Lysophosphatidylcholine derived from deer antler extract suppresses hyphal transition in Candida albicans through MAP kinase pathway. (9/92)

A family of 2-lysophosphatidylcholines (lyso-PCs) was isolated from deer antler extract, guided exclusively by hyphal transition inhibitory activity in Candida albicans. Structural determination of the isolated lyso-PCs by spectroscopic methods, including infrared spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR, 2D correlation spectroscopy NMR, fast atom bombardment mass spectrometry and tandem mass spectrometry, confirmed that the natural products were composed of at least four different lyso-PCs varying in fatty acid moiety at the sn-1 position of the glycerol backbone. The major lyso-PCs were confirmed as 1-stearoyl-, 1-oleoyl-, 1-linoleoyl- and 1-palmitoyl-2-lyso-sn-glycero-3-phosphatidylcholines. Lyso-PC specifically suppressed the morphogenic transition from yeast to hyphae in C. albicans, without affecting the growth of either yeast or hyphae. Lyso-PC exerted hyphal transition that suppressed activity in the broad spectrum of the Candida species, such as C. albicans, Candida krusei, Candida guilliermondii and Candida parapsilosis. Northern analysis indicated that the suppression was mediated through the mitogen-activated protein kinase pathway.  (+info)

Does fluctuating asymmetry of antlers in white-tailed deer (Odocoileus virginianus) follow patterns predicted for sexually selected traits? (10/92)

Secondary sexual characters have been hypothesized to signal male quality and should demonstrate a negative relationship between the size of the trait and degree of fluctuating asymmetry because they are costly to produce. We collected morphometric and antler data from 439 white-tailed deer (Odocoileus virginianus) in Oklahoma, USA, in order to determine whether measures of antler asymmetry follow the patterns predicted for sexually selected characters. Relative fluctuating asymmetry was negatively related to antler size for all deer and within age groups up to five and a half years of age. We did not detect an association between asymmetry and antler size among deer that were six and a half years or older. When categorizing deer by antler size, we found that deer with small antlers (< or = 33rd percentile) had greater levels of relative asymmetry than deer with large antlers (< or = 67th percentile). The relative asymmetry of antlers was negatively related to age and was greatest in deer that were one and a half years old. Relative asymmetry was also negatively related to carcass mass, inside spread, skull length and body length. These data suggest that asymmetry in the antlers of white-tailed deer may be a reliable signal of quality and, as such, may be important in maintaining honesty in intrasexual advertisements during the breeding season.  (+info)

Comparison of analgesic techniques for antler removal in wapiti. (11/92)

The purpose of this research was to compare the effectiveness of ring block anesthesia (LA) and electroanesthesia (A) for antler removal in elk given a long-acting tranquilizer to remove stress from restraint. Thirty-two male wapiti were given 1 mg/kg body weight of zuclopenthixol acetate; the next day, they were restrained in a hydraulic chute, provided with electroanesthesia or a lidocaine ring block, and had their antlers removed. Behavioral response to antler removal was scored. Significantly more (P = 0.032) animals responded to antler removal in the EA group. Heart rates and arterial pressures were measured by a catheter connected to a physiological monitor. Heart rate increased significantly over time with EA, but not with LA. Heart rate increased from baseline significantly more in the EA group immediately prior to antler removal (P = 0.017), immediately post antler removal (P = 0.001), and at 1 min post antler removal (P = 0.037). It was concluded that EA is not as effective a method of anesthesia as is LA for antler removal.  (+info)

Effect of zeranol or melengestrol acetate (MGA) on testicular and antler development and aggression in farmed fallow bucks. (12/92)

Fifteen yearling fallow bucks were randomly assigned by BW to one of three treatment groups: control (C; n = 5), melengestrol acetate (MGA; n = 5), and zeranol (Z; n = 5), to evaluate effects on testicular development, aggressive behavior, antler growth, sexual activity, ADG, and BW. Zeranol-treated bucks received zeranol ear implants (36 mg) at 90-d intervals, and MGA-treated bucks received MGA in the ration (100 microg x animal(-1) x d(-1)). Bucks grazed ryegrass/Coastal bermudagrass pasture and were supplemented with 3:1 corn/soybean meal at 0.45 kg x animal(-1) x d(-1). Body weights, body condition scores (BCS), blood samples, and testis measurements were obtained at d 0 and at 14-d intervals for 229 d. As bucks reached hard antler (7/15 to 8/25), antlers were harvested and weighed, and ejaculates were collected at 14-d intervals. Aggression was evaluated using 10-min video sessions scoring body blows, avoidance, head pushes, and head bunts. Scrotal circumference (SC) and paired testis volume were affected by a day x treatment interaction (P < 0.01); testes of zeranol-treated bucks were smaller than those of control or MGA-treated bucks. First sperm in the ejaculate tended to be delayed (P < 0.10) in zeranol-treated bucks compared with control and MGA-treated bucks. Melengestrol acetate-treated bucks had a maximum sperm concentration in the ejaculate that was three times (P < 0.05) that of control bucks and nine times (P < 0.05) that of zeranol-treated bucks. Antler weight was the least (P < 0.01) for bucks receiving zeranol and greatest (P < 0.10) for MGA-treated bucks; intermediate values were recorded for the control bucks. Aggressive behavior was delayed (P < 0.05) for zeranol-treated bucks until treatment effects were overcome. Melengestrol acetate-treated bucks had decreased (P < 0.01) aggressive behavior compared with control bucks. Melengestrol acetate-treated bucks had increased (P < 0.05) serum testosterone concentrations compared with control and zeranol-treated bucks. Human chorionic gonadotropin-stimulated peak serum testosterone concentrations for zeranol-treated bucks were delayed (P < 0.01) compared with control and MGA-treated bucks. Although zeranol-treated bucks overcame treatment effects, they were never able to reach testicular measurements or sperm concentrations equal to those of the control or MGA-treated bucks. Zeranol and MGA treatments may have both positive and negative effects that can be utilized when producing slaughter bucks.  (+info)

Histochemical and ultrastructural studies of cartilage resorption and acid phosphatase activity during antler growth in fallow deer (Dama dama). (13/92)

Cartilage resorption in forming primary fallow deer antlers was studied by histochemistry and electron microscopy. A high activity of tartrate-resistant acid phosphatase (TRAP), a histochemical marker of skeletal resorbing cells, was first detected in cells located in the mesenchymal tissue separating the columns of hypertrophic cartilage. No cartilage resorption was observed in this region. Intense TRAP staining occurred in large multinucleated cells (identified as inactive osteoclasts) as well as in smaller cells (regarded as mononuclear osteoclast progenitors). On the basis of these findings it was concluded that this was the region where osteoclasts differentiated from progenitor cells. Further proximally, the mineralized cartilage was eroded by active osteoclasts that were located in Howship's lacunae and exhibited an intense TRAP staining. Electron microscopy showed that the cells identified as inactive osteoclasts lacked a polarized organization. In contrast, the active osteoclasts in the zone of cartilage resorption exhibited a typical polarized organization: the nuclei congregated near the basolateral cell surface, and there was a zone of deep membrane infoldings (ruffled border) surrounded by a clear zone at the apical cell pole adjacent to the resorption surface of the mineralized cartilage. The multinucleated cartilage-resorbing cells of the forming antler thus exhibited the typical histochemical and morphological features of active mammalian osteoclasts. Low levels of TRAP activity were also observed in hypertrophic chondrocytes; however, the specificity and potential significance of this staining remain to be elucidated.  (+info)

Sampling technique to discriminate the different tissue layers of growing antler tips for gene discovery. (14/92)

The utilization of a deer antler model to study gene expression in tissues undergoing rapid growth has been hampered by an inability to sample the different tissue types. We report here a standardized procedure to identify different tissue types in growing antler tips and demonstrate that it can help in the classification of expressed sequence tags (ESTs). The procedure was developed using observable morphological markers within the unstained tissue at collection, and was validated by histological assessments and virtual Northern blotting. Four red deer antlers were collected at 60 days of growth and the tips (top 5 cm) were then removed. The following observable markers were identified distoproximally: the dermis (4.86 mm), the subdermal bulge (2.90 mm), the discrete columns (6.50 mm), the transition zone (a mixture of discrete and continuous columns) (3.22 mm), and the continuous columns (8.00 mm). The histological examination showed that these markers corresponded to the dermis, reserve mesenchyme, precartilage, transitional tissue from precartilage to cartilage, and cartilage, respectively. The gene expression studies revealed that these morphologically identified layers were functionally distinct tissue types and had distinct gene expression profiles. We believe that precisely defining these tissue types in growing antler tips will greatly facilitate new discoveries in this exciting field.  (+info)

A role for retinoic acid in regulating the regeneration of deer antlers. (15/92)

Deer antlers are the only mammalian organs that can be repeatedly regenerated; each year, these complex structures are shed and then regrow to be used for display and fighting. To date, the molecular mechanisms controlling antler regeneration are not well understood. Vitamin A and its derivatives, retinoic acids, play important roles in embryonic skeletal development. Here, we provide several lines of evidence consistent with retinoids playing a functional role in controlling cellular differentiation during bone formation in the regenerating antler. Three receptors (alpha, beta, gamma) for both the retinoic acid receptor (RAR) and retinoid X receptor (RXR) families show distinct patterns of expression in the growing antler tip, the site of endochondral ossification. RAR alpha and RXR beta are expressed in skin ("velvet") and the underlying perichondrium. In cartilage, which is vascularised, RXR beta is specifically expressed in chondrocytes, which express type II collagen, and RAR alpha in perivascular cells, which also express type I collagen, a marker of the osteoblast phenotype. High-performance liquid chromatography analysis shows significant amounts of Vitamin A (retinol) in antler tissues at all stages of differentiation. The metabolites all-trans-RA and 4-oxo-RA are found in skin, perichondrium, cartilage, bone, and periosteum. The RXR ligand, 9-cis-RA, is found in perichondrium, mineralised cartilage, and bone. To further define sites of RA synthesis in antler, we immunolocalised retinaldehyde dehydrogenase type 2 (RALDH-2), a major retinoic acid-generating enzyme. RALDH-2 is expressed in the skin and perichondrium and in perivascular cells in cartilage, although chondroprogenitors and chondrocytes express very low levels. At sites of bone formation, differentiated osteoblasts which express the bone-specific protein osteocalcin express high levels of RALDH2. The effect of RA on antler cell differentiation was studied in vitro; all-trans-RA inhibits expression of the chondrocyte phenotype, an effect that is blocked by addition of the RAR antagonist Ro41-5253. In monolayer cultures of mesenchymal progenitor cells, all-trans-RA increases the expression of alkaline phosphatase, a marker of the osteoblastic phenotype. In summary, this study has shown that antler tissues contain endogenous retinoids, including 9-cis RA, and the enzyme RALDH2 that generates RA. Sites of RA synthesis in antler correspond closely with the localisation of cells which express receptors for these ligands and which respond to the effects of RA.  (+info)

Comparison of lidocaine and compression for velvet antler analgesia in wapiti. (16/92)

This research compared ring block lidocaine anesthesia (L) and compression (C) for velvet antler removal in elk. Thirty-two wapiti were given 1 mg/kg body weight of zuclopenthixol acetate. The next day, they were restrained in a hydraulic chute and given either a compression device or a lidocaine ring block on the antler pedicle. Behavioral and physiological responses to treatment application and antler removal were recorded, and blood was collected for cortisol analysis. During application of L and C, increases in mean heart rate and systolic arterial blood pressure were greater in the C treatment group (P < 0.05, and P = 0.05, respectively). When antler was removed, more behavioral responses occurred in the C treatment group (P = 0.02) and its median behavior score was higher (P = 0.03). Mean heart rates increased for both treatment groups when antlers were removed (P < 0.01). It was concluded that application of C may be painful, and that C was not as effective as L for analgesia for velvet antler removal.  (+info)