Laryngeal paraganglioma: The analysis of misdiagnosed cases and literature review

Laryngeal paraganglioma (LP) is an exceptionally rare neuroendocrine tumor, underscoring importance of accurate identification to preclude misdiagnoses. In this review, we presented two typical misdiagnosed LPs, and offered reviews of LP cases reported over the preceding decade and all documented misdiagnosed LP cases. Furthermore, we systematically investigated the underlying causes of misdiagnosis and elucidated key points for effective differentiation. A retrospective analysis of 28 LP cases revealed a predominant occurrence in middle-aged women, with an average history of 25.1 months. Through an analysis of all misdiagnosed cases (n = 37), supraglottic LPs were frequently misidentified as laryngeal carcinomas and vascular tumors, while subglottic LPs were often misdiagnosed as thyroid cancers. And the occurrence of misdiagnosis resulted in delayed and inappropriate treatments, contributing to the deterioration of LP patients (14 cases, 37.8%). In conclusion, this review endeavored to heighten awareness of LPs, with the ultimate goal of advancing diagnostic precision and enhancing patient outcomes.

Extracellular Vesicles from Urine-Derived Stem Cell for Tissue Engineering and Regenerative Medicine

The potential of urine-derived stem cells (USCs) for tissue engineering and regenerative medicine has attracted much attention during the last few decades. However, it has been suggested that the effects of the USCs may be endowed by their paracrine extracellular vesicles (EVs) rather than their differentiation. Compared with the USCs, the USC-EVs can cross the barriers more easily and safely, and their inclusions may mediate intercellular communication and promote the tissue repair. This article has summarized the current knowledge and applications about the USC-EVs in tissue engineering and regenerative medicine, and discussed the prospects and challenges for using them as an alternative to cell therapy. Impact statement Urine-derived stem cells (USCs) represent a newly discovered type of stem cells, and studies have proved that the beneficial effects of the USCs may be manifested through their paracrine extracellular vesicles (EVs) rather than through their own differentiation, which opens up new avenues for tissue engineering and regenerative medicine strategies. Therefore, this review aims to summarize the latest research progress and potential clinical applications of the USC-EVs, highlighting the promising potential of the USC-EVs as a therapeutic option in kidney regeneration, genital regeneration, nerve regeneration, bone and cartilage regeneration, and wound healing.

[Association between vitamin D level and grip strength in adults aged 50 and older in Shanghai]

Objective: To understand the association between vitamin D level and grip strength in people aged ≥50 years in Shanghai. Methods: Data were obtained from the WHO's Study on Global Ageing and Adult Health in Shanghai during 2018-2019. Logistic regression model was used to analyze the association between vitamin D level and grip strength, and a stratified analysis was conducted for different gender, age and dairy product intake groups. Restricted cubic spline was used to evaluate the dose-response association between vitamin D level and low grip strength. Results: A total of 4 391 participants were included in the study, including 2 054 men (46.8%), with an average age of (67.02±8.81) years. And 1 421 individuals (32.4%) had low grip strength; 1 533 individuals (34.9%) had vitamin D deficiency, and 401 individuals (9.1%) had vitamin D deficiency. After adjusted for confounding factors, the logistic regression results analysis showed that individuals with vitamin D deficiency had a higher risk for low grip strength (OR=1.41, 95%CI: 1.09-1.83). In men, after adjusting for confounding factors, vitamin D deficiency was positively associated with the risk for low grip strength (OR=1.67, 95%CI: 1.12-2.50), but there was no significant association between vitamin D level and grip strength in women (OR=1.30, 95%CI: 0.97-1.74). In age group 60-69 years and ≥80 years, there was significant association between vitamin D deficiency and low grip strength after adjusting for confounding factors (OR=1.57, 95%CI: 1.05-2.35; OR=2.40, 95%CI: 1.08-5.31). In people who had daily intake of dairy product <250 ml, there was positive association between vitamin D deficiency and low grip strength, but there was no significant association in people who had daily dairy product ≥250 ml after adjusting for confounding factors. The restrictive cubic spline demonstrated that risk of low grip strength might decreased with the increase of vitamin D levels, however, the difference was not significant (P>0.05). Conclusions: This study demonstrated that there is association between vitamin D level and grip strength. People with vitamin D deficiency have higher risk for low grip strength.

[Association between dietary pattern and frailty among people aged 50 years and over in Shanghai]

Objective: To investigate dietary patterns of individuals aged ≥50 in Shanghai and analyze their association with frailty. Methods: Using data from the third wave of the Study on Global Ageing and Adult Health in Shanghai conducted between 2018 and 2019. We collected the frequency and average intake of food by the food frequency questionnaire. Factor analysis was used to extract dietary patterns, and a frailty index was constructed using the ratio of the cumulative total score of health deficits to 35 health-related variables considered. We used an ordinal multinomial logistic regression model to analyze the association between dietary patterns and frailty. Results: A total of 3 274 participants aged (67.9±9.2) years were included in the study, including 1 971 (60.2%) men and 1 303 (39.8%) women. We extracted four dietary patterns: high-protein-nuts pattern, potato-bean-vegetable-fruit pattern, poultry-meat pattern, and high-oil-salt pattern. After adjusting for confounding factors, the logistic regression analysis showed that compared with the high-oil-salt pattern, the high-protein-nuts pattern was negatively associated with the risk of higher frailty (OR=0.743, 95%CI: 0.580-0.951). We did not find an association between dietary patterns and frailty between the different gender groups. In the age group 50-64, the high-protein-nuts and potato-bean-vegetable-fruit patterns were negatively correlated with a higher degree of frailty than the high-oil-salt pattern. In the low-level physical activity group, the high-protein-nuts pattern was negatively correlated with a higher degree of frailty than the high-oil-salt pattern (OR=0.509, 95%CI: 0.361-0.720). However, we found no significant effect of the high-protein nuts pattern, potato-bean-vegetable-fruit pattern, and poultry-meat pattern on the risk of higher frailty compared to the high-oil-salt pattern in the moderate to high level of physical activity group. Conclusions: Compared to the high-oil-salt pattern, dietary patterns with a higher intake of high-protein nuts, potatoes, legumes, and fruits and vegetables might be associated with a lower risk of higher frailty in residents aged 50-64 years of age than with a high oil and salt pattern. At the same time, it may have a more significant protective effect in people with lower physical activity levels. It is suggested that a diet rich in high-protein foods, nuts, potatoes, beans, vegetables, and fruits may help reduce and delay the risk of frailty.

Single-cell sequencing of head and neck carcinoma: Transcriptional landscape and prognostic model based on malignant epithelial cell features

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide, and the development of novel therapeutic strategies for HNSCC requires a profound understanding of tumor cells and the tumor microenvironment (TME). Additionally, HNSCC has a poor prognosis, necessitating the use of genetic markers for predicting clinical outcomes in HNSCC. In this study, we performed single-cell sequencing analysis on tumor tissues from seven HNSCC patients, along with one adjacent normal tissue. Firstly, the analysis of epithelial cell clusters revealed two clusters of malignant epithelial cells, characterized by unique gene expression patterns and dysregulated signaling pathways compared to normal epithelial cells. Secondly, the examination of the TME unveiled extensive crosstalk between fibroblasts and malignant epithelial cells, potentially mediated through ligand-receptor interactions such as COL1A1-SDC1, COL1A1-CD44, and COL1A2-SDC1. Furthermore, transcriptional heterogeneity was observed in immune cells present in the TME, including macrophages and dendritic cells. Finally, leveraging the gene expression profiles of malignant epithelial cells, we developed a prognostic model comprising six genes, which we validated using two independent datasets. These findings shed light on the heterogeneity within HNSCC tumors and the intricate interplay between malignant cells and the TME. Importantly, the developed prognostic model demonstrates high efficacy in predicting the survival outcomes of HNSCC patients.

[The influencing factors of functional somatic discomfort in clinical nurses]

Objective: To investigate the functional somatic discomfort status, and to analyze the effect of job stress, hostile attribution bias and ego depletion on functional somatic discomfort in clinical nurses. Methods: In May 2019, 10 cities in Henan Province and Fujian Province were randomly selected as sampling cities. Using the stratified cluster sampling method, nurses of clinical nursing posts in 22 third class hospitals and 23 second class hospitals were selected as the research objects. The general information, job stress, hostile attribution bias, ego depletion and functional somatic discomfort of clinical nurses were investigated by self-designed general information questionnaire, Perceived Stress Scale, Social Information Processing-attribution Bias Questionnaire, Self-regulatory Fatigue Scale, Patient Health Questionnaire-15. 1200 clinical nurses included, and a total of 1159 valid questionnaires were collected, the effective rate of questionnaire collection was 96.6%. The t test was used to compare the difference of the functional somatic discomfort scores of clinical nurses with different demographic characteristicst. The influence of job stress, hostile attribution bias and ego depletion on functional somatic discomfort of clinical nurses were analyzed with Bootstrap. Results: The functional somatic discomfort score of clinical nurses was (8.95±4.38), of which 859 (74.12%) had functional somatic discomfort symptom. The functional somatic discomfort score of clinical nurses aged 36-50 years old was higher than that of 19-35 years old, the functional somatic discomfort score of clinical nurses with service age ≥5 years was higher than that of <5 years, the functional somatic discomfort score of non-permanent clinical nurses was higher than that of permanent clinical nurses, the functional somatic discomfort score of clinical nurses in tertiary hospitals was higher than that of secondary hospitals, the functional somatic discomfort score of clinical nurses in surgical departments were higher than those in non-surgical departments, and the differences were statistically significant (P<0.05). Job stress affected functional somatic discomfort through the single mediating role of hostile attribution bias, the single mediating role of ego depletion, and the chain mediating role of hostile attribution bias and ego depletion (β=0.17, 95%CI: 0.10-0.20; β=0.16, 95%CI: 0.10-0.20; β=0.07, 95%CI: 0.03-0.10; P<0.05) . Conclusion: The functional somatic discomfort symptoms of clinical nurses are significant and varied among different age, working age, employment form, hospital grade and department groups. They are affected by work stress directly and through the separate mediating effect of hostile attribution bias and ego depletion, and the chain mediating effect of hostile attribution bias and ego depletion.

[Clinical value of the MeltPro MTB assays in detection of drug-resistant tuberculosis in paraffin-embedded tissues]

Objective: To evaluate the clinical value of the MeltPro MTB assays in the diagnosis of drug-resistant tuberculosis. Methods: A cross-sectional study design was used to retrospectively collect all 4 551 patients with confirmed tuberculosis between January 2018 and December 2019 at Beijing Chest Hospital, Capital Medical University. Phenotypic drug sensitivity test and GeneXpert MTB/RIF (hereafter referred to as "Xpert") assay were used as gold standards to analyze the accuracy of the probe melting curve method. The clinical value of this technique was also evaluated as a complementary method to conventional assays of drug resistance to increase the detective rate of drug-resistant tuberculosis. Results: By taking the phenotypic drug susceptibility test as the gold standard, the sensitivity of the MeltPro MTB assays to detect resistance to rifampicin, isoniazid, ethambutol and fluoroquinolone was 14/15, 95.7%(22/23), 2/4 and 8/9,respectively; and the specificity was 92.0%(115/125), 93.2%(109/117), 90.4%(123/136) and 93.9%(123/131),respectively; the overall concordance rate was 92.1%(95%CI:89.6%-94.1%),and the Kappa value of the consistency test was 0.63(95%CI:0.55-0.72).By taking the Xpert test results as the reference, the sensitivity of this technology to the detection of rifampicin resistance was 93.6%(44/47), the specificity was100%(310/310), the concordance rate was 99.2%(95%CI:97.6%-99.7%), and the Kappa value of the consistency test was 0.96(95%CI:0.93-0.99). The MeltPro MTB assays had been used in 4 551 confirmed patients; the proportion of patients who obtained effective drug resistance results increased from 83.3% to 87.8%(P<0.01); and detection rate of rifampicin, isoniazid, ethambutol, fluoroquinolone resistance, multidrug and pre-extensive drug resistance cases were increased by 3.2%, 14.7%, 22.2%, 13.7%, 11.2% and 12.5%, respectively. Conclusion: The MeltPro MTB assays show satisfactory accuracy in the diagnosis of drug-resistant tuberculosis. This molecular pathological test is an effective complementary method in improving test positivity of drug-resistant tuberculosis.

[Frailty trajectories in people aged 50 years and above in China]

Objective: To identify distinct frailty trajectories in a cohort of nationwide community adults aged 50 years and above, and explore the relationship between frailty trajectories and their socioeconomic characteristics and behavioral factors at baseline survey. Methods: Data were from the three waves of "Global Ageing and Adult Health Research" (SAGE) by World Health Organization in China. The frailty index is generated from 32 items. Group-based trajectory modeling using a censored normal model was conducted to identify the patterns in frailty progression over time. Multinomial logistic regression model was used to examine the effect of socioeconomic status and behavioral factors on the frailty trajectories. Results: A total of 4 303 adults aged 50 years and above with complete data from all three rounds of project were included in the final analysis. Three frailty trajectories were identified: low and stable trajectory (LT) (56.8%), moderately increased trajectory (MT) (34.4%) and highly increased trajectory (HT) (8.8%). The results of the multinomial logistic regression analysis showed that the HT group was more likely to be women (OR=1.88, 95%CI:1.22-2.92) and rural residents (OR=1.87, 95%CI:1.29-2.70) compared with the LT group. In terms of household wealth per capita, there was a clear gradient in ORs, the people with lower household wealth were more likely to be classified in the HT group. Conclusion: This study identified three patterns of progression of frailty trajectories in population aged 50 years and above in China and highlighted that interventions should target those vulnerable populations with rapid progression of frailty.

[Prevalence and risk factors for pterygium in six rural regions of Yunnan Province]

Objective: To investigate the prevalence and risk factors of pterygium in the rural population aged 40 years and above of 12 ethnic groups in 6 regions of Yunnan Province. Methods: This was a cross-sectional study. According to the method of multistage stratified sampling, samples of the rural population aged 40 years and above were collected from 12 ethnic groups (Han, Yi, Tibetan, Lisu, Bai, Naxi, Zhuang, Miao, Dai, Jingpo, Hani, and Lahu) in six areas (Diqing, Lijiang, Wenshan, Dehong, and Pu'er) of Yunnan Province from March 2019 to November 2019. Anterior segment examination was carried out in the target population with a hand-held slit-lamp, according to which pterygium was diagnosed, while the posterior segment of the eye was assessed by direct ophthalmoscopy. A field questionnaire survey was also conducted. A two-level model was used to study the effects of the location, nationality, sex, age, occupation, outdoor activities, smoking, and alcohol consumption on the prevalence of pterygium, with the ethnic group as the high level and the individual as the low level. Results: Among 9 617 subjects, the total prevalence rate of pterygium was 22.6%, which was adjusted to 19.6% according to the age and gender data of the Statistics Bureau of Yunnan Province. There was significant difference in prevalence of pterygium among six regions after adjusting for age and sex (χ²=146.50, P<0.001). The prevalence of pterygium was the highest in Wenshan (29.4%), followed by Chuxiong (24.4%), Diqing (17.5%), Pu'er (17.5%), Dehong (15.8%), and Lijiang (15.7%) (χ²=146.50, P<0.001). The results of the single factor analysis showed that there was statistically significant difference among different groups of age, gender, nationality, location, history of smoking, drinking, eating habits, sleeping time, continuous use of eye drops, temperature, humidity, altitude, longitude, latitude, and ultraviolet ray (P<0.05). However, the results of the multivariate analysis showed that the main risk factors of pterygium were female(OR=1.357,95%CI:1.173~1.568), advanced age(OR=1.540,95%CI:1.301~1.823), location(OR=1.713,95%CI:1.000~2.667), continuous use of eye drops(OR=1.177,95%CI:1.034~1.340), and more than 40 years of alcohol drinking(OR=1.525, 95%CI: 1.108~2.099), and the protective factor was more than 40 years of smoking(OR=0.723,95%CI:0.544~0.960). Conclusions: The prevalence of pterygium varies greatly among different regions in Yunnan Province. The main factors affecting the prevalence are sex, age, region, smoking history, and drinking history.

[A prospective cohort study on the association between grip strength and cognitive function in adults aged 50 years and above]

Objective: To evaluate the association between grip strength (GS) and cognitive function in a population-based longitudinal cohort of Chinese adults aged ≥50 years. Methods: The study population of 3 600 adults was from the baseline survey and two rounds of follow up of World Health Organization (WHO) study of global ageing and adult health (SAGE) in five districts of Shanghai (Hongkou, Huangpu, Minhang, Qingpu and Pudong) after excluding individuals with self-report stroke and depression. The effects of baseline GS on cognitive function and its changes were evaluated. Factor analysis was applied to generate an overall cognition score based on verbal recall trials, verbal fluency test, forward digit span test and backward digit span test. Linear mixed effects model was used to examine the predictive capability of baseline GS for changes in cognitive function. Results: A total of 3 600 participants aged (61.2±8.1) years at baseline survey were included in this study, including 1 668 (46.3%) men and 1 932 (53.7%) women. The average of baseline GS and total cognitive function score were (28.19±12.18) kg and (58.93±14.56) respectively. Cognitive function score declined significantly during the follow-up, however, the changes were different among different age groups, education level groups and household income groups. After adjusted for age, education level, marital status, household income, co-morbidity of chronic conditions, drinking status, smoking status, physical activity level, vegetable/fruit intakes and BMI, no relationships between the baseline GS and cognitive score at baseline survey and at 1^st follow-up were observed, however, compared with lower GS quartile group, there was a significant relationship between higher baseline GS level and better cognitive function at 2^nd follow-up. The participants with highest GS quartile had better cognitive performance over time (male: β=1.938,95%CI:0.644-3.231,P=0.003, female: β=2.192,95%CI:0.975-3.409,P<0.001 and those aged 50-64 years: β=1.652,95%CI:0.646-2.659,P=0.001) than those with the lowest quartile. Conclusions: Higher baseline GS was significantly related to better cognitive function with slow decline. Thus, it is an indicator of cognitive function in middle-aged and elderly Chinese.

[Gender differences of genetic etiology in the incidence of major depressive disorder among Han freshmen]

Objective: To analyze the gender differences of genetic etiology in the incidence of major depression disorder among Han freshmen. Methods: A 1-year follow-up survey was carried out among 8 079 Han freshmen from Jining, Rizhao and Weifang without lifetime major depressive disorder (MDD) at baseline (April to October 2018) and 4 828 venous blood samples were also collected. After extracting DNA, Sequenom Mass Array time-of-flight mass spectrometry biochip technology was used to detect the genotypes of 17 single nucleotide polymorphisms (SNPs) MDD-related loci. Logistic regression was used for univariate analysis. Generalized multifactor dimension reduction was used to analyze gene-gene interactions. Composite International Diagnostic Interview (CIDI) 3.0 was used for MDD diagnosis. Results: The 1-year incidence of MDD among Han freshmen was 2.23% (95%CI: 1.91%-2.60%) and the gender difference of incidence between males (1.97%, 95%CI: 1.52%-2.56%) and females (2.39%, 95%CI: 1.98%-2.90%) was not statistically significant (P>0.05). AG genotype of rs768705 (nearby gene: TMEM161B) was a risk factor for MDD (OR=1.98, 95%CI: 1.24-2.83). The TC genotype of rs17727765 (nearby gene: CRYBA1) was only a risk factor for MDD in males (OR=9.61, 95%CI: 2.04-45.30). An 8-loci interaction model (PMFBP1, OLFM4, LHPP, ENOX1, TMEM161B, SPPL3, FBXL4 and L3MBTL2) could predict MDD in women with an accuracy rate of 60.05%. No effective prediction model was found for MDD in men. Conclusions: There might be gender differences in the genetic etiology of MDD. Further researches on the genetic causes of MDD in men should be explored.

[The influence of workplace violence on burnout sense in clinical nurses]

Objective: To explore the influence mechanism of intrusive thoughts and ego depletion between effects of workplace violence on burnout sense in clinical nurses. Methods: In May 2019, 10 cities in Henan Province and Fujian Province were selected as sampling cities by the method of grabbing random balls. Using the stratified cluster sampling method, nurses in clinical nursing posts in 22 third class hospitals and 23 second class hospitals were selected as the research objects for a cross-sectional epidemiological survey, including 1200 nurses. A total of 1159 valid questionnaires were collected, and the effective rate was 96.6%. 1159 clinical nurses were investigated by workplace violence scale, event impact scale, self-regulation fatigue scale and job burnout scale. The items contained in the questionnaire were analyzed by exploratory factor analysis with Harman single factor test, and the demographic characteristics of nurses' workplace violence, invasive thinking, self loss and job burnout were compared and analyzed with s-n-k. Results: Those with less than 3 years of service, those with more than 3 years of aggressive thinking and self loss score, and those with less than 3 years of job burnout score; The score of job burnout of unmarried was lower than that of married; The scores of invasive thinking and self loss of non editors were higher than those of current editors; The scores of workplace violence, aggressive thinking, self loss and job burnout of clinical nurses in tertiary hospitals were higher than those in secondary hospitals; The score of job burnout of undergraduate and above is higher than that of junior college and below; The scores of workplace violence, aggressive thinking and self loss of clinical nurses in surgical departments were higher than those in non-surgical departments; The job burnout score of those aged 36 and above was higher than that of those aged <36, The difference was statistically significant (P< 0.05) . Aggressive thinking and self attrition played a mediating role between workplace violence and job burnout. Workplace violence affected job burnout through the single mediating role of aggressive thinking, the single mediating role of self attrition, and the chain mediating role of aggressive thinking self attrition (β=0.16、0.08、0.03, 95%CI: 0.251~0.190、0.121~0.028、0.050~0.012, P<0.05) . Conclusion: Workplace violence affects burnout sense through the independent mediating role of intrusive thoughts and ego depletion and the chain mediating role of intrusive thoughts and ego depletion in clinical nurses.

Mutation of the rice AN1-type zinc-finger protein gene ASL4 causes chloroplast development defects and seedling lethality

Plant zinc-finger proteins play a crucial role in biosynthesis and plant development. However, it is not known whether certain zinc-finger proteins play a role in rice chloroplast development. In this study, a novel rice zinc-finger protein mutant asl4 (albino seedling lethality4), which exhibits an albino lethal phenotype at the seedling stage, was used. Chlorophyll fluorescence analysis and TEM were used to investigate features of the asl4 mutant. The genetic behaviour and function of ASL4 gene were then analysed thorough map-based cloning, transgenic complement and subcellular localization. The albino lethal phenotype was caused by a single nucleotide (G*) deletion mutation on the exon of the ASL4 (LOC_Os09g21710) gene. The ASL4 gene encoded a novel zinc-finger protein containing two ZnF-AN1 domains, which was localized to the nucleocytoplasm. The ASL4 transcripts were highly expressed in all leaves but relatively less in other tissues, suggesting its tissue-specific expression. The transcript levels of associated genes for Chl biosynthesis, photosynthesis and chloroplast development were severely suppressed in asl4 mutants. In conclusion, the absence of ASL4 function caused a defect in chloroplast development and seedling lethality. This is the first published report on the importance of the ZnF-AN1 type zinc-finger protein gene in chloroplast development in rice.

P–313 Endometrial receptivity analysis for personalized embryo transfer in patients with recurrent implantation failure: a retrospective analysis of a Chinese cohort

Study question

To quantify the effectiveness of endometrial receptivity analysis (ERA)-guided personalized embryo transfer (pET) in Chinese women.

Summary answer

ERA-guided pET may remarkably improve pregnancy and implantation rates among Chinese women with Recurrent implantation failure (RIF).

What is known already

RIF is a major cause of infertility, and endometrial receptivity is widely accepted to impact implantation failure. Precision prediction of the WOI, the time when the endometrium is most receptive to the implantation of the embryo, is, therefore, of great significance to improve implantation prospects. Previous studies have shown the effectiveness of ERA for the prediction of the WOI, and how pET, timed by ERA, improves implantation and pregnancy rates; however, the efficacy of ERA-guided pET remains unknown for Chinese women.

Study design, size, duration

Patients in Chengdu Xi’nan Gynecology Hospital (Chengdu, China) who were undergoing frozen embryo transfer (FET) at the blastocyst stage on day five or day six during the period from November 2019 through September 2020 were recruited for this study. A total of 145 eligible patients were included in the study and assigned to the ERA group (n = 67) or the control group (n = 78). Clinical pregnancy outcomes were compared between the two groups.

Participants/materials, setting, methods

Endometrial specimens were collected the from ERA group. Total RNA was extracted from endometrial specimens, the transcriptomic sequencing data were processed using RNA-Seq and the endometrial receptivity status was assessed by the ERA predictor. The endometrium was classified as receptive or non-receptive according to the ERA assessment, and pET was done at the time determined by ERA in the ERA group. Subjects in the control group did not receive ERA and underwent blastocyst transfer normally.

Main results and the role of chance

The demographic and clinical characteristics were comparable between the ERA and control groups (P &gt; 0.05). The ERA test identified 10.45% of samples as receptive and 89.55% of samples as non-receptive in the ERA group, with 70.15% of samples presenting a pre-receptive profile. We observed higher cumulative pregnancy (74.63% vs. 64.10%) and cumulative implantation rate (47.32% vs. 21.68%) rates, and a lower biochemical pregnancy rate (18.00% vs. 34.00%) in the ERA group when compared to the control group (P &lt; 0.05). Additionally, we found higher pregnancy (67.16% vs. 39.74%) and implantation (46.54% vs. 16.94%) rates as well as a lower biochemical pregnancy rate (17.78% vs. 45.16%) after the first ERA test in the ERA group when compared to the control group (P &lt; 0.01).

Limitations, reasons for caution

First, this is a retrospective analysis, which is relatively more biased than prospective clinical trials. Second, the study sample is considerably small. Third, only 10.45% of the subjects were identified as presenting a receptive profile, which limits the comparisons of clinical outcomes between patients with receptive and non-receptive endometria.

Wider implications of the findings: This study demonstrates that the ERA test helps to determine the optimal timing for embryo transfer, improve pregnancy and implantation rates in patients with RIF, and guides the clinical application of the ERA test.

Trial registration number

approval No. 2020–018

Virtual touch imaging quantification shear-wave elastography for breast lesions: the diagnostic value of qualitative and quantitative features

AIM

To investigate the value of the qualitative and quantitative features of Virtual Touch imaging quantification (VTIQ) shear-wave elastography in the characterisation of breast lesions.

MATERIALS AND METHODS

Conventional ultrasound (US) and VTIQ were performed in 148 solid breast lesions in 148 women. During qualitative analysis, patterns of VTIQ were categorised into two patterns, 1 and 2. During quantitative analysis, the mean SWV (SWVmean) and the maximum SWV (SWVmax) of each lesion were used. The sensitivity, specificity, and the areas under the receiver operating characteristic (ROC) curve (Az value) were calculated for conventional US, VTIQ, and combined conventional US and VTIQ.

RESULTS

Malignant lesions were more likely to show VTIQ pattern 2 than the benign lesions (p<0.001). There was no significant difference in the Az values between SWVmean (0.907) and SWVmax (0.902; p=0.572). There was no significant difference in the Az values between the VTIQ pattern (0.884) and SWVmax (p=0.572). The combined conventional US and VTIQ pattern carried a similar Az value (0.949) as compared with the combined conventional US and SWVmax, which yielded an Az value of 0.952 (p=0.683).

CONCLUSION

The combination of either VTIQ pattern or SWVmax and conventional US may be helpful in the characterisation of benign and malignant breast lesions.

[Pathological diagnosis of lung cancer based on deep transfer learning]

Objective: To establish an artificial intelligence (AI)-assisted diagnostic system for lung cancer via deep transfer learning. Methods: The researchers collected 519 lung pathologic slides from 2016 to 2019, covering various lung tissues, including normal tissues, adenocarcinoma, squamous cell carcinoma and small cell carcinoma, from the Beijing Chest Hospital, the Capital Medical University. The slides were digitized by scanner, and 316 slides were used as training set and 203 as the internal test set. The researchers labeled all the training slides by pathologists and establish a semantic segmentation model based on DeepLab v3 with ResNet-50 to detect lung cancers at the pixel level. To perform transfer learning, the researchers utilized the gastric cancer detection model to initialize the deep neural network parameters. The lung cancer detection convolutional neural network was further trained by fine-tuning of the labeled data. The deep learning model was tested by 203 slides in the internal test set and 1 081 slides obtained from TCIA database, named as the external test set. Results: The model trained with transfer learning showed substantial accuracy advantage against the one trained from scratch for the internal test set [area under curve (AUC) 0.988 vs. 0.971, Kappa 0.852 vs. 0.832]. For the external test set, the transferred model achieved an AUC of 0.968 and Kappa of 0.828, indicating superior generalization ability. By studying the predictions made by the model, the researchers obtained deeper understandings of the deep learning model. Conclusions: The lung cancer histopathological diagnostic system achieves higher accuracy and superior generalization ability. With the development of histopathological AI, the transfer learning can effectively train diagnosis models and shorten the learning period, and improve the model performance.

The significance of Siglec-15 expression in resectable non-small cell lung cancer

Siglec-15 (S15) is another important mechanism of tumor immune escape besides the PD-L1/PD-1 pathway and represents a new kind of immune checkpoint inhibitor. However, the associations of tumor Siglec-15 expression with clinicopathological characteristics and outcomes of non-small cell lung cancer (NSCLC), and tumor-infiltrating lymphocytes (TILs) in a tumor microenvironment (TME) have so far been unclear. A total of 324 NSCLC surgical samples on tumor microarray were used in this study for investigating the association of S15 expression with clinicopathological characteristics and overall survival (OS) as well as correlation with TILs using multiplex immunofluorescence staining and PD-L1. Results showed that the expression of S15 in adenocarcinoma was significantly higher than that in squamous cell carcinoma. S15 expression was positively correlated with CD8+ T cell density in the stroma. The expression rate of PD-L1 in lung squamous cell carcinoma was higher than that in lung adenocarcinoma. S15 expression was not associated with the prognosis of early NSCLC. The pathological mechanism of the co-expression of S15 and PD-L1 in resectable NSCLC remains to be further studied.

[Detection of tuberculosis genes associated with drug-resistance in paraffin-embedded tissue specimens using next generation sequencing technology]

Objective: To evaluate the use of multiplex PCR amplicon sequencing (mPCR-NGS) technology in detecting gene mutations related to drug resistance of Mycobacterium tuberculosis (MTB) in formalin-fixed paraffin-embedded tissue specimens, and to explore its clinical value in the diagnosis of drug-resistant tuberculosis. Methods: Fifty clinical MTB strains isolated in the Changping District Tuberculosis Control Institute of Beijing from April 2013 to October 2015 with drug susceptibility test (DST) results of rifampicin, isoniazid, ethambutol, streptomycin, ofloxacin, capreomycin, kanamycin and amikacin available were recovered, including 42 drug-resistant strains and 8 drug-sensitive strains. The mPCR-NGS test was established to detect genes related to the 8 anti-tuberculosis drugs according to the previously published studies and databases. Fifty-five paraffin-embedded tissue specimens from drug-resistant tuberculosis patients were collected in the Department of Pathology, Beijing Chest Hospital, Capital Medical University during November 2017 to September 2018. All the specimens showed no less than one mutation in the gene regions related to drug resistance of any of the 4 drugs (rifampicin, isoniazid, ethambutol or fluoroquinolones) by probe melting curve assay. The effectiveness of mPCR-NGS test was evaluated on clinical MTB isolates using phenotypic DST as the reference. Clinical evaluation of mPCR-NGS test on formalin-fixed paraffin-embedded specimens from TB patients was performed using probe melting curve assay as the reference. The sensitivity, specificity and coincidence of mPCR-NGS were analyzed. Results: Using phenotypic DST as the reference, the sensitivities of the mPCR-NGS for detecting drug-resistance of rifampicin, isoniazid, streptomycin, and ethambutol were 95% (38/40), 93% (27/29), 93% (27/29), and 72% (13/18), respectively; and the specificities were 100% (10/10), 95% (20/21), 100% (21/21), and 94% (30/32), respectively. The sensitivities for capreomycin, kanamycin and amikacin were all 100% (2/2, 3/3, 3/3), and the specificities were 98% (47/48), 100% (33/33) and 100% (47/47), respectively. The sensitivity and specificity of ofloxacin were 70% (7/10) and 100% (40/40), respectively. The total coincidence rate for the 8vdrugs was 94%, and the Kappa value was 0.87. The 55 paraffin-embedded tissue specimens included in this study were all tested by probe melting curve assays. Among them 28 were resistant to rifampicin, 37 resistant to isoniazid, 13 resistant to ethambutol, and 17 resistant to fluoroquinolones. Using the probe melting curve assay as the reference, the sensitivities of the mPCR-NGS for detecting resistant to rifampicin, isoniazid, ethambutol, and fluoroquinolones were 100% (28/28), 95% (35/37), 100%, and 100%, respectively; and the specificities were all 100% (42/42, 38/38). The total coincidence rate of the two methods was 99%, and the Kappa value was 0.98. Conclusions: mPCR-NGS showed good sensitivities and specificities in detecting drug-resistant gene mutations both in clinical MTB isolates and paraffin-embedded tissue specimens. mPCR-NGS has the potential to be an accurate and rapid molecular pathological technology for diagnosis of drug-resistant tuberculosis.

[Epidemiological analysis of cytogenetic abnormalities in patients with newly-diagnosed multiple myeloma: a multi-center retrospective study]

目的

了解我国初诊多发性骨髓瘤（MM）患者细胞遗传学异常（CA）的构成和频率，基于2018年更新的危险分层标准（mSMART3.0）分析双打击MM（DHMM）及三打击MM（THMM）的发生率。

方法

纳入全国5个中心的初诊MM患者，磁珠分选CD138细胞或浆细胞比例≥50%的骨髓标本行初诊间期FISH（iFISH）检测CA的基线结果，分析原发CA（pCA）、继发CA（sCA）、高危（HR）CA和DHMM/THMM的发生率，并分析不同CA组合的情况。

结果

共纳入初诊MM患者1 015例，IgH重排、del（13q）/13q14、1q21扩增、del（17p）发生率分别为54.0%、46.4%、46.1%、9.9%。其中，1q21扩增拷贝数=3、≥4的发生率分别为35.8%、12.7%。454例患者具有完整CA基线结果，pCA中t（4；14）、t（11；14）和t（14；16）发生率分别为14.1%、11.2%和4.8%；44.3%患者携带≥2种CA，包括2种CA（28.0%）、3种CA（13.4%）和≥4种CA（2.9%）；83.3%的1q扩增患者伴其他CA，以del（13q）/13q14最常见（61.1%），IgH重排次之（31.5%）；95.0%的del（17p）患者伴其他CA，以del（13q）/13q14最常见（75.2%），1q21扩增次之（49.5%）；68.6%的IgH重排患者伴其他CA，以del（13q）/13q14和1q21扩增最常见（均为61.9%）；根据2016年国际骨髓瘤工作组的定义，57.7%患者携带HRCA；依据2018年mSMART 3.0的定义，DHMM（HRCA=2）和THMM（HRCA≥3）患者分别占14.3%和2.9%。

结论

更新了我国初诊MM患者的CA谱，发现基于CA的HR MM占初诊MM患者的比例近58%，并首次报道DHMM和THMM的发生率约为17%。

[Consistency of ALK Ventana-D5F3 immunohistochemistry interpretation in lung adenocarcinoma among Chinese histopathologists]

Objective: To understand the consistency of ALK Ventana-D5F3 immunohistochemistry (IHC) interpretation in Chinese lung adenocarcinoma among histopathologists from different hospitals, and to recommend solution for the problems found during the interpretation of ALK IHC in real world, with the aim of the precise selection of patients who can benefit from ALK targeted therapy. Methods: This was a multicenter and retrospective study. A total of 109 lung adenocarcinoma cases with ALK Ventana-D5F3 IHC staining were collected from 31 lung cancer centers in RATICAL research group from January to June in 2018. All cases were scanned into digital imaging with Ventana iSCANcoreo Digital Slide Scanning System and scored by 31 histopathologists from different centers according to ALK binary (positive or negative) interpretation based on its manufacturer's protocol. The cases with high inconsistency rate were further analyzed using FISH/RT-PCR/NGS. Results: There were 49 ALK positive cases and 60 ALK negative cases, confirmed by re-evaluation by the specialist panel. Two cases (No. 2302 and No.2701) scored as positive by local hospitals were rescored as negative, and were confirmed to be negative by RT-PCR/FISH/NGS. The false interpretation rate of these two cases was 58.1% (18/31) and 48.4% (15/31), respectively. Six out of 31 (19.4%) pathologists got 100% accuracy. The minimum consistency between every two pathologists was 75.8%.At least one pathologist gave negative judgement (false negative) or positive judgement (false positive) in the 49 positive or 60 negative cases, accounted for 26.5% (13/49), 41.7% (25/60), respectively, with at least one uncertainty interpretation accounted for 31.2% (34/109). Conclusion: There are certain heterogeneities and misclassifications in the real world interpretation of ALK-D5F3 IHC test, which need to be guided by the oncoming expert consensus based on the real world data.

[Clinical outcome of allogeneic hematopoietic stem cell transplantation with FLAG sequential busulfan/cyclophosphamide conditioning regimen for refractory/relapsed acute myeloid leukemia]

Objective: To investigate the therapeutic effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with FLAG sequential busulfan/cyclophosphamide(Bu/Cy) conditioning regimen for refractory/relapsed acute myeloid leukemia. Methods: From February 2012 to June 2017, 21 patients with refractory/relapsed acute myeloid leukemia underwent allo-HSCT with FLAG sequential Bu/Cy conditioning regimen. Transplantation-related complications and clinical outcome were retrospectively analyzed. Results: After conditioning, no hepatic veno-occlusive disease (VOD) and grade Ⅲ hemorrhagic cystitis occurred. 76.2% (16/21) patients had fever with 4 septicemia. One patient died of septic shock before engraftment. Twenty patients achieved neutrophil engraftment with a median time of 13 days (range, 10 to 21 days). Seventeen patients achieved platelet engraftment with a median time of 18 days (range, 9 to 25 days). The cumulative incidence of acute graft-versus-host disease (aGVHD) was 39.5%, and 3 patients developed grade Ⅲ-Ⅳ aGVHD. Of 19 patients who survived more than 100 days after transplantation, 4 had local chronic graft-versus-host disease (cGVHD). Of 21 patients, the median survival time was 15 months (range, 0.5 to 67 months) post-transplantation. Transplantation-related mortality rate was 28.7%. Leukemia relapse occurred in 4 patients with a median time of 4 months (range, 3 to 8 months) after transplantation. The cumulative relapse rate at 1 year was 21.4%. The 1-year and 3-year overall survival (OS) rates were 60.7% and 54.9% respectively. Log-rank analysis revealed that bone marrow blasts ≥ 20% or extramedullary leukemia before transplantation, poor platelet engraftment and grade Ⅲ-Ⅳ aGVHD were significantly related to shortened OS (P<0.05). Conclusions: Allo-HSCT with FLAG sequential Bu/Cy conditioning regimen in patients with refractory/relapsed myeloid leukemia has acceptable transplantation-related risk and relapse rate. The 1-year and 3-year OS rates are comparable with those in remission patients.

Multi-functional spintronic devices based on boron- or aluminum-doped silicene nanoribbons

Zigzag silicene nanoribbons (ZSiNRs) in the ferromagnetic edge ordering have a metallic behavior, which limits their applications in spintronics. Here a robustly half-metallic property is achieved by the boron substitution doping at the edge of ZSiNRs. When the impurity atom is replaced by the aluminum atom, the doped ZSiNRs possess a spin semiconducting property. Its band gap is suppressed with the increase of ribbon's width, and a pure thermal spin current is achieved by modulating ribbon's width. Moreover, a negative differential thermoelectric resistance in the thermal charge current appears as the temperature gradient increases, which originates from the fact that the spin-up and spin-down thermal charge currents have diverse increasing rates at different temperature gradient regions. Our results put forward a promising route to design multi-functional spintronic devices which may be applied in future low-power-consumption technologies.

Cucumber Plants Baited with Methyl Salicylate Accelerates Scymnus (Pullus) sodalis (Coleoptera: Coccinellidae) Visiting to Reduce Cotton Aphid (Hemiptera: Aphididae) Infestation

The cotton aphid, Aphis gossypii (Glover) (Hemiptera: Aphididae), is a major pest of many crops worldwide and a major cucumber plant pest in Taiwan. Because cotton aphids rapidly develop insecticide resistance and because of the insecticide residue problem, a safe and sustainable method is required to replace conventional chemical control methods. Methyl salicylate (MeSA), a herbivore-induced plant volatile, has been shown to affect aphids' behavior and attract the natural enemies of aphids for reducing their population. Therefore, this study examined the direct effects of MeSA on cotton aphids' settling preference, population development, and attractiveness to natural enemies. The efficiency of using MeSA and the commercial insecticide pymetrozine for reducing the cotton aphid population in laboratory and outdoor cucumber plant pot was also examined. The results showed no difference in winged aphids' settling preference and population development between the MeSA and blank treatments. Cucumber plants infested with cotton aphids and baited with 0.1% or 10% MeSA contained significantly higher numbers of the natural enemy of cotton aphids, namely Scymnus (Pullus) sodalis (Weise) (Coleoptera: Coccinellidae), and MeSA-treated cucumber plants contained a lower number of aphids. Significantly lower cotton aphid numbers were found on cucumber plants within a 10-m range of MeSA application. In addition, fruit yield showed no difference between the MeSA and pymetrozine treatments. According to our findings, 0.1% MeSA application can replace insecticides as a cotton aphid control tool. However, large-scale experiments are necessary to confirm its efficiency and related conservation biological control strategies before further use.

Influence of COL1A2 gene variants on the incidence of hypertensive intracerebral hemorrhage in a Chinese population

Type I collagen (transcribed by COL1A1 and COL1A2 genes) is important for maintaining vessel wall elasticity and is a critical part of the extracellular matrix. We conducted a case-control study to investigate the role of the COL1A2 rs42524 polymorphism in the development of hypertensive intracerebral hemorrhage. Between January 2012 and December 2014, a total of 227 patients with hypertensive intracerebral hemorrhage and 227 controls were selected from the Affiliated Hospital of Yanan University (China). Genotyping of the COL1A2 rs42524 polymorphism was performed using polymerase chain reaction coupled with restriction fragment length polymorphism. By logistic regression analysis, we found that the CC genotype was associated with increased risk of hypertensive intracerebral hemorrhage as compared to the GG genotype (OR = 12.67, 95%CI = 3.03-112.11). In a dominant model, the GC + CC genotype of the COL1A2 rs42524 polymorphism was associated with a 2.57-fold increased risk of hypertensive intracerebral hemorrhage as compared to the GG genotype. In a recessive model, the CC genotype of the COL1A2 rs42524 polymorphism was correlated with a higher risk of hypertensive intracerebral hemorrhage as compared to the GG + GC genotype (OR = 12.07, 95%CI = 2.89-106.75). The GC and CC genotypes of the COL1A2 rs42524 polymorphism were associated with a substantial risk of hypertensive intracerebral hemorrhage among patients who consumed alcohol and used tobacco. In conclusion, our study suggests that the COL1A2 rs42524 polymorphism is associated with the development of hypertensive intracerebral hemorrhage, particularly in conjunction with tobacco use and alcohol consumption.

Clinical application of high-sensitivity cardiac troponin T test in acute myocardial infarction diagnosis

The aim of this study was to investigate the clinical application of a high-sensitivity cardiac troponin T (hs-cTnT) test in the diagnosis of acute myocardial infarction (AMI). Serum levels of hs-cTnT and cardiac troponin I (cTnI) were detected in 240 AMI patients and 200 healthy donors and used to plot receiver operating characteristic (ROC) curves. A clinically applicable diagnostic cut-off value of hs-cTnT was determined from the ROC curve and the diagnostic accuracy of hs-cTnT and cTnI levels in AMI were compared.The serum hs-cTnT levels in the AMI group were higher than 0.014 ng/mL (the 99th percentile of the healthy population), among which hs-cTnT levels in patients with ST-segment elevation myocardial infarction (STEMI) were higher than in patients with non-STEMI (NSTEMI). The area under the ROC curve (AUC) for hs-cTnT was significantly higher than for cTnI, and the detection combining hs-cTnT and creatine kinase isoenzyme (CK-MB) further increased the AUC. When 0.014 ng/mL was set as the cut-off value for hs-cTnT, the diagnostic sensitivity for AMI reached 100% but the specificity was only 45.5%. The diagnostic ability of hs-cTnT for AMI peaked at a cut-off value of 0.035 ng/mL, resulting in the highest Youden index (0.654) and sensitivity and specificity values of 91.8 and 74.9%, respectively. The diagnostic utility of the hs-cTnT test for AMI is superior to the traditional cTnI method. However, since hs-cTnT levels of non-AMI patients can be over the diagnostic cut-off value, further studies are necessary to define clinically applicable cut-off values of hs-cTnT.

Primary lymphomas of the stomach, duodenum and colon: A case report

Synchronous gastric, duodenal and colonic primary lymphomas have a low incidence. Due to the lack of specific symptoms, missed diagnosis or misdiagnosis is easily caused. The present case was initially considered to have gastrointestinal cancer and multiple gastrointestinal polyps, but synchronous gastric, duodenal and colonic primary lymphomas were finally diagnosed by gastrointestinal endoscopy combined with pathological biopsy. Clinicians should raise their awareness of this condition, and comprehensive analysis of clinical characteristics, endoscopic manifestations, pathological characteristics, and imaging findings can help improve the level of diagnosis and treatment.

Maximal, minimal, and mean pulsed Doppler parameters: which should be utilized in the diagnosis of thyroid nodules?

AIM

To compare the diagnostic efficacy of the maximal, minimal, and mean pulsatility index (PI) and resistance index (RI) and determine which should be utilized in the evaluation of thyroid nodules.

MATERIALS AND METHODS

A total of 224 consecutive patients with thyroid nodules were included in this prospective study. Doppler signals from three different nodular arteries were obtained and six Doppler parameters were used for final analysis: maximal PI (PImax), minimal PI (PImin), mean PI (PImean), maximal RI (RImax), minimal RI (RImin), and mean RI (RImean).

RESULTS

Eighty-five patients had malignant and 139 cases had benign thyroid nodules. All three sets of PI and RI parameters were significantly higher in malignant than in benign thyroid nodules (p = 0.000 for all). The area under the receiver operating characteristic (ROC) curve (Az) of PImax was significantly higher than that of PImin (p = 0.046) and higher than that of PImean (p = 0.161). The Az value of RImax was higher than that of RImean and RImin; however, the differences were not significant (p = 0.403, and p = 0.058, respectively). The Az values of the three sets of PI parameters (PImax, PImin, and PImean) were significantly higher than those of the corresponding sets of RI parameters (p = 0.005, p = 0.003, and p = 0.003, respectively).

CONCLUSION

Maximal pulsed Doppler parameters should be utilized in the evaluation of thyroid nodules. PI parameters were superior to the RI parameters in determining malignant nodules.

Rheological and fractal characteristics of unconditioned and conditioned water treatment residuals

The rheological and fractal characteristics of raw (unconditioned) and conditioned water treatment residuals (WTRs) were investigated in this study. Variations in morphology, size, and image fractal dimensions of the flocs/aggregates in these WTR systems with increasing polymer doses were analyzed. The results showed that when the raw WTRs were conditioned with the polymer CZ8688, the optimum polymer dosage was observed at 24 kg/ton dry sludge. The average diameter of irregularly shaped flocs/aggregates in the WTR suspensions increased from 42.54 μm to several hundred micrometers with increasing polymer doses. Furthermore, the aggregates in the conditioned WTR system displayed boundary/surface and mass fractals. At the optimum polymer dosage, the aggregates formed had a volumetric average diameter of about 820.7 μm, with a one-dimensional fractal dimension of 1.01 and a mass fractal dimension of 2.74 on the basis of the image analysis. Rheological tests indicated that the conditioned WTRs at the optimum polymer dosage showed higher levels of shear-thinning behavior than the raw WTRs. Variations in the limiting viscosity (η(∞)) of conditioned WTRs with sludge content could be described by a linear equation, which were different from the often-observed empirical exponential relationship for most municipal sludge. With increasing temperature, the η(∞) of the raw WTRs decreased more rapidly than that of the raw WTRs. Good fitting results for the relationships between lgη(∞)∼T using the Arrhenius equation indicate that the WTRs had a much higher activation energy for viscosity of about 17.86-26.91 J/mol compared with that of anaerobic granular sludge (2.51 J/mol) (Mu and Yu, 2006). In addition, the Bingham plastic model adequately described the rheological behavior of the conditioned WTRs, whereas the rheology of the raw WTRs fit the Herschel-Bulkley model well at only certain sludge contents. Considering the good power-law relationships between the limiting viscosity and sludge content of the conditioned WTRs, their mass fractal dimensions were calculated through the models proposed by Shih et al. (1990), which were 2.48 for these conditioned WTR aggregates. The results demonstrate that conditioned WTRs behave like weak-link flocs/aggregates.

Growth factors and growth hormone enhance in vitro embryo production and post-thaw survival of vitrified bovine blastocysts

The objective of this study was to assess the influence of specific growth factors and growth hormone (GH) in the culture medium on in vitro embryo production and post-thaw survival of vitrified blastocysts. In total, 1673 bovine oocytes were used for evaluating the nuclear status of the oocytes after in vitro maturation (n=560) or for in vitro fertilization (IVF, n=1113) and distributed in five treatment groups: (1). medium only control; (2). activin (10 ng/ml); (3). epidermal growth factor (EGF) (10 ng/ml); (4). insulin 5 microg/ml and (5). GH (100 ng/ml). There was an increase (P<0.05 and P<0.01, respectively) in the percentage of oocytes that reached meta phase II, developed to blastocysts and hatched, as well as in the blastocyst cell number in the groups treated with activin, EGF and GH compared to controls. There was no significant difference between insulin and control groups. A total of 465 blastocysts were vitrified in a three-step protocol using ethylene glycol and polyvinylpyrrolidone. After thawing, embryos were cultured in five treatments groups as described above. Groups EGF and GH had higher (P<0.05) survival rates with a mean blastocyst survival of 95.0+/-1.5 and 93.1+/-3.5%, respectively, while mean hatching rate was higher for EGF and activin groups (75.3+/-3.4 and 62.0+/-3.2%, respectively). Thawed control blastocysts had a mean cell count of 52.7+/-3.3%. With the exception of insulin, all growth factors and GH tested showed higher (P<0.01) total cell numbers when compared to controls. In conclusion, addition of growth factors and GH in the culture media has favorable effects on in vitro maturation, in vitro embryo production, and post-thaw survival of vitrified blastocysts.

Comparison of the effects of using standard and simple portable CO2 incubators on the in vitro developmental competence of bovine embryos reconstituted by somatic cell nuclear transfer

In an attempt to determine the cultural factors that would improve cloning efficiency, we compared the effects of two incubation systems-a simple portable system and a standard CO2 incubator-on the production of bovine embryos by electrofusion of quiescent fetal fibroblast nuclei to enucleated oocytes matured in vitro. While the temperature (38.5 degrees C) and CO2 concentration (5%) were similar in both systems, the portable incubator operated in a vacuum of 300 mmHg and at an O2 level of 8-10%, which is lower than the standard. Although there were no significant differences between the two systems in terms of in vitro oocyte maturation (MII stage), fusion rates, and the number of cells in Day 7 blastocysts, significantly higher proportions of nuclear-transferred oocytes cleaved (P < 0.05) and developed to the blastocyst stage (P < 0.01) in the portable incubator (70.5 +/- 0.6 and 36.1 +/- 1.4%, respectively) than in the standard incubator (64.1 +/- 3.2 and 23.5 +/- 1.4%, respectively). Following the transfer of six blastocysts from the portable incubator group to three recipients, survival rates on Days 60, 90, and 120 were 100, 66.7 and 33.3%, respectively. This relatively high early embryonic loss may be associated with multiple pregnancy complications or other abnormalities of placentation frequently observed in cloned embryos. Further studies using this portable incubator system are needed to determine the optimum levels of O2, CO2, and air pressure.

Improvement of the culture conditions for in vitro production of cattle embryos in a portable CO2 incubator

The effects of different concentrations of growth hormone (GH) on in vitro maturation (IVM), fertilization (IVF) and culture (IVC) of bovine oocyte/embryos in CR1aa or CR2aa media using a simple CO2 incubator were investigated. The IVM/IVF/IVC of oocytes were carried out in the presence of 0, 50, 100 and 200 ng/ml GH in the medium. The proportion of metaphase II oocytes was significantly higher (p < 0.05) in 200 ng/ml compared with 0 ng/ml GH in CR1aa medium (59 versus 85%, respectively), but this effect was not observed under CR2aa. Higher concentrations of GH yielded lower rates of unfertilized ova and thus superior cleavage rates (36.5 +/- 0.2 and 63.5 +/- 2.0% versus 17.5 +/- 0.2 and 82.5 +/- 1.5% or 40.4 +/- 0.6 and 59.6 +/- 1.4% versus 16.6 +/- 1.2 and 83.4 +/- 6.2% for 0 and 200 ng/ml GH in portable or ordinary incubator, respectively) in CR1aa. This dose-dependent effect was also observed in the percentages of transferable embryos, although not statistically different (17.2 +/- 1.7 versus 27.3 +/- 1.8% and 16.6 +/- 3.1 versus 26.0 +/- 1.4%, for 0 versus 200 ng/ml GH in portable and ordinary incubator, respectively). In contrast to the CR1aa, different concentrations of GH in CR2aa medium did not increase either fertilization or cleavage rates. In fact, higher concentrations of GH in this medium negatively affected the rate of transferable embryos. Hence, percentages of transferable embryos obtained in the portable incubator under 0 or 50 ng/ml GH were higher (p < 0.05) compared with those obtained in 100 or 200 ng/ml GH (35.4 +/- 5.7 or 40.5 +/- 5.4% versus 22.4 +/- 2.4 or 15.5 +/- 2.1%, respectively). There was however, no significant difference in the rate of transferable embryos in an ordinary incubator employing CR2aa medium, but the trend was more or less similar to that observed in the portable incubator. Despite the fact that relatively fewer oocytes were employed for the culture in the ordinary incubator, overall results observed employing the simple portable CO2 incubator were within the range of those obtained in an ordinary incubator: implying that the simple portable incubator can effectively be employed for the in vitro production of bovine embryos under field conditions.

The effect of prefreezing the diluent portion of the straw in a step-wise vitrification process using ethylene glycol and polyvinylpyrrolidone to preserve bovine blastocysts

A total of 678 bovine blastocysts, which had been produced by in vitro maturation, fertilization, and culture, were placed into plastic straws and were vitrified in various solutions of ethylene glycol (EG) + polyvinylpyrrolidone (PVP). Part of the straw was loaded with TCM199 medium + 0.3 M trehalose as a diluent; the diluent portions of the straw were prefrozen to either -30 or -196 degrees C. Then, the embryos suspended in the vitrification solution were pipetted into the balance of the straw and vitrified by direct immersion into liquid nitrogen. For thawing, the straws were warmed for 3 s in air and 20 s in a water bath at 39 degrees C and then agitated to mix the diluent and cryoprotectant solution for 5 min followed by culture in TCM199 + 10% FCS + 5 + microg/ml insulin + 50 microg/ml gentamycin sulfate for 72 h. Variables that were examined were the time of exposure to EG prior to vitrification, the PVP concentration, and the temperature of exposure to EG + PVP prior to vitrification. Survival and hatching rates of the blastocysts exposed to 40% EG in four steps at 4 degrees C were higher than those of embryos exposed in two steps (81.3 +/- 4.3% and 80.2 +/- 3.4% vs 67.6 +/- 4.5% and 71.5 +/- 4.7%, respectively; P < 0.05). The same indices were superior following vitrification-thawing of the blastocysts in 40% EG + 20% PVP than it was in 40% EG + 10% PVP (76.1 +/- 5.5% vs 63.7 +/- 1.8%; P < 0.05; and 61.6 +/- 6.0% vs 70.5 +/- 4.7%; P < 0.01, respectively). Exposure to the vitrification solution (40% EG + 20% PVP) at higher temperatures (37.5 degrees C vs 4 degrees C) reduced both survival and hatching rates (45.8 +/- 6.9% vs 83.9 +/- 4.4% and 41.5 +/- 1.8% vs 64.0 +/- 4.7%, respectively; P < 0.001). These results indicate that blastocysts vitrified after prefreezing the diluent portions of the straws do favor developmental competence of in vitro produced embryos.

Bovine Blastocysts Obtained from Reconstructed Cytoplast and Karyoplasts Using a Simple Portable CO2 Incubator

To enable both the multiplication of elite livestock and the engineering of transgenic animals for various agricultural and biochemical purposes, scientists around the world are intensively studying efficient ways of improving developmental competency of bovine embryos reconstructed by somatic cell nuclear transfer. Because it is widely accepted that culture conditions along with many other factors contribute to the developmental competency of reconstructed embryos, this preliminary study was designed to test whether or not bovine reconstructed embryos could develop in vitro using a simple portable CO(2) incubator. CO(2) and O(2) gas tensions and air pressure can be varied using this system. The parameters used in the five conducted trials were low CO(2) (2-5%) and O(2) (8-10%) gas tensions, and negative air pressure (of 300 mm Hg). Chamber temperature was maintained at 38.5 degrees C. Bovine fetal fibroblasts were used as donor karyoplasts and were fused into microsurgically enucleated M II oocytes followed by activation and culture. From the 250 enucleated oocytes, 217 (86.8%) fused, 183 (73.2%) cleaved, and 43 (17.2%) developed to the blastocyst stage. While relatively low developmental rates were achieved, technical proficiency may have been a contributing factor. Further studies using this system are needed to determine optimal levels of O(2), CO(2), and air pressure.

Reduced IL-10 secretion by CD4+ T lymphocytes expressing mutant cystic fibrosis transmembrane conductance regulator (CFTR)

Expression of the CFTR protein is thought to be physiologically important only in exocrine epithelial cells. However, chronic respiratory inflammation and infection remain unexplained phenomena in disease pathogenesis. Non-transformed, antigen-responsive CD4+ T cells cloned from healthy controls and CF patients homozygous or heterozygous for the delta F508 mutation transcribed CFTR mRNA and expressed immunoreactive cytoplasmic CFTR protein. T cell clones (TCC) from controls and CF patients displayed equivalent Ca(2+)-mediated Cl- current; however, TCC from patients with CF but not controls displayed defective cAMP-mediated Cl-current. Although CF-derived TCC preserved mitogen and antigen proliferative responses and specificity to tetanus toxoid epitopes, they selectively secreted approximately 45% less IL-10 compared with control TCC after activation with concanavalin A (Con A) (624 +/- 101 versus 1564 +/- 401 pg/ml per 10(6) cells, respectively; P = 0.04) or anti-CD3/phorbol ester (5148 +/- 1634 versus 11788 +/- 2390 pg/ml; P = 0.05). This difference was independent of atopy. Secretion of interferon-gamma, IL-2, and IL-4 was comparable in CF and control TCC after both forms of activation, while IL-5 was reduced in CF TCC following anti-CD3/phorbol myristate acetate (PMA) but not after Con A. We conclude that expression of mutant CFTR in human TCC is accompanied by ion channel dysfunction characteristic of the CF phenotype, and is accompanied by a reduction in IL-10 secretion after polyclonal activation. It is possible that disruption of IL-10-mediated anti-inflammatory homeostasis may contribute to early onset sustained inflammation in CF airways.

Expression and activities of class IV alcohol dehydrogenase and class III aldehyde dehydrogenase in human mouth

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for the oxidation of ingested ethanol in humans. To study these two enzymes in surgical specimens of attached gingiva and tongue, we have examined the isozyme patterns by agarose isoelectric focusing and determined the enzyme activities. Class IV mu-ADH, class III chi-ADH, and class III ALDH3 were detected in the oral mucosa tissues. Gingival mu-ADH exhibited a pH optimum for ethanol oxidation at 10 and the K(m) value for ethanol (pH 7.5) was estimated to be 27 mM. At pH 7.5 and 30 degrees C, the ADH activities in the gingiva and tongue samples were determined to be 90.0 +/- 5.8 (mean +/- SE; n = 24) and 50.6 +/- 5.1 (n = 3) nmol/min/g tissue (at 33 mM ethanol), and 138 +/- 11 and 55.1 +/- 4.7 nmol/min/g tissue (at 500 mM ethanol), respectively. The ALDH activities at 20 mM acetaldehyde were determined to be 169 +/- 19 and 50.3 +/- 8.1 nmol/min/g tissue for the gingiva and tongue, respectively. We conclude that ethanol can be significantly metabolized in human attached gingiva and lingual mucosa by mu-ADH. The result also suggests that, due to lacking activity of low K(m) ALDH2 and ALDH1, cytotoxic metabolite acetaldehyde may be involved in the etiology of alcohol-related oral injury.

The use of immediate frozen autogenous mandible, for benign tumour mandibular reconstruction

Reimplantation of frozen autogenous lesioned mandible was performed in 31 patients with mandibular bone cysts and tumours. 26 reimplanted grafts survived without complications following surgery. Two cases had postoperative infections which were resolved following appropriate antibiotic treatment. Three grafts were removed due to the severe infection and wound dehiscence. The follow-up from 6 months to 4 years showed that there was no recurrence of the primary lesion in the 28 successful cases. Satisfactory facial contour after surgery was achieved in 19 patients, while other patients showed relatively mild facial disfigurement. The inferior alveolar nerve was repaired in 4 cases and a functional evaluation was made using an acupuncture pressure tester.

Calcium- and CaMKII-dependent chloride secretion induced by the microsomal Ca(2+)-ATPase inhibitor 2,5-di-(tert-butyl)-1,4-hydroquinone in cystic fibrosis pancreatic epithelial cells

Microsomal Ca(2+)-ATPase inhibitors such as thapsigargin (THG), cyclopiazonic acid (CPA) and 2,5-di-(tert-butyl)-1,4-hydroquinone (DBHQ) have been shown to inhibit Ca2+ reuptake by the intracellular stores and increase cytosolic free Ca2+ ([Ca2+]i). DBHQ is a commercially available non-toxic synthetic compound chemically unrelated to THG and CPA. In this study, we tested the feasibility of utilizing DBHQ to improve Cl- secretion via the Ca(2+)-dependent pathway, in the cystic fibrosis (CF)-derived pancreatic epithelial cell line CFPAC-1. DBHQ stimulated 125I efflux and mobilized intracellular free Ca2+ in a dose-dependent manner. The maximal effects were seen at concentrations of 25-50 microM. DBHQ (25 microM) caused a short-term rise in [Ca2+]i in the absence of ambient Ca2+, and a sustained elevation of [Ca2+]i in cell monolayers bathed in the efflux solution (1.2 mM Ca2+), which was largely attenuated by Ni2+ (5 mM). Bath-application of DBHQ induced an outwardly-rectifying whole-cell Cl- current, which was abolished by pipette addition of BAPTA (5 mM) or CaMK [273-302] (20 microM), an inhibitory peptide of multifunctional Ca2+/calmodulin-dependent protein kinase (CaMKII). Pretreatment of monolayers of CFPAC-1 cells with DBHQ for 4-5 min significantly increased the Ca(2+)-independent or autonomous activity of CaMKII assayed in the cell homogenates. Thus, DBHQ appears to enhance Cl- channel activity via a Ca(2+)-dependent mechanism involving CaMKII. Pretreatment of CFPAC-1 cells with up to 50 microM DBHQ for 6 h did not cause any detectable change in cell viability and did not significantly affect the cell proliferation rate. These results suggest that appropriate selective microsomal Ca(2+)-ATPase inhibitors may be therapeutically useful in improving Cl- secretion in CF epithelial cells.

[Effects on the growth and development of mandible with different treatment following condylar neck fracture in rat]

The condylar necks of young rats are fractured on this experiment.Fractures are treated with nonfixation and fixation,The growth and development of mandible can be interrupted in two groups,with a relatively small in condylar head,a relatively thick in condylar neck.A coronoid and a mandible length are relatively short.But the growth and development of mandible almost are completed,bilateral mandibles are almost symmetry except for ramus.The difference are not found in between two groups.The results of this study implied that young condylar neck fracture may be treated by conservation.

Activation of CFTR chloride current by nitric oxide in human T lymphocytes

Nitric oxide, which is produced by cytokine-activated mononuclear cells, is thought to play an important role in inflammation and immunity. While the function of nitric oxide as a direct cytotoxic effector molecule is well established, its function as a transducer molecule in immune cells is not. By use of whole-cell patch clamp recordings, we show that nitric oxide activates cystic fibrosis transmembrane conductance regulator CI- currents in normal human cloned T cells by a cGMP-dependent mechanism. This pathway is defective in cystic fibrosis-derived human cloned T cells. These findings not only delineate a novel transduction mechanism for nitric oxide but also support the hypothesis that an intrinsic immune defect may exist in cystic fibrosis.

Relationship of gingival calculus and bleeding on probing in CPITN code 2 sextants

The aims of this study were twofold: firstly, to evaluate the relationship of supra- or subgingival calculus and bleeding on probing (BOP) in sextants coded 2 in the Community Periodontal Index of Treatment Needs (CPITN); and secondly, to compare the differences in four investigations in Taiwan, Hong Kong, Japan and Norway. In a national survey, a total of 2658 Chinese dentate adults were examined by using modified CPITN in the Taiwan area from 1985 to 1987. Sextants given Code 2 were divided into four subclassifications: supragingival calculus with bleeding (I+), supragingival calculus without bleeding (I-), subgingival calculus with bleeding (II+) and subgingival calculus without bleeding (II-). The results showed that of the 9394 sextants given Code 2, the highest percentage (70%) were characterized by the presence of subgingival calculus with bleeding and the lowest percentage (4%) by supragingival calculus with bleeding. The ratio of sextants coded 2 with only supragingival calculus versus subgingival was 1:6.2. The bleeding to nonbleeding ratio of sextants coded 2 in this study was similar to the Hong Kong study. However, differences among Taiwan, Japan and Norway were found. The results indicated that sextants with subgingival calculus had a higher tendency to BOP, with a ratio of 4:1. Those with supragingival calculus had a ratio of 3:7. We conclude therefore, that it is essential to scale teeth to remove subgingival calculus for determination of the necessity of periodontal treatment.

Effects of butyrate on the erythropoietin receptor of cell line IW201

The murine erythroleukemic cell line, IW201, normally expresses only low-affinity erythropoietin receptors. Exposure of these cells for 48 hours to sodium butyrate results in a change in receptor kd from about 600 pmol/L to 100 to 200 pmol/L. This change in affinity is accompanied by downregulation of both receptor number and receptor mRNA. Cells exposed to sodium butyrate for 2 hours show a similar change in kd but no change in receptor number. The butyrate effect on kd at 2 hours is abrogated by either cycloheximide or actinomycin D. These data indicate that an accessory protein induced by sodium butyrate is responsible for high-affinity binding of erythropoietin.

Stimulation of chloride secretion by P1 purinoceptor agonists in cystic fibrosis phenotype airway epithelial cell line CFPEo-

1. P1 purinoceptor agonists like adenosine have been shown to stimulate Cl- transport in secretory epithelia. In the present study, we investigated whether P1 agonist-induced Cl- secretion is preserved in cystic fibrosis airway epithelium and which signalling mechanism is involved. The effects of purinoceptor agonists on Cl- secretion were examined in a transformed cystic fibrosis airway phenotype epithelial cell line, CFPEo-. 2. Addition of adenosine (ADO; 0.1-1 mM) markedly increased 125I efflux rate. The rank order of potency of purinoceptor agonists in stimulating 125I efflux was ADO > AMP > ADP approximately equal to ATP. A similar order of potency was seen in transformed cystic fibrosis nasal polyp cells, CFNPEo- (ADO > ATP > AMP > ADP). These results are consistent with the activation of Cl- secretion via a P1 purinoceptor. 3. The P1 agonists tested (at 0.01 and 0.1 mM) revealed a rank order of potency of 5'-N-ethylcarboxamine adenosine (NECA) > 2-chloro-adenosine (2-Cl-ADO) > R-phenylisopropyl adenosine (R-PIA). 4. The known potent A2 adenosine receptor (A2AR) agonist, 5'-(N-cyclopropyl) carboxamidoadenosine (CPCA, 2 microM) but not the A1 adenosine receptor agonist, N6-phenyl adenosine (N6-phenyl ADO, 10 microM) markedly increased 125I efflux rate (baseline, 5.9 +/- 2.0% min-1, + CPCA, 10.9 +/- 0.6% min-1; P < 0.01). The stimulant effect of CPCA (10 microM) was abolished by addition of the A2AR antagonist 3,7-dimethyl-1-propargylxanthine (DMPX) (100 microM; reported K(i) = 11 +/- 3 microM). These results favour the involvement of A2AR. 5. ADO (0.1-mM) and CPCA (2 microM) both induced a marked increase in intracellular [Ca2+] ([Ca2+]i); the effect of the latter was again abolished by pretreatment of the cells with DMPX. By contrast, N6-phenyl ADO did not affect [Ca2+]i. 6. In patch-clamp experiments, ADO (1 mM) induced an outwardly-rectified whole-cell Cl- current (baseline, 2.5 +/- 0.8 pA pF-1, + ADO, 78.4 +/- 23.8 pA pF-1; P < 0.02), which was largely inhibited in cells internally perfused with a selective inhibitory peptide of the multifunctional Ca2+/calmodulin-dependent protein kinase, CaMK [273-302] (20 microM), as compared to a control peptide, CaMK [284-302]. Addition of BAPTA (10 mM), a Ca2+ chelator, to the perfusion pipette also abolished the ADO-elicited Cl- current. 7. In conclusion, our results suggest that A2AR participates in regulation of airway C1 secretion via aCa2+-dependent signalling pathway, which involves CaMK and appears to be at least partially conserved in cystic fibrosis airway epithelial cells.

Activation of intestinal CFTR Cl- channel by heat-stable enterotoxin and guanylin via cAMP-dependent protein kinase

Heat-stable enterotoxins (STa) produced by pathogenic bacteria induce profound salt and water secretion in the gut, leading to diarrhea. Recently, guanylin, an endogenous peptide with properties similar to STa, was identified. While STa and guanylin bind to the same receptor guanylyl cyclase and raise cell cGMP, the signaling mechanism distal to cGMP remains controversial. Here we show that STa, guanylin and cGMP each activate intestinal Cl- secretion, and that this is abolished by inhibitors of cAMP-dependent protein kinase (PKA), suggesting that PKA is a major mediator of this effect. These agents induce Cl- secretion only in cells expressing the wild-type CFTR, indicating that this molecule is the final common effector of the signaling pathway. The involvement of CFTR suggests a possible cystic fibrosis heterozygote advantage against STa-induced diarrhea.

Hemin or butyrate increases constitutive erythropoietin formation by mouse erythroleukemia cell lines

The murine erythroleukemic cell lines NN10 and IW32 secrete erythropoietin (Epo) constitutively. Although both cell lines have Epo receptors (Epo-R), they do not respond to external Epo to undergo erythroid differentiation. In both cell lines, hemoglobin synthesis can be induced by hemin or butyrate. We report here on the effects of these two inducers on Epo production by the same cell lines. Both hemin and butyrate caused a three- to five-fold increase in Epo secretion on a percell basis. The effects were dose- and time-dependent, as was found previously for hemoglobin synthesis. The mechanism of the effect on Epo secretion is posttranscriptional, since the steady-state level of Epo mRNA was not altered by the inducers.

Evidence for an accessory component that increases the affinity of the erythropoietin receptor

Evidence for an accessory component that can modify the affinity of the erythropoietin (Epo) receptor is presented. Dihydrofolate reductase (DHFR)-deficient Chinese hamster ovary (CHO) cells were transfected with a plasmid containing the Epo receptor cDNA (derived from murine erythroleukemia cells with only low affinity receptors) and DHFR cDNA. The cells expressed both high and low affinity receptors. Upon amplification with methotrexate (MTX), only the number of low affinity receptors increased, suggesting that there was a constitutively expressed cellular component in CHO cells that can increase Epo receptor affinity. Further support for this hypothesis was provided by our finding that fusion of IW 201 cells, which have only low affinity receptors, with nontransfected CHO cells, which have no Epo receptors, resulted in high affinity binding sites for Epo.

[Effect of anhydrous glycerol injection into the mental foramen of rabbit on inferior nerve:An experimental study]

In this experiment anhydrous glycerol was injected into the mental foramen of rabbits to determine neurolytic effects on the peripheral trigeminal nerve by electrohysiologic and morphologic methods.The rabbits underwent unilateral injection of anhydrous glycerol and the control side was injected with normal saline.The results show that partial fibers are effected (myelinated and unmyelinated fibers at random).Glycerol injection increased the average latencies and reduced the average amplitudes of compound action potentials.Morphologic examination disclosed myelin swelling,disintergrationan d axonal shrinking,axonolysis.One week after the injection,eletrophysiologic and morphologic changes were most severe and signs of regeneration were noted in the fifth week,By 16 weeks after injection,the nerve fibers appeared almost normal.

Receptor binding of asialoerythropoietin

The interaction of 125I-asialoerythropoietin (asialoepo) with receptors has been characterized both by binding assay and affinity cross-linking. Purified spleen cells from mice infected with the anemia strain of Friend virus (FVA cells) have receptors for 125I-asialoepo with two classes of affinity constant: one with Kd = 0.02-0.03 nM and 300-400 per cell, the other with lower affinity (Kd = 0.9-1.2 nM) and 1,000-1,200 per cell. The Kd value for the high affinity site is one-third of that for the binding of native 125I-erythropoietin (125I-epo) to the same FVA cells (Kd = 0.08-0.1 nM). Using 125I-asialoepo or 125I-epo affinity cross-linking methods, we find two components with apparent molecular weights of 88 kDa and 105 kDa in FVA cells, and in the transformed mouse cell lines, 201, IW32, and NN10, in agreement with earlier studies using 125I-epo. These results indicate that 125I-asialoepo binds to the same receptors as 125I-epo, but with greater affinity for the high affinity site. Since 201 cells contain only a single class of lower affinity receptors for erythropoietin (epo), finding the same two components as found for FVA cells by cross-linking experiment indicates that the two components do not represent the two classes of receptor.