[Analysis of the effect and safety of lumen reshaping after endovascular repair of Stanford B type aortic dissection at different intervention times].

Objective: To Compare the effects and safety of lumen reshaping after thoracic endovascular aortic repair (TEVAR) for Stanford B type aortic dissection (AD) at different intervention times. Methods: A retrospective analysis was conducted on the clinical data of 189 patients with Stanford type B aortic dissection treated with TEVAR at the Affiliated Hospital of Chengde Medical College from January 2016 to December 2020.Based on the time from onset to surgery, patients were divided into an early intervention group (≤14 days, n=127) and a delayed intervention group (>14 days, n=62).The diameters of the total aorta, true lumen and false lumen at different times and planes (S1 plane: at the bifurcation of the pulmonary artery; S2 plane: at the lower edge of the left atrium; S3 plane: at the upper edge of the celiac trunk) post-surgery were compared between the two groups, and the rate of change in diameters of true and false lumens across these planes was calculated. The patients were followed until December 1st, 2023, and the median follow-up time was 45(40, 49) months. The postoperative complications and survival of the two groups were compared. Results: The early intervention group comprised 86 men and 41 women, with an average age of (58.3±10.7) years. The delayed intervention group included 41 men and 21 women, with an average age of (58.5±9.2) years. Both groups had an operation success rate of 100%. Six months post-surgery, the early intervention group had an expansion rate of the true lumen diameter at planes S2 and S3 of 40.1%(25.5%, 56.1%) and 5.3%(-2.5%, 15.8%), respectively, which was superior to the delayed intervention group's 18.5%(10.6%, 39.8%) and 1.0%(-8.2%, 9.6%) (both P<0.05).The early intervention group had a reduction rate of the false lumen diameter at planes S1, S2, and S3 of -56.2%(-61.3%, -48.8%), -70.4%(-81.8%, -56.6%), and -5.4%(-17.4%, 0.1%), respectively, better than the delayed intervention group's -44.2%(-53.7%, -38.3%), -49.0%(-57.6%, -35.8%), and -3.1%(-6.7%, 1.8%) (all P<0.05).At plane S1, the true lumen diameter of patients in both groups showed an increasing trend over 36 months post-surgery, while the false lumen diameter showed a decreasing trend (both P<0.05).At plane S2, the true lumen diameter of patients in the early intervention group exhibited an increasing trend over 36 months post-surgery, and the false lumen diameter exhibited a decreasing trend (both P<0.05).At plane S3, the total aortic diameter of patients in the delayed intervention group showed a slight increasing trend over 36 months post-surgery (P<0.05).The overall survival time were 45.0 months (95%CI: 42.9-47.1) for patients in the early intervention group and 46.0 months (95%CI: 43.5-48.5) for those in the delayed intervention group, with no statistically significant difference observed (P>0.05).The incidence rates of complications such as aortic rupture, retrograde Type A dissection, new distal endograft dissection, endoleak, paraplegia, and others showed no statistically significant difference between the two groups (all P>0.05), with no cases of stent migration or deformation observed. Conclusion: Early intervention for Stanford type B aortic dissection provides a better aortic remodeling outcome than delayed intervention, with similar safety.

[Advances in internal treatment of gastroesophageal reflux-related cough].

Gastroesophageal reflux-related cough (GERC) is a clinical syndrome characterized by cough, caused by reflux of gastroduodenal contents into esophagus or oral cavity. The overall treatment effectiveness of GERC is poor because it is difficult to identify patients who are truly responsive to anti-reflux treatment due to the lack of gold standard diagnostic criteria for GERC. Acid-suppressive therapy is the first-line treatment for GERC, and other treatments include lifestyle modification, prokinetics, neuromodulators, upper esophageal sphincter reflux band and endoscopic anti-reflux surgery.

[The value of aspirin challenge tests in the diagnosis of non-steroidal anti-inflammatory drugs-exacerbated respiratory disease].

Objective: To investigate the value of aspirin challenge tests in the diagnosis of non-steroidal anti-inflammatory drugs-exacerbated respiratory disease (NERD). Methods: Fifty patients (22 males and 28 females; aged 16-61 years) who were diagnosed with chronic rhinosinusitis with nasal polyps (CRSwNP) with/without asthma, and underwent NERD standardized diagnosis in the Allergy Centre of West China Hospital, Sichuan University from December 2021 to November 2022 were included in the study. The first step was asking about the history of exacerbation respiratory symptoms after intake of any non-steroidal anti-inflammatory drug, including aspirin; the second step was performing intranasal aspirin challenge (IAC); and the third step was performing oral aspirin challenge (OAC). The diagnosis of NERD was made if any of the above steps was positive, and the subsequent steps were not performed, otherwise the diagnosis was made to OAC. If OAC was negative, the diagnosis was non-NERD. All patients completed the sino-nasal outcome test 22 (SNOT 22) score, Lund-Kennedy score by nasal endoscopic, allergen skin prick test, blood routine and serum total IgE test. SPSS version 20.0 was used for statistical analysis. Results: The diagnosis of NRED was confirmed in 27 patients (27/50, 54%). Seven (7/50, 14%) of them were diagnosed by clinical history and 20 (20/50, 40%) were diagnosed by aspirin challenge tests, of which 17 (17/20, 85%) were positive to IAC and 3 (3/20, 15%) to OAC. Of the 43 patients who underwent IAC testing, only 2 (2/43, 5%) developed asthma attacks during challenge. Comparing the clinical characteristics of patients in NERD and non-NERD group, there were significant differences between the two groups in gender (P=0.001), hyposmia (P=0.003), history of repeated CRSwNP surgeries (P=0.028), comorbid asthma (P=0.013), SNOT-22 score (P=0.004) and the percentage of peripheral blood eosinophil (P=0.043). Conclusions: Patients may be underdiagnosed if the diagnosis of NERD is made only by medical history, and it is necessary to carry out aspirin challenge tests. IAC is an important means to diagnose NERD with high accuracy and good safety. However, If IAC is negative, further OAC is required.

[Idiopathic pleuroparenehymal fibroelastosis: five case reports and review of literature].

Objective: To raise the awareness of idiopathic pleuroparenehymal fibroelastosis (iPPFE) through investigating the clinical, radiographic and pathological features. Methods: Five cases of iPPFE proved by pathology. The clinical data were studied respectively, and the relevant literature was reviewed. Results: All the cases of iPPFE were manifested by cough and dyspnea. The patients including 3 males and 2 females, aged from 30 to 70 years Chest CT scan showed pleural thickening, subpleural consolidation in both upper lungs complicated with tractive bronchiectasis.Computed tomography-guided percutaneous lung biopsy or surgical lung were performed and the same pathological showed pleura and subpleural dense elastic and collagen fibers. The elastic fibers stain was also positive,which was consistent with PPFE. One patient received low-dose corticosteroid, two received pirfenidone therapy, the others received no treatment. Three patients were stable during the follow-up. Conclusions: iPPFE has characteristic pathological features. However, the number of clinically reported cases is low due to missed diagnosis or misdiagnosed. Improving the understanding of features of iPPFE is helpful for the dianosis, therapy, and prognosis of this disease.

[Analysis on results of occupational health examination in 677 workers exposed to inorganic fluorine].

Objective: To analyze the health hazards of fluorine and its inorganic compounds to workers exposed to fluorine, and to provide technical support for the protection of workers exposed to fluorine and the revision of occupational disease diagnostic standards. Methods: In January 2019, 677 workers exposed to fluorine in a fluorine chemical company in Hunan Province were selected by cluster sampling, and occupational health examination was conducted. The suspected occupational poisoning workers were diagnosed as occupational diseases, which were divided into poisoning group and non-poisoning group. T test and Pearson χ(2) test were used for statistical analysis. Results: A total of 73 occupational chronic fluorosis patients were diagnosed. 93.15% (68/73) of the skeletal lesions were multiple, and the most frequent sites were the upper tibia and fibula. 35.00% (21/60) , 50.00% (18/36) and 58.82% (10/17) of the tibia, fibula, ulna and radius had periosteal changes only on one side. Other abnormal results were mainly dental calculus (60.71%, 411/677) , fatty liver (48.89%, 331/677) , abnormal electrocardiogram (44.17%, 299/677) , decreased bone mass (33.53%, 227/677) and increased ALT (13.15%, 89/677) . Compared with non-poisoning group, the age, length of service exposed to fluoride and fatty liver detection rate of poisoning group were higher, and the differences were statistically significant (P<0.01) . Conclusion: The changes of long bone caused by inorganic fluoride only occur in one side, so the basic location of occupational health examination should include bilateral long bone to avoid missed diagnosis. It is difficult to diagnose occupational poisoning with single slight periosteal ossification, it is suggested that the standard should be revised to specify the degree.

[Analysis of the incidence of pneumoconiosis in Hunan province].

Objective: To analyze the epidemiological characteristics of pneumoconiosis in Hunan Province. Methods: In November 2018, we collected the type of work, pneumoconiosis type, pneumoconiosis stage, length of service, age of onset and complications of pneumoconiosis cases diagnosed by Hunan occupational disease prevention and control hospital from January 2017 to October 2018. A total of 3 325 cases of pneumoconiosis were collected, including 651 cases (19.58%) of occupational pneumoconiosis and 2674 cases (80.42%) of clinically diagnosed pneumoconiosis. The measurement data were expressed by x±s. The comparison between groups was performed by independent sample t test and one-way ANOVA. Results: The age of 651 patients with occupational pneumoconiosis was 35.59-85.15 years old, the average age of onset was (54.27±8.29) years, and the average exposure to dust was (14.74±8.60) years. 2 674 cases of clinically diagnosed pneumoconiosis were 26.85~87.02 years old. The average age of onset was (55.26±7.38) years, and the average exposure time was (18.83±9.35) years. Compared with silicosis patients, coal workers' pneumoconiosis patients had longer exposure time, the difference was statistically significant (P<0.05) , and the difference was statistically significant (F=3.678, P<0.05) . There were no complications in 651 cases of occupational pneumoconiosis. Among 2 674 cases of clinically diagnosed pneumoconiosis, 710 cases (26.55%) had complications. Conclusion: Further attention should be paid to the clinical diagnosis of pneumoconiosis in Hunan Province.

[An analysis of status of personnel in occupational disease prevention and treatment institutions in Hunan Province, China, from 1996 to 2015].

Objective: To analyze the status of personnel in occupational disease prevention and treatment institutions in Hunan Province, China, from 1996 to 2015, to predict staff composition using grey model (GM) (1, 1) , and to provide a scientific basis and reference for optimizing human resource planning of occupational disease prevention and treatment in other provinces and regions and promoting the service capacity of the institutions. Methods: The data of the staff in occupational disease prevention and treatment institutions in Hunan Province, China, from 1996 to 2015 were obtained from the established basic information management system. The descriptive analysis method was used to analyze the dynamic changes in number and composition of the staff and the GM (1, 1) was used to predict the staff composition. Results: The numbers of the staff members in 1996 and 2015 in occupational disease prevention and treatment institutions in Hunan Province, China were 1591 and 1429, respectively. In the twenty years, the main education level of the staff transformed from "technical secondary school education and non-academic qualifications" to "bachelor degree or above and college degree"; the main major of the staff transformed from "other majors" to "public health and clinical medicine"; the proportion of the staff members without professional titles changed from >1/3 to 5%; and the proportions of the staff members with senior, intermediate, and junior professional titles were steadily rising. GM prediction showed that the proportions of highly educated staff members in 2018 and 2020 would be up to 41.00% and 45.61%, respectively; and the proportions of the staff members with a major in public health in 2018 and 2020 would be up to 44.15% and 46.60%, respectively. Conclusion: The staff in occupational disease prevention and treatment institutions in Hunan Province, China, in the twenty years have slight changes in staff size and great improvement in staff quality, which is beneficial to sustainable development of the occupational disease prevention and treatment undertakings. The education level and major will be further optimized in the next five years.

[Unilateral pleural effusion as first manifestation in Takayasu arteritis: a case report and review of literature].

Objective: To highlight the characteristics of pulmonary arterial involvement in Takayasu arteritis. Methods: The clinical and radiological data of a patient with Takayasu arteritis presenting with unilateral pleural effusion were studied and relevant literature was reviewed. The key words, "Takayasu arteritis" and "pleural effusion" were analyzed through literature retrieval in databases. Results: This 58 year-old female patient presented with shortness of breath. The chest CT scan showed bilateral hilar enlargement and pleural effusion on the left side. The blood pressure was not measurable in the course of the disease. After the aorticopulmonary-arteriography, we found that the pulmonary artery and the subclavian artery were involved. The diagnosis of Takayasu arteritis was made, and glucocorticoid therapy was initiated, with significant clinical and radiological improvement after therapy. Literature review found 4 cases of Takayasu arteritis with unilateral pleura effusion, ranging from 32 to 35 years of age, with a female predominance(Female∶Male=3∶1). The chief complaints were fever, chest pain and hemoptysis. All the patients recovered after the treatment of glucocorticoids. Conclusions: Takayasu arteritis presenting with unilateral pleural effusion was easily misdiagnosed as primary pulmonary diseases. Careful physical examination and timely angiography can be used to make the diagnosis.

[An investigation of prevalence of occupational diseases and treatment implementation in migrant workers in Hunan, China].

Objective: To investigate the prevalence of occupational diseases and treatment implementation in migrant workers in Hunan, China, and to provide a scientific basis for related departments to develop preventive and treatment measures and social security system for migrant workers. Methods: A retrospective investigation was performed in 2015 to collect the information of occupational diseases in migrant workers, and age, type of work, type of occupational disease, and implementation of employment injury insurance for occupation diseases were analyzed. Results: The migrant workers with occupational diseases accounted for 50.43% (11 280/22 368) of all patients with occupational diseases in Hunan, among whom 99.4% (11 212/11 280) were male workers. The mean age of migrant workers with occupational diseases was 55 years. The types of occupational diseases involved 6 categories such as occupational pneumoconiosis and occupational skin diseases, totaling 42 legal occupational diseases; 98.31% of all migrant workers (11 089/11 280) had occupational pneumoconiosis. The main types of work were underground coal miners (62.42%) , heading drivers (29.79%) , and haulage workers (2.20%) in coal mines and non-coal mines. A total of 27.25% migrant workers with occupational diseases (2 072/7 605) enjoyed employment injury insurance, and 20.84% (1 585/7 605) did not receive any medical or life compensations. Conclusion: The occupational diseases in migrant workers in Hunan are mainly pneumoconiosis, and a large proportion of those with occupational diseases do not enjoy implementation of treatment. Coal mines and non-coal mines are the high-risk areas for occupational diseases in migrant workers and should be the focus of prevention and control.

Predominance of Cryptococcus neoformans var. grubii multilocus sequence type 5 and emergence of isolates with non-wild-type minimum inhibitory concentrations to fluconazole: a multi-centre study in China.

There are few data on the molecular epidemiology of cryptococcosis in China. Here we investigated the species distribution, molecular types and antifungal susceptibilities of 312 Cryptococcus neoformans species complex isolates from ten hospitals over 5 years. Isolates were identified by internal transcribed spacer (ITS) sequencing and by two matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems. Multilocus sequence typing (MLST) was used to verify species/variety and to designate molecular types. Susceptibility to six antifungal drugs was determined by the Sensititre YeastOne™ method. Cryptococcus neoformans was the predominant species (305/312 isolates (97.8%), all were ITS type 1, serotype A), of which 89.2% (272/305) were C. neoformans var. grubii MLST sequence type (ST) 5 and 6.2% (19/305) were ST31. Other C. neoformans var. grubii STs were rare but included six novel STs. Only two strains were C. neoformans var. neoformans (both serotype AD). Cryptococcus gattii was uncommon (n = 7, four ITS types) and comprised five MLST STs including one novel ST. For C. neoformans var. grubii, the proportion of isolates with non-wild-type MICs to fluconazole significantly rose in the fourth study year (from 0% (0/56 isolates) in the first year to 23.9% (17/71) in the fourth year), including five isolates with fluconazole MICs of ≥32 mg/L. The study has provided useful data on the species epidemiology and their genetic diversity and antifungal susceptibility. The proportional increase in isolates with non-wild-type MICs to fluconazole is noted.

Effect of neural stem cell transplantation combined with erythropoietin injection on axon regeneration in adult rats with transected spinal cord injury.

We investigated the effect of neural stem cells (NSC) and erythropoietin (EPO) on axon regeneration in adult rats with transected spinal cord injury, and provided an experimental basis for clinical treatment. Forty Wistar rats with T10-transected spinal cord injury were randomly divided into four groups of ten rats: a control group (group A), an NSC-transplant group (group B), an NSC-transplant and EPO group (group C), and an EPO group (group D). Biotinylated dextran amines (BDA) anterograde corticospinal cord neuronal tracing and Fluoro-Gold (FG) retrograde tracing were carried out at the 8th week after operation to observe the regeneration of nerve fibers. The Basso, Beattie, and Bresnahan (BBB) locomotor score was used to evaluate restoration. 1) BDA and FG immunofluorescence staining: in group C, a large number of regenerated axons were observed and some penetrated the injured area. In group B, only a small number of regenerated axons were observed and none penetrated the injured area. In group D, only sporadic regenerated nerve fibers were observed occasionally, while in group A, no axonal regeneration was observed. In group C, a small number of cones and axons emitted yellow fluorescence, and no FG-labeled cells were observed in the other groups. 2) The BBB scores for group C were higher than those for the other groups, and the differences were statistically significance (P < 0.05). NSC transplantation combined with EPO intraperitoneal injection may benefit axon regeneration in rats with transected spinal cord injury, and accelerate the functional recovery of the hindlimb locomotor.

Glucocorticoid induced autophagy in N1511 chondrocyte cells.

OBJECTIVE: To determine whether autophagy was involved in chondrocyte cells post Glucocorticoids (GCs) treatment. MATERIALS AND METHODS: LC3-GFP reporter plasmid transfection and western blotting analysis were conducted to determine the autophagic vesicles and autophagy-associated molecules in the N1511 chondrocyte cells post dexamethasone (Dex) treatment. And the N1511 cell viability was also determined by MTT assay. RESULTS: We found that autophagy was induced in the N1511 chondrocyte cells post treatment with Dex of 5 µM to 1 mM, and the autophagy-induction by Dex could be inhibited by 3 MA and RU486, a GC antagonist. And the autophagy induced by the high dose of Dex (200 µM or 1 mM) was associated with a reduction of N1511 cell viability. CONCLUSIONS: These results suggested that GCs could induce autophagy, as might contribute to the viability reduction of chondrocyte cells.

An overlapping protein-coding region in influenza A virus segment 3 modulates the host response.

Influenza A virus (IAV) infection leads to variable and imperfectly understood pathogenicity. We report that segment 3 of the virus contains a second open reading frame ("X-ORF"), accessed via ribosomal frameshifting. The frameshift product, termed PA-X, comprises the endonuclease domain of the viral PA protein with a C-terminal domain encoded by the X-ORF and functions to repress cellular gene expression. PA-X also modulates IAV virulence in a mouse infection model, acting to decrease pathogenicity. Loss of PA-X expression leads to changes in the kinetics of the global host response, which notably includes increases in inflammatory, apoptotic, and T lymphocyte-signaling pathways. Thus, we have identified a previously unknown IAV protein that modulates the host response to infection, a finding with important implications for understanding IAV pathogenesis.

Gastroesophageal and laryngopharyngeal reflux profiles in patients with obstructive sleep apnea/hypopnea syndrome as determined by combined multichannel intraluminal impedance-pH monitoring.

BACKGROUND: The profiles of gastroesophageal reflux (GER) and laryngopharyngeal reflux (LPR) in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) have never been explored. The aim of the study was to investigate the reflux profile in OSAHS patients. METHODS: Consecutive snoring out-patients suspected with having OSAHS and 20 healthy volunteers were included. All subjects underwent simultaneous 24-h combined multichannel intraluminal impedance-pH (MII-pH) monitoring and polysomnography. Obstructive sleep apnea/hypopnea syndrome was defined when the apnea/hypopnea index was over 5. Stepwise multiple logistic regression analysis was performed to determine the predictor for OSAHS. KEY RESULTS: Fifty-three patients were included, 37 with and 16 without OSAHS. The prevalence of reflux symptoms was similar between OSAHS (35.1%) and non-OSHAS (37.5%) patients. More OSAHS patients, compared with non-OSAHS patients and healthy volunteers, had pathologic acid GER, nocturnal acid GER, and prolonged acid clearance (P < 0.001). However, no difference in non-acid reflux episodes was observed among the three groups. Laryngopharyngeal reflux was detected in 51.4%, 43.8%, and 35.0% of OSAHS, non-OSAHS, and healthy volunteers, respectively (P = 0.034). In OSAHS patients, there was no difference in the sleep parameters between patients with and without LPR. Body mass index was the only predictor of OSAHS in the regression analysis. CONCLUSIONS & INFERENCES: OSAHS patients have more pathologic acid GER and prolonged acid clearance than non-OSAHS patients whereas non-acid reflux was similar between the two groups. However, BMI, not GER, is the only independent predictor for OSAHS. Laryngopharyngeal reflux occurs in more than half of OSAHS patients despite no significant association with OSAHS.

Predictors of acid suppression success in patients with chronic laryngitis.

BACKGROUND: Up to 50% of the patients suspected of reflux laryngitis syndrome failed to respond to acid suppression therapy. However, predictors of acid suppression success have not been determined. METHODS: Consecutive patients with chronic laryngitis were enrolled prospectively. All the patients underwent laryngoscopy, esophagogastroduodenoscopy and 24-h multichannel intraluminal impedance and pH (MII-pH) monitoring before receiving rabeprazole 10 mg b.i.d. for 3 months. Patient was considered as a responder to acid suppression if the chief laryngeal complaint score during the last week since last interview had decreased by at least 50% after the start of therapy compared with baseline. Cox regression analysis was used to determine the independent predictors of acid suppression success. KEY RESULTS: Of 92 patients (age 42.4 ± 14.3 years, 50 women), 42 (45.7%) responded to acid suppression after 3 months. Gastroesophageal reflux disease was defined in 22 patients, of whom 19 patients had pathological distal esophageal acid exposure and 5 were defined as erosive esophagitis. The time to response showed a significant hazard ratio for patients with increased distal esophageal acid exposure time (ß: 0.93; HR: 2.55; 95% CI: 1.24-5.24; P = 0.011) and increased laryngopharyngeal bolus exposure time (BET; ß: 0.96; HR: 2.61; 95% CI: 1.36-5.00; P = 0.004). The latter had the best Youden Index (0.34) and accuracy (68.5%). CONCLUSIONS & INFERENCES: The success of acid suppression on chronic laryngitis could be predicted using reflux parameters detected by MII-pH, among which increased laryngopharyngeal BET is the best.

Prevalence of erosive esophagitis and Barrett's esophagus in the adult Chinese population.

BACKGROUND AND STUDY AIM: The aim of this study was to determine the prevalence, characteristics, and risk factors of erosive esophagitis and Barrett's esophagus in an adult Chinese population without gastroesophageal reflux symptoms. PATIENTS AND METHODS: Between March 2006 and February 2007, consecutive individuals aged between 18 and 75 years, who underwent routine upper endoscopy as part of their regular medical examination were recruited. Demographic and medical information were collected. Erosive esophagitis was defined endoscopically as visible breaks of the distal esophageal mucosa. Barrett's esophagus was diagnosed endoscopically and confirmed histologically. "Silent GERD" was defined when erosive esophagitis and/or Barrett's esophagus were present in an individual without reflux symptoms. RESULTS: Among the 2580 individuals included, erosive esophagitis and Barrett's esophagus were found in 4.3 % (n = 110) and 1.0 % (n = 27), respectively. In individuals with erosive esophagitis and Barrett's esophagus, 33.6 % and 40.7 %, respectively, were asymptomatic. Thus, the prevalence of erosive esophagitis and Barrett's esophagus in individuals without GERS was 1.6 % and 0.5 %, respectively, giving an overall prevalence of silent GERD of 2.0 % (46 / 2270). Multivariate analysis identified that male sex (odds ratio [OR] = 2.87, 95 % confidence interval [CI] 1.24 - 6.66; P = 0.014), hiatus hernia (OR = 9.68, 95 %CI 5.00 - 17.95; P < 0.001), and alcohol consumption (OR = 3.17, 95 %CI 1.44 - 6.97; P = 0.004) were positively associated with erosive esophagitis, whereas Helicobacter Pylori infection (OR = 0.37, 95 %CI 0.14 - 0.98; P = 0.046) was negatively associated with erosive esophagitis. Alcohol consumption (OR = 5.32, 95 %CI 1.55 - 13.33; P = 0.008) was positively associated with Barrett's esophagus in asymptomatic individuals. CONCLUSION: In this cohort of the adult Chinese population without reflux symptoms, the prevalence of erosive esophagitis and Barrett's esophagus is 1.6 % and 0.5 %, respectively, with an overall prevalence of silent GERD of 2.0 %. Male sex, hiatus hernia, and alcohol consumption are positively associated with erosive esophagitis, whereas a negative association exists for H. pylori infection. Alcohol consumption is positively associated with Barrett's esophagus.

Chemical constituents of Selinum cryptotaenium.

A new pyranocoumarin, named secryptotaenin A, determined as 3'(S)-angeloyloxy-3',4'-dihydroseselin, was isolated from the roots of Selinum cryptotaenium, along with thirteen known compounds, umbelliferone, osthol, coumurrayin, (+)-heraclenol, longshengensin A, anomalin, ferulic acid, galactitol, stearic acid, melissic acid, lignoceric acid, beta-sitosterol and daucosterol. Their structures were determined on the basis of spectroscopic methods.

Ac transposition is impaired by a small terminal deletion.

In maize, the P1-vv allele specifies variegated pericarp and cob pigmentation, and contains an Ac transposable element inserted in the second intron of the P1-rr gene. Starting from P1-vv, we recovered a new allele, called P1-vv5145, which gives an extremely light variegated pericarp and cob phenotype. The P1-vv5145 allele contains an Ac element ( Ac5145) at the same position and in the same orientation as in the progenitor P1-vv allele; however, the P1-vv5145 allele has a 2-bp deletion which removes the last nucleotide (A) from the 3' end of the Ac element, and an adjacent flanking nucleotide (C) from the p1 intron. In crosses with a Ds tester stock, P1-vv5145 shows a normal ability to induce Ds transposition; however, Ac excision from P1-vv5145 is 3800-fold less frequent than from the progenitor P1-vv allele. Our results demonstrate that the alteration of the 3' terminal base strongly impairs Ac transposition. The P1-vv5145 allele thus provides a relatively stable source of Ac transposase for controlling Ds transposition in genetic experiments. In addition, we describe two further alleles ( P1-ww7B8, P1-ww9A146-3) that contain deletions of Ac and flanking p1 gene sequences. These latter deletions are larger and involve the 5' end of the the Ac element. A model is proposed to explain the formation of one-sided deletions as a consequence of Ac transposition during replication of the element.

Ac insertion site affects the frequency of transposon-induced homologous recombination at the maize p1 locus.

The maize p1 gene regulates the production of a red pigment in the kernel pericarp, cob, and other maize floral tissues. Insertions of the transposable element Ac can induce recombination between two highly homologous 5.2-kb direct repeat sequences that flank the p1 gene-coding region. Here, we tested the effects of the Ac insertion site and orientation on the induction of recombination at the p1 locus. A collection of unique p1 gene alleles was used, which carry Ac insertions at different sites in and near the p1 locus, outside of the direct repeats, within the direct repeat sequences, and between the direct repeats, in both orientations. Recombination was scored by the numbers of colorless pericarp sectors (somatic frequency) and heritable mutations (germinal frequency). In both the somatic and germinal tests, the frequency of homologous recombination is significantly higher when Ac is inserted between the direct repeats than when Ac is inserted either within or outside the repeats. In contrast, Ac orientation had no significant effect on recombination frequency. We discuss these results in terms of the possible mechanisms of transposon-induced recombination.