Computerized diagnosis: implications for clinical education

The advent of the small computer as a basic clinical tool will have a significant impact on clinical practice and medical training. The application of probability theory to clinical diagnosis has led to the development of several practical diagnostic programs which run on small computers. Expert systems--interactive programs which function as 'electronic consultants'--have now been successfully developed for a number of clinical situations. Experience with two of these, INTERNIST/CADUCEUS and MYCIN, has provided insight into problems and prospects for expert systems in medicine. Less complex programs, particularly those employing clinical prediction rules, and expert system shells, seem well suited for clinical environments. Although computerized medical diagnosis holds great promise as an aid to clinicians, its success will largely be determined by the quality of the information that clinicians provide for analysis. A brief review of the status of bedside diagnosis reveals that data-gathering strategies and techniques must be better understood. In order to take full advantage of computer programs for diagnosis, basic diagnostic skills must be more heavily emphasized in clinical training.     

喉部CT仿真内窥镜成像技术的探讨

目的：探讨喉部CT仿真内窥镜(CT virtual endoscopy，CTVE)的成像质量及其影响因素。方法：对84例喉部螺旋CT扫描者行CTVE成像，根据喉腔内部结构、病灶、黏膜皱襞的显示情况和有无伪影将CTVE图像分为3级，分别比较CTVE技术在不同的扫描层厚、重建层厚及阈值的情况下图像质量的优劣。结果：CT原始扫描层厚为2mm、3mm分别与5mm、8mm的CTVE图像质量相比较，有显著性差异(P＜0．05)；重建层厚为2mm、3mm与5mm相比较，均有显著性差异(P＜0．05)；阈值为 -800— -600HU与阈值为-300HU相比较，有显著性差异(P＜0．05)。结论：不同的CT原始扫描层厚、重建层厚及阈值对CTVE图像的质量影响有明显差异。选用合适的原始扫描参数及重建参数，可以提高CTVE图像的质量，对喉部疾病的诊断很有帮助。     

助孕技术的发展对人类生殖伦理观念的冲击

新近发展的助孕技术给众多不孕夫妇带来为人父母的喜悦之时，也对人们传统的生殖伦理观念形成冲击并挑战现存法律制度。人们不仅要肯定助孕技术的合理性，也要警惕其所产生的潜在的破坏性影响。合理利用该技术和制定相应的法规是避免出现伦理和社会混乱的有效途径。     

胚胎种植前遗传学检测助孕妊娠结局的影响因素研究

背景 育龄期女性胚胎着床失败及流产的最常见原因是胚胎异常,但移植经胚胎种植前遗传学检测(PGT)筛选后的正常胚胎后,仍出现种植失败或流产的原因目前并没有形成统一的结论。目的 分析PGT助孕后种植失败及流产的影响因素。方法 回顾性分析2018年12月至2021年2月在安徽医科大学第一附属医院生殖中心行PGT助孕的329例患者的临床资料,根据患者是否临床妊娠分为临床妊娠组(n=218)和种植失败组(n=111),并将临床妊娠组患者根据妊娠结局分为活产亚组(n=175)和流产亚组(n=43)。比较临床妊娠组和种植失败组,活产亚组和流产亚组的一般情况、促排卵及体外胚胎发育情况。采用多因素Logistic回归分析探讨PGT患者种植失败及流产的影响因素。绘制受试者工作特征(ROC)曲线分析多因素Logistic回归分析筛选出的影响因素对PGT患者发生种植失败及流产的预测价值。结果 多因素Logistic回归分析显示,既往流产次数≥2次〔OR=4.032 0,95%CI(2.423 0,6.710 0)〕、高密度脂蛋白胆固醇(HDL-C)水平低〔OR=3.890 0,95%CI(1.455 0,10...     

Single top quality embryo transfer as a model for prediction of early pregnancy outcome

BACKGROUND: Single embryo transfer (particularly of a top quality embryo) is an excellent model to correlate embryo quality in terms of morphological criteria to early pregnancy. We investigated whether this model could provide us with more information on what happens after implantation in the first trimester of pregnancy. METHODS: The outcome of 370 consecutive single top quality embryo transfers in patients younger than 38 years was analysed for pregnancy and first-trimester pregnancy loss (FTPL) before 13 weeks of gestation. Analysis was done on each cohort of embryos from which the transferred top quality embryo was selected. Serum HCG levels were measured on day 8 and day 12 after day 3 embryo transfer. The HCG index was calculated as the level of HCG on day 12/HCG on day 8. RESULTS: The pregnancy rate after single top quality embryo transfer was 51.9%. This was independent of the patients' age. FTPL, however, appeared to be age dependent: 15.4% for the whole group, 9% in patients younger than 30 years and 19% in patients above 30 years. The pregnancy rate was 50% in IVF cycles and 52% in ICSI cycles; FTPL was 19% in IVF cycles and 10% in ICSI cycles. Multiple regression analysis showed that these differences originated from age differences between both populations rather than from technique-related factors. An HCG level >or=45 IU/l on day 12 was predictive for ongoing pregnancy with 75.6% sensitivity and 100% specificity; an HCG index >or=3.5 similarly predicted ongoing pregnancy with 72.3% sensitivity and 100% specificity. CONCLUSIONS: These data show that embryo selection for transfer on day 3 can be used as an excellent tool for prediction of pregnancy but not for prediction of FTPL. The pregnancy rate of a single top quality embryo is not related to age, whereas FTPL is age dependent.     

Levothyroxine treatment in thyroid peroxidase antibody-positive women undergoing assisted reproduction technologies: a prospective study

BACKGROUND: Infertile women positive for thyroid antibodies suffer from a poor pregnancy/delivery outcome, although conflicting data have been published. Our objective was to investigate if levothyroxine (LT4) exerts any effect on pregnancy and/or delivery rates in thyroid peroxidase antibody (TPOAb)-positive (+) women undergoing assisted reproductive technologies. METHODS: Patients undergoing treatment were screened for TPOAb, thyroid-stimulating hormone (TSH) and free thyroxine (FT4). A total of 72 (15%) out of the 484 euthyroid women selected were TPOAb (+). These 72 patients were randomly divided into two groups: group A (n = 36) underwent LT4 treatment, group B (n = 36) placebo. Group C consisted of 412 women (85%) who were TPOAb negative (-). All patients received controlled ovarian stimulation. The endpoints of treatment were pregnancy rate, miscarriage rate and delivery rate. RESULTS: No differences in pregnancy rate were observed between the three groups. Miscarriage rate was higher in TPOAb (+) in comparison to TPOAb (-) [relative risk: 2.01 (95% CI = 1.13-3.56), P = 0.028]. CONCLUSIONS: The pregnancy rate is not affected either by presence of TPOAb or treatment with LT4. However, TPOAb (+) women show a poorer delivery rate compared to TPOAb (-). LT4 treatment in TPOAb (+) does not affect the delivery rate.     

The Effect of End Group Modification on the Transparency of Vinyl Addition Norbornene Polymers at 193 nm

Summary: Homopolymers of a bis‐trifluorocarbinol substituted norbornene ( 1 ) (α,α‐bis(trifluoromethyl)bicyclo[2.2.1]hept‐5‐ene‐2‐ethanol or HFANB) and copolymers of 1 with t‐butyl ester of 5‐carboxylic acid ( 2 , t‐BuEsNB) were produced using palladium catalysts and olefinic chain transfer agents such as 1‐hexene and ethylene to control molecular weight. However, these low‐molecular‐weight polymers exhibited relatively low optical transparencies at 193 nm. In fact, the opacity (measured as optical densities in absorbance units per micron) of thin films of these homo‐ and co‐polymers was inversely proportional to their molecular weight. This relationship is consistent with an end group contribution to the film opacity. Spectroscopic analysis of these polymers by ¹H NMR and MALDI‐TOF MS confirmed that 1‐hexene and ethylene chain transfer agents generated olefin‐terminated vinyl addition polymers. The olefinic end group contribution to optical density can be eliminated by appropriate chemical modification. Both epoxidation and hydrogenation of the polymer olefinic end groups generated very low optical density materials, independent of molecular weight, that are suitable as 193‐nm photoresist binder resins.

End group modification of vinyl and hexenyl‐terminated homopolymers of 1 by epoxidation or hydrogenation.     

Impact of elective single embryo transfer on the twin pregnancy rate

BACKGROUND: It is unclear how the implementation of elective single embryo transfer in clinical practice would affect clinical pregnancy and delivery rates and multiple birth rates. METHODS: This retrospective study analysed 1871 IVF/ICSI cycles carried out from 1997 to 2001 in the IVF programme of a single university infertility clinic. RESULTS: The number of elective single embryo transfers increased from 11 to 56%. At the same time the clinical pregnancy rate was relatively stable; mean 34.0% (range 28-42). The number of embryos per embryo transfer decreased from 1.8 to 1.3. The multiple pregnancy and delivery rates dropped markedly from 25 to 7.5% and from 25 to 5% respectively. CONCLUSIONS: An elective single embryo transfer programme can be adopted in daily practice that decreases the twinning rate to <10% and does not affect the overall pregnancy rate.     

IVF/ICSI outcome and serum LH concentration on day 1 of ovarian stimulation with recombinant FSH under pituitary suppression

BACKGROUND: Down-regulation with GnRH agonist has been suggested to result in a profound suppression of LH bioactivity, reduced estradiol synthesis, and thus impaired IVF and pregnancy outcome. The aims of this study were: (i) to assess the usefulness of serum LH measurement on stimulation day 1 as a predictor of ovarian response, conception and pregnancy outcome in patients treated with long-term down-regulation with GnRH agonist and recombinant FSH, and (ii) to define the best threshold LH value, if any, to discriminate between women with different outcomes of IVF. METHODS: Records of 2625 cycles in 1652 infertile women undergoing IVF (n = 1856) and/or ICSI (n = 769) treatment were reviewed. RESULTS: The range of LH concentrations on stimulation day 1 overlapped among non-conception cycles, conception cycles, ongoing pregnancies and early pregnancy losses. Receiver operating characteristic (ROC) analysis showed that serum LH concentrations on stimulation day 1 were unable to discriminate between conception and non-conception cycles (AUC(ROC) = 0.51; 95% CI: 0.49-0.54) or ongoing pregnancies versus early pregnancy loss groups (AUC(ROC) = 0.52; 95% CI: 0.47-0.57). Stratification for various low serum levels of LH did not reveal significant differences with respect to conception or pregnancy outcome among different LH levels on stimulation day 1. CONCLUSIONS: Serum LH concentration on stimulation day 1 cannot predict ovarian response, conception and pregnancy outcome in women receiving long-term down-regulation during assisted reproduction treatment.     

Thrombopoietin receptor (Mpl) expression by megakaryocytes in myeloproliferative disorders

The thrombopoietin receptor (Mpl) is involved in the pathogenesis of chronic myeloproliferative disorders (CMPD). In this study, we determined Mpl expression by bone marrow cells and megakaryocytes in CMPD by applying laser microdissection, real-time RT-PCR, and immunohistochemistry. Mpl mRNA expression was significantly increased up to 9-fold in total bone marrow cells (p < 0.001) and up to 4-fold in megakaryocytes in chronic myeloproliferative disorders (n = 73) compared to normal controls (n = 26, p = 0.01). Immunohistochemistry revealed heterogeneous Mpl expression by megakaryocytes in CMPD with a stronger accentuation in idiopathic myelofibrosis (IMF) in comparison to polycythaemia vera (PV) and essential thrombocythemia (ET). In addition to megakaryocytes, the erythropoietic lineage was prominently labelled by Mpl antiserum, with considerably stronger staining in polycythaemia vera. We conclude that, in CMPD, megakaryocytes and erythroid cells exhibit increased Mpl expression levels which may contribute to the sustained proliferation of both cell lineages in CMPD.