离子色谱法同时测定葡萄糖酸钙及其杂质(Cl-,SO42-)的含量

本文采用Waters ILC-1离子液相色谱仪,IC-PAK A50×4.6mm色谱柱,pH6.61×10^-3mol/L邻苯二甲酸溶液为流动相,430型电导检测器检测,由外标法和外标单点校正法同时测定了葡萄糖酸钙及其杂质(Cl^-,SO₄^2-)的含量。方法简便、快速,测定结果与中国药典法一致。外标法和外标单点校正法测定Cl^-,SO₄^2-的平均回收率为100.8%和100.2%,相关系数分别为0.9951(n=8)和0.9961(n=8)。     

Sulfhydryl reagents induce altered spectrin self-association, skeletal instability, and increased thermal sensitivity of red cells

Incubation of erythrocytes with the sulfhydryl reagent N-ethyl- maleimide (NEM) results in altered spectrin self-association and formation of dimers on the membrane. Skeletons isolated from these cells exhibit marked skeletal instability. In addition, NEM treatment induces increased thermal sensitivity of both cells and purified spectrin. These effects were not produced in aerobically incubated glucose-6-phosphate dehydrogenase deficient cells and were therefore presumably not due to depletion of intracellular reduced glutathione. These effects were produced by another permeant sulfhydryl reagent, monobromobimane, but not by its membrane-impermeant derivative. We conclude that spectrin sulfhydryl groups play an important role in spectrin self-association and thermal stability.     

Percutaneous gastrostomy in a child

A 2-year-old girl with cyanotic congenital heart disease needed to undergo gastrostomy. To avoid the use of general anesthesia, a percutaneous gastrostomy was performed as an interventional radiologic procedure with the patient under sedation and with the use of local anesthesia. The placement of a nasogastrocutaneous guide wire under fluoroscopic guidance provided a stable tract for placement of the gastrostomy tube.     

Difficulties in Immunohaematology : The Weak D Antigen

Background

The Rh blood system is one of the most polymorphic and immunogenic systems known to humans. The expression of Rh blood group antigen is complex. The Rh D antigen is the most important of the antigens that constitute the Rh antigen system. In most cases, D antigen can easily be detected. However, due to variability of expression, weak forms antigen are encountered. The reactivity of weak D with antisera is variable and presents as a problem in blood banking.

Methods

A retrospective analysis for a five-year period was done. Blood samples that were negative for Rh D by immediate spin tube method were tested for weak D antigen by additional lab tests.

Result

Of 34932 serial Rh grouping tests done in our Blood Bank, the incidence of weak D Rh antigen was 0.189%. All these were confirmed by the antiglobulin test.

Conclusion

These patients present as a problem for the blood banker and a curiosity to the clinician. Although uncommon, all health care workers should be aware of this entity to avoid anti D alloimmunisation.Key Words: Weak D, Rh Blood Group     

HUMAN RESPIRATORY MUSCLES: SENSATIONS, REFLEXES AND FATIGUABILITY

1. Given the importance of the ventilatory ‘pump’ muscles, it would not be surprising if they were endowed with both sensory and motor specializations. The present review focuses on some unexpected properties of the respiratory muscle system in human subjects. 2. Although changes in blood gas tension were long held not to influence sensation directly, studies in subjects who are completely paralysed show that increases in arterial CO₂ levels elicit strong sensations of respiratory discomfort. 3. Stretch reflexes in human limb muscles contain a monosynaptic spinal excitation and a long-latency excitation. However, inspiratory muscles show an initial inhibition when tested with brief airway occlusions during inspiration. This inhibition does not depend critically on input from pulmonary or upper airway receptors. 4. Human inspiratory muscles (including the diaphragm) have been considered to fatigue during inspiratory resistive loading. However, recent studies using phrenic nerve stimulation to test the force produced by the diaphragm show that carbon dioxide retention (hypoventilation) and voluntary cessation of loading occur before the muscles become overtly fatigued.     

Infant Flow Driver or single prong nasal continuous positive airway pressure: short-term physiological effects

The effectiveness of single prong nasal continuous positive airway pressure (CPAP) was compared with the Infant Flow Driver (IFD) in a crossover study in 20 neonates treated with ≤ 30% oxygen by nasal CPAP. They were randomized to the device used at the start of the study. Each infant was studied for four consecutive 2-h periods alternating between single prong nasal CPAP and the IFD. The FiO² from the IFD read 0.02 higher than the same setting on the ventilators used for single prong nasal CPAP. The IFD improved the mean (95% CI) of theFiO₂by 0.05 (0.02–0.08), p = 0:008. Taking into account the systematic error in the FiO² between the devices the real mean improvement in FiO₂ produced by the IFD was 0.03 (-0.005 to 0.06), p = 0:09. There were no significant differences in respiratory rate, heart rate, blood pressure or comfort score of infants during periods of single nasal prong CPAP compared with periods on the IFD.     

Respiratory distress syndrome treated with human surfactant: radiographic findings

Chest radiographs of 18 newborns treated with endotracheal instillation of human surfactant for respiratory distress syndrome (RDS) were compared with those of 18 similar but untreated infants. In the treated infants, severity of RDS significantly improved after surfactant administration. Most treated infants (16/18) exhibited a left-to-right shunt, presumably through a patent ductus arteriosus; similar findings were noted in untreated infants (17/18). Complications of respiratory assistance in the treated infants included transient pulmonary interstitial emphysema (n = 1), pneumothorax (n = 1), and mild (n = 4) to moderate (n = 2) bronchopulmonary dysplasia; the incidences of these complications did not exceed those in untreated infants. In three treated infants, a transient interstitial lung disease developed 3-4 days after surfactant administration.     

利用Pirkle型手性固定相柱拆分对映体药物:用异氰酸-α萘酯衍生化拆分烯丙洛尔等β-阻断剂药物及衍生物的结构鉴定

利用异氰酸-α萘酯(NI)作衍生化试剂,在Pirkle型DNBPG柱上拆分了β-阻断(?)丙洛尔等药物。方法简便,分离度好。对其衍生物结构的研究表明:在温和的条件下,异氰酸酯与分析物的仲氨基反应,生成脲;若反应在较强烈的条件下进行,则将发生异构化,最终是异氰酸酯与羟基结合,生成氨基甲酸酯。实验还表明,NI试剂与分析物之间的反应是按1:1进行的。