[Advance on theoretical epidemiology models research of prevention and control of COVID-19]

COVID-19 has brought a significant impact to the global health system, and also opportunities and challenges to epidemiological researches. Theoretical epidemiological models can simulate the process of epidemic in scenarios under different conditions. Therefore, modeling researches can analyze the epidemical trend of COVID-19, predict epidemical risks, and evaluate effects of different control measures and vaccine policies. Theoretical epidemiological modeling researches provide scientific advice for the prevention and control of infectious diseases, and play a crucial role in containing COVID-19 over the past year. In this study, we review the theoretical epidemiological modeling researches on COVID-19 and summarize the role of theoretical epidemiological models in the prevention and control of COVID-19, in order to provide reference for the combination of mathematical modeling and epidemic control.

Diagnostic value of maximum signal intensity on T1-weighted MRI images for differentiating parotid gland tumours along with pathological correlation

AIM

To investigate the efficacy of the maximum signal intensity of tumour on T1-weighted magnetic resonance imaging (MRI) images for differentiating Warthin's tumours (WTs) from pleomorphic adenomas (PAs) and malignant tumours (MTs).

MATERIALS AND METHODS

One hundred and fifty-four histopathologically confirmed parotid tumours, including 76 PAs, 45 WTs, and 33 MTs, were analysed. MRI results were compared with pathological findings. The maximum signal intensity of tumour and the average signal intensity of spinal cord were measured on T1-weighted images, then the tumour-to-spinal cord signal intensity ratio (T1-max-SIR) was calculated. The distribution of T1-max-SIRs among the three groups of tumours was analysed using the Mann-Whitney U-test. Receiver operating characteristic curves were generated to assess the ability of T1-max-SIRs to differentiate parotid tumours. In addition, the interobserver agreement between readers was assessed using interclass correlation coefficient (ICC).

RESULTS

T1-max-SIRs were higher in WTs than in PAs (p<0.001) and MTs (p<0.001), and no significant difference was found between PAs and MTs (p=0.151). The area under the curve (AUC) of T1-max-SIRs for differentiating WTs from PAs was 0.901, with a sensitivity of 91.1% and a specificity of 82.9%. The AUC of T1-max-SIRs for differentiating WTs from MTs was 0.851, with a sensitivity of 88.9% and a specificity of 78.8%. Readers had excellent interobserver agreement on T1-max-SIRs (ICC = 0.989; 95% confidence interval, 0.985-0.992).

CONCLUSIONS

T1-max-SIRs can be useful for differentiating WTs from PAs and MTs with high diagnostic efficiency.

[Construction of urban scale-free network model and its epidemiological significance in the prevention and control of COVID-19]

COVID-19 is a public health emergency currently. In this study, a scale-free network model is established based on the Spring Migration data in 2020.The cities is clustered into three different modules. The epidemic of the cities in the black module was the most serious, followed by the red and the cyan. The black module contains 9 cities in Zhejiang province and 8 cities in Guangdong province, most of them located in the southeast coastal economic belt. These cities should be the key cities for epidemic prevention and control.

[Research progress on the association between HIV antiretroviral therapy and the outbreak]

Since the implementation of antiretroviral therapy (ART), it has achieved remarkable results in the field of HIV/AIDS treatment. However, when the treatment is applied to the population-level, the actual impact of ART on the HIV epidemic becomes a hot topic in the field. This paper will summarize the research on ART and HIV epidemic in recent years, and discuss the impact of ART on the trend of HIV epidemic, so as to provide scientific support and suggestions for the role of treatment is prevention.

[The clinical features of patients with lymphoplasmacytic diseases harboring MyD88 L265P mutation]

Objective: To explore the clinical features of lymphoplasmacytic diseases with MyD88 L265P mutation. Methods: To analyze the distribution of MYD88 L265P mutation in patients with lymphoplasmacytic diseases by using of ARMS PCR-CE. Results: There were 25(30.9%) MyD88 L265P mutated patients in 81 patients. The mutation was frequently observed in 14 patients with WM (77.8%, 14/18), 2 patients with lymphoplasmacytic lymphoma (66.7%, 2/3), 1 acute lymphocytic leukemia patient (50.0%, 1/2), 3 multiple myeloma patients (30.0%, 3/10), 1 patient with monoclonal gammopathy of undetermined significance (25%, 1/4), 3 patients with chronic lymphocytic leukemia (13.0%, 3/23) and 1 lymphoma patient (4.8%, 1/21). 20 (80%, 20/25) patients were identified with IgM subtype. Compared with wild-type group of 56 cases, mutated patients were older (median age: 67 years vs 55 years, P< 0.001), with lower WBC count (median count: 5.23 × 109/L vs 10.80 × 109/L, P=0.001), lower HGB level (median count: 85 g/L vs 119 g/L, P<0.001). Conclusion: MyD88 L265P mutation was mainly observed in patients with IgM subtype lymphoplasmacytic diseases, and Waldenstrom' s macroglobulinemia was the most common disease. Compared with the wild-type group, patients with MyD88 L265P mutation were older and had lower WBC count, lower level of HGB. However, further studies were needed to test the prognostic value of MyD88 L265P mutation.

[Association between genetic variants in microRNA biosynthesis genes and the risk of head and neck squamous cell carcinoma]

OBJECTIVE

To investigate the association between genetic variants in microRNA biosynthesis genes and the risk of head and neck squamous cell carcinoma (HNSCC).

METHODS

A case-control study was conducted with 576 HNSCC patients and 1 552 healthy controls matched by factors as age-(±5 years) and sex. Eight potentially functional single nucleotide polymorphism loci in microRNA biosynthesis genes (DICER1, GEMIN3, and PIWIL1) were genotyped using the Illumina Infinium BeadChip platform. Univariate and multivariate logistic regression models were performed to assess the association between genotypes and HNSCC risk.

RESULTS

The allele frequencies of rs1106042 (G> A) in PIWIL1 were significantly different between the cases and controls (P=0.011). After controlling for factors as age, sex, smoking and alcohol intake, the A allele of rs1106042 showed a decreased risk of HNSCC (additive model: adjusted OR=0.73, 95% CI: 0.57-0.93, P=0.011). RESULTS from the stratification analysis by age, sex, smoking, alcohol intake and tumor sites showed that the effect of rs1106042 A allele on HNSCC risk was significant in older age groups (≥60), females, nonsmokers, non-alcohol drinkers, and subjects with oral cavity cancer (P<0.05).

CONCLUSION

Potentially, functional single nucleotide polymorphism in PIWIL1 might modify the risk of HNSCC in China.

[Effects of IL10-592 locus of AA genotype on the incidence of aGVHD and survival after HLA-matched unrelated allogeneic hematopoietic stem cell transplantation]

OBJECTIVE

To explore the impact of IL10-592 (rs1800872) single nucleic acid polymorphism (SNP) on the prognosis of HLA matched unrelated hematopoietic stem cell transplantation (HSCT).

METHODS

The polymorphism of IL10-592 in 104 recipient-donor pairs and 100 healthy volunteers was analyzed with sequence based typing (SBT).

RESULTS

When the genotype of IL10-592 in donors and recipients matched, AA/AA genotype had higher incidence of Ⅲ-Ⅳ aGVHD than AC/AC or CC/CC genotype (47.1%, 3.7%, 0, P=0.002). When the genotype of IL10-592 in donors and recipients mismatched, recipients with AC genotype or donors with AA genotype, there was significant different incidence of Ⅲ-ⅣaGVHD among donors or recipients with different genotype (P=0.046, P=0.041). The recipients with AA genotype had higher incidence of Ⅲ-Ⅳ aGVHD than AC or CC genotype (27.8% vs 10.2%, 11.1%; P=0.072), and higher incidence of intestinal aGVHD (22.2% vs 5.1%,11.1%; P=0.040) , lower incidence of 2-year overall survival (OS: 48.2% vs 75.1%, 85.7%; P=0.002), lower incidence of 2 year disease free survival (DFS: 48.5% vs 66.3%, 76.2%; P=0.045). Patients had higher incidence of Ⅲ-Ⅳ aGVHD with donors of AA genotype than with donors of AC or CC genotype (26.5% vs 8.9%, 0; P= 0.024), and higher incidence of intestinal aGVHD (20.4% vs 4.4%, 0; P=0.026). In multivariate analysis, the genotype of IL10-592AA in recipients and donors had increased risk of Ⅲ-Ⅳ aGVHD (OR=3.3, P= 0.049; OR=3.9, P=0.043). There were no statistical differences on the incidence of cGVHD and relapse.

CONCLUSION

In HLA-10/10 matched unrelated HSCT, the presence of IL10-592 AA genotype in recipients and/or donors is an adverse factor for Ⅲ-ⅣaGVHD, worse OS and 2-year DFS.

Idiopathic orbital pseudotumour

Idiopathic orbital pseudotumour (IOP) is a benign inflammatory condition usually confined to the orbit. This may involve single or multiple intraorbital structures. Extraorbital extension can also occur. The imaging appearances often mimic other orbital diseases. Both computed tomography (CT) and magnetic resonance imaging (MRI) are frequently used to investigate orbital diseases, and it is important for radiologists to be aware of the variety of imaging appearances that occur in IOP. We present the imaging appearances in histopathologically confirmed cases of IOP and discuss the clinical features, natural history, and differential diagnosis of this condition.

3 T MR cholangiopancreatography appearances of biliary ascariasis

AIM

To evaluate the 3 T MR cholangiopancreatography (MRCP) appearances of biliary ascariasis.

MATERIALS AND METHODS

Nine patients with a MRCP diagnosis of biliary ascariasis were reviewed. All patients had endoscopic retrograde cholangiopancreatography (ERCP) or surgical confirmation of the disease.

RESULTS

On thin-slab MRCP imaging, Ascaris worms are clearly demarcated within the biliary tree. All the identified worms demonstrated a characteristic three-parallel-lines appearance. The middle high-signal intensity line is sandwiched between two low-signal intensity lines and they are in turn surrounded by high signal bile. On thick-slab MRCP the worms also show the three-line sign but with less clarity. However, thick-slab MRCP has the advantage of providing three-dimensional ERCP-like images of the pancreaticobiliary system.

CONCLUSION

The "three-line" sign appears to be a characteristic sign of biliary ascariasis on 3 T MRCP.

N-doped SiO2/TiO2 mesoporous nanoparticles with enhanced photocatalytic activity under visible-light irradiation

Mesoporous nanocrystalline N-doped SiO2/TiO2 visible-light photocatalysts were prepared by treating SiO2/TiO2 xerogels in a flow of nitrogen gas bubbled through concentrated ammonia solution. Structural characterization and performance analysis results revealed that the addition of SiO2 remarkably altered the phase composition, specific surface area, microstructure, as well as the photocatalytic activity of N-doped TiO2. The presence of SiO2 in N-doped TiO2 particles suppressed the formation of rutile phase and the crystal growth of N-doped TiO2 particles during thermal calcinations. When weight ratio of SiO2/TiO2 was in 0.05-0.20, the N-doped SiO2/TiO2 exhibited higher photocatalytic activity than the N-doped TiO2, and optimum ratio was found to be 0.05. The enhanced photocatalytic activity could be attributed to the higher specific area, larger pore volume, and more surface hydroxyl groups in the catalyst.

Cystic echinococcosis in semi-nomadic pastoral communities in north-west China

In order to determine the prevalence of human cystic echinococcosis (CE) in semi-nomadic traditional pastoralist groups in north-west China, 2 large community studies were undertaken in Altai and Tacheng Prefectures in 1990/91 and 1995/96, respectively. The Kekergash community (Altai) comprised mainly ethnic Kazakhs, whereas the Narenhebuke community (Tacheng) comprised mainly Mongolians. Populations were screened for CE by abdominal ultrasound scan (US) and serological tests. The total prevalence of confirmed human CE was higher in Narenhebuke (2.7%, 49/1844) than in Kekergash (0.9%, 17/1861; P < 0.01). Within each community there was no significant difference of CE prevalence between the Kazakh and Mongolian groups, although Han Chinese exhibited twice the rate of CE (4.9%) in Narenhebuke compared to the dominant Mongolian population. For each community, human CE prevalence increased with age and there was a greater risk associated with the practice of home slaughter of livestock. Dogs were screened for Echinococcus granulosus infection and re-infection levels using a highly specific coproantigen test. The proportion of dogs with positive coproantigen tests was significantly higher in Narenhebuke (36.0%, 50/139) compared to Kekergash (17.8%, 16/90). In Narenhebuke the re-infection levels of dogs, as determined by coproantigen positivity, were higher in the winter quarters (49.4%, 39/79) compared to the summer quarters (18.3%, 11/60; P < 0.01). Furthermore, coproantigen re-test positivity was 25% at 3 months and 29.2% at 7 months. Highest dog coproantigen positivity was obtained over the winter period.

Analysis of immunoglobulin G subclass in the serum antibody responses of alveolar echinococcosis patients after surgical treatment and chemotherapy as an aid to assessing the outcome

Immunoglobulin G (IgG) subclass-specific antibody responses were evaluated for the follow-up of alveolar echinococcosis (AE) patients. Seventy-four sequentially collected sera from 25 Chinese and French AE cases who underwent surgery including hepatectomy, liver transplant and/or chemotherapy were analysed quantitatively and qualitatively during the clinical follow-up period. These AE patients were classified in 4 groups--cured, improved, stabilized, or aggravated. Serum antibody levels of the subclasses IgG1 and IgG4 were significantly higher in the AE patients than in healthy controls. IgG1 and IgG4 isotypes in AE patients were the most sensitive IgG antibody response in an enzyme-linked immunosorbent assay (ELISA) and in binding to antigens of 44kDa, 35kDa, 21kDa and 17.5kDa in an Echinococcus multilocularis protoscolex extract after Western blotting. In AE cases classed as cured or improved, IgG subclass antibody levels tended to decrease earlier than total IgG levels, especially IgG4 antibody levels which became negative within one year after successful treatment. IgG4 antibody levels also decreased in most of the improved cases. Increasing or unchanged levels of IgG4 and IgG1 antibodies were demonstrated in both stabilized and aggravated AE cases using both ELISA and immunoblot assays. Reappearance of specific IgG4 antibodies was a strong indication of recurrence, especially in liver transplant patients. Combined quantitative and qualitative assessment of IgG1 and IgG4 antibodies may be potentially useful for the serological follow-up of human AE.

The biological effects of photodynamic therapy on normal skin in mice--I. A light microscopic study

A light microscopic investigation of the biological effects of photodynamic therapy using hematoporphyrin derivative and red light irradiation has been carried out. HpD alone, even used at a dose of 50 mg/kg, did not cause histologically discernible changes. The irradiation alone used in this experiment caused only slight or moderate dilatation and congestion of blood vessels, which disappeared completely within several hours after light exposure. In the PDT treated mouse ears severe degeneration and necrosis of skin tissue occurred within 1-2 days. The importance of adequate drug and light doses and proper interval chosen for obtaining best therapeutic effects and protection of surrounding normal tissues was pointed out. The possible mechanism of the PDT action in vivo was briefly discussed.

The biological effects of photodynamic therapy on normal skin in mice--II. An electron microscopic study

In the present study it has been demonstrated that the ultrastructural changes in mouse ear skin after PDT action occurred much more distinct and earlier than those observed in the histological study. Various types of cells in the skin respond to the photodynamic action differently. The endothelial cells, fibroblasts and nerve fibers are most sensitive. In contrast, the keratinocytes and chondrocytes often remain rather well preserved after PDT treatment. The possible mechanism of PDT action was briefly discussed.