Ferrite particles for bowel contrast in MR imaging: design issues and feasibility studies

Diverse materials with varying physical and magnetic properties have been evaluated as gastrointestinal contrast agents for magnetic resonance (MR) imaging. Uniform marking of the small bowel remains the greatest challenge. Ferrites are magnetically active iron oxide particles that are miscible with water and cause loss of signal on MR images. The decrease in MR signal intensity produced by ferrites occurs with a wide range of iron concentrations (0.1-10 mM) and with both T1- and T2-weighted pulse sequences. These effects of ferrites are explained by predominant T2 shortening with negligible T1 effects. The ferrite preparation used in this study was stable in vitro, with little iron solubilized by acid. Intragastric administration of ferrite (5 mg of iron per kg in 6 ml) routinely marked the small bowel of rats. The authors conclude that ferrites represent a promising new class of contrast agents for gastrointestinal MR imaging.     

Tetrahydrocannabinol vs. prochlorperazine. The effects of two antiemetics on patients undergoing radiotherapy

The authors tested the effectiveness of orally administered delta-9-tetrahydrocannabinol (THC) as compared to prochlorperazine for the alleviation of symptoms, such as vomiting and nausea, experienced by patients receiving radiotherapy. The test subjects rated the severity of their illness, as well as the extent of their subsequent moods, their level of concentration, their amount of physical activity, and their desire for social interaction. They chose the drug they preferred and recorded its side effects. The use of THC was slightly more beneficial than the use of prochlorperazine.     

人参皂甙Rb1和Rg1对小鼠中枢神经递质受体和脑内蛋白质合成的影响

应用放射配基结合法测定了人参皂甙Rb₁和Rg₁对α₁,α₂,β肾上腺素能受体、M胆碱能受体、5-羟色胺、多巴胺及GABA等七种受体的作用。结果均不能证明它们对这七种受体有亲和力。但给动物ip药物连续5天,Rb₁和Rg₁均能使中枢M胆碱受体密度显著增高。Rb₁及Rg₁还能显著增加脑内蛋白质的含量。上述实验结果对解释人参的中枢作用提供了重要证据。     

Intrauterine growth retardation: evaluation by magnetic resonance. Work in progress

Eleven high risk fetuses between 32 and 37 menstrual weeks gestational age were examined by magnetic resonance (MR) imaging. Serial obstetrical sonograms, birth weights, and serial postnatal examinations were obtained in all subjects. Sagittal MR spin echo images obtained using TR = 0.5 sec and TE = 28 msec were useful for assessing subcutaneous fat. Prospective estimates of fetal fat stores correlated with neonatal outcome better than sonographic measurements of fetal growth parameters or actual birth weight. MR appears to be a safe and useful technique that offers information complementary to obstetrical sonography when IUGR is suspected.     

Circulatory changes in the sitting position during neurosurgical anaesthesia (NLA) (author's transl)

In 23 neurosurgical patients with haemodynamic effects of neuroleptanaesthesia in the supine (13 patients) and upright position (10 patients) were studied. The patients in the upright position demonstrated an increase of the mean arterial pressure of 19% and the total peripheral resistance of 45%, and simultaneously a decreased stroke index of 20% and the cardiac index of 16%. The stability of the circulation was preserved due to the increase of heart rate (to 90 +/- 17 beats/min) and total peripheral resistance. In spite of the almost identical average total dose of fentanyl in both groups (4.72 +/- 2.2 mcg/kg/h), supine position) and 4.97 +/- 2.23 mcg/kg/h, (sitting position), only the patient group in the supine position demonstrated a decrease of pulse rate of 36% to 65 +/- 20 beats/min with a decline of the cardiac index of 33% and unchanged stroke index. Our clinical observations and the animal studies of other authors allow the conclusion that during neuroleptanaesthesia in the upright position the baroreceptor-activity and the catecholamine secretion is not markedly reduced and consequently circulatory stability obtained. We regard neuroleptanaesthesia as the method of choice for neurosurgical operations in the upright position.