Untargeted metabolomics of the intestinal tract of DEV-infected ducks

INTRODUCTION

Duck enteritis virus (DEV) mainly causes infectious diseases characterized by intestinal haemorrhage, inflammation and parenchymal organ degeneration in ducks and other poultry. However, the mechanism by which it causes intestinal damage in ducks is not well understood. Metabolomics can provide an in-depth understanding of the full complexity of the disease.

METHODS

In this study, 24 clinically healthy green-shell ducks (weight 1.5 kg ± 20 g) were randomly divided into 2 groups (experimental group, 18; control group, 6). The experimental group was intramuscularly injected with 0.2 mL of DEV virus in solution (TCID50 3.16 × 108 PFU/mL), and the control group was injected with 0.2 mL of sterile normal saline. Duck duodenum and ileum tissue samples were collected at 66 h, 90 h and 114 h post-injection (12 h of fasting before killing), and metabolomics analysis of duck duodenum and ileum tissues at the three time points (66, 90, 114 h) was performed by liquid chromatography-mass spectrometry (LC-MS) to screen for and analyse the potential differentiated metabolites and related signalling pathways.

RESULTS

Screening was performed in the positive/negative mode (Pos: Positive ion mode; the ionization of substances at the ion source with positive ions such as H+, NH4+, Na+ and K+; Neg: Negative ion mode; the ionization of substances at the ion source with negative ions such as Cl-, OAc-), and compound abundance was compared to that in the control group. The total number of differentially abundant compounds in the duodenum at 66 h, 90 h and 114 h of DEV infection gradually increased, and metabolites such as cytidine, 2'-deoxyriboside and 4-guanidinobutyric acid were differentially abundant metabolites common to all three time periods. The metabolic pathways related to inflammatory response and immune response were tryptophan acid metabolism, cysteine-methionine metabolism, histidine metabolism and other amino acid metabolism and fat metabolism. Among them, the metabolic pathways with more differentially abundant metabolites were amino acid biosynthesis, cysteine and methionine metabolism, tryptophan metabolism, unsaturated fatty acid biosynthesis and purine metabolism, and the metabolic pathways with more enrichment factors were the IgA-related intestinal immune network pathway and lysosome pathway. Compared with the control group, there were 16 differentially abundant metabolites in the ileum tissue of DEV-infected ducks at 66 h of infection, 52 at 90 h of infection, and 40 at 14 h of infection with TD114. The metabolic pathways with more enriched differentially abundant metabolites were pyrimidine metabolism, tyrosine metabolism, phenylalanine metabolism and tryptophan biosynthesis. The metabolic pathways with the most enrichment factors were the mTOR signalling pathway, ferroptosis pathway, tryptophan metabolism pathway and caffeine metabolism pathway.

CONCLUSION

Comparative analysis showed that the number of differentially abundant metabolites in the duodenum and ileum differed to some extent after DEV infection, with significantly more differentially abundant metabolites in duodenal tissues and fewer in ileal tissues; after DEV infection, the highest number of differentially abundant metabolites was obtained at 114 h of DEV infection, followed by the second highest at 90 h of infection and the lowest at 66 h of infection. The common differentially abundant metabolites in duodenal and ileal tissues were prostaglandins, arachidonic acid, and arachidonic ethanolamine. The main metabolic pathways in the duodenum were the IgA-associated intestinal immune network pathway and the lysosomal pathway, and the metabolic pathways with more enriched factors in the ileum were the mTOR signalling pathway, the ferroptosis pathway, and the tryptophan metabolism pathway.

Optimization of ultrasound-assisted extraction based on response surface methodology using HPLC-DAD for the analysis of red clover (Trifolium pretense L.) isoflavones and its anti-inflammatory activities on LPS-induced 3D4/2 cell

Introduction

Trifolium pratense L. has anti-inflammatory, antioxidant, cardiovascular disease prevention, and estrogen-like effects. The existing method for the assay of effective components is commonly based on a spectrophotometer, which could not meet the requirement of quality control. Furthermore, although there have been many studies on the anti-inflammation effect of red clover, a few have been reported on the regulatory effect of red clover isoflavones (RCI) on lipopolysaccharide (LPS)-induced inflammatory response in porcine alveolar macrophages (3D4/2 cells), and its mechanism of action is still unclear.

Methods

The main components of RCI including daidzein, genistein, and biochanin A were accurately quantified by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) after optimizing the extraction process through response surface methodology. The anti-inflammatory potential of RCI was carried out by detecting the level of inflammatory cytokines and mRNA expression of related genes. Furthermore, its anti-inflammatory mechanism was explored by investigating two signaling pathways (NF-κB and MAPK).

Results

The optimal extraction conditions of RCI were as follows: the concentration of ethanol is 86% and the solid-liquid ratio is 1:29, with the herb particle size of 40 mesh sieve. Under the optimal conditions, the total extraction of target components of RCI was 2,641.469 μg/g. The RCI could significantly suppress the production and expression of many pro-inflammatory cytokines. The results of the Western blot revealed that RCI dramatically reduced the expression of p65, p-p65, IκB-α, p38, and p-p38. These results are associated with the suppression of the signal pathway of p38 MAPK, and on the contrary, activating the NF-κB pathway. Collectively, our data demonstrated that RCI reversed the transcription of inflammatory factors and inhibited the expression of p65, p-p65, IκB-α, and p38, indicating that RCI had excellent anti-inflammatory properties through disturbing the activation of p38 MAPK and NF-κB pathways.

Conclusion

The extraction conditions of RCI were optimized by HPLC-DAD combined with response surface methodology, which will contribute to the quality control of RCI. RCI had anti-inflammatory effects on the LPS-induced 3D4/2 cells. Its mechanism is to control the activation of NF-κB and p38 MAPK pathways, thereby reducing the expression of inflammatory-related genes and suppressing the release of cytokines.

Establishing a Risk Stratification Model to Identify Clinically High-Risk N0 Breast Cancer Who Could Benefit from Regional Nodal Irradiation: A Single Institute Analysis

PURPOSE/OBJECTIVE(S)

The adverse clinical features for pN0 BC patients significantly varies and there is no established clinical risk stratification system to identify those "high-risk" pN0 BC patients who might benefit from RNI. The purpose of this real-world study was to investigate the risk factors for developing recurrence among patients with pathological T1-3N0 breast cancer (BC) treated with breast-conserving surgery (BCS) followed by whole breast irradiation alone (WBI) and identify those clinically high-risk BCs who could benefit from regional nodal irradiation (RNI).

MATERIALS/METHODS

Female BC patients treated from 2009 to 2016 were retrospectively reviewed. The disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method, and survival differences were compared with the log-rank test. Univariate and multivariate analysis was performed using Cox logistic regression analysis. An external validation was conducted by using SEER database.

RESULTS

A total of 622 BC patients treated with BCS+WBI alone were included. With a median follow-up of 82 months, the 7-year OS and DFS for the entire cohort was 97% and 91%, respectively. Multivariable Cox analysis indicated that tumor size (p = 0.006), tumor location (p = 0.033), lymphovascular invasion (LVI) status (p = 0.0028) and Ki-67 index (p = 0.051) were independent risk factors for DFS, while only tumor size was the only independent risk factors for OS (p = 0.029). A scoring system was developed using these four factors and the 7-year DFS and OS were 97% and 96% for patients with 0-1 risk factors, 95% and 82% for patients with ≥2 risk factors (p<0.0001 for DFS, and p = 0.0063 for OS). Based on tumor size and tumor location, an external validation by demonstrated that the 7-year OS was 90% and 88% for patients with 0-1 risk factor, which was significantly better than those defined as high-risk BC patients (82%, p<0.0001).

CONCLUSION

By using our institute database, we establish a risk stratification system for identifying sub-group of pN0 BC patients, who are at high risk for developing recurrence. The results of our study support tailored RT decision-making according to individual risks, which needed to be confirmed in further studies.

Treatment Outcomes and Prognostic Factors of Chemotherapy Combined with Radiotherapy for Patients with Stage I-II Nasal-Type Natural Killer/T-Cell Lymphoma

PURPOSE/OBJECTIVE(S)

The purpose of this study was to assess the treatment outcome and the potential prognostic factors for patients with stage I-II nasal ENKTL treated with radiotherapy (RT) combined chemotherapy (CT).

MATERIALS/METHODS

From July, 2005 to January, 2019, 118 eligible patients were retrospective included in the study. Among the 118 patients, 84 were male and 34 were female. The median age was 45 years (range: 14-77 years). According to the Ann Arbor staging system, 66 patients had stage I disease (Primary tumor invasion (PTI) was present in 29 patients), and 52 patients had stage II disease. B symptoms were observed in 61 patients. The Eastern Cooperative Oncology Group (ECOG) performance score was 0 to 1 in 88 patients. Cervical lymph node involvement was observed in 51 patients. The primary lesions were located in the nasal cavity in 92 cases and in the Waldeyer ring in 26 cases. Five patients had received RT followed by CT (RT + CT), 20 patients had received CT followed by RT (CT + RT), 90 patients had received CT followed by RT, again followed by CT (CT+RT+CT), and 3 patients had received concurrent chemoradiotherapy (CRT) (1 patient received CRT + CT, other 2 patients received CT+CRT+CT). Patients were irradiated with a median dose of 50 Gy (range, 24-61.2). All patients received chemotherapy, 91 received non-anthracycline-based chemotherapy, whereas 27 patients received anthracycline-based chemotherapy. The median number of courses of chemotherapy was four (range: 1-10). Patients were scored as having low-risk disease (n = 50), intermediate-risk disease (n = 60) or high-risk disease (n = 8) according to the prognostic index of natural killer cell lymphoma (PINK).

RESULTS

Among the 118 patients, after initial therapy, the complete response (CR) rate was 82.2% (n = 97), and the partial response (PR) rate was 11.0% (n = 13). The stable disease (SD) rate was 2.5% (n = 3), and the progressive disease (PD) rate was 4.2% (n = 5). With a median follow-up of 43 months (range, 4-201) after irradiation, the 3-year PFS and OS were 76.9% and 82.9%, respectively. The 3-year OS rate was 75.0% for RT + CT, 70.0% for CT + RT, 87.1% for CT + RT+ CT, and 50.0% for CRT (P = 0.052). Three-year OS and PFS were 88.6% and 83.4%, respectively, for non-anthracycline-based chemotherapy regimen compared to 61.6% (P = 0.001) and 58.4% (P = 0.003), respectively, for the anthracycline-based chemotherapy regimen. Three-year OS and PFS were 84.0% and 79.0%, respectively, for patients receiving high-dose RT (≥50 Gy, n = 111) compared to 71.4% (P = 0.076) and 71.4% (P = 0.228), respectively, for low-dose RT (<50 Gy, n = 7). In multivariate analysis, adverse factors associated with OS in our study were chemotherapy regimen and response to RT and CT (P = 0.047, <0.001).

CONCLUSION

Radiotherapy combined with chemotherapy reported promising response rate and a favorable survival for patients with stage I-II nasal ENKTL. Anthracycline-based chemotherapy regimen and no remission after RT and CT were adverse factors of OS.

Toripalimab Combined with Chemoradiotherapy for Locally Advanced Cervical Squamous Cell Carcinoma Patients: Early Results of Safety and Feasibility

PURPOSE/OBJECTIVE(S)

To assess the safety and efficacy of toripalimab combined with chemoradiotherapy for locally advanced cervical squamous cell carcinoma.

MATERIALS/METHODS

Twenty-two locally advanced cervical cancer patients, regardless of programmed death ligand-1 (PD-L1) status, received toripalimab treatment combined with concurrent chemoradiotherapy (CCRT), includes cisplatin (40 mg/m2, once a week for 5 weeks), radiotherapy (45-50.4 Gy/25-28Fx, 5 fractions a week, followed by brachytherapy 24-30 Gy/3-5Fx) and toripalimab (240mg on day 1, 22 and 43). The primary endpoints were safety and 2-year progression-free survival (PFS).

RESULTS

The median age was 55 years old (42 to 72), with 2 patients in FIGO stage Ⅱ, 15 patients in stage ⅢC, and 5 patients in stage ⅣA. All patients completed CCRT successfully. Grade Ⅲ and higher adverse events (AEs) were observed in 11 patients (11/22, 50%), and no patient had a grade Ⅴ AE. The most frequent grade Ⅲ AE was leukopenia (8/22, 36.4%). The most common immunotherapy-related adverse event was hypothyroidism (2/22, 9.1%). The objective response rate (ORR) was 100%. At data cutoff (Sep 30, 2022), the median follow-up was 19.7 months (7.67 to 26.1 months). The LC and the PFS rate were 95.5% and 81.8%, and the OS rate was 90.9%. The patients with baseline absolute lymphocyte count (ALC) ≤1.255 × 10^9/L had significant higher rates of metastasis than those with ALC >1.255 × 10^9/L (42.9% vs 0%, p = 0.023).

CONCLUSION

Toripalimab combined with CCRT achieved good tolerance and demonstrated promising anti-tumor effects in patients with locally advanced cervical cancer. Longer follow-up results and further phase Ⅱ/Ⅲ studies are expected. Chinese Clinical Trial Registry number, ChiCTR2000032879.

Analysis of authorized coccidiostats in chicken feces and environmental water by ultra-performance liquid chromatography-tandem mass spectrometry based on dispersive solid-phase extraction and lyophilization

A simple, sensitive, and efficient method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the determination of 8 coccidiostats in chicken feces and environmental water (including sewage, pond water, and lake water) surrounding the farm. Target analytes in chicken feces were extracted with 2% acetic acid in acetonitrile solution, followed by a dispersive solid-phase extraction (DSPE) cleanup step using the mixture of PSA and C18 adsorbents. Environmental water samples were pretreated using a lyophilization approach. Analysis was carried out on a UPLC-MS/MS with the combination of methanol and 0.1% formic acid aqueous solution as the mobile phase under multiple reaction monitoring in positive and negative ionization modes. Results showed that 8 coccidiostats were linear with correlation coefficients higher than 0.99. Method validation was performed using fortified samples, reaching satisfactory recoveries of 75.9%-97.8% in chicken feces and 71.9%-108.2% in environmental water. Limits of detection for 8 analytes in chicken feces and environmental water were 0.03∼2 µg/kg and 0.005∼1 µg/L, respectively. Matrix effects were calculated and strong signal suppression (>50%) for some coccidiostats was observed. The developed method was successfully applied to analyze coccidiostats in chicken feces and environmental water collected from local chicken farms.

The pharmacokinetic and residue depletion study of eugenol in carp (Cyprinus carpio)

Introduction

The pharmacokinetic profile and residue depletion of eugenol in carp (Cyprinus carpio) tissues and plasma were performed by a convenient and reliable high-performance liquid chromatography (HPLC) method.

Methods

The eugenol in carp tissues and plasma was extracted with a mixed solution of acetonitrile and methanol. N-hexane was used to remove lipid impurities. The method was successfully applied to the pharmacokinetic and residue elimination of eugenol in carp after the carp was administered a medicated bath.

Results

The average recoveries of eugenol in tissues and plasma fortified with four concentration levels were 69.0-106.6% and 80.0-86.7%, respectively. The relative standard deviations were < 8.9%. The limit of detection (LOD) was 0.01 μg/g in tissue and 0.008 μg/ml in plasma, respectively. The pharmacokinetic parameter of C_max for eugenol in plasma at the concentrations of 20, 35, and 75 mg/L were 10.86, 17.21, and 37.32 mg/L, respectively. The t_1/2 values were 3.68, 4.22, and 9.31 h. After the investigation of the anesthetic effect, 35 mg/L of eugenol was the optimal concentration for anesthesia. The highest accumulation concentration of eugenol in carp is in the liver and the lowest is in the muscle. In addition, the eugenol in tissue was eliminated rapidly and at a lower level than the LOD at 48 h. According to the residue elimination, the withdrawal time of eugenol was suggested at 5.2 days.

Discussion

These results indicate that the developed method had good linearity and accuracy, and is sensitive enough for the monitoring of eugenol residue in carp. The half-life of eugenol decreased with the increase in drug concentration and the eugenol was eliminated rapidly in carp tissues. 35 mg/L eugenol was recommended as an anesthetic in carp due to its favorable anesthetic effect and no mortality. This study will contribute to the establishment of MRL regulation and setting a withdrawal period.

Response Surface Optimization of Dispersive Solid-Phase Extraction Combined with HPLC for the Rapid Analysis of Multiple Coccidiostats in Feed

Since antimicrobials were banned as feed additives, coccidiostats with favorable anticoccidial action and growth promotion have been widely used in the breeding industry. The monitoring of coccidiostats in feed is necessary, while the current methods based on mass-spectrometer analysis have limited applicability and matrix effects could interfere with the results. Accordingly, in the present paper, a rapid analytical strategy for the simultaneous determination of six synthetic coccidiostats in feed using high-performance liquid chromatography coupled with diode-array detection was developed. Coccidiostats in chicken feeds were extracted with the trichloroacetic acid-acetonitrile solution. The cleanup was performed by dispersive solid-phase extraction after the optimization of the response surface methodology. The method exhibited good linearity for target coccidiostats within the range of 0.05~20 µg/mL. Recoveries for six compounds in fortified feed samples were from 67.2% to 107.2% with relative standard deviations less than 9.6%. The limit of detection was 0.2~0.3 mg/kg. The successful application of the method in commercial feed verified that it is effective and sensitive for the rapid determination of multiple coccidiostats in chicken feeds.

Outcome of postmastectomy radiotherapy after primary systemic treatment in patients with clinical T1-2N1 breast cancer

PURPOSE

The role of postmastectomy radiotherapy following primary systemic treatment in patients with clinical T1-2N1 breast cancer remains a controversial issue. The purpose of this study was to evaluate the benefit of postmastectomy radiotherapy following primary systemic treatment.

PATIENTS AND METHODS

Between 2005 and 2012, in two independent institutions, female patients with T1-2N1 breast cancer receiving primary systemic treatment followed by mastectomy and lymph node dissection because bad response, then treated with or without chest wall and regional lymph node irradiation have been studied retrospectively. The patients received normofractionated radiotherapy using 3D conformal photons or electron techniques. Locoregional recurrence-free survival, distant metastasis-free survival and disease-free survival were calculated using Kaplan-Meier method. Univariate analysis of potential prognostic factors was performed using log-rank test.

RESULTS

Eighty-eight patients have been studied. Of them, 75 patients received postmastectomy radiotherapy. At surgery, 53 patients achieved ypN0. Median follow-up was 67 months. Postmastectomy radiotherapy significantly improved locoregional recurrence-free survival, with a 5-year rate of 96.9% versus 78.6% in the group that did not have postmastectomy radiotherapy. In the subgroup of 53 patients achieving ypN0, postmastectomy radiotherapy improved locoregional recurrence-free survival (a 5-year rate of 94.7% vs. 72.9%), distant metastasis-free survival (a 5-year rate of 92.8% vs. 75%) and disease-free survival (a 5-year rate of 92.9% vs. 62.5%). By univariate analysis, postmastectomy radiotherapy was the only significant prognostic factor affecting locoregional recurrence-free survival.

CONCLUSIONS

For patients with clinical T1-2N1 disease, postmastectomy radiotherapy could significantly improve locoregional recurrence-free survival after primary systemic treatment and be even more therapeutic in the subgroup of patients with good response for primary systemic treatment by improving locoregional recurrence-free, distant metastasis-free and disease-free survival. Larger prospective studies are needed to confirm our findings.

Job Design and Levels of Physical and Mental Strain among Prison Officers

In this paper the preliminary results of a four year longitudinal study concerned with job design and levels of strain among a population of Prison Officers are reported. The job design factors that were studied related to perceived demands, constraints and supports. It was hypothesised that (i) those officers who perceive themselves as having jobs high in demand and level of constraint would suffer more strain than those of equal demand but who had a greater decision latitude (i.e., fewer constraints). It was further hypothesized that (ii) those in highly demanding and constrained jobs would show fewer strain symptoms if the environment in which they worked was perceived as providing social support. Preliminary analysis of the data shows that the first hypothesis was not supported for a measure of general physical well-being. However, there was evidence that those working in high security prisons showed significantly lower levels of general physical health than those working in low security environments. For measures of psychological well-being both hypotheses (i) and (ii) were partially supported. Those who perceived themselves as having high levels of support were found to suffer less from anxiety and depression. These effects were most apparent in the higher security prisons. Additional analyses have shown that the demands supports and constraints model is probably too simplistic and that other variables (e.g. personality) and further refinements to the model would help to account for additional variance in the measures of strain.

Antiproliferation activity of Devil's club (Oplopanax horridus) and anticancer agents on human pancreatic cancer multicellular spheroids

Devil's club (DC, Oplopanax horridus) is an important medicinal herb of the Pacific Northwest which has significant antiproliferation activity against a variety of human tumor cell lines in vitro. This study compared the antiproliferation activity of DC extract alone, and in combination with chemotherapeutic agents gemcitabine (GEM), cisplatin (CDDP), and paclitaxel (PTX) on human pancreatic cancer PANC-1 3D spheroids and 2D monolayer cells. 3D tumor spheroids were prepared with a rotary cell culture system. PANC-1 3D spheroids were significantly more resistant to killing by DC extract, GEM and PTX compared to 2D cells, with IC50 levels closer to that observed in vivo. DC extract significantly enhanced the antiproliferation activity of CDDP and GEM at some concentrations. The bioactive compound identified as a polyacetylene showed strong antiproliferation activity against PANC-1 2D cells and 3D spheroids with IC50 at 0.73±0.04 and 3.15±0.16μM, respectively. 3D spheroids and 2D cells differentially expressed a number of apoptosis related genes. Cell cycle analysis showed that the proportion of cells in S phase was increased and in G2/M phase reduced in 3D spheroids compared to 2D cells. DC extract can potentially be used to enhance the activity of chemotherapeutic agents against pancreatic cancer cells. Use of 3D spheroid model for screening of natural products can potentially increase the efficiency in discovering in vivo bioactive compounds.

[Tryptase of mast cells in immune organs of developing chicken embryos]

OBJECTIVE

To observe the form, distribution and emerging time of the mast cells (MCs) and tryptase positive cells (TPCs) in the immune organs of different days old chicken embryos.

METHODS

The thymus, bursa of Fabricius and spleen of chicken embryos at different development time were taken and fixed in Carnoy's solution. The alcian blue/safranine O (AB/SO) and streptavidin-biotin complex (SABC) immunohistochemistry were used to observe the MCs and TPCs.

RESULTS

MCs were first present in the thymus, bursa and spleen of day 13-14 embryos. The number of MCs increased along with the development days. On day 16, TPCs were first found in the immune organs. The form and distribution of TPCs were similar to MCs, but the emerging time of TPCs was later than that of MCs.

CONCLUSION

Tryptase appears in the MCs in the immune organs of day 16 or later chicken embryos, and it is mainly located in the MCs of the connective tissues.

Dietary arginine supplementation affects microvascular development in the small intestine of early-weaned pigs

This study was conducted to evaluate the effects of dietary arginine levels on microvascular development of the small intestine in early-weaned pigs. Twenty-four crossbred pigs (5.0 +/- 0.3 kg body weight) were individually housed and randomly allotted to 1 of 3 diets supplemented with 0, 0.7, and 1.2% L-arginine (8 pigs per group). Pigs consumed the diets ad libitum for 10 d. We collected blood samples on d 3, 6, and 10. On d 10, 6 pigs from each group were randomly selected and killed for tissue sample collection. Compared with control pigs, dietary supplementation with 0.7% L-arginine increased (P < 0.05) jejunal concentrations of nitrite and nitrate (stable oxidation products of nitric oxide), intestinal villus height, as well as plasma proline and arginine concentrations on d 6 and 10. Dietary supplementation with 0.7% L-arginine also increased (P < 0.05) immunoreactive expression of CD34 in duodenal submucosa, ileal mucosa and submucosa, and expression of vascular endothelial growth factor (VEGF) in duodenal submucosa, jejunal mucosa and submucosa, and ileal mucosa compared with the control and 1.2% L-arginine supplementation. Dietary supplementation with 1.2% L-arginine increased (P < 0.05) the concentration of jejunal endothelin-1 compared with the control pigs. Immunoexpression of VEGF in duodenal mucosa and plasma lysine concentrations on d 6 and 10 were lower (P < 0.05) in pigs supplemented with 1.2% L-arginine than in unsupplemented pigs. Collectively, these findings indicate that the effects of L-arginine on microvascular development are beneficial at lower levels but have adverse effects at higher intakes. Dietary supplementation with 0.7% L-arginine may be a useful method to improve microvascular development in the small intestine of early-weaned pigs.

Recombinant soybean protein beta-conglycinin alpha'-subunit expression and induced hypersensitivity reaction in rats

BACKGROUND

The major storage protein in soybean seed is beta-conglycinin and this protein has been identified as being responsible for food-allergic reactions in several species. However, the mechanism through which beta-conglycinin induces an allergic reaction has not yet been elucidated. In addition, assessing the antigenic activity of beta-conglycinin by studying the activity of a subunit has rarely been conducted. Therefore, the objective of the present study was to characterize the antigenic specificity of the beta-conglycinin alpha'-subunit.

METHODS

We established an Escherichia coli expression system to obtain beta-conglycinin alpha'-subunit. The fusion proteins were then used in a rat model to induce a hypersensitive reaction. Immunoblotting, IgE and IgG1 level, histamine release, and passive cutaneous anaphylaxis reactions and intestinal histology were tested to assess the allergenic activity of the beta-conglycinin alpha'-subunit.

RESULTS

Pure beta-conglycinin alpha'-subunit was obtained by expression in E. coli. The recombinant proteins were shown to have the same biological activity as the natural beta-conglycinin alpha'-subunit using immunoblotting analysis. Both the IgE and IgG1 level in serum and the histamine concentration in the intestine were increased while passive cutaneous anaphylactic reactions were induced in Brown Norway rats by intragastric gavage with the alpha'-subunit. Histamine release of mast cells was also elevated in vitro.

CONCLUSIONS

Our results indicate that the beta-conglycinin alpha'-subunit possesses an intrinsic immune-stimulating capacity and that it can induce an allergic reaction. Moreover, this study showed that beta-conglycinin alpha'-subunit-induced anaphylaxis is IgE mediated, and mast cell degranulation and histamine release are associated with anaphylactic symptoms.

Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.

Characterization of the antigenic specificity of soybean protein β-conglycinin and its effects on growth and immune function in rats

The objective of the present study was to characterize the antigenic specificity of purified soybean beta-conglycinin and to investigate its effects on the growth and immune responses of rats. Thirty-two Brown Norway rats, 3 weeks of age, were randomly allotted to one of four treatments and individually fed casein-cornstarch based diets. Rats were sensitised by means of intragastric gavage with purified beta-conglycinin (0, 5, 10 or 20 mg protein/ml in phosphate buffered saline at pH 7.4) on day 0, 7, 14, and 21 (1 ml/animal). On day 28, rats received a double dose of beta-conglycinin. Blood was obtained at weekly intervals after initiation of challenge. Growth declined linearly with increasing the concentration of soybean beta-conglycinin (p < 0.05). Both the total IgE and beta-conglycinin-specific IgE levels in serum increased while passive cutaneous anaphylactic reactions were induced in the rats. Lymphocyte proliferation response to concanavalin A in plasma and spleen was increased linearly with increased levels of soybean (p < 0.01) beta-conglycinin. The percentage of CD4+ lymphocyte subset linearly increased (p < 0.001). As a result, the concentrations of cytokines in plasma and spleen, including interleukin-4 (p < 0.01), interleukin-5 (p < 0.01), and tumour necrosis factor-alpha (p < 0.01) increased linearly with increasing level of purified beta-conglycinin. Our results indicate that purified beta-conglycinin possesses intrinsic immune-stimulating capacity and can induce an allergic reaction. Therefore, dietary soybean beta-conglycinin has negative effects on growth and both cell-mediated and humoral immune function in rats.

Dietary supplementation with zinc oxide decreases expression of the stem cell factor in the small intestine of weanling pigs

Dietary supplementation with a high level of zinc oxide (ZnO) has been shown to reduce the incidence of diarrhea in weanling pigs, but the underlying mechanisms remain largely unknown. Intestinal-mucosal mast cells, whose maturation and proliferation is under the control of the stem cell factor (SCF), play an important role in the etiology of diarrhea by releasing histamine. The present study was conducted to test the novel hypothesis that supplementing ZnO to the diet for weanling piglets may inhibit SCF expression in the small intestine, thereby reducing the number of mast cells, histamine release, and diarrhea. In Experiment 1, 32 piglets (28 days of age) were weaned and fed diets containing 100 or 3000 mg zinc/kg (as ZnO) for 10 days (16 piglets per group). In Experiment 2, two groups of 28-day-old piglets (8 piglets per group) were fed the 100- or 3000-mg zinc/kg diet as in Experiment 1, except that they were pair-fed the same amounts of feed. Supplementation with a high level of ZnO reduced the incidence of diarrhea in weanling piglets. Dietary Zn supplementation reduced expression of the SCF gene at both mRNA and protein levels, the number of mast cells in the mucosa and submucosa of the small intestine and histamine release from mucosal mast cells. Collectively, our results indicate that dietary supplementation with ZnO inhibits SCF expression in the small intestine, leading to reductions in the number of mast cells and histamine release. These findings may have important implications for the prevention of weaning-associated diarrhea in piglets.

Calcium antagonist verapamil prevented pulmonary arterial hypertension in broilers with ascites by arresting pulmonary vascular remodeling

Calcium signaling has been reported to be involved in the pathogenesis of hypertension. Verapamil, one of the calcium antagonists, is used to characterize the role of calcium signaling in the development of pulmonary arterial hypertension syndrome in broilers. The suppression effect of verapamil on pulmonary arterial hypertension and pulmonary vascular remodeling was examined in broilers, from the age of 16 days to 43 days. Our results showed that oral administration of lower dose of verapamil (5 mg/kg body weight every 12 h) prevented the mean pulmonary arterial pressure, the ascites heart index and the erythrocyte packed cell volume of birds at low temperature from increasing, the heart rate from decreasing, and pulmonary arteriole median from thickening, and no pulmonary arteriole remodeling in broilers treated with the two doses of verapamil at low temperature was observed. Our results indicated that calcium signaling was involved in the development of broilers' pulmonary arterial hypertension, which leads to the development of ascites, and we suggest that verapamil may be used as a preventive agent to reduce the occurrence and development of pulmonary arterial hypertension in broilers.

HCHs and DDTs in sediment-dwelling animals from the Yangtze Estuary, China

HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were determined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g(-1) and averaged 3.5 ng g(-1) in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g(-1), with a mean of 34.5 ng g(-1). In crabs t-HCH concentrations varied from 2.0 to 25.7 ng g(-1) and averaged 13.8 ng g(-1), whereas the concentrations of t-DDT were in the range of 1.5-24.8 ng g(-1) with a mean value of 5.9 ng g(-1). The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackish water area, such as FX site, and little difference between species. Results also indicate there was no significant relationship between t-HCH (t-DDT) concentrations and lipid contents both in mollusks and crabs because of non-equilibrium state under a specific estuarine dynamics; smaller individuals accumulated more HCHs and DDTs than larger individuals of mollusks at LHK site, showing different uptake rate for these pesticides; moreover, HCHs and DDTs levels were lower in female crab bodies than male crab bodies suggesting that the release of spawning. BSAFs (Biota- Sediment Accumulation Factors) from sediment-dwelling animals for HCHs and DDTs show a significant "one high with two low" and "one low with two high" effect in the Yangtze Estuary.

HCHs and DDTs in salt marsh plants (Scirpus) from the Yangtze estuary and nearby coastal areas, China

HCHs and DDTs in salt marsh plants taken from intertidal flats in the Yangtze estuary and coastal area in April and July 2002 were determined by GC-ECD. A significant seasonal effect was observed for HCHs and DDTs in sources and concentration levels in different sample types including above-ground tissues and roots as well as the whole plants and rhizospheric sediments. The results indicated that the concentration of t-HCH was higher in the above-ground tissues than in their roots in April; however, the partitioning of DDTs between contaminated sediments and the roots showed the higher concentrations of t-DDT in their roots. HCHs and DDTs concentration levels were higher in above-ground tissues than in roots in July. BCFs of HCHs and DDTs exhibited lower values with higher levels of contaminants in sediments, and higher values with lower levels in sediments.

Regulation of TNF-Related Apoptosis-Inducing Ligand-Mediated Death-Signal Pathway in Human β Cells by Fas-Associated Death Domain and Nuclear Factor κB

Transfectants of human CM and NES2Y beta cell lines and primary islets transfected by FADD-DN (dominant-negative form of Fas-associated death domain), a mutant of FADD and/or a superrepressor of nuclear factor kappaB (NF-kappaB) (AdIkappaB(SA)2), were examined for their susceptibility to the TRAIL (TNF-related apoptosis-inducing ligand)-induced death signal pathway, compared with controls, wild-type cells, and vector transfectants in caspase fluorescence, Western blot, electrophoretic mobility shift, apoptosis, and cytotoxicity assays. FADD-DN inhibited caspase-8 activation induced by TRAIL in the transfectants of CM and NES2Y cells. TRAIL-induced apoptosis and cytotoxicity to the FADD-DN transfectants were decreased in comparison to those responses in controls (CM, p < 0.01 and p < 0.01; NES2Y, p < 0.05, and p < 0.02, respectively). When CM, NES2Y, and primary islet cells were transfected by AdIkappaB(SA)2, TRAIL-induced IkappaB degradation and nuclear translocation of NF-kappaB p50/p65 were blocked. TRAIL-induced apoptosis and cytotoxicity to AdIkappaB(SA)2 transfectants of these cells were also reduced (CM, p < 0.02 and p < 0.02; NES2Y, p < 0.01 and p < 0.01, respectively, and islet p < 0.01 for cytotoxicity). Finally, cytotoxicity induced by TRAIL in CM and NES2Y cells transfected with both FADD-DN and AdIkappaB(SA)2 was reduced, compared with that observed in these cells transfected with either FADD-DN alone or AdIkappaB(SA)2 alone, suggesting that FADD and NF-kappaB have synergistic proapoptotic regulatory effects on the susceptibility of beta cell lines and islet cells to TRAIL-induced destruction.

Endothelin-1 Receptor Antagonist BQ123 Prevents Pulmonary Artery Hypertension Induced by Low Ambient Temperature in Broilers

Evidence has indicated that endothelin-1 is related to the pathogenesis of hypertension. To characterize the role of endothelin-1 (ET-1) in the development of pulmonary hypertension syndrome in broilers, the blockade effect of ETA receptor (ET(A)) antagonist, BQ123, on blood pressure in experimental models of pulmonary hypertension was examined. Birds were locally anesthetized and instrumented with venous catheters for pulmonary arterial pressure (PAP) and right ventricular pressure (RVP), followed by packed cell volume (PCV) and Ascites heart index (AHI) measured, after exposed to low ambient temperature for 7 or 14 d. In treated groups, BQ123 (0.4 or 2.0 microg each time, 2 times a day), administered in abdominal cavities for 7 or 14 d during birds kept in low ambient temperature, prevented both PAP and RVP increasing, especially the high dose BQ123 lowered PAP and RVP to normotensive levels as that in control under normal temperature, whereas significant increases (p<0.05) were found in the two parameters of broilers in both untreated and saline treated group under low ambient temperature compared with those of birds in control. Furthermore, there was also a reduction in low ambient temperature-induced right ventricular hypertrophy in the groups administered BQ123. The preventive effect of BQ123 suggests that ET-1 is associated with the development of broilers' pulmonary hypertension, which leads to the development of ascites, and BQ123 can prevent the occurrence of pulmonary hypertension.

TNF-related apoptosis-inducing ligand death pathway-mediated human beta-cell destruction

AIMS/HYPOTHESIS

The aim of this study is to investigate whether apoptosis in human beta cells can be related to the induction of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway.

METHODS

We examined the expression of TRAIL and TRAIL receptors in two human pancreatic beta-cell lines and in human primary islet cells using RT-PCR assays and flow cytometric analyses and tested TRAIL-mediated beta-cell destruction in (51)Cr release cytotoxicity assays, Annexin-V and APO-DIREC assays.

RESULTS

Most of the human beta cells express TRAIL receptors-R1, -R2, -R3, -R4 and/or TRAIL. TRAIL induced much stronger cytotoxicity and apoptosis to beta-cell lines CM and HP62 than did FasL, TNF-alpha, LTalpha1beta2, LTalpha2beta1, LIGHT, and IFN-gamma. The cytotoxicity and apoptosis induced by TRAIL to beta-cell lines CM were inhibited competitively by soluble TRAIL receptors, R1, R2, R3 or R4. Treatment of these beta cells with antibodies against TRAIL receptors was able to block the cytotoxicity of TRAIL to these cells. Beta-cell antigen-specific CTL (CD4(+) and CD8(+)) clones express TRAIL, suggesting that these cells are potential sources of TRAIL-inducing beta-cell destruction. Normal primary islet cells from most donors are resistant to the cytotoxicity mediated by TRAIL. However, treatment with an inhibitor of protein synthesis (cycloheximide) or with an enzyme (PI-PLC) that can remove TRAIL-R3 from the islet-cell membrane was able to increase the susceptibility of TRAIL-resistant primary islet cells to the TRAIL death pathway.

CONCLUSION/INTERPRETATION

The TRAIL death pathway is present and can function in human islet beta cells, but unidentified inhibitors of the TRAIL death pathway are present in normal islet cells.

Increased cytosol Ca(2+) and type 1 programmed cell death in Bcl-2-positive U937 but not in Bcl-2-negative PC-3 and Panc-1 cells induced by the 5-lipoxygenase inhibitor MK 886

MK 886, an arachidonic acid-related analog which inhibits the enzyme, 5-lipoxygenase by an indirect mechanism involving the 5-lipoxygenase activating protein, rapidly increased U937 cytosol Ca(2+), much of which localized around the cell nuclei. Five-lipoxygenase activity was not directly involved since the direct redox-dependent 5-LPOx inhibitor, SC-41661A did not increase Ca(2+). U937 cells subsequently undergo classic type 1 programmed cell death. At least initially the ionized calcium originates from internal stores. Coincident with the rise in U937 ionized calcium, MK 886 rapidly increased reactive oxygen species and reduced mitochondrial membrane potential, as judged by several fluorescent probes. The Ca(2+) response of myeloid leukemia-derived HL-60 cells to MK 886 was similar and both cell lines express Bcl-2 protein. Bcl-2-negative Panc-1 and PC-3 cells did not respond to MK 886 with a Ca(2+) signal but did develop oxidative stress and a decline in mitochondrial membrane potential; these events are thought to contribute to the inhibition of cell proliferation and induction of a type 2 PCD. In addition to its marked inhibition of Bcl-2 mRNA synthesis, an interesting hypothesis is that MK 886, serving as a low molecular weight ligand, either by direct or indirect inhibition of U937 Bcl-2 protein function, possibly related to an ion channel activity, alters the distribution of intracellular, possibly nuclear Ca(2+), thereby promoting the development of type 1 programmed cell death.

A response of Panc-1 cells to cis-platinum, assessed with a cDNA array

BACKGROUND

The problem posed by the lack of response of cells in most solid cancers to current chemotherapy generally remains intractable.

MATERIALS AND METHODS

The use of cDNA arrays represents one global approach to identifying reasons for this failure. A messenger RNA response of pancreatic cancer (Panc-1) cells after culture for 24 hours with 12 microM cis-platinum was analyzed with a commercial cDNA array.

RESULTS

Major drug-induced events included inhibition of messenger RNAs associated with cell proliferation and up-regulation of generally countervailing DNA repair, cellular stress, heat shock protein, glutathione stress-related and multiple drug resistance enzyme messenger RNAs, accompanied by a limited programmed cell death response.

CONCLUSION

Induction of widespread normal stress-induced countervailing mRNAs by comparatively non-selective agents such as cis-platinum strongly biases against a successful therapeutic outcome. This paradoxical result of a therapeutic intent provides a further compelling argument for the use of specifically-targeted therapy such as growth factor receptor, tyrosine kinase and other discretely focused agents, probably employed in combinations based on expression of their targets in an individual patient's cancer, as identified by cDNA or proteonomic arrays.

Antibiotic treatment for threatened abortion during the early first trimester in women with previous spontaneous abortion

BACKGROUND

We retrospectively examined the usefulness of antibiotic therapy for management of first-trimester threatened abortion in women with previous spontaneous abortion.

METHODS

From 1993 through 1999, women with first-trimester threatened abortion received antibiotic therapy. Only those with gestational age less than 9 weeks and previous spontaneous abortion were included in this analysis. Women with mild abdominal cramping received amoxicillin plus erythromycin for 1 week; those with severe abdominal pain received amoxicillin plus clindamycin for 1 week. Recurrence was documented on the basis of either lower abdominal pain or vaginal bleeding.

RESULTS

Of the 23 women included, 15 (65%) had abnormal vaginal flora (a score above 4, Nugent's criteria). Seven of 16 women who received amoxicillin plus clindamycin and three of seven who received amoxicillin plus erythromycin had complete resolution of lower abdominal pain and vaginal bleeding without recurrence (p=1). The recurrence rate was higher, though not significantly, in women with abnormal bacterial vaginal flora (8/15 vs. 2/8, p=0.379). Twenty-two (96%) of the 23 pregnancies were carried to term, with no identifiable neonatal anomalies.

CONCLUSIONS

These results suggest the usefulness of early antibiotic therapy in preventing pregnancy loss in women with threatened abortion early in the first trimester, and warrant further clinical trials.

The mode of cell death in H-358 lung cancer cells cultured with inhibitors of 5-lipoxygenase or the free radical spin trap, NTBN

The 5-lipoxygenase inhibitors SC41661A and MK886 with different mechanisms of action and the free radical spin trap, NTBN inhibit proliferation of the human bronchiolar lung cancer cell line NCI H-358 (5807 CRL). With continued culture, the agents induced a form of programmed cell death in which DNA laddering was not detected and ultrastructural changes were not characteristic of classic 'type 1' cellular suicide. The changes were more consistent with a type 2 cytosolic, autophagic form of PCD. MK886 induced strikingly abnormal mitochondrial morphology. Since the lipoxygenase inhibitors and NTBN induce classic type 1 PCD in U937 monoblastoid cells, these agents can activate either pathway, depending upon cell type. It is not certain whether activation of type 1 or 2 pathways depends entirely upon cell lineage and/or initiating agent, if all cells retain both pathways, and if type 1 PCD a more effective mediator of the process. These are all relevant questions for assessing the impact of PCD on malignant cell survival and considering ways in which it might be enhanced.

Cross-reactive rubella virus and glutamic acid decarboxylase (65 and 67) protein determinants recognised by T cells of patients with type I diabetes mellitus

AIMS/HYPOTHESIS

To examine the cross-reaction between viral and beta-cell protein determinants and to further understand the potential role of this mechanism in Type I (insuline-dependent) diabetes mellitus.

METHODS

Immune responses to a panel of 28 viral and beta-cell protein peptides representing selected sequences of rubella virus (RV), Coxsackie virus, human 38 KDa31G and glutamic acid decarboxylase (GAD 65 and 67) proteins in proliferation or cytotoxicity assays have been studied using uncloned and cloned T-cell cohorts from a group of 60 Type I diabetic patients.

RESULTS

Peptide GAD65(252-266) induced the responses of patients with recent onset diabetes in proliferation assays at the highest frequency (77%), whereas GAD67(212-226) stimulated the cellular responses at the highest rate (61%) in patients with late-onset diabetes. RVE1(157-176) was recognised by all groups of patients at the highest frequency and the largest amplitude among the viral peptides tested. T-cell clones specific to GAD65(252-266), GAD65(274-286) or GAD67(212-226) were tested in cytotoxicity assays for their responses to rubella virus peptides. Each of these T-cell clones cross-reacted with two to four rubella virus peptides, including RVE1(157-176) and RVE2(87-107). Analysis of the sequences of cross-reactive viral and glutamic acid decarboxylase antigens showed that these epitopes shared similar peptide binding motifs to HLA DR3/DR4. There is a statistically significant correlation between the response amplitude of patient's peripheral blood mononuclear cells to RVE1(157-176), RVE2(87-107) and GAD65(274-286) in patients with recent onset diabetes, and to RVE1(157-176) and GAD67(212-226) in patients with late onset diabetes.

CONCLUSION/INTERPRETATION

Cross-reactive glutamic acid decarboxylase and rubella virus determinants identified by T-cell clones were also recognised at high frequencies by general T-cell populations of Type I diabetic patients.

Altered oncogene, tumor suppressor and cell-cycle gene expression in PANC-1 cells cultured with the pleiotrophic 5-lipoxygenase inhibitor, MK886, assessed with a gene chip

We describe a genomic response of mRNAs associated with a subset of oncogenes, tumor suppressor and cell cycle-related genes in proliferating human Panc-1 pancreatic cancer cells after 24 hours of culture with MK886, a pleotrophic 5-lipoxygenase inhibitor. Ninety-eight of these cDNAs are represented in one of the sub-arrays included in the Clontech Human cDNA Expression Array. In this initial analysis, control cells exhibited apparent widespread low levels of disparate mRNA synthesis. In cells cultured with 40 microM MK886 for 24 hr, while most expressed genes, including a number of specific proliferation-enhancing genes such as c-myc were inhibited, 19 other ones including some countervailing genes including tyrosine SRC protein kinase, cyclins B1 and D1, CDC25B phosphatase and 40s ribosomal S19, amounting to 19 percent of the cDNAs resident on the chip were up-regulated at > 1.10 experimental/control values. Therapy-induced activation of compensatory proliferative genomic responses provides an additional explanation why malignant cells can fail therapy. Among their many future uses, gene chips clearly will be an extremely powerful tool for identifying relationships between the hierarchical linear and non-linear control and implementation-related cellular events and for identifying potential molecular targets tor cancer therapy.

CD4+ and CD8+ T-cell clones from congenital rubella syndrome patients with IDDM recognize overlapping GAD65 protein epitopes. Implications for HLA class I and II allelic linkage to disease susceptibility

To fully characterize human glutamic acid decarboxylase (GAD)65 protein T-cell epitopes associated with insulin-dependent diabetes mellitus (IDDM), CTL clones specific to GAD65 protein antigens were isolated from two congenital rubella syndrome (CRS)-associated IDDM patients. Overlapping nonamer T-cell epitopes recognized by both CD4+ or CD8+ CTL clones within peptides GAD65(252-266) and GAD65(274-286) were identified as sequences bounded by GAD65(255-266) with 6/9 overlapping residues, and GAD65(276-285) with 8/9 overlapping residues, respectively, using two panels of overlapping peptide analogs in cytotoxicity assays. HLA restrictive elements of the T-cell clones were also identified using a panel of B cell lines with different HLA phenotypes as targets in cytotoxicity assays. The antigenic GAD65 peptides elicited cytotoxic responses of peptide-specific CD4+ T-cell clones in the context of HLA DRB1*0404. The CD8+ T-cell clone specific to GAD65(255-263) was found to be restricted by HLA A3 and A11. Similarly, the CD8+ T-cell clone specific to GAD65(277-285) killed peptide-sensitized target cells expressing HLA B35 and B15. The observed HLA restriction of these overlapping epitopes implies that a tandem of [DRB1*0404-A11(3)] and/or a tandem of [DRB1*0404-B35(15)] might predispose CRS patients to development of IDDM.

Induction of type 1 programmed cell death in U937 cells by the antioxidant, butylated hydroxy-toluene or the free radical spin trap, NTBN

Oxidative stress can initiate programmed cell death and contributes to the patho-physiology of a number of diseases. Low micromolar to millimolar concentrations of various antioxidants or free radical scavengers promote cell growth and reduce cellular suicide induced by several functionally distinct agents, including some known to produce oxidative stress. Severe anoxia or inhibitors of oxidative phosphorylation also initiate programmed cell death. These results seem paradoxical. In order to compare the response of U937 monoblastoid cells to higher concentrations of an antioxidant or a free radical-spin trap, cells were cultured with 20-80 microM concentrations of butylated hydroxy-toluene or with 5 to 60 mM concentrations of the free radical spin trap, N-tertiary butyl phenyl-nitrone. At these concentrations, both agents inhibited cellular proliferation and induced oligosomic DNA, detected by its 'laddering' after electrophoresis on agarose, confirmed by TUNEL (BHT) or flow cytometric (NTBN) evidence of hypodiploid DNA and ultrastructural evidence of a type 1 programmed cell death. The ability of hydroxy-toluenes to oxidize DNA and promote carcinogenesis and whether free radical spin traps could augment or interfere with the response of malignantly transformed cells to chemotherapy or ionizing radiation provide the raison d'etre of these studies.

Free radicals and reactive oxygen species in programmed cell death

Oxidative stress, originating from reactive oxygen species and free radicals provides a constant challenge to eukaryotic cell survival. While implicated in a number of degenerative diseases, some associated with aging and with aging itself, the manner and extent to which oxidative stress contributes to the initiation or implementation of programmed-cell death is problematic. If oxidative stress is an important modulator of programmed-cell death, any ability intentionally to augment or inhibit it might ameliorate diseases in which the process is abnormally underactive or overactive.

Does maximizing programmed cell death necessarily yield an optimum clinical advantage?

Generally it has been believed that a maximum therapeutic induction of programmed cell death in cancer cells is universally desirable. As a corollary, the presence of Bcl-2, a major anti-programmed cell death protein, is considered an unfavorable prognostic sign. The latter is not and the former may not be universally true.