Diagnostic feasibility of middle cerebral artery stenosis or occlusion evaluated by TCCS and CEUS: Repeatability, reproducibility, and diagnostic agreement with DSA

AIM

This study aimed to evaluate the feasibility of transcranial color-coded sonography (TCCS) and contrast-enhanced ultrasound (CEUS) in assessing middle cerebral artery (MCA) stem stenosis or occlusion compared to digital subtraction angiography (DSA).

METHODS

A total of 48 cases including 96 MCAs suspected stem stenosis or obstruction in the MCA were assessed by TCCS, CE-TCCS, and DSA. The diameters of the most severe stenosis (Ds), proximal normal artery (Dn), and diameter stenosis rate of MCA were measured using both the color doppler flow imaging (CDFI) modality of TCCS or CEUS and the CEUS imaging modality. The intraclass correlation coefficients (ICCs) and 95 % confidence intervals (CI) were evaluated, and a weighted Kappa value was used to evaluate the intra-observer agreement, inter-observer agreement, agreement between CDFI modality and DSA stenosis or occlusion, and agreement between CEUS imaging modality and DSA stenosis or occlusion.

RESULTS

The ICC results indicated excellent repeatability and reproducibility (all ICCs > 0.75; weighted Kappa values >0.81). Compared with DSA, the weighted Kappa values and 95 % CIs of stenosis (the first measurement was taken by two observers) of CDFI modality and CEUS imaging modality were 0.175 (0.041, 0.308) and 0.779 (0.570, 0.988) for observers A and 0.181 (0.046, 0.316) and 0.779 (0.570, 0.988) for observers B respectively.

CONCLUSION

This study indicates that inter- and intra-observer agreements were good for the direct method of measuring percentages of MCA stenosis by TCCS and CEUS. CEUS imaging modality is a new and reliable imaging modality approach to evaluate the MCAs stenosis and occlusion.

[COVID-19 treated with oral Nirmatrelvir-Ritonavir in 3 children]

Objective: To summarize the application experience and the therapeutic effect of Nirmatrelvir-Ritonavir (trade name: Paxlovid) for COVID-19 in children. Methods: A retrospective analysis was performed on the clinical data, including collecting the clinical manifestations and clinical outcomes, dynamically monitoring the blood routine, hepatic and renal function and SARS-CoV-2 nucleic acid results, and observing the related side effects during the treatment, etc, of 3 cases with COVID-19 treated with Paxlovid admitted to Shanghai Children's Hospital (designated referral hospital for SARS-CoV-2 infection in Shanghai) from May 1^st to June 1^st, 2022. Results: The 3 cases were 12, 14, 17 years of age, among which 2 cases were males, 1 case was female. All 3 cases were mild cases with underlying diseases and risk of developing into severe COVID-19, with symptoms of high fever, sore throat and dry cough. The treatment of Paxlovid at 3^rd day of symptom onset contributed to the symptom-free after 1-2 days and negative results of SARS-CoV-2 nucleic acid after 2-4 days. All patients had no adverse manifestations of gastrointestinal tract and nervous system but a case had little skin rashes, which recovered after the withdrawal of Paxlovid. Three cases had normal hepatic and renal function during the Paxlovid treatment. At 3 months after discharge, no clinical manifestations of post-COVID syndrome were found in all 3 cases. Conclusion: Paxlovid was effective and relatively safe in the treatment of 3 children with COVID-19.

[Surgical diagnosis and treatment of adult huge undifferentiated embryonal sarcoma of the liver]

Objective: To investigate the clinical characteristics of adult undifferentiated embryonal sarcoma of the liver (UESL). Methods: A retrospective analysis was performed on the clinical data of 5 patients with UESL who underwent surgical resection and were pathologically confirmed from January 2005 to December 2020 at the First and the Second Affiliated Hospital of Anhui Medical University. All the patients were female aged from 49 to 77 years old. Preoperative CT showed a solid cystic mass with low density and a slight density of cord like septum. Imaging findings were misdiagnosed as hepatocellular carcinoma or cystadenocarcinoma. CA125 was higher in 3 patients,and AFP in all patients was normal. Results: All patients were treated by surgery. The mean diameter of tumor was 20.2 cm (range:15.0 to 30.0 cm). All five patients had vimentin expression in immunohistochemistry. Three cases underwent complete resection of the tumor and achieved R0 resection,2 of them had tumor free survival until the end of the follow-up (89 and 55 months),the other 1 case died from renal cell carcinoma 158 months later. The remaining 2 cases were radically resected,but the tumors were ruptured during operation,and relapsed after 2 months and 19 months respectively. The overall survival was 3 and 26 months respectively. Conclusions: Radical hepatectomy is the first choice for treatment of UESL. Intraoperative tumor rupture should be avoided and implant metastasis is a major factor affecting the prognosis of UESL.

Regenerative medicine, organ bioengineering and transplantation

Background

Organ transplantation is predicted to increase as life expectancy and the incidence of chronic diseases rises. Regenerative medicine-inspired technologies challenge the efficacy of the current allograft transplantation model.

Methods

A literature review was conducted using the PubMed interface of MEDLINE from the National Library of Medicine. Results were examined for relevance to innovations of organ bioengineering to inform analysis of advances in regenerative medicine affecting organ transplantation. Data reports from the Scientific Registry of Transplant Recipient and Organ Procurement Transplantation Network from 2008 to 2019 of kidney, pancreas, liver, heart, lung and intestine transplants performed, and patients currently on waiting lists for respective organs, were reviewed to demonstrate the shortage and need for transplantable organs.

Results

Regenerative medicine technologies aim to repair and regenerate poorly functioning organs. One goal is to achieve an immunosuppression-free state to improve quality of life, reduce complications and toxicities, and eliminate the cost of lifelong antirejection therapy. Innovative strategies include decellularization to fabricate acellular scaffolds that will be used as a template for organ manufacturing, three-dimensional printing and interspecies blastocyst complementation. Induced pluripotent stem cells are an innovation in stem cell technology which mitigate both the ethical concerns associated with embryonic stem cells and the limitation of other progenitor cells, which lack pluripotency. Regenerative medicine technologies hold promise in a wide array of fields and applications, such as promoting regeneration of native cell lines, growth of new tissue or organs, modelling of disease states, and augmenting the viability of existing ex vivo transplanted organs.

Conclusion

The future of organ bioengineering relies on furthering understanding of organogenesis, in vivo regeneration, regenerative immunology and long-term monitoring of implanted bioengineered organs.

[Effect of TUTF1 expression on the proliferation, apoptosis and prognosis of hepatocellular carcinoma cells]

Objective: To study the relationship between the expressions of tuftelin 1 (TUFT1) and the clinicopathological features of hepatocellular carcinoma and its effect on proliferation and apoptosis, and to explore the relationship between TUFT1 with the development of hepatocellular carcinoma. Methods: Immunohistochemistry was used to detect the expression of TUFT1 in 98 cases of hepatocellular carcinoma and 30 cases of adjacent normal tissues. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of TUFT1 in HCC cell line. The expression of TUFT1 in SMMC-7221 cell lines was down-regulated by lentiviral vector. Cell proliferation assay, clonogenic assay, cell apoptosis assay and cell cycle assay were used to detect proliferation, apoptosis, and cell cycle changes of hepatocarcinoma cells after TUFT1-down-regulation. Statistics were performed using the χ2 test and the t-test. Results: Among the 98 cases of hepatocellular carcinoma, 65 cases (66.33%) were positive for TUFT1, and in 30 cases of adjacent normal tissues, 6 cases (16.67%) were positive for TUFT1, and the difference was statistically significant (χ (2) = 19.956, P < 0.05). The expression of TUFT1 in HCC tissues was related to tumor size, tumor stage, recurrence and metastasis (χ(2) = 6.214, 8.066, 14.400, P < 0.05). After lentiviral vector mediated downregulation of TUFT1 expression in SMMC -7221 cells, the cell proliferation rate [(18.62% ± 0.15%) vs. (67.91% ± 0.62%), P < 0.05], clonality [(8.10% ± 0.80%) vs. (50.80% ± 1.60%), P < 0.05] and G1 phase cells [(36.71% ± 0.69%) vs. (44.65% ± 0.73%), P < 0.05] were significantly decreased, whereas the G2 phase cells [ (15.44% ± 0.53%) vs. (22.31% ± 0.20%), P < 0.05] and the rate of apoptosis [(3.45% ± 0.18%) vs. (5.45% ± 0.06%), P < 0.05] was significantly increased compared with the control group of HCC cells, and the differences were statistically significant. Conclusion: The expression of TUFT1 is highly expressed in hepatocellular carcinoma tissues. Furthermore, the expression of TUFT1 promotes HCC cell proliferation, inhibits the apoptosis, and is poor prognostic factor of hepatocellular carcinoma.

An in vitro DNA phosphorothioate modification reaction

Phosphorothioation (PT) involves the replacement of a nonbridging phosphate oxygen on the DNA backbone with sulfur. In bacteria, the procedure is both sequence- and stereo-specific. We reconstituted the PT reaction using purified DndCDE from Salmonella enterica and IscS from Escherichia coli. We determined that the in vitro process of PT was oxygen sensitive. Only one strand on a double-stranded (ds) DNA substrate was modified in the reaction. The modification was dominant between G and A in the GAAC/GTTC conserved sequence. The modification between G and T required the presence of PT between G and A on the opposite strand. Cysteine, S-adenosyl methionine (SAM) and the formation of an iron-sulfur cluster in DndCDE (DndCDE-FeS) were essential for the process. Results from SAM cleavage reactions support the supposition that PT is a radical SAM reaction. Adenosine triphosphate (ATP) promoted the reaction but was not essential. The data and conclusions presented suggest that the PT reaction in bacteria involves three steps. The first step is the binding of DndCDE-FeS to DNA and searching for the modification sequence, possibly with the help of ATP. Cysteine locks DndCDE-FeS to the modification site with an appropriate protein conformation. SAM triggers the radical SAM reaction to complete the oxygen-sulfur swapping.

Grayscale ultrasonic and shear wave elastographic characteristics of the Achilles' tendon in patients with familial hypercholesterolemia: A pilot study

OBJECTIVE

To investigate the feasibility of grayscale ultrasound and quantitative shear wave elastography (SWE) for assessing the image features and stiffness of the Achilles tendon in patients with familial hypercholesterolemia (FH) compared with healthy controls.

METHODS

A total of 38 Achilles tendons from healthy control participants and 94 from patients with FH were examined with grayscale ultrasound and SWE. Each Achilles tendon examination was performed on 3 different segments (proximal, middle, and distal). The thickness, grayscale image features and elasticity modulus of each segment was measured on longitudinal views.

RESULTS

In Achilles tendons of healthy control participants, the thicknesses of the proximal, middle, and distal segments were (4.46 ± 0.68) mm, (5.41 ± 1.01) mm, and (4.41 ± 0.57) mm, respectively. The grayscale features were diffusely hypoechoic with parallel linear hyperechoic striations. The mean elasticity modulus of the proximal, middle, and distal sites was (418.08 ± 43.13) kPa, (425.78 ± 47.14) kPa, and (407.79 ± 38.74) kPa, respectively. In the FH group, the thicknesses of the proximal, middle, and distal segments were (7.65 ± 3.09) mm, (11.46 ± 4.84) mm, and (8.14 ± 2.90) mm, respectively. The grayscale features were hypoechoic with linear hyperechoic disordered fibre distribution (92/94). Two of 94 Achilles tendons had considerable focal hypoechogenicity. Seventeen of 94 Achilles tendons had calcifications. In the FH group, the mean elasticity modulus of the proximal, middle, and distal segments were (294.86 ± 58.13) kPa, (280.93 ± 63.58) kPa, and (282.41 ± 56.47) kPa, respectively. Statistically significant differences were found between the Achilles tendons of healthy control participants and FH patients in the thicknesses and mean elasticity modulus at the proximal, middle and distal segments of the Achilles tendons (all P < 0.001).

CONCLUSIONS

Our results suggest that the grayscale features and SWE characteristics of the Achilles tendon provided complementary biomechanical information for quantitative assessment the Achilles tendon in patients with FH.

Regulation of dndB Gene Expression in Streptomyces lividans

DNA sulfur modification is a unique modification occurring in the sugar-phosphate backbone of DNA, with a nonbridging oxygen atom substituted with sulfur in a sequence-specific and Rp stereo-specific manner. Bioinformatics, RNA-seq, and in vitro transcriptional analyses have shown that DNA sulfur modification may be involved in epigenetic regulation. However, the in vivo evidence supporting this assertion is not convincing. Here, we aimed to characterize two sulfur-modified sites near the dndB promoter region in Streptomyces lividans. Single mutation of either site had no effect on dndB transcription, whereas double mutation of both sites significantly elevated dndB expression. These findings suggested that DNA sulfur modification affected gene expression, and the role of DNA sulfur modification in epigenetic regulation depended on the number of sulfur-modified sites. We also identified an inverted repeat, the R repeat sequence, and showed that this sequence participated in the positive regulation of dndB gene expression.

[Interaction between APOB gene polymorphism and risk factors in coronary heart disease patients without lipid-lowering treatment]

Objective: To investigate the association between APOB gene R532W polymorphism and the risk of coronary heart disease (CHD) in patients without lipid-lowering treatment and to analyze the interactions between the variation of R532W and different risk factors of CHD. Methods: CHD and non-CHD were diagnosed according to coronary artery angiography (CAG) and/or coronary computed tomography angiogram (CTA) results, as well as clinical features. Blood samples from 771 CHD patients and 772 age- and sex-matched non-CHD controls, who never accepted any lipid-lowering treatments, were collected. R532W was genotyped by HumanExome BeadChip at BGI and strict quality control was made. Firstly, the association between R532W polymorphism and the risk of CHD in 3 genetic models (GA+ AA vs.GG, AA vs. GG+ GA, AA vs. GA vs. GG) after adjusting confounding factors was explored. Then, the interactions between the variation of this loci and risk factors related to CHD were investigated. Results: (1) Total cholesterol (TC) levels were significantly lower in AA genotype than in GA genotype in the total cohort and non-CHD controls, but was similar among the 3 genotypes in CHD patients. (2) R532W GG, GA and AA distribution was 80.7%, 18.2% and 1.2% in CHD patients, and 74.6%, 23.8% and 1.6% in non-CHD controls (P<0.05). (3) R532 polymorphism was related to the incidence of CHD in the dominant model, and A-allele carriers were related to about 35% reduced risk of CHD (OR=0.653, 95% CI 0.502-0.849, P=0.001) after adjusting for confounding factors. (4) R532W polymorphism had positive interactions with hypertension (1.452) and smoke (1.077), while negative interaction with diabetes (0.553) in the occurrence of CHD. Conclusions: APOB gene R532W polymorphism is related to TC levels in Chinese north Han population. A-allele carries of R532W loci is linked with reduced risk of CHD in the absence of lipid-lowering treatment. R532W polymorphism has a positive additive interaction with hypertension and smoke, while a negative additive interaction with diabetes mellitus in the occurrence of CHD.

DNA Phosphorothioate Modification Plays a Role in Peroxides Resistance in Streptomyces lividans

DNA phosphorothioation, conferred by dnd genes, was originally discovered in the soil-dwelling bacterium Streptomyces lividans, and thereafter found to exist in various bacterial genera. However, the physiological significance of this sulfur modification of the DNA backbone remains unknown in S. lividans. Our studies indicate that DNA phosphorothioation has a major role in resistance to oxidative stress in the strain. Although Streptomyces species express multiple catalase/peroxidase and organic hydroperoxide resistance genes to protect them against peroxide damage, a wild type strain of S. lividans exhibited two-fold to 10-fold higher survival, compared to a dnd⁻ mutant, following treatment with peroxides. RNA-seq experiments revealed that, catalase and organic hydroperoxide resistance gene expression were not up-regulated in the wild type strain, suggesting that the resistance to oxidative stress was not due to the up-regulation of these genes by DNA phosphorothioation. Quantitative RT-PCR analysis was conducted to trace the expression of the catalase and the organic hydroperoxide resistance genes after peroxides treatments. A bunch of these genes were activated in the dnd⁻ mutant rather than the wild type strain in response to peroxides. Moreover, the organic hydroperoxide peracetic acid was scavenged more rapidly in the presence than in the absence of phosphorothioate modification, both in vivo and in vitro. The dnd gene cluster can be up-regulated by the disulfide stressor diamide. Overall, our observations suggest that DNA phosphorothioate modification functions as a peroxide resistance system in S. lividans.

Phosphorothioate DNA as an antioxidant in bacteria

Diverse bacteria contain DNA with sulfur incorporated stereo-specifically into their DNA backbone at specific sequences (phosphorothioation). We found that in vitro oxidation of phosphorothioate (PT) DNA by hydrogen peroxide (H(2)O(2)) or peracetic acid has two possible outcomes: DNA backbone cleavage or sulfur removal resulting in restoration of normal DNA backbone. The physiological relevance of this redox reaction was investigated by challenging PT DNA hosting Salmonella enterica cells using H(2)O(2). DNA phosphorothioation was found to correlate with increasing resistance to the growth inhibition by H(2)O(2). Resistance to H(2)O(2) was abolished when each of the three dnd genes, required for phosphorothioation, was inactivated. In vivo, PT DNA is more resistant to the double-strand break damage caused by H(2)O(2) than PT-free DNA. Furthermore, sulfur on the modified DNA was consumed and the DNA was converted to PT-free state when the bacteria were incubated with H(2)O(2). These findings are consistent with a hypothesis that phosphorothioation modification endows DNA with reducing chemical property, which protects the hosting bacteria against peroxide, explaining why this modification is maintained by diverse bacteria.

Dental abnormalities in eight captive giant pandas (Ailuropoda melanoleuca) in China

Dental data from eight adult giant pandas (Ailuropoda melanoleuca) (four females and four males) were collected at the Beijing Zoo from February 2009 to July 2010. Examination findings were recorded in dental charts. All the pandas had different degrees of tooth wear. Incisors, canines and second premolars had the most abnormalities. Five animals had caries; molars were the most affected. Chip fractures were found in seven teeth (incisor, canine and premolar) of five pandas; two had complicated fractures of their canines. Premolars and other teeth were missing in three pandas. Different degrees of dental plaque and calculus were found in all animals. Two pandas had mild gingivitis; the depth of periodontal pockets in all pandas was normal (0-2 mm). Five pandas had abnormal tooth mobility. Samples of dental plaque were collected for microbial culture. Two hundred and fifty-three bacterial strains belonging to 48 species of 23 genera were isolated. Streptococcus, Moraxella, Peptostreptococcus and Porphyromonas were the dominant genera. Further research with larger sample sizes of free-ranging and captive giant pandas will be required in order to demonstrate the absence of the premolar tooth, tooth fractures and the relatively low prevalence of periodontal disease in captive giant pandas.

Sequence variation and genetic diversity in the giant panda

About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottleneck attacks. Afterwards, its genetic diversity seemed to recover to some extent.

[Cerebellar infarction due to vertebral artery dissection in a girl]

We report here a case of vertebral artery dissection, which is rare in childhood. A 12-year-old, previous healthy girl was admitted to our hospital with symptoms of vertigo, tinnitus, hearing loss, nausea and vomiting. Although there was neither higher cortical dysfunction, motor weakness, sensory disturbance nor slurred speech. She could not stand up because of severe vertigo. Cranial magnetic resonance imaging (MRI) revealed a subacute cerebellar infarct. A left vertebral artery angiogram on the hospital day 3 demonstrated a sharp narrowing at the C1-C2 level. After an anticoagulant therapy for about 2 weeks, all the symptoms disappeared except for mild tinnitus. Two months later, a left vertebral artery angiogram showed an abrupt occlusion at the C1 level. MRI T1-weighted images demonstrated a thrombus within the false lumen of the dissected vessels. A flow void revealed the patency of the residual true lumen. From these findings, we made a diagnosis of vertebral artery dissection, which was considered to have caused cerebellar infarction. The patient was mostly normal at discharge, and 100 mg/day of aspirin has been given until present.