Radiomics-based distinction of small (≤2 cm) hepatocellular carcinoma and precancerous lesions based on unenhanced MRI

AIM

To assess the feasibility of a radiomics model based on unenhanced magnetic resonance imaging (MRI) to differentiate small hepatocellular carcinoma (S-HCC) (≤2 cm) and pre-hepatocellular carcinoma (Pre-HCC).

MATERIALS AND METHODS

One hundred and fourteen histopathologically confirmed 114 hepatic nodules were analysed retrospectively. All patients had undergone MRI before surgery using a 3 T MRI system. Each nodule was segmented on unenhanced MRI sequences (T1-weighted imaging [T1] and T2WI with fat-suppression [FS-T2]). Radiomics features were extracted and the optimal features were selected using the least absolute shrinkage and selection operator (LASSO). The support vector machine (SVM) was used to establish the radiomics model. One abdominal radiologist performed the conventional qualitative analysis for classification of S-HCC and Pre-HCC. The diagnostic performances of the radiomics and radiologist models were evaluated using receiver operating characteristic (ROC) analysis.

RESULT

Radiomics features (n=1,223) were extracted from each sequence and the optimal features were selected from T1, FS-T2, and T1+FS-T2 to construct the radiomics models. The radiomics model based on T1+FS-T2 showed the best performance among the three models, with areas under the ROC curves (AUCs) of 0.95 (95 % confidence interval [CI], 0.875-0.986) and 0.942 (95 % CI, 0.775-0.985), accuracies of 86 % and 88.5 %, sensitivities of 94.12 % and 100 %, and specificities of 85.48 % and 85.19 %, respectively. The radiomics model on FS-T2 showed better performance on a single sequence than that of the T1-based model. The diagnostic performance for the radiomic model was significantly higher than that for the radiologist (AUC = 0.518, p<0.05).

CONCLUSION

This study suggested that a radiomics model based on unenhanced MRI may serve as a feasible and non-invasive tool to classify S-HCC and Pre-HCC.

[Expression of endosialin in human hypertrophic scars and its regulation on fibroblast phenotype]

Objective: To explore the expression of endosialin, i.e., CD248 in human hypertrophic scars (HSs) and its regulatory effect on the phenotype of hypertrophic scar fibroblasts (HSFs). Methods: The method of experimental research was used. From March to May, 2023, 3 pediatric patients with HS were admitted to the Department of Burns and Cutaneous Surgery of the First Affiliated Hospital of Air Force Medical University, including 2 females and 1 male, aged one year ten months to two years. The HS tissue resected during the surgery and the remaining full-thickness skin graft, i.e., normal skin tissue after full-thickness skin grafting were collected from the aforementioned pediatric patients for subsequent experiments. Using the aforementioned two types of tissue, the histological structures were observed by hematoxylin-eosin staining, collagen distribution was observed by Masson staining, and the expression of CD248 was observed and measured by immunohistochemical staining. The primary HSFs were isolated from HS tissue using explant culture technique, and the 3rd to 5th passages of HSFs were used in subsequent experiments. According to the random number table, HSFs were divided into immunoglobulin G78 (IgG78)-treated group and IgG control group, which were treated with 200 nmol/L human CD248 monoclonal antibody IgG78 and human IgG control antibody for 24 h, respectively. The mRNA expressions of collagen type Ⅰ (Col Ⅰ) and α-smooth muscle actin (α-SMA) in HSFs were measured by real-time fluorescence quantitative reverse transcription polymerase chain reaction, the protein expressions of Col Ⅰ and α-SMA in HSFs were detected by Western blotting, and the intracellular location and protein expressions of Col Ⅰ and α-SMA were detected by immunofluorescence method. The number of samples in each experiment was 3. Data were statistically analyzed with paired sample t test and independent sample t test. Results: Compared with those in normal skin tissue, the epidermis and dermis in HS tissue were significantly thicker, with massive accumulation and disordered arrangement of collagen in the dermis. The expression of CD248 in HS tissue was significantly upregulated compared with that in normal skin tissue (t=5.29, P<0.05). At post treatment hour 24, the mRNA expressions of Col Ⅰ and α-SMA of HSFs in IgG78-treated group were 0.39±0.05 and 0.56±0.09, respectively, which were significantly lower than 1.00±0.07 and 1.00±0.08 in IgG control group, respectively (with t values of 11.87 and 6.49, respectively, P values all <0.05). The protein expressions of Col Ⅰ and α-SMA of HSFs in IgG78-treated group were 0.617±0.011 and 0.67±0.14, respectively, which were significantly lower than 1.259±0.052 and 1.23±0.16 in IgG control group, respectively (with t values of 20.92 and 4.52, respectively, P values all <0.05). At post treatment hour 24, immunofluorescence staining showed that Col Ⅰ and α-SMA mainly located in the cytoplasm of HSFs in the two groups, and the protein expressions of Col Ⅰ and α-SMA of HSFs in IgG78-treated group were obviously downregulated compared with those in IgG control group. Conclusions: The expression of CD248 is significantly upregulated in human HS. Targeted blockade of CD248 can significantly inhibit the collagen synthesis by HSFs and the transdifferentiation of HSFs into myofibroblasts.

CRISPR/Cas9-mediated gene editing of the let-7 seed sequence improves silk yield in the silkworm, Bombyx mori

Body size and silk protein synthesis ability are two crucial aspects of artificial selection in silkworm breeding; however, the role of genes in both pathways remains unknown. To determine whether let-7 microRNA could regulate larval development and silk gland growth simultaneously, we designed a guide RNA to edit let-7 using the CRISPR/Cas9 system. The indels predominantly appeared in the let-7 seed region, and the vast majority of the mutations were small-fragment deletions. Loss of let-7 function prolonged the fifth larval period, and substantially increased body weight during the wandering stage, but it resulted in developmental arrest during the pupal-moth transition. let-7 systemic knock down promoted silk gland growth and increased silk yield by >50 %, with efficiency significantly higher than in tissue-specific edited individuals. Hormone signaling and cell cycle pathway genes were activated in different patterns in the body and silk gland, implying that let-7 may regulate different target genes to play role in tissue growth. In summary, we first report that conditional knock down let-7 promoting the simultaneous growth of body and silk gland, greatly improve silk yield in the silkworm.

Far-infrared transparent conductors

The long-standing challenge in designing far-infrared transparent conductors (FIRTC) is the combination of high plasma absorption edge (λ_p) and high conductivity (σ). These competing requirements are commonly met by tuning carrier concentration or/and effective carrier mass in a metal oxide/oxonate with low optical dielectric constant (ε_opt = 2-7). However, despite the high σ, the transparent band is limited to mid-infrared (λ_p < 5 μm). In this paper, we break the trade-off between high σ and λ_p by increasing the "so-called constant" ε_opt that has been neglected, and successfully develop the material family of FIRTC with ε_opt > 15 and λ_p > 15 μm. These FIRTC crystals are mainly octahedrally-coordinated heavy-metal chalcogenides and their solid solutions with shallow-level defects. Their high ε_opt relies on the formation of electron-deficiency multicenter bonds resulting in the great electron-polarization effect. The new FIRTC enables us to develop the first "continuous film" type far-infrared electromagnetic shielder that is unattainable using traditional materials. Therefore, this study may inaugurate a new era in far-infrared optoelectronics.

Identification and functional study of fhx-L1, a major silk component in Bombyx mori

The silkworm cocoon was composed of fibroins, sericins, protease inhibitors, and proteins of unknown function. In this study, we focused on fhx-L1 (fibrohexamerin-like1), which was the homolog of fibroin fhx (fibrohexamerin). We identified 154 fhx family genes in 44 Lepidoptera insects, and seven fhx-Ls were found in Bombyx mori. Fhx-L1 was the most abundant of these proteins in silk and was specifically expressed in the silk gland. Immunofluorescence analysis showed that fhx-L1 was secreted into the whole sericin layers, similar to sericin1 (ser1). Western blotting revealed that the fhx-L1 protein contains N-linked oligosaccharide chains. CRISPR/Cas9-mediated gene editing was used to generate a homozygous mutant of fhx-L1 (fhx-L1^KO). The cocoon of fhx-L1^KO was larger and fluffier than that of the wild-type (WT), which was attributed to the lower adhesion between silk fibers. We also found that the content of β-sheet in the mutant silk was lower than in the WT silk, which resulted in further deterioration of the mechanical properties of the fhx-L1^KO silk. Our study revealed the properties and function of fhx-L1 as a major structural component in silk. Then, our study provided a potential insight for in-depth study of silk protein function.

Analysis of histomorphometric and proteome dynamics inside the silk gland lumen of Bombyx mori revealed the dynamic change of silk protein during the molt stage

Silkworms spin different silks at different growth stages for specific purposes. The silk spun before the end of each instar is stronger than that at the beginning of each instar and cocoon silk. However, the compositional changes in silk proteins during this process are unknown. Consequently, we performed histomorphological and proteomic analyses of the silk gland to characterize changes from the instar end to the next instar beginning. The silk glands were collected on day 3 of third- and fourth-instar larvae (III-3 and IV-3) and the beginning of fourth-instar larvae (IV-0). Proteomic analysis identified 2961 proteins from all silk glands. Silk proteins P25 and Ser5 were significantly more abundant in III-3 and IV-3 than in IV-0, and many cuticular proteins and protease inhibitors increased significantly in IV-0 compared with III-3 and IV-3. This shift may cause mechanical property differences between the instar end and beginning silk. Using section staining, qPCR, and western blotting, we found for the first time that silk proteins were degraded first and then resynthesized during the molting stage. Furthermore, we revealed that fibroinase mediated the changes of silk proteins during molting. Our results provide insights into the molecular mechanisms of silk proteins dynamic regulation during molting.

Rational Regulation of Reducibility and Acid Site on Mn-Fe-BTC to Achieve High Low-Temperature Catalytic Denitration Performance

Selective catalytic reduction with ammonia is the mainstream technology of flue gas denitration (de-NO_x). The reducibility and acid site are two important factors affecting the de-NO_x performance, and effective regulation between them is the key to obtain a highly efficient de-NO_x catalyst. Herein, a series of Mn-Fe-BTC with different ratios of Mn and Fe are synthesized, among which 2Mn-1Fe-BTC with 2:1 molar ratio of Mn and Fe has excellent low-temperature (LT) de-NO_x performance (above 90% NO conversion between 60 and 270 °C) and good tolerance to H₂O and SO₂ poisoning (88% NO conversion at 150 °C with 100 ppm of SO₂ and/or 6% H₂O). It is revealed that the reducibility properties and acid sites of Mn-Fe-BTC can be flexibly tuned by the ratio of Mn and Fe. The difference in electronegativity between Fe and Mn leads to the redistribution of valence electrons, which enables the controllable reducibility of Mn-Fe-BTC. Furthermore, different amounts of Mn and Fe lead to different electron transport, which determines the type and number of acid sites. The synergistic effect of Mn and Fe endows Mn-Fe-BTC with enhanced surface molecular adsorption capacity and enables the catalyst to selectively chemisorb NH₃ and NO at different active sites. This research provides guidance for the flexible regulation of reducibility and acid site of LT de-NO_x catalyst.

Efficacy and Safety of Probiotics in Geriatric Patients with Constipation: Systematic Review and Meta-Analysis

BACKGROUND

Probiotics may be an effective alternative to traditional drug therapy for constipation in the elderly.

OBJECTIVE

To assess the efficacy and safety of probiotics in managing constipation among the elderly.

METHODS

Eight databases were queried for randomized controlled trials (RCTs) investigating probiotics' efficacy in addressing constipation among the elderly until January 2023. The meta-analysis was conducted employing R software version 4.2.2. The Cochrane risk of bias tool was utilized to evaluate the risk of bias, and the GRADE approach was employed to assess the credibility of the evidence concerning the efficacy of probiotics in treating constipation in older individuals.

RESULTS

A total of six RCTs involving 444 patients were included. Two studies were rated as low risk of bias. The meta-analysis findings revealed that probiotics, when compared to a placebo, led to an increase in stool frequency (MD = 1.02,95% CI [0.21, 2.07], p<0.05, very low quality), the probiotic group exhibited a notable impact on ameliorating symptoms associated with constipation (OR = 11.28, 95%CI [7.21, 17.64], p < 0.05, very low quality), no significant disparities were observed in terms of efforts to evacuate, manual maneuvers, and the incidence of adverse events (p>0.05).

CONCLUSION

The available evidence indicates a degree of uncertainty, ranging from low-to-very low, suggesting the efficacy of probiotics in augmenting bowel frequency and ameliorating constipation-related symptoms among elderly patients with constipation. Nevertheless, given the quality of the studies included, it is advisable to conduct further well-designed investigations with substantial sample sizes to substantiate the findings of this study.

Programmed Death of Microglia in Alzheimer's Disease: Autophagy, Ferroptosis, and Pyroptosis

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, amyloid-β (Aβ) plaques and the formation of neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau. Increasing evidence has demonstrated that the damage of cell plays an important role in AD. Cell death is a critical phenomenon for physiological functions, which promotes AD pathogenesis. Programmed cell death, including necroptosis, pyroptosis, autophagy, and ferroptosis, have been discovered that have unique biological functions and pathophysiological characteristics. Here, we review the available evidence detailing the mechanisms of programmed microglial death, including pyroptosis, autophagy, and ferroptosis. We also highlight the role of programmed death of microglia during the process of AD and focus on the connection between the disease and cell death.

Insights into the structure and composition of mineralized hard cocoons constructed by the oriental moth, Monema (Cnidocampa) flavescens Walker

Animals widely use minerals and organic components to construct biomaterials with excellent properties, such as teeth, bones, molluscan shells and eggshells. The larvae of the oriental moth, Monema (Cnidocampa) flavescens Walker, secrete silk proteins that combine closely with calcareous minerals to construct a hard cocoon, which is completely different from the mineral-free Bombyx mori cocoon. The cocoons of oriental moths are likely to be the hardest among the cocoons constructed by insect species. The cocoons of oriental moths were found to be mainly composed of calcium oxalates and Asx/Ser/Gly-rich cocoon proteins, but the types of calcium oxalates and cocoon proteins remain to be elucidated. In this study, we provide an in-depth explanation of the inorganic and organic components in the oriental moth cocoon. Microscopy and imaging technologies revealed that the cocoon is composed of mineral crystals, silk fibers and other organic matter. X-ray diffraction and infrared spectral analyses showed that the mineral crystals in the oriental moth cocoon were mainly CaC₂H₂O₄·H₂O. ICP-OES analysis suggested that the mineral crystals in the cocoons were mainly CaC₂H₂O₄·H₂O. LC-MS/MS-based proteomics allowed us to identify 467 proteins from the oriental moth cocoon, including 252 uncharacterized proteins, 87 enzymes, 36 small molecule binding proteins, and 5 silk proteins. Among the uncharacterized proteins, 25 of which were Asn-rich proteins because they contained a high proportion of Asn residues (19.1%-41.4%). Among the top 20 cocoon proteins with the highest abundance, 9 of which were Asn-rich proteins. The qPCR was used to investigate the expression patterns of the major cocoon protein-coding genes. Three fibroins and three Asn-rich proteins were expressed only in the silk gland but not in other tissues. The expression of Asn-rich proteins in the silk gland gradually increased from the anterior silk gland to the posterior silk gland. These findings provide important references for understanding the formation mechanism and mechanical properties of mineralized hard cocoons constructed by oriental moths.

Clinical efficacy of wet dressing combined with chitosan wound dressing in the treatment of deep second-degree burn wounds: A prospective, randomised, single-blind, positive control clinical trial

To evaluate the efficacy and safety of wet dressing combined with chitosan wound dressing for deep II degree burn wounds, and provide the basis for clinical application. From October 2019 to October 2021, 80 patients with second-degree deep burn treated in the Department of burn and plastic surgery of our hospital were selected as the research objects. Patients were randomly divided into two groups. The control group (40n) was treated with wet compress, and the study group (40n) was treated with wet compress combined with chitosan wound dressing. The wound healing time, wound healing percentage and pain score were used as the effectiveness indexes, and the incidence of adverse events and serious adverse events and the detection rate of bacterial culture of wound exudates were used as the safety indexes. The efficacy and safety of the two groups were compared. The wound healing time of the study group (19.53 ± 2.74 days) was shorter than that of the control group (24.78 ± 4.86 days), the difference was significant (t = 3.571, P = 0.015). The percentage of wound healing at the 14th after treatment in the study group was higher than that in the control group (65.00% versus 37.50%) (X²  = 6.054, P = 0.014). There was no significant difference in pain scores between the two groups at each time point. The scar growth was observed 3 months after wound healing. The scar score of the study group (6.00 ± 0.98) was lower than that of the control group (8.77 ± 1.19) (t = 2.571, P = 0.031). The positive rate of wound secretion culture on the 7th and 14th day was statistically significant (X²  = 4.528, P = 0.033; X²  = 6.646, P = 0.010), and the study group was lower than the control group (29.03% versus 81.82%; 8.11% versus 42.86%). There was no significant difference in treatment cost between the study group and the control group (1258.7 ± 223.6 versus 1248.9 ± 182.3) (t = 1.571, P = 0.071). No adverse events or serious adverse events occurred in both groups. Chitosan wound dressing can significantly shorten the time of wound healing and reduce wound pain and wound infection in patients with deep second-degree burns. And it can effectively improve the situation of scar hyperplasia, which is worthy of clinical application.

Identification and characterization of sericin5 reveals non-cocoon silk sericin components with high β-sheet content and adhesive strength

Sericins are glue proteins on the surface of silk fibers. Four sericins have been characterized in silkworm, namely sericin1 (Ser1), sericin2 (Ser2), sericin3 (Ser3), and sericin4 (Ser4). In this study, we report a novel sericin, sericin5 (Ser5), which exists only in non-cocoon silk. We describe the sequence, exon-intron structure, and translation products of Ser5 in Bombyx mori. The Ser5 gene is approximately 22-kb long and comprises 16 exons. Ser5 protein has a size of 260 kDa, as determined by SDS-PAGE, western blot, and LC-MS/MS. Immunofluorescence analysis revealed that Ser5 co-localizes with Ser1 in the sericin layer. The expression pattern of Ser5 was detected at the transcriptional and translational levels. We systematically analyzed and compared the amino acid composition, repeat regions, and hydrophilicity of silkworm sericins. Morphological observations showed that non-cocoon silk had more sericin than cocoon silk. Circular dichroism spectra revealed that non-cocoon silk sericin contained more β-sheet structures than cocoon silk sericin. In addition, we found that the hydrophilicity and adhesive strength of native sericin increases gradually from the inner layer to the outer layer. This research enhances our understanding of various sericins from cocoon silk and non-cocoon silk with regard to their expression patterns, hydrophilicity, secondary structure and adhesive performances. STATEMENT OF SIGNIFICANCE: : Sericin is a natural biomaterial with diverse biological properties, which has long been used as tissue engineering and biomedical applications. However, the composition and distribution of sericins in different kinds of silk are still uncertain, and the properties difference between sericins have not yet been reported. Our study makes a significant contribution to the literature as it identifies the sequence, composition, hydrophilicity and adhesive property of sericins. Moreover, it provides key insights into the structure-function and function-distribution relationships associated with sericins. We believe that this study will arouse the interest to the readership of your journal as it identifies the new complete sequence of sericin and revealed the composition and properties of sericin, thus highlighting their future potentials applications in both the biomaterial and technical fields.

Analysis of the Effect of Wound-Edge Microgranular Skin Grafting in the Treatment of Various Small Wounds

Objective

To explore the clinical effect of wound edge microgranular skin grafting in the treatment of various small wounds.

Methods

From September 2018 to September 2021, Yueqing people's Hospital of Wenzhou City, Zhejiang Province collected and recorded the data of 12 patients with chronic wounds and third degree burns. The method of skin grafting with particles at the edge of the wound was used to graft skin on the wound. Scar evaluation scale was used to evaluate the wound. The patients were followed up for 12 months. The preoperative and postoperative data, scar index and patient satisfaction after healing were recorded and statistically analyzed.

Results

All patients in this group were followed up for 3-12 months, and the results showed that SCAR Scale score decreased gradually over time, with patient satisfaction ranging from 80% to 96%. The patient gradually healed, scar hyperplasia gradually improved, functional activities gradually returned to normal, clinical effect is satisfactory.

Conclusion

Microparticle skin grafting at the edge of wound avoids skin grafting at different skin donor sites. It has the characteristics of simple anesthesia, small trauma and convenient operation. This method can be considered when treating patients with chronic wounds and burns who need skin grafting.

A new approach for contralateral C7 nerve transfer via retrospinal route

Anterior and posterior approaches exist for the treatment of spinal pathologies. Anatomically, the 7th cervical spinal nerve(C7)crosses the C6-C7 intervertebral foramen bilaterally, allowing contralateral prevertebral or posterior C7 nerve transfer to be used. The advantage of the posterior rather than the anterior spinal approach is that it does not require retraction of important blood vessels, nerves, or other structures. In this paper, we describe transfer of the contralateral C7 nerve using a posterior approach.

Multi-band network fusion for Alzheimer's disease identification with functional MRI

INTRODUCTION

The analysis of functional brain networks (FBNs) has become a promising and powerful tool for auxiliary diagnosis of brain diseases, such as Alzheimer's disease (AD) and its prodromal stage. Previous studies usually estimate FBNs using full band Blood Oxygen Level Dependent (BOLD) signal. However, a single band is not sufficient to capture the diagnostic and prognostic information contained in multiple frequency bands.

METHOD

To address this issue, we propose a novel multi-band network fusion framework (MBNF) to combine the various information (e.g., the diversification of structural features) of multi-band FBNs. We first decompose the BOLD signal adaptively into two frequency bands named high-frequency band and low-frequency band by the ensemble empirical mode decomposition (EEMD). Then the similarity network fusion (SNF) is performed to blend two networks constructed by two frequency bands together into a multi-band fusion network. In addition, we extract the features of the fused network towards a better classification performance.

RESULT

To verify the validity of the scheme, we conduct our MBNF method on the public ADNI database for identifying subjects with AD/MCI from normal controls.

DISCUSSION

Experimental results demonstrate that the proposed scheme extracts rich multi-band network features and biomarker information, and also achieves better classification accuracy.

Male urethral diverticulum squamous cell carcinoma containing a calculus: a rare entity

Male urethral diverticula with calculi have a low incidence. It is extremely rare when the diverticulum accompanied with carcinoma. We report a case of diverticulum of the male urethra containing giant calculi which developed into squamous cell carcinoma. The patient initially presented with lower urinary tract symptoms and a hard, painless perineal mass. We believe that the process of diagnosis and treatment is of great significance in clinical practice.

[Efficacy and safety of paclitaxel liposomes compared to paclitaxel combined with platinum in concurrent chemoradiotherapy for unresectable cervical carcinoma: a Meta-analysis]

Objective: To explore the efficacy and safety of paclitaxel liposomes compared to paclitaxel with platinum in concurrent chemoradiotherapy for unresectable cervical carcinoma. Methods: SinoMed, CNKI, WanFang MED ONLINE, VIP, PubMed, MEDLINE, Cochrane Library, Embase and ClinicalTrials.gov were searched to collect the papers or clinical studies of paclitaxel liposomes and paclitaxel combined with platinum in concurrent chemoradiotherapy for unresectable cervical carcinoma from the inception to January 15th 2021 in Chinese and English. Two independent reviewers screened the literatures, extracted the data and assessed the bias of the included studies. Meta-analysis was performed using RevMan 5.4 and R software. Results: Totally 9 papers involving 666 patients with unresectable cervical carcinoma were included. The results of meta-analysis indicated that compared to paclitaxel combined with platinum in concurrent chemoradiotherapy for unresectable cervical carcinoma, paclitaxel liposomes combined with platinum exhibited superiority in near-term efficacy (complete response + partial response) [81.4%(272/334) vs 68.7%(228/332), RR=1.19; 95% CI: 1.09, 1.29, P=0.000 1]; substantially decreased the incidence rates of blood system disorders [myelosuppressio, 50.3%(168/334)vs 65.1%(216/332)], gastrointestinal disorders [34.4%(115/334) vs 55.1%(183/332)], alopecia [42.2%(94/223)vs 63.3%(140/221)], allergic reaction [11.6% (23/198)vs 27.6%(54/196), P≤0.000 1], peripheral neuritis [43.0%(52/121) vs 54.9%(67/122)], or joint and muscle pain [20.3%(16/79) vs 34.6%(28/81), P<0.050 0]. Conclusion: Compared to paclitaxel combined with platinum in concurrent chemoradiotherapy for unresectable cervical carcinoma, paclitaxel liposomes is superior in near-term efficacy, and exhibits better safety.

Adhesive property and mechanism of silkworm egg glue protein

Egg glue proteins (EGPs) are produced by female insects, which can make the eggs firmly attached to the oviposition sites, not affected by wind and rain. Although EGPs are widespread in insects, they have been rarely characterized in molecular detail. Here, the full-length sequence and secondary structure of silkworm EGP is reported. A pentapeptide motif, G-G-N/K/D-Q/E/K-Q/P, was found to repeat 346 times, forming a hydrophilic and elastic β-spiral structure in the silkworm EGP. To reveal the adhesive property and mechanism, we extracted natural EGP from silkworm colleterial gland, and expressed recombinant EGP in Escherichia coli and Pichia pastoris. The glycosylated natural EGP and recombinant EGP from P. pastoris was found to have better adhesive strength than the non-glycosylated recombinant EGP from E. coli. In addition, two transglutaminases in the colleterial gland were found to contribute to the high adhesion of EGP by catalyzing the cross-linking. This study provides important insights into the structure-function relationships associated with this protein, thereby creating new opportunities for the use of insect EGP as a biomaterial. STATEMENT OF SIGNIFICANCE: Egg glue proteins are produced by female insects, which can make the eggs firmly attached to the oviposition sites, not affected by wind and rain. However, genes encoding insect egg glue proteins have not yet been reported, and the molecular mechanism underpinning their adhesion is still unknown. Our study makes a significant contribution to the literature as it identifies the sequence, structure, adhesive property, and mechanism of silkworm egg glue protein. Furthermore, it outlines key insights into the structure-function relationships associated with egg glue proteins. We believe that this paper will be of interest to the readership of your journal as it identifies the first complete sequence of insect egg glue proteins, thereby highlighting their potentials future applications in both the biomedical and technical fields.

The mutation of SPI51, a protease inhibitor of silkworm, resulted in the change of antifungal activity during domestication

Domestication of silkworm has led to alterations in various gene expression patterns. For instance, many protease inhibitors were significantly downregulated in the domestic silkworm cocoon compared to its wild progenitor. Considering that SPI51 is the most abundant protease inhibitor in silkworm cocoons, herein, we compared the gene structures and sequences of SPI51 from B. mori (BmoSPI51) and B. mandarina (BmaSPI51). Comparing to the "RGGFR" active site in BmaSPI51, that of BmoPI51 is "KGSFP" and the C-terminal "YNTCECSCP" tail sequence is lost in the latter. To investigate the effect elicited by the active site and tail sequences on the function of SPI51, we expressed two mutated forms of BmoSPI51, namely, BmoSPI51 + tail and BmoSPI51M. BmoSPI51, BmoSPI51 + tail and BmoSPI51M were compared and found to have similar levels of inhibitory activity against trypsin. However, the BmoSPI51 + tail and BmoSPI51M proteins exhibited significantly stronger capacities to inhibit fungi growth, compared to BmoSPI51. We concluded that the specific amino acid sequence of the active site, as well as its the disulfide bond formed by C-terminal sequence in the BmaSPI51, represent the key factors responsible for its higher antifungal activity. This study provided new insights into the antifungal mechanisms elicited by protease inhibitors in the cocoons of silkworms.

Ultrafine and High-Strength Silk Fibers Secreted by Bimolter Silkworms

Ultrafine fibers are widely employed because of their lightness, softness, and warmth retention. Although silkworm silk is one of the most applied natural silks, it is coarse and difficult to transform into ultrafine fibers. Thus, to obtain ultrafine high-performance silk fibers, we employed anti-juvenile hormones in this study to induce bimolter silkworms. We found that the bimolter cocoons were composed of densely packed thin fibers and small apertures, wherein the silk diameter was 54.9% less than that of trimolter silk. Further analysis revealed that the bimolter silk was cleaner and lighter than the control silk. In addition, it was stronger (739 MPa versus 497 MPa) and more stiffness (i.e., a higher Young's modulus) than the trimolter silk. FTIR and X-ray diffraction results revealed that the excellent mechanical properties of bimolter silk can be attributed to the higher β-sheet content and crystallinity. Chitin staining of the anterior silk gland suggested that the lumen is narrower in bimolters, which may lead to the formation of greater numbers of β-sheet structures in the silk. Therefore, this study reveals the relationship between the structures and mechanical properties of bimolter silk and provides a valuable reference for producing high-strength and ultrafine silk fibers.

Kunitz-type protease inhibitor BmSPI51 plays an antifungal role in the silkworm cocoon

The protease inhibitors found in silkworm cocoons can be divided into several families, a majority of which contain serpin, TIL, or Kunitz domains. Previously, it has been reported that TIL-type protease inhibitors have antimicrobial activity. To date, however, it has not been determined whether the Kunitz-type protease inhibitor BmSPI51, the most abundant of cocoon protease inhibitors, plays an antimicrobial role. Thus, in this study, we sought to determine the biological role of BmSPI51 in silkworm cocoons. Our results obtained from real-time quantitative reverse transcription PCR and immunofluorescence analyses indicate that BmSPI51 is expressed exclusively in the silk glands during the larval fifth instar stage and is subsequently secreted into cocoon silk. Moreover, at a molar ratio of 1:1, BmSPI51 produced via prokaryotic expression exhibited inhibitory activity against trypsin and also proved to be highly stable over wide ranges of temperature and pH values. The expression of BmSPI51 was also found to be significantly upregulated in the larval fat body after infection with three species of fungi, namely, Candida albicans, Beauveria bassiana, and Saccharomyces cerevisiae. In vitro inhibition tests revealed that BmSPI51 significantly inhibited the sporular growth of all three of these fungal species. Further, results obtained from a binding assay showed that BmSPI51 binds to β-d-glucan and mannan on the surface of fungal cells. In this study, we, thus, revealed the antimicrobial activity of BmSPI51 and its underlying mechanism in silkworm, thereby contributing to our present understanding of defense mechanisms in silkworm cocoons.

Mutation Analysis of Pre-mRNA Splicing Genes PRPF31, PRPF8, and SNRNP200 in Chinese Families with Autosomal Dominant Retinitis Pigmentosa

BACKGROUND

To screen variants in pre-mRNA Splicing genes in 95 Chinese autosomal dominant retinitis pigmentosa (adRP) families.

METHODS

Clinical examination and pedigree analysis were performed. Targeted exome sequencing (TES) and / or Sanger sequencing were performed to detect the variants in genes of Splicing factors and conduct intra-familiar segregation analysis with DNA available. In silico analysis was performed to predict pathogenicity of variants in protein level and in vitro splicing assays were performed to compare splicing variants with their corresponding wildtype about their splicing effect.

RESULTS

In this study, total nine different variants were identified in PRPF31, SNRNP200, and PRPF8 respectively, including six PRPF31 variants [five novel variants 322+1G>A, c.527+2T>G, c.590T>C(p.Leu197Pro), c.1035_1036insGC (p.Pro346Argfs X18), and c.1224dupG (p.Gln409AlafsX66) plus one reported variant c.1060C>T (p.Arg354X)], a recurrent PRPF8 variant c.6930G>T (p.Arg2310Ser), two SNRNP200 variants [one heterozygous and homozygous SNRNP200 recurrent variant c.3260G>A (p.Ser1087Leu), and a reported heterozygous c.2042G>A(p.Arg681His)]. In family 20009, incomplete penetrance was observed. A novel PRPF31 missense variant c.590T>C (p.Leu197Pro) was predicted to be pathogenic in protein level via in silico analysis and in vitro splicing assay demonstrated that two novel splicing PRPF31 variants c.322+1G>A and c.527+2T>G affect splicing compared with the wildtype.

CONCLUSIONS

In our studies, RP-causing variants of pre-mRNA Splicing genes (PRPF31, PRPF8 and SNRNP200) were identified in nine of the ninety-five adRP families respectively, which extend the spectra of RP variant and phenotype. And we provide the first example that SNRNP200-related RP can be caused by both heterozygous and homozygous variants of this gene.

Functional analysis and characterization of antimicrobial phosphatidylethanolamine-binding protein BmPEBP in the silkworm Bombyx mori

Phosphatidylethanolamine-binding proteins (PEBPs) are a class of highly conserved, biologically diverse proteins, which are widely distributed in plants, insects, and mammals. In this study, a Bombyx mori PEBP (BmPEBP) gene was reported, which encodes a protein composed of 209 amino acid residues. BmPEBP includes a predicted signal peptide, indicating that it is an extracellular protein, which differs from the cytoplasmic PEBPs of plants and mammals. Recombinant soluble BmPEBP was successfully synthesized using a prokaryotic expression system and was then purified effectively by Ni²⁺-NTA affinity chromatography and gel filtration. Far-ultraviolet circular dichroism spectra indicated that BmPEBP had a well-defined β-sheet structure, with the β-sheet content accounting for about 41% of the protein. BmPEBP had a relatively stable structure at temperatures ranging from 15 °C to 57.5 °C. The Tm, ΔH, and ΔS of BmPEBP were 62.27 °C ± 0.14 °C, 570.10 ± 0.17 kJ/mol, and 1.70 ± 0.03 KJ/(mol·K), respectively. Homology modeling analysis suggested that the active sites of BmPEBP were conserved, comprising Pro96, His111, and His143. Quantitative real-time PCR showed that BmPEBP was highly expressed in the silk gland and had very low expression in other tissues. However, BmPEBP expression was significantly upregulated in the larval fat body after infection with two kinds of fungi, Beauveria bassiana and Candida albicans. Moreover, in vitro fungal inhibition tests showed that BmPEBP could significantly inhibit the sporular growth of Saccharomyces cerevisiae, C. albicans, B. bassiana, and Aspergillus fumigatus. To our knowledge, this is the first report to reveal the antifungal role of a PEBP in insects.

Toll-like receptors and inflammation in metabolic neuropathy; a role in early versus late disease?

Neuropathy is a common, morbid complication of the metabolic syndrome, prediabetes, and diabetes. Recent studies have indicated a potential role for the immune system in the development of neuropathy. In particular, toll-like receptors (TLR) 2 and 4 have been linked to metabolic dysfunction, and blocking TLR4 is proposed as a treatment for neuropathic pain. In the current study, we investigated the role of the immune system, particularly TLRs 2 and 4, in the pathogenesis and progression of neuropathy. Sural or sciatic nerve gene expression arrays from humans and murine neuropathy models of prediabetes and diabetes were first analyzed to identify differentially expressed TLR2- and TLR4-associated genes within the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. We observed that genes associated with TLRs 2 and 4, particularly lipopolysaccharide binding protein (LPB) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta (PIK3CB), were dysregulated across species and across multiple murine models of prediabetic and diabetic neuropathy. To further understand the role of these pathways in vivo, TLR 2 and 4 global knockout mice placed on a 60% high fat diet (HFD-TLR2/4^-/-) were compared with wild type (WT) mice on a high fat diet (HFD-WT) and WT controls on a standard diet (CON). Mice then underwent metabolic, neuropathic, and immunological phenotyping at two time points to assess the impact of TLR signaling on neuropathy and immunity during metabolic dysfunction over time. We found that HFD-TLR2/4^-/- and HFD-WT mice weighed more than CON mice but did not have increased fasting blood glucose levels. Despite normal blood glucose levels, HFD-TLR2/4^-/- mice eventually developed neuropathy at the later time point (28 wks of age) but were somewhat protected from neuropathy at the early time point (16 wks of age) as measured by shorter hind paw withdraw latencies. This is in contrast to HFD-WT mice which developed neuropathy within 11 wks of being placed on a high fat diet and were neuropathic by all measures at both the early and late time points. Finally, we immunophenotyped all three mouse groups at the later time point and found differences in the number of peripheral blood Ly6C-myeloid cells as well as F4/80+ expression. These results indicate that TLR signaling influences early development of neuropathy in sensory neurons, potentially via immune modulation and recruitment.

Knockdown of Tripartite Motif Containing 28 suppresses the migration, invasion and epithelial-mesenchymal transition in ovarian carcinoma cells through down-regulation of Wnt/β-catenin signaling pathway

Tripartite motif containing 28 (TRIM28) is a transcriptional corepressor of Kruppel-associated box zinc finger protein, which has been reported to participate in carcinogenesis. Nonetheless, whether TRIM28 plays a role in the metastasis of ovarian carcinoma (OC) is unclear and requires further investigation. In this study, two OC cell lines (A2780 and OVCAR-3) with stable low expression of TRIM28 were established via RNA interference. We found that the migratory and invasive ability of TRIM28-silenced OC cells significantly decreased. The expression and activity of matrix metallopeptidase (MMP)-2 and MMP-9 in these OC cells were inhibited. The TRIM28 shRNA also suppressed the epithelial-mesenchymal transition (EMT) of OC cells as evidenced by the up-regulated E-cadherin and the downregulated Vimentin and N-cadherin. Additionally, the Wnt/β-catenin signaling pathway was suppressed in TRIM28-silenced OC cells: the activity of β-catenin was inhibited, the expression of total and nuclear β-catenin, Axin 2, T-cell factor 1 (TCF1) and lymphoid enhancer binding factor 1 (LEF1) were decreased, whereas the phosphorylation of β-catenin at Ser33/37 was enhanced. Further, re-expression of active β-catenin in TRIM28-silenced OC cells partly restored their metastasis in vitro. Taken together, our study demonstrates a contributory role of TRIM28 in OC metastasis in vitro, suggesting TRIM28 as a novel therapeutic target for this malignant tumor.

Abnormal RNA stability in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share key features, including accumulation of the RNA-binding protein TDP-43. TDP-43 regulates RNA homeostasis, but it remains unclear whether RNA stability is affected in these disorders. We use Bru-seq and BruChase-seq to assess genome-wide RNA stability in ALS patient-derived cells, demonstrating profound destabilization of ribosomal and mitochondrial transcripts. This pattern is recapitulated by TDP-43 overexpression, suggesting a primary role for TDP-43 in RNA destabilization, and in postmortem samples from ALS and FTD patients. Proteomics and functional studies illustrate corresponding reductions in mitochondrial components and compensatory increases in protein synthesis. Collectively, these observations suggest that TDP-43 deposition leads to targeted RNA instability in ALS and FTD, and may ultimately cause cell death by disrupting energy production and protein synthesis pathways.

Improved strength of silk fibers in Bombyx mori trimolters induced by an anti-juvenile hormone compound

BACKGROUND

Bombyx mori silk fibers with thin diameters have advantages of lightness and crease-resistance. Many studies have used anti-juvenile hormones to induce trimolters in order to generate thin silk; however, there has been comparatively little analysis of the morphology, structure and mechanical properties of trimolter silk.

METHODS

This study induced two kinds of trimolters by appling topically anti-juvenile hormones and obtained thin diameter silk. Scanning electron microscope (SEM), FTIR analysis, tensile mechanical testing, chitin staining were used to reveal that the morphology, conformation and mechanical property of the trimolter silk.

RESULTS

Cocoon of trimolters were highly densely packed by thinner fibers and thus had small apertures. We found that the conformation of trimolter silk fibroin changed and formed more β-sheet structures. In addition, analysis of mechanical parameters yielded a higher Young's modulus and strength in trimolter silk than in the control. By chitin staining of silk gland, we postulated that the mechanical properties of trimolters' silk was enhanced greatly during to the structural changes of silk gland.

CONCLUSION

We induced trimolters by anti-juvenile hormones and the resulting cocoons were more closely packed and had smaller silk fiber diameters. We found that the conformation of trimolters silk fibroin had a higher content of β-sheet structures and better mechanical properties.

GENERAL SIGNIFICANCE

Our study revealed the structures and mechanical properties of trimolter silk, and provided a valuable reference to improve silk quality by influencing molting in silkworms.

Endotoxin Removal from Albumin and Saline Solutions

Microporous membranes have been developed which can remove endotoxins selectively from electrolyte and albumin solutions by regioselective adsorption in the membrane matrix and outside surface of the membrane. The membranes were prepared in the form of hollow fibre membranes in a continuous process. By varying the membrane preparation parameters, different pore sizes and adsorption capacities could be realized, thus broadening applications for biological purification. Dynamic adsorption capacities for endotoxin from albumin and saline solution were determined and were found to be in the range of 0.2 and 0.1 μg endotoxin/g membrane, respectively, suggesting different adsorption mechanisms. (Int J Artif Organs 2007; 30: 589–93)

[Analysis of contrast echocardiography for detecting right to left shunt in adults with patent foramen ovale]

Objective: To analyze the contrast echocardiography for detecting right to left shunt in adults with patent foramen ovale(PFO), and study the relationship between PFO and cryptogenic stroke. Methods: Clinical data of forty-six adults patients with PFO diagnosed by transesophageal echocardiography(TEE)from March, 2012 to March, 2017 were retrospectively collected, and the patients were divided to 3 groups according to the direction and brightness of the color Doppler shunts: obvious left-to-right shunt (OLRS, group A), weak left-to-right shunt(WLRS, group B), bi-directional shunt(BDS, group C). A right-to-left shunt (RLS) scale was calculated using the method of 10 ml hand-operated saline for contrast echocardiography. Results: There were seventeen cases in group A, four cases (23.5%) showed RLS at level 1, and thirteen cases (76.5%) showed no RLS; there were twenty cases in group B, and all cases (100%) showed RLS, with five cases (25%) at level 1 and fifteen cases (75%) at level 2-3; there were nine cases in group C, and all cases (100%) showed RLS, with two cases (22.2%) at level 1 and seven cases (77.8%) at level 2-3. Anteroposterior diameter of left atrium of patients with no RLS (4.8 cm±0.6 cm) was significantly larger than that of patients with RLS in contrast echocardiography (3.6 cm±0.5 cm)(P=0.000). Conclusions: OLRS of adults with patent foramen ovale and with larger left atrium have less RLS than WLRS and DLRS with normal left atrium in contrast echocardiography.The possibility of paradoxical embolism in WLRS and DLRS is higher than that in OLRS, which should be taken seriously in clinical practice.

Proteomics Provides Insight into the Interaction between Mulberry and Silkworm

Mulberry leaves have been selected as a food source for the silkworm (Bombyx mori) for over 5000 years. However, the interaction mechanisms of mulberry-silkworm remain largely unknown. We explore the interaction between mulberry and silkworm at the protein level. Total proteins were extracted from mulberry leaves and silkworm feces on day 5 of the fifth larval instar and analyzed on shotgun liquid chromatography-tandem mass spectrometry, respectively. In total, 2076 and 210 foliar proteins were identified from mulberry leaves and silkworm feces, respectively. These proteins were classified into four categories according to their subcellular location: chloroplast proteins, mitochondrial proteins, secretory-pathway proteins, and proteins of other locations. Chloroplast proteins accounted for 68.3% in mulberry leaves but only 23.2% in the feces. In contrast, secretory-pathway proteins had low abundance in mulberry leaves (7.3%) but were greatly enriched to the largest component in the feces (60.1%). Most of the foliar secretory-pathway proteins in the feces were found to be resistant to silkworm feeding by becoming involved in primary metabolite, proteinase inhibition, cell-wall remodeling, redox regulation, and pathogen-resistant processes. On the contrary, only six defensive proteins were identified in the fecal chloroplast proteins including two key proteins responsible for synthesizing jasmonic acid, although chloroplast proteins were the second largest component in the feces. Collectively, the comparative proteomics analyses indicate that mulberry leaves not only provide amino acids to the silkworm but also display defense against silkworm feeding, although the silkworm grows very well by feeding on mulberry leaves, which provides new insights into the interactions between host-plant and insect herbivores.

Effect of selective serotonin reuptake inhibitors on expression of 5-HT1AR and neurotransmitters in rats with vascular dementia

5-hydroxytryptamine receptor 1A (5-HT1AR) is closely associated with cognitive functions. Selective serotonin reuptake inhibitors (SSRIs) can protect individuals from brain damage following ischemia/hypoxia. To investigate the function of SSRIs in vascular dementia (VD), we established a rat model of VD, and observed the effect of SSRIs on the expression of 5-HT1AR mRNA and neurotransmitters. Male SD rats (6 months) were randomly assigned into sham, model, and SSRI groups (N = 30). VD was achieved by permanent ligation of the bilateral common carotid artery. Escitalopram, a highly selective 5-HT reabsorption inhibitor, was ip injected into the rats for three consecutive weeks. The Morris water-maze was used to test learning and memory. H&E staining for neuronal injury was conducted on cortical and hippocampal tissues. HPLC was used to determine the levels of dopamine (DA), 5-HT, and norepinephrine (NE). RT-PCR was used to determine expression of 5-HT1AR mRNA. As compared to control rats, model animals demonstrated elongated escape latency, lower platform crossing times, and significant injuries to hippocampal CA1 neurons. This was accompanied by reductions in DA, 5-HT, and NE levels in hippocampal tissues, as well as reduced cortical 5-HT and decreased 5-HT1AR mRNA expression (P < 0.05). Escitalopram treatments reduced escape latency, elevated platform crossing times, improved CA1 neuronal damage, increased DA and 5-HT levels in hippocampal and cortical neurons, as well as elevated expression of 5-HT1AR mRNA (P < 0.05). Therefore, SSRIs may improve cognitive dysfunction of VD rats, possibly by stimulating expression of neurotransmitters and protecting neurons.

Methicillin-Resistant Staphylococcus Aureus infection exacerbates NSCLC cell metastasis by up-regulating TLR4/MyD88 pathway

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major public health problem worldwide, which brings to a more great threat for cancer patients. It's necessary to give attentions to lung cancer combined with MRSA. This study mainly focuses on the influences of MRSA on lung cancer cells (A549). We first found that MRSA infection can enhance metastasis ability of A549 cell and increase matrix metalloproteinase (MMP2 and MMP9) expressions in MRSA-infected A549 cell. Toll-like receptors (TLRs) have been reported to play an important role in tumor cell initiation and migration, and regulate the expression of MMPs in tumors. Our further research indicates that Toll-like receptor 4 (TLR4)/molecules myeloid differentiation factor 88 (MyD88) signaling was up-regulated in MRSA-infected A549 cell. After silencing TLR4 or MyD88 gene, the enhanced metastasis ability of A549 cell by MRSA was decreased significantly; Also, MMP2 and MMP9 expression increase was reversed. In conclusion, MRSA infection can enhance NSCLC cell metastasis by up-regulating TLR4/MyD88 signaling.

Serine protease P-IIc is responsible for the digestion of yolk proteins at the late stage of silkworm embryogenesis

In silkworms, yolk proteins comprise vitellin, egg-specific protein and 30K proteins, which are sequentially degraded by endogenous proteases strictly regulated during embryogenesis. Although the process has been extensively investigated, there is still a gap in the knowledge about the degradation of silkworm yolk proteins on the last two days of embryonic development. In the present study, we isolated and purified a gut serine protease P-IIc, which demonstrated optimal activity at 25 °C and pH 11. Semi-quantitative RT-PCR combined with western blotting showed that P-IIc was actively expressed and significantly accumulated in the gut on the last two days of embryogenesis. When natural yolk proteins were incubated with P-IIc in vitro, vitellin and ESP were selectively degraded. P-IIc also demonstrated activity towards 30K proteins as evidenced by rapid and complete digestion of BmLP1 and partial digestion of BmLP2 and BmLP3. Furthermore, RNAi knockdown of P-IIc in silkworm embryos significantly reduced the degradation rate of residual yolk proteins on embryonic day 10. Taken together, our results indicate that P-IIc represents an embryonic gut protease with a relatively broad substrate specificity, which plays an important role in the degradation of yolk proteins at the late stage of silkworm embryogenesis.

Flavonoids intake and risk of prostate cancer: a meta-analysis of observational studies

The aim of the study was to assess the association between total flavonoids/flavonoid subclasses intake and prostate cancer risk. Several databases were searched to select eligible studies with predefined criteria. Risk ratios (RRs) with 95% confidence intervals (CIs) were used as the effect size. Publication bias and sensitivity analysis were performed. A total of five studies including four prospective cohort studies and one case-control study were included in the meta-analysis. The pooled result demonstrated a significantly increased risk of prostate cancer with higher intake of total flavonoids (RR = 1.12, 95% CI: 1.02-1.23, P = 0.013). However, sensitivity analysis indicated that there lacked a significant association after removing the study of Wang et al. (RR = 1.17, 95% CI: 0.94-1.46). Subgroup analysis stratified by flavonoids subclasses found that higher intake of anthocyanidins and flavan-3-ols were significantly associated with increased prostate cancer risk (RR = 1.12, 95% CI: 1.03-1.21, P = 0.011; RR = 1.21, 95% CI: 1.10-1.32, P < 0.001). Sensitivity analysis also indicated that after removing Wang's study, no significant association between anthocyanidins intake and prostate cancer risk was detected (RR = 1.22, 95% CI: 0.97-1.54). In conclusion, higher intake of flavonoids may not be associated with prostate cancer risk.