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Biomedical subjects

G Bacon

Publications and source records attributed to G Bacon.

6 recordsLinked to original sources
PubMed2000

Evaluation of the activity of a novel metabotropic glutamate receptor antagonist (+/-)-2-amino-2-(3-cis and trans-carboxycyclobutyl-3-(9-thioxanthyl)propionic acid) in the in vitro neonatal spinal cord and in an in vivo pain model.

The cyclobutylglycine (+/-)-2-amino-2-(3-cis and trans-carboxycyclobutyl-3-(9-thioxanthyl)propionic acid) (LY393053) has been identified as a functionally potent metabotropic glutamate receptor antagonist. It is most potent on the two group I metabotropic glutamate receptors, 1alpha and 5alpha, with IC50 values of 1.0+/-0.4 microM and 1.6+/-1.4 microM, respectively. In this study, LY393053 has also been evaluated electrophysiologically on native group I metabotropic glutamate receptors in an in vitro spinal cord preparation as well as behaviourally, in a mouse model of visceral pain. LY393053 dose-dependently antagonised group I agonist, (RS)-3, 5-dihydroxyphenylglycine, or a broad-spectrum agonist (1S,3R)-amino-1,3-cyclopentanedicarboxylic acid-induced depolarisation of spinal motoneurons. The apparent Kd values were estimated to be 0.3 microM against (RS)-3, 5-dihydroxyphenylglycine-induced depolarisation and 0.5 microM against (1S,3R)-amino-1,3-cyclopentanedicarboxylic acid-induced depolarisation, respectively. On the other hand, the dorsal root-ventral root potential elicited at 8 x threshold was depressed by LY393053 with IC50 values of 9.0+/-0.7 microM and 12.7+/-1.7 microM on monosynaptic and polysynaptic responses, respectively. When investigated using the mouse acetic acid writhing test, LY393053 showed significant analgesic effects at doses of 1-10 mg/kg intraperitoneally. An ED50 value of 6.0 mg/kg was obtained in this test. By revealing a potent effect of LY393053 in antagonising the native group I metabotropic receptor-mediated responses in the spinal cord in rodents, and an antinociceptive efficacy in a mouse visceral pain model, these results, therefore, provide additional evidence in support of the analgesic potential of metabotropic glutamate receptor antagonists.

Acetic Acid↗
PubMed1990

Intellective functioning and strategy use in children with insulin-dependent diabetes mellitus.

The cognitive development of children with either early or late onset insulin-dependent diabetes mellitus (IDDM) was investigated with tasks measuring intellectual ability, memory, and academic progress. In addition, children's perceptions of their competence and parents' perspectives on family functioning and their children's behavior were compared. It was found that children with IDDM scored within the normal range on standardized measures of intelligence and academic performance but evidenced some school difficulties, as reflected in subscale performance as well as in their need of remedial education services. Further, evidence was found to suggest deficiencies in children's use of strategies to organize and recall information, particularly for those with early onset of disease. Children's perceived self-competencies and parents' reports of family functioning were strikingly similar across groups. However, parents of those children whose illness began prior to age 5 reported their children to have poor attention spans and difficulty completing tasks.

Achievement↗
PubMed1989

Humoral immune response to selected subgingival plaque microorganisms in insulin-dependent diabetic children.

Juvenile diabetics have been shown to have an increased susceptibility to gingivitis and periodontitis following puberty. However, little data are available on changes in the microbial flora that occur at the onset of puberty. This study was performed to determine if antibacterial antibody titers to selected periodontal disease-associated microorganisms might be helpful in revealing changes in plaque flora at the onset and conclusion of puberty. Sera was obtained from 35 subjects (ages 7 to 18 years) selected from a population of insulin-dependent diabetics. The subjects were given a thorough medical examination which included an assessment of sexual maturation and a dental examination which included the recording of onset and magnitude of bleeding according to the papillary bleeding score. Antibody titers to A. naeslundii (AN), B. intermedius (BI), B. gingivalis (BG), F. nucleatum (FN), A. actinomycetemcomitans (AA), C. ochracea (CO) and T. denticola (TD) were determined using the microELISA. Stratification of antibody titers by age groups (less than or equal to 12 years, 12 to 15 years, greater than 15 years) revealed that titers to AN increased significantly (P less than 0.025, ANOVA) and progressively (P less than 0.05, regression analysis) with increasing age. In contrast, the titers to FN were maximal in the under 12 year group and decreased with age (ANOVA, P less than 0.05; regression analysis, P less than 0.05). There were no significant variations in titers observed for the other microorganisms. Stratification by sexual maturity revealed a similar progressive decrease of the titer to FN (ANOVA, P less than 0.05; regression analysis, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗
PubMed1983

Puberty gingivitis in insulin-dependent diabetic children. I. Cross-sectional observations.

This cross-sectional study examined the gingivitis occurring at puberty in a population of insulin-dependent juvenile diabetics. Seventy-seven children between the ages of 6 and 15 years were examined for gingivitis levels, stages of pubertal maturation and blood levels of glucose and glycosylated hemoglobin. Bacterial plaque was sampled from one or more approximal tooth surfaces of every subject and cultured under anaerobic and aerobic conditions on nonselective and selective media. The total cultivable flora and percentage of certain presumptive periodontopathic bacteria were determined. Before puberty, children with "high" levels of glycosylated hemoglobin also had higher gingivitis levels than children with "normal" metabolic control of diabetes. During puberty, the level of gingivitis increased independently from both fasting blood glucose levels and per cent glycosylated hemoglobin. The microbiota of marginal plaque was predominantly composed of facultatively anaerobic bacteria. The percentages of Capnocytophaga sp and Actinomyces naeslundii were statistically higher at the onset of puberty, suggesting that a specific bacterial shift in the microbial composition of marginal plaque occurs in response to host changes in juvenile diabetic children at this age period.

Adolescent↗
PubMed1978

Sequential advancing flexion retention attachment: a locking device for the wrist-driven flexor hinge splint.

The Sequential Advancing Flexion Retention Attachment (SAFRA) was developed for cervical spinal cord-injured patients with a muscle grade of poor to fair in the wrist extensors. It is used on a standard wrist-driven flexor hinge hand splint with adjustable tenodesis bar. Through the development of the SAFRA, maintained prehension can be obtained without externally powered devices such as CO2 or electrically powered orthoses. The patient's increased functional abilities are discussed and advantages summarized.

Adult↗