PubMed Health⌕ Search

Biomedical subjects

R L Miller

Publications and source records attributed to R L Miller.

At least 235 records · Page 13Linked to original sources

A diurnal rhythm of immunoreactive alpha-melanocyte-stimulating hormone in discrete regions of the rat brain.

A significant diurnal variation in alpha-melanocyte stimulating hormone (alpha-MSH) concentrations was observed in discrete regions of the rat brain. During the 12 h light: 12 h dark cycle, alpha-MSH concentrations in each case were highest during the light period and lowest during the dark period. At 09.00 h, 3 h after lights were turned on, the peak alpha-MSH concentration occurred in the median eminence, the arcuate and dorsomedial hypothalamic nuclei and the periventricular thalamic nucleus. The paraventricular and anterior hypothalamic nuclei had highest alpha-MSH concentrations at 13.00 h. In the medial preoptic nucleus, the peak alpha-MSH concentrations appeared at 17.00 h. These changes in alpha-MSH content may reflect an alpha-MSH role in circadian variations in behavioral and neuroendocrine processes.

Animals↗

Inherited human collagen lysyl hydroxylase deficiency: ascorbic acid response.

A patient is described with congenital hypotonia, lax joints, friable skin, hemorrhagic scars, high-arched palate, and borderline microcornea. Acid hydrolyzed whole skin collagen had a reduced hydroxylysine content of 0.5 residues per 1,000 as compared to 5.1 +/- 0.7 in control skin. Collagen lysyl hydroxylase in dialyzed subcellular fractions of cultured skin fibroblasts required L-ascorbate as a principal cofactor. Activity of this enzyme in cultured skin fibroblasts derived from this patient, his father, and mother were 17%, 66%, and 39% of control values, respectively. Collagen prolyl hydroxylase activity was normal. Pharmacologic amounts of oral vitamin C (4 gm/day) produced an increase and withdrawal resulted in abrupt diminution of urinary excretion of hydroxylysine. Over a two-year period the patient's wound healing and muscle strength improved and corneal diameter increased. Hydroxylysine content of the skin did not increase.

Ascorbic Acid↗

Elevated prostaglandin production in cultured cells from a patient with fibrodysplasia ossificans progressiva.

Prostaglandin E production was measured in cells cultured from both a fibromatoid lesion and a normal area of skin in a patient with fibrodysplasia ossificans progressiva. The synthesis of prostaglandin E-like material (iPGE) was ten- to twenty-fold greater in cells cultured from the patient's fibromatoid lesion than in fibroblasts obtained from her normal skin. Addition of indomethacin in vitro resulted in a greater than 95% reduction of iPGE production in both cell cultures. These observations appear to warrant further investigation in additional patients, with this disease.

Cells, Cultured↗

Oral exfoliative cytology.

Oral exfoliative cytology can be a powerful tool for early detection of malignant and premalignant lesions as well as for some viral and fungal infections, if the limitations of the method are thoroughly understood and appreciated by the dental clinician. The rationale for oral cytology is developed and documented, and interpretations of the results are explained. Advantages and disadvantages of this technique are given and indications and contraindications for this diagnostic adjunct are discussed. A simple method involving the use of inexpensive equipment in the office is suggested.

Cell Nucleus↗

Effect of ara-T on the replication of herpes simplex virus, varicella-zoster virus and cytomegalovirus.

The thymidine analogue, 1-beta-arabinofuranosylthymine (ara-T), has previously been found to selectively inhibit herpes simplex virus (HSV) replication. At a relatively non-toxic concentration (50 microgram/ml), ara-T reduced HSV yields by a factor of 10,000-100,000. Ara-T was also effective in inhibiting the replication of variecella-zoster virus (VZV) in vitro in human embryo fibroblasts, completely preventing VZV-specific cytopathic effects (CPE). Ara-T reduced the cell-free virus and plaque-forming cell (PFC) yields of VZV as well as of the simian varicella-like virus, Delta herpesvirus. In contrast to HSV and VZV, cytomegalovirus (CMV) replication was relatively resistant to ara-T. Neither CPE nor the incorporation of 3H-thymidine into acid-insoluble material in CMV-infected cells was markedly affected. Interpretation of these results with regard to virus-induced deoxypyrimidine kinase is discussed.

Arabinonucleosides↗