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Biomedical subjects

J Codd

Publications and source records attributed to J Codd.

11 recordsLinked to original sources
PubMed2002

Distribution of vascular endothelial growth factor (VEGF) in prostate disease.

Vascular endothelial growth factor (VEGF) is a heparin-binding polypeptide growth factor. It is a potent mitogen for endothelial cells. Immunohistochemical localisation of VEGF was performed on 25 moderate to poorly differentiated stage T4 M+ prostate cancer specimens and 30 benign prostatic hyperplasia (BPH) specimens. A positive result was indicated by area staining >25% and +2 or +3 staining intensity. Positive epithelial staining was observed in 50% of BPH specimens and 56% of cancer specimens, while positive stromal staining was observed in 73% of BPH specimens and 30% of cancer specimens. This may reflect an active role for stromal VEGF in the pathological process of BPH.

Endothelial Growth Factors↗
PubMed2000

Languages, scripts, and the environment: factors in developing concepts of print.

Preschool children bilingual in English and Hebrew were investigated for their understanding of concepts of print by means of two tasks. In the first, children had to understand that a printed word did not change its meaning if it moved to a new location. In the second, children had to make judgments about word length and ignore the size of the named objects. Previous research had shown bilingual French-English and Chinese-English children to excel in the first task, but only older Chinese-English bilinguals had an advantage in the second. The present study extended those results by investigating the effect of writing system in more detail. The study also examined the effect of the language of the environment by conducting parallel studies in environments in which either English or Hebrew was the community language. The results show that the bilingual children in both settings were more advanced than the monolinguals in both tasks and in both settings.

Child, Preschool↗
PubMed2000

Representing quantity beyond whole numbers: some, none, and part.

Previous research has demonstrated how children develop the ability to use notational representations to indicate simple quantities. These studies have shown a developmental shift from the use of idiosyncratic, to analogical, to conventional, numerical notations. The present paper extends these findings by reporting the results from a study in which children from 3 to 7 years old were asked to write a representation to indicate a quantity presented in a game-like scenario. Three kinds of quantities were included: whole numbers, zeros, and fractions. The children's notations were shown to them shortly after they were produced and then again two weeks later to see if children could interpret them. The results showed the familiar developmental pattern towards increased use of conventional notations for all quantities. The ability to read the notations was greatest for conventional numbers where performance was at ceiling, lower for analogue representations, and very poor for idiosyncratic global recordings. Children's choice of a notational format was influenced almost entirely by their age and not by the quantity being represented. Children were able to solve the zero problems almost as well as they could the whole numbers, but their understanding and use of representations for fractions was very limited.

Child↗
PubMed1997

Epstein-Barr virus latent membrane protein does not inhibit differentiation and induces tumorigenicity of human epithelial cells.

Latent membrane protein (LMP) is a latent Epstein-Barr virus (EBV) protein expressed in the EBV associated malignancy, nasopharyngeal carcinoma (NPC). Properties ascribed to this protein include inhibition of epithelial cell differentiation and deregulation of epithelial cellular gene expression, and are believed to contribute to the development of NPC. Studies to evaluate the oncogenic potential of LMP in epithelial cells have not been conclusive. We carried out studies to determine the tumorigenic activity of LMP in two human epithelial cell lines, SCC12F and HaCaT; while SCC12F LMP transfectants were non-tumorigenic in severe combined immunodeficient mice, HaCaT LMP transfectants were strongly oncogenic. The tumours produced were well differentiated, keratinising squamous cell carcinomas suggesting that LMP does not inhibit epithelial cell differentiation which conflicts with a previous report by Dawson et al. (1990). To resolve this discrepancy we examined the ability of HaCaT and SCC12F LMP transfectants to differentiate in a suspension culture assay. Both lines were able to differentiate to a similar extent as parental lines and control transfectants. Our results indicate that LMP is strongly oncogenic in human epithelial cells but that inhibition of differentiation is not necessarily a mechanism by which LMP contributes to the pathogenesis of NPC.

Animals↗
PubMed1989

Onset of expression of peanut lectin-binding glycoproteins is correlated with stratification of keratinocytes during human epidermal development in vivo and in vitro.

During gestation the epidermis develops from a single layer of ectoderm into a layer of keratinocytes overlaid by a layer of periderm; this is followed by a progressive increase in the number of layers of keratinocytes, until finally the distinct granular and cornified layers characteristic of mature epidermis are formed. As part of our investigation into the function of the peanut lectin-binding glycoproteins of cultured human keratinocytes, we have examined their expression at different stages of human epidermal development. We found that the onset of expression of the glycoproteins coincided with the transition from a two- to a three-layered epidermis, both in vivo and in organ culture. In adult epidermis, the patterns of binding of peanut lectin and Limax flavus lectin are complementary, with peanut binding more strongly to suprabasal keratinocytes and Limax flavus lectin binding more strongly to cells in the basal layer. We found that the complementary pattern of binding of the two lectins was established at, or shortly after, the onset of stratification and retained throughout development. In contrast, expression by keratinocytes of involucrin, a protein precursor of the cornified envelope, occurred after stratification had begun. Finally, we identified the peanut lectin-binding glycoproteins of adult epidermis by immunoblotting with an antiserum raised against the glycoproteins of cultured neonatal keratinocytes. In conclusion, expression of the peanut lectin-binding glycoproteins is an early event in epidermal development, and this would be consistent with a role for the glycoproteins in stratification.

Embryonic and Fetal Development↗
PubMed1988

The morphology of ciliogenesis in the developing fetal human respiratory epithelium.

Segmental imaging studies of the respiratory epithelium from human embryos and fetuses of normal karyotype have demonstrated that ciliogenesis and ciliation of the respiratory epithelium starts at 7 weeks of gestation. Ciliated cell differentiation follows a pre-determined pattern of distribution. It starts exclusively in the upper segment of the membranous trachea and spreads distally. Ciliation of the carinal angle takes place at 8 weeks of gestation. Three patterns of basal body formation were identified. The various morphological features encountered are described and compared with those observed in cases of Immotile Cilia Syndrome and other pathological conditions. Ciliation of the respiratory epithelium in the cartilaginous trachea does not take place until after the 12th week of gestation. The morphological findings identified in our case material are in agreement with those observed in the developing respiratory epithelium of other higher mammals.

Bronchi↗
PubMed1981

Maternal antibody and respiratory syncytial virus infection in infancy.

One hundred newborn infants were studied prospectively for 1 year for evidence of infection with respiratory syncytial virus (RSV). The indirect membrane fluorescence technique was used to determine specific antibody in sera. Infection was shown in 29 cases. In 31 infants exposed to an RSV epidemic season, there was no evidence of infection. Maternal antenatal sera were also tested, and wide range of IgG antibody to RSV was found. Mean titre of maternal IgG antibody to RSV was significantly higher (P less than 0.001) in those mothers whose babies remained uninfected than in those whose babies had proved RSV infection before 6 months of age. Babies born to mothers with high levels of IgG antibody to respiratory syncytial virus were protected against infection with this virus during the first months of life when the risk of severe disease was greatest.

Adult↗
PubMed1979

Revascularization of the right coronary artery.

This study was undertaken to evaluate revascularization of the right coronary artery with regard to factors that enter into the decision to graft less significant lesions, such as graft flow, graft patency and progression of proximal disease. The results of grafting the right coronary artery were studied in 23 patients with lesions reducing luminal diameter by less than 50 percent (Group 1), 35 patients with luminal narrowing of 50 to 70 percent (Group 2) and 112 patients with greater than 70 percent luminal narrowing (Group 3). At operation there was no significant difference in saphenous vein graft flows among the three groups. Postoperatively the mean follow-up period was 20, 27 and 26 months, respectively. Graft patency was not significantly different among the three groups. Progression of the proximal lesion was studied and compared with that in 71 ungrafted right coronary arteries, 60 with less than 50 percent stenosis and 11 with more than 50 percent stenosis. Among vessels with less than 50 percent narrowing, the proximal lesion showed progression in 26 percent of the ungrafted vessels and in 83 percent of the grafted vessels (P less than 0.005); progression to total occlusion occurred in 3 percent of the former and in 28 percent of the latter (P less than 0.005). Progression to total occlusion was more frequently associated with a patent than with an occluded graft (P less than 0.05). The occurrence of significant progression in ungrafted vessels and the lack of effect on graft patency of the severity of the proximal disease suggest that revascularization of less significant lesions may be of value. However, the resultant increase in progression of proximal disease makes the patient dependent on the long-term patency of the vein graft.

Cardiac Catheterization↗