[Effects of reduced portosystemic flow on hepatic myelopathy in patients with cirrhosis after TIPS].

Objective: To investigate the impact of a reduced portacaval shunt on hepatic myelopathy (HM) in patients with cirrhosis after a transjugular intrahepatic portosystemic shunt (TIPS). Methods: Patients who developed HM after receiving TIPS at the First Affiliated Hospital of Xi'an Jiaotong University from January 2013 to June 2018 were retrospectively analyzed. HM severity was quantified by clinical spasticity index (CSI) and Fugl-Meyer Assessment (FMA) of the lower extremity. Clinical manifestations were combined with grades Ⅰ-Ⅳ. HM patients were divided into drug treatment (group A) and flow restriction group (group B) according to different treatment methods. The changes in CSI and FMA of the lower extremity after treatment were statistically analyzed in the two groups. P<0.05 was considered a statistically significant difference. Results: A total of 421 cases of cirrhosis who underwent TIPS were enrolled. Among them, 30 developed HM, with 22 in group A and 8 in group B. The incidence of HM after TIPS surgery was about 7.13%. After treatment, CSI was gradually increased and FMA of lower extremity was gradually decreased in group A, while vice-versa in group B. CSI in the two groups were differed significantly at 6, 12, 18, and 24 months after treatment (P<0.05), while the difference in FMA of the lower extremity was statistically significant at 12, 18, and 24 months after treatment (P<0.05). CSI was decreased and FMA of lower extremity was increased after treatment in patients with group A HM grade I. CSI, and FMA of lower extremity changes were statistically significant (P<0.05) when compared with patients with HM grades Ⅱ-Ⅳ. The incidence of hepatic encephalopathy was significantly lower in group B than that in group A (P=0.034), but there was no statistically significant difference between the two groups in the incidence of gastrointestinal bleeding, ascites, infection, MELD score and mortality. Conclusion: A reduced portacaval shunt can improve HM in patients with liver cirrhosis after TIPS, and drug therapy alone is effective for patients with early HM grade I.

[Association between occupational noise exposure and the risk of cardiovascular diseases].

Objective: To explore the association between occupational noise exposure and cardiovascular disease (CVD) risk in a large Chinese population. Methods: In December 2019, the study included 21412 retired participants from the Dongfeng-Tongji Cohort Study at baseline from September 2008 to June 2010, occupational noise exposure was evaluated through workplace noise level and/or the job titles. In a subsample of 8931 subjects, bilateral hearing loss was defined as a pure-tone mean of 25 dB or higher at 0.5, 1 , 2, and 4 kHz in both ears. Logistic regression models were used to explore the association of occupational noise exposure, bilateral hearing loss with 10-year CVD risk. Results: Compared with participants without occupational noise exposure, the 10-year CVD risk was significantly higher for noise exposure duration ≥20 years (OR=1.20, 95%CI:1.01-1.41 , P=0.001) after adjusting for potential confounders. In the sex-specific analysis, the association was only statistically significant in males (OR=2.34, 95%CI: 1.18-4.66, P<0.001) , but not in females (OR=1.15, 95%CI:0.97-1.37, P=0.153). In the subsample analyses, bilateral hearing loss, which was an indicator for exposure to loud noise, was also associated with a higher risk of 10-year CVD (OR= 1.17, 95% CI:1.05-1.44, P <0.001) , especially for participants who were males (OR =1.24, 95% CI:1.07-2.30, P<0.001) , aged equal and over 60 years old (OR=2.30, 95%CI: 1.84-2.88, P<0.001) , and exposed to occupational noise (OR=1.66, 95%CI: 1.02-2.70, P=0.001). Conclusion: Occupational noise exposure may be a risk factor for CVD.

[Advances in the study of occult malignant tumor-related pyogenic liver abscesses in the digestive system].

Pyogenic liver abscess (PLA) accompanied by occult malignant tumors is a rare kind of life-threatening disease. Studies have shown that it can predict the occurrence of cancer, especially hepatobiliary and colorectal cancer. The risk of combined occult primary liver cancer, cholangiocarcinoma, and gastrointestinal cancer is high in PLA patients. Malignant tumor-related PLA lacks specific symptoms and signs. The iodine concentration ratio between the energy spectrum CT lesions and normal liver tissue is of certain value in the differentiation of liver cancer and liver abscess. Computed tomography colonography has a dual role. It can screen patients with PLA for occult colorectal cancer and determine the treatment response of abscess lesions. Klebsiella pneumoniae and Escherichia coli is the main microorganism of PLA related to colorectal cancer, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma. PLA treatment related to hepatobiliary malignant tumor has high complications and mortality, and poor prognosis. Most occult colorectal cancers are in the early stage, and their early detection and prognosis are better than those of PLA patients combined with hepatobiliary malignancies.

Tumor suppressor RKIP inhibits prostate cancer cell metastasis and sensitizes prostate cancer cells to docetaxel treatment.

Raf kinase inhibitory protein (RKIP) is a well-established metastasis suppressor that is frequently down-regulated in aggressive cancers. However, the impact of RKIP on cancer cell invasion and metastasis in prostate cancer is still elusive. To this end, we overexpressed RKIP in two prostate cancer cell lines. We found that overexpression of RKIP inhibited prostate cancer cells proliferation, migration and invasion. Mechanistically, we found that RKIP overexpression led to down-regula- tion of the NF-kB signaling pathway and inhibition of the epithelial-to-mesenchymal transition, which is important step for cancer metastasis. In addition, overexpression of RKIP can promote drug effects of docetaxel on prostate cancer cell lines. In conclusion, overexpression of RKIP significantly inhibits prostate cancer cell migration and metastasis, and overexpression of RKIP could aid prostate cancer treatment and therapy.

[The effects of Xuebijing injection on apoptosis and expression of regulatory factors TNF-α、NF-κB and Caspase-3 expression in the lung tissues of acute paraquat-induced rats].

Objective: To explore the mechanism of Xuebijing injection in the treatment of acute paraquat poisoning by means of studying the expression of TNF-alpha, NF-kappa B, Caspase-3 and the changes of cell apoptosis rate detected by TUNEL in the lung tissue of acute paraquat-induced rats. Methods: On the base of random number table, 126 Wister rats weighing 220 g to 270 g were divided into 3 groups: (1) Control group: 42 rats, (2) Poisoned group: 42 rats, (3) Treatment group: 42 rats. On 1(st)、3(rd)、7(th)、14(th)、21(st)、28(th)、and 35(th) day, six rats from each group were anaesthetized by intraperitoneal injection of chloral hydrate. To cut the chest and take the lung tissue samples. The expression levels of Tumor Necrosis Factor-alpha, Nuclear Factor-kappa B and Caspase-3 protein in lung tissue were detected by immunohistochemical staining, as well as apoptotic cell rate was detected by TUNEL staining. Results: The expression levels of Tumor Necrosis Factor-alpha, Nuclear Factor-kappa B, Caspase-3 protein and TUNEL staining in the lung tissue of the poisoned group was significantly higher than that of the control group (P<0.05) . Compared with the poisoned group, the expression of TNF-alpha, NF-kappa B, Caspase-3 and TUNEL in treatment group decreased significantly (P<0.05) , but they were still higher than those of the control group, and the difference was statistically significant compared with the control group (P<0.05) . Conclusion: Apoptosis and TNF-alpha, NF-kappa B and Caspase-3 play an important role in lung injury of paraquat-induced rats. Xuebijing injection can inhibit the expression of TNF-alpha, NF-kappa B, Caspase-3 in lung tissue, reduce the apoptosis rate and alleviate the damage of lung tissue in paraquat-poisoning rats.

Association of interleukin-6 gene polymorphisms and circulating levels with keloid scars in a Chinese Han population.

The aim of the present study is to explore the effect of IL-6 gene polymorphisms on the development of keloid scar (KS) in the Chinese Han population. Genotyping of IL-6 was performed by the polymerase chain reaction (PCR), followed by restriction fragment length polymorphism assays (PCR-RFLP). Serum level of IL-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results indicated that when the IL-6 -572 CC homozygote genotype was used as the reference group, the GG genotype was found to be associated with a significantly increased risk of KS (GG vs CC: OR = 2.097, 95%CI  = 1.100-3.995, P  =  0.025). When the IL-6 -572 C allele was used as the reference group, the G allele was found to be associated with significantly increased risk of KS (G vs C: OR =  1.317, 95%CI  = 1.002-1.730, P = 0.048). Furthermore, we observed a marked increase in serum IL-6 levels in KS patients with GG genotypes when compared to KS patients harboring the CC genotype. In conclusion, our results suggest that IL-6 gene polymorphism was associated with keloid scars in the southeastern Chinese Han population.

Extraction of proteins and preliminary characterization of physicochemical properties in Toona sinensis fruit.

We investigated the extraction of Toona sinensis fruit proteins and preliminarily characterized their physicochemical properties. The results showed that optimal extraction occurred under conditions of pH 10.5, a duration of 40 min, a liquid-to-solid ratio of 25:1, and a temperature of 40°C by an orthogonal design using T. sinensis fruit protein as the index and single factor. The total nitrogen content was 13.8 g/100 g and included 17 different amino acids. The glutamate level was highest at 35.37%, followed by arginine at 15.31%. The isoelectric point of T. sinensis fruit protein was between 6.8 and 10.0 with a typical absorption peak by infrared chromatography. Three protein bands were analyzed using SDS-polyacrylamide gel electrophoresis, with relative molecular weights of 55, 51, and 22 kDa. This study provides a theoretical basis for the comprehensive utilization of T. sinensis fruit by further investigating the biological activity of its proteins.

Hypoxia facilitates epithelial-mesenchymal transition-mediated rectal cancer progress.

Rectal cancer is a commonly observed tumor in clinics, and epithelial-mesenchymal transition (EMT) is very important for tumor invasion and metastasis. We established a rectal cancer HCT-116 cell hypoxia model and detected cell proliferation, invasion, and EMT-related protein expression in this model, aiming to analyze the effect of hypoxia on rectal cancer cell EMT. Rectal cancer cell line HCT-116 was cultured in normoxic, hypoxic, or anaerobic environment, and hypoxia-inducible factor-1α (HIF-1α) mRNA expression was detected in the cells by real-time PCR. Cell proliferation was tested by MTT assay; cell invasion was determined by transwell assay, and HIF-1α, epithelial-cadherin, and Snail protein levels were evaluated by western blot analysis. HIF-1α mRNA level significantly increased in the anaerobic group compared to that in the normoxic and hypoxic groups (P < 0.05). HCT-116 cell proliferation in the anaerobic group was obviously higher than that in the other two groups, with the hypoxic group showing stronger proliferative ability than the normoxic group (P < 0.05). Compared to the normoxic group, the HCT-116 cells demonstrated enhanced cell invasion and migration in hypoxic and anaerobic groups. HIF-1α and Snail expressions were upregulated, whereas epithelial-cadherin expression had declined in the hypoxic and anaerobic groups, compared to those in the normal control (P < 0.05). Therefore, hypoxia promoted rectal cancer cell progress by increasing HIF-1α to induce EMT.

Association of the interleukin-10 gene -1082A/G genetic polymorphism with risk of ischemic stroke in a Chinese population.

We investigated the possible association between two single nucleotide polymorphisms of IL10 (-1082A/G and -592C/A) and susceptibility to ischemic stroke. In total, 335 patients with proven ischemic stroke and 335 control subjects were recruited from Xinxiang Central Hospital between March 2013 and May 2015. The IL10 -1082A/G and -529C/A polymorphisms were investigated by polymerase chain reaction-restriction fragment length polymorphism. When compared with the control subjects, patients with ischemic stroke were more likely to be male, have a habit of tobacco smoking, have higher BMI, have hypertension or diabetes mellitus, and have higher levels of TC, LDL-C, HDL-C, and TG. The multivariate logistic regression analyses revealed that the AA genotype of IL10 -1082A/G was significantly associated with development of ischemic stroke in a Chinese population compared with the GG genotype (OR = 1.93, 95%CI = 1.15-3.25). In the dominant model, the association between GA+AA genotype of IL10 -1082A/G and risk of ischemic stroke was also significant compared with the GG genotype, and the adjusted OR (95%CI) for the GA+AA genotype was 1.41 (1.02-1.94). Thus, our study suggests that IL10 gene polymorphisms contribute to the development of ischemic stroke.

Association between a microRNA-214 binding site polymorphism in the methylenetetrahydrofolate reductase gene and esophageal squamous cell carcinoma.

MicroRNAs (miRNAs) are key regulators of gene expression and play an important role in the development and progression of various diseases including esophageal squamous cell carcinoma (ESCC). In this study, we determined whether a polymorphism at the miR-214 binding site in the 3'-untranslated region (3'-UTR) of the methylenetetrahydrofolate reductase gene (MTHFR) is associated with susceptibility to ESCC. A total of 448 ESCC cases and 460 gender- and age-matched subjects were recruited for the study. The genotypes of the rs114673809 single nucleotide polymorphism (SNP) were determined by polymerase chain reaction sequencing. Associations between genotypes of MTHFR rs114673809 and ESCC risk were determined using logistic regression analyses. In the recessive model, when the MTHFR rs114673809 GG homozygote genotype was used as the reference group, the GA genotype was not associated with the risk of ESCC (GA vs GG: OR = 1.261, 95%CI = 0.960-1.657, P = 0.110), but the AA genotype was associated with increased risk of ECSS (AA vs GG: OR = 1.752, 95%CI = 1.076-2.853, P = 0.027). Additionally, the rs114673809 A allele carriers also showed a 1.286-fold increased ESCC risk compared with those carrying the rs114673809 G allele genotype. Furthermore, we observed a significant increase in plasma homocysteine levels in ESCC cases carrying the AA genotype relative to ESCC cases carrying the GG genotype. Our data demonstrate that a polymorphism at the miR-214 binding site in the 3'-UTR of MTHFR is an ESCC susceptibility SNP in the Chinese population.

Protective effect of the n-butanol Toona sinensis seed extract on diabetic nephropathy rat kidneys.

The objective of this study was to observe the protective effect of the n-butyl alcohol phase of Toona sinensis seed extract on the kidneys of diabetic nephropathy (DN) rats and its preliminary mechanism. Male wistar rats were administered a normal or high-fat diet for 1 month. DN rats were divided into a model group and a petroleum ether phase of T. sinensis seed extract intervention group. The intervention group was administered 5 mg·100 g-1·day-1 extract. After treatment for 10 weeks, the rats were sacrificed and blood samples and the renal cortex were collected. Biochemical indicators in the serum and renal indices were assessed. Pathological changes of the renal tissues were also determined. Changes in the renal structure and protein levels were detected. Compared with the normal group, the blood glucose, urinary albumin, renal index, and oxidative stress index were sharply increased in the model group. The protein levels of TGF-b1, collagen IV, and connective tissue growth factor (CTGF) were increased. Compared with the model group, the n-butyl alcohol phase of T. sinensis seed extract significantly reduced the blood glucose, urinary albumin, renal index, oxidative stress index, serum creatinine, and urea nitrogen levels. The renal pathology abnormality was improved in DN rats. The protein levels of TGF-b1, collagen IV, and CTGF were increased. The expression of TGF-b1, collagen IV, and CTGF decreased. In conclusion, the n-butyl alcohol phase of T. sinensis seed extract has protective effects on DN rats via the inhibition of oxidative stress and protein expression of TGF-b1, collagen IV, and CTGF.

NtBRC1 suppresses axillary branching in tobacco after decapitation.

Axillary branching is controlled by a very complex mechanism involving various endogenous and environmental factors. Previous studies have shown that Tb1/BRC1 is the point of integration in the network of molecular mechanisms regulating axillary branching in plants. In this study, we cloned the Tb1/BRC1 ortholog, NtBRC1, from Nicotiana tabacum and functionally analyzed its role in the control of axillary branching in tobacco. Overexpression of NtBRC1 resulted in significant retardation of axillary branching, and downregulation of this gene resulted in significant acceleration of axillary branching after decapitation. This indicates a negative role for this gene in the regulation of axillary branching. In-line with previous reports, NtBRC1 was found to be expressed predominantly in axillary buds. Additionally, as expected, expression was decreased 8 h following decapitation, which further confirms its role in the suppression of axillary branching. Furthermore, the expression of NtBRC1 was significantly downregulated by cytokinin, but was not affected by GR24, a synthetic strigolactone. Based on the data collected in the present study, we demonstrate that NtBRC1 negatively regulates axillary branching in tobacco after decapitation and functions downstream of the cytokinin signaling pathway inside axillary buds.

[Clinical application of MRI histogram in evaluation of muscle fatty infiltration].

OBJECTIVE: To describe a method based on analysis of the histogram of intensity values produced from the magnetic resonance imaging (MRI) for quantifying the degree of fatty infiltration. METHODS: The study included 25 patients with dystrophinopathy. All the subjects underwent muscle MRI test at thigh level. The histogram M values of 250 muscles adjusted for subcutaneous fat, representing the degree of fatty infiltration, were compared with the expert visual reading using the modified Mercuri scale. RESULTS: There was a significant positive correlation between the histogram M values and the scores of visual reading (r=0.854, P<0.001). The distinct pattern of muscle involvement detected in the patients with dystrophinopathy in our study of histogram M values was similar to that of visual reading and results in literature. The histogram M values had stronger correlations with the clinical data than the scores of visual reading as follows: the correlations with age (r=0.730, P<0.001) and (r=0.753, P<0.001); with strength of knee extensor (r=-0.468, P=0.024) and (r=-0.460, P=0.027) respectively. Meanwhile, the histogram M values analysis had better repeatability than visual reading with the interclass correlation coefficient was 0.998 (95% CI: 0.997-0.998, P<0.001) and 0.958 (95% CI: 0.946-0.967, P<0.001) respectively. CONCLUSION: Histogram M values analysis of MRI with the advantages of repeatability and objectivity can be used to evaluate the degree of muscle fatty infiltration.

[Magnetic resonance imaging of dystrophinopathy that mimics adductor enthesopathy].

OBJECTIVE: To report thigh muscle magnetic resonance imaging (MRI) tests of four Chinese patients with dystrophinopathy with edema changes in adductor longus muscles that mimics adductor enthesopathy. METHODS: Four boys, who were from four unrelated families and aged from 5 to 11 years, were investigated because of the clinical manifestations including myalgia or muscle weakness or the incidental findings of elevated serum creatine kinase levels, and were diagnosed with dystrophinopathy by gene test of Duchenne muscular dystrophy (DMD). Their creatine kinase levels were increased from 4 087 IU/L to 32 700 IU/L (Normal range: 75-175 IU/L). The muscle biopsy of three patients all demonstrated a dystrophic pattern including necrosis, regeneration, hypertrophy, atrophy and connective tissue proliferation, with different proportions of dystrophin-negative muscle fibers. The gene test of DMD showed an out-frame deletion of exons in three of the four patients, involving either exons 45 or exons 49-52 deletion or exon 62 duplication, and c.2665 C>T with nonsense mutation in the other one. Muscle MRI tests of the bilateral thighs were performed with T1 weighed sequence and slow tau inversion recovery sequence. The degree of fatty infiltration changes was scored. RESULTS: MRI of the thigh muscles showed mild to severe fatty infiltration changes in T1 weighed sequence with the total scores from 2 to 13.The most severe fatty infiltration changes were in the long head of biceps femoris and adductor magnus. Obvious hyperintensities appeared mainly in the adductor longus muscles on slow tau inversion recovery (STIR) images in all the patients without any abnormal signals in the attachment of the ligament, indicating edema changes of the adductor longus muscles which mimiced adductor enthesopathy. Two of the four patients presented with edema changes in the bilateral adductor longus muscles, while the other two were with only unilateral changes. Furthermore, other thigh muscles, including adductor magnus, semitendinosus, sartorius and rectus femoris muscles, could also have mild edema changes in two of the four patients. CONCLUSION: Dystrophinopathy can manifest as edema changes in the adductor longus muscles in thigh muscle MRI tests, which is a typical lesion in adductor enthesopathy. The adductor longus muscles in the dystrophinopathy patients may be easy to be impaired due to traction injury during sports.

Tobacco serine/threonine protein kinase gene NrSTK enhances black shank resistance.

A serine/threonine protein kinase gene (NrSTK) was cloned from Nicotiana repanda based on the sequence of a previously isolated resistance gene analog (RGA). Expression of RGA was induced by challenge with the pathogen black shank. The NrSTK gene was predicted to encode a protein kinase that contained an ATP binding site at residues 41-69 and a serine/threonine protein kinase activation sequence spanning the region 161-173. Overexpression of NrSTK in the susceptible tobacco variety Honghuadajinyuan significantly enhanced resistance to black shank, indicating that NrSTK plays a role in incompatibility reactions between tobacco and the pathogen. Characterization of NrSTK will help elucidate the molecular mechanisms involved in black shank resistance in N. repanda.

Cloning, sequence characterization, and expression patterns of members of the porcine TSSK family.

Testis-specific serine kinases (TSSKs) are a family of serine/threonine kinases highly expressed in the testes that are responsible for regulating many spermatogenesis-related protein activities. Mutations in this family have a positive relationship with oligospermia and azoospermia in human and mouse. Here, five members of the TSSK family from a Banna mini-pig inbred line (BMI) were cloned, sequenced, and characterized. The full-length coding sequences of BMI TSSKs varied from 807 (TSSK3) to 1095 bp (TSSK1) and encoded 268 to 364 amino acids with molecular weights in the range 30.11 to 41.34 kDa. Following comparison with TSSK4 genes in other species, BMI TSSK4 was found to contain three alternatively spliced variants, inform1, inform 3, and inform 4. BMI TSSK1 and TSSK2 are co-localized on the Sus scrofa chromosome (SSC) 14, and consist of a single exon; TSSK3, TSSK4, and TSSK6 are on SSC6, SSC7, and SSC2, and consist of two, four, and one exon, respectively. Multiple protein sequence alignment and phylogenetic analysis showed that the regions spanning the S_TKc domains were more conserved between pig and other animals: with TSSK1 and TSSK2 and TSSK3 and TSSK6 displaying the greatest degree of homology across species, and the TSSK4 protein clearly distinct from other members. Multi-tissue RT-PCR showed BMI TSSK1, TSSK3, and TSSK4 were only expressed in the testes and seminal vesicle, TSSK2 was confined to testes only, while TSSK6 was expressed widely in adult tissues but was highest in the testes.

Isolation, molecular cloning, and characterization of a novel porcine lymphotoxin beta receptor gene.

The lymphotoxin beta receptor (LTßR) is a member of the tumor necrosis factor family of receptors (TNFR). It plays a role in regulating lymphoid organogenesis and homeostasis of the immune system. In the present study, the full coding region of a putative LTßR gene of Sus scrofa was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and cloned for the first time (accession Nos. JX457347 and AFU74012). In addition, analysis of the tissue expression profile was carried out via RT-PCR. The full-length coding region of porcine LTßR had 1266 nucleotides (molecular weight, 45.61 kDa; pI, 5.71) and encoded 421 amino acids. Bioinformatic prediction indicates that LTßR belongs to the TNFR superfamily and contains a TNFR domain. The sequence homology analysis revealed that the amino acid sequences of S. scrofa LTßR had 82.9, 82.4, 81.3, 80.5, 78.7, 74.6, and 73.0% identity with those of Equus caballus, Canis lupus, Ailuropoda melanoleuca, Oryctolagus cuniculus, Bos taurus, Mus musculus, and Homo sapiens, respectively. The phylogenetic tree based on the amino acid sequences of LTßR from 8 species revealed that S. scrofa was more closely related to E. caballus, C. lupus, and A. melanoleuca. RT-PCR analysis showed that the porcine LTßR gene was differentially expressed (e.g., high, moderate, low, or nonexistent) in various tissues (e.g., prostate, pituitary, brainstem, and esophagus, respectively). This may be related to differences in the regulation of LTßR in the different tissues.

Surface modification of graphene nanopores for protein translocation.

Studies of DNA translocation through graphene nanopores have revealed their potential for DNA sequencing. Here we report a study of protein translocation through chemically modified graphene nanopores. A transmission electron microscope (TEM) was used to cut nanopores with diameters between 5 and 20 nm in multilayer graphene prepared by chemical vapor deposition (CVD). After oxygen plasma treatment, the dependence of the measured ionic current on salt concentration and pH was consistent with a small surface charge induced by the formation of carboxyl groups. While translocation of gold nanoparticles (10 nm) was readily detected through such treated pores of a larger diameter, translocation of the protein ferritin was not observed either for oxygen plasma treated pores, or for pores modified with mercaptohexadecanoic acid. Ferritin translocation events were reliably observed after the pores were modified with the phospholipid-PEG (DPPE-PEG750) amphiphile. The ion current signature of translocation events was complex, suggesting that a series of interactions between the protein and pores occurs during the process.