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R Smith

Publications and source records attributed to R Smith.

At least 1,027 records · Page 57Linked to original sources
PubMed1989

Mouth stick design for the client with spinal cord injury.

This paper reviews literature on mouth sticks and presents information from a survey of occupational therapists specializing in the treatment of persons with spinal cord injuries. The review discusses the standards of mouth-stick design that have been established by dentists, but the survey suggests that occupational therapy practice is widely discrepant from these standards. The author suggests increased education for occupational therapists to provide knowledge of the key elements of oral safety, and increased collaboration between occupational therapists and dentists in mouth-stick design, fabrication, and training to assure quality care for all persons who require a mouth stick.

Equipment Design↗
PubMed1989

Sequence organization of the human int-2 gene and its expression in teratocarcinoma cells.

We report the genomic organization and DNA sequence of the human homologue of int-2, a proto-oncogene implicated in virally induced mammary tumours in the mouse, and expressed at specific sites and times during embryogenesis. Direct comparisons with the coding domains of mouse int-2 allowed us to delineate the intron-exon boundaries of the human gene. These boundaries were subsequently confirmed by ribonuclease protection analyses of the single 1.7 kilobase (kb) int-2 transcript detectable in the human teratocarcinoma cell line, Tera-2. The data suggest that human int-2 may also function in embryonic lineages but that its transcription may be less complex than in the mouse. The predicted human protein comprises 239 amino acids and is 89% homologous to its murine counterpart, except at the carboxy terminus. This divergence occurs distal to the region of int-2 that shows homology to other members of the FGF family of growth modulators and oncogenes.

Amino Acid Sequence↗
PubMed1989

Specificity of monoclonal antibodies in local passive immunization against Streptococcus mutans.

Local oral passive immunization in human subjects with a monoclonal antibody (MoAb) raised against the 185-kD antigen I/II from S. mutans significantly reduced or prevented oral colonization of an exogenous strain of the organism. In subjects sham-immunized with either saline or an unrelated MoAb, however, significantly greater proportions of S. mutans persisted for a longer duration than in those immunized with the specific anti-streptococcal MoAb. Recolonization of indigenous S. mutans after this organism was reduced to undetectable levels by an antimicrobial agent has also been completely prevented with specific MoAb. Indeed, S. mutans was not detected for a period of over 1 year, as compared with recolonization within 10-82 days in the control subjects. The specificity of MoAb in preventing colonization of the streptococci was studied with four MoAb. This revealed that: (1) the sub-class of antibody is not an essential factor, as both MoAb Guy's 1 and 13 prevented colonization, although Guy's 1 is an IgG2a and Guy's 13 is an IgG1 class of antibody; (2) serotype specificity is important, as MoAb Guy's 9, which only recognizes S. sobrinus (serotypes d and g), does not prevent colonisation by S. mutans (serotype c); (3) neither protein nor carbohydrate nature of the putative adhesin was a determining factor, because MoAb Guy's 1 recognizes a carbohydrate and Guy's 13 a protein determinant and both MoAb prevented adherence of S. mutans; and (4) epitope specificity appears to be the most important factor in preventing adherence of S. mutans, as MoAb Guy's 11 and 13 share the same serotype specificity and both recognize a protein determinant, yet only Guy's 13 prevents colonisation. The long duration of protection from re-colonization by indigenous S. mutans, lasting about 1 year after application of the specific MoAb was stopped, cannot be accounted for by functional MoAb remaining on the teeth. We suggest that initially the MoAb prevents colonization by S. mutans and that the ecological niche vacated by this streptococcus is filled by other organisms from the oral flora, thereby discouraging re-colonization by S. mutans.

Adult↗
PubMed1989

Macrophage function in mammary glands of Brucella abortus-infected cows and cows that resisted infection after inoculation of Brucella abortus.

Nonvaccinated pregnant cows were segregated retrospectively into 2 groups following inoculation with Brucella abortus strain 2308. One group resisted infection (resistant cows) and the other group developed active infections (susceptible cows) and subsequently aborted. Mammary gland macrophages collected from the 2 groups of cows were compared, using in vitro functional assays. In a chemiluminescence assay, mammary gland macrophages from resistant cows produced significantly (P = 0.014) higher oxidative burst activity than did macrophages from susceptible cows. Macrophages from resistant cows had significantly (P = 0.038) greater bacteriostatic activity against B abortus than did macrophages from susceptible cows. Differences in lysosomal enzymatic activity or Fc receptor expression were not observed for macrophages from the 2 groups of cows. Differences in macrophage function may be one factor responsible for natural resistance to Brucella infection in cattle.

Abortion, Veterinary↗
PubMed1989

Restriction of placental growth in sheep enhances placental metabolism of fetal beta-endorphin-like immunoreactivity.

The opioid polypeptide beta-endorphin is present in fetal blood but it is not clear whether its source is the fetus or the placenta. We therefore measured beta-endorphin in extracts of fetal femoral arterial and umbilical venous blood plasma in sheep by radioimmunoassay to determine whether the fetus or the placenta is the major source of beta-endorphin in the fetal circulation. Chromatographic analysis of extracts of fetal arterial plasma showed that beta-lipotropin and other precursors of beta-endorphin made only a minor contribution to the immunoreactivity detected. Concentrations of immunoreactive beta-endorphin were higher in the femoral artery than in the umbilical vein in fetal sheep between 113 and 128 days of pregnancy. Therefore the placenta removes beta-endorphin or a closely related polypeptide of fetal origin from the umbilical circulation in sheep at this stage of gestation. Acute hypoxaemia and hypoglycaemia increase the concentrations of immunoassayable beta-endorphin in blood plasma of adult and fetal sheep, but little is known about the effects of chronic hypoxaemia or hypoglycaemia on the circulating levels of beta-endorphin and related polypeptides in the fetus. Therefore we also measured immunoreactive beta-endorphin in blood plasma from fetal sheep in which growth retardation in association with restricted placental growth was produced by removal of endometrial caruncles before mating. Intra-uterine growth retardation was accompanied by chronic hypoglycaemia and chronic hypoxaemia in the fetuses. This was not associated with higher concentrations of beta-endorphin-like immunoreactivity in fetal arterial or umbilical venous plasma, but was accompanied by significantly increased placental extraction of fetal immunoreactive beta-endorphin from the umbilical circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Immunogenicity of a low dose recombinant DNA hepatitis B vaccine in healthy adults in Singapore.

The immunogenicity and safety of a standard dose of 10 micrograms of a yeast derived recombinant DNA hepatitis B vaccine (B-Hepavac II) was compared with that of a reduced dose of 5 micrograms in 84 healthy adult volunteers with no previous exposure to hepatitis B. Each subject received either a 10 micrograms or 5 micrograms dose of vaccine intramuscularly at 0, 1 and 6 months. One month after the second injection of vaccine the seroconversion rate in the two groups were 85 and 86 percent respectively. Two months after the third injection 100 percent of participants had sero-converted; 95 percent of the 10 micrograms group and 91 percent of the 5 micrograms group had titres of anti-HBs greater than 10 IU/L. The geometric mean titres (GMT) of anti-HBs levels at 2, 6, 8, and 12 months were 34, 61, 811 and 188 IU/L in the 10 micrograms group and 26, 45, 836 and 304 IU/L in the 5 micrograms group respectively. Adverse effects were mild and transient. The vaccine was safe and immunogenic in the doses given. The reduced dose of 5 micrograms was as effective as the standard 10 micrograms dose.

Adolescent↗
PubMed1988

Mineralocorticoid action: target tissue specificity is enzyme, not receptor, mediated.

Mineralocorticoid receptors, both when in tissue extracts and when recombinant-derived, have equal affinity for the physiological mineralocorticoid aldosterone and for the glucocorticoids cortisol and corticosterone, which circulate at much higher concentrations than aldosterone. Such receptors are found in physiological mineralocorticoid target tissues (kidney, parotid, and colon) and in nontarget tissues such as hippocampus and heart. In mineralocorticoid target tissues the receptors are selective for aldosterone in vivo because of the presence of the enzyme 11 beta-hydroxy-steroid dehydrogenase, which converts cortisol and corticosterone, but not aldosterone, to their 11-keto analogs. These analogs cannot bind to mineralocorticoid receptors.

Adrenalectomy↗
PubMed1988

Differential processing of corticotrophin-releasing hormone by the human placenta and hypothalamus.

The molecular forms of corticotrophin-releasing hormone (CRH) in human placentae and hypothalami were investigated by gel permeation chromatography of water extracts. Hypothalamic extracts produced one peak of immunoreactivity which coeluted with human CRH at Kd = 0.53. Placental extracts, however, had in addition to that peak, two other peaks eluting earlier at the void and at Kd = 0.35-0.38. Tryptic digestion of the middle peak produced immunoreactivity which coeluted with the standard. Larger forms were also found in plasma of women in the third trimester of pregnancy and during labour but not in eluates from superfused placental fragments which had only CRH41-sized material. These data indicate that tissue-specific post-translational processing occurs for CRH, and suggests that the link between synthesis and secretion is more immediate in the placenta than hypothalamus.

Chromatography, Gel↗
PubMed1988

Fluorodeoxyuridine modulation of the incorporation of iododeoxyuridine into DNA of granulocytes: a phase I and clinical pharmacological study.

The amount of iododeoxyuridine (IdUrd) incorporated into DNA determines the degree of radiosensitization. Fluorodeoxyuridine (FdUrd) has been shown to biochemically modulate IdUrd incorporation into DNA in vitro and in vivo. In this Phase I study, these drugs were coadministered to patients during 14-day continuous i.v. infusion periods in order to investigate whether the incorporation of IdUrd into DNA in vivo could be increased without increasing the dose of IdUrd. IdUrd plasma concentrations and incorporation of IdUrd into DNA of granulocytes were measured by high-performance liquid chromatography. Up to 8.8% substitution of thymidine by IdUrd was observed. Even at 3.5 mg/m2/day FdUrd for 14 days (78% of the maximum-tolerated dose as a single agent), no clinically relevant enhancement of incorporation of IdUrd into DNA of granulocytes was observed. Also, no changes in plasma levels of IdUrd were observed with escalating doses of FdUrd. Toxicity patterns (stomatitis, diarrhea, and bone marrow depression) and isobologram analysis suggested that IdUrd and FdUrd had additive, rather than synergistic, effects.

Antineoplastic Combined Chemotherapy Protocols↗