Plastic properties affect the composition of prokaryotic and eukaryotic communities and further regulate the ARGs in their surface biofilms.

Plastic wastes are ubiquitous in the offshore and oceans with an increasing quantity, and inevitably, microbial communities colonized the plastics to form biofilms, which have become dispersal vectors for antibiotic resistance genes (ARGs). This study focused on the impact of plastic properties including hardness, wettability, and zeta-potential on the biomass, prokaryotic and eukaryotic communities and ARGs in biofilms formed on specific plastics (polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET)) in an estuarine environment. The results showed that, in comparison to PP, more biomass characterized by more dry weight, chlorophyll a (Chl a) and total organic carbon (TOC) was found in biofilms formed on PE and PET, which may be related to their lower surface wettability. Proteobacteria were the dominant prokaryotic phyla, and they accounted for 53.06%, 81.90%, 37.06%, 76.25%, and 54.27% of the total sequences in biofilms on PE, PP, PET, water and sediment, respectively. Ascomycota were the predominant eukaryotic phyla in biofilms, water, and sediment, and their abundances were elevated in biofilms on PP, which accounted for 34.73%. The biofilms on PP had a higher relative abundance of ARGs (3.13) compared to those on PE (2.59) and PET (0.23). Furthermore, both the plastic-biofilm properties (e.g. dry weight, Chl a, and TOC) and microbial communities (e.g., Fungi and Proteobacteria) may be involved in regulating the abundance of ARGs. Moreover, mobile genetic elements (MGEs) were significantly correlated to both the absolute and relative abundance of ARGs, indicating that MGEs may regulate the migration of ARGs in biofilms. Taken together, this investigation provides the significance of the plastic type, surface properties, and surrounding environments in shaping microbial communities and ARGs in biofilms formed on plastics.

Spontaneous Abdominal Bleeding from an Infundibulopelvic Ligament Tear in a Patient with Large Ovarian Fibroma.

Ovarian fibromas are rare benign solid tumors of the ovary which are often difficult to differentiate from uterine leiomyomas preoperatively. The symptoms usually include abdominal discomfort and may have ascites and/or an elevation in CA-125 levels. There have been no publications of associated abdominal bleeding to date. The treatment is surgical removal via a laparoscopic or laparotomic approach. We present a case of a 19 cm unilateral ovarian fibroma with abdominal bleeding from a spontaneous right infundibulopelvic ligament (IPL) tear who underwent a laparoscopic and mini-laparotomic right salpingo-oophorectomy. Patients with large ovarian fibromas should be cautioned that abdominal bleeding and/or acute abdominal pain can occur and that a minimally invasive surgical approach is feasible.

Action mechanism of corticosteroids to aggravate Guillain-Barré syndrome.

Corticosteroids have been proved to be ineffective for Guillain-Barré syndrome, but the mechanism remains unknown. In a rabbit model of axonal Guillain-Barré syndrome, treatment with corticosteroids significantly reduced macrophage infiltration in the spinal ventral roots and the survival rate as well as clinical improvement. On 30(th) day after onset, there was significantly higher frequency of axonal degeneration in the corticosteroids-treated rabbits than saline-treated rabbits. Corticosteroids may reduce the scavengers that play a crucial role for nerve regeneration, thus delay the recovery of this disease.

[Types and risk factors of arrhythmia on young patients with acute coronary syndrome in Henan province].

OBJECTIVE: The types and risk factors of arrhythmia were analyzed on acute coronary syndrome (ACS) patients under the age of 44 years who were hospitalized in Henan province between September 2009 to June 2012. METHODS: Medical records of eligible patients were obtained from the information system of the First Affiliated Hospital of Zhengzhou University teleconsultation information center. Middle aged and elderly ACS patients who were hospitalized at the same period served as controls. Data on arrhythmia types, blood pressure, thyroid disease, respiratory sleep apnea syndrome, smoking history, history of alcohol consumption, eating habits, family history of early-onset arrhythmia, laboratory tests were analyzed. RESULTS: (1) Arrhythmia was detected in 110 out of young ACS patients (55%), which was significantly lower than that in the elderly ACS patients (71.05%, P < 0.01). (2) The top three arrhythmias in young ACS patients were: sinus tachycardia (30.50%), the premature ventricular contractions (19.00%), atrial flutter/atrial fibrillation (16.50%). Incidence of sinus tachycardia, atrial flutter/atrial fibrillation were significantly higher while incidence of ventricular tachycardia, ventricular fibrillation, paroxysmal supraventricular tachycardia were significantly lower in young ACS patients than in middle-aged ACS patients (all P < 0.05). The incidence of sinus tachycardia was higher while incidence of ventricular premature accelerated ventricular spontaneous cardiac rhythm, ventricular tachycardia, ventricular fibrillation, non-paroxysmal supraventricular tachycardia, atrial flutter/atrial fibrillation, paroxysmal supraventricular tachycardia, sinus bradycardia, nodal escape, atrioventricular block were significantly lower in young ACS patients than in elderly ACS patients (all P < 0.05). (3) Body mass index, incidence of smoking, coronary three-vessel disease, drinking, eating salty foods, thyroid dysfunction, sleep apnea were significantly higher in youth ACS patients with arrhythmia than in young ACS patients without arrhythmia (all P < 0. 05). (4) Logistic regression analysis found that number of diseased coronary vessels (OR = 24.293), smoking (OR = 1.112) and alcohol consumption (OR = 1.039) were independent risk factor for developing arrhythmia in young ACS patients from Henan province. CONCLUSIONS: The main types of arrhythmia are sinus tachycardia, premature ventricular contractions, atrial flutter/atrial fibrillation and the major risk factors related to the arrhythmia are number of diseased coronary vessels, smoking and alcohol consumption in young ACS patients from Henan province.

[Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

OBJECTIVE: To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. METHODS: Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. RESULTS: (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P < 0.01). (3) Heart rate and diastolic blood pressure were significantly higher in passive smoking group than in control group (all P < 0.05) while systolic blood pressure was similar between the 2 groups (P > 0.05). CONCLUSIONS: Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.

[Effect of the smoking cessation services in the out-patient department for patients with coronary heart disease].

OBJECTIVE: To evaluate the effects and clinical prognosis of out-patient department-based smoking cessation services for coronary heart disease (CHD) patients. METHODS: A total of 140 smoking patients diagnosed with coronary heart disease in our cardiovascular department were randomly divided into the intensive smoking cessation clinic follow-up group (intervention group, patients were informed on the importance and methods to quit smoking at the first visit and reminded for that at months interval for 6 months, n = 70) and the conventional treatment group (control group, n = 70). After 6 months, the smoking status, cardiovascular event rates, drug usage, out-patient medical costs and quality of life were compared between the two groups. RESULTS: Age, gender, concomitant diseases, drug usage were similar between the two groups at baseline (all P > 0.05). After 6 months, smoking quit rate [34.2% (24/70) vs. 5.7% (4/70), P < 0.01], drug use rates: lipid-lowering drugs [95.3% (67/70) vs. 80.4% (56/70)], ß blockers [82.4% (57/70) vs. 41.3% (28/70)], and ACEI/ARB [61.4% (43/70) vs. 34.4% (24/70)] were significantly higher in the intervention group than in the control group, while total cardiovascular event rates [21.4% (15/70) vs. 47.1% (33/70), P < 0.01] and out-patient medical costs (3789.3 RMB vs. 4984.2 RMB, P < 0.01) were significantly lower in the intervention group than in the control group. The quality of life scores derived from MYO health survey questionnaire was significantly higher in the intervention group than in the control group (P < 0.01). The top three reasons responsible for continuous smoking for all patients failed to quit smoking were: (1) others smoked more than me and still alive and healthy [90.3% (56/62)]; (2) smoking helped me to keep relaxed and reduce trouble in daily work and life [70.9% (44/62)]; (3) smoking was essential while chatting and drinking with friends [66.1% (41/62)]. The overall satisfactory rate to this smoking cessation program was 42.8% and the satisfactory rate was up to 50.0% by patients. CONCLUSIONS: Intensive outpatient smoking cessation follow-up program can significantly improve the smoking cessation rates, the guideline drug use rate and the quality of life while reduce medical costs for coronary heart disease patients.

[Effects of long-term fertilization on organic carbon functional groups in black soil as revealed by synchrotron radiation soft X-ray near-edge absorption spectroscopy].

A 20 years (1984-2004) stationary field experiment was conducted to evaluate the effects of long-term application of chemical fertilizers (N or NPK) alone or in combination with low (0.125 kg x hm(-2)) or high dose of corn stalk (0.25 kg x hm(-2)) on organic carbon functional groups in black soil using synchrotron radiation soft X-ray near-edge absorption spectroscopy (C-1s NEXAFS). Compared with the control (CK) treatment, the aromatic C and the carboxyl C of soil increased, whereas the aliphatic C, the carbonyl C and the aliphatic C/aromatic C ratio decreased after the application of chemical fertilizer alone. After the application of chemical fertilizations in combined with corn stalk, the aromatic C decreased while the aliphatic C and the aliphatic C/aromatic C ratio increased as compared to N or NPK fertilizer treatment. And the change tendency was more obvious with the increase in the dose of corn stalk applied. Regardless of corn stalk application, the aromatic C, the aliphatic C, and the aliphatic C/aromatic C ratio were all higher for NPK than for N fertilizer treatment. The above results indicated that, compared with the no-fertilizer control treatment, the application of chemical fertilizers alone resulted in the relative proportion of aromatic compounds increased whereas that of aliphatic hydrocarbon compounds decreased. On the other hand, the relative proportion of the aliphatic hydrocarbon compounds was higher after the application of chemical fertilizers with than without corn stalk, with high than with low dose of corn stalk, and with NPK than with N fertilization. C-1s NEXAFS spectroscopy could characterize in situ the changes of organic carbon functional groups in soil under long-term stationary fertilization.

[Relationship between polymorphism of interleukin-8 and silicosis susceptibility].

OBJECTIVE: To explore the relationship between the polymorphisms of interleukin-8 (IL-8) and the silicosis susceptibility. METHODS: The case group consisted of 101 male patients with stage I silicosis diagnosed by the Pneumoconiosis Diagnosis Expert Panel according to the Chinese National Diagnosis Criteria of Pneumoconiosis (GBZ 70-2009). The control group consisted of 121 workers without silicosis exposed to same dusts. The cases and the controls had the same dust exposure history. The peripheral venous blood was drawn from each subject. DNA was extracted from leucocytes by the salting method. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) techniques and PCR were used to examine polymorphism of IL-8 (Met31Arg, 781C/T, -251A/T and RA+860). RESULTS: There were no the differences of age, cumulative exposure time and smoking between the cases and the controls (P > 0.05). The frequencies of IL-8 (Met31Arg) GT genotypes in cases and controls were 12.87% and 2.48%, respectively, there was significant difference (P < 0.05). The frequencies of allele G in cases and controls were 6.44% and 2.07%, respectively, there was significant difference (P < 0.05). The frequencies of IL-8 (-251A/T) AA genotypes in cases and controls were 9.90% and 25.64%, respectively, there was significant difference (P < 0.05). The frequencies of IL-8 (781C/T) CC, CT, TT genotypes in cases and controls were 38.61%, 40.59%, 20.79% and 46.28%, 40.50%, 13.22%, respectively, there was no significant difference (P > 0.05). The frequencies of IL-8 (RA+860) GG, GC and CC genotypes in cases and controls were 75.25%, 21.78%, 2.97%, 80.17%, 14.88%, 4.96%, respectively, there was no significant difference (P > 0.05). CONCLUSIONS: IL-8 (Met31Arg and -251A/T) genetic polymorphisms might play a role in the development of silicosis. The risk of pneumoconiosis in workers carrying (Met31Arg) genotype GT is likely to increase. The risk of pneumoconiosis in workers carrying IL-8 (-251A/T) AA genotype is likely to decrease. The relationship between IL-8 781C/T and RA+860 genes polymorphisms and silicosis is not found.

[Clinical study of terminating biochemical pregnancy and early clinical pregnancy with mifepristone and misoprostol].

OBJECTIVE: To explore the efficacy and safety of terminating biochemical pregnancy (the stage in which intrauterine or ectopic pregnancy cannot be confirmed) with mifepristone and misoprostol. METHODS: Mifepristone (150 mg) combined with misoprostol (600 microg) 3 days later were given to 500 biochemical pregnancies (G(1)), 500 early clinical pregnancies (G(2)) and 500 clinical pregnancies (G(3)) which were classified according to amenorrhea days, serum human chorionic gonadotropin-beta subunit (beta-hCG) and vaginal B-ultrasonic examinations. All were observed for 6 hours after taking misoprostol and returned for assessment per week. RESULTS: Expulsion of conceptus was G(1) 123 (24.6%, 123/500), G(2) 438 (87.6%, 438/500) and G(3) 467 (93.4%, 467/500). Failure rate was G(1) 6 (1.2%, 6/500), G(2) 24 (4.8%, 24/500) and G(3) 79 (15.8%, 79/500) for ongoing pregnancies, hospitalizations for suspected ectopic pregnancies and surgical intervention for heavy or long-time bleeding. Bleeding cases during the administration of mifepristone were G(1) 272 (54.4%, 272/500), G(2) 141 (28.2%, 141/500) and G(3) 87 (17.4%, 87/500); the mean bleeding days were G(1) (5.8 +/- 1.5), G(2) (9.0 +/- 2.9) and G(3) (14.3 +/- 5.9) days. Other side effects including abdominal pain, nausea, vomiting and diarrhea were low and light in each group, increasing with advancing gestational age. Menses recovery was 486 (97.2%, 486/500), 452 (90.4%, 452/500) and 433 (86.6%, 433/500) for each group on scheduled time. Satisfaction was 499 (99.8%, 499/500), 485 (97.0%, 485/500) and 369 (73.8%, 369/500) respectively. CONCLUSION: Mifepristone and misoprostol in combination is as safe, and effective for termination of biochemical pregnancies as ordinary medical abortion. It does not need to wait till ectopic pregnancy is excluded.

[The mechanistic rote of KCNH2 gene L413P and L559H mutations in long QT syndrome].

OBJECTIVE: To investigate the molecular pathogenesis for two novel mutations L413P and L559H of KCNH2 found in Chinese patients with long QT syndrome. METHODS: L413P and L559H mutant constructs were generated by site-directed mutagenesis using human wild-type (WT) pcDNA3-HERG cDNA as a template. WT and mutant constructs were transiently transfected into human embryonic kidney 293 cells using lipofectamine method. After transfection, the recording of HERG current was performed using patch clamp technique. The expression and cellular localization of HERG protein were studied with Western blot and immunofluorescence methods. RESULTS: Electrophysiological recordings showed that L413P and L559H mutations did not express HERG current. Western blot analysis revealed that only 135 000 immature HERG protein was expressed in L413P and L559H-transfected cells, whereas both mature and immature forms of HERG protein were observed in WT-transfected cells. Immunofluorescence study showed that L413P and L559H mutant proteins were predominantly localized around the nucleus, suggesting that the mutant channels are retained in the endoplasmic reticulum. When L413P or L559H was co-transfected with equal amount of WT plasmids, both 135 000 and 155 000 forms of HERG protein were observed, and the HERG current was not significantly changed as compared with that of WT transfection alone. Low temperature and E-4031could not rescue these two mutant channels. CONCLUSIONS: The L413P and L559H mutations resulted in protein trafficking defects with failure of mutant proteins to reach the plasma membrane. However, both biochemical and electrophysiological results showed that the mutations did not have a dominant-negative effect on WT, indicating that the mechanism of the L413P and L559H mutations might be haploinsufficiency.

[Relationship between genetic polymorphism of interleukin-6 and pneumoconiosis].

OBJECTIVE: To explore the relationship between interleukin-6 (IL-6) (-634C/G) genetic polymorphisms and the pneumoconiosis. METHODS: A total of 104 male stage I pneumoconiosis patients diagnosed by the Pneumoconiosis Diagnosis Expert Panel according to the Chinese National Diagnosis Criteria of Pneumoconiosis (GBZ 70 - 2002) were selected. The pneumoconiosis comprised 66 silicosis and 38 coal worker' pneumoconiosis (CWP). A total of 122 workers exposed to same dusts as the patients but without pneumoconiosis including 77 exposed to silica dusts and 45 to coal dusts were selected. The patients and the controls had the same dust exposure history. The peripheral venous blood was drawn from each subject. The IL-6 (-634C/G) genetic polymorphisms were detected by polymerase chain reaction restriction fragment length polymorphisms (PCR-RFLP) techniques. RESULTS: The frequencies of IL-6 (-634C/G) (CC, CG and GG) genotypes were 66.7%, 19.7% and 13.6% in silicosis group, 42.9%, 42.9% and 14.2% in silica dust exposure group, 73.7%, 18.4% and 7.9% in CWP group, 51.1%, 35.6% and 13.3% in coal dust exposure group respectively. The statistical analysis indicated that there was significant difference in the frequencies of IL-6 (-634C/G) (CC, CG and GG) genotypes between silicosis patients and workers exposed to silica dusts (P < 0.05). CONCLUSION: IL-6 (-634 C/G) genetic polymorphisms might play a role in the occurrence of silicosis.

[Novel mutations of potassium channel KCNQ1 S145L and KCNH2 Y475C genes in Chinese pedigrees of long QT syndrome].

OBJECTIVE: Hereditary long QT syndrome (LQTS) is a cardiac disorder characterized by prolongation of QT interval on electrocardiograms (ECGs) and syncope and sudden death caused by a specific multi-polymorphic ventricular tachyarrhythmia known as torsade de pointes. LQTS is caused by mutations in cardiac sodium channel gene SCN5A; potassium channel subunit genes KCNQ1, KCNH2, KCNE1, KCNE2, KCNJ2; calcium channel gene Cav2.1. and ankyrin-B gene ANK2. METHODS: We characterized 77 Chinese LQTS patients with clinical manifestations and mutations in the main LQTS genes, KCNQ1 and KCNH2 using PCR and sequence analysis. RESULTS: The spectrum of ST-T-wave patterns of 24 (31.2%) probands were considered as LQT1, 42 (54.5%) as LQT2 and 3 (3.9%) as LQT3. The remaining 8 (10.3%) could not be characterized. The average age for this population of LQTS patients was (27.6 +/- 16.4) years and the average QTc (561 +/- 70) ms, and the age of the first syncopal attack was (17.6 +/- 14.7) years. The triggering factors for cardiac events happening in these mutation carriers included physical exercise, emotional excitement and auditory irritation. We identified 4 KCNQ1 mutations and 7 KCNH2 mutations. Six of them were first identified with some data already shown. In this paper we showed the data of 6 other mutations. CONCLUSIONS: LQT2 is the most common type of LQTS in Chinese; 2 mutations of KCNQ1 and KCNH2 were first identified in this report; there are some differences between Chinese and North American or European LQTS patients in clinical characters and ECG.

[The characteristics during exercise test in long QT syndrome patients and the effects of left cardiac sympathetic denervation].

OBJECTIVE: To explore the mechanism of the left cardiac sympathetic denervation (LCSD) surgery to reduce the incidence of cardiac events for long QT syndrome (LQTS) patients. METHODS: 12 LQTS patients were selected to do exercise test (ET) to mimic sympathetic activation. The dynamic alterations on ECG during exercise and recovery phases (Rec) were observed and the exercise test characteristics for LQTS patients before and after surgery were summarized and compared. RESULTS: The QTc at resting was shortened from 0.54 s +/- 0.04 s to 0.50 s +/- 0.04 s, P = 0.026, while the maximum heart rate during exercise decreased from 141 beat/min +/- 18 beat/min to 124 beat/min +/- 14 beat/min, P = 0.003. QTc was shortened during exercise, however, it was prolonged during the early recovery phase (before ET 0.54 s +/- 0.02 s, ET 10 min 0.46 s +/- 0.02 s, Rec 4 min 0.55 s +/- 0.03 s); LCSD could reduce such abrupt alteration of QTc during early recovery phase (after surgery: before ET 0.53 s +/- 0.03 s, ET 10 min 0.48 s +/- 0.03 s, Rec 4 min 0.53 s +/- 0.05 s). QT/RR interval slope, representing the adaptation response of QT interval to heart rate, became steeper after exercise (from 0.61 +/- 0.06 to 0.71 +/- 0.07 after exercise, P < 0.01). LCSD made the slopes become less steep both before exercise (from 0.61 +/- 0.06 before surgery to 0.55 +/- 0.07 after surgery, P = 0.013) and after exercise (from 0.71 +/- 0.07 before surgery to 0.66 +/- 0.06 after surgery, P = 0.018). Notched T wave alterations occurred in 7 patients at the end of exercise and/or during early recovery phase before surgery, and LCSD diminished such alteration in 4 patients. CONCLUSION: The slope between QT and RR both the pre-exercise and post-exercise slopes, interval becomes less steep after LCSD, which suggests that exaggerated delay in repolarization with decreasing heart rate for LQTS patients is improved by LCSD. This may be one of the mechanisms of LCSD efficacy for treating LQTS patients. Exercise test is one of tools to evaluate the effect of LCSD on LQTS patients.

[Relationship between pneumoconiosis and the polymorphisms of HLA-DRB1*, DQB1* genes].

OBJECTIVE: To explore the relationship between the polymorphism of HLA-DRB1*, DQB* genes and the susceptibility of pneumoconiosis. METHODS: 1:1 case-control study was adopted. one hundred and thirteen cases of I grade pneumoconiosis were investigated. The control group were workers exposed to dust, who were the same sex, nationality, work place, time of beginning exposure and the cumulative exposure ages not over 2 years. PCR-SSP was used to detect 9 alleles in HLA-DRB1*, DQB1*. Information on related factors of pneumoconiosis was collected using a questionnaire. Univariate and multivariate logistic regression analysis were carried out with 1:1 case-control methodology. RESULTS: The frequency of HLA-DRB1*08 allele in case group was significantly higher than that of the controls (OR: 6.000; 95% CI: 1.9060 - 18.9414). The frequencies of HLA-DRB1*09, HLA-DQB1*06 in case group were significantly lower than those of the controls (OR: 0.259, 0.300; 95% CI: 0.1436 - 0.6268, 0.1149 - 0.5837 respectively). There were significant relationship between HLA-DRB1*08, HLA-DRB1*09, HLA-DQB1*06 alleles and pneumoconiosis after adjusting age, smoking, beginning age of exposure and cumulative length of exposure with multivariate logistic regression analysis (OR: 7.804, 0.225, and 0.269; 95% CI: 2.077 - 29.307, 0.083 - 0.609 and 0.117 - 0.613 respectively. Survival analysis showed that HLA-DQB1*06 allele was a protective factor and HLA-DRB1*08 allele was a risk factor for affecting pneumoconiosis latent period. CONCLUSION: HLA-DRB1*08 allele may be the susceptible risk gene for pneumoconiosis. HLA-DQB1*06 may be the protective gene against developing pneumoconiosis.

Electrical heterogeneity of canine right ventricular transient outward potassium currents.

BACKGROUND: Some studies have confirmed that the right ventricular walls of most rodents, such as canines and humans, have evident transient outward potassium current (Ito1) heterogeneity, and this heterogeneity is closely related to J point elevation, J wave formation, and some ventricular tachycardias such as ventricular fibrillations caused by Brugada syndrome. This study is designed to investigate transmural electrical heterogeneity of the canine right ventricle during repolarization (phase 1) from the viewpoint of 4-aminopyridine sensitive and calcium-independent Ito1. METHODS: Adult canine single right ventricular epicardial (Epi) cells, mid-myocardial (M) cells, and endocardial (Endo) cells were enzymatically dissociated. Whole cell voltage-clamp recordings were made to compare the Ito1 values of the three cell types. RESULTS: At 37 degrees C and using 0.2 Hz and +70 mV depolarizing test potentials, the average peak Ito1 values of Epi cells and M cells averaged (4070 +/- 1720) pA and (3540 +/- 1840) pA, respectively. The activated and inactivated Epi and M cells kinetic processes were in accordance with the Boltzmann distribution. Compared with Ito1 in Epi cells and M cells, the average peak Ito1 in Endo cells was very low, averaged (470 +/- 130) pA. CONCLUSIONS: These results suggest that there are evident differences and potent gradients in Ito1 between the three cardiac cell types, especially between Epi and Endo cells. These differences are among the prominent manifestations of right ventricular electrical heterogeneity, and may form an important ionic basis and prerequisite for some malignant arrhythmias in the right ventricle, including those arising from Brugada syndrome and other diseases.

[Differential acute mortality among the allozyme genotypes of Oxya chinensis by pesticide avermectin].

The rice grasshopper Oxya chinensis exhibits polymorphic loci at Ldh, Gpi, Pgm and Me. The data of the mean number of alleles per locus (A = 2.8), percentage of polymorphic loci (P = 80.0%), the observed mean heterozygosities (Ho = 0.271 approximately 0.279) and the expected mean heterozygosities (He = 0.305 approximately 0.316) of the species suggest that O. chinensis possesses sufficient genetic diversity. It was hypothesized that the high polymorphisms at Ldh, Gpi, Pgm and Me might make it possible for pesticide avermectin to act as a selective agent through differential lethality among the insect individuals with different genotypes. In this study a total of 855 grasshoppers were injected with avermectin (1.3 x 10(-2) g/g) to obtain a mortality of 54% after 24 hours. The allozyme analysis was then employed to determine the genotypes of Ldh, Gpi, Pgm and Me for both dead and surviving individuals. Contingency table chi2 tests showed that avermectin displayed random lethal effects on the genotypes at the loci of Ldh, Pgm and Me, without correlation between the genotype and mortality. In contrast, at Gpi locus, the grasshopper demonstrated a mortality cline of Gpi-AA (38%), Gpi-AB (51%), Gpi-BB (58%) and Gpi-BC (74%). The significant mortality differences were found among the following genotype pairs: Gpi-AA vs. Gpi-BB, Gpi-AA vs. Gpi-BC and Gpi-AB vs. Gpi-BC. These data implied the Gpi-AA genotype was likely related to the specie's resistance to the pesticide avermectin. It was also noted that the Gpi-A allele was present in the genotypes with low morality,while Gpi-B was present in the genotypes with moderate mortality, and the individuals with Gpi-C allele exhibited the highest mortality. The data obtained in this study suggested that the increasing proportion of Gpi-AA genotype and perhaps Gpi-A allele in a population may be useful as a potential resistant biomarker of O. chinensis to pesticide avermectin.