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Biomedical subjects

B Price

Publications and source records attributed to B Price.

At least 73 records · Page 4Linked to original sources

Continuous multiple location body temperature measurement of infants.

This study was done to evaluate the most suitable location of skin temperature sensors to enable long term temperature measurements of infants. A high accuracy eight channel temperature monitor was developed. Linear semiconductor sensor probes were constructed in association with this. System accuracy and stability were tested. Preliminary clinical studies have shown considerable variation from the core temperature for all surface measurement locations.

Body Temperature↗

Signal transduction by p21ras.

Experiments using the physical loading of purified recombinant p21 ras proteins into quiescent normal cells to analyze how the proteins stimulate DNA synthesis and morphological transformation are reviewed. The results indicate that oncogenic p21ras proteins rapidly activate a protein-kinase-C-dependent pathway and a protein-kinase-C-independent pathway. The activation of protein kinase C is absolutely required for p21ras to stimulate DNA synthesis but is not required for morphological transformation.

Animals↗

Cavernous haemangioma of the head and neck in the adult.

This paper reviews a personal experience of 51 cases seen over a 30 year period. Patients were treated in either a combined Head and Neck clinic or a Combined Ophthalmology clinic and a balanced view is thus represented. A method of grading the severity of the disease is described as well as a method of assessing response. This approach has not been proposed hitherto. It is generally concluded that the preferred treatment for small lesions is excisional surgery and for larger lesions carefully planned and highly localized radiation.

Adolescent↗

Scrape-loading of Swiss 3T3 cells with ras protein rapidly activates protein kinase C in the absence of phosphoinositide hydrolysis.

Scrape-loading has been used to analyse the biochemical function of purified p21ras protein. We have shown that scrape-loading oncogenic p21ras into quiescent Swiss 3T3 cells causes morphological transformation of 90% of the cell population within 15 h. Since large numbers of cells can be loaded with p21ras, early induced biochemical changes can be analysed. In this way we have shown that oncogenic p21ras causes rapid activation of protein kinase C five minutes after introduction of protein, but that ras protein fails to stimulate measurable inositol phosphate formation. It appears, therefore, that the stimulation of protein kinase C activity is due to a ras induced increase in diacylglycerol from a source other than inositol phospholipids. Efficient stimulation of DNA synthesis by oncogenic p21ras only occurs in the presence of insulin. This stimulation of DNA synthesis by ras is absolutely dependent on functional protein kinase C activity.

Cycloheximide↗

Proteolysis of cyclic AMP phosphodiesterase-II attenuates its ability to be inhibited by compounds which exert positive inotropic actions in cardiac tissue.

Extraction of frozen canine cardiac muscle rendered soluble over 90% of the cyclic AMP phosphodiesterase activity. The residual activity was membrane-bound. Ion exchange chromatography of the soluble activity on DE-52 allowed for the resolution of three distinct cyclic AMP phosphodiesterase fractions termed PDE-I, PDE-II and PDE-III in order of elution from the column by a linear NaCl gradient. The relative ratio of cyclic AMP phosphodiesterase activity exhibited by these three peaks was 1:0.65:0.82 and of cyclic GMP phosphodiesterase activity was 1:0.52:0.05 for PDE-I, PDE-II and PDE-III respectively. PDE-II and PDE-III were further purified by re-chromatography on DE-52. Fractions PDE-II and PDE-III were thermolabile at 50 degrees, decaying as single exponentials with half lives of 180 sec and 77 sec respectively. All three species exhibited non-linear Lineweaver-Burke plots for the hydrolysis of cyclic AMP, exhibiting both high and low affinity components. Hydrolysis of cyclic GMP by all three components obeyed normal kinetics, yielding linear plots. PDE-I was a Ca2+/calmodulin-activated species which exhibited a low Km for both cyclic AMP and cyclic GMP but hydrolysed cyclic GMP with a higher Vmax than for cyclic AMP. PDE-II exhibited a much lower Km for cyclic AMP than for cyclic GMP and a much higher Vmax for the hydrolysis of cyclic AMP. PDE-III exhibited a low Km for both cyclic AMP and cyclic GMP, however, its Vmax for cyclic AMP was about 40-fold higher than for cyclic GMP. Cyclic GMP acted as a potent inhibitor (IC50 = 6.3 microM) of cyclic AMP hydrolysis catalysed by PDE-III but not of the hydrolysis of cyclic AMP by PDE-II (IC50 = 33.2 microM). The phosphodiesterase inhibitors milrinone, CI-930, UK-35,493, carbazeran and buquineran acted as potent inhibitors of cyclic AMP hydrolysis catalysed by both PDE-II and PDE-III enzymes. They did not inhibit PDE-I activity. PDE-II, when prepared in the absence of protease inhibitors exhibited a reduced potency to inhibition by these compounds. Treatment of purified PDE-II with trypsin caused a reduction in enzyme activity and reduced dramatically the sensitivity of PDE-II activity to inhibition by these various compounds. The action of proteolysis in attenuating the inhibitory effect of these compounds on PDE-II was most dramatic with CI-930, milrinone, amrinone, buquineran and UK35,493 and least dramatic with carbazeran and IBMX.(ABSTRACT TRUNCATED AT 400 WORDS)

3',5'-Cyclic-AMP Phosphodiesterases↗

First impressions: paradigms for patient assessment.

The interview that the nurse completes with a patient on his admission to hospital may be seen as one more negotiated step within a patient career that may span many years. Nevertheless, the nurse's assessment of the patient marks a key point in this career, his entry into a formal institution. It also marks the starting point of a planned intervention on the part of the nurses involved. Whilst such interviews have traditionally not been seen as important as that with the consultant, they are likely to have a significant effect upon how patient and nurse subsequently interact. This paper describes a research project which sought to identify the ways in which student nurses formulate an assessment of a patient on admission. A qualitative research methodology was used and a symbolic interactionist perspective employed.

Adult↗

The clinical value of free phenytoin levels.

The relationship between total and free phenytoin levels and drug toxicity was studied in 80 patients. Twenty-four were taking phenytoin alone. Drug toxicity was assessed by a "blind" rater using an eight-point standardized scoring system. The mean free phenytoin fraction was 0.076 in patients taking phenytoin alone or phenytoin and carbamazepine and 0.11 in patients taking valproic acid (p less than 0.001). The free fraction did not change with the total level over the range tested (6.7 to 39.9 micrograms/ml total phenytoin). There was a strong correlation between free and total levels (r = 0.84). Both free (r = 0.59) and total (r = 0.49) phenytoin levels were positively correlated with the toxicity score. Only total phenytoin levels showed a weak positive correlation with decreasing seizure frequency. Our results suggest that routine free phenytoin level monitoring is not necessary in most clinical situations.

Adolescent↗

The effects of vagal nerve stimulation on endoluminal release of serotonin and substance P into the feline small intestine.

Endoluminal release of serotonin (5-HT), substance P (SP), and motilin was quantitated after thoracic vagal nerve stimulation in the cat. In duodenum and jejunum, simultaneous release of these compounds was observed. In contrast, vagal stimulation did not augment the rate of luminal secretion of either 5-HT or SP in the distal ileum. Immunohistochemical studies demonstrated 5-HT in both enterochromaffin (EC) cells and nerves throughout the small bowel. However, we were unable to visualize any SP-containing EC cells in the cat, which suggests that the source of luminal SP in this species must be intramural nerves.

Animals↗