Differentiating thymoma, thymic carcinoma and lymphoma based on collagen fibre patterns with T2- and diffusion-weighted magnetic resonance imaging.

OBJECTIVES: The amount and distribution of intratumoural collagen fibre vary among different thymic tumours, which can be clearly detected with T2- and diffusion-weighted MR images. To explore the incidences of collagen fibre patterns (CFPs) among thymomas, thymic carcinomas and lymphomas on imaging, and to evaluate the efficacy and reproducibility of CFPs in differential diagnosis of thymic tumours. MATERIALS AND METHODS: Three hundred and ninety-eight patients with pathologically diagnosed thymoma, thymic carcinoma and lymphoma who underwent T2- and diffusion-weighted MR imaging were retrospectively enrolled. CFPs were classified into four categories: septum sign, patchy pattern, mixed pattern and no septum sign. The incidences of CFPs were compared among different thymic tumours, and the efficacy and reproducibility in differentiating the defined tumour types were analysed. RESULTS: There were significant differences in CFPs among thymomas, thymic squamous cell carcinomas (TSCCs), other thymic carcinomas and neuroendocrine tumours (OTC&NTs) and thymic lymphomas. Septum signs were found in 209 (86%) thymomas, which differed between thymomas and any other thymic neoplasms (all p < 0.005). The patchy, mixed patterns and no septum sign were mainly seen in TSCCs (80.3%), OTC&NTs (78.9%) and thymic lymphomas (56.9%), respectively. The consistency of different CFP evaluation between two readers was either good or excellent. CFPs achieved high efficacy in identifying the thymic tumours. CONCLUSION: The CFPs based on T2- and diffusion-weighted MR imaging were of great value in the differential diagnosis of thymic tumours. KEY POINTS: • Significant differences are found in intratumoural collagen fibre patterns among thymomas, thymic squamous cell carcinomas, other thymic carcinomas and neuroendocrine tumours and thymic lymphomas. • The septum sign, patchy pattern, mixed pattern and no septum sign are mainly seen in thymomas (86%), thymic squamous cell carcinomas (80.3%), other thymic carcinomas and neuroendocrine tumours (79%) and thymic lymphomas (57%), respectively. • The collagen fibre patterns have high efficacy and reproducibility in differentiating thymomas, thymic squamous cell carcinomas and thymic lymphomas.

Can the low and high b-value distribution influence the pseudodiffusion parameter derived from IVIM DWI in normal brain?

BACKGROUND: Our study aims to reveal whether the low b-values distribution, high b-values upper limit, and the number of excitation (NEX) influence the accuracy of the intravoxel incoherent motion (IVIM) parameter derived from multi-b-value diffusion-weighted imaging (DWI) in the brain. METHODS: This prospective study was approved by the local Ethics Committee and informed consent was obtained from each participant. The five consecutive multi-b DWI with different b-value protocols (0-3500 s/mm2) were performed in 22 male healthy volunteers on a 3.0-T MRI system. The IVIM parameters from normal white matter (WM) and gray matter (GM) including slow diffusion coefficient (D), fast perfusion coefficient (D*) and perfusion fraction (f) were compared for differences among defined groups with different IVIM protocols by one-way ANOVA. RESULTS: The D* and f value of WM or GM in groups with less low b-values distribution (less than or equal to 5 b-values) were significantly lower than ones in any other group with more low b-values distribution (all P <  0.05), but no significant differences among groups with more low b-values distribution (P > 0.05). In addition, no significant differences in the D, D* and f value of WM or GM were found between group with one and more NEX of low b-values distribution (all P > 0.05). IVIM parameters in normal WM and GM strongly depended on the choice of the high b-value upper limit. CONCLUSIONS: Metrics of IVIM parameters can be affected by low and high b value distribution. Eight low b-values distribution with high b-value upper limit of 800-1000 s/mm2 may be the relatively proper set when performing brain IVIM studies.

Predicting pathological subtypes and stages of thymic epithelial tumors using DWI: value of combining ADC and texture parameters.

OBJECTIVES: To explore the value of combining apparent diffusion coefficients (ADC) and texture parameters from diffusion-weighted imaging (DWI) in predicting the pathological subtypes and stages of thymic epithelial tumors (TETs). METHODS: Fifty-seven patients with TETs confirmed by pathological analysis were retrospectively enrolled. ADC values and optimal texture feature parameters were compared for differences among low-risk thymoma (LRT), high-risk thymoma (HRT), and thymic carcinoma (TC) by one-way ANOVA, and between early and advanced stages of TETs were tested using the independent samples t test. Receiver operating characteristic (ROC) curve analysis was performed to determine the differentiating efficacy. RESULTS: The ADC values in LRT and HRT were significantly higher than the values in TC (p = 0.004 and 0.001, respectively), also in early stage, values were significantly higher than ones in advanced stage of TETs (p < 0.001). Among all texture parameters analyzed in order to differentiate LRT from HRT and TC, the V312 achieved higher diagnostic efficacy with an AUC of 0.875, and combination of ADC and V312 achieved the highest diagnostic efficacy with an AUC of 0.933, for differentiating the LRT from HRT and TC. Furthermore, combination of ADC and V1030 achieved a relatively high differentiating ability with an AUC of 0.772, for differentiating early from advanced stages of TETs. CONCLUSIONS: Combination of ADC and DWI texture parameters improved the differentiating ability of TET grades, which could potentially be useful in clinical practice regarding the TET evaluation before treatment. KEY POINTS: • DWI texture analysis is useful in differentiating TET subtypes and stages. • Combination of ADC and DWI texture parameters may improve the differentiating ability of TET grades. • DWI texture analysis could potentially be useful in clinical practice regarding the TET evaluation before treatment.

Exon sequencing reveals that missense mutation of PBX1 gene may increase the risk of non-syndromic cleft lip/palate.

OBJECTIVE: Non-syndromic oral cleft (NSOC) is one of the most common multifactorial birth defects. A previous animal study showed PBX1 gene knockout mice consequently exhibited complete cleft lip/palate (CL/P). However, little is known about the association between PBX1 and NSOC in humans. This study investigated the role of the PBX1 gene in NSOC in the Han Chinese population. METHODS: In all, 287 NSOCs were recruited for this study. First, exons in the PBX1 gene were sequenced among 50 non-syndromic cleft lip and palate cases to screen for variations by the Sanger sequencing method. Then, we selected four SNPs to replicate among 237 NSOC trios and analyzed the data by using TDT and parent of origin effect methods. RESULTS: Exon sequencing identified six variants of the PBX1 gene. Among them, four variants were common variants. TDT analysis revealed allele G at rs2275558 and allele T at rs3835581 were over-transmitted in NSCL/P (P=0.039 and 0.038, respectively), which could increase the risk for NSCL/P. Parent of origin effect analysis indicated that allele G at rs2275558 was paternally over-transmitted for NSCL/P (P=0.0091). CONCLUSION: This is the first report that the PBX1 gene is associated with NSCL/P, which indicates that it is a promising candidate gene for NSCL/P.

NTN1 gene was risk to non-syndromic cleft lip only among Han Chinese population.

OBJECTIVE: Genome-wide association studies (GWAS) found NTN1, NOG and the region between CREBBP and ADCY9 were risks to non-syndromic cleft lip with or without cleft palate (NSCL/P). However, the association of single nucleotide polymorphisms (SNPs) in these genes with NSCL/P in Western China is unknown. SUBJECTS AND METHODS: We selected seven SNPs in NTN1, NOG and between CREBBP and ADCY9, and then performed transmission disequilibrium test (TDT), parent-of-origin effect and sliding window haplotype analysis to test the associations among 302 NSCL/P case-parent trios from Western Han Chinese. RESULTS: We found allele G at rs4791774 in NTN1 was significantly overtransmitted among non-syndromic cleft lip only (NSCLO) (p = 0.0067, OR = 1.79, 95% CI: 1.17-2.74); rs4791774 and rs9915089 tightly linked with each other among NSCL/P (D' = 0.87, r2  = 0.67) and haplotypes carrying the risk allele G at rs4791774 were always found to be overtransmitted from parents to cases. Motif analysis indicated that allele G at rs4791774 could greatly alter the affinity of Myc_disc7, so allele G at rs4791774 in NTN1 might modulate C-MYC transcription to participate in the aetiology of NSCLO. CONCLUSIONS: Our study suggested allele G at rs4791774 in NTN1 gene is risk of NSCLO, which could greatly increase the risk to have a baby with cleft.

Usefulness of Volume Perfusion Computed Tomography in Differentiating Histologic Subtypes of Thymic Epithelial Tumors.

PURPOSE: This study aimed to evaluate the usefulness of volume perfusion computed tomography (VPCT) parameters in differentiating the World Health Organization subtypes of thymic epithelial tumors. MATERIALS AND METHODS: This study was approved by the local ethics committee, and informed written consent was obtained. Fifty-one thymic epithelial tumor patients confirmed by histopathological analysis underwent conventional CT and a 48-second VPCT scan of the tumor bulk before any treatment. The VPCT parameters (blood volume [BV], blood flow [BF], mean transit time [MTT], and permeability [PMB]) based on volume of interest (VOI) or region of interest (ROI) were compared for differences among low-risk thymomas (LRTs; types A, AB, and B1), high-risk thymomas (HRTs; types B2 and B3) and thymic carcinomas (TCs) by one-way analysis of variance. RESULTS: The BVVOI, PMBVOI, BVROI, and PMBROI values in LRT were significantly higher than the values from HRT and thymic carcinoma (BVVOI: 13.75, 6.17, and 5.48 mL/100 mL; PMBVOI: 22.47, 9.56, and 13.37 mL/100 mL/min; BVROI: 14.75, 6.87, and 6.06 mL/100 mL; PMBROI: 24.05, 9.79, and 15.63 mL/100 mL/min, respectively; all P < 0.05/3). However, the BFVOI, MTTVOI, BFROI, and MTTROI values did not differ between LRT and HRT or thymic carcinoma groups (P > 0.05/3). CONCLUSIONS: These results suggest that VPCT could be useful in differentiating LRTs from HRTs and TCs preoperatively.

Incidence and clinical variable inter-relationships of thymic epithelial tumors in northwest China.

BACKGROUND: Thymic epithelial tumors (TETs) are the most common primary thymus tumors, but neither the possible ethnical/regional differences in the incidence of TETs nor the inter-relationships among the clinical variables has been revealed in northwest China. METHODS: A retrospective chart review was performed among pathologically confirmed TET patients from January 2004 to December 2015 in a tertiary general hospital of northwest China and the incidence, clinical features and the inter-relationships among clinical variables were analyzed. RESULTS: A total of 603 pathologically confirmed TETs patients (age range, 5-78 years; 308 males) were enrolled and the most common lesion location was anterior mediastinum (98.5%), among them, 192 (31.8%) had myasthenia gravis (MG). Twenty-six (5.7%), 112 (24.6%), 83 (18.2%), 137 (30.1%), 74 (16.3%), and 23 (5.1%) patients fell into the World Health Organization (WHO) type A, AB, B1, B2, B3 and thymic carcinoma (TC), respectively. The incidence of TETs was slightly higher in the female population and the age group of 40-60 years old. In addition, MG predominantly coexisted with WHO types A-B3 TETs and the TETs with MG were smaller than those without MG. The correct diagnosis rates were 42.3% (77 out of 182), 61.1% (127 out of 208), 89.3% (250 out of 280) and 75.0% (3 out of 4) for chest X-ray, non-contrast computed tomography (CT), contrast CT scan and magnetic resonance imaging (MRI), respectively. CONCLUSIONS: Distinct gender and age differences exist in the incidence of TETs and the A-B3 TETs are closely related with MG. Contrast CT scan plays more important role in diagnosing TETs.

Intravoxel incoherent motion diffusion-weighted MR imaging parameters predict pathological classification in thymic epithelial tumors.

We evaluated the performance of intravoxel incoherent motion (IVIM) parameters for preoperatively predicting the subtype and Masaoka stage of thymic epithelial tumors (TETs). Seventy-seven patients with pathologically confirmed TETs underwent a diffusion weighted imaging (DWI) sequence with 9 b values. Differences in the slow diffusion coefficient (D), fast perfusion coefficient (D*), and perfusion fraction (f) IVIM parameters, as well as the multi b-value fitted apparent diffusion coefficient (ADCmb), were compared among patients with low-risk (LRT) and high-risk thymomas (HRT) and thymic carcinomas (TC), and between early stage (stages I and II) and advanced stage (stages III and IV) TET patients. ADCmb, D, and D* values were higher in the LRT group than in the HRT or TC group, but did not differ between the HRT and TC groups. The mean ADCmb, D, and D* values were higher in the early stage TETs group than the advanced stage TETs group. The f values did not differ among the groups. These results suggest that IVIM DWI could be used to preoperatively predict subtype and Masaoka stage in TET patients.

New insights from GWAS for the cleft palate among han Chinese population

BACKGROUND: Genome wide association studies (GWAS) already have identified tens of susceptible loci for nonsyndromic cleft lip with or without cleft palate (NSCL/P). However, whether these loci associated with nonsyndromic cleft palate only (NSCPO) remains unknown. MATERIAL AND METHODS: In this study, we replicated 38 SNPs (Single nucleotide polymorphisms) which has the most significant p values in published GWASs, genotyping by using SNPscan among 144 NSCPO trios from Western Han Chinese. We performed the transmission disequilibrium test (TDT) on individual SNPs and gene-gene (GxG) interaction analyses on the family data; Parent-of-Origin effects were assessed by separately considering transmissions from heterozygous fathers versus heterozygous mothers to affected offspring. RESULTS: Allelic TDT results showed that T allele at rs742071 (PAX7) (p = 0.025, ORtransmission=3.00, 95%CI: 1.09- 8.25) and G allele at rs2485893 (10kb 3' of SYT14) were associated with NSCPO (p = 0.0036, ORtransmission= 0.60, 95%CI: 0.42-0.85). Genotypic TDT based on 3 pseudo controls further confirmed that rs742071 (p-value=0.03, ORtransmission=3.00, 95%CI: 1.09-8.25) and rs2485893 were associated with NSCPO under additive model (p-value= 0.02, ORtransmission= 0.66, 95%CI: 0.47-0.92). Genotypic TDT for epistatic interactions showed that rs4844913 (37kb 3' of DIEXF) interacted with rs11119388 (SYT14) (p-value=1.80E-08) and rs6072081 (53kb 3' of MAFB) interacted with rs6102085 (33kb 3' of MAFB) (p-value=3.60E-04) for NSCPO, suggesting they may act in the same pathway in the etiology of NSCPO. CONCLUSIONS: In this study, we found that rs742071 and rs2485893 were associated NSCPO from Han Chinese population; also, interactions of rs4844913:rs11119388 and rs6072081:rs6102085 for NSCPO were identified, genegene interactions have been proposed as a potential source of the remaining heritability, these findings provided new insights of the previous GWAS

Rs12941170 at SOX9 gene associated with orofacial clefts in Chinese.

OBJECTIVE: Non-syndromic orofacial cleftings (NSOCs) are considered as complex trait, which results from genetic and/or environmental modifiers. Current findings could only explain small portion of the NSOCs. SOX9 gene plays an important role during craniofacial development in animal models and the Pierre Robin sequence (PRS). However, its role in non-syndromic clefts remains unknown. DESIGN: In this study, we selected eight SNPs in and around SOX9 gene to make maximum coverage, and genotyped them by using RFLP-PCR and ligase detection reaction (LDR) methods to test its associations among 151 NSOCs (53 NSCLP, 52 NSCLO and 46 NSCPO) from Western Han Chinese population. RESULTS: Allelic TDT results showed that G allele at rs12941170 of SOX9 was under-transmitted among NSOCs (p=0.00014, OR=0.55 and 95%CI: 0.40-0.75), which could indicate that the G allele is protective against NSOCs; parent-of-origin effect analysis showed that G allele at rs12941170 was maternally under-transmitted (p=0.002), while there was no statistically difference between the maternal and paternal transmission of it. To test if the adjacent SNPs travel together from parents to the affected individual, we carried out the sliding window haplotype analysis, it is interesting to find that the haplotypes carrying the G allele at rs12941170 also was under-transmitted for NSOCs, NSCL/P, NSCLP and NSCPO (lowest p=0.00033). CONCLUSIONS: This study suggested that G allele at rs12941170 was protective, which could decrease the risk for NSOCs from Western Han Chinese population, and it will provide new reference for future research and genetic counseling in NSOCs.

[Therapeutic effect of photodynamic treatment for psoriasis vulgaris in guinea pigs].

OBJECTIVE: To observe the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for treating psoriasis vulgaris in guinea pigs. METHODS: Experimental psoriasis vulgaris was induced in guinea pigs by application of 5% propranolol on the ear skin. After dressing of the skin lesion with 20% ALA solution for 4 h, the lesions were irradiated with a semiconductor laser at the wavelength of 635 nm and energy density of 12 J/cm(2). The guinea pigs were divided into control group, ALA only group, light only group, single ALA-PDT treatment group and twice ALA-PDT treatment group. In each group, gross observation and biopsy of the skin lesions was conducted on days 7, 14, 21 and 28 after the treatment. RESULTS: In terms of gross observation of the lesion, epidermal thickness and proliferating cell nuclear antigen (PCNA) expression, ALA-PDT treatment showed obvious therapeutic effect on the skin lesion, and two treatment sessions resulted in better effect than a single session. CONCLUSION: ALA-PDT can cure psoriasis vulgaris lesions characterized by abnormal epidermal proliferation in guinea pigs, and multiple treatment sessions can achieve better effects.