双柱双pH固相萃取和毛细管气相色谱法同时快速测定血浆中酸性和碱性药物

报道了一种能同时快速测定血浆中酸性和碱性药物的固相萃取毛细管气相色谱法。在自制的并联双柱萃取装置上,两柱可在不同的pH下操作,分别提取酸性和碱性药物。通过对6类8种酸性和碱性药物的定性和定量实验表明,该法快速、灵敏。     

苯氧烷胺类化合物的合成及其抗高血压活性

前以2,6-二甲基苯氧乙叉为母体合成了一系列化合物,其中1-(2,6-二甲基苯氧基-2-(3,4-二甲氧基苯乙胺)-丙烷盐酸盐(Ⅰ)有较强而特久的降压作用。进一步研究又表明它具有阻断α-肾上腺素受体并兼有钙拮抗作用。     

Effectiveness of individualized neurodevelopmental care in the newborn intensive care unit (NICU)

The individual infant's neurodevelopmental process provides an integrative framework for the delivery of medical care needed to assure the infant's survival and quality of outcome. The infant's neurobehavioral functioning and expression provides an opportunity for caregivers to estimate the individual infant's current strengths, vulnerabilities and threshold to disorganization, as well as to identify the infant's strategies in collaborating in his or her best progression. This perspective supports caregivers in seeing themselves in a relationship with the infant, and in considering opportunities to enhance the infant's strengths and reduce apparent stressors in collaboration with the infant and the family. The results of several randomized studies supporting the effectiveness of such a neuro developmental approach to NICU care will be presented, and suggest implications for staff education and nursery-wide implementation.     

Increased rf power absorption in MR imaging due to rf coupling between body coil and surface coil

Fears have been voiced that excessive tissue heating could occur in the event that first, a surface coil is placed with its axis parallel to the transmitting rf field leading to a maximal coupling of the two coils and second, the decoupling circuit of the surface coil breaks down. To avoid an rf coupling of the transmitting body coil to the receive-only surface coil, conventionally applied surface coils are equipped with an active electronic rf decoupling circuit. In extensive worst-case experiments on phantoms we have shown that no tissue heating occurs for surface coils which are equipped with semiconductor varicap diodes for tuning and matching. These coils should be safe for patient applications even if the decoupling circuit fails. Surface coils equipped with mechanically variable capacitors are generally passively decoupled. To simulate the worst-case situation phantom experiments were performed in which a surface coil of this type having no passive decoupling circuit was coupled to the transmitter coil by its geometric position. Theoretical calculations, in agreement with the experimental results achieved during a 15-min measurement in a 1.5-T MRI whole-body imager, show that a significant rf power deposition in the tissue underneath the coil wire occurs, leading typically to a local specific absorption rate of 24 W/kg and a local temperature rise of 5.2 degrees C.     

Time course of the development of enzymes involved in the synthesis of norepinephrine in the superior cervical ganglion of the rat from birth to adult life

The general growth of the rat superior cervical ganglion and the development of enzymes specific for its preganglionic cholinergic and postganglionic adrenergic neurons have been studied from birth to 75 days of age. The total protein content, taken as a measure of general growth, increased 2.5-fold from birth to adulthood and approached its maximum at 20 days of age. The increase in the activity of choline acetyltransferase, which is selectively located in preganglionic cholinergic nerves and which is biochemical correlate for the formation of synapses, amounted to 50-fold for total and to 15-fold for specific activity. The maximum was reached at 30 days of age.

The increase in the activity of the enzymes characteristics of the adrenergic neurons was much smaller. The maximal increase in the specific activity of tyrosine hydroxylase amounted to only 40% and was already reached 10–14 days after birth. The specific activity of dopamine β-hydroxylase increased 2.5-fold, but the maximum was not reached before 40 days of age. The activity of DOPA decar☐ylase, the third enzymes involved in the synthesis of norepinephrine, increased virtually in parallel with the general growth of the ganglia.

The importance of the nerve growth factor and the activity of preganglionic nerves for the normal development of postganglionic adrenergic neurons are discussed in connection with previous studies which showed that both nerve growth factor in new-born rats and increased preganglionic activity in adult rats produce a selective induction of tyrosine hydroxylase and dopamine β-hydroxylase in adrenergic neurons.     

Urinary chromium excretion, diurnal changes, and relationship to creatinine excretion in healthy and sick individuals of different ages.

Since urine is the main excretory pathway for chromium, this study was conducted to compare in normal individuals the daily urinary chromium excretion with a 4 hr sample, to investigate diurnal fluctuations of urinary chromium and age-dependent relationship between urinary chromium and creatinine excretion. The results can be summarized as 1) there was no significant difference between the observed 24 hr chromium excretion and 24 hr excretion calculated from the one 4 hr samples, 2) a diurnal variation was observed when urinary excretion was expressed as chromium per minute, but no time-related variation could be established when chromium/creatinine (Cr/Cre) ratios in samples from three different periods of the same day were compared, although a significant positive correlation existed between urinary chromium and creatinine concentration, 3) the Cr/Cre ratio was found to be age-dependent, 4) in malnourished children the Cr/Cre ratio was very high and significantly different from that of normal infants, 5) This ratio for the eight diabetics was found to be significantly higher when compared with normal adults. On the basis of these results, it is suggested that morning 4 hr urinary chromium reflects the daily chromium excretion and that the Cr/Cre ratio of single urine samples obtained during this period is a reliable criterion in the evaluation of chromium nutrition of individuals in different conditions, provided that the influence of age is taken into consideration.     

Treatment with (90)Y- and (177)Lu-DOTATOC in patients with metastatic neuroendocrine tumors

BACKGROUND: Treatment with (90)Y- or (177)Lu-DOTATOC has recently been introduced in the palliative treatment of somatostatin receptor-expressing neuroendocrine tumors (NETs). The aim of the study was to present clinical experience with (90)Y- and (177)Lu-DOTATOC therapy in the management of NET. METHODS: To prove suitability for treatment each patient underwent scanning with (111)In-DTPAOC or (68)Ga-DOTATOC positron emission tomography/computed tomography. All patients received [(90)Y-DOTATOC] as initial treatment. In case of disease relapse the treatment was repeated. To avoid side effects of repeated [(90)Y] applications, a switch to [(177)Lu-DOTATOC] was carried out. Clinical, biochemical, and radioimaging responses were documented. RESULTS: Twenty patients with metastatic nonresectable NETs (15 pancreas NETs, 2 midgut NETs, 1 gastrinoma, 1 paraganglioma, 1 NET of unknown primary origin) were included. In 8 patients the treatment was repeated more than once (mean, 3 times; range, 2-5 times). After [(90)Y] treatment moderate toxicity was observed in 8 patients. No serious adverse events were documentable. After restaging, a partial remission was found in 5 patients, stable disease in 11 patients, and tumor progression in 4 patients. CONCLUSIONS: Peptide receptor-targeted radionuclide therapy is a promising, safe, and feasible approach in the palliative therapy of patients with NET.     

Increase of striatal dopamine turnover by drugs: Interference with granular storage or receptor blockade?

Apomorphine completely antagonized the reserpine-induced enhancement of the striatal 3,4-dihydroxyphenylalalinine (dopa) accumulation seen after administration of the decarboxylase inhibitor 3-hydroxybenzyl-hydrazine (NSD 1015). Reserpine-like drugs, e.g. Ro 4-1284 and Ro 4-9040, markedly enhanced the striatal dopa accumulation (due to NSD 1015) in normal animals but not in rats treated with reserpine plus apomorphine. Haleoperidol enhanced the striatal dopa accumulation to a similar extent in normal and in reserpine-apomorphine-treated animals. Chlorpromazine also caused an enhancement of striatal dopa accumulation in both types of animals, but its potency was somewhat higher in normal rats than in those treated with reserpine plus apomorphine. In conclusion, reserpinized animals treated with apomorphine appear to be useful models for differentiating whether a drug enhances striatal DA turnover by interference with granular DA storage or by blockade of DA receptors. The latter seems to be the main mechanism of action of neuroletpic drugs.