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Biomedical subjects

R Waller

Publications and source records attributed to R Waller.

11 recordsLinked to original sources
PubMed1986

High doses of fluoride do not affect cyclic AMP levels in human and rat plasma or urine.

The effect of fluoride ingestion on plasma and urinary cyclic AMP levels was studied in healthy volunteers, children undergoing prophylactic fluoride treatment and in rats. In the first series of experiments fluoride ingestion led to a 20-fold increase in plasma fluoride concentration, which was unrelated to changes in plasma cyclic AMP. The only significant effect on plasma cyclic AMP occurred prior to fluoride, an effect attributed to stress. In the second series performed in children increases in urinary F- of up to 200-fold were associated with slight but nonsignificant changes in cyclic AMP excretion. In rat experiments the blood sampling procedure was associated with a rise in plasma cyclic AMP. When this was prevented by pretreatment with propranolol (3 mg/kg), the effect of fluoride (50 ppm in the drinking water) was tested. A fall in urine production was not associated with any change in cyclic AMP excretion or in nephrogenic cyclic AMP. It is concluded that if fluoride alters cyclic AMP in rats and man the effect is small and easily masked by other factors such as catecholamine release following stress.

Adult↗
PubMed1982

Full-thickness eyelid biopsy for presumed carcinoma in situ of the palpebral conjunctiva.

A biopsy-proven diagnosis of carcinoma in situ of the palpebral conjunctiva should always evoke doubt. This change may represent pagetoid spread of an occult sebaceous gland carcinoma. The conjunctival changes may be subtle, preceding the formation of any obvious mass in the eyelid. In this situation, full-thickness eyelid biopsy should be considered as a possible alternative to diagnosis accurately the disease process. The authors present two cases where biopsy of chronically inflamed palpebral conjunctiva was at first diagnosed as carcinoma in situ. Full-thickness eyelid biopsy was performed at varying times following the conjunctival biopsy. Sebaceous gland carcinoma was then diagnosed in each case. The pathogenicity of carcinoma in situ differs markedly from sebaceous gland carcinoma. A palpebral conjunctival biopsy diagnosed as carcinoma in situ should arouse suspicion that a more serious pathologic process may be present. Full-thickness eyelid biopsy may be appropriate under such circumstances.

Adenocarcinoma↗
PubMed1975

Activated macrophages in congenitally athymic "nude mice" and in lethally irradiate mice.

Resistance to the facultative intracellular bacteria, Brucella abortus and Listeria monocytogenes, is principally the result of acquisition of enhanced antibacterial activity by host macrophages, probably in response to lymphokines released by T lymphocytes. However, the present paper describes a surprisingly high resistance on the part of both congenitally athymic "nude" mice and of lethally irradiated mice compared with normal controls. This enhanced bactericidal activity was evident 24 hr after infection, and could also be demonstrated in macrophages from nude mice cultured in vitro. It was concluded that the macrophages of these animals had been activated before infection.

Animals↗
PubMedDate not supplied

Preliminary characterisation of chlorarachniophyte mitochondrial DNA.

The division Chlorarachniophyte comprises amoeboflagellate protists with complex chloroplasts derived from the endosymbiosis of a eukaryotic alga. Analysis of chlorarachniophyte chromosomal DNAs by pulsed-field gel electrophoresis revealed an apparently linear 36-kb chromosome that could not be ascribed to either the host or endosymbiont nuclei. A single eubacterial-like small subunit ribosomal RNA gene is encoded on this chromosome and phylogenetic analyses places this gene within a clade of mitochondrial genes from other eukaryotes. High resolution in situ hybridization demonstrates that transcripts of the small subunit ribosomal RNA gene encoded by the 36-kb chromosome are exclusively located in the mitochondria. The 36-kb chromosome thus likely represents a linear mitochondrial genome. Small amounts of an apparently dimeric (72 kb) form are also detectable in pulsed-field gel electrophoresis.

Animals↗