Search PubMed⌕ Search

Biomedical subjects

R Johnson

Publications and source records attributed to R Johnson.

At least 559 records · Page 31Linked to original sources
PubMed1982

Management of the primary dentition in vitamin D-resistant rickets.

Vitamin D-resistant rickets (familial hypophosphatemia) is a systemic disease secondary to defective renal-tubular reabsorption of phosphate. The major oral manifestations are spontaneous abscesses in a caries-free dentition. Pulpotomies or extractions were frequently described in the dental literature as the therapies of choice. This article presents a new prophylactic approach utilizing zinc oxide--eugenol pulpectomies and full crown coverage in an attempt to retain the primary dentition and prevent abscess formation.

Abscess↗
PubMed1982

CNS putative L-prolyl-L-leucyl-glycinamide (PLG) receptors, brain and lymphocyte dopamine receptors.

1. In view of previously demonstrated modulatory effects of PLG on the sensitivity of central dopamine receptors, we developed a radioligand binding assay to identify specific binding sites of PLG in rat and normal human brain. 2. 3H-PLG binds specifically to rat striatum exhibiting high affinity (KD = 4.69 +/- 0.50 nM) saturability (Bmax = 9.20 +/- 0.30 fmoles/mg protein) and reversibility; the highest density of specific PLG binding sites occurring in the striatum, followed by the hypothalamus and cerebral cortex. 3. Saturable, high-affinity binding sites of PLG were identified in human striatum. The substantia nigra was enriched with the highest level of specific PLG binding sites. 4. Dopamine receptors were identified in human lymphocytes. 5. The results are compatible with the hypothesis that differential modulation of CNS dopamine receptors by PLG is functionally associated with interacting with specific PLG binding sites in the rat and human brain, and pose implications for Parkinson's disease and tardive dyskinesia.

Animals↗
PubMed1982

RBC and plasma levels of haloperidol and clinical response in schizophrenia.

The authors conducted a fixed-dose study of haloperidol blood levels and clinical response in schizophrenic in patients and found that those with steady-state RBC haloperidol levels in the range of 2.4--5.4 ng/ml showed greater improvement than those with lower or higher levels. They found a similar , although nonsignificant, curvilinear relationship between plasma haloperidol levels and clinical response. These findings suggest that the relationship between haloperidol blood levels and clinical response fits a therapeutic window for the treatment of schizophrenia.

Adolescent↗
PubMed1982

Pedodontics.

Explore the source record for details and available documents.

Child↗
PubMed1982

Colloid cyst of the third ventricle. A scanning and transmission electron microscopic study.

Three colloid cysts of the third ventricle were examined by both transmission (TEM) and scanning electron microscopy (SEM). There was morphological diversity of the cyst surface on SEM, with ciliated and non-ciliated cells present. In some areas, the non-ciliated cells were more numerous and extended above the surface. Individual non-ciliated cells show a wrinkled cell surface and bleb-like structures. The TEM findings correlated well with SEM, revealing two cell types. The non-ciliated cells appeared to have both exocrine and apocrine activity. In ciliated cells, abnormal cilia were related to abnormal centrioles; also present were highly abnormal microvilli. The appearance of the surface was similar to a normal ventricular surface. By allowing a greater assessment of cell types and their distribution, SEM has added one additional dimension in the evaluation of colloid cysts and their possible derivation.

Adult↗
PubMed1982

Bilateral retinal infarction in disseminated aspergillosis.

A 10-month-old boy presented with malnutrition and fever of unknown origin. Treatment with steroids, antibiotics and total parenteral nutrition was unsuccessful, and progressive thrombotic complications led to death in 5 weeks. An antemortem diagnosis of embolic occlusion of both central retinal arteries was confirmed at autopsy. Aspergillus had invaded the blood vessels of many organs, including the eyes, and had proliferated within their lumina, causing thrombi and emboli to form and resulting in extensive tissue infarction, necrosis and hemorrhage.

Aspergillosis↗
PubMed1981

Effects of rifampicin on the relationship of R6K replicating forms to the folded chromosomal complex of Escherichia coli.

An examination of the relationship of R6K plasmic DNA to the folded chromosome has shown that replicating forms of this plasmid, when compared to the non-replicating forms, were preferentially associated to the apparently mediated by RNA molecules. In this report we show that inhibition of RNA synthesis with rifampicin prior to pulse-labeling cells harboring R6K plasmid DNA resulted in the release of the replicating forms. Analyses of the single-stranded length of rifampicin-released nascent molecules indicate that continuous replication of R6K plasmid DNA to unit length was not affected by the presence of rifampicin. Thus, it appears that complexing was not required for continued synthesis of this plasmid. Further, the inhibition of protein synthesis does not appear to alter the complexing frequency of R6K plasmid DNA to the folded structure. These results suggest that active RNA synthesis is required for maintaining the association of the replicating forms to their replicational site(s).

Chromosomes, Bacterial↗