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Biomedical subjects

M Giles

Publications and source records attributed to M Giles.

At least 55 records · Page 3Linked to original sources
PubMed1993

Expression of a suppressive p15E-related epitope in colorectal and gastric cancer.

mRNA for the suppressive epitope of p15E was found to be present in 24 of 30 samples of human colorectal cancer and in all four specimens of gastric cancer. mRNA for p15E was seldom seen in nonmalignant colonic or gastric mucosa but, when present, was associated with inflammatory or pre-malignant conditions of the digestive tract. Synthetic peptides derived from the conserved p15E sequence were found to suppress some aspects of the immune response implicated in anti-tumour activity. These data suggest that a p15E-related material with immunomodulatory properties is elaborated within human tumours, either by the tumour itself or as a normal component of the endogenous anti-tumour reaction.

Base Sequence↗
PubMed1993

Ambulatory blood pressure and left ventricular mass in cyclosporin- and non-cyclosporin-treated renal transplant recipients.

OBJECTIVES: First, to determine the relationship between left ventricular mass (LVM) and clinic and 24-h ambulatory blood pressure parameters in normotensive renal transplant recipients. Secondly, to assess the influence of immunosuppression protocol on diurnal blood pressure and target-organ response. DESIGN: Measurement of supine clinic blood pressure, non-invasive 24-h ambulatory blood pressure and echocardiographically determined LVM. PATIENTS: Twenty-eight stable, normotensive renal transplant recipients taking no antihypertensive therapy (16 cyclosporin-treated and 12 non-cyclosporin-treated). SETTING: Community-based ambulatory patients reviewed in tertiary referral centre. MAIN OUTCOME MEASURES: Clinic blood pressure, mean 24-h, daytime and night-time ambulatory blood pressure and LVM. RESULTS: Mean 24-h blood pressure exceeded that recorded in the clinic. Twenty-five per cent of patients had left ventricular hypertrophy despite the absence of hypertension, and this was more common in cyclosporin-treated than in non-cyclosporin-treated patients. Mean daytime systolic blood pressure was the best predictor of LVM, being superior to clinic blood pressure and any diastolic blood pressure parameter. An attenuated nocturnal blood pressure fall ('non-dipper' pattern) was common, especially in those patients treated with cyclosporin, and was associated with higher LVM. CONCLUSION: In normotensive renal transplant recipients, a group at risk of cardiovascular disease, 24-h ambulatory blood pressure is closely related to the development of left ventricular hypertrophy, and may prove useful in optimizing treatment strategies to reduce cardiovascular morbidity.

Blood Pressure↗
PubMed1993

Screening for HIV and hepatitis B virus in Los Angeles County prenatal clinics: a demonstration project.

A project designed to pilot voluntary screening for HIV antibody and hepatitis B virus antigen (HBsAg) in women using Los Angeles County Department of Health Services prenatal clinics is described. The purpose of the study was to demonstrate that HIV testing could be integrated into an existing prenatal health care system with minimal disruption. In an 8-month period, 9,069 women entered the project; 76% accepted HIV antibody testing. The rate of HIV antibody seropositivity was 144 per 100,000 (10 per 6,943), and the rate of HBsAg seropositivity was 253 per 100,000 (23 per 9,103). No difference in test acceptance rates was found using a sign-off versus a sign-on HIV antibody consent form although potential confounders were not controlled. Only five of the eight HIV antibody-positive women (63%) and eight of the 20 HBsAg-positive women (40%) who were interviewed reported behaviors considered high risk for HIV or HBsAg infection.

Adult↗
PubMed1992

Impairment of the activity of the hepatic microsomal glucose-6-phosphatase system in three preterm infants.

Three preterm infants born at 26-30 weeks' gestation who died between 103 and 266 days after birth were found to have elevated hepatic glycogen levels. Kinetic analysis of the hepatic microsomal glucose-6-phosphatase system demonstrated that one infant had abnormally low levels of activity of the glucose-6-phosphatase enzyme (partial type 1a glycogen storage disease) and two had deficiencies of T2, a microsomal phosphate/pyrophosphate transport protein (type 1c glycogen storage disease). In all three cases glycogen storage disease was not suspected prior to death even though both hypo- and hyperglycaemic episodes were recorded in the first 15 days after birth indicating that they had somewhat disordered blood glucose regulation. In the infant with low glucose-6-phosphatase enzyme activity, abnormal development of the glucose-6-phosphatase enzyme cannot be ruled out. This is the first description of abnormalities in the glucose-6-phosphatase system in preterm infants.

Biopsy↗
PubMed1991

Self-differentiation of human fetal lung organ culture: the role of prostaglandins PGE2 and PGF2 alpha.

Addition of PGE2, but not PGF2 alpha, to fetal lung organ cultures accelerates the process of self-differentiation with increased dilatation of terminal airsacs and differentiation of the epithelial lining. Indomethacin reduces the endogenous production by organ cultures of PGE2, PGF2 alpha, 13,14-dihydro-15-keto-PGE2, and 13,14-dihydro-15-keto-PGF2 alpha and retards the process of self-differentiation. Prolonged exposure of cultures to indomethacin results in cell necrosis. Indomethacin inhibition of self-differentiation can be reversed and accelerated by the addition of PGE2. Addition of PGF2 alpha in the presence of indomethacin prevents indomethacin-associated cell necrosis but does not accelerate dilatation or differentiation beyond that of cultures in sera-free media without additions. We propose that the endogenous production of PGE2 is a key process in the mechanism of self-differentiation of human fetal lung in organ culture.

Cell Differentiation↗
PubMed1991

Prevalence and natural history of otitis media with perforation in Maori school children.

New Zealand Maoris are one of five ethnic groups in developed countries known to have a high rate of ear disease, including perforation of the eardrum (CSOM). It is a strongly held belief by otolaryngologists whose practice dates back to the 1960's that the prevalence of CSOM in Maori children is gradually falling. Despite the obvious practical implications this change has not yet been documented. The aim of the study was to compare the prevalence of CSOM in two surveys conducted in 1978 and 1987 of children living in a North Island Maori community. A second aim was to examine the natural history of CSOM in these children. The raw data from the 1978 study were reviewed. Of 134 children aged 4-13, 12 had CSOM. In 1987 the same age group yielded 12 children out of 250 with CSOM. The prevalence of CSOM fell from 9 per cent to 4 per cent. The incidence of new perforations in 1987 was 1.3 per cent per child per year. It is concluded there has been a fall in the rate of CSOM, although otitis media remains a significant problem for these children. The probability of a perforation healing was influenced by whether or not the perforation had been observed before: at least 35 per cent of perforations seen for the first time healed, but none of the perforations seen on two occasions healed spontaneously. It was concluded that perforation of the eardrum can be managed conservatively at first.

Adolescent↗
PubMed1991

The prevalence of hearing impairment amongst Maori schoolchildren.

A survey of hearing amongst a population of Maori schoolchildren in the eastern North Island of New Zealand has demonstrated a high prevalence of hearing impairment. Out of 194 children undergoing audiometry an impairment of 20 dB or greater at 0.5, 1.2 and 4 kHz was found in the worse hearing ear in 29% and in the better hearing ear in 12%. Comparison with a similar survey done in the same valley in 1977 revealed an apparent reduction in the prevalence of hearing loss and the prevalence of otitis media. This improvement appears to be due to a reduced prevalence of otitis media. An unexpected finding was that at least 2% of the children had a bilateral sensorineural hearing impairment.

Adolescent↗
PubMed1990

The ontogeny of human hepatic microsomal glucose-6-phosphatase proteins.

We have studied 250 human liver biopsy samples to determine the ontogeny of the microsomal glucose-6-phosphatase (EC 3.1.3.9) system. Human hepatic glucose-6-phosphatase enzyme activity develops at 11 weeks' gestation and slowly increases to approximately 10% of adult activity at term. In the first week after birth, activity rises to adult values. Increases in enzyme activity coincide with increasing concentrations of the glucose-6-phosphatase enzyme protein. The phosphate/pyrophosphate transport protein (T2) of the human hepatic glucose-6-phosphatase complex develops at a different rate from that of the enzyme. Our study shows that the development of rat and human glucose-6-phosphatase activities are completely different. We conclude that deficiencies of the proteins in the microsomal glucose-6-phosphatase complex can be diagnosed with much more certainty perinatally than prenatally.

Adult↗
PubMed1989

Otitis media and hearing loss in the children of the Ruatoki valley: a continuing public health problem.

A longitudinal survey of ear disease using repeated otomicroscopy has demonstrated cases of persistent middle ear effusion, cholesteatoma and perforation in a group of 275 Maori children. The hearing of 194 of the children was assessed, and 25% of them were found to have a hearing loss. It is concluded a public health problem exists with these children. Improved detection and treatment of ear disease and hearing loss in this population is recommended.

Acoustic Impedance Tests↗
PubMed1989

Colour naming of violence-related words in Northern Ireland.

To investigate the hypothesis that people in Northern Ireland are using denial to cope with the impact of political violence, a specially designed version of the Stroop test was developed. English students living in Northern Ireland evidenced significantly greater interference on the Violent Stroop compared to either English students living in England or Northern Irish students living in Northern Ireland suggesting that while the Northern Irish natives had habituated to the violence the English students living in Northern Ireland had not yet done so.

Adult↗
PubMed1989

HIV seroprevalence in intravenous drug users: Los Angeles, California, 1986.

To estimate the seroprevalence and investigate risk behaviors for HIV (human immunodeficiency virus) infection in intravenous drug users in Los Angeles County, a stratified, random sample of 790 clients, enrolled in either methadone maintenance or detoxification programs, were studied. Thirteen study participants (1.8 per cent) were seropositive; of these, five were homosexual/bisexual males and three were female prostitutes. Ninety-five per cent of all participants reported sharing needles. Risk reduction education efforts must be expanded before the HIV antibody prevalence rate increases.

Female↗
PubMed1986

Clinical signs in the Wernicke-Korsakoff complex: a retrospective analysis of 131 cases diagnosed at necropsy.

A recent necropsy study has shown that 80% of patients with the Wernicke-Korsakoff syndrome were not diagnosed as such during life. Review of the clinical signs of these cases revealed that only 16% had the classical clinical triad and 19% had no documented clinical signs. The incidence of clinical signs in this and other retrospective pathological studies is very different from that of prospective clinical studies. This discrepancy may relate to "missed" clinical signs but the magnitude of the difference suggests that at least some cases of the Wernicke-Korsakoff syndrome may be the end result of repeated subclinical episodes of vitamin B1 deficiency. In order to make the diagnosis, clinicians must maintain a high index of suspicion in the "at risk" group of patients, particularly alcoholics. Investigations of thiamine status may be helpful and if the diagnosis is suspected, parenteral thiamine should be given.

Alcohol Amnestic Disorder↗
PubMed1985

Variability of androgen-related phenotypes in the Shionogi mammary carcinoma during growth, involution, recurrence, and progression to hormonal independence.

Several parameters of androgen action were measured in hormone-dependent Shionogi carcinoma cells during phases of growth, regression, and recurrence. In the parental C1 line under steady state conditions, dihydrotestosterone is localized exclusively in the nucleus while testosterone is confined almost entirely to the cytoplasm. After castration, the concentration of testosterone declines more rapidly than that of dihydrotestosterone. Spontaneous recurrent growth is not accompanied by significant elevation of the whole-tissue concentration of either androgen. Neither are changes observed in the concentration of cytoplasmic receptor or in the rate of uptake of androgens into the nucleus. However, relapse is associated with the appearance of a glucose-6-phosphate dehydrogenase double-enzyme phenotype and a loss of responsiveness to androgen withdrawal. The autonomous C3 variant line which is devoid of androgen-related markers is characterized by a deficiency of androgen retention by whole tissue and possibly a permeability defect of the plasma membrane. This variant tends to express a glucose-6-phosphate dehydrogenase double-enzyme phenotype. In contrast, the autonomous C4 variant line retains the ability to concentrate modest levels of testosterone in whole tissue and high levels of dihydrotestosterone in the nucleus. Although the number of nuclear binding sites is the same as that observed in the parental C1 line, the concentration of cytoplasmic receptor and the rate of nuclear uptake of androgens are relatively decreased. Expression of a glucose-6-phosphate dehydrogenase double-enzyme phenotype is less frequent than in the autonomous C3 variant line. The above results suggest that a recurrent tumor may contain hormone-sensitive cells which resume growth in an androgen-depleted environment. They also imply that progression from the androgen-dependent to the autonomous condition involves the selection and outgrowth of hormone-insensitive cells of variable phenotype.

Androgens↗
PubMed1981

Cerebral lupus erythematosus responding to plasmaphaeresis.

A 44-year-old nurse with a 12-year history of systemic lupus erythematosus developed a schizophrenia-like psychosis due to cerebral lupus. Prednisolone in doses up to 200 mg daily was ineffective. Levels of immune complexes by the Raji cell assay were greatly increased in serum and cerebrospinal fluid. Plasma exchange was performed on 4 occasions over 4 days. Three days later, there was a marked and sustained improvement in the mental state, the psychosis resolved and tests of psychological function and electroencephalographic abnormalities improved. There was a corresponding decrease in levels of immune complexes and in titres of anti-neuronal antibody. Five months later, several serological indices had risen to pre-plasmaphaeresis levels except for the level of immune complexes. The patient remained in clinical remission. This case provides further evidence that high levels of circulating immune complexes may be a determinant of cerebral lupus and that plasmaphaeresis may be of lasting benefit in this disease.

Adult↗