[Influence of visceral lipids obesity on the early postoperative complications after radical gastrectomy]

Objective: To investigate the effect of visceral fat area (VFA) on the surgical efficacy and early postoperative complications of radical gastrectomy for gastric cancer. Methods: A retrospective cohort study method was used. Clinicopathological data and preoperative imaging data of 195 patients who underwent D2 radical gastric cancer surgery at the First Affiliated Hospital of Xi'an Jiaotong University from January 2014 to December 2017 were analyzed retrospectively. Inclusion criteria: (1) complete clinicopathological and imaging data; (2) malignant gastric tumor diagnosed by preoperative pathology, and gastric cancer confirmed by postoperative pathology; (3) no preoperative complications such as bleeding, obstruction or perforation, and no distant metastasis. Those who had a history of abdominal surgery, concurrent malignant tumors, poor basic conditions, emergency surgery, palliative resection, and preoperative neoadjuvant therapy were excluded. The VFA was calculated by software and VFA ≥ 100 cm² was defined as visceral obesity according to the Japan Obesity Association criteria . The patients were divided into high VFA (VFA-H, VFA≥100 cm², n=96) group and low VFA (VFA-L, VFA<100 cm², n=99) group . The clinicopathological characteristics, surgical outcomes and early postoperative complications were compared between the two groups. Univariate and multivariate Logistic regression models were used to analyze the risk factors of early complications. Receiver operating characteristic (ROC) curve was used to analyze predictive values of VFA for early complications. Pearson's χ² test was used to analyze the correlation between BMI and VFA. Results: There were no significant differences in terms of gender, age, American Society of Anesthesiologists physical status classification, preoperative comorbidities, preoperative anemia, tumor TNM staging, N staging, T staging and tumor differentiation, surgical method, extent of resection, and tumor location between the VFA-L group and the VFA-H group (all P>0.05). However, patients in the VFA-H group had higher BMI, larger tumor, lower rate of hypoalbuminemia and greater subcutaneous fat area (SFA) (all P<0.05). The VFA-H group presented significantly longer operation time and significantly less number of harvested lymph nodes as compared to the VFA-L group (both P<0.05). However, there were no significant differences in intraoperative blood loss, conversion to laparotomy and postoperative hospital stay (all P>0.05). Complications of Clavien-Dindo grade II and above within 30 days after operation were mainly anastomosis-related complications (leakage, bleeding, infection and stricture), intestinal obstruction and incision infection. The VFA-H group had a higher morbidity of early complications compared to the VFA-L group [24.0% (23/96) vs 10.1% (10/99), χ²=6.657, P=0.010], and the rates of anastomotic complications and incision infection were also higher in the VFA group [10.4% (10/96) vs. 3.0% (3/99), χ²=4.274, P=0.039; 7.3% (7/96) vs. 1.0% (1/99), P=0.033]. Multivariate logistic analysis showed that high BMI (OR=3.688, 95%CI: 1.685-8.072, P=0.001) and high VFA (OR=2.526, 95%CI: 1.148-5.559,P=0.021) were independent risk factors for early complications. The area under the ROC curve (AUC) of VFA for predicting early complications was 0.645, which was higher than that of body weight (0.591), BMI (0.624) and SFA (0.626). Correlation analysis indicated that there was a significantly positive correlation between BMI and VFA (r=0.640, P<0.001). Conclusion: VFA ≥ 100 cm² is an independent risk factor for early complications after radical gastrectomy for gastric cancer.It can better predict the occurrence of above early postoperative complications.

Pulse chirp enhances the laser acceleration of neutral particles

Accelerating neutral atoms is challenging because such particles are not directly manipulated by electric and magnetic fields as charged particles. In our acceleration scheme, the excited atom requires a sufficiently high gradient acceleration force. The key challenge in laser acceleration experiments is that not only must the photon energy excite atoms to the Rydberg state, but also atoms must not be ionized in an intense laser field. In this Letter, we propose using a chirped laser pulse to achieve the objectives above. The enhancement effect of the pulse chirp on the laser acceleration of neutral particles is investigated via numerical simulation and analytical analysis.

[Efficacy of laparoscopic proximal gastrectomy with double-tract reconstruction versus laparoscopic total gastrectomy with Roux-en-Y reconstruction for early upper gastric cancer]

Objective: To compare clinical efficacy between laparoscopic radical proximal gastrectomy with double-tract reconstruction (LPG-DTR) and laparoscopic radical total gastrectomy with Roux-en-Y reconstruction (LTG-RY) in patients with early upper gastric cancer, and to provide a reference for the selection of surgical methods in early upper gastric cancer. Methods: A retrospective cohort study method was carried out. Clinical data of 80 patients with early upper gastric cancer who underwent LPG-DTR or LTG-RY by the same surgical team at the Department of General Surgery, the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to January 2021 were retrospectively analyzed. Patients were divided into the DTR group (32 cases) and R-Y group (48 cases) according to surgical procedures and digestive tract reconstruction methods. Surgical and pathological characteristics, postoperative complications (short-term complications within 30 days after surgery and long-term complications after postoperative 30 days), survival time and nutritinal status were compared between the two groups. For nutritional status, reduction rate was used to represent the changes in total protein, albumin, total cholesterol, body mass, hemoglobin and vitamin B12 levels at postoperative 1-year and 2-year. Non-normally distributed continuous data were presented as median (interquartile range), and the Mann-Whitney U test was used for comparison between groups. The χ(2) test or Fisher's exact test was used for comparison of data between groups. The Mann-Whitney U test was used to compare the ranked data between groups. The survival rate was calculated by Kaplan-Meier method categorical, and compared by using the log-rank test. Results: There were no statistically significant differences in baseline data betweeen the two groups, except that patients in the R-Y group were oldere and had larger tumor. Patients of both groups successfully completed the operation without conversion to laparotomy, combined organ resection, or perioperative death. There were no significant differences in the distance from proximal resection margin to superior margin of tumor, postoperative hospital stay, time to flatus and food-taking, hospitalization cost, short- and long-term complications between the two groups (all P>0.05). Compared with the R-Y group, the DTR group had shorter distal margins [(3.2±0.5) cm vs. (11.7±2.0) cm, t=-23.033, P<0.001], longer surgery time [232.5 (63.7) minutes vs. 185.0 (63.0) minutes, Z=-3.238, P=0.001], longer anastomosis time [62.5 (17.5) minutes vs. 40.0 (10.0) minutes, Z=-6.321, P<0.001], less intraoperative blood loss [(138.1±51.6) ml vs. (184.3±62.1) ml, t=-3.477, P=0.001], with significant differences (all P<0.05). The median follow-up of the whole group was 18 months, and the 2-year cancer-specific survival rate was 97.5%, with 100% in the DTR group and 95.8% in the R-Y group (P=0.373). Compared with R-Y group at postoperative 1 year, the reduction rate of weight, hemoglobin and vitamin B12 were lower in DTR group with significant differences (all P<0.05); at postoperative 2-year, the reduction rate of vitamin B12 was still lower with significant differences (P<0.001), but the reduction rates of total protein, albumin, total cholesterol, body weight and hemoglobin were similar between the two groups (all P>0.05). Conclusions: LPG-DTR is safe and feasible in the treatment of early upper gastric cancer. The short-term postoperative nutritional status and long-term vitamin B12 levels of patients undergoing LPG-DTR are superior to those undergoing LTG-RY.

Neutral particles pushed or pulled by laser pulses: erratum

We present an erratum to our Letter [Opt. Lett.41, 230 (2016)10.1364/OL.41.000230]. This erratum corrects three typing errors. The corrections have no influence on the results and conclusions of the original Letter.

[Study on the value of serum des-γ-carboxy prothrombin in predicting hepatocellular carcinoma recurrence after liver transplantation]

Objective: To explore the clinical value of serum des-γ-carboxy prothrombin (DCP) in predicting hepatocellular carcinoma recurrence after liver transplantation. Methods: A total of 115 cases with hepatocellular carcinoma who underwent liver transplantation in Zhongshan Hospital Affiliated to Fudan University from October 2016 to December 2018 were retrospectively analyzed. Receiver operating characteristic curve analysis, Mann-Whitney U test, Kaplan-Meier method, Log-Rank test, χ2 test, univariate and multivariate Cox regression analysis and other statistical methods were used to explore the value of DCP in predicting tumor recurrence after liver transplantation and its correlation with clinicopathological characteristics. Results: The preoperative serum DCP level in recurrent population after liver transplantation was significantly higher than that in non-recurrent population (P < 0.001). The optimal cut-off value of preoperative DCP for predicting recurrence was 200mAU/ml with the use of receiver operating characteristic curve. The sensitivity, specificity, Youden's index and the receiver operating characteristic curve was 87.90%, 57.30%, 0.452, and 0.726, respectively. Survival analysis results grouped by this cut-off value showed that patients with preoperative DCP ≥200mAU/ml had a higher probability of recurrence (P < 0.001). Further, subgroup survival analysis showed that patients with preoperative DCP≥200 mAU/ ml had a higher probability of recurrence than other cases of alpha-fetoprotein negative subgroup, cumulative tumor diameter ≤ 9 cm subgroup and Milan criteria subgroup (P < 0.05). Cox regression analysis showed that preoperative DCP≥200 mAU/ ml (P = 0.017) and cumulative tumor diameter > 9 cm (P = 0.014) was an independent risk factor for recurrence after liver transplantation. χ (2) test results showed that preoperative serum DCP level was correlated with gender, serum gamma glutamyltransferase level, serum alpha fetoprotein level, cumulative tumor diameter, vascular invasion, tumor differentiation and liver cancer transplant criteria (P < 0.05). Conclusion: Preoperative serum DCP can be used as a supplement to the existing liver cancer transplant criteria to predict hepatocellular carcinoma recurrence after liver transplantation. In addition, the accurate screening of patients with low risk of HCC recurrence after liver transplantation can improve the prognosis and efficacy of liver transplant patients.

[Overexpression of protein phosphatase 2 regulatory subunit B''α gene effect on proliferation and invasion of hepatoma cells]

Objective: To study the overexpression of protein phosphatase 2 regulatory subunit B''α gene effects on the proliferation and invasion of hepatoma cells. Methods: Immunohistochemistry method was used to analyze the expression of PPP2R3A in cancerous and paracancerous tissues. Hepatocellular carcinoma cell lines (Huh-7 and HepG2) with stably overexpressing PPP2R3A were constructed by lentiviral vector. Biological behavioral transition in hepatocellular carcinoma cell proliferation, cell cycle, apoptosis, invasion and metastasis were detected by cell counting kit-8 assay (CCK-8), flow cytometry, and transwell assay. A subcutaneous nude tumor mice model was constructed to validate the growth of hepatoma cells. Two independent sample t-tests were used to compare the groups. Results: The expression of PPP2R3A gene in human hepatocarcinoma tissues was higher than paracancerous tissues. The absorbance (A value) of hepatoma cells was increased (P < 0.05) after overexpression of PPP2R3A gene. The transition from G1-to-S phase was significantly increased i.e., the G1 phase of the cell cycle was reduced (Huh-7: t = 3.04, P = 0.0384; HepG2: t = 4.06, P = 0.0153), while the S phase was increased (Huh-7: t = 3.47, P = 0.0255; HepG2: t = 4.46, P = 0.0112). Early apoptotic rate was decreased (Huh-7: t = 7.34, P = 0.0018; HepG2: t = 4.06, P = 0.0153). The number of Huh-7 cells migrating to the lower chamber was increased (t = 3.18, P = 0.0334), and after the use of matrigel the number of cells reaching to the lower chamber was also increased (t = 2.84, P = 0.0464). The results of animal experiments showed that the subcutaneous tumor growth (t = 4.31, P = 0.0035) was significantly overexpressed in nude mice group. The results of Western blot showed that the expression of PARP and P53 protein in the spliced ​​forms decreased, while the accumulation of β-catenin protein in the liver cancer cells was increased. Conclusion: Overexpressed PPP2R3A gene may promote proliferation, migration and invasion ability, inhibit apoptosis, induce G1/S phase transition, and participate in the biological behavior of hepatoma cells.

Multidisciplinary treatment of a patient with necrotizing fasciitis caused by Staphylococcus aureus: A case report

BACKGROUND

Necrotizing fasciitis is a severe bacterial skin infection that spreads quickly and is characterized by extensive necrosis of the deep and superficial fascia resulting in the devascularization and necrosis of associated tissues. Because of high morbidity and mortality, accurate diagnosis and early treatment with adequate antibiotics and surgical intervention are vital. And timely identification and treatment of complications are necessary to improve survival of patient.

CASE SUMMARY

We report a case of necrotizing fasciitis caused by Staphylococcus aureus in a patient using high doses of glucocorticoid and suffering from secondary diabetes mellitus. He was admitted to our hospital due to redness and oedema of the lower limbs. After admission, necrotizing fasciitis caused by Staphylococcus aureus was considered, and he was discharged after B-ultrasound drainage and multiple surgical operations. In the process of treatment, multiple organ functions were damaged, but with the help of multi-disciplinary treatment, the patient got better finally.

CONCLUSION

The key to successful management of necrotizing fasciitis is an early and accurate diagnosis. The method of using vacuum sealing drainage in postoperative patients can keep the wound dry and clean, reduce infection rate, and promote wound healing. Interdisciplinary collaboration is a vital prerequisite for successful treatment.

A new MICA allele, MICA*007:07, characterized by cloning and sequencing

A new MICA allelic variant, MICA*007:07, was identified in an individual of Mongol ethnicity in the Inner Mongolia Autonomous Region, northern China. Following polymerase chain reaction-sequence-based typing (PCR-SBT), this new allele was further confirmed by cloning and sequencing. MICA*007:07 differs from MICA*007:01 by a synonymous mutation from G to A at the 2nd nucleotide position in exon 2. MICA*007:07 was linked to HLA-B*27:05.

Neutral particles pushed or pulled by laser pulses

Acceleration of neutral particles is of great importance in many areas, such as controlled chemical reactions, atomic nanofabrication, and atom optics. Recent experimental studies have shown that pulsed lasers can be used to push neutral Rydberg atoms forward [Nature 461, 1261 (2009)10.1038/nature08481; Nat. Photonics 6, 386 (2012)10.1038/nphoton.2012.87]. Our simulation shows that pulsed lasers can also be used to pull Rydberg atoms back toward a light source. In particular, we proposed a method of using two laser pulses on a neutral atom, then selective operations on the neutral atom (pushing or pulling) can be performed by adjusting the delay time between the two laser pulses.

Protein expression in dairy cows with and without subclinical hypocalcaemia

AIM

To determine differences in plasma proteomic profiles between healthy cows and those with subclinical hypocalcaemia within 12 hours after calving, and thereby explore the underlying biological mechanism of subclinical hypocalcaemia in dairy cows.

METHODS

Plasma samples were collected within 6 hours of calving from Holstein cows on a farm in Heilongjiang, China; 32 with subclinical hypocalcaemia (plasma calcium concentration 1.38-2.00 mmol/L and no clinical signs) and 59 control cows (plasma calcium concentration 2.10-2.8 mmol/L). Plasma samples were applied to weak cationic exchange protein chips for protein profiling by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS), and the data were analysed using the PBS-IIC system. The amplitude of peaks for the two groups were compared using the Wilcoxon sum-rank test, and the mass-to-charge ratio of the peaks that differed was used to identify peptide fragments using the Swiss-Prot protein database.

RESULTS

Seven peaks were identified in the subclinical hypocalcaemia group that differed from those of the control group (p<0.001), that represented six unique proteins. Expression of serum albumin, fibrinogen alpha chain, amyloid beta A4 proteins and neurosecretory protein VGF were increased, and expression of apolipoprotein A-II and serum amyloid A proteins were decreased in the subclinical hypocalcaemic cows compared with control cows.

CONCLUSION

Use of SELDI-TOF-MS technology can effectively identify differences in plasma protein expression patterns in cows with subclinical hypocalcaemia. Neurosecretory protein VGF and amyloid beta A4 protein might represent useful biomarkers for diagnosis of subclinical hypocalcaemia.

Biochip analysis of prostate cancer

Microarray expression analysis was used to forecast the roles of differentially co-expressed genes (DCG) and DCG and links in the pathogenesis of prostate cancer. In addition, we demonstrate that the relationship between transcriptional factors (TFs) and their targets can be considered a key factor in determining the difference between primary and metastatic prostate cancer. Regulatory impact factors were adopted to calculate the impact of TF. We identified 5 TFs and 29 target genes important in the transition between normal prostate and primary prostate cancer and 2 TFs and 7 target genes important in the transition between primary and metastatic prostate cancer. These results suggest that it may be possible to predict the clinical behavior of prostate cancer based on gene expression analysis.

Simulations of vacuum laser acceleration: hidden errors from particle's initial positions

Simulation of vacuum laser acceleration, because of its scheme's simplicity, attracts many people involved in. However, how to put the particle in the initial positions in the field has not been considered seriously in some such schemes. An inattentive choice of electron's initial conditions may lead to misleading results. Here we show that arbitrarily placing the particle within the laser field leads to an overestimation of its energy gain, and offer suggestions for selecting appropriate initial conditions.

Note: A sampling method for quantum random bit generation

In this note, we present a new sampling method for quantum random bit generation. The new method requires only one single-photon detector and does not measure the time slots of emitted photons. A binary random bit sequence obtained is independent on the time slot of the pulses and the precision of the measurement instrument. The effect of the exclusive-or operation for eliminating the bias in the raw sequences is also discussed.

Vacuum electron acceleration and bunch compression by a flat-top laser beam

The field intensity distribution and phase velocity characteristics of a flat-top laser beam are analyzed and discussed. The dynamics of electron acceleration in this kind of beam are investigated using three-dimensional test particle simulations. Compared with the standard (i.e., TEM(00) mode) Gaussian beam, a flat-top laser beam has a stronger longitudinal electric field and a larger diffraction angle. These characteristics make it easier for electrons to be trapped and accelerated by the beam. With a flat-top shape, the laser beam is also applicable to the acceleration of low energy electron and bunch compression.

Effect of sinomenine on gene expression of the IL-1β-activated human synovial sarcoma

Sinomenine is an alkaloid with pharmacological effects of anti-inflammation, anti-angiogenesis, anti-arthritis and immunosuppression. This study aimed to investigate the effect of sinomenine on gene expression of human synovial sarcoma cells (Hs701.T) activated by IL-1 beta. The proliferative effect of sinomenine was examined in the presence or absence of IL-1 beta by the [3H]-thymidine incorporation and MTT assay, respectively. Using DNA microarray technology and RT-PCR, the activating action of IL-1 beta and modulatory effect of sinomenine on Hs701.T were simultaneously determined. Results showed that IL-1 beta could stimulate the proliferation and gene expression of Hs701.T cells. Sinomenine could significantly inhibit proliferation of IL-1 beta-activated Hs701.T cells and suppress expression of 17 genes including IL-6, PlGF, Daxx, and HSP27. These genes were found to be important in tumor progression through the mediation of inflammation, cell adhesion, proliferation, apoptosis and angiogenesis. In conclusion, our study provides supplementary information for the further studies on the pharmacological effects of sinomenine acting on synovial sarcoma.

Effects of Si-Jun-Zi decoction polysaccharides on cell migration and gene expression in wounded rat intestinal epithelial cells

Si-Jun-Zi decoction (SJZD), a traditional Chinese herbal prescription, has been used clinically for treating patients with disorders of the digestive system. Previous studies indicated that the polysaccharides of SJZD (SJZPS) are the active components contributing towards its pharmacological effects in improving gastrointestinal function and immunity. However, the protective and restitutive effects on intestinal epithelial cells remain unknown. In the present study, SJZPS were first extracted and chemically characterized. Then their stimulatory and restitutive effects on intestinal epithelial cells (IEC-6 cells) were elicited by different in vitro models including migration of wounded IEC-6 cells and cell proliferation. Results indicated that SJZPS not only protects the cells against the harmful impairment of indomethacin but also enhances re-epithelialization of a wounded monolayer at an optimal dose of 100 mug/ml at 24 h incubation. To elucidate the modulatory effect of SJZPS on wounded IEC-6 cells at the molecular level, an oligonucleotide microarray was employed to study differential gene expression of SJZPS-treated IEC-6 cells and the candidate genes were validated by RT-PCR. There was increased expression of genes coding for ion channels and transporters, which are critical to cell migration and restoration of wounded intestinal cells, suggesting a possible mechanism for re-epithelialization. In conclusion, our data show for the first time that SJZPS can enhance intestinal restitution and protect against indomethacin-induced damage of intestinal epithelial cells. These findings provide new insight into the mechanism of action of a traditional Chinese herbal prescription, SJZD, in intestinal wound restitution.

Subluminous phase velocity of a focused laser beam and vacuum laser acceleration

It has been found that for a focused laser beam propagating in free space, there exists, surrounding the laser beam axis, a subluminous wave phase velocity region. Relativistic electrons injected into this region can be trapped in the acceleration phase and remain in phase with the laser field for sufficiently long times, thereby receiving considerable energy from the field. Optics placed near the laser focus are not necessary, thus allowing high intensities and large energy gains. Important features of this process are examined via test particle simulations. The resulting energy gains are in agreement with theoretical estimates based on acceleration by the axial laser field.

[Analytic solution and experimental verification of pressure control function of the sealed module of manned space vehicle]

OBJECTIVE

The analytic solution of the overall pressure and oxygen partial pressure in the scaled module of manned space vehicle was deduced, it can be used by ECLSS overall engineering designer to predict the pressure control parameters when space flight or ground test is operating.

METHOD

According to different gas supply situations and the role of pressure control zone prescribed by ECLSS, the flight duration was divided into several segments under the role of pressure control zone, and the differential equations were solved.

RESULT

The analytic solutions of the total pressure and partial pressure of oxygen were obtained, and the theoretical curve corresponds well to the test value.

CONCLUSION

The analytic solutions obtained were valid, and satisfied the requirement of engineering accuracy.

[Principle demonstration of nutrient delivery system in a space vegetable planting prototype facility]

Objective. To develop a nutrient delivery system for space vegetable planting prototype facility to be used in future space station, and to preliminarily testify its feasibility through ground-based demonstration experiments. Method. A nutrient delivery system in a space vegetable planting prototype facility was designed and fabricated, and ground based demonstration experiments of plant cultivation were conducted. Result. Nutrient could be steadily delivered to plant cultivation matrixes through capillary action, water content of planting matrixes could be controlled automatically and maintained constant, and the planted material lettuce showed basically normal morphology and color. Conclusion. The nutrient delivery system in a space vegetable planting prototype facility could basically meet the requirements for plant nutrient delivery under space microgravity environmental condition.

Induction of apoptosis during development of hypertensive nephrosclerosis

BACKGROUND

As the biology of programmed cell death, or apoptosis, is clarified, a role for this process in the pathophysiology of organ dysfunction and fibrosis has been hypothesized. Hypertensive nephrosclerosis represents an important cause of end-stage renal disease. One model of the progressive, noninflammatory, sclerotic renal lesion of hypertension is the Dahl/Rapp salt-sensitive rat, which was examined in this study.

METHODS

Male, Dahl/Rapp salt-sensitive (SS) and Sprague-Dawley rats were placed on either 0.3 or 8.0% NaCl diets for three weeks. Blood pressure was determined, and the kidneys were harvested for histochemical analysis and to obtain total RNA for RNase protection assays and total protein for Western blotting.

RESULTS

An increase in apoptosis in the glomerular and tubular compartments was observed only in kidneys of SS rats on the high-salt diet. These findings occurred at a time when renal function was markedly impaired and irreversible changes in renal morphology developed. Temporally associated with this increase in apoptosis was augmented expression of pro-apoptotic molecules that included Fas, Bax, and Bcl-XS.

CONCLUSIONS

The inappropriate shift in expression of proteins that facilitate apoptosis in the nephron, along with ongoing cell death that manifested at a time when renal function was deteriorating, supported an important role for this process in development of hypertensive nephrosclerosis.

[Development of an experimental facility for waste treatment by microorganism]

Objective. To construct an experimental facility for microorganism waste processing, which will be used to recover plant nutrient liquids from plant inedible biomass essential for growth and development of plants. Method. After technical parameters and performance requirements were defined, plan demonstration, drawing design, fabrication, debug and preliminary plant inedible residue-biodegradation tests of microorganisms were conducted. Result. The temperature, stirring speed and gas-supplying flow of bioreactor of the facility were controlled automatically, as well as the pH and dissolved oxygen concentration were measured automatically and controlled manually, testifying that its performance reached the requirements of predetermined technical indexes. The 15-d test showed that the facility ran smoothly, its above-mentioned parameters could be measured and controlled precisely, and the biodegradation rate of lettuce's inedible biomass approximately attained 90%. Conclusion. The facility holding reasonable technical indexes, smooth and dependable performances, is capable of being utilized to biodegrade plant inedible biomass. It is expected that if the above-mentioned parameter combinations are optimized further, the results should be better.

Conditions for electron capture by an ultraintense stationary laser beam

We present in this paper a quantitative study of an effect, in which a low-energy free electron is captured and violently accelerated to GeV final kinetic energy by a stationary extra-high-intensity laser beam (Q0 identical witheE/m(e)omegac greater, similar100). The conditions under which this phenomenon can occur, such as the momentum range, incident angle of the incoming electron, the waist width of the laser beam, etc., have been investigated in detail.

[Development of a ground-based experimental facility for space cultivation of higher plant]

A ground-based experimental facility was developed for conducting initial ground-based simulation study of Controlled Ecological Life Support System (CELSS). The facility is composed of a main chamber, O2 and CO2 composition control subsystems, plant cultivation subsystem and whole data management subsystem. The growth room, being composed of a inner wall of mirror-face stainless steel, holds a volume of 1.8 m3 and a growing area of 1.2 m2; electronic fluorescent lamps were used as lighting sources and polyvinyl formal was used for root matrixes; the environmental parameters of the growing room such as temperature, relative humidity, O2 concentration, CO2 concentration, lighting period and irradiance intensity and the nutrient parameters such as pH, electrical conductivity, dissolved oxygen concentration, liquid level of nutrient storage tank and flow rate of nutrient were all controlled automatically; all of the above-mentioned parameters can be inspected, collected, stored and printed regularly and dynamically. The results of a combined debugging and preliminary plant cultivation verified that the technical target of the facility had reached its initial design requirements, it can be used to conduct ground-based simulation studies of space cultivation of higher plants.

Peritransplant tolerance induction in macaques: early events reflecting the unique synergy between immunotoxin and deoxyspergualin

BACKGROUND

Day of transplant T cell depletion with anti-CD3 immunotoxin or F(Ab)2 immunotoxin induces stable tolerance to renal allografts in rhesus monkeys given 15-deoxyspergualin (DSG), a NF-kappaB inhibitor that suppresses proinflammatory cytokine (PC) production. Because PC and NF-kappaB are involved in dendritic cell (DC) maturation, we asked if impaired DC maturation and Th2-type cytokine deviation might be related to the synergistic effect of DSG in this novel model.

METHODS

Immunosuppression was initiated 4 hr before transplanting a major histocompatibility complex mismatched renal allograft. Some groups received a supplemental 5-day course of cyclosporine A or DSG or a 15-day course of DSG. Peripheral lymph nodes were sequentially examined for presence of mature DC. In vitro effects of DSG on PC-induced maturation of DC were also examined.

RESULTS

Allografts survived without rejection in 87% of recipients given immunotoxin or F(Ab)2 immunotoxin with DSG x 15 days, in 50% with DSG x 5 days, and 0% with cyclosporine A. The longest DSG survivors are >1000 days with normal graft function and tolerance validated, including acceptance of challenge second donor kidneys without treatment. DSG-treated recipients were unique in developing polarized Th2-type plasma cytokines. In DSG recipients, mature DC were significantly reduced in day +5 lymph node biopsies, with complete repopulation by 30 days. In vitro studies verified an inhibitory effect of DSG on DC maturation.

CONCLUSIONS

The study suggests DSG arrests DC maturation. The unusual synergy of immunotoxin and DSG apparently involves coincidental reduction in lymph node T cell mass and mature DC, a transient circumstance favoring development of stable tolerance.

High-intensity laser-induced electron acceleration in vacuum

In this paper, an approximate pulsed-laser-beam solution of Maxwell's equation in vacuum is derived. Then with the numerical simulation method, electron acceleration induced by high-intensity [Q(0)=eE(0)/(m(e)omega c)=3] lasers is discussed in connection with the recent experiment of Malka et al. It is found that the maximum energy gain and the relationship between the final energy and the scattering angle can be well reproduced, but the polarization effect of electron-laser interactions is not very prominent. These results show that the ponderomotive potential model is still applicable, which means that the stimulated Compton scattering is the main fundamental mechanism responsible for the electron acceleration at this laser intensity.

DR non-B1 mismatches influence allogeneic MLR-induced TH1- or TH2-like cytokine responses in rhesus monkeys

Human and nonhuman primates have multiple DR B1 and non-B1 alleles. However, the role of mismatched DR non-B1 alleles in primary alloimmune responses is not well understood. Macaques, which share close DNA homologies with human MHC genes and have a high number of beta-chain genes in the DR subregion, are preeminent preclinical models for immunologic studies of transplant tolerance and immunosuppression. In this study, we examined the effect of allogeneic MHC Class II DRB mismatches in Th1- and Th2-like cytokine responses elicited in one-way MLR cultures in rhesus macaques. An ELISPOT method was used to estimate cytokine secretion at the single cell level. Molecular typing for DRB1 and DR non-B1 alleles was performed by a moderate-high resolution PCR-SSP method using a panel of 55 primer pairs covering 74 DRB alleles and clusters. Of 35 unrelated combinations, 66% had multiple (> or = 2) allelic MM at DRB1 and DR non-B1 with no significant correlation between numbers of DRB1 and DR non-B1 mismatches. Pairs with 1 or 0 MM were assigned to a mono/null MM group to obtain sufficient numbers for statistical analysis. The pairs differing by multiple vs. mono/null DRB1 MM showed no significant difference in cytokine prevalence (P = 0.69). In contrast, high IFN-gamma/ IL4 SFC ratios were noted in pairs with multiple vs. mono/null DR non-B1 MM (p = 0.0009). IFN-gamma/IL-10 spot forming cell (SFC) ratios were consistent with IFN-gamma/IL-4 SFC ratios (r = 0.98). Multiple DR non-B1 mismatches showed a trend towards higher MLR proliferative responses, although the stimulation index did not reflect the dominant cytokine response. These observations suggest a bias towards Th1-like cytokine production under allostimulation with multiple DR non-B1 gene products. Further study of the primary structure of DR non-B1 determinants may be helpful in understanding the fine molecular mechanisms governing the regulation of cytokine profiles during allostimulation in primates.

Peritransplant tolerance induction with anti-CD3-immunotoxin: a matter of proinflammatory cytokine control

BACKGROUND

Tolerance is gaining momentum as an approach to reduce lifelong immunosuppressive therapy while improving transplant longevity. Anti-CD3 immunotoxin (IT), FN18-CRM9, has potential to induce tolerance owing to its exceptional ability to deplete sessile lymph node T cells. However, if initiated at the time of transplantation, alpha-CD3-IT alone elicits a proinflammatory cytokine response, precluding establishment of tolerance.

METHODS

Four groups of rhesus monkeys received kidney allografts and immunosuppression. Three groups received alpha-CD3-IT alone or alpha-CD3-IT supplemented with 15-deoxyspergualin (DSG) and/or methylprednisolone (MP). One group received alpha-CD3-monoclonal antibody with DSG and MP. Cytokines were measured by enzyme-linked immunosorbent assay.

RESULTS

Supplementing peritransplant alpha-CD3-IT treatment with a brief course of DSG and MP promoted rejection-free kidney allograft acceptance in 75% of macaques followed for up to 550 days. Among those given alpha-CD3-IT alone or with MP, none were long-term survivors. Tolerance developed after alpha-CD3-IT, DSG, and MP treatment, but not when the unconjugated a-CD3 monoclonal antibody was substituted for IT. Systemic production of proinflammatory cytokines interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha induced after peritransplant alpha-CD3-IT was prevented only in animals given DSG. Despite high levels of interleukin (IL)-12 in the first month after transplant, tolerant recipients exhibited IL-12 resistance, as evidenced by baseline plasma levels of IFN-gamma but elevated IL-4. DSG was shown to inhibit IL-12-driven IFN-gamma production by a mechanism associated with inhibition of nuclear factor kappa-B.

CONCLUSIONS

In this model, peritransplant induction of tolerance is promoted by efficient elimination of sessile lymph node T cells and control of the proinflammatory IFN-gamma response by a mechanism that appears to involve resistance to IL-12.

Preclinical studies of allograft tolerance in rhesus monkeys: a novel anti-CD3-immunotoxin given peritransplant with donor bone marrow induces operational tolerance to kidney allografts

A major challenge in clinical transplantation today is to design a practical and effective protocol for tolerance induction compatible with cadaver organ transplantation. A preclinical rhesus monkey kidney allograft model using immediate peritransplant anti-CD3 immunotoxin (anti-CD3-IT) and donor bone marrow (DBM) is shown here to induce operational tolerance with prolonged graft survival in the absence of chronic immunosuppressive drugs. Bone marrow harvested from the kidney donor was depleted of mature alloantigen-presenting cells and T cells by removing DR(bright) cells and CD3(bright) cells, respectively. In outbred, major histocompatibility complex-incompatible donor-recipient pairs with high pretransplant mixed lymphocyte response and cytotoxic T lymphocyte precursor activity, four of six allografts survived for periods of 120 days to >1.5 years. Graft acceptance after peritransplant treatment followed robust elimination of both peripheral blood T cells and lymph node T cells. In most recipients given anti-CD3-IT and DBM infusion, anti-donor immunoglobulin G responses were completely inhibited. Microchimerism was observed in all recipients studied, including those not given DBM, but levels of microchimerism did not correlate with graft survival. Anti-CD3-IT induction in combination with modified DBM protocols such as the depletion of mature T cells and DR(bright) antigen-presenting cells may offer new opportunities to improve clinical tolerance protocols beyond those attempted in the clinic to date. Overall, these results with anti-CD3-IT show promise for development of cadaver transplant tolerance induction.

[NK cell activity in patients with kidney insufficiency]

Natural killer cell (NKC) plays an important role in anti-cancer, anti-virus and the regulation of immune reaction in human body. NK cell activities from the peripheral blood were determined with 51Cr release method from the human erythroleukemia cell line K562 in 61 patients, who were selected in the light of the standard of deficiency syndrome in TCM with insufficiency of the Kidney in which 12 kinds of diseases in western medicine were included, and 60 healthy subjects as control group. The patients with insufficiency of the Kidney showed significantly decrease in NK cell activity compared to the control group (25.29 +/- 10.20 vs 56.27 +/- 16.72, P less than 0.001). NK cell activities in 20 out of 60 patients, with deficiency of Kidney-Yang, were lower than 21 with deficiency or Kidney-Yin (19.38 +/- 7.44 vs 26.60 +/- 8.95, P less than 0.01) and 20 with deficiency of Kidney-Qi (19.38 +/- 7.44 vs 29.38 +/- 11.30, P less than 0.01), respectively, while there was no difference between the deficiency of Kidney-Qi (P greater than 0.05). The authors also found that NK cell activities of healthy subjects were strongly inhibited by plasma from 43 out of 61 patients. These results suggested that decreased NK cell activity is one of the common characters in patients with insufficiency of the Kidney in TCM and there are some inhibitory substances against NK cell activity in plasma of ones. The fact that NK cell activity of patients with deficiency of Kidney-Yang was the lowest among three kinds patients with insufficiency of the Kidney.(ABSTRACT TRUNCATED AT 250 WORDS)