Regional left ventricular wall movement in hypertrophic cardiomyopathy.

Left ventriculograms of 20 patients with hypertrophic cardiomyopathy were digitised frame by frame and analysed using a contour display. Abnormalities of regional wall movement were present in 17, and included an abnormal sequence of inward movement during systole (13), regional delay in the onset of inward movement (10), and an abnormal dispersion of peak velocities (5). Diastolic wall movement was disturbed in 13, because of abnormal peak velocities in 7 and regional asynchrony in 6. Abnormal wall movement during the two isovolumic periods was rare in hypertrophic cardiomyopathy, unlike ischaemic heart disease. These disturbances may reflect underlying structural abnormalities.     

First pass uptake of 14C-propranolol by the lung.

Uptake of 14C-propranolol by the lungs during a single passage through the pulmonary circulation was measured in ten patients at cardiac catheterisation. Mean lung uptake of propranolol was 75% in seven patients who were not previously taking the drug and 33% in three patients who were taking it as regular oral treatment. Lung uptake of propranolol in man is therefore considerable and is partly saturable by normal oral doses. This may alter the dose response relation for propranolol and a wide range of other drugs when given intravenously. The method used to study lung uptake is simple and might be suitable for studies of endothelial cell function in disease.     

A prospective study of a serum-pooling strategy in screening blood donors for antibody to hepatitis C virus

BACKGROUND: To examine the feasibility and to perform a cost-benefit analysis of a pooling protocol of enzyme immunoassay (EIA) screening for antibody to hepatitis C virus (anti-HCV) under real conditions, a prospective study was carried out using sera from 1875 local blood donors. STUDY DESIGN AND METHODS: In the absence of knowledge of the anti-HCV reactions, the donor's sera were pooled into groups of five consecutive samples for testing by EIA. The dilution and final volume of the serum pool were adjusted to equal those recommended for single- serum EIA by the manufacturer of the test kit. The results obtained were compared with those of single-serum EIA to assess the feasibility of the pooling protocol. By applying probability theory, the percentage of reduction in the number of tests performed (L value) when the serum- pooling strategy was used was calculated for several anti-HCV seroprevalences and for varied sizes of pool. The calculations were performed on a computer using a program compiled by the authors. RESULTS: The results showed that seroprevalence was 2.24 percent (95% CI, 1.57-2.91%); the rate of false negativity was 0 (95% CI, 0–8.4%), the sensitivity of the pooling protocol was 100 percent (95% CI, 91.6- 100.0%), the rate of false positivity was 0.8 percent (95% CI, 0–1.8%), and the specificity of the pooling protocol was 99.2 percent (95% CI, 98.2-100.0%). Cost-benefit analysis showed that the pooling protocol could save 69.3 percent of the cost. A table of L values can be used conveniently by serologists to determine the optimum pool size if estimates of seroprevalence are available. CONCLUSION: The pool EIA did not perform worse than individual EIAs, and the pooling strategy was markedly less expansive. The pooling protocol was recommended for screening of anti-HCV-positive subjects from large populations with low seroprevalence.     

粘叶莸新二萜——粘叶莸酸的化学结构

从粘叶莸(Caryopteris glutinosa Rehd)地上部分的乙醚萃取物中分得一新二萜酸——粘叶莸酸(glutinic acid),其结构经IR,UV,MS,H¹-NMR,¹³C-NMR,DEPT和¹³C-¹H COSY分析确定。     

Delayed pneumothorax after CT-guided percutaneous fine needle aspiration lung biopsy

Two patients are described who developed pneumothoraces more than 24 hours after computed tomography (CT) guided percutaneous fine needle aspiration lung biopsies. The pneumothoraces required treatment in both cases. Such delayed pneumothorax after lung biopsy is extremely unusual. Patients should be warned of the possible occurrence of this complication and instructed to seek medical help if they develop chest pain or breathlessness.


     

Illustrative cases in pericardial effusion misdetection: Correlation of echocardiography and CT

Eight equivocal two-dimensional echocardiograms with concurrent CT scans were evaluated to identify potential pitfalls in pericardial effusion detection. By echocardiography, two pleural effusions were felt to be pericardial, two hemopericardiums were interpreted as normal myocardium, three loculated pericardial effusions were not seen or were misinterpreted as other mediastinal collections, and one epicardial lipoma was called a pericardial effusion. When the clinical suspicion for pericardial effusion does not correlate with echocardiographic findings, CT scanning may be the definitive arbiter of pericardial disease.     

用NOE差谱和二维核磁共振技术研究3S-取代烷氧基-奎宁环烷的立体化学

用3S-奎宁环醇与环氧化合物反应,得到化合物(Ⅰ)的二个光学异构体(3S-1)和(3S-2)。它们的生物活性有明显差别。本文采用NOE差谱和二维NMR技术指定了各异构体的^{1H和13C信号的归属,确定了它们的溶液态构象,测定了其C-11的绝对构型,并且阐明了立体结构与生物活性间的关系。C-11绝对构型的测定结果经X-射线衍射测定进一步得以肯定。}     

The straight and narrow path to good head and spine MRI

The path to good head and spine images is narrow and treacherous. We have attempted to give the traveller a small but important set of basic rules, enabling him to cross with success. 1. Averaging can be used to achieve sufficient SNR for thin sections, but the cost in terms of scan time is high. Zooming the image (reducing the field of view) should generally be avoided, as the price in terms of SNR is very high. 2. Rectangular pixels and half-Fourier imaging are two methods for decreasing scan time. HFI, which produces high spatial resolution images, can be used when the SNR is not a limiting factor. Rectangular pixels improve the SNR, but decrease resolution. 3. To achieve good T1 contrast with spin echo imaging, set TE less than or equal to 20 msec. and TR less than or equal to 600 msec. For T2 weighted images, a TR between 2.0 and 3.0 sec. is preferred, typically with two echoes: for example, TEs of 25 and 90 msec. 4. Better slice profiles or gaps between slices can be used to combat slice-to-slice interference. This results in improved SNR on T1 weighted images and improved contrast on T2 weighted images. 5. Low bandwidth techniques may be used to improve the SNR on both T1 and T2 weighted images. Chemical shift artifact puts a finite limit on the extent to which this can be applied. 6. Motion compensating gradients are a tremendous boon to MRI and should be utilized in all possible head and spine applications. These reduce image degradation from CSF and vessel pulsation, as well as from involuntary motion. 7. Fast imaging techniques can be used in 2-D multislice mode to decrease scan time. Unfortunately the T2 contrast with this approach is far inferior to that of spin echo technique. 3-D FLASH, with 1 mm. sections, T1 contrast superior to spin echo technique, and the potential for high resolution reformatted images, may replace conventional 2-D, T1 weighted, spin echo imaging. Pulse techniques that combine all the advantages mentioned lie in the future. For example, one possible approach is a T2 weighted head screen that incorporates low bandwidth technique and HFI. This would produce high resolution images with reasonable SNR in approximately half the present scan time. Despite any further new developments, the trade-off between image quality and scan time will likely always remain.(ABSTRACT TRUNCATED AT 400 WORDS)