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Biomedical subjects

R Hicks

Publications and source records attributed to R Hicks.

At least 73 records · Page 4Linked to original sources
PubMed1990

Abnormal neuroendocrine responsivity to acute i.v. clomipramine challenge in depressed patients.

The neuroendocrine responsivity to an acute serotonergic challenge with low-dose i.v. clomipramine was studied in seven drug-free depressed patients and seven age-matched healthy control subjects. The depressed patients had higher baseline prolactin concentrations than the healthy subjects, and their prolactin response to clomipramine, assessed as either the percent of baseline or the log-transformed concentration, was significantly different (delayed and blunted peak response) compared to healthy controls. The growth hormone response was exaggerated in the depressed patients, and there were also trends toward blunting in their cortisol and adrenocorticotropic hormone responses. These results are consistent with previous findings of altered neuroendocrine responses to a variety of putative serotonin agonists in depressed patients.

Adrenocorticotropic Hormone↗
PubMed1990

Factors influencing the initiation of carious lesions in specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years.

An analysis of factors influencing the initiation of carious lesions on specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years is presented. Approximately 1000 children, resident in the County of South Glamorgan, Wales, were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. On both occasions, the children completed detailed questionnaires on dental health-related topics. Surfaces which were sound when the children were 11-12 years were identified and subsequently awarded a score of zero if they remained sound at 15-16 years or a score of one if they had developed carious lesions or had been filled. For each child, a mean mouth caries initiation score was computed for specific groups of surfaces, namely pit and fissure surfaces in posterior teeth, approximal surfaces in posterior teeth, buccal and lingual smooth surfaces of all teeth and approximal surfaces of anterior teeth. One-way analysis of variance and multiple regression techniques revealed that a number of factors had a significant influence on the initiation of caries. The factors and their level of significance varied between the surfaces. However, relatively little (less than 6 per cent) of the total variance in caries initiation score could be explained by the identified factors. Overall, more lesions developed in pit and fissure surfaces in posterior teeth than in the other surfaces included in the analyses.

Adolescent↗
PubMed1990

Factors influencing the caries experience of a group of children at the ages of 11-12 and 15-16 years: results from an ongoing epidemiological survey.

An analysis of factors influencing the caries experience of adolescents in South Wales is presented. Approximately 1000 children were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. In addition, on both occasions, the children completed detailed questionnaires on dental health-related topics. When aged 11-12 years, the observed mean DMFT, DMFS and DFS scores of the children were 4.0, 6.7 and 5.5 respectively. The corresponding scores at age 15-16 years were 6.5, 11.8 and 10.2. A preliminary analysis using conventional multiple regression techniques revealed that a number of factors had a significant influence on the caries experience of the children. The significance of the factors depended on the sex of the population subgroup, the age of the children and the particular caries index studied. However, at both ages the factors of most significance were the number of erupted teeth, total mean plaque score and the reported amount of money spent on sweets per week. A further evaluation using analysis of covariance with the number of erupted teeth and surfaces as the covariates confirmed the significant influence of the total mean plaque score and amount of money spent on sweets. In addition, both analyses indicated that toothbrushing frequency and social class had a significant influence on the caries experience of boys.

Analysis of Variance↗
PubMed1990

Epstein-Barr virus and other herpesvirus infections in Kawasaki syndrome.

Epstein-Barr virus (EBV), a possible cause of Kawasaki syndrome (KS), is not pathenogenically associated with KS in Hawaii. The prevalence of EBV capsid antibody in KS patients was found not to differ significantly from that in controls, and the antibody response in those infected with EBV was the same as that in other children similarly infected. No EBV was isolated from acute-phase patients. All patients with capsid antibody at the onset of KS also had Epstein-Barr nuclear antigen antibody: 36 patients developed antibody within 3 months after onset of KS; in 10, EBV infection could have been coincidental with the disease. Cytomegalovirus (CMV) was isolated from 9 patients with KS and 10 controls. A similar number of controls and patients had antibody to human herpesvirus 6 (HHV6); one patient seroconverted. None of the herpes viruses (EBV, CMV, HHV6, varicella-zoster virus, or herpes simplex virus) plays a unique or dominant role in the etiology or pathogenesis of KS in Hawaii.

Age Factors↗
PubMed1989

Characterization of toxicity involving haemorrhage and cardiovascular failure, caused by parenteral administration of a soluble polyacrylate in the rat.

Adverse effects, involving a combination of hypotension and widespread haemorrhages, as well as evidence of vascullar and other tissue dissociation, associated with various systemic malfunctions (cyanosis, cardiac arrhythmias, neuromuscular disorder and death) were observed in the rat, from parenteral administration of a high-molecular-weight soluble polymer, sodium polyacrylate (EN21). Experiments to elucidate the mechanism of this effect involved comparisons with a low-molecular-weight sodium polyacrylate (EN5), either drug being given to groups of 5-8 rats, male or female, in doses of 5-100 mg/kg i.v., i.p. or s.c., or up to 1000 mg/kg p.o. Effects were observed visually up to the death of the animals, and these plus survivors killed after 10 h were prosected for macroscopic and histopathological examination of internal organs. Characteristic EN21 effects were only observed in animals treated by the i.p. and i.v. routes, death occurring in 4-10 h or rapidly (1 h) after i.v. dosage. No such effects were observed from EN5 by any dose or route. There were no differences between effects in male and female animals. In rats anaesthetized with sodium pentobarbitone and cannulated for blood pressure recording (arterial and venous), no hypertensive effects were observed to explain haemorrhagic effects. Instead, i.v. and i.p. injections gave depressor effects, insidious in the latter case, with a precipitous fall only in the delayed terminal stage. Effects were accompanied by cardiac arrhythmias. Depressor effects were prevented by prior treatment of the animals with calcium chloride solution. These effects could not be evoked by EN5, nor by injection of methylcellulose solutions of equivalent high viscosity.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylic Resins↗
PubMed1989

The effects of intravenous clomipramine on neurohormones in normal subjects.

The neuroendocrine effects of iv administration of clomipramine (CMI), a serotonin reuptake inhibitor, were studied in normal subjects. Under double blind, placebo-controlled conditions, single 10- and 20-mg doses of CMI were administered. Ten milligrams of CMI led to significant increases in plasma PRL and cortisol concentrations; plasma ACTH increased slightly but not significantly. In contrast, plasma GH, melatonin, and norepinephrine concentrations did not increase. Plasma PRL, ACTH, and cortisol levels increased significantly after 20 mg CMI; again, there were no significant changes in plasma GH, melatonin, or norepinephrine concentrations. All subjects tolerated the 10-mg dose well, but the 20-mg dose caused nausea in three of six subjects. Desmethylclomipramine, a metabolite that inhibits reuptake of norepinephrine, was not detectable in plasma after either CMI dose. These results support the hypothesis that serotonin is involved in the regulation of PRL, cortisol, and ACTH in humans.

Adrenocorticotropic Hormone↗
PubMed1989

Outline features for chemical induction of delayed hypersensitivity.

The present paper attempts to set bounds for a qualitative and quantitative evaluation of immune-responses towards cellular mechanisms, as a tool for toxicological studies. It makes a plain distinction between the assessment of skin irritation and skin sensitization evoked by chemical haptens. Three well-known predictive methods to test delayed cutaneous hypersensitivity were used to elicit the reactions, either by epidermal patches or intradermal injections. The skin responses were scored according to the measurements of the oedema and erythema area. Hence, the specificity of the skin reaction was performed to verify the presence of possible cross-reaction amongst the chemical components used. These straightforward experimental features allow a more precise characterization of the cell-mediated reaction, nowadays, widely scattered amongst a few standardized technics or government reports. It may by concluded that the present work would help to separate an immunological response from other occurring phenomena.

Animals↗
PubMed1988

Pilot study of recombinant interferon alpha-2a for treatment of infants with bronchiolitis induced by respiratory syncytial virus.

Eleven children with bronchiolitis induced by respiratory syncytial virus received 10,000 to 70,000 U of recombinant interferon alpha-2a per kg of body weight per day. None developed signs of toxicity, and all but one developed an antiviral state following treatment. Interferon alpha-2a appears to be safe for infants with bronchiolitis. Its efficacy for the treatment of this condition remains to be determined.

Antibodies↗
PubMed1987

Effects of heparin and aminoguanidine on anaphylatoxin activity in the guinea-pig.

Heparin inhibited the bronchoconstrictor and pressor responses to histamine and anaphylatoxin. However, anaphylatoxin-induced hypotension, in contrast to that induced by histamine, was resistant to heparin inhibition. Aminoguanidine alone had no effect upon histamine or anaphylatoxin but it abolished the heparin-induced inhibition. It is therefore concluded that histamine mediates the bronchiolar and pressor but not the hypotensive effects of anaphylatoxin. Furthermore, anaphylatoxin causes the release of heparin to modulate the bronchiolar effects of extra-pulmonary histamine.

Amine Oxidase (Copper-Containing)↗
PubMed1987

Gait patterns in spastic hemiplegia in children and young adults.

Four homogeneous patterns of gait were defined in forty-six patients who had spastic hemiplegia secondary to cerebral palsy or other neurological disorders by analyzing kinematic data in the sagittal plane and electromyographic data. In Group I (twenty patients) the primary abnormality was a drop foot in the swing phase. The thirteen patients in Group II had a tight heel cord in the stance phase as well as a drop foot in the swing phase. The five patients in Group III also had more proximal involvement (that is, restricted motion of the knee) as well as an equinus deformity of the ankle. In Group IV, the eight patients had, in addition, restricted motion of the hip.

Adolescent↗