Genotype-by-environment interaction of growth traits in rainbow trout (Oncorhynchus mykiss): a continental scale study.

Rainbow trout is a globally important fish species for aquaculture. However, fish for most farms worldwide are produced by only a few breeding companies. Selection based solely on fish performance recorded at a nucleus may lead to lower-than-expected genetic gains in other production environments when genotype-by-environment (G × E) interaction exists. The aim was to quantify the magnitude of G × E interaction of growth traits (tagging weight; BWT, harvest weight; BWH, and growth rate; TGC) measured across 4 environments, located in 3 different continents, by estimating genetic correlations between environments. A total of 100 families, of at least 25 in size, were produced from the mating 58 sires and 100 dams. In total, 13,806 offspring were reared at the nucleus (selection environment) in Washington State (NUC) and in 3 other environments: a recirculating aquaculture system in Freshwater Institute (FI), West Virginia; a high-altitude farm in Peru (PE), and a cold-water farm in Germany (GER). To account for selection bias due to selective mortality, a multitrait multienvironment animal mixed model was applied to analyze the performance data in different environments as different traits. Genetic correlation (rg) of a trait measured in different environments and rg of different traits measured in different environments were estimated. The results show that heterogeneity of additive genetic variances was mainly found for BWH measured in FI and PE. Additive genetic coefficient of variation for BWH in NUC, FI, PE, and GER were 7.63, 8.36, 8.64, and 9.75, respectively. Genetic correlations between the same trait in different environments were low, indicating strong reranking (BWT: rg = 0.15 to 0.37, BWH: rg = 0.19 to 0.48, TGC: rg = 0.31 to 0.36) across environments. The rg between BWT in NUC and BWH in both FI (0.31) and GER (0.36) were positive, which was also found between BWT in NUC and TGC in both FI (0.10) and GER (0.20). However, rg were negative between BWT in NUC and both BWH (-0.06) and TGC (-0.20) in PE. Correction for selection bias resulted in higher additive genetic variances. In conclusion, strong G × E interaction was found for BWT, BWH, and TGC. Accounting for G × E interaction in the breeding program, either by using sib information from testing stations or environment-specific breeding programs, would increase genetic gains for environments that differ significantly from NUC.

Defining desired genetic gains for rainbow trout breeding objective using analytic hierarchy process.

Distributing animals from a single breeding program to a global market may not satisfy all producers, as they may differ in market objectives and farming environments. Analytic hierarchy process (AHP) is used to estimate preferences, which can be aggregated to consensus preference values using weighted goal programming (WGP). The aim of this study was to use an AHP-WGP based approach to derive desired genetic gains for rainbow trout breeding and to study whether breeding trait preferences vary depending on commercial products and farming environments. Two questionnaires were sent out. Questionnaire-A (Q-A) was distributed to 178 farmers from 5 continents and used to collect information on commercial products and farming environments. In this questionnaire, farmers were asked to rank the 6 most important traits for genetic improvement from a list of 13 traits. Questionnaire B (Q-B) was sent to all farmers who responded to Q-A (53 in total). For Q-B, preferences of the 6 traits were obtained using pairwise comparison. Preference intensity was given to quantify (in % of a trait mean; G%) the degree to which 1 trait is preferred over the other. Individual preferences, social preferences, and consensus preferences (Con-P) were estimated using AHP and WGP. Desired gains were constructed by multiplying Con-P by G%. The analysis revealed that the 6 most important traits were thermal growth coefficient (TGC), survival (Surv), feed conversion ratio (FCR), condition factor (CF), fillet percentage (FIL%), and late maturation (LMat). Ranking of traits based on average Con-P values were Surv (0.271), FCR (0.246), TGC (0.246), LMat (0.090), FIL% (0.081), and CF (0.067). Corresponding desired genetic gains (in % of trait mean) were 1.63, 1.87, 1.67, 1.29, 0.06, and 0.33%, respectively. The results from Con-P values show that trait preferences may vary for different types of commercial production or farming environments. This study demonstrated that combination of AHP and WGP can be used to derive desired gains for a breeding program and to quantify differences due to variations market demand or production environment.

Early onset of embryonic mortality in sub-fertile families of rainbow trout (Oncorhynchus mykiss).

Survival during early embryonic development is highly variable in oviparous fishes and appears to be related to events associated with the female at the time of ovulation and spawning. The goal of this study was to identify critical periods of mortality associated with early embryonic development in egg batches from female rainbow trout (Oncorhynchus mykiss) that were checked for ovulation every 5-7 days. The experiment was designed to specifically remove post-ovulatory ageing and reduce paternal variability. Embryo viability in 269 single-pair-mated families was systematically tracked at the following five stages: second cleavage (0.5 days post fertilisation (dpf)), elevated blastula (2.5 dpf), embryonic shield (6 dpf), embryonic keel (9 dpf), and retinal pigmentation (19 dpf). At each of the five stages families with embryo viability assessments of <80% were classed as sub-fertile, whereas those with >80% embryo viability were classed as fertile. Embryo viability in sub-fertile families was distinctly reduced at 0.5 dpf, in contrast to fertile families, but remained constant from that point through to 19 dpf. These results suggest that the critical period of early embryonic mortality in sub-fertile families of rainbow trout parallels events that occur at or shortly after fertilisation and is independent of post-ovulatory aging.

Gonadal regeneration in masculinized female or steroid-treated rainbow trout (Oncorhynchus mykiss).

In salmonids, the development of an indifferent gonad into a testis or an ovary is normally determined chromosomally but can be reversed or changed by the administration of exogenous steroids during specific times in embryonic development. Because the gonads of sexually mature rainbow trout (RBT) are capable of regeneration following surgical removal and since regeneration of some tissue involves dedifferentiation, the objective of this experiment was to determine if the phenotypic sex of RBT gonads could be reversed during the regenerative process. In experiment 1, male RBT were surgically gonadectomized (Gx) or left intact and subsequently treated with estradiol-17beta, a steroid that feminizes male RBT embryos. All Gx males regenerated testicular tissue regardless of treatment. Likewise, the gonads of sham-operated, intact fish treated with exogenous estrogen showed no evidence of sex-reversal. In experiment 2, testes from masculinized females (XX genotype; male phenotype) were surgically removed. In all cases, only testicular tissue was regenerated in the masculinized females. Taken together, these results are consistent with the conclusion that gonads of salmonid fishes are not susceptible to sex-reversing stimuli during the regenerative process and that gonadal regeneration in salmonids is a result of cellular proliferation of the remaining gonadal remnant.

Addressing domestic violence through maternity services: policy and practice.

OBJECTIVE: to explore current policies and practices in maternity units that aim to identify, assess and support women experiencing domestic violence. DESIGN AND SETTING: a postal survey, conducted between June and October 1999, of all NHS Trusts in England and Wales that provided maternity services. PARTICIPANTS: Heads of Midwifery or the midwife with expertise or interest in domestic violence in each Trust. MAIN OUTCOME MEASURES: use of written policies and agreed practices for identifying and referring women experiencing domestic violence, such as availability of information, routine questioning of all women and offering women an appointment without their partner. RESULTS: 87% (183) of the 211 NHS Trusts providing maternity care participated in the survey. Twelve per cent of units had written policies for identifying women experiencing domestic violence, and a further 30% had some form of agreed practice. Less than half of maternity units routinely offered women an appointment without their partner, and just over half displayed material about domestic violence in places where women receive maternity care. Only three units had undertaken audit on their domestic violence practices. CONCLUSIONS: there is considerable variability around England and Wales in policies and practices related to domestic violence. It is evident that clear guidelines for identification and referral, training, audit and the integration of domestic violence policies with child protection and other policies are necessary to fully address the issues.

Caregiving tasks among family caregivers of patients with lung cancer.

PURPOSE/OBJECTIVES: To describe family caregivers' perceptions of time spent and difficulty experienced with performing specific caregiving tasks for patients with lung cancer. To compare adult child and spousal caregivers in relation to time and difficulty of tasks. DESIGN: A secondary analysis of data from a study using a cross-sectional, descriptive, comparison design. SETTING: A university outpatient oncology center, two veterans administration outpatient clinics, and a private outpatient oncology practice. SAMPLE: 78 family caregivers of patients with lung cancer (62 spouses and 16 adult children). METHODS: Data that previously had been collected using a structured interview guide were analyzed using descriptive statistics, comparison of item means, and multivariate analysis of variance. MAIN RESEARCH VARIABLES: Time and difficulty with caregiving tasks. FINDINGS: The most time-consuming tasks for adult children and spouses were providing emotional support, transportation, and monitoring symptoms. The most difficult duties were emotional support, behavioral management, monitoring symptoms, and household tasks. Time and difficulty of tasks did not differ significantly between adult child and spousal caregivers. CONCLUSIONS: Some caregivers may require guidance in providing transportation, emotional support, behavioral management, and symptom management. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurses can make a significant impact in assisting family members in providing care by addressing the provision of transportation, emotional support, behavioral management, and symptom management.

Type III units in the gerbil dorsal cochlear nucleus may be spectral notch detectors.

Broadband sounds originating in the median plane are thought to be localized by neural processing of spectral notches introduced by the filtering action of the pinnae. Previous studies (Nelken, I., and E. D. Young. J. Neurophysiol. 71:2446-2462, 1994: Spirou, G. A., and E. D. Young. ibid. 66: 1750-1768. 1991) suggested that type IV units in decerebrate cat dorsal cochlear nucleus (DCN) are functional detectors of these spectral notches. Intracellular marking studies by Ding et al. (Ding, J., T. E. Benson, and H. F. Voigt. J. Neurophysiol. 82:3434-3457, 1999) have shown that type III units in gerbil arise from the DCN's principal output neurons, which are thought to have type IV unit properties in cat. A relative paucity of type IV units in the decerebrate gerbil (Davis. K. A., J. Ding, T. E. Benson, and H. F. Voigt. J. Neurophysiol. 75: 1411-1431, 1996) has motivated this study of spectral notch sensitivity in the gerbil DCN. Responses to notch noise stimuli were recorded from 15 gerbil type III units to investigate whether these units may function as spectral notch detectors. For narrow notch noise stimuli, all 15 units showed excitatory responses. For progressively wider notches, the discharge rate of 13/15 units became inhibited. As the maximum limits of notch width were approached, 11/15 units showed some degree of recovery from this inhibition. This response pattern in gerbil type III units possesses the salient features of notch noise responses in cat type IV units and implicates type III units in gerbilline spectral notch detection processes.

Efficacy and safety of famciclovir for treating mucocutaneous herpes simplex infection in HIV-infected individuals. Collaborative Famciclovir HIV Study Group.

OBJECTIVE: To compare the efficacy and safety of 7 days' treatment with famciclovir 500 mg twice a day versus acyclovir 400 mg five times a day, for mucocutaneous herpes simplex virus (HSV) infection in HIV-infected individuals. DESIGN: Randomized, double-blind, parallel-group study to demonstrate equivalence for the primary efficacy parameter. SETTING: Forty-eight hospital-based or specialist public-health clinics in 12 countries. PATIENTS: Two-hundred and ninety-three HIV-positive patients with recurrent HSV infection (orolabial or genital) starting treatment within 48 h of first appearance of herpetic lesions. MAIN OUTCOME MEASURES: Proportion of patients developing new lesions during treatment (primary outcome measures); Time to complete healing of lesions, time to cessation of viral shedding, time to loss of lesion-associated symptoms, number of withdrawals due to treatment failure (secondary outcome measures). RESULTS: Equivalence was defined prospectively and famciclovir was equivalent to acyclovir in preventing new lesion formation: new lesions occurred in 16.7% and 13.3% of patients, respectively [difference, 3.4%; 95% confidence interval (CI), -4.8-11.5]. The groups were comparable in time to complete healing (median 7 days for both groups; hazard ratio, 1.01; 95% CI, 0.79-1.29; P = 0.95), cessation of viral shedding (median of 2 days [hazard ratio = 0.93; 95% C.I. 0.68, 1.27; p = 0.64]), and loss of lesion-associated symptoms (median 4 days; hazard ratio, 0.99; 95% CI, 0.75-1.30; P = 0.93). Similar numbers in each group withdrew because of treatment failure. There were no differences between groups in the incidence of adverse events. CONCLUSIONS: Famciclovir given twice a day is as effective and well tolerated as high-dose acyclovir for mucocutaneous HSV infections in HIV-infected individuals, and has the convenience of less frequent dosing.

Development of cytotoxic antibodies following renal allograft transplantation is associated with reduced graft survival due to chronic vascular rejection.

We prospectively followed 64 patients who had had no cytotoxic antibodies prior to first cadaveric renal allograft transplantation for post-transplant antibodies. During a mean follow-up period of 62 months (range 45-92) cytotoxic antibodies developed in 36 patients (56%). Sixteen grafts were lost due to chronic vascular rejection in the group of patients who developed antibodies compared to two in those who remained antibody negative, P < 0.01. Renal function was worse in the antibody-positive group, median serum creatinine 215 mumol/l (131-256) (interquartile range) versus 111 mumol/l (98-127) in the antibody-negative group, P = 0.002, and creatinine clearance 39 ml/min (25-55) versus 90 ml/min (55-104), P < 0.001. There were no significant differences in immunosuppressive protocol, HLA-mismatching, blood transfusion history, the number of acute rejection episodes, mean arterial blood pressure, or proteinuria between the groups. The presence of cytotoxic antibodies predated the classical manifestations of chronic vascular rejection. This suggests that humoral mechanisms may play a role in the development of chronic vascular rejection.

Low sodium injury in the hippocampal slice is mediated through NMDA receptors.

Perfusion of hippocampal slices with normoxic medium containing no added sodium resulted in a rapid loss of the CA1 population spike, with only 35 +/- 10% (S.E.M.) (P < 0.001) recovery after a 15 min exposure. This injury was prevented by the non-competitive N-methyl-D-aspartate (NMDA) antagonist MK-801 (93 +/- 4% recovery, P < 0.001), suggesting that low sodium injury may be mediated by opening of the NMDA receptor-associated ionic channels, possibly secondary to the well known sodium dependency of transmitter uptake systems. By contrast, slice perfusion with a medium moderately low in sodium (26 mM) produced only slight injury to the CA1 population spike under normoxic conditions (76 +/- 8% recovery) and provided no protection against hypoxic injury. Low chloride medium also provided no protection against hypoxic injury.

Risk factors for tornado injuries.

Tornadoes in North and South Carolina on 28 March 1984 caused 252 people to be injured seriously enough to require hospitalization and 59 to be killed. To evaluate risk factors, we gathered information on 238 (94%) of those hospitalized and 46 (78%) of those killed. Those hospitalized or deceased had statistically significantly more deep cuts, concussions, unconsciousness and broken bones than those with them at the time of the tornado who were not hospitalized or killed. People living in mobile homes were more likely to be hospitalized or die than people occupying conventional houses. Other risk factors for hospitalization or death included advanced age (60+ years), no physical protection (not having been covered with a blanket or other object), having been struck by broken window glass or other falling objects, home lifted off its foundation, collapsed ceiling or floor, or walls blown away. More awareness of the tornado risk before it strikes and better adherence to tornado protection guidelines could reduce injuries and deaths in the future.

Changes of amino acid gradients in brain tissues induced by microwave irradiation and other means.

Focused microwave irradiation to the head (FMI) has been used extensively by neurochemists for rapid inactivation of enzymatic activity in brain tissues and the preservation, for in vitro analysis, of in vivo substrate concentrations. Periodically the suitability of this technique for regional studies has been questioned. Evidence has now been obtained, on the basis of altered concentration gradients for GABA and taurine from the Substantia Nigra (SN) to an Adjacent Dorsal Area (ADJ), that FMI not only inactivates enzymes, but also facilitates rapid diffusion of small molecules from areas of high concentrations to adjacent areas of lower concentration. To a lesser extent, the implantation of plastic injection cannulas also decreased these concentration gradients. These results offer clear evidence that FMI is ill suited and unreliable for studies designed to map and compare the "in vivo" regional concentrations of diffusible organic molecules (such as amino acids) in brain tissues. Any invasive technique that compromises membrane barriers is likely to produce smaller similar effects.

Alcohol and fatal injuries: temporal patterns.

Although alcohol use has been established as a risk factor for injuries associated with motor vehicle crashes, the role of alcohol for other unintentional and intentional injuries is less defined. A review of 102,401 deaths investigated by North Carolina medical examiners in the period 1973-1983 characterized the temporal patterns of ethyl alcohol in unintentional injury fatalities, suicides, homicides, and persons who died of natural or unknown causes. Victims of homicides (85.9%) and suicides (77.7%) were tested for alcohol more frequently than were fatalities resulting from unintentional injury (67.5%) or natural causes (61.6%). Alcohol was present in 62.8% of homicide victims, 48.6% of unintentional injury fatalities, 35.3% of suicides, and 14.4% of deaths from natural causes. The percentage of alcohol-associated deaths for each manner of death showed little yearly or seasonal variation. Alcohol was most frequently detected in persons fatally injured on the weekend and from 6 PM to 6 AM. This study highlights the magnitude of alcohol's role in intentional and unintentional injuries, especially for persons injured at night and on weekends.

A hypoxic injury potential in the hippocampal slice.

In rat hippocampal slices, neurons in the stratum pyramidale of the CA1 were stimulated orthodromically and antidromically while the resultant extracellular population spikes were monitored. Hypoxic conditions were then induced. After disappearance of the orthodromic population spike, a second orthodromic population spike appeared. We have titled this the hypoxic injury potential since it reflects the onset of permanent injury to neurons in area CA1 of the hippocampus.

Hemolytic uremic syndrome and diarrhea associated with Escherichia coli O157:H7 in a day care center.

Three cases of hemolytic uremic syndrome with bloody diarrhea occurred during an outbreak of diarrheal illness in children aged 4 months to 9 years who attended a day care center. Thirty-six (34%) of 107 had diarrhea (three or more loose or watery stools in 24 hours) lasting greater than or equal to 3 days. Thirty-one (48%) of 64 children younger than 4 years of age but only (12%) of 43 in the older classes became ill (relative risk 4.0, P less than 0.001). Eleven (31%) of the 36 children with diarrhea had blood in their stools. Sequential movement of illness from class to class was consistent with person-to-person spread. Ten (18%) of 56 family members of ill children but only one of 45 family members of well children younger than 4 years of age developed a diarrheal illness (P less than 0.05). Escherichia coli O157:H7 was detected in two of eight stool specimens from children who had bloody diarrhea (one with hemolytic uremic syndrome), two of seven with nonbloody diarrhea, and none of nine who remained well. All three stool specimens obtained at less than or equal to 6 days compared with one of nine obtained at greater than 6 days after onset yielded this organism (P less than 0.02). E. coli O157:H7 can cause hemolytic uremic syndrome and both nonbloody and bloody diarrhea, and can spread within families and through modes other than foodborne transmission.

Production of androgenetic diploid rainbow trout.

Haploid androgenesis was induced in rainbow trout (Salmo gairdneri) when eggs were irradiated with 60Co gamma radiation prior to fertilization. Diploidy was restored to the androgenetic haploid zygotes by suppression of first cleavage division using hydrostatic pressure. Peak survival in the androgenetic diploid lots (32.5-38.9 percent of control) occurred when a pressure shock of 9000 pounds per square inch lasting from one to three minutes was applied to the eggs 345 minutes post-fertilization. Chromosomal analysis confirmed diploidy in the androgenetic individuals and suggested that YY rainbow trout are viable to at least the "eyed stage" of development. Inheritance patterns at two loci confirmed all-paternal inheritance. The relatively high yields of completely homozygous androgenetic rainbow trout and the potential for the use of androgenesis in the production of inbred lines and in genetic studies indicate that androgenesis may become a valuable tool in fish research and breeding.

Residual paternal inheritance in gynogenetic rainbow trout: implications for gene transfer.

Pollen irradiation has recently been widely investigated as a method for differential gene transfer in plants. Using an albino color marker in rainbow trout (Salmo gairdneri), we have investigated whether irradiated sperm might be used in an analogous manner for gene transfer in fish. Our results indicate that paternal chromosome fragments are genetically active in gynogenetic offspring, but that these fragments may be lost during mitotic cell division, producing mosaic fish.

A comparison of three means of pressurized aerosol inhaler use.

The bronchodilator response to 200 micrograms of fenoterol hydrobromide using 3 different methods of inhalation from a pressurized aerosol metered-dose inhaler, was studied in 13 asthmatic patients. On 4 separate days and in random order, patients received either placebo aerosol or fenoterol aerosol delivered by the patients' own technique, delivered under supervision by a trained member of our staff, and delivered with a spacer device (Aerochamber) attached to the pressurized canister. There was no significant difference in the response to the 3 methods of active drug administration, but there was a significant difference (p less than 0.05) from the placebo control values. Thus, in this group of asthmatics the patients' own method of inhalation, using the standard dose of 200 micrograms of fenoterol from a pressurized aerosol metered-dose inhaler, appears to be as effective a means of bronchodilation as the other techniques used in this study.