Interplay between plasma hormone profiles, sex and body condition in immature hawksbill turtles (Eretmochelys imbricata) subjected to a capture stress protocol

We investigated plasma hormone profiles of corticosterone and testosterone in immature hawksbill turtles (Eretmochelys imbricata) in response to a capture stress protocol. Further, we examined whether sex and body condition were covariates associated with variation in the adrenocortical response of immature turtles. Hawksbill turtles responded to the capture stress protocol by significantly increasing plasma levels of corticosterone over a 5 h period. There was no significant sex difference in the corticosterone stress response of immature turtles. Plasma testosterone profiles, while significantly different between the sexes, did not exhibit a significant change during the 5 h capture stress protocol. An index of body condition was not significantly associated with a turtle's capacity to produce plasma corticosterone both prior to and during exposure to the capture stress protocol. In summary, while immature hawksbill turtles exhibited an adrenocortical response to a capture stress protocol, neither their sex nor body condition was responsible for variation in endocrine responses. This lack of interaction between the adrenocortical response and these internal factors suggests that the inactive reproductive- and the current energetic- status of these immature turtles are important factors, that could influence plasma hormone profiles during stress. (C) 2003 Elsevier Inc. All rights reserved.

Chic chicks: the evolution of chick ornamentation in rails

Competition over access to food has led to the evolution of a variety of exaggerated visual and vocal displays in altricial nestling birds. Precocial chicks that are fed by their parents also vary widely in appearance ranging from those with inconspicuous coloration to those with brightly colored bills, fleshy parts, and plumes. These ornaments are lost by the end of the period of parental dependence, suggesting they function in competition over parental care. We use a comparative approach to evaluate which ecological or life-history variables may have favored the evolution of conspicuous ornamentation in precocial chicks. We compiled data on chick morphology, ecology, and social organization of species in the Family Rallidae, a group with highly variable downy chicks. Chick ornamentation in the form of brightly colored bills, fleshy patches, or plumes is observed in 36 of 97 species for which downy chicks are described. Phylogenetic reconstructions suggest that nonornamentation is the ancestral state. Chick ornamentation has evolved multiple times within the Rallidae and is significantly associated with large clutch sizes and polygamous mating systems. Chick ornamentation was also weakly associated with adult ornamentation and adult dimorphism. We argue that these results support the hypothesis that lineages with higher levels of sibling competition are more likely to evolve ornamented chicks.

Diffusion modeling of percutaneous absorption kinetics: 3. Variable diffusion and partition coefficients, consequences for stratum corneum depth profiles and desorption kinetics

Stratum corneum (SC) desorption experiments have yielded higher calculated steady-state fluxes than those obtained by epidermal penetration studies. A possible explanation of this result is a variable diffusion or partition coefficient across the SC. We therefore developed the diffusion model for percutaneous penetration and desorption to study the effects of either a variable diffusion coefficient or variable partition coefficient in the SC over the diffusion path length. Steady-state flux, lag time, and mean desorption time were obtained from Laplace domain solutions. Numerical inversion of the Laplace domain solutions was used for simulations of solute concentration-distance and amount penetrated (desorbed)-time profiles. Diffusion and partition coefficients heterogeneity were examined using six different models. The effect of heterogeneity on predicted flux from desorption studies was compared with that obtained in permeation studies. Partition coefficient heterogeneity had a more profound effect on predicted fluxes than diffusion coefficient heterogeneity. Concentration-distance profiles show even larger dependence on heterogeneity, which is consistent with experimental tape-stripping data reported for clobetasol propionate and other solutes. The clobetasol propionate tape-stripping data were most consistent with the partition coefficient decreasing exponentially for half the SC and then becoming a constant for the remaining SC. (C) 2004 Wiley-Liss, Inc.

Changes in body water distribution during treatment with inhaled steroid in pre-school children

Primary objective: The study aimed to examine the changes in water distribution in the soft tissue during systemic steroid activity. Research design: A three-way cross-over, randomized, placebo-controlled, double-blind trial was used, including 4 weeks of fluticasone propionate pMDI 200 mug b.i.d. delivered via Babyhaler(R), budesonide pressurized metered dose inhaler (pMDI) 200 mug b.i.d. delivered via Nebuchamber(R) and placebo. Spacers were primed before use. In total, 40 children aged 1-3 years, with mild intermittent asthma were included. Twenty-five of the children completed all three treatments. At the end of each treatment period body impedance and skin ultrasonography were measured. Methods and procedures: We measured changes in water content of the soft tissues by two methods. Skin ultrasonography was used to detect small changes in dermal water content, and bioelectrical impedance was used to assess body water content and distribution. Main outcomes and results: We found an increase in skin density of the shin from fluticasone as measured by ultrasonography (p = 0.01). There was a tendency for a consistent elevation of impedance parameters from active treatments compared to placebo although overall this effect was not statistically significant (0.1< p <0.2). However, sub-analyses indicated a significant effect on whole-body and leg impedance from budesonide treatment (p <0.05). Conclusion: Decreased growth during inhaled steroid treatment seems to partly reflect generalized changes in body water.

Short-term effects of carbon source on the competition of polyphosphate accumulating organisms and glycogen accumulating organisms

The effectiveness of enhanced biological phosphorus removal (ESPR) systems is directly affected by the competition of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs). This study investigated the short-term effects of carbon source on PAO and GAO performance. The tests were designed to clearly determine the impact of volatile fatty acid (VFA) composition on the performance of two types of biomass, one enriched for PAOs and the other for GAOs. The two populations were enriched in separate reactors using identical operating conditions and very similar influent compositions with acetate as the sole carbon source. The only difference was that a very tow level of phosphorus was present in the influent to the GAO reactor. The abundance of PAOs and GAOs was quantified using fluorescence in-situ hybridisation. The results clearly show that there are some very distinctive differences between PAOs and GAOs in their ability to utilise different carbon substrates. While both are able to take up acetate rapidly and completely, the GAOs are far slower at consuming propionate than the PAOs during short-term substrate changes. This provides a potentially highly valuable avenue to influence the competition between PAOs and GAOs. Other VFAs studied seem to be less usable in the short term by both PAOs and GAOs; as indicated by their much lower uptake rates.

Conjugation of an antibody to cross-linked fibrin for targeted delivery of anti-restenotic drugs

There is an urgent need to treat restenosis, a major complication of the treatment of arteries blocked by atherosclerotic plaque, using local delivery techniques. We observed that cross-linked fibrin (XLF) is deposited at the site of surgical injury of arteries. An antibody to XLF, conjugated to anti-restenotic agents, should deliver the drugs directly and only to the site of injury. An anti-XLF antibody (H93.7C.1D2/48; 1D2) was conjugated to heparin (using N-succinimidyl 3-(2-pyridyldithio)-propionate), low molecular weight heparin (LMWH) (adipic acid dihydrazide) and rapamycin (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide), and the conjugates purified and tested for activity before use in vivo. Rabbits had their right carotid arteries de-endothelialised and then given a bolus of 1D2-heparin, 1D2-LMWH or 1D2-rapamycin conjugate or controls of saline, heparin, LMWH, rapamycin or 1D2 (+/-heparin bolus) and sacrificed after 2 or 4 weeks (12 groups, n=6/group). Rabbits given any of the conjugates had minimal neointimal development in injured arteries, with up to 59% fewer neointimal cells than those given control drugs. Rabbits given 1D2-heparin or 1D2-LMWH had an increased or insignificant reduction in luminal area, with positive remodelling, while the medial and total arterial areas of rabbits given 1D2-rapamycin were not affected by injury. Arteries exposed to 1D2-heparin or 1D2-rapamycin had more endothelial cells than rabbits given control drugs. Thus, XLF-antibodies can site-deliver anti-restenotic agents to injured areas of the artery wall, where the conjugates can influence remodelling, re-endothelialisation and neointimal cell density, with reduced neointimal formation. (C) 2004 Elsevier B.V. All rights reserved.

Carpal glands in feral pigs (Sus domesticus) in tropical lowland rainforest in north-east Queensland, Australia

Carpal glands (CG) of 105 feral pigs Sus domesticus, caught in the tropical lowland rainforest in northeast Queensland, Australia, between 1999 and 2004, were investigated to examine their function in chemical communication between animals, and their histology. Female feral pigs show significantly larger CG on the right leg than on the left leg while there were no side-specific differences in males. CG on both legs were significantly larger in reproductive than in non-reproductive females, but they did not differ between pregnant and lactating females. The results suggest that CG are involved in the defensive behaviour of reproductive females but not in the identification of the mother by piglets. The area of the left CG was significantly bigger in males compared to females, but no significant difference could be shown for the CG on the right legs. CG of same-aged boars did not change significantly in size throughout the year while females showed smaller CG on the left leg in January and February suggesting that CG may be involved in intra-matriarchal group communication, Same sized and aged boars did not show any correlations between the size of the CG and the weight of their testes and the serum levels of testosterone. These results suggest that CG are not involved in advertising dominance in boars. The histological investigation of CG showed that they are active in feral pigs in the lowland rainforest, consist mainly of apocrine tissue and that their hairs may play a role in distributing secretion.

Monensin supplementation of lactating cows fed tropical grasses and cane molasses or grain

Effects of monensin (Mon) on performance of Holstein-Friesian cows fed tropical grasses and cane molasses (M) or cereal grain were examined in three experiments. In experiment I (incomplete 4 x 4 Latin square), three rumen-fistulated cows [188 I I days in milk (DIM)] were fed mixed diets based on rhodes grass (Chloris gayana cv. Callide) bay where M was substituted for wheat grain (W) at rates of 0 (MO), 125 (M 125) or 250 (M250) g/kg dry matter (DM). A fourth diet contained M250 plus 0.02 g Mon/kg DM (M250 + Mon). Substituting M for W tended (P < 0.10) to decrease the ratio of rumen molar proportions of acetate+butyrate (Bu):propionate (Pr) (4.3 versus 3.8 and 4.0 for M0, M125 and M250, respectively). There were no treatment effects (P> 0.10) on intake, organic matter digestibility, milk production or liveweight (LW) change. In experiment 2, 48 cows (173 &PLUSMN; 28.3 DIM) grazing kikuyu (Pennisetum clandestinum cv. common) pastures and supplemented with maize silage and a grain-based concentrate were offered either M (2.6 kg DM/(cow day)) or barley grain (B) (2.7 kg DM/(cow day)). Within each supplement type, half were fed 0 or 320 mg of Mon/(cow day). There were Mon x supplement interactions (Mon x S; P < 0.05) on the rumen molar proportion of Pr and Bu at 15:00 h, with B + Mon having the highest value for Pr (0.259 mmol/mmol) and lowest value for Bu (0.121 mmol/mmol). A Mon x S effect (P < 0.05) on milk fat content was noted with Mon causing a lower value regardless of energy source (31 and 36 g/l versus 40 and 38 g/l for B + Mon, M + Mon, B - Mon and M - Mon, respectively). As a main effect, M as opposed to B, reduced yields of milk (P < 0.05; 16.21/(cow day) versus 18.01/(cow day)) and protein (P < 0.05; 479 g/(cow day) versus 538 g/(cow day)). Monensin reduced milk fat yield (P < 0.05; 669 g/(cow day) versus 562 g/(cow day)), raised milk protein concentration (P < 0.05; 31 g/l versus 29 g/l) and caused LW gain rather than loss (P < 0.05; +0.06 kg/(cow day) versus -0.30 kg/(cow day)). No treatment effects on pasture intake were noted. In experiment 3, 48 cows (91 &PLUSMN; 16.1 DIM) grazing kikuyu pasture and supplemented with grain-based concentrate, sugar cane silage and 2.7 kg DM(cow day) of M were supplemented with either 0 or 320 mg Mon/(cow day). Monensin reduced (P < 0.05) milk fat content (33 g/l versus 30 g/l) and tended (P < 0.10) to reduce milk protein content (29 g/l versus 28 g/l). No effects of Mon on other milk production parameters, LW change or pasture intake were noted. Feeding monensin to mid-lactation Holstein-Friesian cows offered diets based on tropical grasses, and cane molasses or grain, improves rumen fermentation efficiency, thereby improving energy efficiency resulting in higher LW gain. Monensin had no effect on milk yield, but reduced milk fat concentration.

Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam

Introduced species are an increasingly pervasive problem. While studies on the ecology and behavior of these pests are numerous, there is relatively little known of their physiology, specifically their reproductive and stress physiology. One of the best documented introduced pest species is the brown tree snake, Boiga irregularis, which was introduced onto the Pacific island of Guam sometime around World War II. The snake is responsible for severely reducing Guam's native vertebrates. We captured free-living individuals throughout the year and measured plasma levels of stress and sex hormones in an effort to determine when they were breeding. These data were compared to reproductive cycles from a captive population originally collected from Guam. Free-living individuals had chronically elevated plasma levels of the stress hormone corticosterone and basal levels of sex steroids and a remarkably low proportion were reproductively active. These data coincide with evidence that the wild population may be in decline. Captive snakes, had low plasma levels of corticosterone with males displaying a peak in plasma testosterone levels during breeding. Furthermore, we compared body condition between the free-living and captive snakes from Guam and free-living individuals captured from their native range in Australia. Male and female free-living snakes from Guam exhibited significantly reduced body condition compared to free-living individuals from Australia. We suggest that during the study period, free-living brown tree snakes on Guam were living under stressful conditions, possibly due to overcrowding and overexploitation. of food resources, resulting in decreased body condition and suppressed reproduction. (C) 2004 Elsevier Ltd. All rights reserved.

Doubling daily inhaled corticosteroid dose is ineffective in mild to moderately severe attacks of asthma in adults

Background: Asthma guidelines recommend increasing or doubling inhaled corticosteroid (ICS) dose to treat mild and moderate exacerbations of asthma in adults. Aim: To: (i) compare the effectiveness of doubling existing daily ICS dose (fluticasone) with maintaining usual ICS dose and usual daily ICS dose accompanied by oral steroids (OS) (dexamethasone) during mild and moderately severe exacerbations of asthma in adults; (ii) examine determinants of success and failure; and (iii) compare side-effect profiles. Methods: A randomized, double-blind, placebo-controlled (double-dummy), triple crossover trial. Participants acted as their own control. Outcome measures included treatment success/failure, peak expiratory flow (PEF) after 7 days therapy or at treatment failure, and side-effects. Results: From 22 participants (nine males and 13 females), 18 pairs of data were available for maintaining usual ICS versus doubling ICS and doubling ICS versus OS, and 19 for maintaining usual ICS versus OS. Median (fifth-95th percentile) age was 46.5 (32-64) years and forced expiratory volume in one second (FEV1) 73% (29-97%) predicted. The outcome after doubling ICS was not superior to maintaining usual ICS, with 11 (61%) failures in both arms (P = 0.66). OS, with only 5 (26%) failures, was superior to maintaining usual ICS with 12 (63%) failures (P = 0.04), and to doubling ICS with 5 (28%) versus 11 (61%) failures (P = 0.07). Median PEF (as percentage of run-in best) at end-points were 90.5% (57.1-177.1) for OS, 78.3% (39.5-103.1) for maintaining usual ICS and 77.9 (27.7-110.3) for doubling ICS. Neither gender nor PEF at exacerbation were predictive of failure. Although doubling ICS was not an effective therapy overall, ICS dose at exacerbation were predictive of success in the doubling ICS arm (P = 0.04). Treatment failures when doubling daily ICS dose were more common if achieved fluticasone dose was less than 2000 mu g (three of 11, 73%) compared to 2000 mu g or greater (eight of eight, 37.5%). Increasing age and the presence of an upper respiratory tract infection (URTI) were predictive of failure with OS. Side-effects were more commonly reported with OS (52.6%) than doubling ICS (42.1%) or maintaining usual ICS (19.1%) with the most common being mood changes (36.8%), sleep disturbance (31.6%) and changes in appetite (26.3%). Conclusions: Doubling daily ICS dose per se is not effective for the treatment of mild to moderately severe exacerbations of asthma in adults. Success may depend on achieved ICS dose. Oral steroids are effective, but side-effects are common. A review of current guidelines may be warranted.

Testicular development of Zebu bulls after chronic treatment with a gonadotropin-releasing hormone agonist

The objective was to compare testis characteristics of Zebu bulls treated with the GnRH agonist, deslorelin, at different times and for different durations during their development. An additional objective was to determine the usefulness of a stain for the transcription factor GATA-binding protein 4 (GATA-4) as a specific marker for Sertoli cell nuclei in cattle. Bulls (54) were allocated to nine groups (n = 6) and received s.c. deslorelin implants as follows: G1 = from birth to 3 mo of age; G2 = from 3 to 6 mo; G3 = from 6 to 9 mo; G4 = from 9 to 12 mo; G5 = from birth to 15 mo; G6 = from 3 to 15 mo; G7 = from 6 to 15 mo; G8 = from 12 to 15 mo; and G9 (control) = no implant. Bulls were castrated at 19 mo of age. Paraffin sections (10 mu m) were subjected to quantitative morphometry and GATA-4 immunohistochemistry. At castration, all bulls in the control group (6/6) had attained puberty (scrotal circumference ! 28 cm), whereas a smaller proportion (P < 0.05) had reached puberty in G2 (2/5) and G6 (1/ 6). Bulls in G2 and G6 also had a lesser (P < 0.05) testis weight compared with the control group. Total volume of seminiferous epithelium and total daily sperm production in G2 and G6 were only half that observed in the control group. Spermatids were observed in less than 50% of seminiferous tubules in G2, G6, and G7 compared with 82% in the control group (P < 0.05). Staining for GATA-4 was specific for and abundant in the Sertoli cell nucleus in both pre- and postpubertal bulls, and no other cell nucleus inside the seminiferous tubule was positive for GATA-4. Total number of Sertoli cells was not affected by treatment (P = 0.45), but nuclear volume was smaller in G2 and G6 (P < 0.05) compared with the control group. In conclusion, treatment of Zebu bulls with deslorelin had no apparent beneficial effect on testis development and delayed puberty when treatment was initiated at 3 mo of age. Staining for GATA-4 was a useful method for identifying and quantifying Sertoli cell nuclei in both pre- and postpubertal bulls.

The effect of pH on the competition between polyphosphate-accumulating organisms and glycogen-accumulating organisms

In enhanced biological phosphorus removal (EBPR) processes, glycogen-accumulating organisms (GAOs) may compete with polyphosphate-accumulating organisms (PAOs) for the often-limited carbon substrates, potentially resulting in disturbances to phosphorus removal. A detailed investigation of the effect of pH on the competition between PAOs and GAOs is reported in this study. The results show that a high external pH (similar to 8) provided PAOs with an advantage over GAOs in EBPR systems. The phosphorus removal performance improved due to a population shift favouring PAOs over GAOs, which was shown through both chemical and microbiological methods. Two lab-scale reactors fed with propionate as the carbon source were subjected to an increase in pH from 7 to 8. The phosphorus removal and PAO population (as measured by quantitative fluorescence in situ hybridisation analysis of Candidatus Accumulibacter phosphatis) increased in each system, where the PAOs appeared to out-compete a group of Alphaproteobacteria GAOs. A considerable improvement in the P removal was also observed in an acetate fed reactor, where the GAO population (primarily Candidatus Competibacter phosphatis) decreased substantially after a similar increase in the pH. The results from this study suggest that pH could be used as a control parameter to reduce the undesirable proliferation of GAOs and improve phosphorus removal in EBPR systems. (c) 2005 Elsevier Ltd. All rights reserved.

Optimisation of poly-b-hydroxyalkanoate analysis using gas chromatography for enhanced biological phosphorus removal systems

Poly-beta-hydroxyalkanoate (PHA) is a polymer commonly used in carbon and energy storage for many different bacterial cells. Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), store PHA anaerobically through metabolism of carbon substrates such as acetate and propionate. Although poly-beta-hydroxybutyrate (PHB)and poly-beta-hydroxyvalerate (PHV) are commonly quantified using a previously developed gas chromatography (GC) method, poly-beta-hydroxy-2-methyl valerate (PH2MV) is seldom quantified despite the fact that it has been shown to be a key PHA fraction produced when PAOs or GAOs metabolise propionate. This paper presents two GC-based methods modified for extraction and quantification of PHB, PHV and PH2MV from enhanced biological phosphorus removal (EBPR) systems. For the extraction Of PHB and PHV from acetate fed PAO and GAO cultures, a 3% sulfuric acid concentration and a 2-20 h digestion time is recommended, while a 10% sulfuric acid solution digested for 20 h is recommended for PHV and PH2MV analysis from propionate fed EBPR systems. (c) 2005 Elsevier B.V. All rights reserved.

Effects of vehicle and region of application on absorption of hydrocortisone through canine skin

Objective-To determine the effects of various vehicles on the penetration and retention of hydrocortisone applied to canine skin. Sample Population-20 canine skin samples obtained from the thorax, neck, and groin regions of 5 Greyhounds. Procedure-Skin was harvested from dogs after euthanasia and stored at -20 degrees C until required. The skin was then defrosted and placed into diffusion cells, which were maintained at approximately 32 degrees C by a water bath. Saturated solutions of hydrocortisone that contained trace amounts of radiolabelled [C-14]-hydrocortisone in each vehicle (ie, PBS solution [PBSS] alone, 50% ethanol [EtOH] in PBSS [wt/wt], and 50% propylene glycol in PBSS [wt/wt]) were applied to the outer (stratum corneum) surface of each skin sample, and aliquots of receptor fluid were collected for 24 hours and analyzed for hydrocortisone. Results-The maximum flux of hydrocortisone was significantly higher for all sites when dissolved in a vehicle containing 50% EtOH, compared with PBSS alone or 50% propylene glycol, with differences more prominent in skin from the neck region. In contrast, higher residues of hydrocortisone were found remaining within the skin when PBSS alone was used as a vehicle, particularly in skin from the thorax and neck. Conclusions and Clinical Relevance-Penetration of topically applied hydrocortisone is enhanced when EtOH is used in vehicle formulation. Significant regional differences (ie, among the thorax, neck, and groin areas) are also found in the transdermal penetration and skin retention of hydrocortisone. Variability in clinical response to hydrocortisone can be expected in relation to formulation design and site of application.

Opposite effects of androgen receptor CAG repeat length on increased risk of left-handedness in males and females

Prenatal exposure to testosterone has been hypothesised to effect lateralization by influencing cell death in the foetal brain. Testosterone binds to the X chromosome linked androgen receptor, which contains a polymorphic polyglutamine CAG repeat, the length of which is positively correlated with testosterone levels in males, and negatively correlated in females. To determine whether the length of the androgen receptor mediates the effects of testosterone on laterality, we examined the association between the number of CAG repeats in the androgen receptor gene and handedness for writing. Association was tested by adding regression terms for the length of the androgen receptor alleles to a multi-factorial-threshold model of liability to left-handedness. In females we found the risk of left-handedness was greater in those with a greater number of repeats (p=0.04), this finding was replicated in a second independent sample of female twins (p=0.014). The length of the androgen receptor explained 6% of the total variance and 24% of the genetic variance in females. In males the risk of left-handedness was greater in those with fewer repeats (p=0.02), with variation in receptor length explaining 10% of the total variance and 24% of the genetic variance. Thus, consistent with Witelson's theory of testosterone action, in all three samples the likelihood of left handedness increased in those individuals with variants of the androgen receptor associated with lower testosterone levels.