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P Timmins

Publications and source records attributed to P Timmins.

32 records · Page 2Linked to original sources
PubMed1990

Differential scanning calorimetry characterization of process-induced variations in an ointment base.

Preparation of an experimental emollient wax-gelled ointment base by two processes differing only in cooling rate produced material with markedly different physical properties. Differential scanning calorimetry showed that a major endotherm, possibly related to a phase change in a major triglyceride wax component, Synchrowax HGLC, was different in the two products. Mean enthalpies for this major endotherm for the two products were 7.36 J g-1 (s.d. = 0.49, n = 5) in slow cooled samples and 4.35 J g-1 (s.d. = 0.21, n = 5) in fast cooled samples. The degree of order of the Synchrowax HGLC in the ointment is suggested as being different in the two preparations and it is this that controls the physical properties of the ointment.

Calorimetry, Differential Scanning↗
PubMed1989

The stimulation of metallothionein synthesis in neuroblastoma IMR-32 by zinc and cadmium but not dexamethasone.

Metallothioneins are a class of cysteine-rich and low molecular weight, metal-binding proteins that are inducible by a wide variety of agents, including metal ions, such as cadmium and zinc, glucocorticoid hormones, interferon, and tumor promoters. In an effort to delineate the regulation of the synthesis of the recently identified brain metallothionein-like protein, a study was undertaken to compare the induction of metallothionein in human neuroblastoma IMR-32 cells by zinc, cadmium, and dexamethasone using the human Chang liver cells as a control. Both cadmium (1 microM) and zinc (100 microM) significantly enhanced the incorporation of [35S]cysteine into metallothioneins isolated from both neuroblastoma and Chang liver cells. Dexamethasone in concentrations of 10 microM stimulated the synthesis of metallothionein in the Chang cells, whereas it had no effects on the synthesis of metallothionein in the neuroblastoma cells at concentrations ranging from 2.5--100 microM. The degree of stimulation of metallothionein synthesis in the Chang cells by cadmium and zinc was significantly higher than seen in neuroblastoma cells. The neuroblastoma IMR-32 exhibited less tolerance to the toxicity of both cadmium and zinc than the Chang cells, which may correlate with the inherent ability of these ions to induce metallothioneins in these dissimilar cells. The results of these studies are interpreted to indicate that the factors regulating the synthesis of metallothioneins in the Chang and neuroblastoma cells are not identical, suggesting also of the presence of dissimilar regulatory mechanisms in the liver and brain.

Animals↗
PubMed1986

Proliposomes: a novel solution to an old problem.

A procedure is described for the preparation of a dry, free-flowing granular product which, on addition of water, disperses/dissolves to form an isotonic liposomal suspension, suitable for administration either intravenously or by other routes. Various parameters have been investigated including the suitability of sorbitol and sodium chloride as carrier materials, the nature of the lipid(s) in the formulation, and the extent of lipid loading onto the carrier. These factors are shown to have a marked effect on both the dry product and the hydrated liposomes.

Amphotericin B↗
PubMed1983

Degradation of hydrocortisone in a zinc oxide lotion.

An extemporaneous topical steroid formulation, prepared from a zinc oxide lotion and hydrocortisone lotion BPC, had poor stability. Hydrocortisone decomposed mainly to the 21-aldehyde, but other degradation products were also identified by HPLC. The decomposition process could be described by first-order kinetics. Stabilization methods employing pH adjustment, antioxidants and chelating agents were unsuccessful. The study emphasizes the dangers of diluting commercial formulations with unrecommended bases and indicates the modes of decomposition of hydrocortisone in a formulation.

Drug Stability↗
PubMed1980

Newborn minor physical anomalies and problem behavior at age three.

The authors followed up 136 three-year-olds who had high or low scores for minor physical anomalies of face, head, hands, and feet at birth. Interviews with parents revealed that high-anomaly infants were somewhat more likely to have problem behaviors at age three; this was particularly true for hyperactive-impulsive behavior for boys. Preschool teachers' ratings of hyperactivity, however, did not show a significant relationship to anomaly score. The results suggest some congenital contributors to behavior disorders of childhood, but the relationship between anomalies and problem behavior is weak and limits clinical usefulness of this measure when used alone for identifying a high-risk population.

Child Behavior Disorders↗