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Biomedical subjects

R Billings

Publications and source records attributed to R Billings.

At least 19 recordsLinked to original sources
PubMed2004

Clinical outcomes for Early Childhood Caries (ECC): the influence of health locus of control.

AIM: To assess the relationship between clinical outcomes for children treated for ECC and health locus of control. STUDY DESIGN AND METHODS: The study cohort consisted of 79 children (42 males, 37 females) treated for ECC; age range was 2.3-7.3 years (mean 4.2 years) at the time of entry into the study. A questionnaire [developed by DeVellis et al., 1993] was administered to each child's parent(s) on the day of dental surgery. This questionnaire examined the expectation that healthcare outcomes in children are influenced by one of the following loci of control: Professional, Parent, Child, Media, Fate and Divine. The cohort was evaluated for new caries lesions at 6 months post dental surgery. Relapse was defined as the presence of new smooth surface caries lesions. STATISTICS: For each locus, the scores for the Relapse versus Non-relapse groups (returning patients) and the scores for the returning versus non-returning patients were compared using t-tests. RESULTS: 57 children (72%) returned for follow-up and 21 of these 57 (37%) relapsed. No statistically significant difference for Relapse versus Non-relapse groups was indicated with respect to the scores for any locus parameter (p values ranged from 0.35 to 0.95). Returning parents (N=57) versus non- returning parents (N=22) exhibited statistically significant differences with respect to the Parent, Divine and Fate loci. Returning parents exhibited higher scores on the Parent locus (p=0.0392) and lower scores on the Fate (p=0.0024) and Divine (p=0.0031) loci. CONCLUSION: 1). The relapse rate (37%) was high and rapid for children treated for ECC; 2). no meaningful difference existed between the Relapse versus Non-relapse groups with respect to each health locus of control parameter; 3). parents who returned for follow-up care appeared to have an internal health locus of control while those who did not return had an external locus.

Child↗
PubMed2004

Clinical outcomes for Early Childhood Caries (ECC): the influence of salivary mutans streptococci levels.

AIM: To assess the relationship between clinical outcomes for children treated for Early Childhood Caries (ECC) and salivary mutans streptococci (MS) levels. STUDY DESIGN AND METHODS: The study cohort consisted of 79 children (42 males, 37 females) treated for ECC, aged from 2.3 to 7.3 years at time of entry. Whole non-stimulated saliva samples were obtained from each subject prior to dental surgery and at 6 mths post dental surgery, by saturating a cotton swab in the saliva pooled in the floor of the mouth. Samples were placed into PBS on ice and processed within 2 hours. Samples were sonicated, serially diluted and plated onto MSB and SBA agar plates, then incubated 48 hours anaerobically; SBA plates were incubated an additional 24 hours aerobically. The MS level in each sample was expressed as a percentage of the total cultivable flora. The cohort was evaluated for new caries lesions at 6 months post dental surgery. Relapse was defined as the presence of new smooth surface caries lesions. STATISTICS: Comparisons between Relapse (R) and Non-Relapse (NR) groups with respect to mutans streptococci levels were performed using Wilcoxon tests. Within group comparisons were performed using Wilcoxon signed-rank tests. RESULTS: 57 children (72%) returned for the 6 months examination and 21 of these subjects (37%) relapsed. No statistically significant difference in median salivary MS levels existed between the R (0.20%) and NR (0.033%) groups at baseline (p=0.647) or at 6 months post dental surgery (R=0.03%; NR=0.01%; p=0.273). A statistically significant difference between baseline and 6 months post dental surgery was noted in the median salivary MS level within the R group (p=0.0007) and within the NR group (P<0.0001). CONCLUSIONS: The relapse rate (37%) was high and rapid for children treated for ECC. Dental surgery resulted in a statistically significant reduction in salivary MS reservoirs for children treated for ECC. However, this did not translate into acceptable clinical outcomes.

Child↗
PubMed1996

Interlaboratory validation of a new assay for DNA-protein crosslinks.

In 1992, a simple and sensitive assay for detecting DNA-protein crosslinks was developed [1]. In an effort to facilitate the greater use of the assay, a number of studies were conducted to evaluate its reliability and reproducibility. During this work, the assay was used to assess whether various metals and other compounds could induce crosslinks in cultured human lymphocytes (Epstein-Barr virus-transformed Burkitt's Lymphoma cell line). Potassium permanganate, mercury chloride, lead nitrate, magnesium perchlorate, aluminum chloride, and cadmium chloride did not induce DNA-protein crosslinks at either cytotoxic or non-cytotoxic levels. Copper sulfate, arsenic trioxide, and potassium chromate induced DNA-protein crosslinks only at cytotoxic concentrations. Acute lethality of the cells was assessed immediately after exposure to metals by trypan blue exclusion while long-term lethality was assessed by cell proliferation and trypan blue exclusion following an incubation period of 5 days after exposure to the metal compound. All metals exhibited more toxicity in the long-term lethality assay compared to the short-term assay. The cultured human lymphocytes treated with various doses of lead acetate, cadmium chloride, arsenic trioxide and copper sulfate, as well as cis-platinum and chromate, were sent to four different laboratories to compare the reliability and reproducibility of the DNA-protein crosslink assay. Depending on the chemical studied, there were quantitative differences in the results observed among the various laboratories using the assay. However, all laboratories generally showed that cis-platinum, chromate, arsenic trioxide and copper sulfate induced DNA-protein crosslinks at levels that produced acute cytotoxicity, whereas cadmium chloride and lead acetate did not.

Arsenic Poisoning↗
PubMed1994

Homicidal somnambulism: a case report.

A case of a homicide and an attempted homicide during presumed sleepwalking is reported in which somnambulism was the legal defense and led to an acquittal. Other possible explanations including complex partial seizures, dissociative state, rapid eye movement sleep behavior disorder and volitional waking behavior are discussed. The evidence supporting the probability that this act occurred during an episode of somnambulism and sleep-related confusional arousal is reviewed and weighed. This evidence includes personal and family history of somnambulism and related disorders; neurological, psychiatric and psychological assessments; presence of possible precipitating factors; and polysomnographic data.

Adult↗
PubMed1987

Cellular catabolism of recombinant tissue-type plasminogen activator. Identification and characterization of a novel high affinity uptake system on rat hepatocytes.

The uptake, internalization, and intracellular degradation of 125I-labeled recombinant tissue-type plasminogen activator (rt-PA) by isolated rat hepatocytes was investigated. Incubation at 37 degrees C resulted in internalization of 125I-rt-PA, followed by the appearance of labeled trichloroacetic acid-soluble material in the incubation media due to degradation of rt-PA. Degradation of rt-PA was inhibited by the presence of NH4Cl (10 mM) or chloroquine (1 mM) (lysosomal tropic agents) in the incubation media. This suggests that rt-PA degradation occurs intracellularly, perhaps within the lysosomes. 125I-rt-PA was taken up by rat hepatocytes through a specific, high affinity mechanism with half-maximal uptake at 10 nM. Uptake of 125I-rt-PA was not inhibited by glycopeptides isolated from rt-PA nor by several other glycoproteins known to be cleared by identified hepatic receptors. These results suggest that the uptake of rt-PA by rat hepatocytes involves a receptor specific for t-PA and is not mediated by a carbohydrate-specific receptor.

Animals↗
PubMed1981

Early evaluation of Ia monoclonal antibodies in prolonging non-human primate skin allograft survival.

Monoclonal antibodies (MCA) specific against one subset of lymphocytes (anti-B) were used in treating skin allograft rejection in Rhesus monkeys. Rhesus monkeys were treated daily with intravenous MCA until the skin graft was rejected. The dose of the MCA was adjusted according to the peripheral B-cell counts obtained by rosetting technique as well as by indirect immunofluorescence. We finally achieved a safe dose, though the margin of safety was narrow. We also noted that the B-cell count dropped to a significant degree and that the survival of the skin graft was prolonged.

Animals↗
PubMed1976

The effect of nisoxetine (Lilly compound 94939), a potential antidepressant, on biogenic amine uptake in man.

Preclinical studies with nisoxetine (Compound 94939) (3-[o-Methoxyphenoxy]-N-methyl-3-phenylpropylamine HCl) had shown it to have antidepressant properties and to be almost devoid of anticholinergic activity and depressant effects on cardiac conduction (in contrast to the commonly used tricyclic antidepressants from which nisoxetine significantly differs in structure). Placebo and nisoxetine (10-20 mg b.d. for 7 days) were administered to normal volunteers in a single-bind crossover study. Adverse side effects were minimal. There were no significant changes in heart rate or blood pressure seen when no other drugs were given. The effect of nisoxetine on uptake of biogenic amines was utilized to study its mechanism of action. The transient rise in blood pressure seen after an intravenous bolus of tyramine decreased by one-half to two-thirds while the rise in blood pressure upon continuous noradrenaline infusion was enhanced some two-to eight-fold. Both effects occurred after on dose and were greater with larger doses and chronic administration. In vitro, nisoxetine inhibits 5-HT uptake into platelets. However, platelets harvested from subjects receiving chronic nisoxetine administration did accumulate 5-HT. Plasma concentration of nisoxetine in these individuals was shown to be lower than that needed to block 5-HT uptake. We concluded that nisoxetine, in safe doses, specifically increased the sensitivity of noradrenaline and decreased tyramine responsiveness, presumably by blocking uptake at the axonal membrane. In contrast, in these clinical doses it had virtually no effect on 5-HT uptake into platelets.

Adult↗
PubMed1975

Blood and urine gold levels during chrysotherapy for rheumatoid arthritis.

In this study the value of undertaking routine blood and urine estimations was assessed in relation to achieving maximum efficacy and safety in chrysotherapy. It was found that a favourable response to gold was forthcoming in approximately two-thirds of patients and occurred irrespective of the patients' disease duration or severity, or the mean serum gold level or the mean urinary gold excretion, estimated immediately before the next gold injection was due. The presence of rheumatoid nodules and the patients' advancing age were associated with a less favourable clinical response to gold. Those patients who derived a marked benefit from chrysotherapy did so significantly earlier in their course than those who derived only moderate benefit. A frequent correlation was seen in individual patients between serum gold levels and urinary gold excretion. This was most marked in those patients showing a favourable response to gold.

Adult↗
PubMed1975

A double-blind cross-over trail of Prenazone and aspirin in the management of rheumatoid arthritis.

A double-blind cross-over trial of Prenazone 600 mg and Aspirin 4 g daily was carried out on 20 patients suffering with rheumatoid arthritis. The analgesic and anti-inflammmatory activity was indistinguishable from that of aspirin under the conditions of the trail. Twelve patients expressed a general preference for Prenazone and six for aspirin. Prenazone appeared to be well tolerated and free from serious side-effects. These results suggest that it will be a useful drug in the management of rheumatoid arthritis.

Aged↗
PubMedDate not supplied

Clinical outcomes for early childhood caries: influence of aggressive dental surgery.

PURPOSE: The objective of this study was to assess the relationship between the number of stainless steel crowns (SSCs) placed, number of surfaces at risk (SAR) post dental surgery, and the risk for relapse in patients treated for Early Childhood Caries (ECC). METHODS: The study population consisted of 57 children treated for ECC under general anesthesia, ranging in age from 2.3 to 7.3 years old at the time of entry. Dental surgery utilized an aggressive approach: teeth that had necrotic pulps or were nonrestorable were extracted; decayed primary mandibular incisors that could not be treated by stripping were extracted; primary maxillary incisors with 3 or more carious surfaces were extracted; single-surface lesions of primary molars that did not compromise cusp integrity were restored with intracoronal amalgam restorations; primary maxillary, incisors and canines with smooth-surface lesions affecting 2 or less surfaces were treated with intracoronal composites; primary molars and canines requiring vital pulp therapy were restored with SSCs; primary molars with caries lesions affecting 2 or more surfaces (including smooth-surface, white-spot lesions) were restored with SSCs; primary canines with caries affecting 3 or more surfaces were restored with stainless steel crowns; topical fluoride was applied after all restorative therapy was completed. The cohort was examined for new caries lesions 6 months post dental surgery. Relapse was defined as the presence of new smooth-surface caries lesions as defined by Radike. Comparisons between relapse (R) and nonrelapse (NR) groups, with respect to the number of SSCs placed and the number of SAR, were performed using t tests and Wilcoxon tests. A 0.05 level of significance was employed in all statistical tests. RESULTS: Twenty-one of the 57 (37%) patients relapsed. No statistically significant difference for the number of SSCs placed or SAR existed between the R group (SSCs: mean = 4.57, median = 4 +/- 2.18; SAR: mean = 39.76, median = 40 +/- 13.62) and NR group (SSCs: mean=5.44, median = 5.5 +/- 2.62; SAR: mean = 39.98, median = 39.5 +/- 15.19). CONCLUSIONS: The risk for relapse in children treated for ECC is not associated with the number of SSCs placed or SAR; aggressive dental surgery for ECC does not result in acceptable clinical outcomes.

Child↗