconnected oscillating signals. Resegmentation, in contrast, has been shown to depend on signals from the axial structures. Here we report the requirement of the neural tube for maintenance but not formation of primary segmentation in chick embryos. Unilateral removal of the neural tube, next to the anterior presomitic mesoderm, caused disturbed development of the neural arches and the spinous processes. But already 24 h postsurgery, the sclerotome showed loss of primary segmentation in the craniocaudal axis. Cells strongly expressing twist and not showing any segmentation were located dorsomedially between the remaining left half of the neural tube and the right side dermomyotome, which frequently was truncated medially.
Immunohistochemical Detection of Macrophage Migration Inhibitory Factor in Fetal and Adult Bovine Epididymis: Release by the Apocrine Secretion Mode?
Authors: Eickhoff R. , Jennemann G. , Hoffbauer G. , Schüring M.-P. , Kaltner H. , Sinowatz F. , Gabius H.-J. , Seitz J.
Published: April 2006

Originally defined as a lymphokine inhibiting the random migration of macrophages, the macrophage migration inhibitory factor (MIF) is an important mediator of the host response to infection. Beyond its function as a classical cytokine, MIF is currently portrayed as a multifunctional protein with growth-regulating properties present in organ systems beyond immune cells. In previous studies, we detected substantial amounts of MIF in the rat epididymis and epididymal spermatozoa, where it appears to play a role during post-testicular sperm maturation and the acquisition of fertilization ability. To explore its presence in other species not yet examined in this respect, we extended the range of studies to the bull. Using a polyclonal antibody raised against MIF purified from bovine eye lenses, we detected MIF in the epithelium of the adult bovine epididymis with the basal cells representing a prominently stained cell type. A distinct accumulation of MIF at the apical cell pole of the epithelial cells and in membranous vesicles localized in the lumen of the epididymal duct was obvious. In the fetal bovine epididymis, we also detected MIF in the epithelium, whereas MIF accumulation was evident at the apical cell surface and in apical protrusions. By immunoelectron microscopy of the adult bovine epididymis, we localized MIF in apical protrusions of the epithelial cells and in luminal membrane-bound vesicles that were found in close proximity to sperm cells. Although the precise origin of the MIF-containing vesicles remains to be delineated, our morphological observations support the hypothesis that they become detached from the apical surface of the epididymal epithelial cells. Additionally, an association of MIF with the outer dense fibers of luminal spermatozoa was demonstrated. Data obtained in this study suggest MIF release by an apocrine secretion mode in the bovine epididymis. Furthermore, MIF localized in the basal cells of the epithelium and in the connective tissue could be responsible for regulating the migration of macrophages in order to avoid contact of immune cells with spermatozoa that carry a wide range of potent antigens.
Anatomical Study and Proportional Analysis of the Pig Spleen Arterial Segments
Authors: Pereira-Sampaio Marco Aurélio , Marques-Sampaio Beatriz Pereira de Samuel
Published: April 2006

A systematic study was performed in 31 pig spleens to provide an analysis of the splenic arterial segmentation and an analysis of the proportional area of each segment. There were two independent arterial segments in all cases, a dorsal and a ventral. The dorsal segment was smaller than the ventral segment, presenting 16.81 and 83.19% as the median percentage of the total area of the spleen, respectively. In conclusion, the pig arterial segments are quite similar to those of dog, buffalo, goat, and sheep, where there is a small dorsal segment and a large ventral segment, and somewhat similar to the human spleen, where there are two segments as well, though with a similar area.
Immunocytochemical Characterization of Delta-Opioid and Mu-Opioid Receptor Protein in the Bovine Pineal Gland
Authors: Phansuwan-Pujito Pansiri , Ebadi Manuchair , Govitrapong Piyarat
Published: April 2006

Opioidergic innervation has been identified in the mammalian pineal gland. Recently, opioid receptors in bovine pineal glands have been characterized; the activation of these receptors leads to the stimulation of melatonin synthesis. In this study, the precise localization of opioid receptors in bovine pineal glands was determined by an immunohistochemical technique using antibodies raised against delta-opioid and mu-opioid receptors. Immunoreactivity of these two receptors was present at a moderate level in pinealocytes. A double-labeling study has shown that delta-opioid receptors are localized predominantly with mu-opioid receptors in the same pinealocytes. These immunopositive pinealocytes are often located in a group; however, some of them are dispersed individually. In addition, both types of receptors were found in glial cells and processes. A small number of delta-receptor-immunoreactive nerve fibers were observed in the perivascular space and intraparenchyma of the pineal gland. Mu-opioid receptor immunoreactivity was found in a number of nerve fibers throughout the gland, and in terminal-like dots on pinealocytes. There was immunocolocalization between delta-opioid receptors or mu-opioid receptors and leu-enkephalin in some nerve fibers. The results of this study indicate that the modulatory effect of the opioid system on melatonin secretion in pineal glands might act via opioid receptors on pinealocytes, whereas receptors located on nerve fibers might modulate the release of opioid peptides.
Differential Densities of Muscarinic Acetylcholine Receptor and IK,ACh in Canine Supraventricular Tissues and the Effect of Amiodarone on Cholinergic Atrial Fibrillation and IK,ACh
Authors: Huang Cong-Xin , Zhao Qing-Yan , Liang Jin-Jun , Chen Hui , Yang Bo , Jiang Hong , Li Geng-Shan
Published: April 2006

Background: Vagal nerve plays an important role in the induction and maintenance of atrial fibrillation (AF). This study investigated the differential densities of M2 receptor and acetylcholine-induced inward rectifier K+ current (IK,ACh) in atrial appendage, atrium, pulmonary vein (PV) and super vena cava (SVC) to discuss the role of atrial appendage and PV in cholinergic AF. Methods and Results: In 10 dogs, action potential duration was determined at 24 sites during bilateral cervical vagal stimulation and amiodarone administration. AF could be induced at first in right atrial appendage (RAA) and right atrium (RA) without left atrial appendage (LAA) and left atrium (LA). Amiodarone decreased the initiation of AF in vivo. Western blot and patch clamp were used to determine M2 receptor and IK,ACh in RAA, LAA, RA, LA, PV and SVC. The densities of M2 receptor and IK,ACh in LAA, RAA and LA were higher than that in RA, PV and SVC (21.34 ± 0.92 vs. 8.24 ± 0.45 pA/pF, p < 0.05). Furthermore, the densities of the M2 receptor and IK,ACh in LAA and RAA were higher than that in LA (21.34 ± 0.92 vs. 14.17 ± 0.65 pA/pF, p < 0.05). After amiodarone administration, densities of IK,ACh in LA and RA were not different, but densities of IK,ACh were also less in atrium than in atrial appendage. Conclusions: Densities of the M2 receptor and IK,ACh are higher in atrial appendage than other sites. Atrial appendage perhaps plays an important role in initiation of cholinergic AF. However, PV and SVC less often play an important role in vagotonic paroxysmal AF. Reduced dispersion of IK,ACh is the mechanism for amiodarone to therapy AF.
Effect of Hormone Replacement Therapy on Plasma Lipoproteins and Apolipoproteins, Endothelial Function and Myocardial Perfusion in Postmenopausal Women with Estrogen Receptor-α IVS1–397 C/C Genotype and Established Coronary Artery Disease
Authors: Emre Ayse , Sahin Sinan , Erzik Can , Nurkalem Zekeriya , Oz Dilaver , Cırakoglu Beyazit , Yesilcimen Kemal , Ersek Birsen
Published: April 2006

Effect of hormone replacement (HRT) therapy on plasma lipoproteins and apolipoproteins, endothelial function and myocardial perfusion in postmenopausal women with estrogen receptor-α (ER-α) IVS1–397 C/C genotype and established coronary artery disease. Background/Aims: Associations between various ER-α polymorphisms and clinical phenotypes have been studied, including lipid levels and coronary atherosclerosis. We studied 48 postmenopausal women to determine the effect of ER-α IVS1–397 polymorphism on the response to treatment with HRT. Methods: The study had a randomized, double-blind, placebo-controlled and crossover design. Patients were divided into two groups according to ER-α IVS1–397 polymorphism: CC genotype (n = 9); CT or TT genotype (n = 39). HRT was given continuously for 4 weeks, with 4-week washout periods between the treatment periods. Brachial artery Doppler and Tl-201 scintigraphy were performed at the end of each treatment period. Results: HRT lowered total cholesterol, LDL-c and Apo-B levels from baseline values (all p < 0.05) and to a similar degree in CC and CT/TT genotype patients. HRT increased estradiol, HDL-c and Apo A-1 levels relative to baseline values, but to a greater degree in CC patients (p = 0.04, 0.05 and 0.04 by ANOVA, respectively). HRT increased peak forearm blood flow, brachial artery diameter during reactive hyperemia and endothelium-dependent dilation in both groups, but to a greater degree in CC patients (p = 0.03, 0.03 and 0.04 by ANOVA, respectively). Summed stress and rest scores were also more markedly reduced in CC patients (p = 0.04 and 0.05, respectively). The increase in estradiol levels was strongly correlated with the improvement in endothelium-dependent dilation (r = 0.66, p < 0.01), which in turn showed negative correlation with summed stress (r = –0.62, p < 0.01) and rest scores (r = –0.52, p < 0.05) in the CC genotype group. Conclusion: These data suggest that the improvement in endothelium-dependent dilation and the reduction in perfusion abnormalities by increasing estradiol levels with HRT in postmenopausal women with coronary artery disease may differ with respect to different genotypes, the effect being more prominent in those patients with ER-α IVS1–397 CC genotype.
Coronary Artery Bypass Grafting Is Associated with a Significant Worsening of QT Dynamicity and Heart Rate Variability
Authors: Yavuz Bunyamin , Duman Umit , Abali Gulcan , Dogan Omer Faruk , Yazicioglu Alkin , Sahiner Levent , Aytemir Kudret , Tokgozoglu Lale , Demircin Metin , Nazli Nasih , Kabakci Giray , Oto Ali
Published: April 2006

Background: Imbalance in autonomic nervous system and impaired myocardial repolarization has been shown to increase the risk for arrhythmias in patients with coronary artery disease. This study evaluated the effects of coronary artery bypass grafting (CABG) on heart rate variability and QT interval dynamicity in subjects with coronary artery disease undergoing elective CABG surgery. Methods: The study group consisted of 68 consecutive patients (mean age ±SD: 61 ± 9 years) with coronary artery disease who underwent elective CABG. Twenty-four-hour Holter monitoring was performed 2–5 days before cardiac surgery and was repeated 10 days after CABG. ELATEC holter software was used to calculate heart rate variability and QT dynamicity parameters. All subjects had a complete history, laboratory examination and transthoracic echocardiography. Results: All patients had beta-blocking agent medication pre- and postoperatively. Standard deviation of all NN intervals for a selected time period, square root of the mean of the sum of the squares of differences between adjacent RR intervals, the proportion of differences in successive NN intervals greater than 50 ms, normalized low-frequency power, and normalized high-frequency power were significantly decreased after CABG surgery, whereas low-frequency/high-frequency ratio was significantly increased after CABG. QT/RR slopes over 24 h were significantly increased after CABG surgery for QT end and QT apex (QTapex/RR: 0.16 ± 0.13 vs. 0.28 ± 0.19, p < 0.001; QTend/RR: 0.18 ± 0.13 vs. 0.36 ± 0.23, p < 0.001). Conclusion: This prospective study showed for the first time that CABG was associated with a significant worsening of heart rate variability and QT dynamicity parameters in the postoperative period.
Dilated Cardiomyopathy: An Unusual Presentation of Aortic Coarctation in an Infant
Authors: Hwang Mao-Sheng , Chu Jaw-Ji , Chang Yu-Sheng , Su Wen-Jen
Published: April 2006

Coarctation of the aorta commonly presents in infancy as congestive heart failure, or later in childhood as hypertension or as a heart murmur. However, we experienced a unique infant case of isolated coarctation presenting with acute decompensation of a dilated cardiomyopathy, which recovered completely 8 months postoperatively. Our report highlights the previously unreported presentation of coarctation in infancy as a dilated cardiomyopathy. It also implies that before we label any patient presenting with a dilated cardiomyopathy as an idiopathic cardiomyopathy, we must exclude all possible specific causes of myocardial dysfunction because many such specific cardiomyopathies are curable and very rewarding, just like our patient.
Congenital Left Ventricular Aneurysms and Diverticula: Definition, Pathophysiology, Clinical Relevance and Treatment
Authors: Ohlow Marc-Alexander
Published: April 2006

A congenital left ventricular aneurysm or diverticulum is a rare cardiac malformation; 411 cases have been reported since its first description in 1816, and other cardiac, vascular or thoraco-abdominal abnormalities have been shown in about 70%. It appears to be a developmental anomaly, starting in the 4th embryonic week. Diagnosis can be made after exclusion of coronary artery disease, local or systemic inflammation or traumatic causes as well as cardiomyopathies. Clinically, most congenital left ventricular aneurysms and diverticula are asymptomatic or may cause systemic embolization, heart failure, valvular regurgitation, ventricular wall rupture, ventricular tachycardia or sudden cardiac death. Diagnosis is established by imaging studies such as echocardiography, magnetic resonance imaging or left ventricular angiography, visualizing the structural changes and accompanying abnormalities. Mode of treatment has to be individually tailored and depends on clinical presentation, accompanying abnormalities and possible complications; treatment options include surgical resection especially in symptomatic patients, anticoagulation after systemic embolization, radiofrequency ablation or implantation of an implantable cardioverter defibrillator in case of symptomatic ventricular tachycardia, occasionally combined with class I or III antiarrhythmic drugs.
Aneurysms of the Sinuses of Valsalva
Authors: Feldman Dmitriy N. , Roman Mary J.
Published: April 2006

Sinus of Valsalva aneurysms are rare cardiac anomalies which may be acquired or congenital, most commonly involving the right or noncoronary sinuses. The congenital aneurysms are more common and often caused by weakness at the junction of the aortic media and the annulus fibrosus. Acquired aneurysms are caused by conditions affecting the aortic wall, such as infections (syphilis, bacterial endocarditis, or tuberculosis), trauma, or connective tissue disorders. Unruptured aneurysms are usually found incidentally during diagnostic studies. More commonly, sinus of Valsalvaaneurysms are diagnosed after clinical sequelae of rupture. Diagnosis of sinus of Valsalva aneurysm is facilitated by echocardiography, contrast aortography, and more recently, magnetic resonance imaging. Repair is generally required for ruptured aneurysms; unruptured aneurysms encroaching on nearby structures, causing myocardial ischemia, or having the potential to rupture warrant repair. A review of the literature is presented focusing on anatomy, clinical presentation of ruptured and unruptured aneurysms, noninvasive diagnostic modalities, and techniques for repair of this anomaly.
Effects of Fluid Shear Stress on eNOS mRNA Expression and NO Production in Human Endothelial Progenitor Cells
Authors: Tao Jun , Yang Zhen , Wang Jie-Mei , Tu Chang , Pan Shi-Rong
Published: April 2006

The increases in physiological levels of fluid shear stress have beneficial effects on vascular homeostasis. Endothelial progenitor cells (EPCs) play an important role in the maintenance of endothelial integrity. We hypothesized that shear stress-mediated vascular protection is related to the upregulation of endothelial nitric oxide synthase expression in EPCs. The human EPCs exposed to in vitro shear stress levels of 5, 15 and 25 dyn/cm2 for 4 h. In vitro shear stress, in a dose-dependent fashion, increased the endothelial nitric oxide synthase mRNA expression and the nitric oxide production in human EPCs. The present findings for the first time provide novel insights into the mechanisms of the physiological levels of fluid shear stress on the regulation of human EPC biologic phenotype as a potential factor, which might contribute to vascular protective activities in humans although evidence is indirect.