Elevated levels of loneliness in migrant children compared to nonmigrant children in urban China: a systematic review and meta-analysis of comparative studies

PURPOSE OF REVIEW

About one in four children in China is a migrant child. This population has a higher risk of experiencing loneliness. However, existing studies present conflicting findings regarding the levels of loneliness among migrant children as compared to local urban children in urban China. This review performs a meta-analysis of studies comparing loneliness levels between these two groups.

RECENT FINDINGS

A literature search of major Chinese- and English-language databases revealed 27 eligible comparative studies. These studies reported the means and standardized deviations of loneliness scores for both migrant and nonmigrant children in urban China. Meta-analysis results showed that migrant children experienced significantly higher levels of loneliness than their urban nonmigrant counterparts [standardized mean difference (SMD) = 0.21, P  < 0.001]. Subgroup analysis revealed that studies enrolling migrant children from migrant children's schools had significantly higher pooled SMDs than those enrolling children from public schools (0.346 vs. 0.120, P  = 0.047).

SUMMARY

Migrant children in urban China experience higher levels of loneliness compared to their local urban peers. Efforts to create a socially inclusive, migrant-friendly environment and reduce social isolation among migrant children are crucial to help alleviate their feelings of loneliness.

[Long-term outcomes and failure patterns of definitive radiotherapy for cervical esophageal carcinoma]

Objective: To evaluate the long-term outcomes, failure patterns and prognostic factors of definitive radiotherapy in patients with cervical esophageal carcinoma (CEC). Methods: We retrospectively reviewed the clinical data of 148 CEC patients who treated with definitive radiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from January 2001 to December 2017. The median radiation dose was 66 Gy (59.4-70 Gy) and 33.1% of patients received concurrent chemotherapy. The Kaplan-Meier method was used to calculate survival rates. The log rank test was used for survival comparison and univariate prognostic analysis. The Cox model was used for multivariate prognostic analysis. Results: The median follow-up time was 102.6 months. The median survival time, 2- and 5-year overall survival (OS) were 22.7 months, 49.9% and 28.3%. The median, 2- and 5-year progression-free survival were 12.6 months, 35.8% and 25.8%. The 2- and 5-year locoregional recurrence-free survival were 59.1% and 50.8%. The 2- and 5-year distant metastases-free survival were 74.6% and 65.9%. Multivariate analysis showed that EQD(2)>66 Gy was the only independent prognostic indicator for OS (P=0.040). The median survival time and 5-year OS rate significantly improved in patients who received EQD(2)>66 Gy than those who received≤66 Gy (31.2 months vs. 19.2 months, 40.1% vs. 19.1%, P=0.027). A total of 87 patients (58.8%) developed tumor progression. There were 50 (33.8%), 23 (15.5%) and 39 (26.4%) patients developed local, regional recurrence and distant metastases, respectively. Eleven patients (7.4%) underwent salvage surgery, and the laryngeal preservation rate for entire group was 93.9%. Conclusions: Definitive radiotherapy is an effective treatment for cervical esophageal carcinoma with the advantage of larynx preservation. Local recurrence is the major failure pattern. EQD(2)>66 Gy is associated with the improved overall survival.

[Treatment and prognosis analysis of perineural invasion on sinonasal adenoid cystic carcinoma]

Objective: To analyze the efficacy of sinonasal adenoid cystic carcinoma (ACC) with perineural invasion (PNI), and explore the prognostic value of PNI on sinonasal adenoid cystic carcinoma. Methods: The clinical data of 105 patients with sinonasal ACC admitted to Cancer Hospital, Chinese Academy of Medical Sciences from January 2000 to December 2016 were retrospectively reviewed. All patients were restaged according to American Joint Committee on Cancer 8th edition. Follow-up visits were conducted to obtain information of treatment failure and survival outcome. The Log rank test was used for univariate analysis of prognostic factors, and Cox regression model was used for multivariate prognostic analysis. Results: The maxillary sinus (n=59) was the most common primary site, followed by the nasal cavity (n=38). There were 93 patients with stage Ⅲ-Ⅳ. The treatment modalities included surgery alone (n=14), radiotherapy alone (n=13), preoperative radiotherapy plus surgery (n=10), and surgery plus postoperative radiotherapy (n=68). The median follow-up time was 91.8 months, the 5-year local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) rates were 72.6%, 73.0%, 52.9% and 78.0%, respectively. There were 33 patients (31.4%) with PNI-positive. The 5-year DMFS, PFS, and OS rates of PNI-positive group were 53.7%, 29.4% and 56.5%, respectively, which were significantly inferior to those of PNI-negative group (80.8%, 63.0% and 86.8%, respectively, P<0.05), while there was no significant difference in the 5-year LC rate between both groups (64.5% vs 76.5%, P=0.273). The multivariate Cox regression analysis showed PNI was one of the poor prognostic factors of DMFS (HR=3.514, 95%CI: 1.557-7.932), PFS (HR=2.562, 95%CI: 1.349-4.866) and OS (HR=2.605, 95%CI: 1.169-5.806). Among patients with PNI-positive, the 5-year LC, PFS and OS rates of patients received surgery combined with radiotherapy were 84.9%, 41.3% and 72.7%, respectively, which were significantly higher than 23.3%, 10.0% and 26.7% of patients receiving surgery or radiotherapy alone (P<0.05). Conclusion: The presence of PNI increases the risk of distant metastasis in patients with sinonasal ACC. Compared with patients with PNI-negative, the prognosis of patients with PNI-positive is relatively poor, and surgery combined with radiotherapy for PNI-positive sinonasal ACC results in good clinical outcomes.

A175 DISEASE ACTIVITY IN FIRST TRIMESTER IS ASSOCIATED WITH REDUCED GROWTH IN INFANTS BORN TO WOMEN WITH INFLAMMATORY BOWEL DISEASE

Background

Ulcerative colitis (UC) and Crohn’s disease (CD) are chronic inflammatory bowel diseases (IBD) that affect a significant portion of women in childbearing years. It is known that disease activity in early pregnancy negatively impacts obstetrical and perinatal outcomes, but the impact on infant growth is largely unknown.

Aims

The objective of this study was to compare the growth of infants born to women with active IBD during pregnancy versus those born to women with IBD in remission during pregnancy.

Methods

We conducted a prospective cohort study in a Canadian tertiary centre comprised of 98 pregnant women with IBD (63 with UC and 35 with CD) and 13 healthy pregnant women. We collected maternal demographic at trimester 1 and assessed disease activity at each trimester using clinical disease scores and fecal calprotectin. We then collected perinatal outcomes at delivery and followed the infants’ growth and feeding habits up to 12 months of age.

Results

A total of 103 mother-infant pairs were included in the study, of which 88 infants were born to women with IBD, and 15 born to women with active disease at trimester 1. Active disease at trimester 1 was associated with more adverse obstetrical outcomes, reduced 1-minute and 5-minute APGAR scores and more frequent NICU admissions. Infants born to women with active trimester 1 disease had reduced weight-for-age and length-for-age Z scores up to 6 months of age, in the absence of difference in feeding patterns. In addition, women with active disease at trimester 1 had increased expression of IL-8 and IFN-γ compared to those with trimester 1 remission.

Conclusions

Active IBD during first trimester is correlated with decreased infant weight and height up to 6 months of age, suggesting that strict disease control during first trimester, or even preconception, is essential for optimizing infant growth and perinatal outcomes.

Funding Agencies

None

[Prognostic significance of different IDH mutations and accompanying gene mutations in patients with acute myeloid leukemia]

目的

探讨IDH不同突变亚型及伴发不同基因突变在非M₃型急性髓系白血病（AML）患者中的预后意义。

方法

采用二代测序技术检测2016年6月至2018年12月就诊于郑州大学第一附属医院的389例AML患者的22种基因突变情况，通过Kaplan-Meier法及Cox回归模型分析影响预后的因素。

结果

389例AML患者中，IDH1及IDH2的突变率分别为6.2%、8.7%，未发现IDH1与IDH2共突变的情况。IDH2突变型患者年龄偏大、骨髓原始细胞比例高、正常核型多见、常合并RUNX1突变及SRSF2突变。单因素方差分析发现，IDH1突变型组较野生型组的中位总生存（OS）及无进展生存（PFS）时间明显缩短（P值均<0.05）；IDH2突变作为一个单变量对预后无显著影响，不同突变位点对预后的影响不同，IDH2R140突变对预后无显著影响，IDH2R172突变型患者较IDH2野生型患者完全缓解（CR）率明显减低、中位OS及PFS时间明显缩短（P值均<0.05）。在正常核型或年龄≥50岁的患者中，IDH不同突变亚型显示出同样的预后意义。74.1%（43/58）IDH突变患者同时携带其他基因突变，伴发基因突变数目对患者的预后无显著影响，IDH突变患者中伴NPM1突变者的CR率明显高于不伴NPM1突变者（81.8%对36.4%，P＝0.014），伴DNMT3A突变者的中位OS时间短于不伴DNMT3A突变者[4.0（95%CI 3.8～4.2）个月对6.3（95%CI 2.4～10.2）个月，P＝0.041]。多因素分析显示：年龄≥60岁、WBC≥100×10⁹/L是影响患者OS及PFS的独立危险因素，2个疗程内CR、造血干细胞移植是影响患者OS及PFS的独立有利因素。

结论

在AML（非M₃型）患者中，IDH基因突变常与其他基因突变共存，IDH不同突变亚型及伴发基因突变显示出不同的预后意义。

A47 SYNTHETIC HUMAN MILK OLIGOSACCHARIDES PREVENT EXPERIMENTAL NECROTIZING ENTEROCOLITIS VIA DIVERGENT TRANSCRIPTOMIC RESPONSES

Background

Breastmilk reduces the risk of necrotizing enterocolitis (NEC) in preterm infants, but the bioactive components mediating this effect are not well understood. Human milk oligosaccharides (HMOs) reduce NEC both in humans and in relevant animal models. However, it is unclear if there are functional differences between individual oligosaccharides.

Aims

The objective of this study was to compare the intestinal transcriptome responses of individual HMOs using complementary in vitro and in vivo models of NEC.

Methods

RNA sequencing was performed on Caco-2Bbe1 gut epithelial cells after exposure to commercially-purified 2’-fucosyllactose (2’FL), 3-fucosyllactose, 6’-siallyllactose, lacto-N-tetraose (LNT) or lacto-N-neotetraose for 24hr at 37°C for 24 h (n=3). Signaling pathways were analyzed in murine- and human-derived NEC enteroids by qPCR. To validate these findings, five-day-old mouse pups were orally gavaged formula with or without individual HMOs, followed by NEC induction with hypoxia (5% O2, 95% N2) and lipopolysaccharide (4 mg/kg/day). Coded ileal sections (n=6–7/group) were analyzed for mucosal injury by histology, immune fluorescence, immunohistochemistry, and gene expression via qPCR.

Results

The HMO transcriptome clustered into divergent functional categories including metabolic process, protein processing and responses to external stimuli. Each synthetic HMO induced a unique transcriptome and exhibited varying effects on the intestinal epithelial functions and biological pathways. This was confirmed in the murine model of NEC, as both LNT and 2FL mitigated NEC injury with comparable recovery of intestinal cell proliferation (Ki67) and expression of stem cells (Lgr5+). Both qPCR and immunofluorescence staining showed differences between 2FL- and LNT-fed pups in host inflammatory and immune responses.

Conclusions

This study demonstrates that synthetic HMOs ameliorate intestinal injury in experimental NEC. However, the mechanisms by which individual oligosaccharides act on the intestine differ, suggesting that single synthetic HMOs may not fully recapitulate the benefits of pooled HMOs. Future studies will further delineate structure-function relationships of synthetic HMOs on host intestinal innate and adaptive immune responses.

Funding Agencies

CIHRFerring Canada Medical Student Research grant

Lactobacillus rhamnosus strain JB-1 reverses restraint stress-induced gut dysmotility

BACKGROUND

Environmental stress affects the gut with dysmotility being a common consequence. Although a variety of microbes or molecules may prevent the dysmotility, none reverse the dysmotility.

METHODS

We have used a 1 hour restraint stress mouse model to test for treatment effects of the neuroactive microbe, L. rhamnosus JB-1^™ . Motility of fluid-filled ex vivo gut segments in a perfusion organ bath was recorded by video and migrating motor complexes measured using spatiotemporal maps of diameter changes.

KEY RESULTS

Stress reduced jejunal and increased colonic propagating contractile cluster velocities and frequencies, while increasing contraction amplitudes for both. Luminal application of 10E8 cfu/mL JB-1 restored motor complex variables to unstressed levels within minutes of application. L. salivarius or Na.acetate had no treatment effects, while Na.butyrate partially reversed stress effects on colonic frequency and amplitude. Na.propionate reversed the stress effects for jejunum and colon except on jejunal amplitude.

CONCLUSIONS & INFERENCES

Our findings demonstrate, for the first time, a potential for certain beneficial microbes as treatment of stress-induced intestinal dysmotility and that the mechanism for restoration of function occurs within the intestine via a rapid drug-like action on the enteric nervous system.

Spatiotemporal maps reveal regional differences in the effects on gut motility for Lactobacillus reuteri and rhamnosus strains

BACKGROUND

Commensal bacteria such as probiotics that are neuroactive acutely affect the amplitudes of intestinal migrating motor complexes (MMCs). What is lacking for an improved understanding of these motility effects are region specific measurements of velocity and frequency. We have combined intraluminal pressure recordings with spatiotemporal diameter maps to analyze more completely effects of different strains of beneficial bacteria on motility.

METHODS

Intraluminal peak pressure (PPr) was measured and video recordings made of mouse ex vivo jejunum and colon segments before and after intraluminal applications of Lactobacillus rhamnosus (JB-1) or Lactobacillus reuteri (DSM 17938). Migrating motor complex frequency and velocity were calculated.

KEY RESULTS

JB-1 decreased jejunal frequencies by 56% and 34% in colon. Jejunal velocities increased 171%, but decreased 31% in colon. Jejunal PPr decreased by 55% and in colon by 21%. DSM 17938 increased jejunal frequencies 63% and in colon 75%; jejunal velocity decreased 57%, but increased in colon 146%; jejunal PPr was reduced 26% and 12% in colon. TRAM-34 decreased frequency by 71% and increased velocity 200% for jejunum, but increased frequency 46% and velocity 50% for colon; PPr was decreased 59% for jejunum and 39% for colon.

CONCLUSIONS & INFERENCES

The results show that probiotics and other beneficial bacteria have strain and region-specific actions on gut motility that can be successfully discriminated using spatiotemporal mapping of diameter changes. Effects are not necessarily the same in colon and jejunum. Further research is needed on the detailed effects of the strains on enteric neuron currents for each gut region.

Automatic prostate boundary recognition in sonographic images using feature model and genetic algorithm

This paper describes the development of a model-based boundary recognition system for transrectal prostate ultrasonographic images. It consists of two techniques: boundary modeling and boundary searching with model constraints. To achieve higher specificity of the model, a method called feature modeling is derived from the existing point distribution modeling method. To improve the robustness of the searching technique, the genetic algorithm is used. Incremental genetic algorithm with crowding replacement and binary string chromosome type was found experimentally to give good search results. It was shown that the system could recognize the boundary with considerable accuracy and consistency within a few minutes in transrectal ultrasonographic images taken from approximate middle position of the prostate.

The effect of 50 Hz magnetic field on GCSmRNA expression in lymphoma B cell by mRNA differential display

Magnetic fields (MFs) of various characteristics can lead to plethora effects in biological system. From a molecular point of view, we hypothesized that there must be a fundamental difference in gene expression between the MF exposed and the unexposed cell. To identify the classes of genes that are regulated, 0.8 mT 50 Hz MF-induced changes in gene expression were examined in a Daudi cell culture using differential display and reverse transcriptase-polymerase chain reaction. A candidate cDNA (signatured as MF-CB) that was observed in the sham-exposed but not in MF-exposed cultures was recovered and reamplified. After verification by Northern blot, the cDNA was cloned and sequenced. It was found that 254-base pair of 5'-end MF-CB cDNA clone was identical to gcs in open reading frame (ORF) range. Based on the preliminarily sequence, the prolonged length of 5'-end MF-CB cDNA was obtained by PCR amplification and its sequence analysis showed the same results as its original fragment. In order to further determine whether MF-CB cDNA is from gcs, two Northern blots were probed with gcs and MF-CB cDNA, respectively, and the data revealed signals of the same size and expression pattern on the two probe filters, which demonstrated that MF-CB is an EST (expression sequence tag) of gcs. gcs is a gene, identified recently (GenBank accession number D89866), encoding ceramide glucosyltransferase (GCS), which has been implicated as a causal element in human cell growth and differentiation. In an additional experiment, time-dependent changes in the transcription of gcs induced by 0.8 mT MF were observed by Northern blot with a sharp and reproducible inhibition effect after 20 min exposure and a reduction after 20-24 h exposure. The study demonstrates for the first time that 50 Hz MF can lead to changes in gcs transcription, which provides a new clue to elucidate the mechanism by which MF influence cell growth and differentiation.

[Inhibitory effects of tachykinin receptor antagonists on leukotriene C4-induced cardiovascular responses in guinea pigs]

This study is to determine whether sensory neuropeptides are involved in the cardiovascular effects of leukotriene C4 (LTC4). LTC4 (0.8 nmol.kg-1, i.v.) caused hypotensive response and increased Evans blue extravasation from the atria and ventricles in anaesthetized guinea pigs. CP-96345 (2.06 mumol.kg-1, i.v.), a tachykinin NK-1 receptor antagonist, and SR-48968 (1.66 mumol.kg-1, i.v.), an NK-2 receptor antagonist, partially inhibited LTC4-induced increase (46.6% and 37.5%, respectively) of dye extravasation from the atria of guinea pigs. Combination of CP-96345 and SR-48968 markedly inhibited LTC4-induced hypotension and increase of microvascular leakage in both atria and ventricles (58.1% and 54.1%, respectively), similar to the inhibition by ONO-1078 (0.06 mumol.kg-1, i.v.), a specific leukotriene antagonist. These results suggest that NK-1 and NK-2 receptors may be involved in the hypotension and the inflammation of heart induced by LTC4.

The tumor suppressor Smad4/DPC4 and transcriptional adaptor CBP/p300 are coactivators for smad3 in TGF-beta-induced transcriptional activation

Smads regulate transcription of defined genes in response to TGF-beta receptor activation, although the mechanisms of Smad-mediated transcription are not well understood. We demonstrate that the TGF-beta-inducible Smad3 uses the tumor suppressor Smad4/DPC4 and CBP/p300 as transcriptional coactivators, which associate with Smad3 in response to TGF-beta. The association of CBP with Smad3 was localized to the carboxyl terminus of Smad3, which is required for transcriptional activation, and a defined segment in CBP. Furthermore, CBP/p300 stimulated both TGF-beta- and Smad-induced transcription in a Smad4/DPC4-dependent fashion. Smad3 transactivation and TGF-beta-induced transcription were inhibited by expressing E1A, which interferes with CBP functions. The coactivator functions and physical interactions of Smad4 and CBP/p300 with Smad3 allow a model for the induction of gene expression in response to TGF-beta.

Heteromeric and homomeric interactions correlate with signaling activity and functional cooperativity of Smad3 and Smad4/DPC4

Homologs of Drosophila Mad function as downstream mediators of the receptors for transforming growth factor beta (TGF-beta)-related factors. Two homologs, the receptor-associated Smad3 and the tumor suppressor Smad4/DPC4, synergize to induce ligand-independent TGF-beta activities and are essential mediators of the natural TGF-beta response. We now show that Smad3 and Smad4 associate in homomeric and heteromeric interactions, as assessed by yeast two-hybrid and coimmunoprecipitation analyses. Heteromeric interactions are mediated through the conserved C-terminal domains of Smad3 and Smad4. In Smad3, the homomeric interaction is mediated by the same domain. In contrast, the homomeric association of Smad4 requires both the N-terminal domain and the C-terminal domain, which by itself does not homomerize. Mutations that have been associated with impaired Mad activity in Drosophila or decreased tumor suppressor activity of Smad4/DPC4 in pancreas cancer, including a short C-terminal truncation and two point mutations in the conserved C-terminal domains, impair the ability of Smad3 and Smad4 to undergo homo- and heteromeric associations. Analyses of the biological activity of Smad3 and Smad4 and their mutants show that full signaling activity correlates with their ability to undergo efficient homo- and heteromeric interactions. Mutations that interfere with these interactions result in decreased signaling activity. Finally, we evaluated the ability of Smad3 or Smad4 to induce transcriptional activation in yeast. These results correlate the ability of individual Smads to homomerize with transcriptional activation and additionally with their biological activity in mammalian cells.

Mitogenic signaling by Ret/ptc2 requires association with enigma via a LIM domain

The ret/ptc2 papillary thyroid cancer oncogene, an oncogenic form of the c-Ret receptor tyrosine kinase, is the product of a somatic crossover event fusing the dimerization domain of the type Ialpha regulatory subunit of cyclic AMP-dependent protein kinase (RI) with the tyrosine kinase domain of c-Ret. Mitogenic activity of Ret/ptc2 required dimerization via the N terminus of RI and a tyrosine residue located C-terminal to the kinase core of Ret, Tyr-586 (Durick, K., Yao, V. J., Borrello, M. G., Bongarzone, I., Pierotti, M. A. and Taylor, S. S. (1995) J. Biol. Chem. 270, 24642-24645). Using the yeast two-hybrid system, Ret/ptc2 binding proteins were identified, and the sites of interaction with Ret/ptc2 were mapped. The SH2 domains of phospholipase Cgamma and Grb10 were both identified, and binding depended on phosphorylation of Tyr-539 and Tyr-429, respectively. These interactions, however, were not required for mitogenic signaling. The second of the three LIM domains in Enigma (Wu, R. Y., and Gill, G. N. (1994) J. Biol. Chem. 269, 25085-25090) was also identified as a Ret/ptc2 binding domain. Enigma, a 455-residue protein, was discovered based on its interaction with the insulin receptor through the C-terminal LIM domain. Although the association with Enigma required Tyr-586 of Ret/ptc2, the interaction was phosphorylation-independent. In contrast to the SH2 interactions, disruption of the interaction with Enigma abolished Ret/ptc2 mitogenic signaling, suggesting that LIM domain recognition of an unphosphorylated tyrosine-based motif is required for Ret signal transduction.

Pulsed magnetic field from video display terminals enhances teratogenic effects of cytosine arabinoside in mice

Eighty-nine Swiss Webster mice were randomly divided into four groups: a control group, a pulsed magnetic field (PMF) group, a cytosine arabinoside (ara-C, a teratogen) group, and a combined PMF + ara-C group. Mice in the PMF and PMF + ara-C groups were irradiated with a PMF (a sawtooth waveform with 52 microseconds rise time, 12 microseconds decay time, and 15.6 kHz frequency) at a peak magnetic flux density of 40 microT for 4 hours daily on days 6-17 of gestation. The mice in the ara-C and the PMF + ara-C groups were injected intraperitoneally on day 9 of gestation with 10 mg/kg of ara-C. The incidence of resorption and dead fetuses was not affected by PMF but was increased by ara-C injection. The malformation incidence of cleft palate (CP) and/or cleft lip (CL) was significantly higher in all three of the treated groups than in the control group (P < 0.05). If, however, statistical analyses had been done on litters rather than on individual fetuses, they would show that the incidence of CP and/or CL in the PMF group is not significantly greater than that in the control group. A significantly higher incidence of CP and/or CL was found in the PMF + ara-C group (49%) than the ara-C alone group (26.1%). These data suggest that PMF might enhance the development of ara-C-induced CP and/or CL. The incidence of minor variations in skeletal development, including reduction of skeletal calcification and loss of skeleton, was not statistically significant in the PMF group.(ABSTRACT TRUNCATED AT 250 WORDS)

LIM domain recognition of a tyrosine-containing tight turn

Endocytosis of cell surface receptors requires sequence "codes" consisting of tight turn structures with an essential Tyr or Phe residue. To determine mechanisms through which cells recognize this information, we utilized exon 16 of the human insulin receptor in the two-hybrid system to isolate a novel 455-amino acid cytoplasmic protein that contains two LIM domains within its carboxyl terminus. Mutational analyses indicate that one of the Cys-rich Zn2+ binding LIM domains specifically recognizes active but not inactive endocytic codes contained in exon 16. These findings suggest that LIM domain structures in proteins provide molecular recognition of Tyr-containing tight turn structures.

Effects of 2.45-GHz microwave radiation and phorbol ester 12-O-tetradecanoylphorbol-13-acetate on dimethylhydrazine-induced colon cancer in mice

The purpose of this study was to investigate the effects of 2.45 GHz microwave (MW) radiation on dimethylhydrazine (DMH)-induced colon cancer in mice. The subjects were 115 Balb/c mice 4 weeks of age. The animals were divided into group A (control), group B (DMH), group C (DMH+MW), and group D [DMH + 12-O-tetradecanoylphorbol-13- acetate (TPA)]. Radiation (10 mW/cm2) was delivered dorsally with the E field parallel to the mouse's long body axis in an anechoic chamber. Radiations were administered 3 hr daily, 6 days per week, over a period of 5 months. The average SAR was estimated to be 10-12 W/kg. During the course of radiation treatments, DMH was injected once per week. The tumor promoter TPA was administered once per week for 10 weeks, from the third week on, after the initial treatment. The incidence of tumors did not significantly differ between the three test groups (groups B, C, and D; P > 0.25). However, the number of tumors, the size of the tumors, and the incidence of protuberant and infiltrative types in tumor-bearing animals were higher in group D compared to groups B and C (P < 0.05). No difference was found between groups B and C (P > 0.25). The study indicates that 2.45 GHz microwave radiation at 10 mW/cm2 power density did not promote DMH-induced colon cancers in young mice. The study also showed that TPA could accelerate colon tumor production if a tumor was initiated.

Neihumicin, a new cytotoxic antibiotic from Micromonospora neihuensis. II. Structural determination and total synthesis

The structure of neihumicin, a new antibiotic isolated from the fermentation broth of Micromonospora neihuensis Wu, sp. nov., has been determined as (Z)-3,(Z)-6-dibenzylidene-2-methoxy-3,6-dihydropyrazin-5-one based upon spectral evidence and X-ray crystallographic analysis. Its total synthesis has also been achieved.

Neihumicin, a new cytotoxic antibiotic from Micromonospora neihuensis. III. Structure-activity relationships

Structure-cytotoxicity relationships studies have indicated that the C-3 and C-6 disubstituted piperazine-2,5-diones are structurally required for significant cytotoxicity, and the neihumicin-like C-3 and C-6 disubstituted unsymmetrical piperazine derivatives are, in general, more cytotoxic than the corresponding symmetrical piperazine-2,5-diones. Several synthetic analogs including 3,6-di-(2,4,5-trimethoxybenzylidene)piperazine-2,5- dione, 3,6-dibenzylidene-2-ethoxy-3,6-dihydropyrazine-5-one, 3-benzylidene-6-(m-chlorobenzylidene)-2-methoxy-3,6-dihydropyrazine++ +-5-one, have been shown to be more cytotoxic than neihumicin.

Neihumicin, a new cytotoxic antibiotic from Micromonospora neihuensis. I. The producing organism, fermentation, isolation and biological properties

A new cytotoxic and antifungal antibiotic, neihumicin, was isolated from the culture broth of a soil isolate identified as Micromonospora neihuensis Wu, sp. nov. Neihumicin shows in vitro cytotoxicity against KB tissue culture cells (ED50 0.94 micrograms/ml) as well as antifungal activity against Saccharomyces cerevisiae ATCC 9763.

[Carcinoembryonic antigen and immunoglobin in gastric juice in the diagnosis of gastric cancer]

Levels of carcinoembryonic antigen (CEA) and immunoglobin (Ig) in gastric juice of 93 patients with benign and malignant gastric diseases were assayed. The CEA level in gastric cancer patients (55.73 +/- 38.26 ng/ml) was obviously higher than that in peptic ulcer (15.51 +/- 12.09 ng/ml) and superficial gastritis (26.96 +/- 20.17 ng/ml). But no significant difference was found between the CEA levels of gastric cancer and chronic atrophic gastritis (48.66 +/- 31.87 ng/ml). Also, elevated CEA was closely correlated to intestinal metaplasia. The positive rate of Ig was significantly higher in gastric cancer (IgG greater than or equal to 185 ug/ml, IgA greater than or equal to 100 ug/ml) than in benign gastric diseases. Although no correlation is present in the CEA and Ig in gastric juice, the combination of these two methods could improve the diagnostic accuracy. We believe that the two assays are worthy for screening gastric cancer from patients with high risk, and for identifying precancerous lesions.

Antitumor agents LV: Effects of genkwadaphnin and yuanhuacine on nucleic acid synthesis of P-388 lymphocytic leukemia cells

The diterpene esters, genkwadaphnin and yuanhuacine, have been shown to possess significant antileukemic activity in the P-388 screen. The major metabolic effects of the diterpene esters were on DNA and protein synthesis. The effects on DNA synthesis in vitro were evoked at a lower concentration than that required for protein synthesis inhibition. The sites in DNA synthesis which were inhibited were DNA polymerase and purine synthesis. In the latter pathway the enzyme activities inhibited were phosphoribosyl aminotransferase, inosinic acid dehydrogenase, and dihydrofolate reductase. In vivo administration of the diterpene esters at 0.8 mg/kg afforded identical types of effects on purine and DNA synthesis and in addition suppressed histone phosphorylation and reduced the number of surviving tumor cells. The in vivo effects on purine and DNA synthesis were evident as early as 6 and 24 hr after administration of a single dose of the diterpene esters.

Antitumor agents 57. The isolation and structural elucidation of microhelenin-E, a new antileukemic nor-pseudoguaianolide, and microhelenin-F from Helenium microcephalum

Two new nor-pseudoguaianolides, microhelenin-E (1) and -F (2), were isolated from Texas Helenium microcephalum and their structures elucidated on the basis of physicochemical data and spectral evidence. Microhelenin-E demonstrated significant in vitro and in vivo cytotoxic and antileukemic activities against KB tissue cell culture (ED50 = 1.38 microgram/ml) P-388 lymphocytic leukemia growth in BDF1 male mice (T/C-166% at 8 mg/kg/day), respectively.

Antitumor agents. 49 tricin, kaempferol-3-O-beta-D-glucopyranoside and (+)-nortrachelogenin, antileukemic principles from Wikstroemia indica

Bioassay-directed isolation of the antitumor extract of Wikstroemia indica (Thymelaeaceae) has led to the characterization of tricin, kaempferol-3-O-beta-D-glucopyranoside, and (+)-nortrachelogenin as the major antileukemic constituents. In addition, daphnoretin was identified as the potent antitumor principle in vivo against the Ehrlich ascites carcinoma growth in mice.

Antitumor agents XXXVI: Structural elucidation of sesquiterpene lactones microhelenins-A, B, and C, microlenin acetate, and plenolin from Helenium microcephalum

The antitumor sesquiterpene lactones microhelenins-A, B, and C, microlenin acetate, and plenolin were isolated from Helenium microcephalum. The structures and stereochemistry of these lactones were determined by physical methods as well as by chemical transformations and correlations. Microlenin acetate appears to be the first novel dimeric sesquiterpene lactone demonstrated to have significant antileukemic activity.

Antitumor agents XXXVIII: Isolation and structural elucidation of novel germacranolides and triterpenes from Elephantopus mollis

The ethanolic extract of Elephantopus mollis yielded three novel cytotoxic antitumor germacranolides, molephantin, molephantinin, and phantomolin. The extract also yielded three inactive known triterpenes, beta-amyrin acetate, lupeol acetate, and epifriedelanol, as well as stigmasterol. The structure and stereochemistry of the cytotoxic antitumor agents molephantin, molephantinin, and phantomolin were determined on the basis of chemical transformations and spectral evidence. Preliminary in vivo tumor assays indicated that molephantinin and phantomolin were potent inhibitors of Ehrlich ascites carcinoma and Walker 256 carcinosarcoma. Molephantinin also showed significant antileukemic activity in the P-388 lymphocytic leukemia screen.

Antitumor agents. XXXIV: Mechanism of action of bruceoside A and brusatol on nucleic acid metabolism of P-388 lymphocytic leukemia cells

The quassinoids bruceantin, brucein D, brucein E, bruceoside A, and brusatol significantly inhibited P-388 lymphocytic leukemic cell RNA and protein synthesis in tissue culture. However, DNA synthesis inhibition seemed to correlate more directly with the anti-neoplastic activity of these compounds in the in vivo P-338 survival system. In vitro, brusatol and bruceoside A marginally inhibited 10-day P-388 lymphocytic leukemia DNA polymerase, RNA polymerase, thymidylate synthetase, dihydrofolate reductase, phosphoribosyl pyrophosphate aminotransferase, and cathepsin protease activities. In vivo studies demonstrated similar inhibition and elevated cyclic AMP levels, correlating positively with the antineoplastic activity of individual compounds. Purine synthesis was inhibited drastically by brusatol in vivo, and one key inhibition site in purine synthesis was at phosphoribosyl pyrophosphate aminotransferase, the regulatory enzyme. Histone phosphorylation and ribonucleotide reductase activity also were inhibited marginally by brusatol.

Antitumor agents. XXXV: Effects of brusatol, bruceoside A, and bruceantin on P-388 lymphocytic leukemia cell respiration

Brusatol, a quassinoid with potent antineoplastic activity against P-388 lymphocytic leukemia cell proliferation, significantly inhibited P-388 cell hexokinase, phosphofructokinase, malic dehydrogenase, and succinic dehydrogenase. Mitochondrial oxidative phosphorylation, basal, and adenosine diphosphate-stimulated respiration, utilizing succinate and alpha-ketoglutarate as the substrate, was suppressed significantly by in vivo treatment with brusatol. However, brusatol treatment had no effect on liver oxidative phosphorylation. Brusatol greatly increased P-388 cyclic AMP levels but had no effect on liver cyclic nucleotides. Similar inhibitory effects on P-388 cell oxidative phosphorylation were found in vitro with brusatol, bruceoside A, and bruceantin. Brusatol had no effect on adenosine triphosphatase activity or on uncoupling of oxidative phosphorylation. Rather, brusatol appeared to increase the concentration of reduced mitochondrial electron-transport cofactors, thereby blocking aerobic respiration. A proposed mechanism of action is discussed.

Anti-inflammatory activity of sesquiterpene lactones and related compounds

Some sesquiterpene lactones and related compounds were tested for anti-inflammatory activity in rodents. In the edema-induced carrageenan inflammation screen, the alpha-methylene-gamma-lactone moiety of the sesquiterpene lactones was required for inhibitory activity. The 6-hydroxy group of helenalin also was required for potency. In the tenulin series, the 2,3-epoxy derivatives were marginally active. The same structure was required for inhibition of the writhing reflex. In the chronic adjuvant arthritic screen, compounds containing the alpha-methylene-gamma-lactone moiety, the beta-unsubstituted cyclopentenone ring, and the alpha-epoxy cyclopentenone system afforded significant inhibition at 2.5 mg/kg/day. The sesquiterpene lactones were marginally effective against induced pleurisy. The delayed hypersensitivity was suppressed by these agents whereas immunoglobulin synthesis was slightly stimulated. No delerious side effects were observed with these agents from the limited tests performed.

Phage Xp12 of Xanthomonas oryzae (Uyeda et Ishiyama) Dowson

The properties of bacteriophage Xp12 of Xanthomonas oryzae, isolated from the water in a paddy field in Taiwan and found to contain 5-methylcytosine instead of cytosine, were studied. Phage preparations with high purity were obtained by a procedure involving differential centrifugation and density gradient centrifugation in sucrose solution. Electron microscopic studies revealed that this phage had a head of elliptical hexagonal outline which measured 76 × 55 mμ and a tail of 6 × 133 mμ. Phage Xp12 differed both morphologically and serologically from phages Xp10, Xp20, and Xf. The temperature of thermal inactivation for Xp12 was 66 °C. One step growth studies showed that the latent period for Xp12 was 140 minutes and the burst size was 35. According to the base ratio and composition of Xp12 nucleic acid, it was characteristically a highly ordered double-stranded deoxyribonucleic acid.