Visible light-activated photosensitizer inhibits the plasmid-mediated horizontal gene transfer of antibiotic resistance genes

Inhibition of plasmid transfer, including transformation and conjugation, is essential to prevent the spread of plasmid-encoded antimicrobial resistance. Photosensitizers have been successfully used in the treatment of serious infectious diseases, however, the effects of photosensitizers on the plasmid transfer are still elusive. In this study, we determined the transformation and conjugation efficiency of plasmid pUC19 and pRP4, respectively, when exposed to a photosensitizer (Visible Light-activated Rose Bengal, VLRB). The results showed that the activation of VLRB resulted in up to a 580-fold decrease in the transformation frequency of pUC19 and a 10-fold decrease in the conjugation frequency of pRP4 compared with the non-VLRB control. The inhibition of pUC19 transformation by VLRB exhibited a dose-dependent manner and was attributed to the changes in the plasmid conformation. The inhibition of pRP4 conjugation was associated with the generation of extracellular free radicals, induced oxidative stress, suppression of the mating pair formation gene (trbBp) and DNA transfer and replication gene (trfAp), and enhanced expression of the global regulatory genes (korA, korB, and trbA). These findings highlight the potential of visible light-activated photosensitizer for mitigating the dissemination of plasmid-encoded antibiotic resistance genes.

[Review on the progress of tobacco epidemic monitoring methods]

Tobacco use is a major preventable contributor to premature death and disease globally. Tobacco epidemic monitoring plays a vital role in tobacco control, considered an essential component of tobacco control in the WHO Framework Convention on Tobacco Control and MPOWER package of tobacco control. In this paper, we reviewed the methods of tobacco monitoring worldwide, mainly including face-to-face surveys, telephone interviews, online questionnaire surveys, data sharing, model estimation, smoking cessation support, and the combination of multiple methods. Meanwhile, we analyzed the strengths and weaknesses of those monitoring methods. Tobacco monitoring methods vary in countries and regions. The review might provide a reference for tobacco epidemic monitoring in China.

Chemical and mechanical stability of an ion-exchanged lithium disilicate glass in artificial saliva

Multi-component lithium disilicate (LD) glasses were ion-exchanged in a pure or mixed nitrate salt bath. The surface morphologies, mechanical properties, chemical stability and ion leaching of ion-exchanged LD glasses before and after storage in artificial saliva for 21 days were investigated. It can be found that chemical stability of ion-exchanged LD glass was temperature-dependent. The residual compressive stress induced by ion-exchange increased the chemical potential of alkali ions in glass, and the ion-exchanged LD glass, especially 235 °C/64 h group, chemical stability in artificial saliva for 21 days were deteriorated. Back-exchange treatment could relax the stress on the outermost layer of the ion-exchanged LD glass without deteriorating its strengthening effect, and back-exchanged LD glass presented good chemical and mechanical stability in artificial saliva. The results might help to enhance the service stability of ion-exchanged LD glass-ceramics in the oral condition.

ac4C acetylation of RUNX2 catalyzed by NAT10 spurs osteogenesis of BMSCs and prevents ovariectomy-induced bone loss

N-acetyltransferase 10 (NAT10) is the key enzyme for N4-acetylcytidine (ac4C) modification of mRNA, which participates in various cellular processes and is related to many diseases. Here, we explore the relationships among osteoblast differentiation, NAT10, and ac4C, and we found that NAT0 expression and the ac4C level of total RNA were decreased in the bone tissues of bilateral ovariectomized (OVX) mice and osteoporosis patients. Adenoviruses overexpressing NAT10 reversed bone loss, and Remodelin, an NAT10 inhibitor, enhanced the loss of bone mass in OVX mice. Moreover, bone marrow-derived mesenchymal stem cells (BMSCs) with low-level ac4C modification formed fewer calcium nodules in vitro with NAT10 silencing, whereas BMSCs with high-level ac4C modification formed more calcium nodules with NAT10 overexpression. Moreover, we demonstrated that the ac4C level of runt-related transcription factor 2 (RUNX2) mRNA was increased after BMSCs were cultured in osteogenic medium (OM) and decreased after NAT10 silencing. The RUNX2 mRNA half-life and protein expression decreased after silencing NAT10 in BMSCs. Therefore, NAT10-based ac4C modification promotes the osteogenic differentiation of BMSCs by regulating the RUNX2 ac4C level. Because abnormal levels of NAT10 are probably one of the mechanisms responsible for osteoporosis, NAT10 is a new potential therapeutic target for this disease.

[Clinicopathological characteristics and prognosis of patients with sporadic multiple primary gastrointestinal stromal tumors]

Objective: To investigate the clinicopathological characteristics and prognosis of sporadic multiple primary gastrointestinal stromal tumor (GIST). Methods: A retrospective cohort study was conducted. Case inclusion criteria: (1) postoperative pathological diagnosis of GIST; (2) primary GIST with single lesion or sporadic multiple primary GIST (sporadic GIST was defined as primary GIST other than familial and syndrome-related GIST, and multiple primary GIST was defined as the number of primary GISTs in the same patient ≥ 2); (3) patients with complete clinicopathological data. Those with tumor recurrence or distant metastasis, and with other malignancies were excluded. Medical records of patients with primary GIST who underwent surgical resection in the Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2010 to December 2020 were collected. Patients were divided into sporadic multiple primary GIST group and single primary GIST group according to the number of primary GIST lesions. The clinicopathological data and prognosis of the two groups were observed and compared. Results: A total of 1200 patients with primary GIST were enrolled in this study, including 628 males (52.3%) and 572 females (47.7%), with a median onset age of 58 (19-93) years. Among them, 1165 cases (97.1%) were sporadic primary GIST with single lesion; 35 cases (2.9%) were sporadic multiple primary GIST. Among 35 cases of sporadic multiple primary GIST, 3 cases (8.6%) had acid reflux as the first symptom, which was higher than the single primary GIST group (22/1165, 1.9%) (χ(2)=7.437, P=0.006). There were no significant differences in other clinical characteristics between the two groups (all P>0.05). Patients in the sporadic multiple primary GIST group contained a total of 80 primary tumors. Compared with the single primary GIST group, the sporadic multiple primary GIST group had a higher proportion of tumors originating in the stomach [87.5% (70/80) vs. 59.1% (689/1165)], lower proportion of spindle cell in histology [85.0% (68/80) vs. 93.7% (1092/1165)], higher proportion of positive CD34 [97.5% (78/80) vs. 87.6% (1021/1165)], smaller maximum diameter [maximum diameter ≤2.0 cm: 61.2% (49/80) vs. 28.8% (335/1165)], lower mitotic rate [≤5/50 high-power fields (HPF): 93.8% (75/80) vs. 74.5% (868/1165)], lower risk of recurrence [60.0% (48/80) vs. 23.3% (271/1165)], and the differences were all statistically significant (all P<0.05). The 3-year recurrence-free survival rate in the sporadic multiple primary group and the single primary GIST group was 96.6% and 89.3% respectively (P=0.160), and the 3-year overall survival rate was 100.0% and 92.8%, respectively (P=0.088). Conclusions: The most common type of sporadic multiple primary GIST is multiple tumors originating in the stomach at the same time. Compared with primary GIST with single lesion, sporadic multiple primary GIST presents smaller maximum diameter and lower mitotic rate. The prognosis of patients between two groups is not significantly different.

[Species composition and community structure of coniferous-broadleaved mixed forest in Xiaolong Mountain, Gansu Province, Northwest China]

Xiaolong Mountain, located in warm temperate subtropical transition zone, is one of the important biodiversity conservation areas in China. We analyzed species composition, community structure, and habitat preferences of all woody plant species with DBH (diameter at breast height)≥1 cm in a 6 hm² plot in Xiaolong Mountain, Gansu Province, Northwest China. A total of 29251 individuals (41735 stems) belonging to 33 families, 65 genera, and 124 species were recorded. The 28 species with importance value ≥1 contributed 82.9% to the total abundance. The top four species with the highest importance value were Quercus aliena var. acuteserrata, Betula platyphylla, Lindera aggregata var. playfairii and Corylus heterophylla. The structure of DBH size class of all stems showed an inverse 'J' type, indicating a successful regeneration tendency in the understory. Results from the indicator species analysis showed that 11 species had significant habitat prefe-rences, an two species (Ostrya japonica and Acer stachyophyllum subsp. betulifolium) had the most obvious preferences. Results from the redundancy analysis and partial methods showed that topographic factors played a dominant role in determining species distribution.

[Analysis of imatinib trough concentration at steady state in adjuvant therapy of patients with high risk gastrointestinal stromal tumor]

Objective: To explore the features of imatinib mesylate (IM) plasma concentration during adjuvant therapy and clinical factors associated with IM plasma concentration in patients with high risk gastrointestinal stromal tumors (GIST), and to determine whether IM plasma concentration <1100 μg/L influences the efficacy of adjuvant therapy. Methods: A retrospective case control study method was used. Case inclusion criteria: (1) complete resection of lesion and GIST confirmed by pathology; (2) high risk classified according to modified National Institutes of Health classification system (2008); (3) administration of IM 400 mg/d for at least 1 month; (4) not taking the medication likely affecting IM pharmacokinetic, such as rifampicin, dilantin, and carbamazepine, within 1 month before blood collection. Data of GIST patients who visited GIST Disease - Oriented Outpatient, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 2015 to December 2018 were retrospectively analyzed. After taking IM for 22-26 hours, 5 ml of peripheral venous blood was collected into EDTA anticoagulant tube. IM plasma concentration was detected by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Patients were divided into <1100 μg/L group and ≥1100 μg/L group according to plasma concentration. Linear regression was used to analyze the relevance between clinical features and IM plasma concentration. Parameters with normal distribution were analyzed by Pearson correlation coefficient, and parameters with non-normal distribution were analyzed by Spearman correlation. Kaplan-Meier survival curves and COX regression model were used for survival analysis. Results: Among the 85 patients enrolled in the study, 49 patients (57.6%) were male and 36 (42.4%) were female, with mean age of (51.9±11.0) years. The body mass index was (22.5±2.9) kg/m(2) and body surface area was (1.6±0.2) m(2). Thirty patients received gene test, including 23 patients with c-Kit exon 11 mutation, 4 with c-Kit exon 9 mutation, 1 with c-Kit exon 11 and 17 mutation and 2 without c-Kit or PDGFRA gene mutation. The mean IM plasma concentration was (1391.4±631.3) μg/L, and there were 32 patients with plasma concentration <1100 μg/L and 53 patients with plasma concentration ≥1100 μg/L. There were no statistically significant differences between the two groups in gender, age, body mass index, body surface area, hematological examination (white blood cells, albumin, alanine aminotransferase, aspartate aminotransferase and serum creatinine), tumor location, tumor size, mitotic counts, duration of adjuvant therapy and methods of operation (all P>0.05). Positive correlation between IM plasma concentration and serum creatinine was observed in linear regression analysis (r=0.297, P=0.007), but there were no correlations between IM plasma concentration and age (r=0.044, P=0.686), body mass index (r=0.066, P=0.547), body surface area (r=-0.010, P=0.924), white blood cells (r=-0.080, P=0.478), albumin (r=-0.065, P=0.563), alanine aminotransferase (r=0.114, P=0.308), aspartate aminotransferase (r=0.170, P=0.127) and duration of adjuvant therapy (ρ=0.060, P=0.586). There was no statistically significant difference in IM plasma concentration between patients with different genders (t=0.336, P=0.738) and patients with different surgical methods (F=0.888, P=0.451). Up to March 1, 2019. the median follow-up time was 30 (range 4-49) months. Tumor recurrence was detected in two patients with plasma concentration <1100 μg/L and two with plasma concentration ≥1100 μg/L. One recurrent patient with plasma concentration <1100 μg/L was detected to harbor c-Kit exon 11 and exon 17 mutations, and the other did not receive gene detection. Two recurrent patients with plasma concentration ≥1100 μg/L were both detected to harbor c-Kit exon 9 mutation. The 3-year relapse-free survival rate was 96.4% in the cohort, 96.2% in patients with plasma concentration <1100 μg/L, and 96.6% in patients with plasma concentration ≥1100 μg/L. No significant difference in relapse-free survival was observed between the two groups (P=0.204). Univariate Cox analysis showed that IM plasma concentration <1100 μg/L was not a risk factor for patients with high risk GIST (HR=0.238, 95% CI: 0.022-2.637, P=0.242). Conclusions: IM plasma concentration of adjuvant therapy in patients with high risk GIST varies with individual. Patients with higher level of serum creatinine are more likely to have a higher plasma concentration. A blood drug concentration standard of less than 1100 μg/L for advanced GIST patients may not influence the prognosis of patients with high risk GIST.

[Study on the metastatic sequence of cervix lymph node in hypopharyngeal carcinoma]

Objective: To investigate the metastatic sequence of cervical lymph node in hypopharyngeal carcinoma aimed at guiding neck exploration. Methods: Seventy-five serial sections of integrally dissected lateral neck specimens from 67 patients of hypophayryngeal carcinoma were histopathologically observed, and the metastatic sequence of cervical lymph node of hypophayryngeal carcinoma were analysed. Results: In 75 integrally dissected lateral neck specimens, 63 laterals were found to occur cervical lymph node metastases, the metastatic ratio was 84.0%. The analytic result of 63 dissected lateral neck specimens with positive lymph nodes showed that the metastatic lymph node ratio in descending order was level Ⅱ (90.5%), level Ⅲ (76.2%), level Ⅳ (41.3%), level Ⅴ (15.9%), level Ⅰ (7.9%) and level Ⅵ (3.2%). The metastatic ratio of lymph node between level Ⅰ~Ⅵ were significantly different from each other (P<0.01). When the tumor metastasized to one cervical lymph node, this could be found in levels Ⅱ or Ⅲ, when metastasized to two cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, and when metastasized to more than 5 of cervical lymph nodes, these could be found in levels Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅰand Ⅵ. According to the occurring sequence, metastatic ratio and number of cervical lymph node metastasis (LNM), levels Ⅱ and Ⅲ were identified as the first station, level Ⅳ was the second station and levels Ⅴ, Ⅰ and Ⅵ were the third station of cervical LNM in hypopharyngeal carcinoma. Conclusion: The confirmation of metastatic sequence of cervical lymph node in hypophayryngeal carcinoma provides a reliable evidence for neck lymph node dissection and reference value for clinic therapy.

Different dietary energy intake affects skeletal muscle development through an Akt-dependent pathway in Dorper × Small Thin-Tailed crossbred ewe lambs

The objective of this experiment was to investigate the mechanisms through which different levels of dietary energy affect postnatal skeletal muscle development in ewe lambs. Twelve Dorper × Small Thin-Tailed crossbred ewe lambs (100 d of age; 20 ± 0.5 kg BW) were selected randomly and divided into 2 groups in a completely randomized design. Animals were offered identical diets at 100% or 65% of ad libitum intake. Lambs were euthanized when BW in the ad libitum group reached 35 kg and the semitendinosus muscle was sampled. Final BW and skeletal muscle weight were decreased (P < 0.01) by feed restriction. Both muscle fiber size distribution and myofibril cross-sectional area were altered by feed restriction. Insulin-like growth factor 1 (IGF-1) messenger RNA (mRNA) content was decreased (P < 0.05) when lambs were underfed, whereas no difference for IGF-2 mRNA expression was observed (P > 0.05). Feed restriction altered phosphor-Akt protein abundance (P < 0.01). Moreover, the mammalian target of rapamycin (mTOR) pathway was inhibited by feed restriction, which was associated with decreased phosphor-mTOR, phosphorylated eukaryotic initiation factor 4E binding protein 1 (phosphor-4EBP1), and phosphorylated ribosomal protein S6 kinase (phosphor-S6K). Both mRNA expression of myostatin and its protein content were elevated in feed-restricted ewe lambs (P < 0.05). In addition, mRNA expression of both muscle RING finger 1 and muscle atrophy F-box was increased when ewe lambs were underfed. In summary, feed restriction in young growing ewe lambs attenuates skeletal muscle hypertrophy by inhibiting protein synthesis and increasing protein degradation, which may act through the Akt-dependent pathway.

Intrafollicular expression and potential regulatory role of cocaine- and amphetamine-regulated transcript in the ovine ovary

Follicular growth is regulated by a complex interaction of pituitary gonadotropins with local regulatory molecules. Previous studies demonstrated an important role for cocaine- and amphetamine-regulated transcript (CART) in regulation of granulosa cell estradiol production associated with dominant follicle selection in cattle. However, intraovarian expression and actions of CART in other species, including sheep, are not known. The objective of this study was to investigate the expression of CART in sheep follicles and determine the effects of CART on indices of ovine granulosa cell function linked to follicular development. Results demonstrated the expression of CART messenger RNA and prominent intraovarian localization of CART peptide in granulosa cells of sheep follicles. Granulosa cell CART messenger RNA was lower, but follicular fluid estradiol concentrations were higher in large (>5 mm) follicles vs smaller 3- to 5-mm follicles harvested from sheep ovaries of abattoir origin. CART treatment inhibited follicle stimulating hormone-induced estradiol production by cultured ovine granulosal cells and also blocked the follicle stimulating hormone-induced increase in granulosa cell numbers. Results demonstrate expression of CART in sheep follicular tissues and suggest potential biological actions of CART, which are inhibitory to ovine follicular growth and development.

Enhanced ultraviolet emission from Au/Ag-nanoparticles@MgO/ZnO heterostructure light-emitting diodes: A combined effect of exciton- and photon- localized surface plasmon couplings

Localized surface plasmon (LSP)-enhanced ultraviolet light-emitting diodes (LEDs) based on a Au/MgO/ZnO metal/insulator/semi- conductor heterostructure were fabricated by embedding Ag nanoparticles (Ag-NPs) into MgO dielectric layer. A ~6-fold electroluminescence (EL) enhancement was achieved from the Ag-NPs decorated device. Time-resolved spectroscopy studies, as well as analogue simulation and theoretical estimation based on experimental data, reveal that the internal quantum efficiency and light extraction efficiency of the heterojunction LED are increased ~3-fold and ~2-fold, respectively, as a result of the introduction of Ag LSPs. This result indicates that the observed EL enhancement originates from a combined effect of both exciton-LSP coupling and photon-LSP coupling.

A pilot study of endoscopic spray cryotherapy by pressurized carbon dioxide gas for Barrett's esophagus

BACKGROUND AND STUDY AIMS

Endoscopic spray cryoablation is a novel approach for the treatment of Barrett's esophagus. However, few studies have reported its efficacy, especially with the use of carbon dioxide (CO (2)). The aim of the current study was to evaluate the short term efficacy and complications using CO (2) in endoscopic cryoablation of Barrett's esophagus.

METHODS

Patients diagnosed with Barrett's esophagus underwent monthly stepwise cryoablation with pressurized CO (2) gas, with follow-up esophageal biopsies until complete histological reversal was achieved. Responses were analyzed with an intention-to-treat analysis according to complete response for intestinal metaplasia (CR-IM), which was defined as the elimination of all intestinal metaplasia including specialized intestinal metaplasia (SIM), subsquamous SIM, and dysplasia with intestinal metaplasia in the biopsies under narrow-band imaging (NBI).

RESULTS

In total, 22 patients were enrolled, 20 of whom completed the treatment. Two patients declined further ablation after the first cryotherapy session. A total of 44 sessions were performed; a median of 2 sessions per patient (range 1 - 3 sessions) were needed to complete the ablation of Barrett's esophagus. No severe complications occurred. Follow-up endoscopies were performed in 20 patients (90.9 %). Two patients (9.1 %) were lost to follow-up. Median follow-up was 10 months (range 6 - 18 months). After cryotherapy, 20 patients (90.9 %) reached CR-IM of Barrett's esophagus. Patients underwent a median number of 3 follow-up endoscopies (range 2 - 4) with biopsies. At 6 months, recurrence was evident in three patients (13.6 % of the overall population, 15.0 % of the CR-IM population). One of the three patients developed intestinal metaplasia but no dysplastic change and the other two developed subsquamous SIM.

CONCLUSIONS

The pressurized CO (2) spray cryotherapy is a relatively effective and safe endoscopic treatment for Barrett's esophagus.

Proteomic identification of OsCYP2, a rice cyclophilin that confers salt tolerance in rice (Oryza sativa L.) seedlings when overexpressed

BACKGROUND

High Salinity is a major environmental stress influencing growth and development of rice. Comparative proteomic analysis of hybrid rice shoot proteins from Shanyou 10 seedlings, a salt-tolerant hybrid variety, and Liangyoupeijiu seedlings, a salt-sensitive hybrid variety, was performed to identify new components involved in salt-stress signaling.

RESULTS

Phenotypic analysis of one protein that was upregulated during salt-induced stress, cyclophilin 2 (OsCYP2), indicated that OsCYP2 transgenic rice seedlings had better tolerance to salt stress than did wild-type seedlings. Interestingly, wild-type seedlings exhibited a marked reduction in maximal photochemical efficiency under salt stress, whereas no such change was observed for OsCYP2-transgenic seedlings. OsCYP2-transgenic seedlings had lower levels of lipid peroxidation products and higher activities of antioxidant enzymes than wild-type seedlings. Spatiotemporal expression analysis of OsCYP2 showed that it could be induced by salt stress in both Shanyou 10 and Liangyoupeijiu seedlings, but Shanyou 10 seedlings showed higher OsCYP2 expression levels. Moreover, circadian rhythm expression of OsCYP2 in Shanyou 10 seedlings occurred earlier than in Liangyoupeijiu seedlings. Treatment with PEG, heat, or ABA induced OsCYP2 expression in Shanyou 10 seedlings but inhibited its expression in Liangyoupeijiu seedlings. Cold stress inhibited OsCYP2 expression in Shanyou 10 and Liangyoupeijiu seedlings. In addition, OsCYP2 was strongly expressed in shoots but rarely in roots in two rice hybrid varieties.

CONCLUSIONS

Together, these data suggest that OsCYP2 may act as a key regulator that controls ROS level by modulating activities of antioxidant enzymes at translation level. OsCYP2 expression is not only induced by salt stress, but also regulated by circadian rhythm. Moreover, OsCYP2 is also likely to act as a key component that is involved in signal pathways of other types of stresses-PEG, heat, cold, or ABA.

Duodenal gastric metaplasia and Helicobacter pylori infection in patients with diffuse nodular duodenitis

Whether the regression of gastric metaplasia in the duodenum can be achieved after eradication of Helicobacter pylori is not clear. The aim of the present study was to investigate the relationship between H. pylori infection and gastric metaplasia in patients with endoscopic diffuse nodular duodenitis. Eighty-six patients with endoscopically confirmed nodular duodenitis and 40 control patients with normal duodenal appearance were investigated. The H. pylori-positive patients with duodenitis received anti-H. pylori triple therapy (20 mg omeprazole plus 250 mg clarithromycin and 400 mg metronidazole, all twice daily) for one week. A control endoscopy was performed 6 months after H. pylori treatment. The H. pylori-negative patients with duodenitis received 20 mg omeprazole once daily for 6 months and a control endoscopy was performed 2 weeks after treatment. The prevalence of H. pylori infection was 58.1%, and the prevalence of gastric metaplasia was 57.0%. Seventy-six patients underwent endoscopy again. No influence on the endoscopic appearance of nodular duodenitis was found after eradication of H. pylori or acid suppression therapy. However, gastric metaplasia significantly decreased and complete regression was achieved in 15/28 patients (53.6%) 6 months after eradication of H. pylori, accompanied by significant improvement of other histological alterations. Only mild chronic inflammation, but not gastric metaplasia, was found in the control group, none with H. pylori infection in the duodenal bulb. Therefore, H. pylori infection is related to the extent of gastric metaplasia in the duodenum, but not to the presence of diffuse nodular duodenitis.

An efficient field screening procedure for identifying transposants for constructing an Ac/Ds-based insertional-mutant library of rice

An efficient system was developed, and several variables tested, for generating a large-scale insertional-mutagenesis population of rice. The most important feature in this improved Ac/Ds tagging system is that one can conveniently carry out large-scale screening in the field and select transposants at the seedling stage. Rice was transformed with a plasmid that includes a Basta-resistance gene (bar). After the Ds element is excised during transposition, bar becomes adjacent to the ubiquitin promoter, and the rice plant becomes resistant to the herbicide Basta. In principle, one can plant up to one million plants in the field and select those plants that survive after spraying with Basta. To test the utility of this system, 4 Ds starter lines were crossed with 14 different Ac plants, and many transposants were successfully identified after planting 134 285 F2 plants in the field. Over 2 800 of these transposants were randomly chosen for PCR analysis, and the results fully confirmed the reliability of the field screening procedure.

Helicobacter pylori associated gastric diseases and lymphoid tissue hyperplasia in gastric antral mucosa

AIM

To investigate the relation between Helicobacter pylori associated gastroduodenal diseases and lymphoid tissue hyperplasia in the antral mucosa and to pursue its evolution after eradication of H pylori.

METHODS

Gastric antral biopsy specimens were obtained from 438 patients with H pylori positive gastroduodenal diseases (185 chronic gastritis, 69 gastric ulcer, and 184 duodenal ulcer) and 50 H pylori negative healthy controls. Lymphoid follicles and aggregates were counted and other pathological features were scored according to the updated Sydney system for classification of chronic gastritis. After a course of anti-H pylori treatment, biopsy specimens were obtained at four to six weeks, 12 months, and 24 months in the chronic gastritis patient group.

RESULTS

The total prevalence of lymphoid follicles and aggregates in the biopsies was 79.9% (350 of 438; 95% confidence intervals (CI), 0.76 to 0.84). The prevalence and density of lymphoid follicles and aggregates were significantly different in the various gastroduodenal diseases. The highest prevalence (89.9%; 95% CI, 0.83 to 0.97) and density (0.82) of lymphoid follicles and aggregates occurred in patients with gastric ulcers. The lowest prevalence of lymphoid follicles and aggregates was found in patients with chronic gastritis (74.6%; 95% CI, 0.68 to 0.81), and the lowest density of lymphoid follicles and aggregates (0.56) was seen in patients with duodenal ulcers. The prevalence and density of lymphoid follicles and aggregates correlated strongly with the activity and severity of gastric antral mucosal inflammation. The eradication of H pylori resulted in a decrease in the prevalence and density of lymphoid follicles and aggregates.

CONCLUSION

The prevalence and density of lymphoid follicles and aggregates in gastric antral mucosal biopsies correlated closely with H pylori infection.

[Histochemical localization and quantitative analysis of anthraquinones in rhizome of Polygonum cuspidatum]

Anthraquinones were histochemically locayed and content were determined in rhizome of Polygonum cuspidatum. Anthraquinones were located in the parenchyma cells of rhizome, including vascular ray, part of parenchyma cell in phloem, cortex and pith. Phelloderm and ray initial also accumulated a small amount anthraquinones. The content of total anthraquinones was highest in pith that consisted of parenchyma cells, and higher in bark (including phloem, cortex and periderm) than in xylem. The content of total anthraquinones was highest in three-year-old rhizome, and higher in biennial rhizome than in annual rhizome. It suggests that correlation exist between accumulation of anthraquinones and the growth age of rhizome.

Photosensitization of hypomycin B--a novel perylenequinonoid pigment with only one intramolecular hydrogen bond

Electron spin resonance technique and spin-trapping methods were used to determine the photoproduction of 1O2 and O2.- by hypomycin B (HMB), a novel perylenequinonoid pigment (PQP) possessing only one hydroxyl group. It was found that the yields of 1O2 and O2.- for HMB were comparable to those for hypocrellin A, a typical natural PQP with good photosensitivity. In addition, the absorption and fluorescence spectra for HMB were investigated. The pKa values in the ground and excited states of HMB were determined to be 8.94 and 5.54, respectively. Thus, the photodynamic mechanisms of HMB may involve not only the photogeneration of 1O2 and O2.- but also the light-induced acidification. Consequently, HMB is proposed to be a good photodynamic therapeutic agent.

[Structural elucidation of a new perylenequinone]

AIM

To study the chemical constituents from the mycelia of Hypomyces sp.

METHODS

Silica gel column chromatography was employed for the isolation and purification. The structure of compound 1 was elucidated on the basis of spectral analysis.

RESULTS AND CONCLUSION

A new perylenequinone, named hypomycin B 1, was isolated from the mycelia of Hypomyces sp.

[Studies on chemical constituents from Euphorbia fischeriana Steud]

OBJECTIVE

To study the chemical constituents of ethanol extract from dried roots of Euphorbia fischeriana.

METHOD

Compounds were separated by column chromatography with silca gel and elucidated by chemical evidence and spectral analysis.

RESULT

Isobauerenyl acetate, beta-amyrin acetate, 24-methylenecycloartenone,octacosyl ferulate and 2,4-dihydroxy-6-methoxy-3-methyl acetophenone were isolated and elucidated.

CONCLUSION

All the compounds were isolated from the plant for the first time.

[A multiple-channel system for synchronous acquisition and analysis of neural electrophysiological signals]

The technique for synchronous electrophysiological recording from multiple single cells has been widely applied, but there is still a shortage of suitable data acquisition and analysis systems to fit electrophysiological equipment made in China or Japan. Recently we have developed an acquisition and analysis system for multiple-channel electrophysiological recording. In this paper, we present the pivotal technique of the system and some examples of applications.

A multicentre study on eradication of Helicobacter pylori using four 1-week triple therapies in China

BACKGROUND

Short-term proton pump inhibitor-based triple therapies for the eradication of Helicobacter pylori are used widely. The eradication rates vary greatly from country to country and from region to region.

AIM

To assess the efficacy at eradicating H. pylori of 1-week regimens containing three medications: omeprazole (O) or colloidal bismuth subcitrate (B), furazolidone (F) or metronidazole (M), and amoxicillin (A) or clarithromycin (C).

METHODS

A multicentre study involving 20 hospitals in different regions of China. A total of 892 patients with H. pylori-positive non-ulcer dyspepsia or healed duodenal ulcer confirmed by endoscopy were recruited to receive, randomly, one of four regimens: OMC, OFC, OFA, and BFC, b.d. for 7 days. 13C-urea breath test was performed 4-8 weeks after completion of treatment.

RESULTS

The eradication rates with per protocol/intention-to-treat analyses were: OMC (n=217/219) 66%/65%; OFC (n=227/229) 69%/69%; OFA (n=223/225) 87%/86%; and BFC (n=214/219) 80%/78%. The eradication rate (per protocol analysis) in duodenal ulcer (79%) was higher than that in non-ulcer dyspepsia (73%, P=0.033). Patient compliance was good. The adverse events of the four regimens were mild, and mainly gastrointestinal.

CONCLUSIONS

The omeprazole, furazolidine and amoxicillin regimen achieves a high H. pylori eradication rate in different geographical regions of China.

[The long-term effect of augmentation rhinoplasty with silicone]

OBJECTIVE

To evaluate the long-term effect of augmentation rhinoplasty with silicone.

METHOD

360 patients underwent augmentation rhinoplasty with silicone. Improved "L" shaped implants were used in 343 patients.

RESULT

Among 360 patients, 334 cases were successful enough (92.83%).

CONCLUSION

The key to the maintenance of the long-term effect is to use properly improved "L"-shaped implant, to choose a suitable tunnel, to prevent various complications and to ask patient's opinions for implant design.

A new quadruple therapy for Helicobacter pylori using tripotassium dicitrato bismuthate, furazolidone, josamycin and famotidine

BACKGROUND

In our previous study, a triple therapy using tripotassium dicitrato bismuthate (TDB), josamycin and furazolidone achieved a suboptimal cure rate of Helicobacter pylori infection.

AIM

To investigate whether the addition of an antisecretory agent raises the cure rate using this regimen.

METHODS

One hundred and twenty H. pylori positive patients with peptic ulcer disease or functional dyspepsia were randomly assigned to receive 1-week quadruple therapy of TDB 240 mg b.d., furazolidone 100 mg b.d., josamycin 1000 mg b.d. and famotidine 20 mg b.d. (BFJF group), or triple therapy of TDB 240 mg b.d., furazolidone 100 mg b.d. and clarithromycin 250 mg b.d. (BFC group). H. pylori status was assessed by histology and culture of gastric biopsy specimens before and at least 4 weeks after completion of therapy.

RESULTS

Seven patients (three in the BFJF group and four in the BFC group) dropped out. Eradication rates (intention-to-treat/per protocol) were 90%/95% in the BFJF group and 82%/88% in the BFC group, respectively (P > 0.05). Duodenal ulcer healing rates were 94% (16/17) in the BFJF group and 80% (20/25) in the BFC group, respectively (P > 0.05). Mild side-effects occurred in 11 (18%) patients in the BFJF group and 10 (17%) in the BFC group (P > 0.05).

CONCLUSIONS

One-week quadruple therapy consisting of TDB, furazolidone, josamycin and famotidine achieves a high cure rate of H. pylori infection.

[A recombinant fowlpox virus expressing the fusion protein of Newcastle disease virus strain F48E8 and its protective efficacy]

The transfer vector pFGF1175-1 was constructed by insertion the fusion protein gene of Newcastle disease virus (NDV) F48E8 strain into the insertion vector pFG1175-1, downstream of P7.5 promotor, and then transfected chicken embryo fibroblast (CEF) cell cultures which had been infected with fowlpox virus (FPV) Chinese vaccine strain 282E4 for 3-4 hours. Recombinant FPV with blue plaques were selected and purified in CEF cell culture laid agar containing X-gal. The recombinant FPV named rFPV-NDF was confirmed expressing NDV fusion protein by indirect immunofluorescence assay, and could protect chickens against virulent NDV challenge, The protective rate was 96.7%.

Furazolidone-containing short-term triple therapies are effective in the treatment of Helicobacter pylori infection

BACKGROUND

A furazolidone-containing therapeutic regimen for Helicobacter pylori infection has attracted special interest in the face of a rising world-wide metronidazole resistant H. pylori, and the expense of currently used antimicrobial regimens.

AIM

To evaluate the efficacy of furazolidone-containing regimens in eradicating H. pylori.

METHODS

One-hundred and forty H. pylori positive patients with endoscopically confirmed duodenal ulcer or functional dyspepsia received one of four different regimens to eradicate H. pylori. In the first trial, the patients were randomly assigned to receive a 1-week course of furazolidone 100 mg b.d. and clarithromycin 250 mg b.d., with either tripotassium dicitrato bismuthate (TDB) 240 mg b.d. (FCB group) or lansoprazole 30 mg daily (FCL group). In the second trial, the patients were randomly assigned to receive a 1-week course of clarithromycin 250 mg b.d. and omeprazole 20 mg daily, with either furazolidone 100 mg b.d. (FCO group) or metronidazole 400 mg b.d. (MCO group). Endoscopy was repeated 4 weeks following completion of therapy with re-assessment of H. pylori status on gastric biopsies by histology and culture.

RESULTS

Four patients (1 in FCB, 1 in FCO and 2 in MCO groups) dropped out because they refused a follow-up endoscopy. Eradication rates of H. pylori on an intention-to-treat basis in the FCB, FCL, FCO and MCO groups were 91% (32/35, 95% CI: 82-99%), 91% (32/35, CI: 82-99%), 86% (30/35, CI: 74-97%) and 74% (26/35, CI: 60-89%) (all P > 0.05), respectively. Mild side-effects occurred in 15% of the 140 patients. In MCO group, the eradication rate in the patients infected with metronidazole-sensitive isolates of H. pylori was 86%, but dropped to 67% in those with metronidazole-resistance strains (P = 0.198).

CONCLUSION

One-week regimens containing furazolidone and clarithromycin in combination with TDB or a proton pump inhibitor fulfil the criteria for successful H. pylori therapy.

High cure rate of Helicobacter pylori infection using tripotassium dicitrato bismuthate, furazolidone and clarithromycin triple therapy for 1 week

BACKGROUND

When metronidazole is used in bismuth-based or proton pump inhibitor-based triple therapy, the cure rate of Helicobacter pylori is usually high. However, metronidazole-resistant H. pylori strains, which are increasing in frequency, are a major cause of failed H. pylori eradication.

AIM

To evaluate the efficacy of non-metronidazole containing bismuth-based triple therapy for H. pylori infection.

METHODS

One-hundred and eighty H. pylori-positive patients with endoscopically documented peptic ulcer disease or functional dyspepsia were randomly assigned to one of three 1-week regimens containing tripotassium dicitrato bismuthate (also called colloidal bismuth subcitrate) 240 mg b.d. and two antibiotics: furazolidone 100 mg b.d. plus clarithromycin 250 mg b.d. (Group A); or clarithromycin 250 mg b.d. plus amoxycillin 1000 mg b.d. (Group B); or furazolidone 100 mg b.d. plus josamycin 1000 mg b.d. (Group C). H. pylori status was assessed by rapid urease test, histology and culture of gastric biopsy specimens taken from both the antrum and corpus, both before and at least 4 weeks after completion of therapy.

RESULTS

Thirteen patients dropped out (3 in group A, 5 in group B and 5 in group C). Based on an intention-to-treat analysis, the eradication rates achieved in groups A, B and C were 88% (53/60), 58% (35/60) and 77% (46/60), respectively. These differences were significant between groups A and B (P < 0.001), as well as between groups B and C (P < 0.05). Side-effects occurred in 7 (12%) patients in group A, 3 (5%) in group B and 8 (13%) in group C, and were mild, with the exception of vomiting in one patient (group C) that resulted in withdrawal from the study.

CONCLUSION

One-week triple therapy, consisting of tripotassium dicitrato bismuthate, low-dose furazolidone and low-dose clarithromycin, achieves a high cure rate of H. pylori.

Modulation of hepatitis C virus quasispecies heterogeneity by interferon-alpha and ribavirin therapy

To determine the effects of interferon-alpha (IFN-alpha) and ribavirin therapy on hepatitis C virus (HCV) quasispecies heterogeneity, 29 patients with chronic HCV infection treated with either IFN-alpha (n = 15), ribavirin (n = 7) or placebo (n = 7) were studied. HCV quasispecies heterogeneity was determined by single-strand conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1). For patients receiving IFN-alpha, HVR1 was amplified in 14 of 15 patients before, and in six of seven patients after therapy. After controlling the amount of amplicon loaded, a reduction in the number of SSCP bands was observed with IFN-alpha therapy (median number of SSCP bands per patient was eight before therapy and two after therapy). In the seven patients within each of the ribavirin- and placebo-treated groups, there was no significant difference in the viraemia level, number of SSCP bands per patient or the SSCP band pattern, before and after therapy. These findings suggest that at the doses given, IFN-alpha, but not ribavirin, exerts a selective pressure on HCV quasispecies heterogeneity.

Seroprevalence of Helicobacter pylori infection in medical staff in Shanghai

BACKGROUND

The epidemiology of Helicobacter pylori is still under investigation. It is postulated that the human stomach is the natural reservoir and that spread occurs by oral-oral or fecal-oral transmission. The aim of this study was to determine whether medical staff, especially endoscopy unit personnel, are at an increased risk of acquiring H. pylori infection.

METHODS

An enzyme-linked immunosorbent assay technique was used to detect circulating H. pylori IgG antibodies in 1050 medical staff from 16 hospitals in Shanghai, including 125 GI endoscopists, 45 endoscopy unit nurses, 71 gastroenterologists not doing endoscopy, 105 nurses working in gastroenterology wards, 417 internists, and 287 general nurses. This group was compared with an age-matched population obtained from the same urban area of the city.

RESULTS

The overall prevalence of H. pylori infection in total medical staff was 70.0%, compared to 44.6% in general population (P < 0.0001). Age-adjusted comparisons between subgroups of medical staff were made. The prevalence of H. pylori in GI endoscopists was 82.4%, which is significantly higher than 66.4% in internists and 65.8% in general nurses (all, P < 0.01) but not significantly different from 77.7% in endoscopy unit nurses or from 74.2% in nurses working in gastroenterology wards (all, P > 0.05). Further analysis did not show any significant difference in the prevalence of H. pylori between other subgroups. The prevalence of H. pylori infection in GI endoscopists increased with the number of years of practice.

CONCLUSIONS

Medical staff, especially endoscopy unit personnel, are at increased risk of infection with H. pylori. These findings strongly suggest the medical practice and endoscopy procedures are risk factors for H. pylori infection and support person-to-person transmission in this setting, probably from patients to medical staff.

Machine learning techniques in early screening for gastric and oesophageal cancer

A database on 2692 dyspeptic patients over the age of 40 was established, consisting of 73 epidemiological and clinical variables. A tree-based machine learning algorithm (PREDICTOR) was applied to this database, in order to attempt to find rules which would classify patients into 2 groups, i.e., those suffering from gastric or oesophageal cancer, and the remainder. The results were encouraging. The cross-validated classification performance figure showed that by classifying 61.3% of the patients as high risk, a sensitivity of 94.9% and a specificity of 39.8% could be achieved. It is planned to construct an expert system based on the rules produced by the machine learning algorithm, in order to provide preliminary screening for cancer in dyspeptic patients.

A single amino acid change in Escherichia coli glycerol kinase abolishes glucose control of glycerol utilization in vivo

Escherichia coli glycerol kinase (EC 2.7.1.30; ATP:glycerol 3-phosphotransferase) is a key element in glucose control of glycerol metabolism. Its catalytic activity is inhibited allosterically by the glycolytic intermediate, fructose 1,6-biphosphate, and by the phosphotransferase system phosphocarrier protein, IIIGlc (also known as IIAGlc). These inhibitors provide mechanisms by which glucose blocks glycerol utilization in vivo. We report here the cloning and sequencing of the glpK22 gene isolated from E. C. C. Lin strain 43, a strain that shows the loss of glucose control of glycerol utilization. DNA sequencing shows a single missense mutation that translates to the amino acid change Gly-304 to Ser (G-304-S) in glycerol kinase. The effects of this substitution on the functional and physical properties of the purified mutant enzyme were determined. Neither of the allosteric ligands inhibits it under conditions that produce strong inhibition of the wild-type enzyme, which is sufficient to explain the phenotype of strain 43. However, IIIGlc activates the mutant enzyme, which could not be predicted from the phenotype. In the wild-type enzyme, G-304 is located 1.3 nm from the active site and 2.5 nm from the IIIGlc binding site (M. Feese, D. W. Pettigrew, N. D. Meadow, S. Roseman, and S. J. Remington, Proc. Natl. Acad. Sci. USA 91:3544-3548, 1994). It is located in the same region as amino acid substitutions in the related protein DnaK which alter its catalytic and regulatory properties and which are postulated to interfere with a domain closure motion (A. S. Kamath-Loeb, C. Z. Lu, W.-C. Suh, M. A. Lonetto, and C. A. Gross, J. Biol. Chem. 270:30051-30059, 1995). The global effect of the G-304-S substitution on the conformation and catalytic and regulatory properties of glycerol kinase is consistent with a role for the domain closure motion in the molecular mechanism for glucose control of glycerol utilization.

The mode of action of hirsutellin A on eukaryotic cells

A 16-kDa protein toxin was purified from Hirsutella thompsonii var thompsonii and named hirsutellin A (HtA). At 0.5 and 5.0 microM concentrations, HtA caused detectable cytopathic effects on Spodoptera frugiperda cells (Sf-9) within 2-4 hr and completely inhibited Sf-9 cell growth at 4 days posttreatment. Electron microscope data showed that the HtA treated Sf-9 cells became hypotrophied and internal organelles and cell membranes were disrupted. At the same concentration, HtA effectively inhibited Brome mosaic virus protein synthesis of both rabbit reticulocyte and wheat germ in vitro translation system. The ribosomal RNA extracted from HtA treated Sf-9 cells produced a smaller RNA (approximately 528 bases) than untreated Sf-9 cells. In summary, HtA is the first mycotoxin of a invertebrate mycopathogen determined to possess ribosomal inhibiting activity and appears to possess some specificity to invertebrate cells.

Extraction and characterization of the insecticidal toxin hirsutellin A produced by Hirsutella thompsonii var. thompsonii

Hirsutellin A (HtA) produced by Hirsutella thompsonii var. thompsonii (strain JAB-04) was extracted and purified using a combination of ion-exchange, gel-permeation, and immunoaffinity chromatography. The identity of the purified HtA was confirmed by amino acid analysis and N-terminal sequencing. Monoclonal antibodies prepared against HtA were capable of detecting 25-50 ng of HtA by direct sandwich ELISA. In addition, utilizing Western blot methods, the antibodies were shown to be specific to HtA. The production of HtA was monitored during submerged fermentation. The peak level of exocellular HtA (13-14 micrograms/ml) was during the late exponential growth phase (39-45 h), determined by utilizing a combination of densitometric analysis of the 16.3-kDa bands on SDS-PAGE gels and ELISA. HtA production was directly correlated with mycelial growth. Twenty-one-hour culture filtrates were highly toxic to larvae of the greater wax moth. Pure HtA at a final concentration of 40 pmol was highly toxic to Galleria mellonella larvae.

An adoption study comparing the prevalence of psychiatric illness in women who have adoptive and natural children compared with women who have adoptive children only

The current study compares the current and lifetime prevalence of affective disorder in women who have adopted and have natural children (n = 110) with women who only have adopted children (n = 176). There was no difference in lifetime prevalence of psychiatric disorder between the two groups and a nonsignificant trend for women who had born children to have had a major depressive episode during their lifetime 48 (44%) cf 62 (35%). The increased prevalence of psychiatric illness in married women with children cannot be explained by the biological fact of bearing children. None of the social variables related to child-rearing which were examined influenced the lifetime prevalence of psychiatric disorder.

Localization of a cycloheximide-sensitivity response element in the human thymidine kinase gene promoter

In order to localize the segment of the human thymidine kinase (TK) gene promoter that mediates sensitivity of TK mRNA expression to the presence of cycloheximide (CX), a series of promoter truncation mutants was prepared between the 460-base pair (bp) promoter that was demonstrated previously to be sensitive to CX and the 83-bp promoter that was demonstrated previously to be insensitive to CX. TK promoters containing 370, 300, 160, or 130 bp of 5'-flanking sequence were all sensitive to inhibition by CX. Further truncation to 100 bp of 5'-flanking sequence eliminated CX sensitivity. Electrophoretic mobility shift assays using a probe containing most of this region (but omitting the SP1 binding site at the 5'-end of the 130-bp promoter) identified some complexes whose formation was sensitive to the presence of CX. Comparison of the sequences of oligonucleotides that were able to compete for formation of mobility shift complexes identified the sequence GCGGCC as a putative CX-sensitivity response element. Two such sequences are found between 83 and 130 bp 5' of the TK capsite. Mutation of the distal sequence attenuated sensitivity of TK mRNA expression to CX, while mutation of the proximal sequence had minimal effect on CX sensitivity. Thus, these data have localized a CX-sensitivity response element to a segment of TK promoter about 120 bp 5' of the capsite that includes the hexamer GCGGCC.

Escherichia coli glycerol kinase: role of a tetramer interface in regulation by fructose 1,6-bisphosphate and phosphotransferase system regulatory protein IIIglc

Escherichia coli glycerol kinase (EC 2.7.1.30; ATP:glycerol 3-phosphotransferase) is a key element in a signal transduction pathway that couples expression of genes required for glycerol metabolism to the relative availability of glycerol and glucose. Its catalytic activity is inhibited by protein-protein interactions with IIIglc, a phosphotransferase system protein, and by fructose 1,6-bisphosphate (FBP); each of these allosteric effectors constitutes a positive signal that glucose is available. Loss of glucose inhibition of glycerol metabolism was used to screen for regulatory mutants of glycerol kinase after hydroxylamine mutagenesis of the cloned glpK gene. Two mutant enzymes were identified and shown by DNA sequencing to contain the mutations alanine 65 to threonine (A65T) and aspartate 72 to asparagine (D72N). Initial velocity studies show the mutations do not significantly affect the catalytic properties, hence active-site structures, of the enzymes. Both mutations decrease inhibition by FBP; A65T eliminates the inhibition while D72N appears to decrease the affinity for FBP and the extent of the inhibition. However, neither mutation significantly affects inhibition by IIIglc. Gel-permeation chromatography studies show that both of the mutations alter the dimer-tetramer assembly reaction of the enzyme and the effect of FBP in increasing the molecular weight. The effects of the mutations on the assembly reaction are consistent with the locations of these two amino acid residues in the X-ray structure, which shows them to be associated with an alpha-helix that constitutes one of the two subunit-subunit interfaces within the tetramer.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of Equisetum hyemale on experimental hyperlipemia in rats and its toxic test]

The results of an experimental study in rats fed with Equisetum hyemale and hyperlipid food have proved that inhibiting effects on the elevation of triglyceride and cholesterol can be obviously observed in both high and low doses of Equisetum. The study also shows that Equisetum hyemale can antagonize the hyperlipemia in rats. The acute toxic test has proved its low toxicity.

[A study on motility of sphincter of Oddi in postcholecystectomy syndrome]

Endoscopic manometry of sphincter of Oddi (SO) and serum levels of gastrin, glucagon, and somatostatin were measured in patients with postcholecystectomy syndrome (n = 12), asymptomatic cholecystectomy patients (n = 6), and controlled subjects (n = 14). Pentagastrin-stimulated gastric acid secretion test was also performed in part of patients who had symptoms or no symptoms after the removal of gallbladder. The results showed that the patients of symptomatic group had hypertonic dyskinesia of SO as shown by deep and wide waves superimposed on high basal pressure plateau of SO. The symptomatic group also had a higher serum level of gastrin and a greater BAO than those of other two groups. No difference of serum levels of glucagon and somatostatin was found among these three groups. The hypertonic dyskinesia of SO and hypergastrinemia are possibly important factors in the pathogenesis of postcholecystectomy syndrome.

Mucosal wound and cicatricial stricture formation in the dog trachea: an experimental study

Complete healing of full-thickness tracheal mucosal wounds of different sizes was studied in three groups of dogs. No stricture was observed when the mucosal wounds were less than 20 x 15 mm. Obvious stricture, however, occurred when the wounds were 20 x 25 mm. Normal epithelium regenerated on the wounded areas in all of the three groups within seven weeks.

Cytophotometric DNA analysis on canine stomach carcinogenesis induced by ENNG

DNA content and nuclear area were measured by microspectrophotometry in gastric carcinogenesis of three adult wolfdogs induced by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG). The mean values and standard deviations of DNA content and nuclear area in normal gastric mucosa were 10.03 +/- 2.30 AU and 28.76 +/- 5.85/microns2; those in atrophic gastritis were 12.04 +/- 3.34 AU and 28.69 +/- 8.02/microns2; in mild dysplasia 13.52 +/- 3.73 AU and 28.23 +/- 8.12/microns2; in moderate dysplasia 20.88 +/- 4.57 AU and 47.58 +/- 10.74/microns2; in severe dysplasia 24.01 +/- 4.48 AU and 56.64 +/- 12.53/microns2; in well-differentiated adenocarcinoma 33.07 +/- 9.38 AU and 72.99 +/- 15.57/microns. These figures were different (P less than 0.01). The nuclear area of gastric carcinoma increased with DNA content (r = 0.73, P less than 0.01). The distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy increased in cancer cells. These findings indicate that DNA ploidy patterns and nuclear area can be useful indices for differentiating carcinoma from precancerous lesions.

The efficacy of furazolidone and metronidazole in the treatment of chronic gastritis associated with Helicobacter (Campylobacter) pylori--a randomized double-blind placebo-controlled clinical trial

Seventy-two patients with Helicobacter pylori-associated chronic gastritis were randomized to a 3-week oral treatment with furazolidone 0.1g t.i.d. or metronidazole 0.2g t.i.d. or placebo. Endoscopy was performed before and after treatment, and biopsy specimens were taken from the antrum of the stomach for histological examination and culture of Helicobacter pylori. Disappearance rates of Helicobacter pylori in furazolidone, metronidazole and the control groups were 74% (20/27) if considering completion of therapy, the 20/25 or 80%, 33.3% (8/24) and 14.3% (3/21) respectively. There was a significant difference in the disappearance rate of Helicobacter pylori between furazolidone and metronidazole, and between furazolidone and the placebo group (p less than 0.01), but there was no such difference between metronidazole and the placebo group (p greater than 0.05). In the patients receiving furazolidone, the eradication of Helicobacter pylori was accompanied by marked improvement in both inflammatory infiltration in the gastric mucosa and symptoms. These results reasonably suggest that Helicobacter pylori may play an etiological role in the pathogenesis of chronic gastritis, and that furazolidone is effective in the treatment of Helicobacter pylori-associated chronic gastritis.