Cage colour and post-harvest K+ concentration affect skin colour of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)

In an attempt to improve post-harvest skin colour in cultured Australian snapper Pagrus auratus, a two-factor experiment was carried out to investigate the effects of a short-term change in cage colour before harvest, followed by immersion in K⁺-enriched solutions of different concentrations. Snapper supplemented with 39 mg unesterified astaxanthin kg⁻¹ for 50 days were transferred to black (for 1 day) or white cages (for 1 or 7 days) before euthanasia by immersing fish in seawater ice slurries supplemented with 0, 150, 300, 450 or 600 mmol L⁻¹ K⁺ for 1 h. Each treatment was replicated with five snapper (mean weight=838 g) held individually within 0.2 m³ cages. L*, a* and b* skin colour values of all fish were measured after removal from K⁺ solutions at 0, 3, 6, 12, 24 and 48 h. After immersion in K⁺ solutions, fish were stored on ice. Both cage colour and K⁺ concentration significantly affected post-harvest skin colour (P<0.05), and there was no interaction between these factors at any of the measurement times (P>0.05). Conditioning dark-coloured snapper in white surroundings for 1 day was sufficient to significantly improve skin lightness (L*) after death. Although there was no difference between skin lightness values for fish held for either 1 or 7 days in white cages at measurement times up to 12 h, fish held in white cages for 7 days had significantly higher L* values (i.e. they were lighter) after 24 and 48 h of storage on ice than those held only in white cages for 1 day. K⁺ treatment also affected (improved) skin lightness post harvest although not until 24 and 48 h after removal of fish from solutions. Before this time, K⁺ treatment had no effect on skin lightness. Snapper killed by seawater ice slurry darkened (lower L*) markedly during the first 3 h of storage in contrast with all K⁺ treatments that prevented darkening. After 24 and 48 h of storage on ice, fish exposed to 450 and 600 mmol L⁻¹ K⁺ were significantly lighter than fish from seawater ice slurries. In addition, skin redness (a*) and yellowness (b*) were strongly dependent on K⁺ concentration. The initial decline in response to K⁺ was overcome by a return of a* and b* values with time, most likely instigated by a redispersal of erythrosomes in skin erythrophores. Fish killed with 0 mmol L⁻¹ K⁺ maintained the highest a* and b* values after death, but were associated with darker (lower L*) skin colouration. It is concluded that a combination of conditioning snapper in white surroundings for 1 day before harvest, followed by immersion in seawater ice slurries supplemented with 300–450 mmol L⁻¹ K⁺ improves skin pigmentation after >24 h of storage on ice.

Skin temperature as a noninvasive marker of haemodynamic and perfusion status in adult cardiac surgical patients : an observational study

Objective
Foot temperature has long been advocated as a reliable noninvasive measure of cardiac output despite equivocal evidence. The aim of this pilot study was to investigate the relationship between noninvasively measured skin temperature and the more invasive core-peripheral temperature gradients (CPTGs), against cardiac output, systemic vascular resistance, serum lactate, and base deficit.

Research methodology
The study was of a prospective, observational and correlational design. Seventy-six measurements were recorded on 10 adults postcardiac surgery. Haemodynamic assessments were made via bolus thermodilution. Skin temperature was measured objectively via adhesive probes, and subjectively using a three-point scale.

Setting
The study was conducted within a tertiary level intensive care unit.

Results
Cardiac output was a significant predictor for objectively measured skin temperature and CPTG (p = .001 and p = .004, respectively). Subjective assessment of skin temperature was significantly related to cardiac output, systemic vascular resistance, and serum lactate (p < .001, respectively).

Conclusions
These results support the utilisation of skin temperature as a noninvasive marker of cardiac output and perfusion. The use of CPTG was shown to be unnecessary, given the parallels in results with the less invasive skin temperature parameters. A larger study is however required to validate these findings.

Skin prick test can identify eczematous infants at risk of asthma and allergic rhinitis

Background: Assessment of allergic sensitization is not routinely performed in infants and young children with eczema.

Objective: To determine whether infants who have atopic eczema (with sensitization) are at a greater risk of developing asthma and allergic rhinitis (AR) than those with non-atopic eczema (without concurrent sensitization).

Methods: The presence of eczema was prospectively documented until 2 years of age in a birth cohort of 620 infants with a family history of atopic disease. Sensitization status was determined by skin prick tests (SPTs) at 6, 12, and 24 months using six common allergens. Interviews were conducted at 6 and 7 years to determine the presence of asthma and AR.

Results: Within the first 2 years of life, 28.7% of the 443 children who could be classified had atopic eczema: 20.5% had non-atopic eczema, 19.0% were asymptomatic but sensitized and 31.8% were asymptomatic and not sensitized. When compared with children with non-atopic eczema in the first 2 years of life, children with atopic eczema had a substantially greater risk of asthma [odds ratio (OR)=3.52, 95% confidence interval=1.88–6.59] and AR (OR=2.91, 1.48–5.71). The increased risk of asthma was even greater if the infant had a large SPT (OR=4.61, 2.34–9.09) indicative of food allergy. There was no strong evidence that children with non-atopic eczema had an increased risk of asthma or AR compared with asymptomatic children.

Conclusion: In children with eczema within the first 2 years of life, SPT can provide valuable information on the risk of childhood asthma and AR.

Effects of dietary astaxanthin concentration and feeding period on the skin pigmentation of Australian snapper Pagrus auratus (Bloch & Schneider, 1801)

A single-factor experiment was conducted to investigate the effects of dietary astaxanthin concentration on the skin colour of snapper. Snapper (mean weight=129 g) were held in white cages and fed one of seven dietary levels of unesterified astaxanthin (0, 13, 26, 39, 52, 65 or 78 mg astaxanthin kg⁻¹) for 63 days. Treatments comprised four replicate cages, each containing five fish. The skin colour of all fish was quantified using the CIE L^*, a^*, b^* colour scale after 21, 42 and 63 days. In addition, total carotenoid concentrations of the skin of two fish cage−1 were determined after 63 days. Supplementing diets with astaxanthin strongly affected redness (a^*) and yellowness (b^*) values of the skin at all sampling times. After 21 days, the a^* values increased linearly as the dietary astaxanthin concentration was increased before a plateau was attained between 39 and 78 mg kg⁻¹. The b^* values similarly increased above basal levels in all astaxanthin diets. By 42 days, a^* and b^* values increased in magnitude while a plateau remained between 39 and 78 mg kg⁻¹. After 63 days, there were no further increases in measured colour values, suggesting that maximum pigmentation was imparted in the skin of snapper fed diets >39 mg kg⁻¹ after 42 days. Similarly, there were no differences in total carotenoid concentrations of the skin of snapper fed diets >39 mg kg⁻¹ after 63 days. The plateaus that occurred in a^* and b^* values, while still increasing in magnitude between 21 and 42 days, indicate that the rate of astaxanthin deposition in snapper is limited and astaxanthin in diets containing >39 mg astaxanthin kg⁻¹ is not efficiently utilized. Astaxanthin retention after 63 days was greatest from the 13 mg kg⁻¹ diet; however, skin pigmentation was not adequate. An astaxanthin concentration of 39 mg kg⁻¹ provided the second greatest retention in the skin while obtaining maximum pigmentation. To efficiently maximize skin pigmentation, snapper growers should commence feeding diets containing a minimum of 39 mg unesterified astaxanthin kg⁻¹ at least 42 days before sale.

Changes in skin colour and cortisol response of Australian snapper Pagrus auratus (Bloch & Schneider, 1801) to different background colours

A two-factor experiment was carried out to investigate the change in skin colour and plasma cortisol response of cultured Australian snapper Pagrus auratus to a change in background colour. Snapper (mean weight=437 g) were held in black or white tanks and fed diets containing 39 mg unesterified astaxanthin kg⁻¹ for 49 days before being transferred from white tanks to black cages (WB) or black tanks to white cages (BW). Skin colour values [L^* (lightness), a^* (redness) and b^* (yellowness)] of all snapper were measured at stocking (t=0 days) and from cages of fish randomly assigned to each sampling time at 0.25, 0.5, 1, 2, 3, 5 and 7 days. Plasma cortisol was measured in anaesthetized snapper following colour measurements at 0, 1 and 7 days. Fish from additional black-to-black (BB) and white-to-white (WW) control treatments were also sampled for colour and cortisol at those times. Rapid changes occurred in skin lightness (L^* values) after altering background colour with maximum change in L^* values for BW and WB treatments occurring within 1 day. Skin redness (a*) of BW snapper continued to steadily decrease over the 7 days (a*=7.93 × e^{−0.051 × time}). Plasma cortisol concentrations were highest at stocking when fish were held at greater densities and were not affected by cage colour. The results of this study suggest that transferring dark coloured snapper to white cages for 1 day is sufficient to affect the greatest benefit in terms of producing light coloured fish while minimizing the reduction in favourable red skin colouration.

Economic evaluation of skin cancer prevention in Australia

Objectives
Australia has the highest incidence of skin cancer in the world, despite prevention campaigns being implemented since the early 1980s. This study assesses the cost-effectiveness of a skin cancer prevention program (named SunSmart) since it was introduced, together with its potential cost-effectiveness as an upgraded and ongoing national program.

Methods
The reduction in melanoma incidence attributable to SunSmart was modelled as the primary end-point. Historical expenditures on SunSmart were obtained from representative Australian states in three latitude zones. Melanoma incidence rates from these states were used to model key health outcomes. Non-melanoma skin cancer was modelled separately based on national survey results.

Results
We estimate that SunSmart has averted 28,000 disability-adjusted life-years (DALYs), equivalent to 22,000 life-years saved, in the state of Victoria since its introduction in 1988, as well as saving money from cost offset in skin cancer management (dominant). An upgraded national program for the next 20 years is estimated to avert 120,000 DALYs, with associated reductions in the use of health care resources. It remains a dominant intervention in which every dollar invested in SunSmart will return an estimated AU$2.30.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be an excellent value for money.

Economic evaluation of a skin cancer prevention program in Australia : past achievements and future prospects

Objectives
Australia has the highest incidence of skin cancer in the world. Skin cancer prevention campaigns have been implemented in Australia for over two decades. The most notable is under the brand name, SunSmart. The aim of the current study is to assess the cost-effectiveness of SunSmart in the past and the potential cost-effectiveness of an ongoing national SunSmart program with optimal investment in the future.

Methods
An economic evaluation from a health sector perspective was conducted using the reduction in skin cancer incidence attributable to the SunSmart program modelled as the primary end-point. Historical SunSmart program expenditures were obtained from three representative states in three latitude zones, covering different levels of UVR exposure. Melanoma incidence rates from the three representative state cancer registers were used to model the health outcomes. Program effectiveness was assessed by the comparison between the well-resourced SunSmart state (Victoria) and the under-invested states (New South Wales and Queensland). Non-Melanoma Skin Cancer (NMSC) was modelled based on national survey results. 2003 was chosen as the reference year and future costs/outcomes over a 20 year time horizon were discounted at 3%.
The future level of investment in a national SunSmart was chosen to strengthen current practice by increasing current investment to a realistic and achievable level. This conservative increase in investment (expressed as ‘$ per capita’) reflected the investment level that has been achieved in Victoria over sustained periods. To model the potential cost-effectiveness of an upgraded national SunSmart program, a conservative approach was taken, whereby the same magnitude of effectiveness from 1988 to 2003 was applied to future skin cancer incidence.

Results
SunSmart in Victoria has saved 22,300 life-years, averted 27,900 disability-adjusted life-years(DALYs)(discounted) since its introduction in 1988 and achieved an incremental cost-effectiveness ratio (ICER) of $AUD 680 per life-year saved (LYS) and $AUD 540 per DALY averted. When the cost-offset from the estimated reduction in skin cancer treatment costs were taken into account, SunSmart achieved ‘dominance’. The net cost of SunSmart in the past was an estimated saving of $AUD 93 million. An upgraded national SunSmart for the next 20 years would save 91,000 life-years and avert 122,000 DALYs (discounted), involving an increased investment level from the current $AUD 0.07 per capita to the historical average of $AUD 0.28 per capita. The ICER for the upgraded SunSmart program was estimated at $AUD 940 per LYS and $AUD 700 per DALY averted. When the cost-offset is included, the program achieves dominance with a cost saving of $AUD 115 million – an estimated $AUD 2.32 return for every dollar invested between 2003 and 2022.

Conclusions
This study demonstrates that a sustained modest investment in skin cancer control is likely to be excellent value-for-money. While the available data base is certainly not prefect, key parameters would have to change dramatically for this conclusion to be challenged.

Impaired muscle Ca2+ and K+ regulation contribute to poor exercise performance post-lung transplantation

Lung transplant recipients (LTx) exhibit marked peripheral limitations to exercise. We investigated whether skeletal muscle Ca2+ and K+ regulation might be abnormal in eight LTx and eight healthy controls. Peak oxygen consumption and arterialized venous plasma [K+] (where brackets denote concentration) were measured during incremental exercise. Vastus lateralis muscle was biopsied at rest and analyzed for sarcoplasmic reticulum Ca2+ release, Ca2+ uptake, and Ca2+-ATPase activity rates; fiber composition; Na+-K+-ATPase (K+-stimulated 3-O-methylfluorescein phosphatase) activity and content ([3H]ouabain binding sites); as well as for [H+] and H+-buffering capacity. Peak oxygen consumption was 47% less in LTx (P < 0.05). LTx had lower Ca2+ release (34%), Ca2+ uptake (31%), and Ca2+-ATPase activity (25%) than controls (P < 0.05), despite their higher type II fiber proportion (LTx, 75.0 ± 5.8%; controls, 43.5 ± 2.1%). Muscle [H+] was elevated in LTx (P < 0.01), but buffering capacity was similar to controls. Muscle 3-O-methylfluorescein phosphatase activity was 31% higher in LTx (P < 0.05), but [3H]ouabain binding content did not differ significantly. However, during exercise, the rise in plasma [K+]-to-work ratio was 2.6-fold greater in LTx (P < 0.05), indicating impaired K+ regulation. Thus grossly subnormal muscle calcium regulation, with impaired potassium regulation, may contribute to poor muscular performance in LTx.

Factors influencing skin colour in cultured Australian snapper Pagrus auratus

Sea cage production of Australian snapper has been largely constrained during the past decade by abnormal skin pigmentation which has negatively impacted marketability. The research described in this study identified dietary, environmental and harvesting techniques to successfully alter skin colour to potentially improve the viability of snapper aquaculture in Australia.