[Construction and validation of a nomogram model of early related factors for hepatic insufficiency after hemihepatectomy]

Objectives: To investigate the early related factors for hepatic insufficiency after hemihepatectomy and to construct and validate a nomogram model. Methods: This was a retrospective cohort study.There were 207 patients with liver tumor who underwent hemihepatectomy in the Department of Hepatobiliary Surgery,Cancer Hospital,Chinese Academy of Medical Sciences from October 2016 to December 2022. Using the random number method,patients were randomly divided into a model group(n=166) and a validation group(n=41) according to an 4︰1 ratio. There were 118 males and 48 females in the modeling group,with an age (M(IQR)) of 59.0(13.3) years (range: 22.0 to 81.0 years),42 patients in the group with postoperative liver insufficiency and 124 patients in the group without postoperative liver insufficiency. There were 32 males and 9 females in the validation group, with an age of 54.0(19.0) years (rang: 25.0~81.0 years). The first results of the peripheral blood test of patients within 24 hours after surgery were collected,and the independent related factors for incomplete postoperative liver function were determined by multivariate Logistic regression analysis,and related factors of postoperative incomplete liver function were screened by best subset selection. A nomogram model of the risk of postoperative hepatic insufficiency after hemihepatectomy was constructed using R software,followed by internal and external validation of the model. Results: Multivariate logistic regression analysis showed that elevated D-dimer level and decreased antithrombin Ⅲ (AT-Ⅲ) activity within 24 hours after surgery were independent related factors for the development of postoperative hepatic insufficiency in hemihepatectomized patients. The results of the best subset selection showed that ALT,D-dimer, and AT-Ⅲ activity levels within 24 hours postoperatively were the most relevant factors for postoperative hepatic insufficiency. The R software was applied to build a nomogram prediction model based on the above three indicators in the model set,and the receiver operating characteristic(ROC) curve of the model showed an area under the curve of 0.803 and the calibration curve showed a U-index of -0.012 for the model(P=0.977). The results of the clinical decision analysis and the clinical impact curve indicated that the model had good clinical utility. The internal validation results of the Bootstrap method suggested that the model had reasonable consistency. The area under the ROC curve of the validation group model was 0.806,suggesting that the model had a good generalization prediction ability. Conclusions: The levels of ALT,D-dimer,and AT-Ⅲ activity within 24 hours after hemihepatectomy are valuable indicators for predicting liver insufficiency after hemihepatectomy. The nomogram model is reliable and can be used as an indicator for close postoperative monitoring.

[Management and short-term outcomes of neonates born to mothers infected with SARS-CoV-2 Omicron variant]

Objective: To summarize the management and short-term outcomes of neonates delivered by mothers infected with SARS-CoV-2 Omicron variant. Methods: A retrospective study was performed on 158 neonates born to mothers infected with SARS-CoV-2 Omicron variant admitted to the isolation ward of Children's Hospital of Fudan University from March 15^th, 2022 to May 30^th, 2022. The postnatal infection control measures for these neonates, and their clinical characteristics and short-term outcomes were analyzed. They were divided into maternal symptomatic group and maternal asymptomatic group according to whether their mothers had SARS-CoV-2 symptoms. The clinical outcomes were compared between the 2 groups using Rank sum test and Chi-square test. Results: All neonates were under strict infection control measures at birth and after birth. Of the 158 neonates, 75 (47.5%) were male. The gestational age was (38⁺³±1⁺³) weeks and the birth weight was (3 201±463)g. Of the neonates included, ten were preterm (6.3%) and the minimum gestational age was 30⁺¹ weeks. Six neonates (3.8%) had respiratory difficulty and 4 of them were premature and required mechanical ventilation. All 158 neonates were tested negative for SARS-COV-2 nucleic acid by daily nasal swabs for the first 7 days. A total of 156 mothers (2 cases of twin pregnancy) infected with SARS-CoV-2 Omicron variant, the time from confirmed SARS-CoV-2 infection to delivery was 7 (3, 12) days. Among them, 88 cases (56.4%) showed clinical symptoms, but none needed intensive care treatment. The peripheral white blood cell count of the neonates in maternal symptomatic group was significantly higher than that in maternal symptomatic group (23.0 (18.7, 28.0) × 10⁹ vs. 19.6 (15.4, 36.6) × 10⁹/L, Z=2.44, P<0.05). Conclusions: Neonates of mothers infected with SARS-CoV-2 Omicron variant during third trimester have benign short-term outcomes, without intrauterine infection through vertical transmission. Strict infection control measures at birth and after birth can effectively protect these neonates from SARS-CoV-2 infection.

[Recommendations for the diagnosis and treatment of connective tissue disease-associated interstitial lung disease in China]

Interstitial lung disease (ILD) is a frequent complication of patients with connective tissue disease (CTD) and significantly affects morbidity and mortality. Disease course may vary from stable or mildly progressive to more severe, with rapid loss of lung function. At present, there are great challenges and poor prognosis in the diagnosis and treatment of CTD-ILD. Based on the evidence and guidelines from China and other countries, experts from the Chinese Rheumatology Association developed standardization of diagnosis and treatment of CTD-ILD. The aim is to strengthen the early identification of, standardize the diagnosis and treatment of CTD-ILD, and delay the progress of the disease.

[Recommendations of diagnosis and treatment of gout in China]

Gout is a crystal associated arthritis caused by monosodium urate (MSU) accumulating in joint, and it belongs to metabolic rheumatic disease. In China, gout is common but it is insufficient for education of standardized diagnosis and treatment for gout. Based on the evidence and guidelines from China and other countries, Chinese gout Collaborative Research Group developed standardization of diagnosis and treatment of gout in China. The purpose is to standardize the methods for diagnosis of gout, treatment opportunity and strategies in order to reduce misdiagnosis, missed diagnosis and irreversible damage.

P4528Feasibility and safety of left bundle branch area pacing by transvenous approach through the interventricular septum in patients with left bundle branch block

Background

His bundle pacing (HBP) has been shown to correct left bundle branch block (LBBB), however it often requires high pacing output and the success rate is variable.

Objective

To assess the feasibility and safety of left bundle branch area pacing (LBBAP) in patients with LBBB.

Methods

From Apr 2014 to Aug 2018, patients with LBBB from multicenters indicated for CRT or pacing therapy were included. LBBAP was performed by advancing the MDT 3830 lead deep into the septum about 1 cm distal to the His bundle region (Figure 1F). Pacing characteristics, success rate, threshold and R-wave amplitude were assessed.

Results

A total of 94 patients aged 68.3±10.7 y with the native QRS duration of 167.2±17.2 ms were included. In 92 patients, LBBAP was successfully achieved and demonstrated RBBB pattern during unipolar tip pacing (UTP), with the paced QRS duration of 116.4±12.6ms (Figure 1C). Fusion of LBBAP and native conduction via the RBB eliminated RBBB and resulted in an average QRS duration of 103.2±10.1 ms (Figure 1D). LBB potential could be recorded from the LBB lead during correction of LBBB by HBP in 21 patients who used two leads method (His lead and LBB lead, Figure 1B). Output dependent selective and non-selective LBBAP were demonstrated in 48 patients (Figure 1C, D). The LBB capture threshold by UTP was 0.53±0.18V/0.5ms at acute and 0.62±0.17V/0.5ms at 6 months and 0.65±0.2V/0.5ms at 1 year. The R-wave amplitude were 11.4±5.2mV, 12.4±5.8mV and 12.0±5.8mV at acute, 6 month and 1 year. During follow-up, only one patient had an increase in LBB capture threshold to 2.5V/0.5ms at 3 months and there were no other complications such as dislodgment, infections, embolism or stroke associated with the implantation.

Conclusion

Permanent LBBAP is feasible and safe in patients with LBBB.

[Correlation between postoperative neutrophil to lymphocyte ratio and recurrence and prognosis of hepatocellular carcinoma after radical liver resection]

Objective: To investigate the correlation between postoperative peripheral blood neutrophil to lymphocyte ratio (NLR) and recurrence and prognosis of patients with hepatocellular carcinoma (HCC). Methods: The clinicopathological and follow-up data of 344 patients with HCC who underwent radical liver resection from May 2010 to April 2014 were analyzed retrospectively. Results: Of the 344 patients, 104 had early recurrence and 84 had late recurrence. Receiver operating characteristic (ROC) curve analysis showed that the NLR predicted area under the curve (AUC) of early recurrence was 0.622 (P<0.001), the optimal cut-off value was 2.41. The AUC of late recurrence was 0.634 (P=0.001), the optimal cut-off value was 2.15. Cox multivariate analysis showed the serum concentration of hepatitis B surface antigen (HR=2.508, 95% CI: 1.311-4.798), microvascular invasion (HR=2.422, 95% CI: 1.239-4.734), Milan criteria (HR=2.373, 95% CI: 1.427-3.948) and postoperative NLR (HR=2.285, 95% CI: 1.379-3.788) were independent risk factors of early recurrence after HCC resection. Postoperative NLR (HR=2.927, 95% CI: 1.630-5.255), liver cirrhosis (HR=2.531, 95% CI: 1.291-4.962) and serum concentration of albumin (HR=2.257, 95% CI: 1.251-4.073) were independent risk factors of late recurrence after HCC resection. The median recurrence-free survival (RFS) of the 344 patients was 45.0 months, and the median overall survival (OS) was 63.2 months. ROC curve analysis showed that the postoperative NLR predicted 5-year survival AUC was 0.689 (P<0.05), with an optimal cutoff of 2.29. Cox multivariate analysis showed microvascular invasion (HR=2.247, 95% CI: 1.534-3.291), postoperative NLR (HR=2.217, 95% CI: 1.653-2.974), and liver cirrhosis (HR=1.685, 95% CI: 1.168-2.431), Milan criteria (HR=1.679, 95% CI: 1.238-2.277), serum concentration of hepatitis B surface antigen (HR=1.623, 95% CI: 1.102-2.392), serum concentration of albumin (HR=1.43, 95% CI: 1.066-1.918) were independent factors of RFS after HCC resection, while microvascular invasion (HR=3.862, 95% CI: 2.407-6.197), Barcelona staging (HR=2.864, 95% CI: 1.600-5.125), postoperative NLR (HR=2.688, 95% CI: 1.782-4.055), liver cirrhosis (HR=2.039, 95% CI: 1.184-3.514), serum concentration of albumin (HR=1.81, 95% CI: 1.204-2.720) were independent factors of OS. Conclusions: For HCC patients who receive radical liver resection, postoperative NLR ≥2.29 implicates poor prognosis. Moreover, postoperative NLR ≥2.41 suggests early recurrence, while NLR ≥2.15 suggests late recurrence.

[A new prognostic score system of hepatocellular carcinoma following hepatectomy]

Objective: To establish a new scoring system based on the clinicopathological features of hepatocellular carcinoma (HCC) to predict prognosis of patients who received hepatectomy. Methods: A total of 845 HCC patients who underwent hepatectomy from 1999 to 2010 at Cancer Hospital, Chinese Academy of Medical Sciences were retrospectively analyzed. 21 common clinical factors were selected in this analysis. Among these factors, the cut-off values of alpha-fetoprotein (AFP), alkaline phosphatase (ALP) and intraoperative blood loss were evaluated by using a receiver operating characteristic (ROC) curve analysis.The Kaplan-Meier method and Cox regression model were used to evaluate the independent risk factors associated with the prognosis of HCC patients after hepatectomy. HCC postoperatively prognostic scoring system was established according to the minimum weighted method of these independent risk factors, and divided the patients into 3 risk groups, including low-risk, intermediate-risk and high-risk group. The relapse-free survival (RFS) and overall survival (OS) were compared among these groups. Results: The univariate analysis showed that clinical symptoms, preoperative α-fetoprotein (AFP) level, serum alkaline phosphatase (ALP) level, tumor size, tumor number, abdominal lymph node metastasis, macrovascular invasion or tumor thrombus, extrahepatic invasion or serosa perforation, the severity of hepatic cirrhosis, intraoperative blood loss, the liver operative method, pathological tumor thrombus, intraoperative blood transfusion, perioperative blood transfusion were significantly associated with median RFS of these HCC patients (P<0.05). Alternatively, clinical symptoms, preoperative AFP level, serum ALP level, tumor size, tumor number, abdominal lymph node metastasis, macrovascular invasion or tumor thrombus, extrahepatic invasion or serosa perforation, the severity of hepatic cirrhosis, intraoperative blood loss, the liver operative method, pathological lymphocyte invasion, pathological tumor thrombus, intraoperative blood transfusion, perioperative blood transfusion were significantly associated with the median OS of these HCC patients (P<0.05). The multivariate analysis showed that AFP ≥20 ng/ml, clinical symptoms, tumor diameter ≥5 cm, multiple tumors, macrovascular invasion or tumor thrombus, extrahepatic invasion or serosa perforation, moderate and severe liver cirrhosis, non- anatomic resection were the independent risk factors of RFS and OS (P<0.05). The independent risk factor of RFS was intraoperative bleeding loss ≥325 ml (P<0.05); The independent risk factors of OS were abdominal lymph node metastasis and pathological tumors thrombus (P<0.05). The respective weight of 11 independent factors was used to establish the scoring system (scores range from 0 to 26). In the score system, 0 to 5 points were defined as the low-risk group (286 cases), 6 to 12 points were determined as the intermediate-risk group (503 cases), more than 13 points were classified as the high-risk group (56 cases). The median RFS of the low-risk, intermediate-risk and high-risk group were 80, 27 and 6 months, respectively. The differences were statistically significant (P<0.001). The median OS of the three groups were 134, 51 and 15 months, respectively, and the differences were statistically significant (P<0.001). Conclusion: This new score system provides effective prediction of postoperative prognosis for HCC patients.

[The clinical characteristics, diagnosis and treatment of patients with gout in China]

Objective: To investigate the demographic characteristics, clinical features, diagnosis and treatment of patients with gout in China. Methods: Clinical data of 6 814 patients with gout from 100 hospitals in 27 provinces, municipalities or autonomous regions in China were collected and analyzed. Results: (1) The ratio of male to female in patients with gout was 14.7∶1. The mean age of onset was (48.8±15.1) years old. Mean serum urate level was (526.7±132.3) μmol/L. Patients' education background was of U-shaped distribution; (2) Hypertension was the most common comorbidity [15.8%(1 079/6 814)], then overweight or obesity [51.9%(3 536/6 814)]; (3) Alcohol and high-purine food intake were dominant triggering factors in men. The diagnosis of gout was made after onset in majority of patients with cardinal symptom arthralgia. Most patients had the disease less than 5 years, and the longer the course, the more flares in the previous year of entry; (4) Febuxostat was the mostly used urate-lowering medication. 20.7%(1 412/6 814), 10.8%(739/6 814) and 3.9%(265/6 814) of patients were followed up in 4 weeks, 12 weeks and 24 weeks after registration, and 18.9%(267/1 412), 29.1%(215/739) and 38.1%(101/265) of them reached the control target of serum urate levels, respectively. After treatment, patients' liver function was not affected, but serum creatinine levels decreased significantly. Conclusions: The proportion of gout patients who reach target serum urate level is very low. Further steps including education and survey need to be carried on.

Determining the Effect of Drying Time on Phosphorus Solubilization from Three Agricultural Soils under Climate Change Scenarios

Climate projections for the future indicate that the United Kingdom will experience hotter, drier summers and warmer, wetter winters, bringing longer dry periods followed by rewetting. This will result in changes in phosphorus (P) mobilization patterns that will influence the transfer of P from land to water. We tested the hypothesis that changes in the future patterns of drying-rewetting will affect the amount of soluble reactive phosphorus (SRP) solubilized from soil. Estimations of dry period characteristics (duration and temperature) under current and predicted climate were determined using data from the UK Climate Projections (UKCP09) Weather Generator tool. Three soils (sieved <2 mm), collected from two regions of the United Kingdom with different soils and farm systems, were dried at 25°C for periods of 0, 2, 4, 5, 6, 8, 10, 15, 20, 25, 30, 60, and 90 d, then subsequently rewetted (50 mL over 2 h). The solubilized leachate was collected and analyzed for SRP. In the 2050s, warm period temperature extremes >25°C are predicted in some places and dry periods of 30 to 90 d extremes are predicted. Combining the frequency of projected dry periods with the SRP concentration in leachate suggests that this may result overall in increased mobilization of P; however, critical breakpoints of 6.9 to 14.5 d dry occur wherein up to 28% more SRP can be solubilized following a rapid rewetting event. The precise cause of this increase could not be identified and warrants further investigation as the process is not currently included in P transfer models.

Lattice Boltzmann method for the fractional advection-diffusion equation

Mass transport, such as movement of phosphorus in soils and solutes in rivers, is a natural phenomenon and its study plays an important role in science and engineering. It is found that there are numerous practical diffusion phenomena that do not obey the classical advection-diffusion equation (ADE). Such diffusion is called abnormal or superdiffusion, and it is well described using a fractional advection-diffusion equation (FADE). The FADE finds a wide range of applications in various areas with great potential for studying complex mass transport in real hydrological systems. However, solution to the FADE is difficult, and the existing numerical methods are complicated and inefficient. In this study, a fresh lattice Boltzmann method is developed for solving the fractional advection-diffusion equation (LabFADE). The FADE is transformed into an equation similar to an advection-diffusion equation and solved using the lattice Boltzmann method. The LabFADE has all the advantages of the conventional lattice Boltzmann method and avoids a complex solution procedure, unlike other existing numerical methods. The method has been validated through simulations of several benchmark tests: a point-source diffusion, a boundary-value problem of steady diffusion, and an initial-boundary-value problem of unsteady diffusion with the coexistence of source and sink terms. In addition, by including the effects of the skewness β, the fractional order α, and the single relaxation time τ, the accuracy and convergence of the method have been assessed. The numerical predictions are compared with the analytical solutions, and they indicate that the method is second-order accurate. The method presented will allow the FADE to be more widely applied to complex mass transport problems in science and engineering.

Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments

We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target controllable risk factors, such as soil nutrient status, soil condition and crop cover.

Treatment of seawater immersion-complicated open-knee joint fracture

The current study aimed to select suitable remedies for seawater immersion-complicated open-knee joint fracture by exploring the effects of different treatment methods. Forty adult rabbits weighing 2.20 ± 0.25 kg were divided equally into internal fracture fixation group (A), seawater-immersed group with primary internal fixation (B), seawater-immersed group with secondary internal fixation (C), and seawater-immersed group with external fixation (D), using the random-digit table method. Open-femoral internal condylar fracture models were established. Group A was left untreated for 2 h, whereas the other three groups were subjected to seawater immersion for 2 h. Afterwards, groups A and B underwent debridement and steel plate and screw internal fixation. Group C underwent debridement and external fixation, which was followed by secondary steel plate and screw internal fixation after the wound healed. Group D underwent transarticular arthrodesis. Wound infection, joint functional rehabilitation, and radiological and histopathological changes in fracture healing in each group were assessed. The results showed that delayed internal fixation effectively reduces the infection rate of seawater immersion-complicated open fracture and benefits joint function rehabilitation.

Changes in the expression of telomere maintenance genes might play a role in the pathogenesis of systemic lupus erythematosus

Previous studies demonstrated that telomerase activity increased while telomere length shortened in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). This study aimed to examine the changes of telomere maintenance genes and their clinical significance in SLE. The mRNA level of telomeric proteins in PBMCs, including shelterin complex (TRF1, TRF2, POT1, TPP1, TIN2 and hRAP1), a set of multifunctional proteins involved in telomere maintenance (MRE11, KU80 and RPA1), and Ki67, was measured using real-time quantitative PCR in 56 SLE patients (36 treated and 20 untreated; 32 with renal involvement and 24 without renal involvement) and 46 healthy subjects (controls). The expression of TPP1, TIN2, POT1 and KU80 was significantly reduced while that of TRF2 and MRE11 increased in SLE patients ( p < 0.05, respectively); significant difference was not found in the expression of TRF1, hRAP1, RPA1 and Ki67 ( p > 0.05, respectively). The expression of TRF2, MRE11 and Ki67 was much higher in untreated SLE patients than in controls or treated SLE patients ( p < 0.05, respectively); the expression of hRAP1 was much higher in SLE patients with renal involvement than in controls or SLE patients without renal involvement ( p < 0.05, respectively). Significant positive correlation was found between level of KU80 and C3, TPP1 and TIN2, TPP1 and POT1, while significant negative correlation was found between KU80 and serum total globulins, TIN2 and RF, TPP1 and SLEDAI score ( p < 0.05, respectively). In conclusion, altered expression of telomere maintenance genes might be involved in the pathogenesis of SLE. Further study in expression and functions of telomeric proteins would be needed.

[The clinical assessment of zygomatic complex fracture treated via infraorbital incision and rigid fixation]

OBJECTIVE

To investigate the clinical effect of zygomatic complex (ZC) fracture via infraorbital incision and rigid fixation.

METHODS

To clinically classify 65 cases with ZC fractures,which treated with open reduction and minor titanium-plate internal fixation.

RESULTS

(1) The operated area can be widely exposed via infraorbital incision. (2) ZC fractures can be reducted timely and correctly. (3) The fragments can be fixed rigidly with minor Ti-plaets. No injury to the facial nerve.The satisfactory rate of recovery was 95.4% (63/65).

CONCLUSION

Operation through infraorbital incision is suitable to ZC fractures.

[Study on the structure of epimerides of cycloclausenamide]

AIM

To study the structures of the epimerides of cycloclausenamide.

METHODS

The structures of compound I, extracted from Clausena lansium (Lour.) Skeels, and synthesized compound III were determined by single crystal X-ray diffraction analysis. The stereo-structures of compound II and IV were also built up through Tripos force field based on crystal structures of compound I and III.

RESULTS

The molecular formula and molecular weight were found to be C18H17O2N and 279.34 respectively. Compound I crystallized in monoclinic system, space group P2(1) with a = 0.5928(1), b = 1.5014(1), c = 1.6190(1) nm, V = 1.4410(3) nm3, Z = 4, Dx = 1.288 g.cm-3, Rf = 0.075, Rw = 0.073(w = 1/sigma 2|F|), S = 3.983; compound III crystallized in triclinic system, space group P1 with a = 0.5667(1), b = 1.2934(1), c = 2.1119 (1) nm, alpha = 102.17(1), beta = 90.25(1), gamma = 102.65(2) degrees, V = 1.4770(5) nm3, Z = 4, Dx = 1.224 g.cm-3, Rf = 0.047, Rw = 0.051(w = 1/sigma 2|F|), S = 0.467.

CONCLUSION

These results showed that compound I and III both are cycloclausenamide except that the directions of the phenyl group on C6 are different. Cycloclausenamide can form 4 pairs of epimerides but the directions of the phenyl group does not affect their energy in free state.

[Study on the effect of hyperbaric oxygen on apoptosis in the CA1 region of hippocampus following forebrain ischemia reperfusion]

AIM AND METHODS

To study the mechanism of hyperbaric oxygen (HBO) on the treatment of cerebral ischemia, and to provide theoretical basis for hyperbaric oxygen treatment (HBOT), we examined the effect of 0.15 MPa and 0.25 MPa HBO treatment (60 min/d, for 3 successive days ) on ischemia reperfusion - induced apoptosis in gerbil hippocampus CA1 using TUNEL staining method.

RESULTS

The number of neuronal apoptosis in hippocampus CA1 was significantly decreased in HBOT groups(P < 0.01). Neuronal apoptosis in hippocampus CA1 in 0.25 MPa groups were less than that in 0.15 MPa groups (P < 0.01).

CONCLUSION

HBOT is effective in reducing neuronal apoptosis and in protecting neurons from injury of ischemia reperfusion, and 0.25 MPa is an appropriate pressure for HBOT.

[Effect of hyperbaric oxygen on the expression of proteins Bcl-2 and Bax in the gerbil hippocampus CA1 following forebrain ischemia reperfusion]

AIM

To study the mechanisms of how hyperbaric oxygen treatment (HBOT) reduced neuronal apoptosis following forebrain ischemia reperfusion.

METHODS

Changes of the expression of protein Bcl-2 or Bax were observed in CA1 region of gerbil hippocampus following HBOT on ischemia reperfusion 3 days using the method of labelled streptavidin biotin (LSAB) immunohistochemistry staining. For this purpose gerbils were exposed to the 0.15 MPa and 0.25 MPa HBO 60 min every day for 3 successive days.

RESULTS

The expression of protein Bcl-2 in hippocampus CA1 was significantly increased in HBOT groups (P < 0.01), and changes in 0.25 MPa groups were greater than those in 0.15 MPa groups (P < 0.01). The expression of protein Bax in hippocampus CA1 was not changed significantly in HBOT groups.

CONCLUSION

HBO can induce the expression of Bcl-2, which is the mechanism of neuronal protecting effect of HBOT.

Escherichia coli nusG mutations that block transcription termination by coliphage HK022 Nun protein

The Escherichia coli nusG gene product is required for transcription termination by phage HK022 Nun protein at the lambda nutR site in vivo. We show that it is also essential for Nun termination at lambda nutL. Three recessive mis-sense nusG mutations have been isolated that inhibit termination by Nun at lambda nutR. The mutations are ineffective in a lambda pL nutL fusion, even when lambda nutR replaces lambda nutL. The mutant strains support lambda growth, indicating that lambda N antitermination activity is not impaired. Transcription arrest by Nun in vitro is stimulated by NusG protein at both lambda nutR and lambda nutL. Mutant NusG protein fails to enhance transcriptional arrest by Nun at either site. The mutant protein, like the wild-type protein, suppresses transcriptional pausing by RNA polymerase and stimulates Rho-dependent termination. These results imply that the role of NusG in Nun termination may be distinct from its roles in other transcription reactions.

Translational repression by a transcriptional elongation factor

One of the classical positive regulators of gene expression is bacteriophage lambda N protein. N regulates the transcription of early phage genes by participating in the formation of a highly processive, terminator-resistant transcription complex and thereby stimulates the expression of genes lying downstream of transcriptional terminators. Also included in this antiterminating transcription complex are an RNA site (NUT) and host proteins (Nus). Here we demonstrate that N has an additional, hitherto unknown regulatory role, as a repressor of the translation of its own gene. N-dependent repression does not occur when NUT is deleted, demonstrating that N-mediated antitermination and translational repression both require the same cis-acting site in the RNA. In addition, we have identified one nut and several host mutations that eliminate antitermination and not translational repression, suggesting the independence of these two N-mediated mechanisms. Finally, the position of nutL with respect to the gene whose expression is repressed is important.

Effects of theophylline and cyclohexyladenosine on brain injury following normo- and hyperglycemic ischemia: a histopathologic study in the rat

The present study was designed to determine the effects of theophylline, an adenosine receptor antagonist, and cyclohexyladenosine (CHA), an adenosine receptor agonist, on ischemic brain injury following normo- and hyperglycemic ischemia and reperfusion in fasted male Wistar rats. Moderate hyperglycemia was achieved by administering 17% D-glucose (3 g/kg i.p.), whereas normoglycemic animals received an equal volume of saline. The animals were further divided into two groups: One group was pretreated with either theophylline (0.20 mumol/g i.p.) or an equal volume of saline; the second group received either intraventricular CHA (6.25 nmol) or mock CSF prior to the onset of ischemia. During ischemia, pericranial temperature was maintained at 36 degrees C and EEG was monitored. Cerebral ischemia was induced for 15 min, after which flow was restored and the animals were allowed to recover completely. There were no significant differences in physiologic parameters among the groups studied. Five days following the ischemic episode, the rats were perfused with formalin and the brains subserially sectioned (8 microns) in the coronal plane and stained with celestine blue/acid fuchsin. Histopathologic analysis was performed in a blinded fashion to determine percentage of dead neurons. Hyperglycemic animals had significantly greater ischemic injury in CA1, cortex, and caudate than the normoglycemic group (p < 0.01). Moreover, rats pretreated with theophylline had a significantly (p < 0.01) higher percentage of dead neurons in CA1, cortex, and caudate than corresponding controls.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on dissolution of icariin from wuxian huichun capsules]

The accumulated dissolution of icariin from the traditional Chinese Wuxian Huichun capsules has been determined by roll-basket and three-wavelength UV spectrophotometry within 100 minutes. The values of T50 and Td for samples c, d are significantly greater than those for a, b. It is thus essential to determine the dissolution as a means to control the quality of capsules.

Reversible focal ischemia in the rat: effects of halothane, isoflurane, and methohexital anesthesia

Barbiturates and the volatile anesthetic isoflurane reduce CMR to similar values. If the mechanism of barbiturate protection against focal ischemic injury is due to a reduction in cellular energy requirements, then isoflurane should similarly reduce ischemic injury. To evaluate this, spontaneously hypertensive rats underwent 2 h of reversible middle cerebral artery occlusion (MCAO) while receiving deep methohexital, isoflurane, or halothane anesthesia. Ninety-six hours postischemia, neurologic deficits were present but without a difference between groups. Mean +/- SD infarct volume, as assessed by triphenyl tetrazolium chloride staining and computerized planimetry, was significantly less in the methohexital group (n = 8; 166 +/- 74 mm3) than in either the halothane (n = 9; 249 +/- 71 mm3; p less than 0.04) or the isoflurane (n = 9; 243 +/- 62 mm3; p less than 0.03) groups. One possible explanation for the lack of protective effect for isoflurane might be related to its vasodilative properties, which could result in a cerebral vascular steal. To examine this possibility, rats anesthetized with methohexital or isoflurane underwent autoradiographic determination of CBF with or without MCAO. In isoflurane-anesthetized sham rats (n = 5; no ischemia), CBF was approximately three times greater than in methohexital-treated (n = 5) sham rats. During ischemia, although a regional reduction in flow was noted in both anesthetic groups, mean flow remained greater in the isoflurane group.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of hyperglycemia on cerebral adenosine production during ischemia and reperfusion

We hypothesized that systemic hyperglycemia would alter cerebral adenosine concentrations during ischemia and reperfusion. In the present study, we analyzed brain tissue and cerebrospinal fluid (CSF) from hyperglycemic and normoglycemic rats before ischemia, after 15 min of incomplete forebrain ischemia, and during 60 min of reperfusion. Hyperglycemic rats received 3 g/kg of 17% D-glucose intraperitoneally, which increased blood glucose to 357 +/- 23 mg/100 ml compared with 128 +/- 12 mg/100 ml in normoglycemic rats. Brain tissue was sampled by the freeze-blow technique, and CSF was obtained by collecting cortical perfusate from the closed cranial window. Tissue and CSF were analyzed for adenosine and its metabolites inosine and hypoxanthine, and tissue was also analyzed for adenine nucleotides. Hyperglycemia significantly attenuated the increase in brain tissue and CSF adenosine and its metabolites during ischemia while preserving adenine nucleotide concentrates. This attenuation of ischemic adenosine production persisted after 5 min of reperfusion in tissue and throughout 60 min of reperfusion in CSF. Because adenosine, a cerebral vasodilator, can inhibit the release of neuronal excitotoxins as well as affect neutrophil-endothelial interactions, adenosine has been proposed as an endogenous neuroprotector. Thus the attenuation of adenosine and its metabolites may be a factor in the pathogenesis of increased ischemic brain injury associated with systemic hyperglycemia.

Nitrous oxide does not alter infarct volume in rats undergoing reversible middle cerebral artery occlusion

This experiment was designed to determine if nitrous oxide alters neurologic and pathologic outcome from temporary focal cerebral ischemia in spontaneously hypertensive rats deeply anesthetized with a barbiturate. Two groups of rats were given intravenous methohexital such that a stable EEG pattern of burst suppression was achieved. In one group of rats (n = 11), the lungs were mechanically ventilated with 70% N2O/30% O2, and in the other group (n = 10), ventilation was done with 70% nitrogen/30% O2. The middle cerebral artery was then occluded for 2 h, during which time mean arterial pressure, blood gases, hematocrit, plasma glucose, and head temperature were held constant between groups. The total doses of methohexital administered were similar in both groups as were the plasma methohexital concentrations immediately prior to onset of ischemia. After reperfusion of the middle cerebral artery, the animals were allowed to awaken. Neurologic evaluations were performed prior to ischemia and at 24 and 96 h postischemia. Cerebral infarct volume was measured at 96 h postischemia using triphenyl tetrazolium chloride staining and computer imaging techniques. There were no neurologic differences between the N2O and nitrogen groups at any experimental interval although both groups exhibited deficits at both 24 and 96 h postischemia relative to preischemic values. The two groups also had nearly identical cerebral infarct volumes (N2O = 231 +/- 97 mm3; nitrogen = 226 +/- 75 mm3; mean +/- SD).(ABSTRACT TRUNCATED AT 250 WORDS)

Construction of a bivalent oral vaccine for prevention of typhoid fever and cholera diarrhea

A recombinant plasmid pMM-CTB containing the gene for production of the nontoxic B subunit of Vibrio cholera was transferred into a safe, effective and attenuated oral vaccine Ty21a strain of Salmonella typhi. The resulting Ty21a (pMM-CTB) could steadily produce CT-B subunit that was secreted extracellularly and had the same antigenicity as CT-B produced by V. cholera. Furthermore, the characteristics of the antigenicity, the persistance in mice and the galactose sensitivity possessed in the strain of Ty21a were also retained in Ty21a (pMM-CTB). A bivalent vaccine containing Ty21a (pMM-CTB) and the killed whole cell of V. cholera was then constructed which had good immunogenecity for typhoid fever and cholera diarrhea.

EEG changes during carotid occlusion and hypotension in the rat: the effects of nitrous oxide

It has been suggested that N2O may alter the sensitivity of the brain to ischemia. To test this hypothesis. we examined the effects of N2O on the development of left-right hemispheric asymmetry in the electroencephalogram (EEG) during hemorrhagic hypotension in rats subjected to unilateral carotid occlusion. Rats were anesthetized with halothane/O2/air, and ventilated to normocarbia (PaCO2 approximately 40 mm Hg). Catheters were placed in the femoral artery and vein, and both common carotid arteries (CCA) were exposed. Bilateral fronto-occipital screws were then placed to record left and right hemispheric EEGs, which were processed by computer and stored on disc. Animals were then randomly assigned to one of three treatment groups (n = 8 each): group 1, 0.5 MAC (0.5%) halothane + 0.5 MAC (70%) N2O; group 2, 1 MAC (1.0%) halothane + 70% nitrogen; and group 3, 1 MAC halothane + 70% N2O. After stabilization, the left CCA were occluded. Animals with EEG changes at this point were discarded. Beginning 5 min later, venous blood withdrawal was started at a rate of 0.25 ml/min, while mean arterial blood pressure (MAP) and EEG were continuously recorded. After exsanguination was complete, EEG data (raw and processed) were re-examined by an individual who was unaware of the anesthetics administered to determine the MAP at which any evidence of EEG asymmetry appeared. There were no intergroup differences in weight, PaO2, PaCO2, pHa, blood glucose. hematocrit, or starting (prebleed) MAP. The earliest change in the EEG was typically a decrease in total amplitude over the hemisphere ipsilateral to the carotid occlusion. Adding 70% N2O to a 1 MAC halothane background (group 2 vs. group 3) had no effect on the MAP at which this EEG asymmetry appeared (54 +/- 13 vs. 53 +/- 10 mm Hg). However, this MAP was significantly higher in animals breathing 0.5 MAC halothane + 0.5 MAC N2O (group 1, 78 +/- 17 mm Hg, p = 0.0019 by ANOVA). We conclude that 70% N2O had no direct effects on the MAP at which EEG abnormalities appear (group 2 vs. 3), and that the observed differences are more closely related to the concentration of volatile agent. Whether these differences are related to anesthetic-induced differences in the brain's tolerance to reduced CBF or whether there are differences in cerebral blood flow (CBF) autoregulation are unknown.

Cerebral autoregulation following prophylactic and delayed experimental STA-MCA bypass

Cerebral autoregulation is impaired in ischaemic regions. We hypothesized that pre-existing STA-MCA bypass would be superior to delayed revascularization in maintaining ipsilateral rCBF and preserving cerebral autoregulation following experimental stroke. Two series of dogs were tested to evaluate this hypothesis, but which was disproved for the chosen experimental conditions. In the first, eight dogs underwent craniotomy, STA-MCA bypass, and radiolabeled microsphere rCBF determinations. Blood pressure was manipulated with intravenous adenosine and levarterenol. Ischaemic zone rCBF was measured at MAP 60 mm Hg (97.2 ml.min-1.100 g-1) and MAP 140 mm Hg (113.6) (p = NS), in the intact arterial system with the patent bypass in place. An hemispheric ipsilateral ischaemic lesion was then created, and three further microsphere rCBF determinations were made at MAP 60 mm Hg (41.7 ml.min-1.100 g-1), MAP 100 mm Hg (52.6) and MAP 140 mm Hg (58.3). There were no significant differences between these measurements (ANOVA p = NS). In a second series of five animals the bypass was placed and the stroke lesion created first. Ischaemic zone rCBF was then measured at MAP 60 mm Hg (35 ml.min-1 . 100 g-1) and MAP 140 mm Hg (44 ml.min-1 . 100g-1) (p = NS), with the patent bypass in place. The bypass was then clamped for 15 minutes and profound ischaemia confirmed (5 ml.min-1 . 100 g-1, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning and structure of the BepI modification methylase

The gene coding for a CGCG specific DNA methylase has been cloned in E. coli from Brevibacterium epidermidis. The enzyme, named BepI methylase, is probably the cognate methylase of the FnuDII isoschizomer BepI endonuclease isolated from this strain. The expression of BepI methylase in E. coli is dependent on the orientation of the cloned fragment suggesting that the gene is transcribed from a promoter on the plasmid vector. No BepI endonuclease could be detected in the clones producing BepI methylase. The nucleotide sequence of the BepI methylase gene has been determined, it predicts a protein of 403 amino acids (MR: 45,447). Analysis of the amino acid sequence deduced from the nucleotide sequence revealed similarities between the BepI methylase and other cytosine methylases. M. BepI methylates the external cytosine in its recognition sequence.

The expression of enterotoxin A-B+ gene of V. cholerae in E. coli

The cloning in E. coli of a cholerae toxin gene that is A-B+ has been successfully constructed by using DNA recombinant techniques. E. coli cells carrying the recombinant plasmid pMM-CTB have been shown to produce a large amount of CTB subunits which are secreted as extracellular proteins.