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Biomedical subjects

P J Loos

Publications and source records attributed to P J Loos.

14 recordsLinked to original sources
PubMed1995

Arch dimensional changes in children with idiopathic short stature treated with recombinant growth hormone: a five-year study.

Recombinant human growth hormone (rhGH) increases stature when administered to non-GH-deficient idiopathic short statured children. The aims of this investigation were to determine pretreatment arch dimensions of short statured children (height > or = 2 S.D. below mean for age) and to evaluate their response to rhGH administration by measuring arch-dimensional changes over 5 years of rhGH treatment. Dental casts of 28 short subjects (22 male, 6 female) and of age/gender-matched controls of normal stature were analyzed using a digital imaging system. Four measures of arch width and one of arch depth were calculated for each maxillary and mandibular cast. Subjects receiving orthodontic care were eliminated from the study at the initiation of treatment. Z-scores were calculated to allow for pooling of data. Prior to rhGH treatment, all arch dimensions of the short statured subjects were smaller than the controls, with the exception of mandibular arch depth. Arch dimensions of the rhGH subjects did increase with the continued administration of rhGH. The control group also showed a significant trend for the arch dimensions to increase over time. The influence of rhGH treatment on arch dimensional changes over time remains equivocal based on the results of this investigation.

Adolescent↗
PubMed1993

The influence of growth hormone (rhGH) therapy on tooth formation in idiopathic short statured children.

The purpose of this preliminary study was to evaluate tooth formation in children with idiopathic short stature, before and during treatment with recombinant growth hormone (rhGH). Twenty-nine short-statured children ages 6 to 13 years were assigned into two treatment groups, an "experimental" group (n = 18), which received rhGH, and a "control" group (n = 11), which was observed for 1 year before commencing rhGH treatment. Clinical and radiographic records were obtained at the initial, year 1, and year 2 visits. Tooth formation and stature were assessed by calculating Z-scores, appropriate for the age and gender of each child. Delta-Z scores, which measure the change in Z-score over time, were also calculated between annual visits. Height was measured and recorded every 3 months, and Z-score statural norms for age and gender were derived from the 1977 National Center for Health Services national probability sampling. Tooth formation standards were derived from Moorrees et al. A matched control sample for tooth development was derived from untreated children. Tooth formation was initially delayed although the degree of reduction in stature exceeded the initial degree of delay in tooth formation. During this 2-year study, rhGH therapy had a significant influence on acceleration or gain in stature, but did not have a significant influence on tooth formation.

Adolescent↗
PubMed1977

Pineal protein phosphorylation during serotonin N-acetyltransferase induction.

The activity of soluble protein kinase (ATP:protein phosphotransferase,EC 2.7.1.37) and pattern of nuclear protein phosphorylation was monitored in cultured rat pineal glands during the induction of serotonin N-acetyltransferase (acetyl-CoA:serotonin N-acetyltransferase;EC 2.3.1.5)by l-isoproterenol. A nuclear protein appears to be phosphorylated during the early stages of enzyme induction but is not phosphorylated at later stages of induction. This correlates well with the need for RNA synthesis associated with the induction process. The nuclear protein was also phosphorylated when the pineal glands were treated with dibutyryl 3':5'-cyclic AMP. The soluble protein kinase activity appeared to decline during mid-to-late stages of enzyme induction, but there was no concomitant increase in the particulate protein kinase activity.

Acetyltransferases↗
PubMed1975

Association of Streptococcus mutants with human dental decay.

The association of Streptococcus mutans with human dental decay was investigated by using several types of samples: (i) paraffin-stimulated saliva samples taken from children with from 0 to 15 decayed teeth; (ii) pooled occlusal and approximal plaque taken from children with no decayed or filled teeth, or from children with rampant caries of 10 or more teeth; (iii) plaque removed from single occlusal fissures that were either carious or noncarious. The results showed a significant association between plaque levels of S. mutans and caries. The strongest association, P < 0.0001, was found when plaque was removed from single occlusal fissures. Seventy-one percent of the carious fissures had S. mutans accounting for more than 10% of the viable flora, whereas 70% of the fissures that were caries free had no detectable S. mutans. Sixty-five percent of the pooled plaque samples from the children with rampant caries had S. mutans accounting for more than 10% of the viable flora, whereas 40% of the pooled samples from children that were caries free had no detectable S. mutans. Saliva samples tended to have low levels of S. mutans and were equivocal in demonstrating a relationship between S. mutans and caries.

Child↗