Biomedical subjects

E Hirst

Publications and source records attributed to E Hirst.

At least 19 recordsLinked to original sources

PubMed2004

Postnatal depression across countries and cultures: a qualitative study.

BACKGROUND: Postnatal depression seems to be a universal condition with similar rates in different countries. However, anthropologists question the cross-cultural equivalence of depression, particularly at a life stage so influenced by cultural factors. AIMS: To develop a qualitative method to explore whether postnatal depression is universally recognised, attributed and described and to enquire into people's perceptions of remedies and services for morbid states of unhappiness within the context of local services. METHOD: The study took place in 15 centres in 11 countries and drew on three groups of informants: focus groups with new mothers, interviews with fathers and grandmothers, and interviews with health professionals. Textual analysis of these three groups was conducted separately in each centre and emergent themes compared across centres. RESULTS: All centres described morbid unhappiness after childbirth comparable to postnatal depression but not all saw this as an illness remediable by health interventions. CONCLUSIONS: Although the findings of this study support the universality of a morbid state of unhappiness following childbirth, they also support concerns about the cross-cultural equivalence of postnatal depression as an illness requiring the intervention of health professionals; this has implications for future research.

Adult↗

PubMed2001

Regulated endocytic routing modulates wingless signaling in Drosophila embryos.

Embryos have evolved various strategies to confine the action of secreted signals. Using an HRP-Wingless fusion protein to track the fate of endocytosed Wingless, we show that degradation by targeting to lysosomes is one such strategy. Wingless protein is specifically degraded at the posterior of each stripe of wingless transcription, even under conditions of overexpression. If lysosomal degradation is compromised genetically or chemically, excess Wingless accumulates and ectopic signaling ensues. In the wild-type, Wingless degradation is slower at the anterior than at the posterior. This follows in part from the segmental activation of signaling by the epidermal growth factor receptor, which accelerates Wingless degradation at the posterior, thus leading to asymmetrical Wingless signaling along the anterior-posterior axis.

Animals↗

PubMed2000

Plasmodium chabaudi-infected erythrocytes adhere to CD36 and bind to microvascular endothelial cells in an organ-specific way.

Adherence of erythrocytes infected with Plasmodium falciparum to microvascular endothelial cells (sequestration) is considered to play an important role in parasite virulence and pathogenesis. However, the real importance of sequestration for infection and disease has never been fully assessed. The absence of an appropriate in vivo model for sequestration has been a major barrier. We have examined the rodent malaria parasite Plasmodium chabaudi chabaudi AS in mice as a potential model. Erythrocytes infected with this parasite adhere in vitro to purified CD36, a critical endothelium receptor for binding P. falciparum-infected erythrocytes. P. c. chabaudi-infected erythrocytes adhere in vitro to endothelial cells in a gamma interferon-dependent manner, suggesting the involvement of additional adhesion molecules in the binding process, as is also the case with P. falciparum-infected cells. Furthermore, plasma or sera from infected and hyperimmune mice, respectively, have the ability to block binding of infected erythrocytes to endothelial cells. In vivo, erythrocytes containing mature P. c. chabaudi parasites are sequestered from the peripheral circulation. Sequestration is organ specific, occurring primarily in the liver, although intimate contact between infected erythrocytes and endothelial cells is also observed in the spleen and brain. The results are discussed in the context of the use of this model to study (i) the relationship between endothelial cell activation and the level of sequestration and (ii) the primary function of sequestration in malaria infection.

Animals↗

PubMed1998

Specialised service to children with specific language impairment in mainstream schools.

The following report describes a three year project to develop, implement and evaluate a specialised speech and language therapy (SLT) service to children with specific language impairment (SLI) who attend mainstream schools and nurseries. The report describes how the service was set up and the package of care offered. A range of evaluation measures was designed and implemented and the results of these are discussed. The service aimed to enable key-workers to support children with SLI effectively within the context of the school environment. The results suggest that the package of care offered provided an effective and high quality service as judged by the parents, schools and therapists.

Child↗

PubMed1996

Establishment and characterization of conditionally immortalized cells from the mouse urogenital ridge.

Cell cultures from the urogenital ridge have been established to facilitate the study of the regulation and downstream interactions of Sry in mammalian sex determination. Cells have been explanted from transgenic mice carrying a temperature sensitive SV40 large T-antigen, and established in ongoing cultures. Analysis of the cells in these cultures at the electron microscope level reveals multiple cell types that compare to the cell types found in vivo during this period of development. Primordial germ cells, that are simultaneously explanted in the course of these experiments, also survive in culture. The explants undergo a morphogenetic organization into branching cord-like structures when cells are trypsinized and plated in extracellular matrix (Matrigel). We analyzed the expression of a number of molecular markers of the fetal gonad during monolayer culture, during in vitro morphogenesis in Matrigel, and in clonal lines derived from the complex explants. This analysis included Sry which is found to be expressed in some cultures from XY urogenital ridges that have been maintained for as long as 8 months.

Alleles↗

PubMed1991

Clustering of dendrites in the cerebral cortex begins in the embryonic cortical plate.

In this study, we have asked what organizational features can be detected in the embryonic rat cerebral cortex. We have found evidence using light microscopy, and scanning and transmission electron microscopy, that soon after the first cortical neurons join the cortical plate, their apical dendrites form clusters. These clusters are characterized by the close apposition of dendritic membranes, and by intermediate-type junctions. Clustering occurs within 24 h of cortical plate formation, at a time when the cortical plate is about six cell diameters thick, and before the cortex has any afferent input or the cortical plate any synapses. Thus the clustering of apical dendrites in the cortical plate appears to be a very early organizational feature in the development of the cerebral cortex.

Animals↗

PubMed1988

Perturbations of the topography of the tegument of adult Schistosoma mansoni. A scanning electron microscope study.

1. Adult Schistosoma mansoni show a proclivity to release fragments of the tegumental surface membrane when they are incubated in various media, or after they are exposed to positively charged microspheres. Scanning electron microscopy was used to examine the extent and nature of the perturbations induced by the two treatments used to prepare tegumental membranes. 2. Incubation of the parasites in a phosphate-buffered medium resulted in extensive blebbing and release of vesicles from the tegument. 3. Attachment of positively charged microspheres followed by their release yielded tegument membrane fragments of a different morphology. 4. The nature and implications of these perturbations to membrane processes occurring at the tegument of schistosomes are discussed.

Animals↗

PubMed1984

Fibre order in the normal Xenopus optic tract, near the chiasma.

In juvenile Xenopus retinotopic fibre order in the optic tract near the chiasma was investigated by labelling small groups of optic fibres from peripheral retina with HRP. This selective fibre labelling with HRP was combined with autoradiography following administration of tritiated thymidine to the eye, so that the HRP-labelled fibres could be located within the borders of the optic tract. Fibres arising from the periphery of all four retinal quadrants were superficially located in the optic tract near the chiasma, with dorsal retinal fibres showing the greatest tendency to travel deep in the diencephalon. Retinal lesions closer to the optic nerve head labelled fibres which ran deeper in the optic tract. Near the chiasma, fibres from ventral retina tended to group rostrally while fibres from dorsal retina tended to group caudally. However, no obvious localization of fibres arising in temporal or nasal retina was seen in the lower optic tract.

Age Factors↗

PubMed1981