Expression of blood group antigens on red cell microvesicles

The purpose of this study was to determine whether epitopes of the A, B, D, Fya, M, N, S, s, and K blood group antigens are present on microvesicle membranes shed by red cells during storage. Vesicles were isolated from outdated units of blood having and lacking the specified antigens. Diluted antisera were absorbed with fixed quantities of vesicles from red cells with the test antigen and red cells lacking that antigen (controls). The adsorbed and unadsorbed antisera were titrated and scored by using panel cells from persons known to be heterozygous for all the non-AB antigens. The mean titration scores following adsorption with the vesicles from A, B, D, M+N-, M-N+, S+s-, S-s+, and Fy(a+b-) units were appreciably lower than the control scores (0, 0, 3, 2, 2, 0, 4, and 4 vs. 19, 23, 34, 13, 12, 16, 18, and 29, respectively), which indicated the presence of these epitopes on the membrane of shed vesicles. The results following adsorption with K:1,2 vesicles were equivocal.     

PARATHYROID HORMONE-RELATED PROTEIN IN LOWER VERTEBRATES

1. Parathyroid hormone-related protein (PTHrP) is an important mediator of humoral hypercalcaemia of malignancy in humans. Normal human subjects have very low levels of PTHrP in their circulation. 2. Parathyroid hormone-related protein has recently been demonstrated in high levels in the circulation and tissues of the sea bream and the dogfish, leading to the hypothesis that PTHrP may be a ‘classical’ hormone in fish. 3. Immunohistochemistry and in situ hybridization were performed to investigate the evolutionary history of PTHrP. Tissues were examined from a number of lower vertebrates, including lungfish, lamprey and several species of bony and cartilaginous fish. Parathyroid hormone-related protein was localized to the skin and to kidney tubules in all animals studied. In the developing lungfish, PTHrP was observed in the notochord, developing brain and skeletal muscle layers. These results suggest that PTHrP is of ancient origin and has a basic and fundamental function in vertebrates.     

Noncompliance may render migraine prophylaxis useless, but once-daily regimens are better

Medicines work better if taken, which must be true of migraine prophylaxis. There is evidence that compliance with regular medication can be badly deficient. To assess how serious the problem might be in routine migraine management, we undertook a covert observational 2-month survey in a specialist headache clinic using objective measures of compliance. Subjects were 38 patients needing prophylaxis with medication prescribed once (od), twice (bd), or three times daily (tds). Medication was dispensed, unknown to them, in Medication Event Monitoring Systems (MEMS) to record openings in real time. Number, timing, and pattern of actual openings were compared with what was expected. Compliance rates averaged 66%, although returned pill counts indicated 91%. A substantial and significant difference was shown between od and bd or tds regimens. Measures of dosing interval—used-on-schedule rate and therapeutic coverage—averaged between 44% and 71%. Once-daily treatment was associated with a used-on-schedule rate more than double those of multiple daily dosing, but still only 66%. We conclude that routine use of drug prophylaxis in migraine may be so seriously undermined by poor compliance that it has little chance of efficacy. Returned-pill counting is inadequate for compliance assessment.     

长梗绞股蓝的化学成分研究

自长梗绞股蓝( Gynostemma longipes C.Y.Wu )的地上部分分得一个新的三萜皂甙,经化学方法和光谱分析确定其化学结构为19-氧化-3β,20(S),21-三羟基达玛烷-24-烯-3-O-｛[α-L-吡喃鼠李糖基(1→2)][β-D-吡喃木糖基(1→3)]｝α-L-阿拉伯糖甙,命名为长梗绞股蓝皂甙I(gylongiposideI)。     

Intracranial circulation: preliminary clinical results with three- dimensional (volume) MR angiography

The authors assessed the clinical utility of a magnetic resonance angiography technique in the evaluation of intracranial circulation. Eighteen patients with a low likelihood of cerebrovascular disease (control group) and 40 patients with suspected cerebrovascular disease were imaged with a FISP (fast imaging with steady precession) sequence (repetition time of 50 msec, echo time of 15 msec, velocity compensation in the read and section-select directions with acceleration compensation in the read direction, 15 degrees anisotropic volume, and a 1.25-mm partition thickness). Ninety-four percent of images in the control group and 72% of images in the group with cerebrovascular disease were considered useful for diagnosis. This technique can provide accurate images of intracranial circulation and can be performed in conjunction with two-dimensional spin-echo or gradient-echo imaging. It was most useful in the evaluation of patent intracranial aneurysms, vessel displacement, and large-vessel occlusive disease. Disadvantages included limited field of view, persistent signal voids, limited spatial resolution, and inadequate depiction of lesions with slow flow.     

Carotid bifurcation: MR imaging. Work in progress

To devise and implement an in-plane magnetic resonance angiography examination of the carotid bifurcation capable of producing high-resolution images, the authors examined 19 normal carotid arteries and 14 patients with angiographically documented disease with two flow-correction techniques: a three-gradient, velocity-refocused technique with spin-echo (SE) and gradient-echo sequences, and a four-gradient velocity- and acceleration-corrected SE technique. With use of three equal gradients in the read direction, velocity-related phase changes were minimized by placing the dephasing gradient after the 180 degree pulse and near the read gradient. Acceleration effects were minimized through the use of short echo times and cardiac gating. Both velocity- and acceleration-produced phase changes were corrected with the four-gradient scheme but at the expense of some limitations in spatial resolution. Both techniques consistently produced satisfactory images of the carotid bifurcation in healthy individuals. However, the results indicate that the present gradient-phase modulation techniques have several drawbacks, including susceptibility to patient motion, overlapping with the jugular vein, and inability to image carotid stenosis accurately due to turbulence.