Development of a regulatory testing procedure to study the metabolism of pesticides in farmed fish

BACKGROUND

Diets used in commercial fish farming use significant proportions of crop-derived commodities, and it is important to understand the potential for transfer of any pesticide residues on the crop into edible tissues in fish. It is a current requirement in the EU that fish metabolism studies must be performed when a pesticide is used in crops where commodities or processed fractions are fed to farmed fish. Fish metabolism studies in both rainbow trout and common carp have been carried out, following the new working document on the nature of pesticide residues in fish using (14) C-labelled pesticide.

RESULTS

The ingestion of experimental diets by rainbow trout and common carp resulted in the uptake and metabolism of the test item, as shown by liquid scintillation counting combined with radio-thin-layer chromatography. The metabolite profiles for trout and carp were qualitatively similar regarding the main residue. However, species-specific differences were found regarding the remaining residue with rainbow trout showing additional metabolites in comparison to carp.

CONCLUSIONS

Metabolism studies for regulatory purposes can be carried out with both fish species under laboratory conditions. The experimental design reported is suitable for quantifying the transfer of residues to edible tissues and enables characterisation of the chemical nature of residues.

Investigation into feed preparation for regulatory fish metabolism studies

BACKGROUND

Test diets used in fish metabolism studies for regulatory purposes must be homogenously fortified with the radiolabelled test substance and stable with respect to leaching. Standard fish food, as used in commercial fish farming, should also be used in fish metabolism studies. Therefore, suitable spiking and coating procedures are required to ensure the correct dosing of the fish during the experiment.

RESULTS

Methods for the homogeneous, safe and efficient application of radiolabelled test items to the surface of commercial feeding pellets were developed. Leaching studies showed that test items of low lipophilicity applied to feeding pellets need to be stabilised, to reduce the risk of significant losses prior to ingestion by the fish. Coating of solvent-spiked pellets with calcium alginate was shown to reduce leaching losses of water-soluble test items significantly. Alternatively, commercial feeding pellets can be coated with alginate or vegetable oil fortified with a radiolabelled test item also leading to sufficiently stabilised test diets. Experimental conditions, such as the water temperature, may have a significant effect on the leaching behaviour of the test items.

CONCLUSIONS

A detailed description of different spiking and coating procedures for the preparation of experimental diets suitable for fish metabolism studies is provided.

Perceptions of critical care outreach within a network

AIM

The purpose of this study was to establish healthcare professionals' perceptions of critical care outreach.

METHOD

A multi-site survey approach was used to collect qualitative data.

RESULTS

Most respondents felt that outreach assisted with patient care by enabling the admission and smooth discharge to and from the critical care units and providing useful education and training that changed practice. Respondents also thought that the audits undertaken by the outreach teams benefited patient care.

CONCLUSION

Overall, outreach was considered by healthcare professionals to enhance patient care and improve practice.

Dynamics of core-shell particles in concentrated suspensions

The dynamics of soft colloidal particles in a concentrated suspension was studied by two color dynamic light scattering. The short-time diffusion coefficient, D(s)(q), revealed a weak slowing down around the peak of S(q) in contrast to the much stronger dependence observed in hard sphere systems, and the absence of any slowing down in ultrasoft diblock micelles. The low-q limit of the diffusion coefficient, D(s)(q=0), reflecting the cooperative nature of the dynamics was found to decrease from its dilute limit value in contrast to the weak increase observed in hard sphere systems. The behavior of D(s)(q) reflects distinct polymer-layer-induced hydrodynamic effects present in concentrated suspensions of core-shell particles.

Necrotizing enterocolitis after gastroschisis repair: a preventable complication?

BACKGROUND

Necrotizing enterocolitis (NEC) has been documented in up to 20% of infants after repair of gastroschisis and is responsible for significant morbidity. NEC is reported to occur up to 10 times more in preterm infants receiving standard formula compared with those who have been fed exclusively with breast milk. Does breast milk confer a similar protection against NEC in infants who have undergone surgery for gastroschisis?

METHODS

All newborns with gastroschisis delivered between 1990 and 1996 and treated in a single neonatal unit were analyzed retrospectively. Clinical data, details of feeding regimens, and episodes of definite NEC were recorded.

RESULTS

Of 60 infants with gastroschisis, 6 (10%) died but none had evidence of NEC. Of the remaining 54 infants, clinical and radiological signs of NEC developed in 8 (15%). All recovered with medical treatment including the three patients with recurrent episodes. NEC developed in none of the 12 babies exclusively fed with expressed breast milk (EBM) in contrast to 1 (5%) of the 19 who received both EBM and formula, and 7 (30%) of the 23 who were fed solely on formula. There was no significant difference in gestation, incidence of primary versus silo closure, or incidence of intestinal atresia/stenosis in those with NEC (n=8) compared with those without (n=46), but birth weight in the NEC group was lower. NEC was less likely to develop in infants who received EBM than those who were exclusively formula fed (P < .02).

CONCLUSION

After gastroschisis repair, feeding with maternal expressed breast milk may help to protect the infant from developing NEC.

Use of muscle flap to cover infections of the carotid artery after carotid endarterectomy

Wound infection after carotid endarterectomy is an extremely uncommon complication. This complication occurred in two of our patients in a series of 170 consecutive carotid endarterectomies over the last 3 years. There has been an increased use of prosthetic patch grafts to close carotid endarterectomy sites. However, the presence of infection in the setting of prosthetic graft material poses difficulties in management and may lead to life-threatening complications. Recent strategies for the management of wound infections (in cases where the artery/graft interface is intact) include the use of appropriate antibiotics, repeated wound debridement, and covering the tissue defect or the perigraft area with well-vascularized muscle flap. In this case report the use of sternocleidomastoid muscle flap as a coverage for the infected area is described. The use of sternocleidomastoid muscle flap helped control the infective process and secured the viability of the patched carotid arteries.

CP-154,526: a potent and selective nonpeptide antagonist of corticotropin releasing factor receptors

Here we describe the properties of CP-154,526, a potent and selective nonpeptide antagonist of corticotropin (ACTH) releasing factor (CRF) receptors. CP-154,526 binds with high affinity to CRF receptors (Ki < 10 nM) and blocks CRF-stimulated adenylate cyclase activity in membranes prepared from rat cortex and pituitary. Systemically administered CP-154,526 antagonizes the stimulatory effects of exogenous CRF on plasma ACTH, locus coeruleus neuronal firing and startle response amplitude. Potential anxiolytic activity of CP-154,526 was revealed in a fearpotentiated startle paradigm. These data are presented in the context of clinical findings, which suggest that CRF is hypersecreted in certain pathological states. We propose that a CRF antagonist such as CP-154,526 could affirm the role of CRF in certain psychiatric diseases and may be of significant value in the treatment of these disorders.

Finger injuries from infant mittens; a continuing but preventable hazard

During the last 4 years, three infants have presented with finger-tip injuries secondary to entrapment in woollen/synthetic mittens. The accident happened at home in one case but the other two occurred in different neonatal units. Spontaneous amputation of the terminal phalanx of the index finger occurred in two patients but in the other there was complete healing. This problem may be avoided by restricting the use of mittens, by changing their design, and by a greater awareness of this hazard.