Translocation t(6;14) as the Sole Chromosomal Abnormality in Adenoid Cystic Carcinoma of the Base of Tongue

We present an adenoid cystic carcinoma of the base of tongue in a 48-year-old male with a restricted chromosomal alteration by cytogenetic and spectral karyotypic analysis (SKY). SKY and G-banding analyses identified the t(6;14)(q25;q13) as the sole structural aberration in all metaphases analyzed. This finding supports a critical role for this event in the development of this tumor. The implications of chromosome 6q translocation in this case and in previously reported adenoid cystic carcinomas are highlighted and discussed.     

Image size magnification and power and dilation factors for optical instruments in general

Traditional treatments of spectacle magnification for distant objects consider only stigmatic spectacle lenses and they compare the retinal image size in a refractively fully compensated eye with the image size in the uncompensated eye. Spectacle magnification is expressed as a product of two factors, the power and shape factors of the lens. The power factor depends on the position of the entrance pupil of the eye. For an eye with an astigmatic cornea, however, the position of the entrance pupil is not well defined. Thus, the traditional approach to spectacle magnification does not generalize properly to allow for astigmatism. Within the constraints of linear optics and subject to the restriction that the eye's iris remains the aperture stop, this paper provides a complete, unified and exact treatment for optical instruments in general. It compares retinal image size in a generalized sense (including image shape and orientation) for any instrument in front of an eye with that of the eye alone irrespective of whether the instrument compensates or not. The approach does not make use of the concept of the entrance pupil at all and it allows for astigmatism and for non-alignment of refracting elements in the instrument and in the eye. The concept of spectacle magnification generalizes to the concept of instrument size magnification. Instrument size magnification can be expressed as the product of two matrix factors one of which can be interpreted as a power factor (as back-vertex power) and the other factor for which the name dilation factor is more appropriate in general. The general treatment is then applied to a number of special cases including afocal instruments, spectacle lenses (including obliquely crossing thick bitoric lenses), contact lenses, stigmatic systems and stigmatic eyes. In the case of spectacle lenses, the dilation factor reduces to the usual shape factor.     

Proximity factor in image size magnification for optical instruments in general

A general expression is derived for the proximity factor in near image size magnification for an arbitrary instrument in front of an arbitrary eye. The proximity factor is a 2 x 2 matrix. The instrument and eye may be astigmatic and have decentred elements. The image on the retina may be blurred or not. The analysis is exact within the limitations of linear optics. The general results are specialized for the case of a stigmatic instrument and a stigmatic eye. The results are applied to the case of a thick, possibly bitoric, spectacle lens. The Appendix treats two numerical examples.     

Force-time parameters during explosive isometric grip correlate with muscle power

Although explosive isometric contraction provides little work toward the outside, force-time parameters of the rising phase of the force-time curve may be able to predict muscle power. The purpose of this study was to examine the relationship between muscle power with work (power grip) and force-time parameters during the rising phase in explosive isometric grip. Fifteen healthy young adult males participated in this study. Power grip was measured using loads of 20%–50% of maximal voluntary contraction (MVC) (peak isometric force). Subjects pulled explosively on a grip bar held with the second digital joints without the thumb. Peak power was calculated from peak velocity and load. Explosive isometric grip was measured using a hand dynamometer. Time-series data of both tests were sampled by an analog-to-digital interface. Both tests were performed with the subjects seated with a sagittal and horizontal position of the arm supported by an armrest. Peak power in the power grip test tended to be larger with an increase of the load, but there was no significant difference between 40% and 50% MVC. Only the peak power in 50% MVC significantly correlated with peak grip force (r=0.52, p<0.05). The force-time parameters related to the peak rate of the rising force phase in explosive isometric grip significantly correlated with the peak powers (30%–50% MVC, r=|0.58−0.78|). Peak rate of the rising force phase in explosive isometric grip may be useful for predicting muscle power with loads between 30%–50% MVC.     

多层螺旋CT对冠状动脉粥样硬化斑块的显示结果及与超声结果的比较

目的评价多层螺旋CT（MSCT）探查无明显管腔狭窄的冠状动脉粥样硬化斑块的能力及准确性。方法共35例连续患者行冠状动脉内超声（IVUS）及16层MSCT检查，其中30例MSCT成像成功。对94支无明显狭窄的冠状动脉节段MSCT及IVUS图像行对照研究，逐一分析每支冠状动脉节段是否出现粥样硬化斑块。IVUS根据斑块回声特点将斑块分为钙化斑块、纤维斑块和软斑块，MSCT则测量斑块密度，以CT值表示。结果对照IVUS结果，MSCT对出现任何粥样硬化斑块节段的诊断敏感性为82．1％（46／56），特异性为89．5％（34／38）。对于含钙化斑块的节段，MSCT诊断敏感性为92．1％（35／38），特异性为96．4％（54／56）。对于含非钙化斑块的节段，MSCT诊断敏感性为73．2％（30／41），特异性为88．7％（47／53）。对于仅含非钙化斑块的节段，MSCT诊断敏感性为66．7％（12／18）。MSCT分析54个斑块平均CT值，按照IVUS分类，钙化斑块19个，纤维斑块19个，软斑块16个，对应CT值分别为：钙化斑块（489±169）HU（196～817HU），纤维斑块（69±21）HU（25～117HU）以及软斑块（23±18）HU（-12～47HU）。非参数Kruskal-Wallis检验显示3组斑块MSCT测量密度CT值间差异有统计学意义（P值均〈0．01）；两种方法对斑块面积的测量具有相关性（r=0．58，P〈0．01），MSCT测定斑块平均面积为5．3mm^2，IVUS为5．6mm^2。结论MSCT对无明显管腔狭窄的冠状动脉粥样硬化斑块有良好的探查能力。根据斑块密度（CT值）差异，MSCT能区分不同类型冠状动脉粥样斑块。对斑块面积测量，MSCT与IVUS结果具有相关性。     

NEWLY DEVELOPED ULTRASOUND ENDOSCOPE WITH AN ELECTRONIC RADIAL ARRAY TRANSDUCER

A prototype electronic radial scan ultrasound endoscope has been developed by Olympus (Tokyo, Japan) for endoscopic ultrasound (EUS) study. The ultrasound view‐angle of this model is 360° vertical to the scope. Though the diameter of the scanner and the shaft of the scope is bigger than those of the present mechanical radial scan model, clinical manipulation of the new scope is the same as that of the present model. Image quality of the ultrasound picture demonstrated by the electronic radial model was as clear as those provided by the mechanical radial scan model. Ultrasound penetration was better and satisfactory because of less echoic reduction compared to the mechanical radial model. The newly developed electronic radial model can be evaluated as an ultrasound endoscope for the next generation. The advantage of this system is to facilitate the clinical use of color Doppler function and tissue harmonic imaging, and this system can be operated by the same monitor unit as a convex model of ultrasound endoscope.     

Health policy, epidemiology and power: the interest web

The relation between epidemiological research results and policy-making is reviewed. Apparently, traditional models of policy-making(incrementalism, mixed scanning synoptic planning) do not explainwhy research findings are hardly used in policy-making procedures. It is suggested that this phenomenon is related to three determinantsof policy-making: (i) a bias stemming from sets of causal, finaland normative assumptions and presuppositions; (ii) interestwebs of groups in certain domains; and (iii) the power of organizationsto monitor and communicate. The conclusion is that epidemiologistsshould engage in the policy-making process more consciouslyand conscientiously.     

Heart failure: Effects of beta receptor antagonists on left ventricular function in patients with clinical evidence of heart failure after myocardial infarction. A double-blind comparison of metoprolol and xamoterol Echocardiographic results from the Metoprolol and Xamoterol Infarction Study (MEXIS)

Two hundred and ten patients with clinical evidence of heartfailure, developing after an acute myocardial infarction, wererandomized to treatment with the ß₁ antagonist metoprolol50–100mg b.i.d. (n=106) or the ß₁ partial agonistxamoterol 100–200 mg bid. (n=104). Left ventricular systolicand diastolic function were assessed with echocardiography andtransmitral Doppler cardiography before and after 3 and 12 monthsof double-blind treatment. E-point septal separation and percent left ventricular fractional shortening were used as indicesof systolic function. The ratio between peak early and latemitral diastolic flow (E/A ratio) and isovolumic relaxationtime were used as indices of diastolic function. In the xamoterol group, there was a deterioration in E-pointseptal separation (P<0·05). A difference between thetreatment groups was present both at 3 months (E-point septalseparation 11·4 vs 13·0 mm, P<0·0l,fractional short ening 271 vs 252%, P<005) and 12 months(E-point septal separation Ill vs 13·2 mm, P<0·05fractional shortening 26·9 vs 25·0%, P<0·05).E/A ratio increased in the metoprolol group (P<0·05)but not in the xamoterol group. At 3 months there was a significantdifference (0·85 vs 0·67, P<0·005 betweenthe groups but not at 12 months. In comparison with the ß₁-receptor antagonist metoprolol,the ß₁ partial agonist xamoterol impaired left ventricularsystolic function in patients with clinical evidence of heartfailure after an acute myocardial infarction.     

Developmental changes in intracellular pH buffering power in smooth muscle

 Intracellular pH (pH_i) is known to modulate contraction. Neonatal tissues can differ from adult tissue in contractile response to stimuli known to alter pH_i e.g. hypoxia. Changes of pH are attenuated by buffering, thus any difference in buffering power (β) between tissues could affect their functional response to pH_i perturbation. Similarly the extent to which any extracellular pH (pH_o) alteration is transmitted into a pH_i change will also influence function. We have therefore determined the intrinsic β and effect of pH_o change on pH_i in neonatal and adult ureteric, uterine and gastric smooth muscles using the pH-sensitive fluorophore carboxy-SNARF. β was found to be similar in the three adult tissues, but there were significant differences between neonatal tissues. In contrast, we found little difference in the amount of pH_i change produced by pH_o change between neonatal and adult tissues from the same smooth muscle, but a difference between smooth muscles. These data highlight significant differences between smooth muscles and their developmental state, which may contribute to different degrees of protection when pH is perturbed. Received: 17 October 1997 / Received after revision: 27 November 1997 / Accepted: 28 November 1997     

Wheezing at 8 and 13 years: changing importance of bronchiolitis and passive smoking

A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses. Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood. Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P less than 0.01) and in multivariate analysis (odds ratio = 2.67, P less than 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years.