Sensitivity and specificity of left ventricular ejection fraction by echocardiographic automated border detection: Comparison with radionuclide ventriculography

Background: Echocardiographic automated border detection (ABD) provides on-line, beat-to-beat estimation of left ventricular (LV) ejection fraction (EF). Sensitivity and specificity of using ABD-EF for diagnosing LV dysfunction in routine clinical situations have not been previously studied. Hypothesis: Analysis of ABD-EF data based on receiver operating characteristic (ROC) should provide useful information about sensitivity and specificity for clinical diagnosis of LV function based on ABD-EF. Methods: The study group included 50 consecutive patients with EF measured by both ABD and radionuclide ventriculography (RVG). ABD-EF was recorded for 25 consecutive heart beats in the apical four-chamber view. Data were analyzed statistically by linear regression, Bland-Altman plot, and ROC. In ROC analysis, abnormal LV function was defined RVG-EF ≤ 40%. Results: ABD and RVG showed a moderate correlation in the EF measurements: slope=0.93, intercept=17%, r=0.79 (n = 50). Interbeat variability in ABD was diminished by averaging consecutive beats; standard error of estimate (SEE) decreased from 15.6% without averaging to 12.5% with 25-beat averaging. Bland-Altman analysis indicated that ABD-EF compared unfavorably with RVG-EF, with limits of agreement from -11% to 39%. ABD-EF showed a systematic overestimation (p<0.005), which was compensated by increasing the threshold for abnormal ABD-EF to 56%. With the optimized threshold, ABD-EF provided 89% sensitivity and 89% specificity (85% overall diagnostic accuracy) for diagnosing abnormal LV function. Conclusion: This study explored the limitations of on-line echocardiographic measurement of EF in a clinical setting and provided useful data for assessing interbeat variability, sensitivity, and specificit.     

Technique and use of transbronchial biopsy in children and adolescents.

Since July 1988, a total of 92 transbronchial biopsies (TBB) have been performed in 18 patients (aged 3-16 years). Twelve patients (67%) were heart-lung transplant (HLT) recipients undergoing surveillance for pulmonary graft rejection and infection. The remainder included immunocompromised patients at risk of opportunistic infections (n = 4), patients with fibrosing alveolitis (n = 1) and a collagen vascular disorder with suspected lung involvement (n = 1). TBB was performed through either a fiberoptic (n = 50) or a rigid (n = 41) bronchoscope, all under general anesthesia. On one occasion a cardiac bioptome was used through an endotracheal stent. The sensitivity of TBB for diagnosing acute and chronic rejection in HLT patients was 88% and 60%, respectively (specificity, 91% and 100%). Definitive diagnoses were made in 4 (67%) of the non-HLT group. Bronchoalveolar lavage (BAL) was performed during each procedure for microbiological and cytological examination. Thirty-four pathogenic organisms including Pseudomonas aeruginosa (16/34), Staphylococcus aureus (8/34), and Candida albicans (5/34) were isolated from BAL culture. Complications included pneumothorax (8%), transient pyrexia (7%), and dyspnea (2%).     

The quality of mass screening for breast cancer by physical examination

Mass screening for breast cancer using physical examination alone has been carried out since 1983 in Zentsuji, Kagawa Prefecture, Japan. Over a 7-year period, breast cancer was detected in 11 of a total 8,271 examinees, the detection rate being high at 0.13%. The detected cases included a few early-staged breast cancers, suggesting that mass screenings are of slight efficacy. Seven cases of interval cancer were found by breast self-examination after the mass screenings, supporting the value of breast self-examination. A relatively large number of interval breast cancers was detected in 1985 and 1986, when the rates of required further examination remained under 1%. The sensitivity and specificity of this screening were 61.1% and 94.5%, respectively, indicating a low sensitivity. These results suggest that the qualitative diagnoses made from the first screening by physical examination alone were often revealed to be false negatives. Therefore, the existing diagnosis should be employed in the first screenings. It is recommended that mammography be introduced to detect breast tumors which are nonpalpable or undetectable by physical examination alone.     

The involvement of surface sugars of mammalian spermatozoa in epididymal maturation and in vitro sperm-zona recognition: Die Beteiligung von Oberflächen-Zuckern von Säuger-Spermatozoen auf die Nebenhodenreifung und die in vitro Spermatozoen-Zona-Erkennung

The distribution of various simple sugar residues over the spermatozoa surfaces of five different mammalian species is characterized and compared. Epididymal maturation of the spermatozoa of all the five species studied exhibited an increase in the amount of N-acetyl-D-glucosamine residues over their acrosomal domains. A complete blockade of sperm-zona pellucida attachment of hamster gametes could be brought about when spermatozoa were treated previously with 0.1 M of N-acetyl-D-glucosamine. This sugar seems to be specifically involved in sperm-zona pellucida attachment in hamsters. The inter-specific cross-reactivity of gametes of laboratory mammals like rat, mouse, rabbit and hamster could, quite likely, be because of the involvement of N-acetyl-D-glucosamine as a common factor in this reaction in these animals.     

四种方法检测HBsAg的效果比较

同时用放射免疫法(RIA)、反向间接血凝法(RPHA)、普通对流免疫电泳(CIE)及放射免疫自显影四种方法检测340份血清的HBsAg。结果表明:自显影法与CIE敏感度相近,RPHA优于前面两种方法,虽不及RIA敏感度高,但操作简便,故仍然是适用于大规模血清流行病学研究的检测方法。     

Assessment of female sexual arousal: Response specificity and construct validity

Specificity of vaginal pulse amplitude and vaginal blood volume in reaction to visual sexual stimuli was investigated by comparing responses to sexual, anxiety-inducing, sexually threatening, and neutral film excerpts. Subjective sexual arousal, body sensations, emotional experience, skin conductance, and heart rate were monitored along with the genital measures. Self-report data confirmed the generation of affective states as intended. Results demonstrated response specificity of vaginal vasocongestion to sexual stimuli. In terms of both convergent and divergent validity, vaginal pulse amplitude was the superior genital measure. Skin conductance discriminated among stimuli only to a small degree, whereas heart rate failed to discriminate among stimuli altogether.     

犬细小病毒在乳猫肾细胞内生长动态观察

本文记述了犬细小病毒在乳猫肾细胞内生长情况。试验中观察了包涵体形成的过程与细胞培养液内病毒血凝滴度的联系;用亲和素-生物素酶间接染色法证明细胞内的变化是特异的;在4℃pH7.2条件下病毒液对猪血球、猴血球、猫血球均可产生血凝现象,且对猪血球凝集效价最高,而用犬细小病毒阳性血清与病毒液作用,可抑制此血凝现象;电镜检查感染细胞,发现胞核变化较明显,将感染细胞培养液作免疫电镜检查,可见聚集的细小病毒颗粒。     

Phencyclidine (PCP)-like discriminative stimulus effects of metaphit and of 2-amino-5-phosphonovalerate in pigeons: generality across different training doses of PCP

Pigeons were trained to discriminate either a fixed dose of PCP (1 mg/kg; n=3) or a progressively decreasing dose (1-0.56–0.32 mg/kg; n=4) from saline. Lowering of the training dose shifted the dose-effect curve for PCP's discriminative stimulus effects about 5-fold to the left, in a parallel manner, but did not decrease the accuracy of the discrimination performance and did not significantly increase the extent to which pentobarbital and chlordiazepoxide produced PCP-appropriate responding. Dose-effect curves based on binary generalization data were evaluated statistically with new methods that may be more appropriate than those used previously. Metaphit, a proposed PCP-receptor acylator, and 2-amino-5-phosphonovalerate (AP5), an N-methyl-d-aspartate (NMDA) antagonist, produced complete PCP-appropriate responding in the high training dose group only at doses that suppressed the rate of responding and that produced ataxia. However, 4-fold lower doses of metaphit and AP5, which did not produce directly observable behavioral effects, were found to substitute completely for PCP in the low training dose group. These data support the notion that PCP, metaphit, and AP5 have a common discriminative effect in pigeons.