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C Lees

Publications and source records attributed to C Lees.

44 records · Page 3Linked to original sources

Effect of platelet-activating factor on secretion of mucous glycoprotein from chinchilla middle ear epithelial cells in vitro.

Platelet-activating factor (PAF) is a naturally occurring phospholipid that acts as a pleiotropic mediator and mediates cell-cell reactions under physiological and pathological conditions. Recently, it has been shown that PAF is a strong secretagogue of mucous glycoprotein in the airways, suggesting its role in mucous glycoprotein secretion and the pathogenesis of otitis media with effusion. In the current study, we examined the effect of PAF on mucous glycoprotein secretion in cultured chinchilla middle ear epithelial cells. PAF at 1 microM significantly stimulated mucous glycoprotein secretion from cultured chinchilla middle ear epithelial cells. This action was concentration-dependent, with secretions reaching near maximum when the cells were incubated with PAF at 100 microM. In a time-dependent study, PAF demonstrated an initial rapid stimulation of mucous glycoprotein secretion, followed by a gradual increase thereafter. A six-fold increase was seen in the first 2 h compared with controls. Cycloheximide, a protein synthesis inhibitor, demonstrated an inhibitory effect on PAF-stimulated mucous glycoprotein secretion in this study. These findings suggest that PAF plays an important role in the pathogenesis of otitis media with effusion by stimulating mucous glycoprotein secretion in vitro.

Animals↗

Materno-fetal immunoglobulin transfer and passive immunity during the first trimester of human pregnancy.

Passive transfer of immunity from the mother to the first trimester fetus is of particular interest because of the reported high incidence of serious fetal sequelae due to congenital infection. We have examined the relationship between maternal serum, coelomic fluid and amniotic fluid concentrations of immunoglobulin (Ig) and complement. Ig fractions G (IgG), A (IgA), and M (IgM) and complement factors 3 (C3) and 4 (C4) were measured in 34 normal pregnancies between 6 and 12 weeks of gestation. The concentrations of specific antibodies for Toxoplasma gondii, cytomegalovirus (CMV) and rubella were also measured on 21 matched samples from the same study group. IgG and IgA concentrations were detected in all coelomic fluid samples whereas IgG was only measurable in two amniotic fluid samples. IgG and IgA concentrations were respectively 28 and 128 times lower in coelomic fluid than in maternal serum and probably reflect fetal serum concentrations. Significant positive linear correlations were found between gestational age and the coelomic concentrations of IgG (P = 0.001) and IgA (P = 0.014). There was no obvious association between immunoglobulin concentrations in coelomic fluid and maternal serum suggesting increasing active transport across the placenta with advancing gestation. IgM, C3 and C4 were not detected in coelomic or amniotic fluid samples. Specific antibodies were found in 13 out of 63 samples of coelomic fluid and in 32 out of 63 samples of maternal serum. They were found in coelomic fluid only if they were present in maternal serum. These results suggest that maternal IgG and IgA are potentially available to the embryo as early as the 6th week of gestation. The presence in the coelomic fluid of the IgG fraction, both total and infectious agent-specific transferred via the placenta, indicates that they may provide limited protection against congenital infection in the first trimester.

Amniotic Fluid↗

Detection of sickle gene by coelocentesis in early pregnancy: a new approach to prenatal diagnosis of single gene disorders.

Coelomic fluid, placental tissue and maternal blood were collected at 7-10 weeks gestation from each of 58 women undergoing elective termination of pregnancy for psychological indications. In all samples, a 364 bp fragment of the human beta-globin gene spanning positions -23 to 341 was amplified. The restriction endonuclease Ddel was used to detect the sickle mutation which abolishes its restriction site. beta-Globin DNA was successfully amplified from all samples. In 53 cases a normal maternal beta-globin genotype was detected. In three out of five cases, where the maternal haemoglobin phenotype was HbAS, heterozygosity for the sickle mutation was demonstrated on analysis of coelomic fluid. In the remaining two cases a normal beta-globin genotype was observed. Three further coelomic fluid samples were found to be heterozygous for the sickle mutation. In these instances the maternal haemoglobin phenotype was normal, indicating paternal transmission of the sickle gene. The results of the present study have established that the diagnosis of sickle cell anaemia, and potentially other human single gene disorders, is feasible by coelocentesis.

Amniocentesis↗

Arrest of preterm labour and prolongation of gestation with glyceryl trinitrate, a nitric oxide donor.

13 women admitted consecutively in preterm labour were recruited to an observational study of the effect of glyceryl trinitrate (GTN) patches on uterine contractions and prolongation of pregnancy. All twenty episodes of preterm labour (at 23-33 weeks' gestation) responded. 1 patient delivered because of cervical incompetence despite cessation of uterine contractions. The mean prolongation of pregnancy was 34 days. 8 babies have been born so far, and are progressing well. GTN patches appear to be a safe, well-tolerated, and non-invasive method of suppressing uterine contractions in preterm labour.

Administration, Cutaneous↗

Poisson's ratio in skin.

Poisson's ratio of cow teat skin was measured uni- and biaxially and shown to be anisotropic and dependent on aspect ratio. At strains below 0.1 (where Cauchy and Hencky strain are indistinguishable) the Poisson's ratio of cow teat skin measured biaxially is very much greater than 1.0, whereas the Poisson's ratio of distending artery is between 0.5 and 0.3. Knitted fabric behaves similarly to cow teat skin in that it can give a negative Poisson's ratio at low strains. Skin is therefore probably to be considered mechanically as an open feltwork of fibres rather than some sort of continuum.

Animals↗

Sex-role perceptions in chemically dependent subjects: adults versus adolescents.

Contrary to expectations, a study of 81 adolescent drug and/or alcohol addicts produced results quite similar to those found among an adult addicted population (Griffin-Shelley, 1986). On the Bem Sex-Role Inventory (Bem, 1974), these young people rated themselves, in descending order, Undifferentiated (43.2%), Masculine (23.5%), Androgynous (18.5%), and Feminine (14.8%). Despite their exaggerated "macho" and "seductive" attitudes and behaviors, which resemble their adult counterparts, chemically dependent adolescents suffer similarly from low self-esteem and poor adjustment. Addictions appear to have already damaged these young people in areas of self-worth and sex-role perception.

Adolescent↗

Crisis at Christmas.

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Charities↗