Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

The Relationship between Christian Religiosity and Adolescent Substance Use in China

Abundant research has shown that Christian religiosity inhibits adolescent substance use, especially in communities where most of the population shares the same religious values and beliefs. Due to the lack of empirical research, it is unclear if Christian religiosity has the same inhibitory influence in predominantly secular and religiously diverse societies. This study aims to bridge this gap and thereby improve our understanding of the relationship between Christian religiosity and delinquent behavior in different cultural contexts. Through the analysis of survey data collected from a large probability sample of adolescents in China's special administrative region of Macau, this study found a strong inverse relationship between Christian religiosity and adolescent substance use, despite the predominantly secular nature of Macau society. In contrast, religious commitment among non-Christian youths showed no relationship with substance use. The theoretical and practical implications of the findings are discussed.

The Changing Patterns and Correlates of Adolescent Substance Use in China's Special Administrative Region of Macau

Most of the research on adolescent substance use is from either the U.S, Europe, or other non-Eastern countries, but very little attention is paid to that in the Greater China Region. As a special administrative region of China, Macau is known for its gambling industry, its proximity to the Golden Triangle, and its lenient drug laws, all of which can be conducive to high-level drug use in the population, including its adolescents. Yet, the extent and patterns of adolescent substance use in Macau are not well understood. Using the data collected from two large representative samples of secondary school students in 2014 and 2018, this study provided population-based estimates of the prevalence rates of lifetime and past 30-day substance use among Macau adolescents in the two separate survey years. By comparing the two sets of estimates, it established the patterns of changes in cigarette smoking, alcohol use, and illicit drug use among adolescents in Macau during the period. Additionally, through the analysis of the data in the latest year, it identified risk factors for adolescent substance use in the special administrative region. Among the key results, the rates of cigarette smoking and illicit drug use were low to moderate while the rates of alcohol use were relatively high; cigarette smoking decreased during the period, but alcohol use and illicit drug use remained stable; Macau adolescents shared similar risk factors for substance use with adolescents elsewhere, but unique circumstances might exist to influence their alcohol consumption.

In the Shadow of the Casinos: The Relationship between Religion and Health in Macau

Considerable research has shown that religion operates as a protective factor for one's health. However, there is still a lack of understanding of the mechanisms by which religion is linked to individual health and wellbeing, especially in predominantly secular societies. This study tried to address this gap by developing a theoretical model to examine how religiosity is related to life satisfaction and health perception in a non-Western culture. Macau, a Portuguese colony until 1999, remains a diversified culture because of its intermixed historical background from the East and the West. Through structural equation modeling, the analysis of data collected from a representative sample of Macau residents, using a multistage stratified sampling procedure, indicated a positive link between religiosity and health. Moreover, altruism and prejudice mediated a portion of the relationship between religiosity and health. Additionally, our results demonstrated that Macau residents who were more religious had a higher level of altruism and a lower level of prejudice. The link between religion and prejudice in Macau differs from that of many other cultures, indicating that the effect of religion on prejudice varies by cultural context. In sum, our study showed that even in the shadow of glittering casinos, religion is positively related to health.

[Integration of clinical significance and statistical significance on clinical study results categorization: a Meta-epidemiology study]

Objective: Statistical significance plays an important role in the interpretation of clinical trial results. However, on the basis of obtaining statistical significance, the assessment of clinical significance is often neglected. This study attempted to propose a simple and unambiguous new classification method for study results, focusing on studies with statistical positive findings to evaluate whether the results have clinical significance. Methods: Our study subjects were the clinical studies in 2019 ACC and ESC annual meetings. Meta-epidemiology methods were used to extract the characteristic variable from each study. The primary evaluation indicators included target effect-size and observed effect-size. Based on the difference between the two indicators, the studies that had statistical significance were subdivided to identify studies with possible insufficient clinical significance; Furthermore, the theoretical threshold based on power analysis was proposed, which was used as the basis for the interpretation of study results. Results: There were 12 clinical studies included in the final analysis. All of them were published on top journals. Those studies had relative high quality on both study design and reporting. The correlation coefficient between the observed and target effect-size was 0.892. Among the 7 studies with statistical significance, two of them were classified as insufficient clinical significance. The counts was 1 (1/3) and 1 (1/4) for the studies reported in ACC and ESC respectively. Conclusions: The achievement of clinical significance is critical even in the study with positive results. This paper proposes a new classification standard that combines clinical significance with statistical significance and further suggests a method to evaluate the reliability of clinical study results in order to assist researchers in identifying potential risks caused by insufficient clinical significance, and provide some reference and help for the reasonable interpretation of clinical study results.

Coercive Parenting and Adolescent Developmental Outcomes: The Moderating Effects of Empathic Concern and Perception of Social Rejection

Previous studies have identified coercive parenting as a prevalent parenting style in Chinese society. They suggested that this style of parenting could promote prosocial behavior and school commitment when combined with close monitoring and proper training, but it could also undermine mental health. This study critically examines these claims. Based on the existing theory and research, it is predicted that the influences of coercive parenting on adolescent development vary according to adolescent personal attributes including empathic concern and perception of social rejection. Through the analysis of two-wave survey data collected from a probability sample of 1085 Chinese adolescents, this study found that adolescents with higher levels of empathic concern and perceived social rejection reported less delinquency and stronger school commitment than their peers with lower levels of such attributes, when coercive parenting was low to moderate. However, under the condition of excessive coercive control, these adolescents demonstrated more delinquency and weaker school commitment. Empathic concern and perception of social rejection, on the other hand, played no or limited role in moderating the relationship between coercive parenting and depression. These results suggest that the influences of coercive parenting are dynamic and are subject to change as they interact with adolescent personal characteristics across different developmental domains.

Analysis of Driver-Passenger Relationship and Restoration of Accident Process Based on 3D Laser Scanning Technology

Abstract

Objective To discuss the application of 3D laser scanner and computer technology in restoration of the accident scene and reconstruction of the accident process, as well as identification of the driver-passenger relationship. Methods The scene of a traffic accident, the accident vehicle and the vehicle of the same type as accident vehicle were scanned using 3D laser scanner. The accident scene, traces and accident vehicle were integrated using computer technology to restore the accident scene, and the accident process was reconstructed and analyzed by combining the characteristics of the body injuries. Results By restoring the accident scene and reconstructing the accident process with 3D laser scanner, it was determined that Wu was in the driving seat at the time of the accident. Conclusion It is more objective and scientific to use 3D laser scanning technology to restore the accident scene, reconstruct the accident process and analyze the moving track of the driver and passengers in the vehicle. It will help to improve the accuracy of forensic identification of road traffic accidents.

A Longitudinal Study of Authoritative Parenting, Juvenile Delinquency and Crime Victimization among Chinese Adolescents

Empirical research on the relationship between authoritative parenting and crime victimization has been sparse, although this style of parenting has been identified as an effective parenting practice for inhibiting offending behavior among children and adolescents. The current research aims at filling this gap by examining the influences of authoritative parenting on juvenile delinquency and crime victimization, as well as the mechanisms connecting the processes. Using two-wave survey data collected from a probability sample of 1066 Chinese adolescents, the current study employed a structural equation modeling analysis to test the relationships. The results indicated that authoritative parenting negatively predicted juvenile delinquency and crime victimization. Further, adolescent mental health problems and delinquent peer association partially mediated the influence of authoritative parenting on delinquency, while adolescent mental health problems, delinquent peer association, and juvenile delinquency fully mediated the relationship between authoritative parenting and crime victimization. The results also showed that juvenile delinquency positively predicted future crime victimization. Overall, this study demonstrated that authoritative parenting operated as a protective factor against juvenile delinquency and crime victimization.

The Spillover Mechanisms Linking Family Conflicts and Juvenile Delinquency Among Chinese Adolescents

The mechanisms through which conflicting parental relationship and parenting practices influence adolescent antisocial behavior have not been adequately understood. To bring more understanding to the mechanisms, this study investigates how marital discord interrelates with interparental inconsistency in parenting practices, and how these family conditions influence juvenile delinquency through their spillover effects on mental health problems, parental attachment and delinquent peer association among Chinese adolescents. Findings obtained from a structural equation modeling analysis of survey data collected from a probability sample of 2,496 adolescents (mean age = 15.16 years) are generally consistent with the spillover effect hypothesis. The results demonstrate that mental health problems, parental attachment, and delinquent peer association operate as critical mediators linking marital discord and interparental inconsistency to juvenile delinquency.

P4629Long-term outcomes in patients with ST-segment elevation myocardial infarction according to modalities of reperfusion therapy: data from china acute myocardial infarction (CAMI) registry

Background

Although primary percutaneous coronary intervention (pPCI) is the optimal reperfusion method for ST-segment elevation myocardial infarction (STEMI), it remains difficult to implement in many areas. Some STEMI patients have to accept fibrinolytic therapy and no reperfusion therapy instead.

Purpose

The aim of this study was to describe the impact of reperfusion therapy on the long-term outcomes of STEMI patients in China.

Methods

Using data from the China Acute Myocardial Infarction (CAMI) registry, we analyzed the 2-year outcomes of 18,075 STEMI patients symptom onset within 7 days from January 2013 to September 2014 according to the type of reperfusion therapy. The primary endpoint was a composite of major adverse cardiovascular event (MACE), defined as all-cause mortality, myocardial infarction or stroke.

Results

7798 (43%) were treated with pPCI and 1798 (10%) underwent fibrinolysis; 8479 (47%) did not receive any reperfusion. The 2-year MACE was 9.6% following pPCI, 15.7% following fibrinolysis, and 21.5% for patients without reperfusion therapy (P<0.0001). Adjusted hazard ratios for 2-year MACE were 0.71 (95% confidence interval [CI] 0.65–0.78, P<0.0001) for pPCI versus no reperfusion and 0.92 (95% CI 0.82–1.03, P=0.16) for fibrinolysis versus no reperfusion. Compared with patients without reperfusion, fibrinolysis only showed benefit in patients presented within 3 hours of symptom onset (HR 0.70, 95% CI 0.57–0.85, P=0.0005), whereas pPCI was associated with significantly decreased 2-year MACE rate in patients presented within 3 hours (HR 0.53, 95% CI 0.44–0.64, P<0.0001), 3–6 hours (HR 0.60, 95% CI 0.51–0.71, P<0.0001) and >6 hours (HR 0.86, 95% CI 0.76–0.97, P=0.01) of symptom onset.

Adjusted cumulative MACE rate

Conclusions

In a real-world setting, early reperfusion is the optimal strategy for STEMI. Fibrinolysis was not associated with better outcome in STEMI patients admitted >3 hours of symptom onset in Chinese real world setting.

Acknowledgement/Funding

Ministry of Science and Technology of China (Grant No. 2011BAI11B02)

[Prognosis factors analysis of 56 cases of non-Hodgkin's lymphoma originating from the nasopharynx]

Objective:To investigate the prognosis of non-Hodgkin's lymphoma originating from the nasopharynx.Method:The clinical data of 56 patients with a primary diagnosis of non-Hodgkin's lymphoma originating from the nasopharynx treated between January 2010 and December 2015 were studied.The association between clinical parameters and survival rate was evaluated by Kaplan-Meier method and Cox regression model.Result:The 1,3,5-year overall survival were 91.1%, 73.1%,and 49.6% respectively.Single factor analysis displayed that age,Ann-Arbor staging,iactate dehydrogenase,combined with B symptoms at the time of diagnosis,international prognostic index and the expression level of Ki-67 were related to the prognosis factors.Multivariate analysis showed that the international prognostic index greater than or equal to 2 points and the positive rate of Ki-67 greater than or equal to 60% were the independent risk factors for the prognosis of non-Hodgkin's lymphoma originating from the nasopharynx.Conclusion:International prognostic index and the expression level of Ki-67 may be independent prognostic factors for non-Hodgkin's lymphoma originating from the nasopharynx.

[A retrospective analysis of the efficacy and safety of imatinib in children with chronic myeloid leukemia during chronic phase]

Objective: To evaluate the efficacy and safety of imatinib in the treatment of newly diagnosed chronic myeloid leukemia during chronic phase (CML-CP) in children and to analyze the difference of the efficacy and safety between imported original imatinib (Gleevec) and domestic generic imatinib (Xinwei). Methods: Clinical data of 35 children with newly diagnosed CML-CP in Beijing Children's Hospital from January 2014 to January 2018 were collected, among which 15 cases were treated with the imported original imatinib (original drug group) and 20 cases were treated with the domestic generic imatinib (generic drug group). The hematological, cytogenetic and molecular reactions and safety of the treatments were monitored at months 3, 6 and 12. Chi square test or rank sum test was used for the comparison between two groups. Results: A total of 35 cases were treated for over 3 months, 31 cases were treated for over 6 months and 25 cases were treated for over 12 months. At 3 months, main cytogenetic response was obtained in 15 (100%) cases in the original drug group and 16 (80%) cases in the generic drug group respectively (χ(2)=3.387, P=0.119). At 6 months, complete cytogenetic response was obtained in 12 (80%) cases in the original drug group and 10 (63%) cases in the generic drug group (χ(2)=1.435, P=0.390). At 12 months, BCR-ABL(IS) ≤ 0.1% was obtained in 11 (92%) cases in the original drug group and 10 (77%) cases in the generic drug group (χ(2)=1.009, P=0.593). There was no significant difference at all stages (all P>0.05). Hematologic toxicity occurred in 7(20%) cases. The non-hematologic adverse reactions include nausea in 8 (23%) cases, pain in 8 (23%) cases, edema in 6 (17%) cases, emesis in 2 (6%) cases, fever in 2 (6%) cases, weakness in 1 (3%) case, rash in 1 (3%) case. The adverse reactions were easy to control and no drug toxicity related deaths occurred. There was no significant difference in the adverse reactions between original drug group and generic drug group (P>0.05). Conclusions: Imatinib had a good efficacy and safety in the early treatment of newly diagnosed CML-CP in children. The efficacy and safety of generic imatinib is similar to that of imported imatinib.

[CD23 on B cells determines Breg-facilitated IL-10 secretion as well as activation of T cells]

Objective:To explore whether or not the IL-10 mediated by Bregs modulate the secreting T cells activation by the anti-CD23 antibody, to find a new target for the treatment of allergic rhinitis. Method:The rat model of allergic rhinitis was established. Anti-CD23 antibody was used to observe the behavioral changes, passive skin allergen test, enzyme-linked immunosorbent assay, hematoxylin and eosin staining, immunofluorescence and flow cytometry serological indicators, systemic and nasal mucosa. Result:Compared with the blank control group, allergic rhinitis group rats sneezing, flexible nose, runny nose, subcutaneous mass increases;The levels of IL-10, IFN-γ and Bregs in blood decreased, the levels of IL-4, CD23+ B cells and CD4+ T cells increased;Nasal mucosa CD23 fluorescence intensity increased, CD19 and IL-10 fluorescence intensity decreased. Compared with the allergic rhinitis group, the number of sneezing, the frequency of nasal flexion, the symptoms of runny nose and the subcutaneous mass in the antibody intervention group were significantly improved;The levels of IL-10 in the blood, IFN-γ, the percentage of Bregs cells in whole blood increased, the levels of IL-4, CD23+ B cells and CD4+ T cells decreased;Nasal mucosa CD23 fluorescence intensity decreased, CD19 and IL-10 fluorescence intensity increased. There is little difference between the two routes of administration. Conclusion:The enhanced expression of CD23 on B cells is involved in the development of allergic rhinitis. The anti-CD23 antibody may control the symptoms and signs of allergic rhinitis. There is no significant difference between subcutaneous administration and improved nasal-drip way. As the preferred method of anti-CD23 antibody application, anti-CD23 is expected to become a new method to control and treat allergic rhinitis. Anti-CD23 antibodies can exert a therapeutic effect by T cell activation,which rely on the Bregs-mediated secretion of IL-10.

[Experience on postoperative complications of laparoscopic pancreaticoduodenectomy]

Objective: To summarize the incidence and characteristics of postoperative complications after laparoscopic pancreaticoduodenectomy(LPD), and to share our experience on management of complications. Methods: The clinical data of 320 LPD performed by a single team in Sir Run Run Shaw Hospital and Zhejiang Provincial People's Hospital between September 2012 and September 2017 were retrospectively analyzed, among which there were 196 males and 124 females with age of (60.2±11.6) years old.There were 306 patients who underwent standard LPD, and 14 patients who underwent extended LPD. The patients were divided into 2 groups of former 160 LPD and later 160 LPD according to the time order. By analyzing the differences of clinical outcomes between the two groups, especially focusing on the incidence of postoperative complications.The experience on management of complications was concluded. The prior surgical history of latter group was significantly higher than the former group(30.0%(48/160)vs. 18.8%(30/160), χ(2)=5.49, P=0.019), and the rest of baseline characteristics remained the comparable (P>0.05). For resectable lesions, LPD was performed by "No back" approach, following the principle of "From distal to cephalad, from ventral to dorsal, and from left to right" . As for the borderline resectable patients, LPD was performed by "Easy first" strategy. Student t test, χ(2) test or Fisher test was used to analyzed the data between the two groups respectively. Results: Of 320 LPD patients, 306 cases underwent standard LPD, 14 cases underwent LPD with resection of other organs.There were 278 LPD cases who followed "No back" approach, and 42 cases who followed "Easy first" strategy because of difficulty in creating the retro-pancreatic tunnel. And the overall morbidity was 32.2%(103/320) with reoperation rate of 5.3%(17/320). The perioperative mortality was 0.6%(2/320). The operation time of latter group was ((346.6±48.8)minutes), which was shorter than that of former group((358.0±54.4)minutes)(t=1.97, P=0.048). The blood loss of former and latter group remained comparable((207.9±135.8)ml vs.(189.6±121.4)ml, P=0.205). However, in subgroup analysis, the patients with blood loss less <200 ml of latter group decreased significantly from 59.4%(95/160) to 47.5%(76/160)(χ(2)=4.53, P=0.033). The overall morbidity of latter group was 28.8%(46/160), indicated a decrease from 35.6%(57/160) of former group without significant difference(P=0.188). Moreover, Grade A/B/C pancreatic fistula rate, Grade A/C bile leakage rate, Grade B/C postoperative hemorrhage rate of the later group tended to decrease, although they also didn't reach a significant difference. However, the abdominal infection rate decreased significantly(χ(2)=3.93, P=0.047). The length of hospital stay remained comparable(P=0.156). Conclusions: The most common complications after LPD were postoperative hemorrhage and pancreatic fistula. With specialized team and accumulated experience, the morbidity can decrease progressively by analyzing the leading cause and improving the technical skills.

Effects of ginsenoside Rg1 on glucose metabolism and liver injury in streptozotocin-induced type 2 diabetic rats

Type 2 diabetes mellitus (T2-DM) is a chronic metabolic disorder characterized by high blood glucose levels. T2-DM patients suffer from many complications, such as diabetic fatty liver and diabetic nephropathy. The liver, the pivotal organ involved in both glucose and lipid metabolism, is primarily damaged in T2-DM patients, especially in those with high levels of blood lipid. In this study, the hepatoprotective activity of ginsenoside Rg1 was investigated in a T2-DM rat model. The results revealed a potent hepatoprotective effect of ginsenoside Rg1. This effect was primarily mediated by the antiapoptotic effect, inhibition of JNK activity, and suppression of inflammation after ginsenoside Rg1 treatment. Ginsenoside Rg1 also lowered the blood glucose level and insulin resistance index in T2-DM rats. Moreover, the blood lipid profile (total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels) and liver function (aspartate transaminase and alanine transaminase levels) improved after ginsenoside Rg1 treatment. The aforementioned hepatoprotective effects of ginsenoside Rg1 in the T2-DM rat model suggests its clinical potential as an adjuvant drug for T2-DM therapy, especially for T2-DM patients with fatty liver disease.

The Gendered Effects of Adult Social Bonds on the Criminal Activities of Probationers

The central question addressed in this article is whether the effects of adult social bonds vary by gender. Contrary to the social control theory, it is argued here that male offenders and female offenders do not respond to the controlling effect of adult social bonds in the same way, because they possess different levels of antisocial tendencies. The authors constructed a two-level hierarchical model using monthly data collected from 125 probationers to evaluate the effects of social bonds and drug use on criminal activities. The findings showed complex patterns. For male probationers, social bonds operated as a strong inhibitor of crime while drug use acted as a moderate facilitator of criminal activities. For female probationers, both social bonds and drug use operated as strong facilitators of criminal behavior. The results support the argument that adult social bonds affect male crime and female crime differently. Implications are presented for future research on adult social bonds as means of crime prevention and control, especially as they are related to gendered patterns of deviant association and lifestyle.

[Preventive effect of mecobalamin combined with glutathione on neurotoxicity induced by FOLFOX4 chemotherapy]

OBJECTIVE

To analyze the preventive effect of mecobalamin combined with glutathione on neurotoxicity induced by FOLFOX4 chemotherapy.

METHODS

Ninety-four patients receiving FOLFOX4 chemotherapy between January 2012 and December 2013 were randomized into experimental group and control group. Patients in the experimental group were given mecobalamin tablets and glutathione injection during chemotherapy while the patients in control group received glutathione injection only. The status of neurotoxicity was evaluated by the Levi neurotoxicity criteria 1992.

RESULTS

After six cycles of chemotherapy, the incidence of grade Ⅰ-Ⅱ neurotoxicity in the experimental and control groups were 34.7% (17/49) and 55.6%(25/45), respectively (P=0.042), the incidence of grade Ⅲ neurotoxicity in the experimental and control groups were 2.0%(1/49) and 13.3%(6/45), the difference is also statistically significant (P=0.037). After nine cycles of chemotherapy, significantly less grade Ⅰ-Ⅱ neurotoxicity was observed in the experimental group (44.6%) than that in the control group(70.3%, P=0.019). Incidence of grade Ⅲ neurotoxicity in the experimental group was significantly lower(4.26%) than that in the control group(18.9%, P=0.031).

CONCLUSION

Mecobalamin combined with glutathione can significantly reduce the incidence and severity of neurotoxicity induced by FOLFOX4 chemotherapy, therefore, worthy of clinical application.

Race, Self-Control, and Drug Problems among Jail Inmates

The main objectives of this study are to test racial differences in self-control and race-specific effects of self-control on drug-related problems. On the basis of prior research, it is hypothesized that both self-control and its effect on drug-related behavioral problems vary by race. Data collected from White, Black, and Hispanic inmates incarcerated in five local jails in the greater Philadelphia area were used to test these hypotheses. The results indicate significant racial differences in levels of self-control. However, the impact of self-control on drug problems did not differ significantly among the three racial groups. Overall, the findings support the argument of the general theory of crime that self-control maintains a constant and positive effect on deviant and criminal behavior across racial groups.

Comparative proteomic analysis of cauliflower under high temperature and flooding stresses

High-temperature and waterlogging are major abiotic stresses that affect the yield and quality of cauliflower. Cauliflower cultivars 'H41' and 'H69' are tolerant to high temperature and flooding, respectively; however, 'H71' is sensitive to both stresses. The objectives of this study were to identify the proteins that were differentially regulated and the physiological changes that occurred during different time periods in 'H41', 'H69', and 'H71' when responding to treatments of flooding, 40 °C, and both stresses combined. Changes in the leaf proteome were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and identified by Mascot peptide mass fingerprint (PMF) and database searching. Stress treatments caused significant reductions in electrolyte leakage, chlorophyll fluorescence Fv/Fm, chlorophyll content, and water potential as stress times were prolonged. By the comparative proteomic analysis, 85 protein peaks that were differentially expressed in response to combination treatments at 0, 6, and 24 h, 69 (33 in 'H41', 29 in 'H69', and 9 in 'H71') were identified, of which were cultivar specific. Differentially regulated proteins predominantly functioned in photosynthesis and to a lesser extent in energy metabolism, cellular homeostasis, transcription and translation, signal transduction, and protein biosynthesis. This is the first report that utilizes proteomics to discover changes in the protein expression profile of cauliflower in response to heat and flooding.

Significant variation of surface spin polarization through group IV atom (C, Si, Ge, Sn) adsorption on Fe3O4(100)

The adsorption of group IV atoms (C, Si, Ge, Sn) on the magnetite Fe3O4(100) surface is investigated by density functional theory calculations. All these atoms prefer to bond to the surface oxygen atom which has no tetrahedral Fe(A) neighbor. The spin-up surface states of clean Fe3O4(100) are completely removed and half-metallicity is recovered by C adsorption. The spin-up band gap of the C-adsorbed Fe3O4(100) surface is wider than that of the H-adsorbed one and closer to the value of bulk Fe3O4. For the adsorption of other group IV atoms, the adsorbate-substrate interaction decreases and the adsorbate-adsorbate interaction increases with the increase of atomic number Z. As a consequence, the spin polarization varies from -99.4% (C adsorption) to +44.2% (Sn adsorption) for the electronic states of the adsorbed atom integrated from -0.5 eV to the Fermi level. The ability to tune the surface spin polarization by the choice of adsorbate is of significance for magnetite-based spintronic devices.

Establishment of an acute rejection model by transplanting both renal grafts into two different rats using a modified method of ureterovesical anastomosis

OBJECTIVE

To establish an acute rejection model after kidney transplantation in the rat using a modified method of ureterovesical anastomosis.

METHODS

Thirty-nine Wistar rat donors, were transplanted into 70 male SD rats. Wistar rats (group 1; n = 18) underwent harvest of both kidneys, cold perfusion, and transplantation into 36 SD rats. Wistar rats (group 2; n = 18) underwent left kidney harvest, cold perfusion and transplantation into 18 SD rats. Groups 1 and 2 did not receive immunosuppression after transplantation. Six kidneys were harvested from 3 Wistar rats (group 3), were transplanted into 6 SD rats that were treated with CsA (5 mg/kg per day) postoperatively, and humanely killed at 21 days. There were 10 SD in sham operated rats (group 4). The renal allograft vein was end-to-end anastomosed to the recipient renal vein using an epidural catheter. The renal allograft was anastomosed end-to-side to the recipient abdominal aorta with an abdominal aortic flap. The renal allograft ureterovesical flap was directly inserted into the recipient bladder, and attached by 4-5 interrupted sutures. The recipient's right kidney vessels were ligated at 3 days postoperatively.

RESULTS

The success rates were 91.7% and 88.9% in groups 1 and 2, respectively. Except for the time for removal of the renal allografts, the operative durations and warm ischemia times differed insignificantly between both groups (P > .05). Blood creatinine levels increased significantly after kidney transplantation in groups 1 and 2 compared with the sham operated and CsA-treated cohorts (P < .01), but insignificantly between groups 1 and 2 (P > .05).

CONCLUSIONS

A dual renal allograft model was established in the rat using a modified ureterovesical anastomosis. The technique can be reproduced reliably, reducing costs and shorten using overall operative duration.

Efficacy of high-dose intra-dermal hepatitis B virus vaccine in previous vaccination non-responders with chronic liver disease

BACKGROUND

Hepatitis B virus (HBV) vaccination is essential in chronic liver disease (CLD), because it can help prevent acute-on-chronic disease, which has potentially fatal complications. Unfortunately, this group has a significant proportion of HBV vaccination non-responders. A variety of intra-muscular (IM) vaccination methods have been used in an attempt to remedy this poor-response, but with limited success.

AIMS

Herein is reported the safety and efficacy of high-dose intra-dermal (ID) HBV vaccination in CLD individuals who had failed previous IM standard and boost-dosing regimens.

METHODS

Forty-eight CLD individuals, known HBcAb negative, who had failed both a three-dose schedule of 40 μg IM vaccination, and boost dosing of either 40 or 80 μg IM, were identified, of which 42 completed the vaccination course. Each received a 40 μg ID total dose (20 μg per arm) during their clinic visits until a response was documented or a maximum of three doses had been administered. HBsAb titer ≥ 10 mIU/ml was regarded as an immunologic response; the intention was to achieve an optimum response of ≥ 100 mIU/ml.

RESULTS

Twenty-nine of forty-two (69%) individuals had an immunologic response, with 15 (51%) of the responders having the optimum response. No changes in serologic data occurred. No serious dermatologic reactions were observed. No differences between those who responded and those who did not were observed with regard to the presence of cirrhosis, diabetes mellitus, or chronic kidney disease.

CONCLUSIONS

High-dose ID HBV vaccination of previous CLD non-responders to the standard IM regimen with boost dosing is both safe and efficacious, and should be considered for all such groups.

Suitable calcineurin inhibitor concentrations for liver transplant recipients in the Chinese population

AIM

The aim was to deduce suitable calcineurin inhibitor concentrations for the Chinese liver transplantation population.

METHODS

We retrospectively studied 97 liver transplant recipients who displayed stable liver and renal function. No grafts were obtained from prisoners, procurements were performed with donor consent conforming to international ethics regulations. At 3, 6, and 12 months, we increased the concentrations and doses of calcineurin inhibitors as well as the values of alanine transaminase and serum creatinine.

RESULTS

Twenty-eight recipients received cyclosporine and 69 tacrolimus. The mean cyclosporine daily dosages were 203 ± 62 mg at 3, 188 ± 55 mg at 6, and 173 ± 52 mg at 12 months, the tacrolimus daily dosages were 3.08 ± 0.98, 2.82 ± 0.98, and 2.58 ± 0.93 mg, respectively. The corresponding mean cyclosporine peak concentrations (C(2)) were 806 ± 322 ng/mL, 681 ± 206 ng/mL, and 644 ± 190 ng/mL and the mean tacrolimus trought concentrations (C(0)) 6.61 ± 3.02 ng/mL, 5.85 ± 2.44 ng/mL, and 5.22 ± 2.33 ng/mL, respectively. In both groups, transaminases and serum creatinine were stable over time.

CONCLUSIONS

An individualized immunosuppressive regimen for the local population is necessary. We delayed calcineurin inhibitors with subsequent low-dose mycophenolate mofetil plus minimized calcineurin inhibitors, which seemed to be nephroprotective and safe for Chinese liver transplantation patients.

Large Low-Field Magnetoresistance in Nanocrystalline Magnetite Prepared by Sol−Gel Method

Nanocrystalline magnetite Fe3O4 samples with a grain size of about 40 nm have been synthesized by an optimized sol-gel method. The single phase of spinel magnetite was confirmed by both X-ray diffraction and transmission electron microscopy. It has been found that the magnetoresistance of the samples at low field (LFMR) is relatively large, and with the decrease of temperature its value at a field of 0.5 T changes dramatically from -2.5% at 300 K to -17.0% at 55 K. With the further decrease of temperature a sharp drop occurs for the magnitude of the magnetoresistance (MR), regarded as a spin (cluster) glass transition in the surface region of the grains that can be confirmed by the zero-field-cooled and field-cooled magnetization and ac susceptibility measurement. The mechanism of the magnetic and transport properties was discussed.

[STR polymorphisms in five Chinese ethnic groups(2)]

Population genetic studies were performed in Chinese Han, Hui, Mongolian, Tibetan and Uygur. Allele frequency distributions were analyzed for ten loci, i.e., D3S1358, VWA, CSF1PO, FGA, THO1, TPOX, D5S818, D13S317 and D7S820 by GeneScan. The results showed that there were 60 STR alleles and 149 genotypes in Han; 63 STR alleles and 144 genotypes in Hui; 69 STR alleles and 173 genotypes in Mongolian; 77 STR alleles and 168 genotypes in Tibetan; 70 STR alleles and 148 genotypes in Uygur. Significant differences were identified among ethnic groups (African-American, US-Caucasian and Chinese-Oriental), but similarity was found among the five Chinese populations, and immunogenomics and pharmacogenomics studied in this report. These findings indicated that the nine STR loci and amelogenin locus were very useful for individual identification in forensic science.

[Genescan for STR analysis and genetic distribution in a population sample from Han, China]

Genetic distributions for nine STR loci and Amelogenin locus were determined in a Chinese Han population based on DNA sequencing. The databanks in Chinese Population were generated by using Genescan, genotype and genetic distribution analysis. Allele frequency distribution was determined for 10 loci, such as D3S1358, VWA, FGA, Amelogenin, THO1, TPOX, CSF1PO, D5S818, D13S317 and D7S820. The results show significant differences between ethnic groups (African-American, US-Caucasian and Chinese Han) in the pattern of distribution as well as in the related frequency of the most common alleles of their STR loci. The probabilities of identity values for the population described in this section are 2.79 x 10(-10) (U.S-Caucasian), 1.23 x 10(-10) (African-American) and 0.5 x 10(-10) (Chinese Han). The results show the probability of Paternity Exclusion (PPE) values of 0.9998 (Chinese Han), 0.9996 (African-American) and 0.9994 (U.S-Caucasian). These results suggested that the nine STR loci and the Amelogenin locus are very useful for human identification, such as analyzing forensis casework, establishing DNA databanks, processing paternity test, evaluation linkage genetics, studying gene natural resources and monitoring bone marrow transplants.

Use of orbicularis oculi muscle flap for undercorrected blepharoptosis with previous frontalis suspension

The frontalis muscle and its fascia are connected with the orbicularis oculi muscle at the level of the eyebrow. Therefore, the superiorly based orbicularis oculi muscle flap, when advanced and attached to the tarsal plate, can dynamically elevate the upper lid and correct blepharoptosis with previous frontalis sling. Six patients with undercorrected blepharoptosis after frontalis sling suspension were included in this study. The superiorly based orbicularis oculi muscle flap was advanced to the tarsal plate in these patients and the redundant portion of the distal flap was resected. Postoperative results were satisfactory after 1-year follow-up.

Nutrition support for individuals with liver failure

The prevalence of liver diseases is increasing in the United States, particularly as a result of the recent hepatitis C epidemic. In the past, patients who developed fulminant hepatic failure or cirrhosis owing to a chronic liver disease were likely to expire. During the last 15-20 years, liver transplantation has given these patients a chance at survival. Progressive nutrition deficiencies and muscle wasting are universal problems in these patients. Left untreated, the progressive wasting of liver disease leads to infection and an increased risk of death owing to infection both before and after transplantation. Aggressive nutritional support is essential to optimize the care of these patients and to enable them to obtain and survive a liver transplant and gain access to a new life following a successful liver engraftment.

Drug Involvement, Lifestyles, and Criminal Activities among Probationers

The dynamic relationships among drug use, drug dealing, lifestyles, and crime were examined by interviewing probationers in three Northern Virginia counties. Results of the interviews showed that drug dealing had a positive effect on both property crime and violent crime while drug use had a significant effect only on property crime. It was also found that a significant number of drug offenders were involved in both the use and sale of drugs, which, in essence, had a powerful effect on other types of criminal activities. Additionally, results of the study revealed that the impact of drug use and drug dealing on crime was modified by individual lifestyles. Theoretical and policy implications of these findings are discussed.

Association between body mass index and adenocarcinoma of the esophagus and gastric cardia

Obesity is an increasing problem for industrialized nations. The incidence of adenocarcinoma of the esophagus and gastric cardia has also risen during the past two decades. A recently published population-based study attempted to relate this rise to increases in obesity or body mass index. Obesity may not only increase the risk for adenocarcinoma of the upper gastrointestinal tract, but it may also increase the risk of colon cancer and overall mortality. More research is needed to understand obesity's health impact and ways to control this epidemic.

Modulation of Helicobacter pylori induced interleukin-8 synthesis in gastric epithelial cells mediated by cag PAI encoded VirD4 homologue

BACKGROUND

Strains of Helicobacter pylori carrying the virulence associated cag pathogenicity island (PAI) induce gastric epithelial synthesis of the chemokine interleukin-8 (IL-8), a neutrophil chemoattractant, and thereby a strong inflammatory response during chronic infection of the human gastric mucosa. Previous mutational analyses have shown that many genes in the cag PAI are needed to elicit IL-8 synthesis in gastric epithelial cells, and also that some genes are not involved.

AIM

To test the possibility that certain genes in the cag PAI also downregulate (modulate) the inflammatory response elicited by cag+ H pylori infection.

METHODS

Cells of L5F11, a derivative of the Kato-3 gastric epithelial cell line that carries an engineered IL-8 promoter-luciferase reporter gene fusion, were cocultured with H pylori strain 26695 or with an isogenic mutant in which most of the cag PAI ORF 10 gene, an Agrobacterium virD4 homologue, was deleted. Luciferase activity was measured to assess IL-8 gene transcription and secreted IL-8 was measured by enzyme linked immunosorbent assay to assess synthesis and release of IL-8 protein from gastric epithelial cells.

RESULTS

Inactivation of ORF10 led to a 2.8-fold increase in IL-8 gene transcription and a 3.6-fold increase in IL-8 synthesis and secretion.

CONCLUSIONS

The results suggest that this VirD4 homologue participates in the control of inflammation that H pylori infection elicits by downregulating (modulating) the strong induction of IL-8 synthesis mediated by other cag encoded proteins.

Multiple genes in the left half of the cag pathogenicity island of Helicobacter pylori are required for tyrosine kinase-dependent transcription of interleukin-8 in gastric epithelial cells

Helicobacter pylori strains that contain the cag pathogenicity island (PAI) elicit increased synthesis of gastric C-X-C chemokines, promote neutrophilic infiltration into the gastric epithelium, and stimulate the synthesis of interleukin-8 (IL-8) in cultured gastric epithelial cells. To investigate the effects of cag PAI genes on the transcription of the IL-8 gene, the Kato-3 gastric epithelial cell line was stably transfected with plasmid DNA containing the IL-8 gene promoter fused to a luciferase reporter gene. The resulting reporter cell line, L5F11, was used to monitor the effects of infection in cell culture by H. pylori 26695 and isogenic derivatives with null mutations in genes in the cag PAI on transcription of the IL-8 gene. We found that null mutations in eight open reading frames, including homologs of the Agrobacterium virB9, virB10, and virB11 genes, in the left half of the cag PAI abrogated the induction of IL-8 gene transcription. Further studies with the L5F11 cell line showed that IL-8 gene transcription induced by H. pylori was blocked by the protein tyrosine kinase inhibitor herbimycin A but not by the protein kinase C inhibitor calphostin C or by the protein kinase G inhibitor KT5823. IL-8 gene transcription in L5F11 cells could also be induced by the cytokine tumor necrosis factor alpha (TNF-alpha) without exposure to H. pylori. This TNF-alpha-induced IL-8 transcription was inhibited by the protein kinase A inhibitor H7, which had no significant effect on H. pylori-induced IL-8 transcription. These studies show that multiple genes in the left half of the cag PAI are essential for the transcription of the IL-8 gene in gastric epithelial cells and that this depends on protein tyrosine kinase activation.

Breast-conserving radiation therapy: potential of inverse planning with intensity modulation

PURPOSE

To evaluate inverse planning with beam-intensity modulation in breast-conserving radiation therapy.

MATERIALS AND METHODS

A prototype inverse treatment-planning system was used in five patients with early-stage breast tumors. The prescription for the breast was 5,040 cGy in 180-cGy fractions, with the primary tumor site receiving 6,000 cGy in 214-cGy fractions. Isodose distributions from the prototype were compared section by section with those from conventional three-dimensional planning.

RESULTS

The inverse planning system showed dose variation of 84%-98% to 111%-113% in the primary tumor site. For whole-breast irradiation, 95% of the target volume received at least 4,000 cGy. High-dose areas were adjacent to the primary site. Lower-dose areas were in the most medial part of the breast. Compared with the conventional system, target doses were similar. The volume of lung and heart that received high doses was smaller; however, larger lung and heart volumes received doses of less than 1,200 cGy.

CONCLUSION

Intensity modulation may accomplish "concomitant boost" treatment. Acceptable dose gradients are achieved in the target volumes, with lower volumes of high-dose treatment in normal tissue. Plans that required comprehensive nodal radiation, in particular, were improved relative to conventional plans. Optimization of the planning system is needed to minimize the lung and heart volumes that receive low-dose radiation.

A method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy

PURPOSE

To develop a method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy.

METHODS AND MATERIALS

Dose-surface histograms of the rectum, which state the rectal surface area irradiated to any given dose, were calculated for a group of 27 patients treated with a four-field box technique to a total (tumor minimum) dose ranging from 68 to 70 Gy. Occurrences of rectal toxicities as defined by the Radiation Therapy Oncology Group (RTOG) were recorded and examined in terms of dose and rectal surface area irradiated. For a specified end point of rectal complication, the complication probability was analyzed as a function of dose irradiated to a fixed rectal area, and as a function of area receiving a fixed dose. Lyman's model of normal tissue complication probability (NTCP) was used to fit the data.

RESULTS

The observed occurrences of rectal complications appear to depend on the rectal surface area irradiated to a given dose level. The patient distribution of each toxicity grade exhibits a maximum as a function of percentage surface area irradiated, and the maximum moves to higher values of percentage surface area as the toxicity grade increases. The dependence of the NTCP for the specified end point on dose and percentage surface area irradiated was fitted to Lyman's NTCP model with a set of parameters. The curvature of the NTCP as a function of the surface area suggests that the rectum is a parallel structured organ.

CONCLUSIONS

The described method of analyzing rectal surface area irradiated yields interesting insight into understanding rectal complications in prostate conformal radiotherapy. Application of the method to a larger patient data set has the potential to facilitate the construction of a full dose-surface-complication relationship, which would be most useful in guiding clinical practice.

Nucleotide sequence of a 1446 base pair SalI fragment and structure of a novel early gene of Leucania separata nuclear polyhedrosis virus

A 1446 bp SalI fragment of LsNPV was sequenced by the silver staining method, and two large open reading frames (ORFs, ORF1 and ORF2) were found, both contain typical characteristics of the 5' regulatory elements of baculovirus early genes. ORF1 is 345 bp long with the capacity to encode a putative protein of 114 amino acid residues with MW about 13 kDa and was designated p13 gene, ORF2 comprises 248 bp from the 3' end of the fragment. In the untranslated region (UTR) of ORF1, a 33 bp mini cistron (ORF3), a core recognition sequence (CGTCG) for many bHLHzip transcription factors and a late promoter sequence TTAAG are present. In the UTR of ORF2, two host transcription factor binding elements (CACGTG and GATA motif) and two CGT motifs were found. Some regular leucine zipper-like structures, designated leucine trans-conformation structure and LVT repeat, were found near the N-terminus and the middle of p13 protein. The leucine trans-conformation structure that is near the N-terminus consists of 4 leucines and 7 other amino acids between every two leucines, and every leucine is located at a conformation shift point of the predicted secondary structure of the p13 protein. In LVT repeat, L-6aa-V-6aa-T-6aa is repeated once. The functions of those structures remain unclear, and the two ORFs, not found in the genome of Autographa californica nuclear polyhedrosis virus, are possibly two new genes.

[Cytogenetic study on a human colorectal carcinoma cell line (HR-8348)]

Cytogenetics of a human colorectal carcinoma cell line (HR-8348) established in China were described. The early (29th passage) and late passages (93th passage) of this cell line were used for chromosome analysis. HR-8348 was a cell line essentially with near triploid karyotype. The distribution of chromosome number was rather dispersed in the early passage, whereas it was concentrated to 65-70 range in the late passage. G-banding stain showed that the numerical distribution of different chromosomes was also dispersed in the early passage associated with abundant abnormal chromosomes. In the late passage, it turned to be more stable and the number of abnormal chromosomes reduced. In 60 metaphases analysed, 10 marker chromosomes were found. The frequency of M1, M3 and M2 was 100% in both early and late passages. The morphologic characteristics and their possible origin and role in the pathogenesis of colorectal carcinoma were discussed.

[Studies on cell surface fibronectin of transformed Syrian hamster lung cells induced by butyric acid]

In this paper, Fn was analysed qualitatively and quantitatively in three Syrian hamster cell lines, ie, nontransformed baby hamster lung fibroblasts cell line (BHL), a transformed cell line (BHLB4) and a butyric acid-induced phenotypically reversed cell line (ButB4) respectively. Fn was visualized on cell surface by means of indirect immunofluorescence technique. Immunofluorescence of Fn on the surface of BHL was bright with a stripe-like distribution, while that on the surface of BHLB4 was very dim or dispersed. On ButB4 cell surface, the intensity and distribution of immunofluorescence was similar to that on BHLB4 cells. Fn was isolated by affinity chromatography from the cell surface of the three cell lines. Its molecular weight was 250 kDa on SDS-polyacrylamide electrophoresis. The quantity of Fn isolated from surface of ButB4 was a bit lower than that from BHL, but was much higher than that from BHLB4. The result offers us a useful criterion for transformation and reverse transformation.

[Establishment of a human colonic carcinoma xenograft in nude mice and its chief biological characteristics]

A human colonic cancer specimen cut into 1-2 mm3 pieces under aseptic condition was heterotransplanted hypodermically by trocar to the inguinal region of BALB/cATcL nude mice bred in our laboratory. 53 days later, a 10 X 9 X 11 mm3 tumor was obtained. The take rate was 100% (48/48). The take rate of liquid nitrogen frozen and recovered tissue pieces was also 100% (13/13). Grossly, the tumor was rich in blood supply and well encapsulated. Within the tumor, the tissue was cream-colored. G-banded chromosome analysis revealed a human chromosome pattern with the mode 70-90. Pathologic diagnosis was signet-ring cell cancer, which was identical to the surgical specimen. No change was found after maintaining 13 passages in nude mice. It was named the human colonic carcinoma xenograft XHCn/w. It provides an ideal tumor model for in vivo or in vitro experiments.

[Cytogenetic studies on 3 esophageal cancer cell lines]

The cytogenetic studies on three esophageal cancer cell lines established in China were done. Thirty metaphases showing suitable chromosome length and good G-banding pattern from each of the cell lines were chosen and subjected to karyological analysis. The typical karyotypes from these cell lines were listed, and the variation of chromosome number as well as the morphological characteristics, possible sources and the incidence of the marker chromosomes were analysed. Eca 109 is the cell line first established and used extensively in China. A strictly regular karyotype pattern was found in it: the modal number of chromosomes being 63-64; the number of each type of chromosome varying between 1-5; a distal deletion of short arm of chromosome No. 1 being discernible in all metaphases, with break sites located within 1p22-1p33. Also a distal deletion of long arm of chromosome No. 4 was usually visible. There were seven marker chromosomes with high incidence. Among them, M1 marker chromosome was a large subacrocentric chromosome which was observed in the early passages of this cell line. The chromosome number of Ec 17 cell line was usually subtetraploid. In addition to the numerical variation in some of the chromosomes, six marker chromosomes were usually observed. Among them, M1 involved reciprocal translocation between chromosome No. 1 and No. 4. M3 of Ec 17 was in correspondence with M5 of Eca 109. Both were Rob (13q;14q). The chromosome number of Ec 56 was usually subtetraploid, and in addition to the numerical variation in some of the chromosomes, seven marker chromosomes were usually observed.

Evidence for the role of fibronectin in amphibian gastrulation

In amphibian embryos, fibronectin (FN) assembles as a fibrillar network on the roof of the blastocoel cavity, preceding mesodermal cell migration. Local inversion of the ectoderm to produce a site where no FN is available prevents mesodermal cell migration. Microinjection of monovalent antibodies to FN arrests gastrulation. A complete inhibition of mesodermal cell migration is obtained after microinjection of a synthetic peptide containing the cell binding site sequence of FN. Prevention of interactions between receptors and FN appears to be the primary cause for blockage of gastrulation.

Malignant transformation of baby hamster lung fibroblasts induced in vitro by a new nitrosamine compound

A new nitrosamine compound, N-1-methylacetonyl-N-3-methylbutyl-nitrosamine (MAMB-NA), isolated from corn bread inoculated with moulds commonly occurring in Linxian County, a high incidence area for esophageal cancer in North China was tested for its potential carcinogenicity in vitro. Baby hamster lung fibroblasts (BHL) were treated with MAMBNA in tissue culture medium containing liver microsome preparation of Aroclor 1254 treated rat. Cell transformation was assessed by morphological changes, loss of density-dependent inhibition and unlimited growth in vitro, chromosome changes, colony formation on soft agar, growth at low serum concentration, Con A agglutinability and tumor formation after heterotransplantation into immunosuppressed newborn rats. Like the known carcinogens N-methyl-N'-nitro-N-nitroso-guanidine and diethylnitrosamine, MAMBNA was able to cause malignant transformation of cells cultured in vitro.