[Study on the mechanism of early pancreatic exocrine function changes in severely scalded rats]

Objective: To explore the mechanism of early pancreatic exocrine function changes in severely scalded rats. Methods: The experimental research methods was used. Eighty male Sprague-Dawley rats aged 7-8 weeks were divided into simple sham injury group (n=8), sham injury+cholecystokinin octapeptide (CCK8) group (n=8), severe scald+CCK8 group (n=32), and extremely severe scald+CCK8 group (n=32) by the random number table, which were treated accordingly. Immediately after injury of rats in the 2 sham injury groups and 1, 2, 3, and 7 days after injury of rats in the 2 scald groups, the improved methods including pancreatic duct puncture and catheterization were used to dynamically collect the pancreatic-bile juice (PBJ) of rats. The PBJ secretory volume within 1 h was recorded, and the content of pancreatic lipase, α-amylase, and trypsin in PBJ was detected by enzyme-linked immunosorbent assay (ELISA), and the number of samples was 8. The femoral venous blood was collected, and the concentrations of pancreatic lipase and α-amylase in serum were detected by standard colorimetry to reflect their activity (n=8). The pancreatic tissue was extracted, and the levels of interleukin-1β (IL-1β) and IL-6 in pancreatic tissue were detected by ELISA (n=8), the expression of hypoxia-inducible factor 1α (HIF-1α) in pancreatic tissue was detected by immunofluorescence method, and the histopathological changes in pancreatic tissue were observed by hematoxylin-eosin staining, the severity of pancreatic tissue injury in the 2 scald groups was evaluated by modified Schmidt method (n=6), and the ultrastructure of acinar cells in pancreatic tissue was observed by transmission electron microscopy. Data were statistically analyzed with analysis of variance for factorial design, Tukey test, independent sample t test, and least significant difference test. Results: Compared with the PBJ secretory volume (0.740±0.030) mL in the pancreatic tissue of rats in simple sham injury group within 1 h immediately after injury, the (0.823±0.033) mL in sham injury+CCK8 group was significantly increased (t=4.92, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the PBJ secretory volume of rats within 1 h in severe scald+CCK8 group ((0.681±0.024), (0.608±0.056), (0.525±0.025), and (0.720±0.044) mL) and extremely severe scald+CCK8 group ((0.540±0.025), (0.406±0.021), (0.475±0.036), and (0.690±0.018) mL) was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the PBJ secretory volume of rats within 1 h in extremely severe scald+CCK8 group was significantly decreased on 1 and 2 days after injury (P<0.05). Compared with that of rats in simple sham injury group immediately after injury, the content of pancreatic lipase, α-amylase, and trypsin in PBJ of rats in sham injury+CCK8 group immediately after injury was significantly increased (with t values of 4.56, 3.30, and 4.99, respectively, P<0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the content of pancreatic lipase and α-amylase in PBJ of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group was significantly decreased on 1, 2, 3, and 7 days after injury (P<0.05), the trypsin content in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 2 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the content of pancreatic lipase in PBJ of rats in extremely severe scald+CCK8 group was significantly decreased on 1, 2, and 3 days after injury (P<0.05), and the content of α-amylase and trypsin in PBJ was significantly decreased on 1 and 2 days after injury (P<0.05). There were no statistically significant differences in the activities of pancreatic lipase and α-amylase in serum of rats among the 4 groups at various time points after injury (P>0.05). Compared with that of rats in sham injury+CCK8 group immediately after injury, the levels of IL-1β in pancreatic tissue of rats in severe scald+CCK8 group on 1, 2, and 3 days after injury and in extremely severe scald+CCK8 group on 1, 2, 3, and 7 days after injury were significantly increased (P<0.05), and the levels of IL-6 in pancreatic tissue of rats in severe scald+CCK8 group and extremely severe scald+CCK8 group were significantly increased on 1, 2, 3, and 7 days after injury (P<0.05). Compared with that in severe scald+CCK8 group, the IL-1β level in pancreatic tissue of rats in extremely severe scald+CCK8 group was significantly increased on 2 and 3 days after injury (P<0.05), and IL-6 level in pancreatic tissue was significantly increased on 2 days after injury (P<0.05). The expression levels of HIF-1α in pancreatic tissue of rats in simple sham injury group and sham injury+CCK8 group immediately after injury were lower; and compared with that in sham injury+CCK8 group immediately after injury, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups increased to a certain extent at different time points after injury, and the expression position was transited from the edge of the pancreatic tissue to the whole pancreas, the expression levels of HIF-1α in pancreatic tissue of rats in the 2 scald groups tended to be normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the proportion of acinar cell cytoplasm in pancreatic tissue of rats in sham injury+CCK8 group was increased; and with the increase of time after injury, edema, hemorrhage, necrosis, and inflammatory infiltration appeared in pancreatic tissue of rats in the 2 scald groups. Compared with that in severe scald+CCK8 group, the scores of edema, inflammatory cell infiltration, bleeding, and necrosis in pancreatic tissue of rats in extremely severe scald+CCK8 group were increased to varying degrees at various time points after injury, and the scores of pancreatic tissue of rats in the 2 scald groups basically recovered to normal on 7 days after injury. Compared with that in simple sham injury group immediately after injury, the number of enzyme granules in acinar cells of pancreatic tissue of rats in sham injury+CCK8 group was increased, and with the increase of time after injury, the enzyme granules in acinar cells of rats in the 2 scald groups were gradually reduced basically. Conclusions: The exocrine functions of pancreas, such as synthesis and secretion of pancreatic enzymes, are decreased in the early stage in severely scalded rats. And the greater the scalded area, the more significant the decline of pancreatic exocrine function. This change may be related to hypoxic injury and inflammation in pancreatic tissue after severe scald.

[The efficacy and safety of intravenous sucrose iron therapy for recurrent iron deficiency anemia]

Objective: To evaluate the efficacy and safety of intravenous iron supplementation in patients with recurrent iron deficiency anemia (IDA) . Methods: This retrospective analysis of 90 patients with recurrent IDA from May 2012 to December 2021 was conducted, comparing the efficacy and safety of the intravenous iron therapy group and the oral iron therapy group. Results: Among the 90 patients with recurrent IDA, 20 were males and 70 were females, with a median age of 40 (range: 14-85) years. A total of 60 patients received intravenous iron supplementation and 30 received oral iron supplementation. The hematologic response rates in the intravenous iron group were significantly higher than those in the oral iron group at 4 and 8 weeks after treatment [80.0% (48/60) vs 3.3% (1/30) and 96.7% (58/60) vs 46.7% (14/30), all P<0.001, respectively]. The median increase in hemoglobin levels was also significantly higher in the intravenous iron group than in the oral iron group [38 (4, 66) g/L vs 7 (1, 22) g/L at week 4 and 44.5 (18, 80) g/L vs 19 (3, 53) g/L at week 8, all P<0.001]. The intravenous iron group had a significantly higher proportion of patients who achieved normal hemoglobin levels than the oral iron group (55.0% vs 0 and 90% vs 43.3%, all P<0.001, respectively). Iron metabolism indicators were tested before and after 8 weeks of treatment in 26 and 7 patients in the intravenous and oral iron groups, respectively. The median increase in serum ferritin (SF) levels in the intravenous iron group 8 weeks after treatment was 113.7 (49.7, 413.5) μg/L, and 54% (14/26) of these patients had SF levels of ≥100 μg/L, which was significantly higher than the median increase in SF levels in the oral iron group [14.0 (5.8, 84.2) μg/L, t=4.760, P<0.001] and the proportion of patients with SF levels of ≥100 μg/L (P=0.013). The incidence of adverse reactions was 3.3% (2/60) in the intravenous iron group, which was significantly lower than that in the oral iron group [20.0% (6/30), P=0.015]. Conclusion: Intravenous iron supplementation is more effective for hematologic response, faster hemoglobin increase, and higher iron storage replenishment rates compared with oral iron supplementation in patients with recurrent IDA, and it is well tolerated by patients.

[Establishment and application of the ten-fold rehydration formula for emergency resuscitation of pediatric patients after extensive burns]

Objective: To investigate the scientificity and feasibility of the ten-fold rehydration formula for emergency resuscitation of pediatric patients after extensive burns. Methods: A retrospective observational study was conducted. The total burn area of 30%-100% total body surface area (TBSA) and body weight of 6-50 kg in 433 pediatric patients (250 males and 183 females, aged 3 months to 14 years) with extensive burns who met the inclusion criteria and admitted to the burn departments of 72 Class A tertiary hospitals were collected. The 6 319 pairs of simulated data were constructed after pairing each body weight of 6-50 kg (programmed in steps of 0.5 kg) and each total burn area of 30%-100% TBSA (programmed in steps of 1%TBSA). They were put into three accepted pediatric rehydration formulae, namely the commonly used domestic pediatric rehydration formula for burn patients (hereinafter referred to as the domestic rehydration formula), the Galveston formula, and the Cincinnati formula, and the two rehydration formulae for pediatric emergency, namely the simplified resuscitation formula for emergency care of patients with extensive burns proposed by the World Health Organization's Technical Working Group on Burns (TWGB, hereinafter referred to as the TWGB formula) and the pediatric ten-fold rehydration formula proposed by the author of this article--rehydration rate (mL/h)=body weight (kg) × 10 (mL·kg-1·h-1) to calculate the rehydration rate within 8 h post injury (hereinafter referred to as the rehydration rate). The range of the results of the 3 accepted pediatric rehydration formulae ±20% were regarded as the reasonable rehydration rate, and the accuracy rates of rehydration rate calculated using the two pediatric emergency rehydration formulae were compared. Using the maximum burn areas (55% and 85% TBSA) corresponding to the reasonable rehydration rate calculated by the pediatric ten-fold rehydration formula at the body weight of 6 and 50 kg respectively, the total burn area of 30% to 100% TBSA was divided into 3 segments and the accuracy rates of the rehydration rate calculated using the 2 pediatric emergency rehydration formulae in each segment were compared. When neither of the rehydration rates calculated by the 2 pediatric emergency rehydration formulae was reasonable, the differences between the two rehydration rates were compared. The distribution of 433 pediatric patients in the 3 previous total burn area segments was counted and the accuracy rates of the rehydration rate calculated using the 2 pediatric emergency rehydration formulae were calculated and compared. Data were statistically analyzed with McNemar test. Results: Substitution of 6 319 pairs of simulated data showed that the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula was 73.92% (4 671/6 319), which was significantly higher than 4.02% (254/6 319) of the TWGB formula (χ2=6 490.88,P<0.05). When the total burn area was 30%-55% and 56%-85% TBSA, the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula were 100% (2 314/2 314) and 88.28% (2 357/2 670), respectively, which were significantly higher than 10.98% (254/2 314) and 0 (0/2 670) of the TWGB formula (with χ2 values of 3 712.49 and 4 227.97, respectively, P<0.05); when the total burn area was 86%-100% TBSA, the accuracy rates of the rehydration rates calculated by the pediatric ten-fold rehydration formula and the TWGB formula were 0 (0/1 335). When the rehydration rates calculated by the 2 pediatric emergency rehydration formulae were unreasonable, the rehydration rates calculated by the pediatric ten-fold rehydration formula were all higher than those of the TWGB formula. There were 93.07% (403/433), 5.77% (25/433), and 1.15% (5/433) patients in the 433 pediatric patients had total burn area of 30%-55%, 56%-85%, and 86%-100% TBSA, respectively, and the accuracy rate of the rehydration rate calculated using the pediatric ten-fold rehydration formula was 97.69% (423/433), which was significantly higher than 0 (0/433) of the TWGB formula (χ2=826.90, P<0.05). Conclusions: The application of the pediatric ten-fold rehydration formula to estimate the rehydration rate of pediatric patients after extensive burns is more accurate and convenient, superior to the TWGB formula, suitable for application by front-line healthcare workers that are not specialized in burns in pre-admission rescue of pediatric patients with extensive burns, and is worthy of promotion.

[Research advances on the role and mechanism of epidermal stem cells in skin wound repair]

Epidermal stem cells play an pivotal role in skin self-renewal, wound repair, and re-epithelialization process. The emergence of new technologies and concepts such as single-cell sequencing and gene knockout further revealed a new mechanism of epidermal stem cells in epidermal self-renewal and wound repair, providing new ideas for wound repair. In this review, the mechanisms of proliferation, differentiation, and migration of epidermal stem cells are discussed. Combined with the analysis of researches on stem cell heterogeneity and cell plasticity, the physiological function of epidermal stem cells can be further understood. The application advances of epidermal stem cells in wound repair is also summarized, which would provide some advice for workers engaged in clinical and basic research on wound repair.

Transcriptomic and Metabolomic Analyses Provide Insights into the Formation of the Peach-like Aroma of Fragaria nilgerrensis Schlecht. Fruits

Fragaria nilgerrensis Schlecht. is a wild diploid strawberry species. The intense peach-like aroma of its fruits makes F. nilgerrensis an excellent resource for strawberry breeding programs aimed at enhancing flavors. However, the formation of the peach-like aroma of strawberry fruits has not been comprehensively characterized. In this study, fruit metabolome and transcriptome datasets for F. nilgerrensis (HA; peach-like aroma) and its interspecific hybrids PA (peach-like aroma) and NA (no peach-like aroma; control) were compared. In total, 150 differentially accumulated metabolites were detected. The K-means analysis revealed that esters/lactones, including acetic acid, octyl ester, δ-octalactone, and δ-decalactone, were more abundant in HA and PA than in NA. These metabolites may be important for the formation of the peach-like aroma of F. nilgerrensis fruits. The significantly enriched gene ontology terms assigned to the differentially expressed genes (DEGs) were fatty acid metabolic process and fatty acid biosynthetic process. Twenty-seven DEGs were predicted to be associated with ester and lactone biosynthesis, including AAT, LOX, AOS, FAD, AIM1, EH, FAH, ADH, and cytochrome P450 subfamily genes. Thirty-five transcription factor genes were predicted to be associated with aroma formation, including bHLH, MYB, bZIP, NAC, AP2, GATA, and TCPfamily members. Moreover, we identified differentially expressed FAD, AOS, and cytochrome P450 family genes and NAC, MYB, and AP2 transcription factor genes that were correlated with δ-octalactone and δ-decalactone. These findings provide key insights into the formation of the peach-like aroma of F. nilgerrensis fruits, with implications for the increased use of wild strawberry resources.

[Prevalence and risk factors of deep venous thrombosis of lower extremity in patients with stage and pressure ulcers on admission]

Objective: To investigate the incidence and risk factors of deep venous thrombosis (DVT) of lower extremity in patients with stage Ⅲ and Ⅳ pressure ulcer on admission. Methods: A retrospective case series study was conducted. A total of 241 patients with stage Ⅲ and Ⅳ pressure ulcers who met the inclusion criteria and were discharged from the Department of Wound Repair of the First People's Hospital of Zhengzhou from January 1, 2015 to December 31, 2019 were enrolled in this study, including 134 males and 107 females, aged 22 to 93 years, with a median age of 68 years; 37 patients were with stage Ⅲ pressure ulcers and 204 patients were with stage Ⅳ pressure ulcers. The DVT occurrence of patients was recorded. According to whether DVT of lower extremity veins was diagnosed by color Doppler ultrasound within 48 h after admission or not, the patients were divided into DVT group (n=37) and non-DVT group (n=204). Data of patients in the two groups were collected and compared, including gender, age, duration of pressure ulcer, time in bed, and combination with diabetes, hypertension, coronary heart disease, cerebral infarction, pneumonia, sepsis/septic shock, and paraplegia, and the plasma D-dimer level and Caprini score within 24 h after admission. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. The indicators with statistically significant differences between the two groups were analyzed with multivariate logistic regression analysis to screen the independent risk factors influencing the DVT of lower extremity in 241 patients with stage Ⅲ and Ⅳ pressure ulcers on admission. Results: The incidence of DVT of lower extremity was 15.4% (37/241), of which 86.5% (32/37) were asymptomatic DVT. Among the DVT of 46 lower limbs, only 29 involved the inferior genicular veins, accounting for 63.0%. There were no statistically significant differences in gender, duration of pressure ulcer, combination with diabetes, hypertension, coronary heart disease, cerebral infarction, pneumonia, and sepsis/septic shock of patients between the two groups (P>0.05), while there were statistically significant differences in age, time in bed, combination with paraplegia, the plasma D-dimer level and Caprini score of patients between the two groups(t=-3.19, Z=-2.04, χ2=4.44, Z=-3.89, t=-2.14, respectively, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that age and plasma D-dimer level were independent risk factors influencing the DVT of lower extremity in 241 patients with stage Ⅲ and Ⅳ pressure ulcers on admission (with odds ratios of 1.03 and 1.18, respectively, with 95% confidence intervals of 1.00-1.06 and 1.05-1.33, respectively, P<0.05 or P<0.01). Conclusions: The patients with stage Ⅲ and Ⅳ pressure ulcers have a higher incidence of DVT on admission, with age and plasma D-dimer level being the independent risk factors for DVT of lower extremity. It is necessary to pay attention to the targeted screening of DVT and education of its prevention.

[Establishment and application of the tenfold rehydration formula for emergency resuscitation of adult patients after extensive burns]

Objective: To explore the scientificity and feasibility of the tenfold rehydration formula for emergency resuscitation of adult patients after extensive burns. Methods: A retrospective observational study was conducted. The total burn area (30%-100% total body surface area (TBSA)) and body weight (45-135 kg) of 170 adult patients (135 males and 35 females, aged (42±14) years) with extensive burns admitted to the Fourth Medical Center of PLA General Hospital from December 2016 to December 2019 were collected. The 6 461 pairs of simulated data obtained after pairing each body weight in 45 to 135 kg (programmed in steps of 1 kg) with each area in 30% to 100% TBSA (programmed in steps of 1%TBSA) were plugged into four recognized rehydration formulas--Parkland's formula, Brooke's formula, the 304th PLA Hospital formula, and the Third Military Medical University formula and two emergency rehydration formulas--the simplified first aid resuscitation plan for extensive burn patients proposed by the World Health Organization's Technical Working Group on Burns (TWGB, hereinafter referred to as the TWGB formula) and the tenfold rehydration formula proposed by the author of this article to calculate the rehydration rate within 8 hours after injury (hereinafter referred to as the rehydration rate), with results being displayed by a programming step of 10%TBSA for the total burn area. Taking the calculation results of four recognized rehydration formulas as the reasonable rehydration rate, the accuracy of rehydration rates calculated by two emergency rehydration formulas were calculated and compared. The body weight of 45-135 kg was divided into three segments by the results of maximum body weight at a reasonable rehydration rate calculated by the tenfold rehydration formula when the total burn area was 30% and 100% TBSA, respectively. The accuracy of rehydration rate calculated by two emergency rehydration formulas in each body weight segment was compared. When the rehydration rates calculated by two emergency rehydration formulas were unreasonable, the differences in rehydration rates between the two were compared. Statistical distribution of the aforementioned three body weight segments in the aforementioned 170 patients was counted. Using the total burn area and body weight data of the aforementioned 170 patients, the accuracy of rehydration rate calculated by two emergency rehydration formulas was calculated and compared as before. Data were statistically analyzed with McNemar test. Results: When the total burn area was 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% TBSA, respectively, and the body weight was 45-135 kg, the rehydration rates calculated by two emergency rehydration formulas did not exceed the maximum of the calculated results of four recognized rehydration formulas; the rehydration rate calculated by the TWGB formula did not change accordingly with total burn area, while the rehydration rate calculated by the tenfold rehydration formula did not change accordingly with body weight. Substituting 6 461 pairs of simulated data showed that the accuracy of rehydration rate calculated by the tenfold rehydration formula was 43.09% (2 784/6 461), which was significantly higher than 2.07% (134/6 461) of the TWGB formula, χ2=2 404.80, P<0.01. When the body weights were 45-62 kg and 63-93 kg, the accuracy rates of rehydration rate calculated by the tenfold rehydration formula were 100% (1 278/1 278) and 68.42% (1 506/2 201), respectively, which were significantly higher than 0 (0/1 278) and 0.05% (1/2 201) of the TWGB formula, χ2=1 276.00, 1 501.01, P<0.01; when the body weight was 94-135 kg, the accuracy rate of rehydration rate calculated by the tenfold rehydration formula was 0 (0/2 982), which was significantly lower than 4.46% (133/2 982) of the TWGB formula, χ2=131.01, P<0.01. When the rehydration rates calculated by two emergency rehydration formulas were both unreasonable, the rehydration rate calculated by the tenfold rehydration formula was greater than that calculated by the TWGB formula in most cases, accounting for 79.3% (2 808/3 543). Among the 170 patients, the proportions of those weighing 45-62, 63-93, and 94-135 kg were 25.29% (43/170), 65.88% (112/170), and 8.82% (15/170), respectively. Among the 170 patients, the accuracy rate of rehydration rate calculated by the tenfold rehydration formula was 69.41% (118/170), which was significantly higher than 3.53% (6/170) of the TWGB formula, χ2=99.36, P<0.01. Conclusions: Applying the tenfold rehydration formula to calculate the emergency rehydration rate in adults after extensive burns is simpler than four recognized rehydration formulas, and is superior to the TWGB formula. The tenfold rehydration formula is suitable for the front-line medical staffs that are not specialized in burns in pre-admission rescue of adult patients with extensive burns, which is worth popularizing.

Experiences of international medical students enrolled in Chinese medical institutions towards online teaching during the COVID-19 pandemic

Introduction

. The COVID-19 pandemic has forced the world to pause. One hundred and eighty-eight countries have imposed countrywide school closures, affecting more than 1.5 billion children and youths. The majority of academic leaders are currently encouraging online education to resolve this crisis. This study aimed to investigate international medical students' (IMS) experiences of online teaching during the COVID-19 pandemic.

Methods

Data were collected online using a validated questionnaire and one open-ended question, presented on the Google forms platform. The study attracted responses from 1,107 IMS volunteer participants. IBM SPSS v. 25, GraphPad Prism v. 9, and MindManager v. 2018 were used for data analysis. All variables were subjected to descriptive statistical analysis. The Mann-Whitney U test was used in subgroup analysis and the Kruskal-Wallis test was also applied for year-wise comparisons. Open-ended text responses were analyzed qualitatively, extracting themes by which responses were classified.

Results

Among 1,107 respondents, a total of 67.8% were males, and the majority (63.1%) of the IMS were in the age group of 21-23 years. The results show that more than half of the respondents reported their Internet connection quality as poor to average. Poor Internet connection severely affected IMS online learning experience. Persistent and recurrent issues with Internet access became a significant concern for IMS. Lack of electricity is one of the factors that can contribute to poor learning output and dissatisfaction with online teaching. IMS perceive online medical education as unhelpful in several phases of the training, such as improving their clinical skills, knowledge, and discussion skills.

Conclusions

During these unprecedented periods, online teaching has allowed medical education to continue. However, IMS are generally dissatisfied with online teaching. Medical students must visualize the human body, so supportive technologies are important to compensate for the lack of clinical practices. Medical institutions may need to invest in faculty training programs and continually adjust to enhance the content of online training and international partnerships. A switch from conventional face-to-face teaching to a fully functional virtual education framework in the medical education field will take time and experience.

Promoting Sustainable Development in School Classrooms: Using Reciprocal Teaching in Mathematics Education

Many elementary students face difficulties in solving word-based, mathematical problems. This study explores using the reciprocal teaching instructional strategy for word-based, mathematical problems at the elementary level. We used a quasiexperimental research design for this study to address the reciprocal teaching environment design, implementation, and evaluation at elementary level mathematics education. Two sixth grade model classes, A & B, of a public secondary school from the district of Okara, Punjab, Pakistan, were selected for this study. Reciprocal teaching for mathematics appears to be an essential strategy for nurturing a more in-depth understanding of the text of mathematical word problems at the elementary level. This instructional approach could enhance an extraordinary level of skill in critical thinking, reasoning, and understanding.

[Application of rigid curved laryngoscope in the examination of hypopharynx and the treatment of early hypopharyngeal cancer]

Objective: To evaluate the efficacy of curved suspension laryngoscope assistant transoral surgery (CLATOS) in the examination of hypopharynx, and diagnosis and surgery of early hypopharyngeal carcinoma. Methods: Thirty-four patients who underwent detailed examination for lower part of hypopharynx and surgery for early hypopharyngeal carcinoma with CLATOS technique in the Second Affiliated Hospital of Harbin Medical University from January 2019 to January 2020 were analyzed retrospectively. The age ranged from 42 to 74 years old including 28 males and 6 females. Among them, 25 patients complaining of foreign body sensation in the pharynx for more than half a year with a poor exposure of the lower pharynx in the examination with flexible laryngoscope in the outpatient department were admitted to the hospital for the further examination with rigid curved laryngoscopy and 9 patients with stage T1-2 hypopharyngeal squamous cell carcinoma were operated with CLATOS technique. Preoperative, intraoperative and postoperative data were analized. Results: One case of squamous cell carcinoma in esophageal entrance (T1N0M0) and one case of carcinoma in pyriform sinus (T1N0M0) with cervical esophageal carcinoma (T1N0M0) were found in the 25 patients with foreign body sensation in the pharynx. En bloc resection of cancer was obtained in 9 patients with stage T1-2 hypopharyngeal carcinomas and 2 of them underwent tracheotomy. One patient with T1 retrocricoid carcinoma was found to have a carcinoma in situ at the lower part of posterior hypopharyngeal wall in the examination during follow-up, which was resected simultaneously. Postoperatively this patient developed a stenosis in the esophageal entrance, which was dilated twice until swallowing normally. Two patients of T2N0M0 and one of T2N1M0 underwent bilateral neck lymph node dissection just after the removal of primary tumors. During follow-up, none of the 9 patients showed tumor recurrence and complications such as dysphonia and dyspnea. Conclusion: CLATOS technique can provide a promising way in the examination of hypopharynx and the detection of early lesions of hypopharynx and esophageal entrance, and this technique has also the advantages such as full visual angle and easy operation for the resection of early hypopharyngeal carcinoma. The quality of life of patients can be improved while the tumor is removed en bloc with this technique.

Robust neutralization assay based on SARS-CoV-2 S-protein-bearing vesicular stomatitis virus (VSV) pseudovirus and ACE2-overexpressing BHK21 cells

The global pandemic of coronavirus disease 2019 (COVID-19) is a disaster for human society. A convenient and reliable neutralization assay is very important for the development of vaccines and novel drugs. In this study, a G protein-deficient vesicular stomatitis virus (VSVdG) bearing a truncated spike protein (S with C-terminal 18 amino acid truncation) was compared to that bearing the full-length spike protein of SARS-CoV-2 and showed much higher efficiency. A neutralization assay was established based on VSV-SARS-CoV-2-Sdel18 pseudovirus and hACE2-overexpressing BHK21 cells (BHK21-hACE2 cells). The experimental results can be obtained by automatically counting the number of EGFP-positive cells at 12 h after infection, making the assay convenient and high-throughput. The serum neutralizing titer measured by the VSV-SARS-CoV-2-Sdel18 pseudovirus assay has a good correlation with that measured by the wild type SARS-CoV-2 assay. Seven neutralizing monoclonal antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 S protein were obtained. This efficient and reliable pseudovirus assay model could facilitate the development of new drugs and vaccines.

MicroRNA-206 inhibits tumor metastasis of nasopharyngeal carcinoma through targeting G6PD

Nasopharyngeal carcinoma (NPC) is a main type of otolaryngological malignancy. In many cancers, miR-206 functions as a tumor suppressor, suppressing cell proliferation, migration and invasion. The purpose of this study was to explore how miR-206 worked on cell metastasis in NPC. The mRNA levels of miR-206 and G6PD were determined in NPC tissues and cell lines by RT-qPCR and Western blot. Transwell assay was applied to evaluate the migratory and invasive capacities. Dual luciferase reporter assay was employed to confirm that miR-206 mediated the expression of G6PD in C666-1 cells. In this study, miR- 206 was downregulated, whereas G6PD was upregulated in NPC tissues and cell lines. In addition, G6PD was identified as a direct target gene of miR-206 in C666-1 cells. The expression of G6PD was mediated by miR-206, which could partially reverse the inhibitory effects of miR-206 on the migration, invasion and EMT in C666-1 cells. In conclusion, miR-206 regulated the migratory, invasive and EMT abilities through directly targeting the 3'-UTR of G6PD mRNA in C666-1 cells. The newly identified miR-206/G6PD axis provides novel insight into the pathogenesis of nasopharyngeal carcinoma.

[Changes of insulin secretion and its signal transduction mechanism at early stage of severe scald in rats]

Objective: To observe the changes of insulin secretion in the early stage of severe scald in rats, and to explore its signal transduction mechanism. Methods: Twenty-four male Wistar rats aged 7 weeks were divided into sham injury alone (SIA) group, sham injury+ BPV (HOpic) (SIB) group, scald alone (SA) group, and scald+ BPV (HOpic) (SB) group using the random number table, with 6 rats in each group. Full-thickness scald of 50% total body surface area was inflicted in rats of SA and SB groups by a 6-s immersion of the abdomen and a 12-s immersion of the back in 94 ℃ hot water. Rats in SIA and SIB groups received sham injuries through immersion of the back and abdomen in 37 ℃ warm water for 6 and 12 seconds respectively. From 0 (immediately) to 2 day (s) after injury, the rats in groups SB and SIB were intraperitoneally injected with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway enhancer BPV (HOpic) solution (0.5 mg/mL) at the dosage of 0.6 mg/kg once a day, and the rats in groups SA and SIA were intraperitoneally injected with the same volume of dimethyl sulfoxide once a day. At post injury hour (PIH) 72, the tail blood of rats was sampled for measuring fasting blood glucose (FBG) with a glucometer, and the pancreatic tissue samples of rats was harvested for observing the pathological manifestations of islets by hematoxylin-eosin staining, counting the docked granules per 10 μm membrane of islet beta cells and calculating the proportion of insulin vesicles through the observation of the ultrastructure of islet beta cells by transmission electron microscope, and detecting the phosphorylation level of Akt in the pancreatic PI3K/Akt signaling pathway by Western blotting. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: (1) At PIH 72, the rat FBG levels in SIA and SIB groups were normal and similar (P>0.05). Compared with the levels of those two groups, the rat FBG level in SA group was increased significantly (P<0.01), while the level in SB group showed no obvious change (P>0.05). Compared with that in SA group, the rat FBG level in SB group was decreased significantly (P<0.01). (2) At PIH 72, the morphology of rat islets was complete and the islet cells distributed regularly in SIA and SIB groups. Compared with those in SIA and SIB groups, the morphology of rat islets was incomplete, the insulin vesicles in islets were common, the islet cells distributed irregularly, and the cytoplasm of some islet beta cells was lightly stained or translucent in SA group; the morphology of islets in SB group did not change obviously. Compared with those in SA group, the morphology of islets was comparatively complete, the insulin vesicles in islets were less common, the islet cells distributed comparatively regularly, and the lightly stained or translucent cytoplasm of islet beta cells was less in SB group. (3) At PIH 72, the number of docked granules per 10 μm membrane of rat islet beta cells and the proportion of insulin vesicles in SIA and SIB groups were similar (P>0.05). Compared with those in SIA and SIB groups, the number of docked granules per 10 μm membrane of rat islet beta cells in SA group was decreased significantly (P<0.01), while the proportion of insulin vesicles was increased significantly (P<0.01); the number of docked granules per 10 μm membrane of rat islet beta cells in SB group was obviously decreased (P<0.05), while the proportion of insulin vesicles did not change obviously (P>0.05). Compared with those in SA group, the number of docked granules per 10 μm membrane of rat islet beta cells in SB group was significantly increased (P<0.01), while the proportion of insulin vesicles was significantly decreased (P<0.01). (4) At PIH 72, the phosphorylation levels of Akt in SIA, SIB, SA, and SB groups were 0.91±0.03, 0.98±0.03, 0.78±0.08, and 0.87±0.08, respectively. Compared with that in SIA group, the phosphorylation level of Akt was increased obviously in SIB group (P<0.05) but was decreased significantly in SA group (P<0.01), while the level in SB group did not change obviously (P>0.05). Compared with the level in SIB group, the phosphorylation levels of Akt in SA and SB groups were decreased significantly (P<0.01). Compared with that in SA group, the phosphorylation level of Akt in SB group was increased significantly (P<0.05). Conclusions: At the early stage post severe scald in rats, the activity of the pancreatic PI3K/Akt signaling pathway and the function of insulin secretion are reduced. Improving the activity of the pancreatic PI3K/Akt signaling pathway in rats can ameliorate the function of insulin secretion and recover the physiological level of blood glucose.

[Alternative donor HSCT for 109 children with acquired severe aplastic anemia: a single center retrospective analysis]

目的

了解替代供者（AD）移植一线治疗儿童再生障碍性贫血（AA）的疗效及安全性。

方法

回顾性分析2010年4月1日至2016年12月31日在上海儿童医学中心一线接受AD移植治疗的AA患儿临床资料，统计分析总生存（OS）率、植入成功率、移植物抗宿主病（GVHD）发生率等指标。

结果

共纳入109例患者，极重型AA（VSAA）32例，重型AA（SAA）64例，非重型AA（NSAA）伴输血依赖13例，中位年龄6（0.8~18）岁，其中44例患者接受全相合无关供者（MUD）移植，44例接受8–9/10位点不全相合无关供者（MMUD）移植，21例接受不全相合亲缘供者（MMRD）移植，所有患者均接受以外周血干细胞（PBSC）为主的移植，≥3个位点不合的单倍型移植加第三方脐血（UCB）一份。所有患者移植前均未接受过抗胸腺细胞球蛋白（ATG）治疗，并排除活动性感染。106例（97.2%）获造血重建，中性粒细胞中位重建时间为13（9~19）d，血小板中位重建时间为16（10~81）d。死亡13例，5年OS率为88.1%（95%CI 81.1%~91.4%），MUD、MMUD及MMRD三组患者OS率差异无统计学意义（P=0.361）。总体急性GVHD（aGVHD）及Ⅱ~Ⅳ度aGVHD发生率分别为74.3%和39.4%，总体慢性GVHD（cGVHD）和中度cGVHD发生率分别为30.7%和9.9%，无一例患者发生重度cGVHD。

结论

对于无同胞全相合供者的SAA/VSAA患儿，早期一线接受AD移植可能是一个选择，但需要进一步探索更有效的预防及治疗GVHD的措施。

A unique B cell epitope-based particulate vaccine shows effective suppression of hepatitis B surface antigen in mice

OBJECTIVE

This study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models.

METHODS

A series of peptides and carrier proteins were evaluated in HBV-tolerant mice to obtain an optimised therapeutic molecule. The immunogenicity, therapeutic efficacy and mechanism of the candidate were investigated systematically.

RESULTS

Among the HBsAg-aa119-125-containing peptides evaluated in this study, HBsAg-aa113-135 (SEQ13) exhibited the most striking therapeutic effects. A novel immunoenhanced virus-like particle carrier (CR-T3) derived from the roundleaf bat HBV core antigen (RBHBcAg) was created and used to display SEQ13, forming candidate molecule CR-T3-SEQ13. Multiple copies of SEQ13 displayed on the surface of this particulate antigen promote the induction of a potent anti-HBs antibody response in mice, rabbits and cynomolgus monkeys. Sera and purified polyclonal IgG from the immunised animals neutralised HBV infection in vitro and mediated efficient HBV/hepatitis B virus surface antigen (HBsAg) clearance in the mice. CR-T3-SEQ13-based vaccination induced long-term suppression of HBsAg and HBV DNA in HBV transgenic mice and eradicated the virus completely in hydrodynamic-based HBV carrier mice. The suppressive effects on HBsAg were strongly correlated with the anti-HBs level after vaccination, suggesting that the main mechanism of CR-T3-SEQ13 vaccination therapy was the induction of a SEQ13-specific antibody response that mediated HBV/HBsAg clearance.

CONCLUSIONS

The novel particulate protein CR-T3-SEQ13 suppressed HBsAg effectively through induction of a humoural immune response in HBV-tolerant mice. This B cell epitope-based therapeutic vaccine may provide a novel immunotherapeutic agent against chronic HBV infection in humans.

[A family of tumor necrosis factor receptor-associated periodic syndrome]

Objective: To analyze the clinical manifestations and gene variations of tumor necrosis factor receptor-associated periodic syndrome (TRAPS). Methods: Clinical data and gene testing of four children and three adult relatives in a family from Puning, Guangdong were retrospectively analyzed. CD4(+)T cells, CD8(+)T cells, B cells, monocytes and NK cells were assessed by flow cytometry. Plasma level of TNFR receptors were assessed by enzyme linked immunosorbent assay (ELISA). TNFRSF1A gene variation was identified by second generation sequencing. Swiss-Model was used to analyze the potential impact of TNFRSF1A gene variation on its protein tertiary structure. Results: For all the patients,periodic fever was the main clinical feature,combined with arthralgia,myalgia,multiple serositis,periorbital edema and migratory cutaneous rash,accompanied with elevated level of acute-phase reactants and increased white blood cell counts during each episode. This disease was found in both gender and every generation in this family. The median age of onset was 2 years, ranging from 6 months to 30 years. The plasma level of TNFR1 of the patients range from 0 to 12.4 ng/L,which was lower than that of the normal controls range from 18.0~22.2 ng/L,while the level of TNFR2 was normal. Also, the numbers of T cells, B cells and monocytes were within normal range; however,number of NK cells in the patients (0.070±0.034) was lower than that in the normal controls (0.152±0.122). The TNFRSF1A variation,located in exon 3: c.295T>A (p.C99S),was found in the proband as well as the other 6 family members,which could induce change of the side chain of amino acid according to the prediction of the three-dimensional structure,subsequently affecting the binding to the receptor. Conclusions: TRAPS is characterized by periodic fever,arthralgia,myalgia,multiple serositis,periorbital edema and migratory cutaneous rash,with a significant decrease in plasma level of TNFR1 and NK cells. The gene sequencing analysis revealed a pathogenic variation in TNFRSF1A gene.

[Genes and molecular mechanisms affecting the correlation between liver cancer and diabetes mellitus]

Hepatocellular carcinoma (HCC) is a common and high incidence disease in China. It is presently thought that diabetes is one of the independent risk factor for HCC. Diabetes and liver cancer are closely related, but the relationship and mechanism of diabetes and liver cancer are quite complex and controversial. Insulin resistance, glucose metabolism and lipid metabolism disorders, and abnormal release of inflammatory mediators are the common bases of these two diseases. The molecular mechanisms of glycogen synthase kinase-3, toll like receptor 4, CCL5, CXCL14 and NCOA5, TCF7L2 genes affecting the correlation between liver cancer and diabetes mellitus are discussed and explained to provide the basis for the study and treatment of disease.

Effect of pre-slaughter shackling and wing flapping on plasma parameters, postmortem metabolism, AMPK, and meat quality of broilers

The objective of this study was to determine the effects of shackling and wing flapping on stress, postmortem metabolism, AMP-activated protein kinase (AMPK), and quality of broiler pectoralis major. Before slaughter, a total of 80 Arbor Acres broilers was randomly categorized into 2 replicate pens (40 broilers per pen) and each pen randomly divided into 2 groups (shackling, T; control, C). Corticosterone, creatine kinase, and lactate dehydrogenase were determined on blood plasma parameters. Pectoralis major were removed after evisceration and used for determination of energy metabolism, meat quality, and AMPK phosphorylation. In this study, shackling and wing flapping increased (P < 0.05) plasma corticosterone level, creatine kinase activity, and lactate dehydrogenase activity. Shackling and wing flapping increased (P < 0.05) AMPKα(Thr172) and acetyl-CoA carboxylase (ACC) phosphorylation, followed by rapid glycolysis and accumulation of lactic acid, and leading to a fast pH decline in the initial postmortem meat. Shackling and wing flapping have an adverse effect on final meat quality, which increased (P < 0.05) muscle lightness, drip loss, and cooking loss. The results indicate that antemortem shackling and wing flapping increased stress and AMPKα(Thr172) phosphorylation, which may accelerate glycolysis and lead to a low water-holding capacity of broiler meat.

Experimental Evidence of Kinetic Effects in Indirect-Drive Inertial Confinement Fusion Hohlraums

We present the first experimental evidence supported by simulations of kinetic effects launched in the interpenetration layer between the laser-driven hohlraum plasma bubbles and the corona plasma of the compressed pellet at the Shenguang-III prototype laser facility. Solid plastic capsules were coated with carbon-deuterium layers; as the implosion neutron yield is quenched, DD fusion yield from the corona plasma provides a direct measure of the kinetic effects inside the hohlraum. An anomalous large energy spread of the DD neutron signal (∼282  keV) and anomalous scaling of the neutron yield with the thickness of the carbon-deuterium layers cannot be explained by the hydrodynamic mechanisms. Instead, these results can be attributed to kinetic shocks that arise in the hohlraum-wall-ablator interpenetration region, which result in efficient acceleration of the deuterons (∼28.8  J, 0.45% of the total input laser energy). These studies provide novel insight into the interactions and dynamics of a vacuum hohlraum and near-vacuum hohlraum.

Hippocampal overexpression of Down syndrome cell adhesion molecule in amyloid precursor protein transgenic mice

Down syndrome cell adhesion molecule (DSCAM) is located within the Down syndrome critical region of chromosome 21. DSCAM is a broadly expressed neurodevelopmental protein involved in synaptogenesis, neurite outgrowth, and axon guidance. We previously demonstrated DSCAM overexpression in the cortex of amyloid precursor protein (APP) transgenic mice, suggesting possible regulatory interactions between APP and DSCAM. APP mice exhibit deficits in hippocampus-dependent learning and memory. In this preliminary study, we examined age-related changes in DSCAM expression within the hippocampus in 16 APP transgenic mice (1, 3, 6 and 12 months old). Hippocampus-dependent spatial memory was assessed in APP mice and age-matched wild type littermates (WTs) using the Morris water maze (MWM). The cellular distribution of hippocampal DSCAM and total expression at both mRNA and protein levels were measured by immunohistochemistry, qRT-PCR, and western blotting, respectively. APP mice exhibited spatial memory deficits in the MWM. Intense DSCAM immunoreactivity was observed in the dentate gyrus granule cell layer and hippocampal stratum pyramidale. Total hippocampal DSCAM mRNA and protein expression levels were substantially higher in APP mice than WTs at 1 and 3 months of age. Expression decreased with age in both groups but remained higher in APP mice. DSCAM is overexpressed in the hippocampus over the first 12 months of life in APP mice, but especially during maturation to adulthood. In conclusion, these results suggest an association between DSCAM and APP mice, which is characterized by neuropathology and behavioral deficits. These results provide some clues for future studies on the role of DSCAM overexpression in the precocious cognitive decline observed in APP transgenic mice.

Effects of Contrast-Enhanced Ultrasonography in Monitoring Hepatic Microcirculation After Rat Liver Ischemia-Reperfusion Injury

OBJECTIVES

Our objective was to evaluate the effects of contrast-enhanced ultrasonography in monitoring microcirculation after rat liver ischemia-reperfusion injury.

MATERIALS AND METHODS

Male Wistar rats (n = 36) were divided into sham-operated and ischemia-reperfusion groups. Rats in the ischemia-reperfusion groups underwent normothermic liver ischemia for 15 minutes followed by 1, 6, or 24 hours of reperfusion. At different time points, contrast-enhanced ultrasonography was performed to determine peak intensity in monitoring hepatic microcirculation. In addition, serum levels of alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor α, and interleukin 1β levels were measured. Histopathologic changes were also observed.

RESULTS

One hour after reperfusion, peak intensity values decreased, and serum levels of alanine aminotransferase, tumor necrosis factor α, and interleukin 1β increased significantly in the ischemia-reperfusion group compared with the sham-operated group. Histology results showed mild injury. Six hours after reperfusion, peak intensity values decreased continuously, serum levels of alanine aminotransferase, tumor necrosis factor α, and interleukin 1β decreased, and aspartate aminotransferase levels increased. Histology results showed severe injury compared with 1 hour after reperfusion. Twenty-four hours after reperfusion, peak intensity values increased, alanine aminotransferase and aspartate aminotransferase levels decreased, and histology results showed moderate injury compared with 6 hours after reperfusion. Peak intensity values were negatively correlated to alanine aminotransferase (P < .05; γ = -0.38) and aspartate aminotransferase (P < .01; γ = -0.78) levels.

CONCLUSIONS

Microcirculation dysfunction after liver ischemia-reperfusion injury can be monitored by contrast-enhanced ultrasonography. The perfusion of contrast agents negatively correlates to the severity of injuries.

Association between IL2/IL21 and SH2B3 polymorphisms and risk of celiac disease: a meta-analysis

Celiac disease (CD) is a common autoimmune disorder characterized by heightened immunological response to ingested gluten. Certain gene polymorphisms of IL2/IL21 (rs6822844 and rs6840978) and SH2B3 (rs3184504) may influence susceptibility to CD, although the effects remain unclear. We performed a meta-analysis of the associations between rs6822844, rs6840978, and rs3184504 polymorphisms and CD risk. PubMed, EMBASE, and the China National Knowledge Infrastructure were searched. ORs and 95%CIs of each single nucleotide polymorphism (SNP) were estimated using the fixed-effect model if I(2) < 50% in the test of heterogeneity; otherwise, the random-effect model was used. Our meta-analysis included 12,986 CD cases and 28,733 controls from 16 independent samples, and the analysis of each SNP contained a subset of the total. We found that the minor allele T of both rs6822844 (T vs G, OR = 0.72, 95%CI = 0.67-0.78, P < 0.001) and rs6840978 (T vs C, OR = 0.76, 95%CI = 0.71-0.83, P < 0.001) in IL2/IL21 significantly decreased the risk of CD. However, the minor allele A of rs3184504 (A vs G, OR = 1.18, 95%CI = 1.12-1.24, P < 0.001) in SH2B3 significantly increased CD susceptibility. The estimated lambda values were 0.49, 0.50, and 0.53 for rs6822844, rs6840978, and rs3184504, respectively, suggesting that a co-dominant model of genotype effect was most appropriate for the three SNPs. Our results support associations between the three SNPs and CD and provide a strong argument for further research.

Association of TLR2 and TLR4 non-missense single nucleotide polymorphisms with type 2 diabetes risk in a southern Chinese population: a case-control study

Toll-like receptors (TLRs), the triggers of the innate and adaptive immune responses, are involved in the pathogenesis of type 2 diabetes mellitus (T2DM). Several studies have investigated the effects of genetic polymorphisms in TLR4 and TLR2, but they have yielded limited results. We investigated whether non-missense genetic polymorphisms in the regulatory regions of TLR4 and TLR2 were related to T2DM in a southern Chinese population. Single nucleotide polymorphisms (SNPs) in TLR4 (rs1927911, rs11536889, rs1927907, rs1927906, rs1927914, rs7873784, and rs2149356) and TLR2 (rs1898830, rs3804099, rs4696480, and rs3804100) were genotyped in 552 T2DM and 552 unrelated age- and gender-matched controls by SNaPShot Multiplex assay. Genotypes GG (OR = 0.09, 95%CI = 0.01- 0.83, P = 0.03) and CG (OR = 0.08, 95%CI = 0.01-0.74, P = 0.03) of the 3'-untranslated region (UTR) SNP rs7873784 in TLR4, and genotype AG (OR = 0.67, 95%CI = 0.46-0.97, P = 0.04) and allele G (OR = 0.88, 95%CI = 0.79-0.97, P = 0.01) of the intron SNP rs1898830 in TLR2 were identified as protective against the development of T2DM in southern Chinese people. In contrast, a meta-analysis of rs1927911 and rs1927914 showed no association. Haplotypes AGTT (OR = 0.34, 95%CI = 0.15-0.77, P = 0.01) and AATT (OR = 1.20, 95%CI = 1.01- 1.44, P = 0.05) in TLR2 were significantly associated with susceptibility to T2DM. Our results suggest that the effects of non-missense polymorphisms located in the regulatory regions of TLR4 and TLR2 should not be neglected in T2DM association analysis.

Esophageal leiomyosarcoma: clinical analysis and surgical treatment of 12 cases

Leiomyosarcoma of the esophagus is a rare malignant tumor with slow growth and late metastasis. The aim of this study was to reassess the clinical characteristics and treatment modality in one of the largest series of esophageal leiomyosarcomas from a single institution. From February 1973 to December 2011, 12 cases of esophageal leiomyosarcoma were identified. The principal symptoms included progressive dysphagia in 11 cases (91.7%), retrosternal/back pain in four (33.3%), weight loss in four (33.3%), upper gastrointestinal hemorrhage in two (16.7%), and emesis in two (16.7%). The average duration of symptoms was 10.6 months. The location of the primary tumor was in the middle thoracic esophagus in five cases, and lower thoracic esophagus in seven cases. Six cases were classified as the polypoid type, five cases as the infiltrative type, and only one case as the intramural type. All 12 of the patients underwent esophagectomies, and radical resections were achieved in these patients. Based on the Kaplan-Meier Method, the 3-, 5-, and 10-year survival rates were 80.0%, 58.3%, and 31.1%, respectively, with a median survival of 63 months. Five-year survival rates for patients with polypoid or intramural tumors (n = 7) was 83.3%, and for patients with infiltrative tumor (n = 5) it was 25.0%. One of the patients had tumor resected four times and survived for 161 months. In conclusion, patients presenting with esophageal leiomyosarcomas have an excellent prognosis, and radical resection may achieve acceptable results.

Fragmentation mechanisms for methane induced by 55 eV, 75 eV, and 100 eV electron impact

The fragmentation of CH4 (2+) dications following 55 eV, 75 eV, and 100 eV electron impact double ionization of methane was studied using a cold target recoil-ion momentum spectroscopy. From the measured momentum of each recoil ion, the momentum of the neutral particles has been deduced and the kinetic energy release distribution for the different fragmentation channels has been obtained. The doubly charged molecular ions break up into three or more fragments in one or two-step processes, resulting in different signatures in the data. We observed the fragmentation of CH4 (2+) dications through different mechanisms according to the momentum of the neutral particles. For example, our result shows that there are three reaction channels to form CH2 (+), H(+), and H, one synchronous concerted reaction channel and two two-step reaction channels. For even more complicated fragmentation processes of CH4 (2+) dications, the fragmentation mechanism can still be identified in the present measurements. The slopes of the peak in the ion-ion coincidence spectra were also estimated here, as they are also related to the fragmentation mechanism.

Living status in patients over 85 years of age after TUVRP

INTRODUCTION

To evaluate surgical risk and post-operative quality of living status in patients over 85 years of age after transurethral vaporization resection of the prostate (TUVRP).

METHODS

Sixty patients over 85 years of age underwent TUVRP were compared with 228 patients less than the age of 80 years. Group A was 60 patients greater than 85 years of age, Group B was 137 patients from 71 to 79 years of age, and Group C was 91 patients from 60 to 70 years of age.

RESULTS

In Group A, pre-operative ASA grade was higher than the other two groups, compared with Group C, p < 0.01. Operating time was 40.03 ± 18.90 min, compared in the three groups, p > 0.05. Follow-up was obtained in 49 (81.67%) patients; of them 10 patients were deaths with a survival time of 22.90 ± 11.14 months. In the 39 survivors, post-operative IPSS score was 11.17 ± 6.9, compared with Group B, p > 0.05 and Group C, p < 0.01. Quality of Life (QOL) index was 1.11 ± 0.80, compared with Group B, p < 0.001 and Group C, p < 0.01. Barthel Index score in 16 patients was >60 and the score was 82.81 ± 8.56 pre-operatively. The patients with >60 were increased to 19 cases and the score was improved to 90.93 ± 7.58 (p < 0.001) in follow-up.

CONCLUSION

Surgical risk in patients over 85 years of age was higher than patients less than the age of 80 years. A safety TUVRP could improve their voiding function and activities of daily living.

Epcam, CD44, and CD49f distinguish sphere-forming human prostate basal cells from a subpopulation with predominant tubule initiation capability

BACKGROUND

Human prostate basal cells expressing alpha-6 integrin (CD49f(Hi)) and/or CD44 form prostaspheres in vitro. This functional trait is often correlated with stem/progenitor (S/P) activity, including the ability to self-renew and induce differentiated tubules in vivo. Antigenic profiles that distinguish tubule-initiating prostate stem cells (SCs) from progenitor cells (PCs) and mature luminal cells (LCs) with less regenerative potential are unknown.

METHODOLOGY/PRINCIPLE FINDINGS

Prostasphere assays and RT-PCR analysis was performed following FACS separation of total benign prostate cells based upon combinations of Epcam, CD44, and/or CD49f expression. Epithelial cell fractions were isolated, including Epcam(+)CD44(+) and Epcam+CD44+CD49f(Hi) basal cells that formed abundant spheres. When non-sphere-forming Epcam(+)CD44(-) cells were fractionated based upon CD49f expression, a distinct subpopulation (Epcam(+)CD44(-)CD49f(Hi)) was identified that possessed a basal profile similar to Epcam(+)CD44(+)CD49f(Hi) sphere-forming cells (p63(+)AR(Lo)PSA(-)). Evaluation of tubule induction capability of fractionated cells was performed, in vivo, via a fully humanized prostate tissue regeneration assay. Non-sphere-forming Epcam(+)CD44(-) cells induced significantly more prostate tubular structures than Epcam(+)CD44(+) sphere-forming cells. Further fractionation based upon CD49f co-expression identified Epcam(+)CD44(-)CD49f(Hi) (non-sphere-forming) basal cells with significantly increased tubule induction activity compared to Epcam(+)CD44(-)CD49f(Lo) (true) luminal cells.

CONCLUSIONS/SIGNIFICANCE

Our data delineates antigenic profiles that functionally distinguish human prostate epithelial subpopulations, including putative SCs that display superior tubule initiation capability and induce differentiated ductal/acini structures, sphere-forming PCs with relatively decreased tubule initiation activity, and terminally differentiated LCs that lack both sphere-forming and tubule-initiation activity. The results clearly demonstrate that sphere-forming ability is not predictive of tubule-initiation activity. The subpopulations identified are of interest because they may play distinct roles as cells of origin in the development of prostatic diseases, including cancer.

Tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Evidence that miRNAs are different from other RNAs

An examination of 513 known pre-miRNAs and 237 other RNAs (tRNA, rRNA, and mRNA) revealed that miRNAs were significantly different from other RNAs (p < 0.001). miRNA genes were less conserved than other RNA genes, although their mature miRNA sequences were highly conserved. The A+U content of pre-miRNAs was higher than non-coding RNA (p < 0.001), but lower than mRNAs. The nucleotides in pre-miRNAs formed more hydrogen bonds and base pairs than in other RNAs. miRNAs had higher negative adjusted minimal folding free energies than other RNAs except tRNAs (p < 0.001). The MFE index (MFEI) was a sufficient criterion to distinguish miRNAs from all coding and non-coding RNAs (p < 0.001). The MFEI for miRNAs was 0.97, significantly higher than tRNAs (0.64), rRNAs (0.59), or mRNAs (0.65). Our findings should facilitate the prediction and identification of new miRNAs using computational and experimental strategies.

Adsorptive separation of hemoglobin by molecularly imprinted chitosan beads

A simply hemoglobin (Hb) molecularly imprinted polymer (MIP) was prepared using Hb as the imprinted molecule, acrylamide as the functional monomer and cross-linked chitosan beads as the supporting matrix. The MIP was achieved by entrapment of the selective soft polyacrylamide gel in the pores of the cross-linked chitosan beads by letting acrylamide monomer and the protein diffuse into the pores of chitosan beads before starting the polymerization. The chitosan beads were freed from the surrounding polyacrylamide gel by washing. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. Langmuir analysis showed that an equal class of adsorption was formed in the MIP and the adsorption equilibrium constant and the maximum adsorption capacity were evaluated. The MIP has much higher adsorption capacity for Hb than the non-imprinted polymer with the same chemical composition, and the MIP also has a higher selectivity for the imprinted molecule. The MIP can be reused in an easy way and the reproduction coefficient was approximately 100% at low concentration.

Chitinolytic activities in Bacillus thuringiensis and their synergistic effects on larvicidal activity

AIMS

To investigate the distribution of chitinase in Bacillus thuringiensis strains, and the enhancing effects of the chitinase-producing B. thuringiensis strains on insecticidal toxicity of active B. thuringiensis strain against Spodoptera exigua larvae.

METHODS AND RESULTS

The chitinolytic activities of B.thuringiensis strains representing the 70 serotypes were investigated by the whitish opaque halo and the colorimetric method. Thirty-eight strains produced different levels of chitinase at pH 7.0, and so did 17 strains at pH 10.0. The strain T04A001 exhibited the highest production, reaching a specific activity of 355 U ml(-1) in liquid medium. SDS-PAGE and Western blotting showed that the chitinase produced by some B. thuringiensis strains had a molecular weight of about 61 kDa. The bioassay results indicated that the chitinase-producing B. thuringiensis strains could enhance the insecticidal activity of B. thuringiensis strain DL5789 against S. exigua larvae, with an enhancing ratio of 2.35-fold.

CONCLUSION

This study demonstrated that chitinase was widely produced in B. thuringiensis strains and some of the strains could enhance the toxicity of active B. thuringiensis strain.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first investigation devoted exclusively to analyse the distribution of chitinase in B. thuringiensis. It infers that the chitinase produced by B. thuringiensis might play a role in the activity of the biopesticide.

Serum- and glucocorticoid-inducible kinase SGK phosphorylates and negatively regulates B-Raf

Phosphorylation can both positively and negatively regulate activity of the Raf kinases. Akt has been shown to phosphorylate and inhibit C-Raf activity. We have recently reported that Akt negatively regulates B-Raf kinase activation by phosphorylating multiple residues within its amino-terminal regulatory domain. Here we investigated the regulation of B-Raf by serum and glucocorticoid-inducible kinase, SGK, which shares close sequence identity with the catalytic domain of Akt but lacks the pleckstrin homology domain. We observed that SGK inhibits B-Raf activity. A comparison of substrate specificity between SGK and Akt indicates that SGK is a potent negative regulator of B-Raf. In contrast to Akt, SGK negatively regulates B-Raf kinase activity by phosphorylating only a single Akt consensus site, Ser(364). Under similar experimental conditions, SGK displays a measurably stronger inhibitory effect on B-Raf kinase activity than Akt, whereas Akt exhibits a more inhibitory effect on the forkhead transcription factor, FKHR. The selective substrate specificity is correlated with an enhanced association between Akt or SGK and their preferred substrates, FKHR and B-Raf, respectively. These results indicate that B-Raf kinase activity is negatively regulated by Akt and SGK, suggesting that the cross-talk between the B-Raf and other signaling pathways can be mediated by both Akt and SGK.

Molecular mechanisms by which iron induces nitric oxide synthesis in cultured proximal tubule cells

Nitric oxide (NO) levels are increased after exposure of cultured proximal tubule cells (PTC) to non-haem iron, potentially contributing to PTC injury in disease states associated with increased iron exposure, including proteinuric renal disease. The mechanisms underlying this observed increase were investigated. After 3 h exposure to 400 microM nitrilotriacetate (NTA)-Fe, inducible nitric oxide synthase (iNOS) mRNA expression was significantly increased, with a corresponding increase in iNOS protein after 12 h. The nuclear binding activity of NFkappaB with 400 microM NTA-Fe was increased, and pyrrolidine dithiocarbamate (PDTC), an antioxidant inhibitor of NFkappaB, prevented both activation of NFkappaB and NO production in response to NTA-Fe. Inhibition of protein tyrosine kinase reduced iNOS mRNA, iNOS protein levels and NO production in response to NTA-Fe. The effect of tyrosine kinase inhibition on NFkappaB activation was variable, with herbimycin but not genistein having an inhibitory effect. Activation of either protein kinase A or C increased iNOS mRNA and protein levels, and NO production in response to NTA-Fe, whereas only the protein kinase C activator phorbol dibutyrate (PDBu) had a stimulatory effect on NFkappaB activation. The protein kinase A activator forskolin did not alter iron-induced activation of NFkappaB. These data suggest that the observed increase in NO production by PTC in response to iron is due to increased transcription of iNOS. The transcriptional regulation of this response is complex and involves NFkappaB, protein tyrosine kinase and the protein kinases A and C.

Specific involvement of G(alphai2) with epidermal growth factor receptor signaling in rat hepatocytes, and the inhibitory effect of chronic ethanol

We have previously shown that chronic alcohol consumption inhibits liver regeneration by impairing epidermal growth factor receptor (EGFR)-operated phospholipase C-(gamma1) (PLC-(gamma1)) activation and the resultant rise in intracellular [Ca(2+)](i). In hepatocytes, activation of PLC-(gamma1) by EGFR requires involvement of a pertussis toxin-sensitive inhibitory guanine nucleotide-binding regulatory protein (G(alphai)) as an intermediate. In the present study, we first identified the G(alphai) protein isoform associated with the activated EGFR, and then examined whether the toxic effect of alcohol on EGFR signaling and liver cell proliferation was exerted on this association. In cultured hepatocytes from control rats, EGF rapidly induced association between EGFR and G(alphai2) but not other G(alphai) isoforms. In hepatocytes from rats fed alcohol for 16 weeks, EGF failed to stimulate this association of G(alphai2) with the EGFR. The impairment of EGFR-G(alphai2) complex formation caused by alcohol was associated with a decreased level of G(alphai2) in the plasma membrane fraction (approximately 50% control). Pertussis toxin, an inhibitor of G(alphai) function, produced an analogous disruption of the association between G(alphai2) and the EGFR, as well as inhibiting EGF-induced DNA synthesis. It is concluded that, in hepatocytes, G(alphai2) is specific among G(alphai) isoforms in coupling activation of the EGFR to other signaling pathways that control cell proliferation. Impaired coupling of G(alphai2) of EGFR could contribute to the mechanism by which chronic alcohol exposure inhibits liver regeneration.

Regulation of the Raf kinase by phosphorylation

The Raf serine/threonine kinase plays an essential role to relay intracellular signals from the protooncogene Ras to activation of the mitogen-activated protein kinase (MAPK) cascade. The Raf kinase family consists of C-Raf (Raf-1), B-Raf, and A-Raf. Extensive efforts have been made in the last decade to study Raf regulation; however, precise molecular mechanism for Raf activation is still not fully understood. In this report, we discuss the current model of Raf regulation. Here we also report our recent findings that phosphorylation of Thr598 and Ser601, which lie between kinase subdomains VII and VIII, is essential for B-Raf activation by Ras. Substitution of these residues to alanine (B-RafAA) abolished Ras-induced B-Raf activation, without altering the association of B-Raf with other signaling proteins. Phosphopeptide mapping and immunoblotting with phosphospecific antibodies, which selectively recognize Thr598 and Ser601, phosphorylated B-Raf, confirmed that Thr598 and Ser601 are in vivo phosphorylation sites induced by Ras. Further, replacement of these two sites with acidic residues (B-RafED) renders B-Raf constitutively active. Consistent with these data, B-RafAA and B-RafED exhibited diminished and enhanced ability, respectively, to stimulate extracellular signal-regulated kinase (ERK) and Elk-dependent transcription. Moreover, functional studies revealed that B-RafED was able to promote NIH3T3 cell transformation and PC12 cell differentiation. Because Thr598 and Ser601 are conserved in all Raf family members, from Caenorhabditis elegans to mammals, we propose that phosphorylation of these two residues may be a general mechanism for Raf activation.

Activation of B-Raf kinase requires phosphorylation of the conserved residues Thr598 and Ser601

The Raf kinase family serves as a central intermediate to relay signals from Ras to ERK. The precise molecular mechanism for Raf activation is still not fully understood. Here we report that phosphorylation of Thr598 and Ser601, which lie between kinase subdomains VII and VIII, is essential for B-Raf activation by Ras. Substitution of these residues by alanine (B-RafAA) abolished Ras-induced B-Raf activation without altering the association of B-Raf with other signaling proteins. Phosphopeptide mapping and immunoblotting with phospho-specific antibodies confirmed that Thr598 and Ser601 are in vivo phosphorylation sites induced by Ras. Furthermore, replacement of these two sites by acidic residues (B-RafED) renders B-Raf constitutively active. Con sistent with these data, B-RafAA and B-RafED exhibited diminished and enhanced ability, respectively, to stimulate ERK activation and Elk-dependent transcription. Moreover, functional studies revealed that B-RafED was able to promote NIH 3T3 cell transformation and PC12 cell differentiation. Since Thr598 and Ser601 are conserved in all Raf family members from Caenorhabditis elegans to mammals, we propose that phosphorylation of these two residues may be a general mechanism for Raf activation.

Protection of regenerating liver after partial hepatectomy from carbon tetrachloride hepatotoxicity in rats: role of hepatic stimulator substance

BACKGROUND

In the present study, we examined the effect of hepatic stimulator substance (HSS) on modulating hepatotoxicity induced by carbon tetrachloride (CCl4) in the regenerating rat liver.

METHODS

Hepatotoxicity was induced in vivo by administering CCl4 to rats that had undergone a 68% partial hepatectomy (PH). In vitro studies were also performed in hepatocytes isolated from PH rats.

RESULTS

Hepatic stimulator substance was extracted from regenerating rat liver 96 h after PH and its activity, as determined according to the method of LaBrecque, reached its maximum 96 h after PH. At this time, the mortality induced by CCl4 was significantly decreased in PH rats compared with sham-operated rats (18 vs 59%, P < 0.01). Likewise, changes in serum alanine aminotransferase (ALT) or bilirubin induced by CCl4 were less in rats after 96 h PH. The resistance of regenerating hepatocytes to CCl4 was retained in in vitro samples. Thus, leakage of intracellular ALT or aspartate aminotransferase induced by CCl4 in hepatocytes from 96 h hepatectomised rats was less than in control hepatocytes. HSS demonstrated a protective effect on hepatocytes against CCl4 both in vivo and in vitro. In additional studies, regenerating liver showed increased mitochondrial respiratory activity and enhanced plasma membrane fluidity. The HSS was also shown to increase hepatic mitochondrial respiratory activity and enhance plasma membrane fluidity. Further, the protective effect induced by HSS was correlated with the restoration of mitochondrial respiratory activity and plasma membrane fluidity induced by CCl4.

CONCLUSIONS

Regenerating rat liver exhibits resistance to CCl4-induced hepatotoxicity, and the protection afforded by the regenerating state can be attributed, at least in part, to HSS-induced increases in mitochondrial respiratory activity and plasma membrane fluidity.

Chronic ethanol consumption disrupts complexation between EGF receptor and phospholipase C-gamma1: relevance to impaired hepatocyte proliferation

We have previously shown that chronic ethanol consumption inhibits liver regeneration by impairing EGF receptor (EGFR)-operated phospholipase C-gamma1 (PLC-gamma1) activation and resultant intracellular Ca2+ signalling. Activation of PLC-gamma1 by EGFR requires the EGFR to bind to PLC-gamma1 after its translocation from cytosol to cytoskeleton. In order to understand the mechanism by which ethanol impairs PLC-gamma1 activation, we examined the effect of alcohol on interactions between EGFR and PLC-gamma1. In cultured hepatocytes from control rats, EGF rapidly induced tyrosine phosphorylation of both the EGFR and of PLC-gamma1. EGF also stimulated PLC-gamma1 translocation from cytosol to a cytoskeletal compartment where PLC-gamma1 interacted with EGFR. In hepatocytes from rats fed ethanol for 16 weeks, the above reactions were substantially inhibited. Tyrphostin AG1478, an EGFR-specific tyrosine kinase inhibitor, mimicked the effects of chronic ethanol on EGFR phosphorylation, PLC-gamma1 translocation and interactions between EGFR and PLC-gamma1 in the cytoskeleton. Further, tyrphostin AG1478 also inhibited EGF-induced DNA synthesis. These results indicate that ethanol impairs EGFR-operated [Ca2+]i signaling by disrupting the interactions between EGFR and PLC-gamma1.

Does steatohepatitis impair liver regeneration? A study in a dietary model of non-alcoholic steatohepatitis in rats

BACKGROUND

Impaired liver regeneration is a feature of alcoholic hepatitis, but the relative importance of alcohol, nutritional imbalance and inflammatory mediators in causing this effect is unclear. Non-alcoholic steatohepatitis (NASH) is a form of liver disease with similar morphology to alcoholic hepatitis, but the effect of this disorder on liver regeneration is unclear. We, therefore, examined the status of liver regeneration in a rat nutritional model of hepatic steatosis with inflammation, which is morphologically identical to NASH in humans.

METHODS

Male Wistar rats received a methionine-choline-deficient diet (MCDD) for 4 weeks before experiments and both isocaloric pair-fed and ad libitum-fed rats were used as controls. Following partial hepatectomy (68%), the extent of hepatic regeneration was determined 24 h later using [3H]-thymidine incorporation and restitution of liver mass.

RESULTS

There was no significant difference of [3H]-thymidine incorporation in MCDD-fed, pair-fed and ad libitum-fed rats (80+/-27, 78+/-11 and 80+/-6.3 d.p.m./microg DNA, respectively). Similarly, restituted liver masses in three groups of rats were not significantly different (17+/-3.8, 18+/-1.8 and 17+/-3.1% initial liver weight, respectively).

CONCLUSIONS

The similarities in hepatic histology and cytochrome P450 2E1 induction between this nutritional model of hepatic steatohepatitis and alcoholic steatohepatitis imply that these two disorders share pathogenetic mechanisms. However, liver regeneration is not altered by NASH in rats, indicating that the nutritional and inflammatory changes that appear similar to those of alcoholic liver disease do not cause impairment of liver regeneration.

Evidence suggesting that nitric oxide mediates iron-induced toxicity in cultured proximal tubule cells

The potential role of nitric oxide (NO) in iron-induced toxicity was studied in proximal tubule cells in primary culture. NO production (NO2-/NO3-) was significantly increased in iron-treated compared with control cells (3.43 +/- 0.08 vs. 1.56 +/- 0.08 nmol/dish, P < 0.01). NO synthase (NOS) activity was also induced by iron treatment (16.2 +/- 2.0 vs. 0.4 +/- 0.2 nmol of [3H]citrulline/mg protein, P < 0.01). L-Arginine, a substrate for NOS, augmented iron-induced NO production and cell damage [lactate dehydrogenase (LDH) leakage], whereas aminoguanidine, an inhibitor of NOS, reduced iron-induced NO production and LDH leakage. Sodium nitroprusside, an exogenous NO donor, induced LDH leakage in a dose-dependent manner, but no effect on lipid peroxidation (malo-ndialdehyde bis[dimethyl acetal] (MDA) production) was observed. Superoxide dismutase and catalase decreased iron-induced MDA production but did not affect LDH leakage or NO production. Dimethylpyrroline N-oxide and desferal prevented MDA production, LDH leakage, and NO production. We concluded that NO is one of the mediators of iron-induced toxicity in proximal tubule cells. NO-induced toxicity is not dependent on lipid peroxidation. This may explain the variable effect of different antioxidants on cell damage and lipid peroxidation in iron-induced cytotoxicity.

Ethanol perturbs receptor-operated cytosolic free calcium concentration signals in cultured rat hepatocytes

BACKGROUND & AIMS

Studies of the acute effects of ethanol on hepatocellular free calcium concentration, [Ca2+]i, and on receptor-operated [Ca2+]i signals have produced conflicting results. The effects of ethanol on basal and receptor-operated [Ca2+]i signals in rat hepatocytes cultured on two different extracellular matrices were examined.

METHODS

[Ca2+]i was determined by digitized fluorescence microscopy and inositol 1,4,5-trisphosphate (Ins[1,4,5]P3) by high-performance liquid chromatography (HPLC).

RESULTS

Ethanol induced an increase in [Ca2+]i in hepatocytes cultured on collagen I but not on the more physiological substratum, matrigel. Compared with hepatocytes cultured on matrigel, cells on collagen I exerted less responsiveness and lower amplitude of [Ca2+]i signals to vasopressin or phenylephrine. The effects of ethanol on receptor-operated [Ca2+]i signals were examined in hepatocytes cultured on matrigel. Incubation of hepatocytes with physiologically attainable concentrations of ethanol (20-30 mmol/L) for 30 minutes to 48 hours perturbed epidermal growth factor, phenylephrine, and lower concentration (< or = 1 nmol/L) of vasopressin-induced [Ca2+]i signaling by reducing the amplitude and changing the pattern of [Ca2+]i signals. Alcohol induced-impairment of [Ca2+]i signaling was associated with decreased production of Ins(1,4,5)P3.

CONCLUSIONS

Alcohol does not itself evoke an increase in [Ca2+]i in hepatocytes cultured on matrigel but perturbs receptor-operated [Ca2+]i signaling. This is associated with and could be caused by impaired generation of Ins(1,4,5)P3.

Chronic ethanol administration to rats decreases receptor-operated mobilization of intracellular ionic calcium in cultured hepatocytes and inhibits 1,4,5-inositol trisphosphate production: relevance to impaired liver regeneration

We tested the hypothesis that ethanol impairs liver regeneration by abrogating receptor-mediated elevation of cytosolic free calcium ([Ca2+]i). In rats fed for 16 weeks with ethanol, hepatocellular proliferation induced by partial hepatectomy was greatly impaired. Similarly, EGF-induced DNA synthesis was reduced in cultured hepatocytes from ethanol-fed rats. There was no change in the number or affinity of EGF receptors on hepatocytes from ethanol-fed rats. Despite this, EGF-mediated production of inositol 1,4,5-trisphosphate (Ins[1,4,5]P3) was lower in hepatocytes from ethanol-fed rats, and the EGF-induced [Ca2+]i transient appeared to be abrogated. When vasopressin or phenylephrine were used as cell surface receptor ligands, hepatocytes cultured from ethanol-fed rats exhibited major reductions in Ins(1,4,5)P3 synthesis. This was associated with greatly truncated [Ca2+]i transients. These changes were not due to an effect on the Ins(1,4,5)P3 receptor on the endoplasmic reticulum or to a decrease in the size of the Ins(1,4,5)P3-mobilizable intracellular Ca+2 store. Further, mobilization of the same Ca2+ store by 2,5-di-tert-butylhydroquinone or thapsigargin restored the ability of hepatocytes from ethanol-fed rats to proliferate when exposed to EGF. It is concluded that chronic ethanol consumption inhibits liver regeneration by a mechanism that is, at least partly, the result of impaired receptor-operated [Ca2+]i signaling due to reduced generation of Ins(1,4,5)P3.