Diagnostic value of a combined serology-based model for minimal hepatic encephalopathy in patients with compensated cirrhosis / 中华检验医学杂志

Objective:To investigate the diagnostic accuracy of serological indicators and evaluate the diagnostic value of a new established combined serological model on identifying the minimal hepatic encephalopathy (MHE) in patients with compensated cirrhosis.Methods:This prospective multicenter study enrolled 263 compensated cirrhotic patients from 23 hospitals in 15 provinces, autonomous regions and municipalities of China between October 2021 and August 2022. Clinical data and laboratory test results were collected, and the model for end-stage liver disease (MELD) score was calculated. Ammonia level was corrected to the upper limit of normal (AMM-ULN) by the baseline blood ammonia measurements/upper limit of the normal reference value. MHE was diagnosed by combined abnormal number connection test-A and abnormal digit symbol test as suggested by Guidelines on the management of hepatic encephalopathy in cirrhosis. The patients were randomly divided (7∶3) into training set ( n=185) and validation set ( n=78) based on caret package of R language. Logistic regression was used to establish a combined model of MHE diagnosis. The diagnostic performance was evaluated by the area under the curve (AUC) of receiver operating characteristic curve, Hosmer-Lemeshow test and calibration curve. The internal verification was carried out by the Bootstrap method ( n=200). AUC comparisons were achieved using the Delong test. Results:In the training set, prevalence of MHE was 37.8% (70/185). There were statistically significant differences in AMM-ULN, albumin, platelet, alkaline phosphatase, international normalized ratio, MELD score and education between non-MHE group and MHE group (all P<0.05). Multivariate Logistic regression analysis showed that AMM-ULN [odds ratio ( OR)=1.78, 95% confidence interval ( CI) 1.05-3.14, P=0.038] and MELD score ( OR=1.11, 95% CI 1.04-1.20, P=0.002) were independent risk factors for MHE, and the AUC for predicting MHE were 0.663, 0.625, respectively. Compared with the use of blood AMM-ULN and MELD score alone, the AUC of the combined model of AMM-ULN, MELD score and education exhibited better predictive performance in determining the presence of MHE was 0.755, the specificity and sensitivity was 85.2% and 55.7%, respectively. Hosmer-Lemeshow test and calibration curve showed that the model had good calibration ( P=0.733). The AUC for internal validation of the combined model for diagnosing MHE was 0.752. In the validation set, the AUC of the combined model for diagnosing MHE was 0.794, and Hosmer-Lemeshow test showed good calibration ( P=0.841). Conclusion:Use of the combined model including AMM-ULN, MELD score and education could improve the predictive efficiency of MHE among patients with compensated cirrhosis.

A prospective multicenter and real-world study on the diagnostic value of combination of number connection test-B and line tracing test in mild hepatic encephalopathy / 中华消化杂志

Objective:To investigate the diagnostic value of independent and combined subtests of the psychometric hepatic encephalopathy score (PHES) in mild hepatic encephalopathy(MHE) of patients with liver cirrhosis, so as to optimize the PHES.Methods:This was a prospective, multicenter and real-world study which was sponsored by the National Clinical Research Center of Infectious Diseases and the Portal Hypertension Consortium. Twenty-six hospitals from 13 provinces, autonomous regions and municipalities countrywide participated in this study, induding Tianjin Third Central Hospital, the Fourth People′s Hospital of Qinghai Province, the Second Affiliated Hospital of Baotou Medical College, the Third People′s Hospital of Taiyuan, the Fifth Medical Center of PLA General Hospital and so on. From October 2021 to February 2022, outpatients and hospitalized patients with liver cirrhosis and no obvious hepatic encephalopathy were consecutively enrolled. All patients received 5 PHES subjects in the same order: number connection test(NCT)-A, NCT-B, digit symbol test(DST), line tracing test(LTT) and serial dotting test(SDT), and the scores were calculated. The total score of PHES <-4 was taken as the cut-off value for diagnosing MHE. Compare the differences in each subtest between MHE group and non-MHE group. Receiver operating characteristic curve(ROC) and area under the curve(AUC) was performed to assess the diagnostic value of independent and combined subtests in MHE. Mann-Whitney U test and DeLong test were used for statistical analysis. Results:A total of 581 patients with liver cirrhosis were enrolled, 457 were diagnosed as MHE, and the incidence of MHE was 78.7%. The results of NCT-A, NCT-B, SDT, LTT, DST of MHE group were 60.00 s(47.01 s, 88.00 s), 90.45 s(69.32 s, 125.35 s), 74.00 s(57.65 s, 96.60 s), 74.72(60.00, 98.61) and 27.00(20.00, 36.00), respectively. Compared those of non-MHE group(34.00 s(29.15 s, 44.48 s), 50.00 s(40.98 s, 60.77 s), 50.00 s(41.07 s, 63.03 s), 46.23(38.55, 59.42) and 42.00(34.00, 50.75)), the differences were statistically significant( Z=12.37, 12.98, 9.83, 11.56, 10.66; all P<0.001). The AUC(95% confidence interval(95% CI)) of subtests of PHES NCT-B, NCT-A, LTT, DST and SDT alone in MHE diagnosis were 0.880(0.849 to 0.910), 0.862(0.828 to 0.896), 0.838(0.799 to 0.877), 0.812(0.772 to 0.851) and 0.788(0.743 to 0.832), respectively. The combination of 2 PHES subtests significantly increased the diagnostic efficacy. Among them the diagnostic efficacy of the combination of NCT-B and LTT was the best, the AUC(95% CI) was 0.924(0.902 to 0.947), the specificity was 91.9% and the sensitivity was 79.2%, which was better than a single PHES subtest (NCT-A, NCT-B, SDT, LTT and DST) and the combination of NCT-A and DST(AUC was 0.879, 95% CI0.847 to 0.910) which was recommended by guidelines on the management of hepatic encephalopathy in cirrhosis, the differences were statistically significant ( Z=3.78, 3.83, 5.57, 5.51, 5.38, 2.93; all P<0.01). Furthermore, compared between the combination of NCT-B and LTT and the combination of 3 subests of PHES, only the diagnostic efficacy of combination of NCT-B, LTT and SDT (AUC was 0.936, 95% CI 0.916 to 0.956) was better than that of the combination of NCT-B and LTT, the difference was statistically significant( Z=2.32, P=0.020). Conclusion:Based on the diagnostic efficacy and clinical feasibility of PHES subtests and their combinations, the combination of NCT-B and LTT is recommended for the diagnosis of MHE.

Epidemiological and clinical characteristics of 46 corona virus disease 2019 cases in Beijing City / 中华传染病杂志

Objective:To investigate and analyze the epidemiological and clinical characteristics of 46 patients with corona virus disease 2019 (COVID-19) in Beijing City.Methods:A retrospective study was conducted to analyze the data of 46 patients with COVID-19 in Beijing from 20th January 2020 to 8th February 2020 at the Fifth Medical Center of the PLA General Hospital in Beijing City. Twelve, 23 and 11 patients were assigned to the mild group, common group and severe group, respectively. The epidemiological history, clinical characteristics, laboratory tests and imaging inspections were analyzed. Statistical analysis used Fisher exact test. If P<0.05, post- hoc test was used for pairwise comparison, and the statistics were corrected by Bonferroni test. Results:Among the 46 patients included in this study, 27 were male and 19 were female. The age range was between 3-79 years old, and the age was (41.8±16.3) years old. The average incubation period was (4.85±3.00) days. A total of 26 cases (56.5%) were clustered patients, and 26 cases had a history of staying in Wuhan, 10 cases had contact with Wuhan personnel. Fever (39 cases, 84.8%), cough (27 cases, 58.7%), and fatigue (25 cases, 54.3%) were the main clinical symptoms for these patients. The decrease in white blood cell counts occurred in 12 patients, four had the decrease in T lymphocyte percentage, 17 had the decrease in CD4 + T lymphocyte counts, seven had the decrease in CD8 + T lymphocyte counts, 21 had the increase level of C reactive protein (45.7%), and interleukin-6 (IL-6) level increased in 32 cases (69.6%), erythrocyte sedimentation rate (ESR) increased in 23 cases (50.0%), serum ferritin level increased in 26 cases (56.5%), and blood lactic acid level increased in nine cases. There were statistically significant differences in the proportion of cases with decreased absolute value of CD8 + T lymphocytes and T lymphocytes counts among the mild, common and severe groups (all P<0.05). Comparing the proportion of cases in the three groups with elevated C reactive protein, IL-6, ESR, serum ferritin and blood lactic acid levels, the differences were statistically significant (all P<0.05). The proportion of cases with elevated C reactive protein levels in severe group was higher than those in mild and common groups. The proportion of cases with elevated IL-6, ESR, and serum ferritin levels in severe and common group were higher than those in mild group. The proportion of cases with elevated blood lactic acid levels in severe group was higher than those in mild group. The differences between the above groups were statistically significant (all adjusted P<0.017). Analysis of chest X-rays results showed that 34 patients (73.9%) had inflammation in the lungs. Conclusions:The epidemiological characteristics of patients with COVID-19 in Beijing City are mainly imported cases and clustered cases. The clinical manifestations are mainly fever, fatigue and cough. C reactive protein, IL-6, ESR, serum ferritin and blood lactic acid levels are higher in severe patients.

Change of serum zinc-α2-glycoprotein level before and after methimazol treatment in hyperthyroidism patients with Graves disease / 重庆医学

Objective To explore the roles and possible significance of zinc-α2-glycoprotein(ZAG) in Graves disease(GD) by detecting the change of serum ZAG level before and after methimazol(MMI) treatment in the patients with initial onset of Graves disease.Methods The enzyme linked immunosorbent assay(ELISA) was adopted to detect serum ZAG level in healthy population,patients with newly diagnosed GD and GD patients treated by 12-week MMI treatment.The serum thyroid hormones and thyroid related autoantibodies were determined by adopting the electrochemiluminescence immunoassay.The blood lipid levels were examined by enzymatic colorimetry.Furthermore the relationship between serum ZAG level with thyroid function,thyroid related autoantibodies and blood lipid in the patients with initial onset of GD was analyzed.Results The levels of ZAG,FT3,FT4,TT3,TT4,TGAb,TPO and TRAb in the patients with newly diagnosed GD were much higher than those in the age-and gender-matched normal healthy population,while the TSH level was significantly lower than that in the normal control group(P＜0.05);after 12-week MMI treatment in the patients with initial onset of GD,the levels of serum ZAG,FT3,FT4,TT3,TT4 and TRAb were markedly decreased,whereas the TSH level was significantly enhanced(P＜0.05 or P＜0.01).The correlation study showed that fasting serum ZAG level in the GD patients was positively correlated with FT3,FT4,TT3 and TT4(P＜0.05);and negatively correlated with TSH,FFA,TC and TG(P＜0.05).With fasting serum ZAG in the GD patients as the dependent variable,the multiple linear regression analysis showed that TSH,TC and TG were the independent related factors of plasma ZAG level.Conclnsion The serum ZAG level is closely correlated with the occurrence and development of GD,and might play an important role in the blood lipids metabolism of GD patients.

Effect of Fuzheng Jiedu Tongluofang on MMP-2 and MMP-9 and invasion of human hepatoma HepG2 cells / 中国免疫学杂志

Objective:To investigate the effect and mechanism of Fuzheng Jiedu Tongluofang on the expression of MMP-2,MMP-9 and invasion of human hepatoma HepG2 cell.Methods:Hepatioma HepG2 cell was treated with Fuzheng Jiedu Tongluofang.The cell viability was measured by CCK8.The invasion of HepG2 was detected by Transwell assay.The expression of MMP-2 and MMP-9 was analyzed by ELISA.Results:In the CCK8 assay,Fuzheng Jiedu Tongluofang could inhibit the proliferation of HepG2 cells at a density and time measure.In the Transwell assay,the inhibitory rate of invasion was 52.45% when treated with Fuzheng Jiedu Tongluofang at a concentration of 2.65 mg/ml. The ELISA assay indicated that the expression of MMP-2 and MMP-9 decreased significantly after treated with Fuzheng Jiedu Tongluofang(P<0.05). Conclusion:Fuzheng Jiedu Tongluofang suppressed the invasion of HepG2 with the possible mechanism of down-regulating the expression of MMP-2 and MMP-9 in HepG2.

Analysis of association between different HCV genotypes and serum interleukin-17, interleukin-6, and vitamin D in patients with HCV-related cirrhosis / 临床肝胆病杂志

ObjectiveTo investigate the association between different hepatitis C virus (HCV) genotypes and serum interleukin-17 (IL-17), interleukin-6 (IL-6), and vitamin D in patients with HCV-related cirrhosis. MethodsSeventy-six patients with HCV-related cirrhosis, who were admitted to 302 Hospital of PLA from January to December, 2012, were enrolled in the study, and they were divided into type 1b group (n=47) and type 2a group (n=29) according to the genotypes. The levels of serum IL-17, IL-6, and vitamin D were determined by enzyme-linked immunosorbent assay. Comparison between the two groups was made by t test, and Spearman correlation analysis was used to investigate the association between serum IL-17, IL-6, and vitamin D and genotypes. ResultsThe findings in improved Child-Pugh classification showed that there were significant differences in the percentage of grade A patients between type 1b group and type 2a group (χ2=4.97, P＜0.05); when compared with type 2a group, type 1b group showed significantly higher lentiviral titers of alpha-fetoprotein (AFP) and HCV RNA and levels of IL-17, IL-6, and tumor necrosis factor-α (TNFα) (t=21.56, 16.51, 1231, 10.71, and 7.23, respectively, all P＜0.05), but significantly lower levels of interferon-γ (IFNγ), 25(OH)D, and 1,25(OH)2D (t=3.98, 6.32, and 4.88, respectively; all P＜0.05); Spearman correlation analysis showed that the lentiviral titers of AFP and HCV RNA and the levels of IL-17 and IL-6 were positively correlated with genotype 1b and genotype 2a (all P＜0.05), while the levels of IFNγ, TNFα, and 25-OH-D were negatively correlated with genotype 1b and genotype 2a (all P＜0.05). ConclusionCompared with those with genotype 2a, HCV-related cirrhosis patients with genotype 1b have higher serum levels of IL-17, IL-6, AFP, and HCV RNA, but a lower level of vitamin D; the results suggested that there are correlations between serum IL-17, IL-6, 25-OH-D, AFP, and HCV RNA and genotype, but no significant correlation between 1,25(OH)2D and genotype.

Association of gene polymorphisms of rapsyn exons with myasthenia gravis / 中国免疫学杂志

Objective:To investigate the association of single nucleotide polymorphisms (SNPs) of receptor-associated protein at the synapse ( rapsyn ) with myasthenia gravis ( MG ).Methods: The genomic DNA was extracted from peripheral blood cells , sampled from 132 patients with MG and 153 control individuals.The 8 exons of rapsyn gene were amplified by PCR ,then the products of PCR sequenced directly.Each sequence was compared with wild-type rapsyn gene , and the association between mutation and clinical symptoms of MG analysed.Results:No mutation was found in the exons 1,2,4,5,6,7,and 8 of rapsyn gene both in MG patients and control group compared with the wild-type rapsyn gene.However,a new SNP,L222R[CTG>CGG(2)] or T665G,was found in exon-3.The allele and genotype frequencies of SNP L 222R met Hardy-Weinberg genetic equilibrium (P>0.05),indicating the group repre-sentativeness.The allele frequencies of G were not statistically different between patient and control groups ( P>0.05 ).There were differences in the 3 genotypes TT , TG and GG between patient ( 42.4% vs 48.5% vs 9.1%) and control ( 49.0% vs 33.3% vs 17.6%) groups ( P<0.05 ).The genotype frequencies of GG were statistically higher in control group than that in patient group , showing a recessive model of inheritance.Conclusion: The SNPs in the rapsyn gene are associated with MG in this study.L222R ( T665 G) is a new SNP found and allele G might be a protective factor for MG.

Construction of MuSK-mCherry fusion fluorescent protein and used for detection of MuSK antibodies in myasthenia gravis / 中国免疫学杂志

Objective:To construct a fusion protein of extracellular domain peptide fragment of muscle specific kinase ( MuSK) and fluorescent protein mCherry ,and used as antigen in the detection of antibodies against MuSK ( MuSKAb ) in the sera of patients with myasthenia gravis ( MG).Methods:The mCherry gene was amplified by PCR from vector pRSET-B and cloned into pGEM-T Easy Vector,and furthermore, cloned into Eukaryotic expression vector pMT /BiP/V5-His ( MuSK), which contains MuSK extracellular domain 22-452 amino acid peptide fragment gene to construct the fluorescent fusion protein gene MuSK -mCherry.The recombinant vector was subsequently transfected into drosophila S 2 cells for expression.The expressed fusion proteins were verified in confocal mi-croscope ,and used as antigen in the detection of MuSKAb in sera of MG patents in fluorescence immunoprecipitation test .Results:The fluorescent fusion protein MuSK-mCherry was successfully constructed and expressed.The MuSKAb in sera of patents with MG could be detected in fluorescence immunoprecipitation test using the constructed MuSK-mCherry fusion protein as antigen.Conclusion: It is available to use the constructed fluorescent fusion protein MuSK-mCherry as antigen in fluorescence immunoprecipitation test for the detection of MuSKAb in sera of patents with MG.

Clinicopathological analysis of HBV recurrence in post-liver transplantation patients / 中华器官移植杂志

Objective To investigate the clinicopathological characteristics of HBV recurrence after liver transplantation. Methods The retrospective analysis of the clinicopathological changes was performed on 17 patients who had HBV recurrence after liver transplantation in our medical department. Results HBV recurrence happened from 4 to 48 months. Twelve of them which were identified to be YMDD mutation switched to entecavir or added adefovir. Three of them receiving chemotherapy when liver cancer recurred switched to entecavir. Two of them with withdrawal of lamivudine were given lamivudine continuously. Liver function returned to the normal level and HBVDNA was ＜ 102 U/ml after anti-hepatitis B virus. The histological changes in the transplanted livers included hepatocellular degeneration, necrosis and apoptosis, portal infiltrations and fibrosis.With time after recurrence, it was easier to see hepatitis B virus replication in liver cells, incidence of acute rejection, increases of liver fibrosis and the formation of fibrous septa, even pseudolobule.Conclusion In native HBV infection livers, fibrosis occurs more early and develops rapidly. The number of virus is closely related to liver necrosis and inflammation. Early discovery and change to quick and effective treatment of anti-hepatitis B virus in time can improve greatly the prognosis of the patients.

Biofabrication with chitosan and its application progress / 生物工程学报

Chitosan is a polymer with good biocompatibility, unique pH-responsive solubility, convenient modification and easier film-formability. Chitosan could serve as an active mediator between biological components and microfabricated devices to prepare biological micro electro mechanical systems (BioMEMS) with high selectivity and sensitivity. Recently, there has been a growing interest in BioMEMS based on biofabrication of chitosan. We reviewed the mechanisms and processes of three biofabrication methods based on chitosan, including directed assembly, enzymatic assembly and self-assembly. Current applications and research progress in biological, medical and environmental fields are also discussed. Finally, future research directions are prospected.

Development of oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To develop an oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer using attenuated Salmonella typhimurium and evaluate its efficacy and protective effect.</p><p><b>METHODS</b>The eukaryotic expression vector including the MG(7)-Ag mimotope and a Th epitope was constructed, and then transduced into an attenuated Salmonella typhimurium to get the oral DNA vaccine. C57BL/6 J mice were orally immunized with 1 x 10(8) cfu Salmonella transfectants, with Salmonella harboring empty plasmid, with phophate buffered saline (PBS) as control. At the 6th week, serum titer of MG(7) antibody was detected by ELISA. In the 8th week, a [(3)H]-thymidine incorporation assay was performed to test the proliferation of murine spleen cells to the stimulant of MG(7)-Ag mimicry peptide. At the same time, Ehrlich ascites carcinoma cells expressing MG(7)-Ag were used in tumor challenge assay to evaluate the protective effect of the immunization.</p><p><b>RESULTS</b>The oral DNA vaccine induced MG(7) antibody in mice, while in vivo unprimed proliferation assay of the spleenocytes showed no difference among the three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while none in the control group was protected.</p><p><b>CONCLUSION</b>Oral DNA vaccine based on the MG(7)-Ag momitope is immunogenic. It is able to induce specific immunity response against tumor in mice, and the vaccine is partially protective.</p>

Effects of adiponectin siRNA on the glucose transport in 3T3-L1 adipocytes / 中国病理生理杂志

AIM:To construct the adenovirus vector with adiponectin (Acrp30) siRNA, and to observe its effect on the Acrp30 expression and glucose transport in 3T3-L1 adipocytes. METHODS: Mouse Acrp30 siRNA fragment was designed, synthesized and cloned into the adenovirus vector. 3T3-L1 cells were infected with the two recombinant adenoviruses, respectively. The mRNA expression and protein levels of Acrp30 in these cells were evaluated by RT-PCR and ELISA. Glucose transport was measured by 2-Deoxy-[3H]-D-glucose incorporation method. RESULTS: The recombinant adenoviruses were successfully constructed. They remarkably downregulated the expression of Acrp30 at both mRNA and protein levels in 3T3-L1 cells, and decreased the glucose transport in 3T3-L1 adipocytes (P

Study on the liver damage in type I allergy induced by histamine phosphate / 中国免疫学杂志

Objective:To present evidence for the pathogenetic role of allergic factor,histamine,in type I allergy for induction of liver damage.Methods:Three groups of rabbits were fed normally and injected (iv) daily with 0, 0.04 or 0.08 ?g/kg phosphohistamine, respectively, for days. The serum level of ALT and AST in each group rabbits was assayed dynamically during the treatment. After treatment for days, the tested rabbits were sacrificed for pathological examination of the liver tissues.Results:The serum level of both ALT and AST in rabbits treated with phosphohistamine increased significantly during the tested periods, compared to that of the control group. However, both ALT and AST levels showed no significant difference between 0.04 ?g/kg and 0.08 ?g/kg groups. Liver microscopic examination, pathological damage could be observed in the tested groups in a time-and dose-dependent manner under microscopic examination. No evident pathological change appeared in the control group.Conclusion:Liver damage could be induced by histamine dosage-and time-dependently. This pathological action of histamine, a type I allergic factor, presents further evidence for a direct role of type I allergy in the pathogenesis hepatic injury.

Serum level of soluble intercellular adhesion molecule-1(sICAM-1) and soluble vascular cell adhesion molecular-1(sVCAM-1) and its clinical significance in patients with viral hepatitis B / 中国免疫学杂志

Objective:To further explore the relationship between Type Ⅰ hypersensitivity reaction and the mechanism of the viral hepatitis B through the research of soluble intercellular adhesion molecular-1(sICAM-1) and soluble vascular cell adhesion molecular-1(sVCAM-1) levels in serum in patients with viral hepatitis B related to Type Ⅰ hypersensitivity reaction and the damage of liver cells, and therefore, provide new theory for the perfection of the immunological mechanism of hepatitis B, especially acute hepatitis B.Methods:Serum sICAM-1 and sVCAM-1 levels were measured in 45 patients with viral hepatitis B and 15 normal cases using double antibody sandwich ELISA method. ALT and AST levels were studied using omni automatic biochemistry analyzer and its correlation with sICAM-1 and sVCAM-1 were observed.Results:The sICAM-1 and sVCAM-1 levels of 7 acute hepatitis B were significantly higher than that of the normal cases. ②The sICAM-1 and sVCAM-1 levels of 38 chronic hepatitis B were also significantly higher than that of the normal cases. ③The sICAM-1 and sVCAM-1 levels of 13 cases moderate chronic hepatitis B were significantly higher than that of 16 cases mild chronic hepatitis B. ④The sICAM-1 and sVCAM-1 levels of 9 serious chronic hepatitis B were significantly higher than that of the group of mild chronic hepatitis B. ⑤Levels of sICAM-1 were significantly positively correlated with serum ALT and AST. ⑥sVACM-1 levels were significantly positively correlated with serum ALT and AST. In conclusion, sICAM-1 and sVCAM-1 levels in patients with acute hepatitis B were most remarkably increased, and then serious chronic hepatitis B, moderate chronic hepatitis B, light chronic hepatitis B in sequence.Conclusion:Serum sICAM-1 and sVCAM-1 levels in patients with viral hepatitis B may reflect the damage of liver. ②Examination of serum sICAM-1 and sVCAM-1 levels in patients with hepatitis B can be used to judge the patient’s condition and to diagnose. ③As an important indication of the inflammatory in Type Ⅰ hypersensitivity reaction, sICAM-1 and sVCAM-1 may interfere the appearence of hepatitis B and the procedure of immunological damage of liver cells.