Optic disc oval ness,refractive error and axial length of Hong Kong Chinese

Myopic crescent, refractive error and axial length were previously investigated in Hong Kong Chinese subjects. The myopic crescent was found to correlate with axial length and myopic refraction. In this study, three groups of Hong Kong Chinese with different degrees of myopia were assessed for optic disc ovalness, refractive error and axial length. The axial length was significantly correlated with the degree of myopia, indicating that the myopia was axial in nature. The regression line shows that 0.44 mm of axial elongation would give about one dioptre of increase in myopia. The elliptical ratio of the optic disc was defined as the maximal disc diameter divided by the minimal disc diameter. All three groups showed an oval disc with vertical axis greater and an increased ovalness for the high myopic group with an elliptical ratio from 1.11 in low myopia to 1.29 in high myopia. There is a small amount (about four degrees) of temporal rotation of this vertical oval orientation, which is independent of the amount of myopia. This result shows an association between axial elongation of the globe and optic disc ovalness, in addition to the previously described temporal myopic crescent. Therefore, in myopic subjects, a vertically oval disc may be associated with a myopic refraction rather than glaucoma.     

乳酸中毒和pH对狗肺血管张力和气体交换功能影响的实验研究

急性代谢性酸中毒对狗血管张力和气体交换功能的影响进行了研究。当滴入乳酸或盐酸造成急性代谢性酸中毒（ｐＨ７．００）时，可引起肺血管收缩，肺动脉压力明显升高，血氧饱和度下降，并且乳酸和盐酸引起的酸中毒对肺动脉平均压影响程度相似，提示肺血管收缩和肺动脉压升高的程度与血中ｐＨ值下降关系密切，而与此时血中乳酸水平的高低无关。     

A histologically visible representation of the fingers and palm in primate area 3b and its immutability following long-term deafferentations

An isomorph of the glabrous hand is visible in primary somato-sensory cortex (area 3b) of owl monkeys in brain sections cut parallel to the surface and stained for myelin. A mediolateral row of five ovals, separated by myelin-light septa, represents digits and corresponds precisely with cortical sites activated by light touch on individual digits in microelectrode recordings. A number of caudal ovals relate to pads of the palm. A more distinct septum separates the hand from the more lateral face representation. Within the face representation, two large myelin-dense ovals can be identified that are activated by the upper or lower face in a caudo-rostral sequence. Accidental finger loss or dorsal column section, deafferentations that result in reorganization of the physiological map in area 3b, do not alter the morphological map. The proportions for each digit and palm in the morphological map do not vary across normal and deafferented animals. Similar isomorphs were also seen in area 3b of squirrel and macaque monkeys. We conclude that the anatomical isomorph for the body surface representation in area 3b is a reliable reflection of normal cortical organization and may be a common feature of the primate area 3b. The isomorph can provide a reference in studies of somatotopic reorganization.      

Continuous wave Doppler echocardiography after surgical repair of coarctation of the aorta

Objective—To find how closely pressure gradients across the aortic arch derived from Doppler echocardiography reflect gradients measured by catheter after surgical repair of coarctation of the aorta.Design—Pressure drop across the aortic arch was measured simultaneously by continuous wave Doppler and double lumen catheter in 20 patients with repaired coarctation of the aorta.Results—The peak pressure drop estimated by Doppler was almost invariably higher than the peak to peak gradient measured by catheter, as might be expected. Wide variation was seen between the Doppler measured pressure drop and instantaneous peak gradient measured by catheter, ranging from +22 to −17 mm Hg. The reasons for these differences are unclear but are probably related to a combination of complex flow dynamics in the aortic arch, difficulty in closely aligning the Doppler beam with flow, and inability to measure flow velocity immediately proximal to the site of the surgical repair with continuous wave Doppler.Conclusions—Continuous wave Doppler echocardiography may significantly overestimate or underestimate the pressure drop after repair of coarctation and it should be interpreted with caution in individual patients. Catheterisation with angiography remains the reference standard for assessment of surgical repair of the aortic arch.     

A breast cancer cell microarray (CMA) as a rapid method to characterize candidate biomarkers

Tissue microarrays (TMAs) have become an invaluable tool in cancer research to evaluate expression and subcellular localization of proteins in cells and tissues. As the catalogs of candidate biomarkers and therapeutic targets become more extensive, there is a need to characterize and validate these targets and biomarkers in cell lines as a primary biological system in research laboratories. Thus, cell microarrays (CMAs) are useful as a high-throughput screening tool. Here, we constructed a CMA containing 32 publicly available immortalized breast cell lines with the goal of creating a method to rapidly screen for antigens of interest in breast cancer research in a relatively easy, rapid and cost-effective manner. As proof of concept, we performed immunocytochemical staining of the HER2 receptor, as the status of this protein is relevant to breast cancer and has previously been reported for these cell lines. We observed a complete concordance of our staining with the published status of HER2 in these cell lines. In addition, we examined the expression of CD44, epithelial markers EpCAM and E-cadherin and tyrosine phosphoproteins. The labeling of these proteins correlates with the known biology of the cell lines. Our results demonstrate the utility of our method to screen for potential biomarkers and therapeutic targets in breast cancer and we suggest that CMAs be used as a general approach in breast cancer research.     

Working with capacity limitations: operations management in critical care

As your hospital's ICU director, you are approached by the hospital's administration to help solve ongoing problems with ICU bed availability. The ICU seems to be constantly full, and trauma patients in the emergency department sometimes wait up to 24 hours before receiving a bed. Additionally, the cardiac surgeons were forced to cancel several elective coronary-artery bypass graft cases because there was not a bed available for postoperative recovery. The hospital administrators ask whether you can decrease your ICU length of stay, and wonder whether they should expand the ICU to include more beds For help in understanding and optimizing your ICU's throughput, you seek out the operations management researchers at your university.