[Value of radiomics models based on MRI diffusion weighted imaging and apparent diffusion coefficient in differentiating benign and malignant thyroid nodules]

Objective: To investigate the value of radiomics models based on magnetic resonance imaging (MRI) diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps in distinguishing benign and malignant thyroid nodules. Methods: A cross-sectional study. Clinical data of 148 thyroid nodules (50 benign, 98 malignant) from 140 patients who underwent thyroid MRI examination in Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences between January 2019 and December 2022 were retrospectively analyzed. The nodules were used as the study units, and a leave-one-out method was used to randomly divide the nodules into a training set and a test set at a 7∶3 ratio. Region of interest was segmented and radiomics features were extracted from the DWI and ADC images. In the training set, feature selection was performed using inter-observer agreement analysis, U-test, least absolute shrinkage and selection operator algorithm, and correlation analysis. Four classifiers, including support vector machine (SVM), random forest (RF), k-nearest neighbors (KNN) and logistic regression (LR) were used to build models with the selected features, including the DWI models, ADC models, and combined models. The models were independently tested in the test set. The performance of the radiomics models in distinguishing benign and malignant thyroid nodules was evaluated using the receiver operating characteristic (ROC) curve, with pathological results as the gold standard. Results: Of the 140 patients, there were 40 males and 100 females, with a mean age of (38.4±12.2) years. After feature selection, 11 DWI features and 11 ADC features were used to build the models. In the training set, the AUC values of the combined models were higher than those of the corresponding DWI and ADC models. In the test set, the SVM combined model showed the best predictive performance, with an AUC of 0.873 (95%CI:0.740-0.954), accuracy of 75.6%, sensitivity of 46.7%, specificity of 90.0%, positive predictive value (PPV) of 70.0% and negative predictive value (NPV) of 77.1%, while the RF combined model had an AUC of 0.836 (95%CI:0.695-0.929), accuracy of 77.8%, sensitivity of 40.0%, specificity of 96.7%, PPV of 85.7% and NPV of 76.3%, the KNN combined model had an AUC of 0.832 (95%CI:0.691-0.927), accuracy of 77.8%, sensitivity of 33.3%, specificity of 100%, PPV of 100% and NPV of 75.0%, the LR combined model had an AUC of 0.813 (95%CI:0.669-0.914), accuracy of 77.8%, sensitivity of 60.0%, specificity of 86.7%, PPV of 69.2% and NPV of 81.3%. Conclusions: Radiomics models based on DWI and ADC image features can effectively distinguish benign and malignant thyroid nodules. The SVM combined model had the best prediction performance.

[Analysis of the characteristics of retracted scientific papers in the field of global liver diseases published by Chinese scholars]

Objective: To analyze the characteristics of scientific papers in the field of global liver diseases published by Chinese scholars that were retracted for diverse reasons from the Retraction Watch database, so as to provide a reference to publishing-related papers. Methods: The Retraction Watch database was retrieved for retracted papers in the field of global liver disease published by Chinese scholars from March 1, 2008 to January 28, 2021. The regional distribution, source journals, reasons for retraction, publication and retraction times, and others were analyzed. Results: A total of 101 retracted papers that were distributed across 21 provinces/cities were retrieved. Zhejiang area (n = 17) had the most retracted papers, followed by Shanghai (n = 14), and Beijing (n = 11). The vast majority were research papers (n = 95). The journal PLoS One had the highest number of retracted papers. In terms of time distribution, 2019 (n = 36) had the most retracted papers. 23 papers, accounting for 8.3% of all retractions, were retracted owing to journal or publisher concerns. Liver cancer (34%), liver transplantation (16%), hepatitis (14%), and others were the main areas of retracted papers. Conclusion: Chinese scholars have a large number of retracted articles in the field of global liver diseases. A journal or publisher chooses to retract a manuscript after investigating and discovering more flawed problems, which, however, require further support, revision, and supervision from the editorial and academic circles.

Pro-protein convertase subtilisin/kexin type 9 promotes intestinal tumor development by activating Janus kinase 2/signal transducer and activator of transcription 3/SOCS3 signaling in ApcMin/+ mice

Introduction

Pro-protein convertase subtilisin/kexin type 9 (PCSK9) regulates lipoprotein homeostasis in humans. Evolocumab is a selective PCSK9 inhibitor that can reduce low-density lipoprotein cholesterol (LDLC) level and decrease hypercholesterolemia. The current study aimed to explore whether PCSK9 increases the risk of colorectal cancer.

Methods

First, we utilized the classic intestinal tumor Apc^Min/+ mouse model and PCSK9 knock-in (KI) mice to establish Apc^Min/+PCSK9(KI) mice. Then, we investigated the effect of PCSK9 overexpression in Apc^Min/+PCSK9(KI) mice and PCSK9 inhibition using evolocumab on the progression of intestinal tumors in vivo by hematoxylin and eosin (HE) staining, Western blot, and immunohistochemistry (IHC) assay.

Results

Apc^Min/+PCSK9(KI) mice had higher numbers and larger sizes of adenomas, with 83.3% of these mice developing adenocarcinoma (vs. 16.7% of Apc^Min/+ mice). However, treatment with evolocumab reduced the number and size of adenomas and prevented the development of adenocarcinomas in Apc^Min/+ mice. PCSK9 overexpression reduced tumor cell apoptosis, the Bax/bcl-2 ratio, and the levels of cytokine signaling 3 protein (SOCS3) suppressors, but activated Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling in intestinal tumors. In contrast, evolocumab treatment had the opposite effect on Apc^Min/+mice.

Conclusion

PCSK9 might act as an oncogene or have an oncogenic role in the development and progression of colorectal cancer in vivo via activation of JAK2/STAT3/SOCS3 signaling.

Neuroprotective effects of NEP1-40 and fasudil on Nogo-A expression in neonatal rats with hypoxic-ischemic brain damage

The hypoxic-ischemic encephalopathy caused by peripartum asphyxia is a serious disease in newborn infants, and effective therapies need to be developed to reduce injury-related disorders. We evaluated the effects of NEP1-40 and fasudil on Nogo-A expression in neonatal hypoxic-ischemic brain damage (HIBD) rats. Seven-day-old Wistar rats were randomly divided into control, HIBD, NEP1-40, and fasudil groups. NEP1-40 and fasudil groups were injected intraperitoneally with these compounds. Rat brains at 6, 24, 72 h, and 7 days after HIBD were collected to determine histopathological damage and the expression levels of Nogo-A. Histopathological damage was reduced in NEP1-40 and fasudil groups compared with the untreated HIBD group. The expression of Nogo-A in the HIBD group was significantly higher than that in control, NEP1-40 and fasudil groups at the same times. Compared with the fasudil group, the expression levels of Nogo-A were significantly reduced in the NEP1-40 group. We conclude that NPE1-40 and fasudil have potential for neuroprotective effects in the neonatal rat HIBD model, mediated by inhibiting Nogo-A/ Rho pathways.

A new method for the preservation of aortic valve homografts

BACKGROUND AND AIM OF THE STUDY

Aortic valve homografts were treated with 50% ethanol and glycerol followed by freeze-drying (D-Hydro). Comparative results of fresh versus D-Hydro-treated aortic roots implanted for up to nine months in the descending aorta of sheep with induced aortic regurgitation (AR) are reported.

METHODS

Six fresh and six D-Hydro valves were implanted in 12 sheep for three, six and nine months, and echocardiography and pressures were taken at surgery and sacrifice. Tissue sections were stained with hematoxylin and eosin, von Kossa, Masson's trichrome, Movat's pentachrome, von Willebrand factor, CD3 (a T-cell marker) and smooth muscle alpha-actin.

RESULTS

No grafts had increased gradients after implantation, or at sacrifice. At explantation, fresh homografts showed early pannus formation followed by thrombus, annular dilatation and wall calcification. Leaflets were thickened and progressively retracted. All had severe AR. The appearance of D-Hydro-treated homografts was normal, except for mild leaflet retraction in three, resulting in AR (in two animals the induced AR had healed). Histologically, a T-cell-mediated reaction was evident in the fresh homografts, and collagen distortion was noted. Calcification was present in all fresh specimens and was severe at nine months. D-Hydro roots showed only minor calcification in the six-month samples. Normal collagen, and a complete layer of von Willebrand factor-stained cells were present at three months. At nine months, cell rehabitation extended for two-thirds of the leaflets (alpha-actin +). The inflammatory reaction was very mild, with CD3+-stained cells absent in most samples.

CONCLUSION

Aortic valve homografts treated with the D-Hydro freeze-drying method performed better than fresh homografts due to the absence of thrombus and annulus dilatation, limited calcification, and rehabitation of the aortic wall and parts of the leaflet by myofibroblasts, as well as the presence of a complete endothelial layer on the aortic wall and leaflet.

[Perioperative observation of plasma endothelin in patients with congenital heart disease with pulmonary hypertension underwent open heart surgery]

To elucidate the correlation between endothelin(ET) and pulmonary hypertension, plasma ET was measured perioperatively by radioimmunoassay in 22 patients with pulmonary hypertension who underwent open heart surgery(PH group) in comparison with 16 patients without pulmonary hypertension(non-PH group) also underwent cardiopulmonary bypass(CPB) surgery.

RESULTS

Plasma ET was significantly increased during CPB in both group, Plasma ET decreased rapisly and returned to preoperative level within 6 hours after operation in the non-PH group. In the PH group, however, plasma ET decreased slowly and did not return to preoperative level within 48 hours postoperation.

A study of the junction between glutaraldehyde-treated allogeneic aorta and host aorta

BACKGROUND AND AIM OF THE STUDY

Stentless aortic valve bioprostheses have become popular because of their superior hemodynamics and expected increased durability. However, the stentless bioprosthesis differs from stented valves in that glutaraldehyde (GA)-treated tissue is implanted in direct contact with the native aorta. The effect of GA-treated tissue on host tissue has not been reported.

METHODS

In order to analyze the effect of GA in the healing process, sheep descending aortic conduits treated with 0.625% GA were inserted in the descending thoracic aorta of 10 adult sheep. The implants were removed after 4, 5, 10, 12, 15, 25, 30, 32, 60 and 120 days. The upstream and downstream junctions were evaluated macro- and microscopically, and by immunohistology for smooth muscle cell alpha-actin and von Willebrand factor.

RESULTS

By day 60 of implantation, the GA-treated conduits were calcified. By days 60 and 120, the calcification had spread to the host aorta, and was seen as foci of calcification in the junctional area. Acellular areas were also seen in the host aorta near the anastomosis. A fibrotic layer spanning the abluminal aspect of the junction between the implant and host aorta was present at day 4 and continued through 120 days. This layer was characterized by a progressive increase in collagenous matrix and cellularity, as well as new blood vessel formation. The luminal aspect of the junction had a neointimal layer of variable thickness containing alpha-actin-expressing cells covered by a monolayer of von Willebrand factor-expressing cells, seen at 15-30 days and present through 120 days.

CONCLUSION

In our model, implanting GA-fixed tissue in direct contact with living tissues resulted in cell death and calcification of host tissue within 60 days. The integrity of the junction did not appear to be compromised. This may be of interest in light of the increased popularity of the stentless aortic bioprosthesis.

Significant increase of aortic root volume and commissural area occurs prior to aortic valve opening

BACKGROUND AND AIM OF THE STUDY

The increased use of autologous, homologous or heterologous aortic root demands a detailed knowledge of its anatomy and function. The advent of 3-D digital sonomicrometry offered the opportunity to acquire precise information on the root and leaflet movements during the cardiac cycle.

METHODS

Under cardiopulmonary bypass, sonomicrometry crystals were implanted in the aortic root and valve of eight sheep. Crystals were sutured at each commissure (n = 3), the top of the sinotubular junction (n = 3), lowest point of the annulus (n = 3), and leaflet tip (n = 3). 3-D coordinates of each crystal were recorded, together with left ventricular and aortic root pressures and ECG. When the animal had returned to a stable hemodynamic condition, the maximum and minimum distances between two crystals, and areas between three crystals, were calculated. Changes in root volume and leaflet position were time-related to the pressure changes.

RESULTS

The most significant change between maximum and minimum distance between crystals during the cardiac cycle occurred at the commissural level. Similarly, the triangle defined by the three commissural crystals showed the greatest change in area (47%). The root volume increased by an average of 22%; about 40% of this increase occurred during the isovolumic phase. The aortic leaflets began to open before ejection.

CONCLUSION

We postulate that aortic valve opening is initiated by the outward pull of the commissures. These findings should impact on aortic root surgery.

Behavior of vital and killed autologous pericardium in the descending aorta of sheep

OBJECTIVES

Cardiovascular implants of fresh autologous pericardium produced mixed results including fibrosis with retraction or thinning and dilatation. The reasons for these differences are unknown but may involve activation of cells intrinsic to the tissue implant. To better understand the behavior of autologous pericardial implants, we studied the outcomes of vital pericardium (fresh) versus ethanol-killed pericardium.

METHODS

Fresh and ethanol-killed autologous pericardium was transplanted as a patch, a conduit, or a rectangular flap bisecting the lumen in the descending aorta of sheep. The implants, recovered at 1, 5, 10, 15, and 30 days, were evaluated macroscopically and microscopically and by immunohistologic studies.

RESULTS

Fresh implants showed good preservation with fibrin deposition on day 15. Microscopically, cells positive for alpha-actin and von Willebrand-related antigen appeared in the fibrin by day 10. By day 30 the flap was fibrotic and retracted whereas the patch and conduit retained their original appearance on the luminal aspect. An endothelium-like layer expressing von Willebrand-related antigen was present in the patch and conduit but absent in the flap. In contrast, the ethanol-killed implants were free of fibrin by day 10. By day 30, there were no signs of fibrosis or retraction, and a surface layer of cells expressing von Willebrand-related antigen, characteristic of endothelial cells, was present on all implants. All ethanol-killed implants were repopulated by host cells.

CONCLUSION

The transluminal flap is an interesting model for studying the behavior of intraluminal autologous pericardial cardiovascular implants. Killing of the pericardial implants alleviated the fibrosis and tissue retraction observed with fresh flap implants.

Expanding indications for the Ross procedure

The pulmonary autograft procedure has been shown to provide excellent hemodynamic results in young patients with aortic pathology. However, the use of this procedure in those with more complex aortic disease has not been extensively evaluated. The purpose of this report is to present the application of the Ross procedure in a 21-year-old man with extensive acquired aortic root pathology, both subannular and supraannular, and prosthetic valve dysfunction after two previous procedures.

Aortic root geometry: pattern of differences between leaflets and sinuses of Valsalva

BACKGROUND AND AIMS OF THE STUDY

Growing interest in aortic root replacement with the use of stentless auto-, homo- and xenografts, and new developments in aortic valve conservation demand a deeper understanding of the normal aortic root anatomy.

METHODS

Ten cryopreserved human aortic roots were pressurized, fixed and measured directly (leaflet free edge and attachment) and using three-dimensional computed tomography imaging software (sinus of Valsalva height and volume).

RESULTS

The mean of the measurements of all four parameters yielded a pattern in which the non-coronary sinus (N) structures had the greatest dimensions followed by the right (R) and then the left (L). Non-parametric ANOVA on each of these parameters also showed significant differences among the sinuses yielding a pattern of N > R > L. This pattern determined an angle of tilt between the plane at the base (annulus) and the plane intersecting the sinotubular junction with a mean value of 11 degrees. Linear regression indicated that this angle did not depend on the size of the base (annulus).

CONCLUSIONS

The data showed a geometric pattern of the aortic root, with the structures of the non-coronary sinus being the largest followed by the right and then the left. The possible hemodynamic relevance and surgical implications of these findings need to be explored.

An in vitro study of the correlation between aortic valve diameter and mitral intertrigonal distance: a simple method to select the correct mitral annuloplasty ring size

BACKGROUND AND AIMS OF THE STUDY

The application of the flexible Duran mitral annuloplasty ring in the treatment of various mitral valvular diseases is a physiologically appealing method of surgical repair. However, accurate identification of the trigonal structures, which is crucial in selecting the proper ring size, cannot always be made with certainty. A method is proposed to calculate the intertrigonal distance (ITD) from the aortic diameter.

METHODS

Using digital calipers, the linear intertrigonal distance was measured in human homograft (n = 10) and sheep (n = 10) aortic root specimens. The aortic diameter was obtained from the circumference of the pressurized aortic root. A conversion factor was acquired for each specimen by dividing the aortic diameter with the measured ITD. A single constant conversion factor, which closely approximated the mean of the conversion factors in both groups, was then applied broadly to derive the ITD by calculation from the aortic diameter, which is known. The validity of using this constant conversion factor was tested by comparing the degree of variation of the calculated ITD from the direct measurements of the ITD.

RESULTS

The mean of the conversion factors was 0.79 and 0.80 in the human and the sheep roots, respectively. The value 0.80 was used as the constant conversion factor in both groups for calculating the ITD. A paired comparison t-test in each group showed the difference between the calculated intertrigonal distance and the direct measurements of the ITD to be insignificant, validating the use of 0.80 as a constant conversion factor.

CONCLUSIONS

The results of the study suggest that the conversion factor of 0.80 can be reliably used to obtain a calculated value of the intertrigonal distance; this method has the potential to aid the surgeon in determining the intertrigonal distance and the proper ring size.