[Pregnancy outcome analysis after radiofrequency ablation of monochorionic twin pregnancy in different gestational weeks and psychological intervention].

Objective: To investigate the effect of different gestational weeks and psychological intervention on pregnancy outcome in patients with monochorionic twin pregnancy. Methods: The clinical data of 68 patients with monochorionic twin pregnancy in the middle and late pregnancy who were treated with radiofrequency ablation in the First Affiliated Hospital of Zhengzhou University from March 2017 to April 2021 were retrospectively analyzed, including 54 patients with single chorionic and single amniotic sac and 14 patients with single chorionic and double amniotic sac. Patients were divided into three groups according to the gestational weeks:<20 weeks (n=36), 20-23 weeks (n=17) and ≥24 weeks (n=15); and were divided into intervention group (n=40) and control group (n=28) according to the preoperative psychological intervention. The pregnancy outcome of patients with different pregnancy reduction and the effect of psychological intervention on pregnancy outcome was analyzed. Results: The age of 68 patients was (30.2±4.6) years old, the gestational age was (22.2±3.2) weeks, and 60 cases (88.2%) were live births after fetal reduction. There were no significant difference in age [(31.8±4.7),(28.3±5.0),(30.3±4.0) years old] (P=0.098), abortion rate, preterm birth rate, live birth rate, delivery mode, gestational week of preterm birth, gestational week of delivery, and neonatal weight between the two groups at different gestational weeks (all P>0.05). The ages of the intervention group and the control group were (30.6±4.7) and (29.4±4.0) years old (P=0.352). After psychological intervention for 40 patients in the intervention group, the anxiety score after pregnancy reduction was reduced from (54.8±6.8) to (37.3±7.3) (P<0.001), while the depression score decreased from (62.7±7.2) to (33.2±2.4) (P<0.001). Compared with patients in the control group (12.5%, n=5), the proportion of postoperative discomfort in the intervention group was higher (53.6%, n=15) (P<0.001). Compared with the control group, there were no statistically significant difference in the postoperative preterm birth rate, abortion rate, live birth rate, delivery mode, gestational week of preterm birth, gestational week of delivery, and neonatal weight in the intervention group (all P>0.05). Conclusions: Radiofrequency ablation is a safe and effective minimally invasive technique. For complex monochorionic twin pregnancies, early fetal reduction (<20 weeks) and preoperative psychological intervention can provide a solid guarantee for a good postoperative pregnancy outcome.

Response of Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae) Under Long and Short Photoperiods.

C. NIPPONENSIS: Photoperiod is an important factor influencing many biological processes including population dynamics of many insect species in temperate zones. To determine the population response of Chrysoperla nipponensis under altered conditions (high temperature and short photoperiod) and to test whether the short photoperiod was suitable for artificial storage, the life table data of were collected at 25 °C under a long photoperiod, 15:9 h (L:D), and a short photoperiod, 9:15 h (L:D) and analyzed using the age-stage, two-sex life table approach. We found that developed faster under long photoperiod than under the short photoperiod. The shorter developmental time, higher fecundity, and higher proportion of females found during the long photoperiod resulted in higher intrinsic and net reproductive rates, but a shorter mean generation time and life expectancy compared to those reared during the short photoperiod. Individuals reared under the short photoperiod also had a high reproductive value. Population projection demonstrated that reared at long photoperiod would complete four generations in 150 d, while reared under short photoperiod would just be entering the second generation. Our results demonstrated that the different fitness values obtained for individuals by varying photoperiod lengths, were readily distinguishable when using the age-stage, two-sex life table.

[Fifth Chinese national consensus report on the management of Helicobacter pylori infection].

The fifth national consensus conference on the management of Helicobacter pylori (H.pylori) infection organized by Chinese Medical Association, Chinese Society of Gastroenterology, H. pylori and Peptic Ulcer Study Group was held at Hangzhou, Zhejiang Province on December 15-16, 2016.More than 80 members of the study group and experts in the field of H. pylori research and gastroenterology attended the meeting.Consensus preparatory group was established to draft the related statements.The quality of evidence and strength of recommendation were evaluated by GRADE system.The Delphi method using an anonymous electronic system was adopted to develop the consensus of relevant statements.Expert advices about the established statements were firstly consulted through the emails.After two rounds of consultation, the preliminary statements of consensus were discussed and modified in the conference item by item.A total of 21 core members voted for the final version, which contained a total of 48 statements and was divided into 6 parts, including indications for H. pylori eradication, diagnosis, treatment, H. pylori and gastric cancer, H. pylori infection in special populations, H. pylori and gastrointestinal microbiota.

[Long-term outcomes of lateral vocal fold autologous fat injection for unilateral vocal fold paralysis].

Objective: To investigate the long-term outcomes of patients with unilateral vocal fold paralysis resulting in dysphonia treated with lateral vocal fold autologous fat injection. To analyze the factors that may affect the long-term efficacy of the procedure. Methods: From July 2003 to June 2020, 163 patients (86 males and 77 females), aged 9-73 years (mean (34.50±12.94) years) with unilateral vocal fold paralysis resulting in dysphonia underwent transoral laryngoscopic injection of autologous fat into the lateral vocal folds. Subjective auditory perception assessment (GRBAS scale), objective acoustic assessment, voice handicap index (VHI) evaluation and stroboscopic laryngoscopy were compared before and after the surgery. Patients were followed up for 1 to 18 years, with median follow-up time of 6 years. SPSS 22.0 software was used for statistical analysis. Results: Of 163 patients, 17 patients (10.4%) had mild hoarseness (G1) and 146 patients (89.6%) had moderate to severe hoarseness (G2-3). Stroboscopic laryngoscopy revealed an arch-shaped vocal fold on the affected side, fixed in the paramedian position or abduction position, with obvious glottic closure fissure. Postoperatively, voice recovered to normal (G0) in 139 patients (85.3%), mild hoarseness (G1) in 18 patients (11.0%) and moderate hoarseness (G2) in 6 patients (3.7%). Of these, 131 patients (80.4%) showed significant improvement in hoarseness, 29 patients (17.8%) showed mild improvement and 3 patients (1.8%) showed no significant improvement in hoarseness. Objective acoustic parameters of Jitter, Shimmer, NHR and MPT improved significantly, as did VHI scores. Stroboscopic laryngoscopy showed medialization of the affected vocal folds, improved vocal fold closure and normal or nearly normal vocal fold mucosal waves. With a fat injection volume of 3.0-4.5 ml, the patient's subjective auditory perception scores of G, R, B and A improved more significantly within 3 months after surgery, and both VHI and MPT were significantly better since 1 year after surgery. With bilateral vocal fold injection, the B and A scores improved significantly from 1 month postoperatively compared to unilateral injections(unilateral vs. bilateral injection 1 month post-operation, tB scores=1.42,tA scores=1.51,P<0.05). Conclusions: The long-term efficacy of autologous fat injection in the paraglottic space for the treatment of unilateral vocal fold paralysis was stable. The efficacy of the surgery was related to the amount of fat injected, unilateral or bilateral of the injection.

[Recognition of the membrane anatomy-based laparoscopic assisted right hemicolectomy].

Although it has become a consensus in the field of colorectal surgery to perform radical tumor treatment and functional protection under the minimally invasive concept, there exist many controversies during clinical practice, including the concept of embryonic development of abdominal organs and membrane anatomy, the principle of membrane anatomy related to right hemicolectomy, D3 resection, and identification of the inner boundary. In this paper, we analyzed recently reported literature with high-level evidence and clinical data from the author's hospital to recognize and review the membrane anatomy-based laparoscopic assisted right hemicolectomy for right colon cancer, emphasizing the importance of priority of surgical dissection planes, vascular orientation, and full understanding of the fascial space, and proposing that the surgical planes should be dissected in the parietal-prerenal fascial space, and the incision should be 1 cm from the descending and horizontal part of the duodenum. The surgery should be performed according to a standard procedure with strict quality control. To identify the resection range of D3 dissection, it is necessary to establish a clinical, imaging, and pathological evaluation model for multiple factors or to apply indocyanine green and nano-carbon lymphatic tracer intraoperatively to guide precise lymph node dissection. We expect more high-level evidence of evidence-based medicine to prove the inner boundary of laparoscopic assisted radical right colectomy and a more rigorous consensus to be established.

[Study on changes of voice characteristics after adenotonsillectomy or adenoidectomy in children].

Objective: To study voice changes in children after adenotonsillectomy or adenoidectomy and the relationship with the vocal tract structure. Methods: Fifty patients were recruited in this study prospectively, aged from 4 to 12 years old with the median age of 6. They were underwent adenotonsillectomy or adenoidectomy in Beijing Tongren Hospital, Capital Medical University from July 2019 to August 2020. In the cases, there are 31 males and 19 females. Thirty-six patients underwent adenotonsillectomy and 14 patients underwent adenoidectomy alone. Twenty-two children (13 males, 9 females) with Ⅰ degree of bilateral tonsils without adenoid hypertrophy and no snoring were selected as normal controls. Adenoid and tonsil sizes were evaluated. Subjective changes of voice were recorded after surgery. Moreover, voice data including fundamental frequency(F0), jitter, shimmer, noise to harmonic ratio(NHR), maximum phonation time(MPT), formant frequencies(F1-F5) and bandwidths(B1-B5) of vowel/a/and/i/were analyzed before, 3 days and 1 month after surgery respectively.SPSS 23.0 was used for statistical analysis. Results: Thirty-six patients(72.0%,36/50) complained of postoperative voice changes. The incidence was inversely correlated with age. In children aged 4-6, 7-9, and 10-12, the incidence was 83.3%(25/30), 63.6%(7/11) and 44.4%(4/9) respectively. Voice changes appeared more common in children underwent adenotonsillectomy(77.8%,28/36) than in those underwent adenoidectomy alone(57.1%,8/14), but there was no statistical difference. After operation, for vowel/a/, MPT(Z=2.18,P=0.041) and F2(t=2.13,P=0.040) increased, B2(Z=2.04,P=0.041) and B4(Z=2.00,P=0.046) decreased. For vowel/i/, F2(t=2.035,P=0.050) and F4(t=4.44,P=0.0001) increased, B2(Z=2.36,P=0.019) decreased. Other acoustic parameters were not significantly different from those before surgery. The F2(r=-0.392, P =0.032) of vowel/a/and F2(r=-0.279, P=0.048) and F4 (r=-0.401, P =0.028) of vowel/i/after adenotonsillectomy were significantly higher than those of adenoidectomy alone. Half of patients with postopertive voice changes can recover spontaneously 1 month after surgery. Conclusions: Voice changes in children underwent adenotonsillectomy or adenoidectomy might be related to their changes in formants and bandwidths. The effect of adenotonsillectomy on voice was more significant compared with that of adenoidectomy alone. The acoustic parameters did not change significantly after surgery except MPT.

[Diagnosis and endoscopic treatment of blunt laryngeal trauma with arytenoid injury].

Objective: To investigate the clinical characteristics, diagnosis, endoscopic surgical procedures, and therapeutic effect of blunt laryngeal trauma with arytenoid injury. Methods: We retrospectively reviewed 12 patients who suffered blunt laryngeal trauma with laryngeal mucosa avulsion and arytenoid region injury at the Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital from April 2007 to December 2018. Among the 12 patients, 10 were males, 2 were females, aged from 7 to 48 years old, with a median age of 21 years old. All patients were performed with transoral endoscopic laryngeal microsurgery under general anesthesia. Clinical characteristics, laryngoscopic signs, laryngeal CT, endoscopic surgical findings and procedures, and therapeutic effect were analyzed. The subjective and objective parameters of the voice quality of patients before and after surgery were compared using SPSS 22.0 statistical software by paired T test. Results: All patients had a history of obvious dysphonia immediately after trauma, accompanied by throat pain and hemoptysis without obvious dyspnea and dysphagia. Slight subcutaneous emphysema was found in 3 patients by physical examination. Laryngoscope revealed that 14 sides of vocal folds immobilized, arytenoid and/or ventricular region and posterior glottis mucosa were avulsed in 4 patients within 48 h of injury, and arytenoid cartilage was exposed in 4 sides. The arytenoid and ventricular regions were covered with thick pseudo-membrane or granulation, with abnormal structure in 8 patients with damage of more than 48 h. Intraoperative exploration revealed that there were 17 sides of arytenoid region (bilateral 5 cases, unilateral 7 cases) with varying degrees of injury. There was only limited laceration on three sides of the vocal folds. The lateral ventricular and vocal fold mucosae were avulsed vertically from the arytenoid region and arytenoid cartilage was exposed in 14 sides, among which 6 sides had abnormal arytenoid cartilage morphology and 8 sides had fracture displacement. Laryngeal CT showed irregular thickening of lateral glottis and/or supratroglottic structures in patients with vocal folds immobility, among which asymmetry of arytenoid cartilage structure on both sides in 3 cases and displacement in 2 cases were found. Restoration and microsuture of the fractured arytenoid, perichondrium and avulsion laryngeal mucosa under the direct laryngoscope were performed. The degree of dysphonia was significantly improved immediately after laryngeal microsurgery, the voice significantly improved in G, R, B, A, jitter, shimmer, NHR, and MPT three months after surgery(t=12.792, 12.792, 10.340, 3.276, 2.865, 3.781, 3.173, 3.090, respectively, P<0.05). Except for 1 patient with scar on vocal fold, all the other patients had normal laryngeal morphology and normal vocal fold movement. No laryngeal stenosis was found during the follow-up period. Conclusions: For patients with blunt laryngeal trauma, the injury of arytenoid region and arytenoid cartilage should be evaluated if there is obvious hoarseness, vocal fold immobility, avulsion of ventricular/vocal folds mucosa, or structural abnormality of arytenoid region under laryngoscopic examination. For highly suspected cases, microrphonosurgery under the direct laryngoscope should be performed as soon as possible, which can effectively reduce the occurrence of vocal fold movement disorders and laryngeal scar/stenosis, reconstruct the normal laryngeal structure, and restore the vocal function.

Nitric oxide is involved in phosphorus deficiency-induced cluster-root development and citrate exudation in white lupin.

*White lupin (Lupinus albus) forms specialized cluster roots characterized by exudation of organic anions under phosphorus (P) deficiency. Here, the role of nitric oxide (NO) in P deficiency-induced cluster-root formation and citrate exudation was evaluated. *White lupin plants were treated with the NO donor sodium nitroprusside (SNP) and scavenger or inhibitor of NO synthase under conditions of P deficiency (0 muM) or P sufficiency (50 muM). *Phosphorus deficiency enhanced NO production in primary and lateral root tips, with a greater increase in cluster roots than in noncluster roots. NO concentrations decreased with cluster root development from the pre-emergent stage, through the juvenile stage, to the mature stage. The P deficiency-induced increase in NO production was inhibited by antagonists of NO synthase and xanthine oxidoreductase, suggesting the involvement of these enzymes in NO production. SNP markedly increased the number of cluster roots. Citrate exudation from different root segments in P-deficient roots was positively correlated with endogenous root NO concentrations. *These findings demonstrate differential patterns of NO production in white lupin, depending on root zone, developmental stage and P nutritional status. NO appears to play a regulatory role in the formation of cluster roots and citrate exudation in white lupin under conditions of P deficiency.

[Re-consideration of the construction of quality control system for enhanced recovery after surgery].

The focus on enhanced recovery after surgery (ERAS) is still the implementation of the concept at present, and remains in the stage of disordered and low-quality application because of its difficulties in operation, evaluation and repeatability. The main reason is lack of standard, feasible operation plan and process, which may lead to great heterogeneity and low quality. Therefore, It is urgent to explore and establish the quality control system of ERAS, including foundation, process, terminal and tracking quality control, so as to improve the validity, security, homogeneity and accessibility, and promote the further popularization and application. However, due to the conceptual, systematic, innovative and individual differences, the construction of ERAS standard quality control system will be faced with great difficulties and challenges. ERAS quality control platform and center can only be established gradually by hard work and a lot of researches.

[The expression characteristics and clinical significance of candidate molecular markers in vocal cord leukoplakia].

Objective: To investigate the expression of marker proteins in vocal cord leukoplakia, and to find markers for the early stage of diagnosis and prognosis of precancerous lesions. Methods: The study included 119 cases, 68 cases of vocal cord leukoplakia (22 cases with epithelial simple hyperplasia, 46 cases with epithelial dysplasia), and 51 cases of vocal cords benign lesions(31 cases of vocal cord polyps, 20 cases of Reinke's edema). The expression of p53, Ki-67, p21, Survivin, p16, p27, PTEN, c-Myc and vascular endothelial growth factor (VEGF) in vocal cords leukoplakia were detected, vocal cord benign lesions (vocal cord polyps and Reinke's edema) acted as controls, comparing the expression differences of different pathological tissue. Data was analyzed by SPSS 22.0 software. Results: The expression of p53, p16, Ki-67, VEGF in vocal cord benign lesions and vocal cords leukoplakia with epithelial simple hyperplasia did not show significant differences. There was a grading increase in the positive expression of p53, Ki-67 in the vocal cord leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions and vocal cords leukoplakia with epithelial simple hyperplasia (p53: χ(2)=13.340, P=0.002, Ki-67: χ(2)=53.386, P=0.000). The expression of p27, PTEN, c-Myc in vocal cord benign lesions and vocal cords leukoplakia with epithelial dysplasia did not show significant differences. There was a grading increase in the positive expression of p21 Survivin in vocal cords leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions (P<0.05). Expression of Survivin in vocal cords leukoplakia with mild-moderate epithelial dysplasia showed a significant increase than those in vocal cord benign lesions (P<0.05). The positive expression grade of p21 showed a rising trend (P=0.073) between the different grades of dysplasia. Conclusion: The positive expression grade of p53, Ki-67, p21 Survivin showed an increase in vocal cords leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions, which might be an implication for evaluating the diagnosis and prognosis of precancerous lesions. Expression of p21 was correlated to the degrees of dysplasia and expression of Survivin showed a significant difference in early stage of epithelial dysplasia contrasting to benign lesions.

[Application of stroboscopy and narrow band imaging endoscopy in the diagnosis of vocal cord leukoplakia].

Objective: To investigate the value of stroboscopy and narrow band imaging (NBI)endoscopy in the diagnosis of vocal cord leukoplakia. Methods: Two hundred and forty-six patients with vocal cord leukoplakia who underwent laryngeal microsurgery and diagnosed by histopathology were recruited between August 2014 and July 2016 in this retrospective study. The diagnostic accuracy of stroboscopy and narrow band imaging endoscopy in the diagnosis of vocal cord leukoplakia was compared. SPSS21.0 software was used to analyze the data. Results: A significantly positive correlation was found between the decrease grade of mucosal wave and the histopathological diagnosis(Spearman r=0.526, P<0.01). A significantly positive correlation was found between the lesion classified by detailed morphologic findings of epithelial microvessel and the histopathological diagnosis(Spearman r=0.480, P<0.01). The sensitivity of stroboscopy for detecting severe dysplasia, carcinoma and invasive carcinoma was 92.73%, higher than NBI endoscopy. The specificity of NBI endoscopy was 90.55%, higher than stroboscopy. The results of logistic regression analysis showed: the positive pathological type risk in the group with mucosal waves severely reduced and absent was 3.906 and 19.737 times higher than the group with mucosal waves slightly reduced. In the group with mucosal waves severely reduced and absent, significant difference was observed when combined use of NBI endoscopy(P<0.001, P=0.047). Conclusions: In the diagnosis of vocal cord leukoplakia, stroboscopy is useful for detecting severe dysplasia, carcinoma and invasive carcinoma with high sensitivity. In the group with mucosal waves severely reduced and absent, combined use of NBI endoscopy was able to improve the diagnostic accuracy.

[Clinical and pathological characteristics of vocal fold leukoplakia and influential factors of recurrence and malignancy].

Objective:To investigate the clinical and pathological characteristics of vocal fold leukoplakia and influential factors of recurrence and malignancy. Method:The study included 555 cases of vocal fold leukoplakia. All patients received surgical treatment. The relationship between the clinical and pathological features, and influential factors of recurrence and malignancy were analyzed. Result:The pathological types included squamous epithelial simple hyperplasia in 58.0%, mild hyperplasia in 15.5%, moderate hyperplasia in 10.1%, severe hyperplasia and carcinoma in situ in 8.1%, infiltrative carcinoma in 8.3%. The different pathological types varied among different ages significantly(P<0.01). The tobacco and alcohol abuse had no relationship with pathological types(P>0.05). The more severe the pathology were, the more decreasing of the mucosal waves would be(P<0.01). The pathologic severity had an apparent correlation with p53 positivity and the level of p53 and Ki67 positivity. The p53 positive proportion may increase with the increasing pathological severity(P<0.01), so were the p53 and Ki67 positive levels(P<0.01).Among 232 cases of postoperation follow-ups, 83 cases(35.8%) relapsed while 8 cases(3.4%) malignancy. Bilateral lesions had a higher rate of relapse and malignancy than unilateral lesions(95%CIOR 0.378 ［0.197-0.723］，P<0.01). The relapse and malignancy had a relationship with the pathologic severity. The incidence of disease recurrence and malignancy were positively correlated with pathological severity(P<0.05). p16 positive patients relapsed for more times(P<0.01) and with an uprising tendency of relapse and malignancy（P>0.05）. Conclusion:Pathological types of vocal fold leukoplakia are different. The older men, decreasing of mucosal wave of vocal folds and bilateral lesions were very important factors to predict disease severity. p53 and Ki67 positive rating and pathological severity were positively correlated. The bilateral lesions, pathological severity and p16 positivity had a tendency to increasing relapse and malignancy.

Chemical cross-linking of hemoglobin H. A possible approach to introduce cooperativity and modification of its oxygen transport properties.

Native and reconstituted hemoglobin H molecules were cross-linked with glutaraldehyde at pH values close to the physiological. The Schiff base adducts were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis before and after reduction with sodium borohydride. The major component had a molecular weight of about 31 000 which corresponded to the dimeric species of the beta subunit. In contrast to the native protein, which has very high oxygen affinity and no heme-heme interaction or 2,3-diphosphoglyceric acid effect, the modified hemoglobin H molecules showed cooperative oxygen binding, decreased oxygen affinity and a noticeable 2,3-diphosphoglyceric acid effect.

Effects of lead contamination on the clonal propagative ability of Phragmites australis (common reed) grown in wet and dry environments.

Clonal propagation is important for the survival and maintenance of the common reed Phragmites australis. Pot culture experiments were conducted to investigate the effects of lead (Pb) concentration (0, 500, 1500, 3000, 4500 mg·kg(-1) ) and water stress on the clonal reproductive ability of this species. The Pb concentration found in plant organs, in decreasing order, was roots >shoots >rhizomes. There was a negative relationship between the growth of clonal propagative modules (excluding axillary shoot buds) and Pb concentrations, which caused a decrease in biomass, rhizome growth and number of axillary and apical rhizome buds. Daughter axillary shoots exhibited a tolerance strategy, with no significant change in their number; the axillary and apical rhizome buds, daughter apical rhizome shoots and rhizomes exhibited compensatory growth during the late stage of Pb (excluding 4500 mg·kg(-1) ) treatment in a wet environment. Pb applications above 500 mg·kg(-1) reduced these parameters significantly in the drought treatment, except for the number of axillary shoot buds, which did not change. Our results indicate that clonal propagative resistance to Pb contamination can occur via tolerance strategies, compensatory growth and a Pb allocation strategy, enabling these reeds to maintain population stability in wet environments. However, clonal modular growth and reproductive ability were inhibited significantly by the interaction between drought and Pb, which would cause a decline in P. australis populations in a dry environment. Lead concentrations of 4500 and 500 mg·kg(-1) in soils might meet or exceed the Pb tolerance threshold of clonally propagated reeds in wet and dry environments, respectively.

Genomic organization and characterization of a three-gene rat adult beta-globin haplotype.

The isolation and detailed characterization of a three-beta-globin gene (GloB) haplotype in the Sprague-Dawley (S-D) rat is described. An enriched library, lambda SDHelib, was screened with a human GloB probe, humbg44, and from which a beta minor gene, Rathbbz, was isolated, sequenced and characterized. A S-D rat GloB-specific probe, Ratbgze12, derived from the Rathbbz gene, was then used to screen a S-D rat genomic library, lambda SDglib. The clone T1510 was isolated and identified to include the entire Rathbbz gene and part of another GloB gene, Rathbby, which was 5' upstream from Rathbbz. Chromosomal walking upstream using the riboprobe, rnaT71, led to the isolation of an overlapping clone, Ta49, which was shown to include two full-length GloB genes; the most 5' was Rathbbx followed by Rathbby. Sequence data suggests that Rathbbx is a beta major gene, whereas Rathbby is a hybrid gene of Rathbbx and Rathbbz. Genomic hybridization confirmed this particular three-gene haplotype in the S-D rat. This haplotype, a1, may be the prototype of the GloB cluster in rat.

Inhibition of alcohol dehydrogenases by thiol compounds.

2-Mercaptoethanol is a strong inhibitor of LADH. The inhibitory effect is likely due to the binding of the SH group to the enzymatic zinc ion. Various thiol compounds do not inhibit YADH and it is suggested that the zinc atoms involved in the catalytic mechanism of LADH and YADH may have different structural arrangements and that these zinc atoms in YADH may not be blocked by thiol compounds. Thiol compounds also quench the enhanced fluorescence of LADH-NADH in a pH-dependent manner. At pH 9.2, the binding of coenzyme to LADH is replaced by 2-mercaptoethanol, whilst at pH 7.3, it further quenches the fluorescence of NADH-LADH. This quenching of fluorescence is likely attributed to a conformational change and energy transfer upon binding of 2-mercaptoethanol to the LADH-NADH complex. Complete reversal of the inhibitory effect of thiol compounds on LADH can be obtained by dialysis.

Expression of MHC class I antigen in Morris rat hepatoma and normal liver.

Expression of major histocompatibility complex (MHC) class I antigen in Morris rat hepatoma 7777 and normal rat liver tissues was studied by immunohistochemical techniques, Western blot and radiobinding assay. It was found that hepatoma tissue displayed a pattern of enhanced MHC class I antigen expression compared with normal liver. This phenomenon may represent an uncommon pattern of MHC class I antigen expression of liver tumor. The influence of enhanced MHC class I antigen expression on the development and spread of tumors as well as the possible mechanisms of this enhancement are discussed.

Norcantharidin inhibits growth of human HepG2 cell-transplanted tumor in nude mice and prolongs host survival.

In this study, norcantharidin was compared with adriamycin and mitomycin C for its inhibitory action in the growth of cultured human hepatocellular carcinoma HepG2 cells. The IC50 of adriamycin and mitomycin C on HepG2 cells was 7.3 microM and 27 microM, respectively, whereas the IC50 of norcantharidin for inhibiting the growth of HepG2 cells was as high as 1900 microM. After HepG2 tumor-bearing nude mice were treated with 12 daily intraperitoneal injections of norcantharidin (2 mg/kg), the increase in tumor size was significantly slower than that of untreated controls. The mean survival time of untreated tumor-bearing nude mice was 129 days, whereas in the tumor-bearing nude mice treated with norcantharidin, the mean survival time was significantly prolonged to 194 days (P < 0.0001). It is concluded that norcantharidin may have a potential role in the treatment of human hepatocellular carcinoma.

Effects of IFN-gamma, TNF-alpha and EGF on the expression of HLA class I antigen and the proliferation of human hepatocellular carcinoma HepG2 cells.

In this study, the effects of IFN gamma, TNF alpha and EGF on the expression of HLA class I antigen and the proliferation of human hepatocellular carcinoma-HepG2 cells were investigated. In response to IFN gamma or TNF alpha stimulation, the expression of HLA class I mRNA in HepG2 cells was increased by 2-4 fold. Cell surface HLA class I antigen was also increased, but in comparison, the increase was not as high as HLA class I mRNA expression. This is probably due to the limitation of protein translational and post-translational processing. The enhancing effect of EGF on cell surface HLA class I antigen could be noted but was not very significant. IFN gamma and TNF alpha could also inhibit the proliferation of HepG2 cells. Interestingly, the effect of EGF on the proliferation of HepG2 cells depended on its concentration. At low concentrations, EGF increased cell proliferation in terms of thymidine incorporation. However, if the concentration of EGF was relatively high, it could also exert an inhibitory effect on thymidine incorporation into HepG2 cells. The remarkable morphological alteration was observed when HepG2 cells were exposed to EGF at concentrations higher than 5 ng/ml. This morphological alteration might be associated with the inhibitory effect of EGF at high concentrations on the proliferation of HepG2 cells.