[Safety and effectiveness of emergency stenting for acute anterior circulation large artery disease].

Objective: To explore the safety and effectiveness of early stent implantation in patients with acute anterior circulation large artery disease. Methods: Patients were recruited from the RESCUE-RE study (a registration study for Critical Care of Acute Ischemic Stroke After Recanalization). Patients who were diagnosed with acute ischemic stroke within 24 hours of onset and given endovascular treatment after consultation from July 2018 to May 2019 from 18 sub-centers nationwide were retrospectively enrolled. According to whether the stents were placed during the operation, the patients were divided into two groups: stenting group and non-stenting group. The baseline between the two groups was matched by propensity score. The matching variables included age, sex, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline Glasgow Coma Scale (GCS) score, history of stroke, smoking and onset to hospital time. The primary clinical outcome was 90-day good neurological outcome [defined as modified Rankin score (mRS) 0-2]. Secondary outcomes include 90-day mortality, 24-hour re-occlusion of the responsible artery, and symptomatic intracranial hemorrhage. The differences in clinical endpoints between the two groups were compared. Result: A total of 899 patients with acute anterior circulation artery stenosis or occlusion were included in the study, with a mean age of(66±12)years,and 532(59.18%) were male. There were 193 patients in the stenting group and 706 patients in the non-stenting group. After the baseline data between the two groups were matched by propensity score, 169 patients were enrolled in each of two groups respectively. After matching, the proportion of patients in the stenting group with etiological diagnosis of large atherosclerosis [82.53% (137/166) vs 55.69% (93/167)] and the proportion of patients with previous history of hypertension [63.31% (107/169) vs 47.93% (81/169)] in the stenting group were higher than those in the non-stenting group (both P<0.05). While the proportion of patients in the non-stenting group with cardiogenic embolism [37.73%(63/167) vs 11.45%(19/166)]and the proportion of patients with atrial fibrillation [18.93% (32/169) vs 10.65%(18/169)]was higher(all P<0.05). In the stenting group, the time from onset to recanalization was longer[519 (408, 620)min vs 469 (365, 690)min], and the proportion of general anesthesia [50.89% (86/169) vs 35.50% (60/169)] was higher in the stenting group(both P<0.05). In addition, in the stenting group, the proportion of patients receiving mechanical thrombectomy[67.46% (114/169) vs 88.76% (150/169)] and arterial thrombolysis [2.37% (4/169) vs 18.93% (32/169)] was lower than non-stenting group during the operation, while the proportion of patients receiving balloon dilation [53.85% (91/169) vs 13.61% (23/169)]was higher(both P<0.05). The proportion of patients in stent group receiving antiplatelet drugs before operation was higher [13.46% (21/169) vs 8.70% (14/169)](both P<0.05). In terms of clinical outcome, compared with the non-stenting group, the proportion of patients in the stenting group with good neurological function in 90 days was lower [44.79% (73/169) vs 56.36% (93/169)], and the proportion of death at 90 days was higher[15.98% (27/169) vs 8.88% (15/169)] (both P<0.05). There was no significant difference between the two groups in 24-hour re-occlusion[8.88% (15/169) vs 9.47% (16/169)] and symptomatic intracranial hemorrhage[5.92% (10/169) vs 4.76% (8/169)](both P>0.05). Conclusion: For patients with acute anterior circulation artery disease, early stent therapy may increase the proportion of patients with adverse neurological outcomes.

[Three cases of acute chlorfenapyr poisoning].

This paper reported 3 cases of poisoning caused by chlorfenagyr. Chlorfenapyr poisoning has gradually increased in clinical practice. The early stage after poisoning is digestive tract symptoms, followed by sweating, high fever, changes in consciousness, changes in myocardial enzymology, etc. Its main mechanism of intoxication is uncoupling oxidative phosphorylation. Since there is no specific antidote after poisoning, the fatality rate of chlorfenapyr poisoning remains high. The therapeutic measures are early gastrointestinal decontamination, symptomatic and supportive treatments, and early blood purification may be an effective treatment.

[The association between stress hyperglycemia ratio and outcome of patients with acute ischemic stroke undergoing endovascular treatment].

Objectives: To investigate the correlation between stress hyperglycemia ratio (SHR) and outcomes in patients with acute ischemic stroke treated with endovascular treatment. Methods: In a multicenter registration study for RESCUE-RE (a registration study for critical care of acute ischemic stroke after recanalization), eligible patients with large vessel occlusion stroke within 24 hours after onset who received endovascular treatment between July 2018 and May 2019 were enrolled. SHR was calculated as the fasting glucose concentration divided by the estimated average glucose concentration and then categorized into four groups according to the quartiles (group Q1, group Q2, group Q3 and group Q4). The primary outcome was poor neurological outcomeat day 90 fromstroke onset [defined as modified Rankin scale (mRS) of 3-6]. Secondary outcomes included early neurological deterioration (END), death within 3 months after stroke onset, and symptomatic intracranial hemorrhage.Multivariable logistic and Cox regression modelswere used to assess the correlation between quartiles of SHR and prognosis in patients with endovascular treatment. Results: A total of 592 patients were enrolled in the study, with a mean age of (63±12) years, and 68.07% were male.The median National Institute of Health stroke scale(NIHSS) score on admission was15(11, 20), and the median SHR was 1.23 (1.07, 1.47), with SHR<1.07 in group Q1, 1.07≤SHR<1.23 in group Q2, 1.23≤SHR<1.47 in group Q3 and SHR≥1.47 in group Q4, respectively. The rate of complete recanalization was lower in group Q4 than that of group Q1 (70.27% vs 83.67%, P=0.026). After fully adjusted for potential covariates, the risk of poor neurological outcome at day 90 from stroke onset in group Q4 was 2.38 folds that of group Q1(adjusted OR= 2.38, 95%CI: 1.57-3.57,P=0.003). The risk of death within 3 months of patients in group Q4 was 1.80 times that of the patients in group Q1, but the difference was not statistically significant(adjusted HR=1.80, 95%CI: 0.90-3.62, P=0.098). Conclusion: Higher SHR was correlated with poor neurological outcome at 3 months in large artery occlusion related acute ischemic stroke patients receiving endovascular therapy.

[Interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats].

Objective: To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats. Methods: In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO2) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO2 model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO2 by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO2 model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO2 exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-ß1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1ß) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results: Compared with the negative control group, SiO2 model group had a significant decrease in the body weight of rats (P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α, IL-1ß were all significantly increased (P<0.05) . Compared with the SiO2 model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly (P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-ß1, TNF-α and IL-1ß were significantly decreased (P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO2 model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased (P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased (P<0.05) . Conclusion: Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO2 dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

[Association studies between postoperative hypoeosinophilia and hospital stay in patients undergoing hip fracture surgery under different anesthesia].

Objective: To investigate early postoperative changes in eosinophils (EOS) and the relationship of postoperative hospital stay and hypoeosinophilia in patients undergoing hip fracture surgery under general or spinal anesthesia. Methods: The clinical data of patients who underwent hip fracture surgery at Beijing Tiantan Hospital between April 2014 and November 2017 were retrospectively analyzed. Patients were classified according to whether they received general anesthesia or spinal anesthesia. Univariate regression analysis was used to examine a number of covariates potentially contributed to postoperative hospital stay. Multivariate linear regression was used to analyze the relationship between postoperative day 1 EOS counts and postoperative hospital stay. Interaction and stratified analyses were conducted according to anesthesia methods. Results: A total of 149 patients were included in this study. Thirty-four of them underwent general anesthesia and 115 of them underwent spinal anesthesia. The postoperative day 1 EOS of the general anesthesia group was 0 (0,1.8)×107/L, which was lower than that of the spinal anesthesia group 1.0(0,6.0)×107/L (Z=3.095, P<0.01). After adjusting the confounders of age, gender, American Society of Anesthesiologists (ASA) grade, intraoperative blood loss, intraoperative red blood cell (RBC) transfusion, postoperative day 1 hematocrit (HCT) and white blood cell (WBC), postoperative complications, and the interaction terms for ASA, intraoperative blood loss, intraoperative RBC transfusion and postoperative complications, the negative correlation between postoperative hospital stay and postoperative day 1 EOS level was significant (ß=-0.39, 95%CI:-0.74--0.05, P<0.05) in the general anesthesia group. Conclusion: EOS were significantly decreased after surgery in general anesthesia group, and the postoperative hospital stay was negatively correlated with postoperative day 1 hypoeosinophilia.

[Transmission electron microscopic observation on gonad of Oncomelania hupensis offspring bred in Weishan Lake areas].

OBJECTIVE: To observe the morphological changes in the testes and ovaries of adult 12th-generation Oncomelania hupensis bred for 12 winters in Weishan Lake areas. METHODS: The offspring of the adult O. hupensis snails bred in the Weishan Lake that were originated from the Yangzhou section of the Yangtze River was defined as the experiment group, while uninfected, adult O. hupensis snails captured from the marshland of the Yangzhou section of the Yangtze River served as the control group. Snails were dissected and intact testicular and ovarian specimens were sampled, routinely fixed, dehydrated, embedded, polymerized in an oven and sliced on an ultramicrotome. The sections were visualized under a transmission electron microscope, and the ultrastructure of the snail gonad was compared between the experiment and control groups. RESULTS: Transmission electron microscopy showed "9 + 2" microtubules on the transverse sections of the tails of sperm cells in the testes of male snails in the control group, with triangular acrosomes and spiral, dense nuclei seen in the tip, while in the experiment group, the "9 + 2" microtubules disappeared on the transverse sections of the tails of sperm cells in the testes of male snails, with low chromatin density found in the tip. Transmission electron microscopy revealed clear nucleolus and nuclear membranes in the ova of female snail ovaries, and displayed yolk body, liposomes and endoplasmic reticulum in the cytoplasm, bilayer twists of nuclear membrane and a uniform nucleolus in the control group, while in the experiment group, smooth nuclear membrane and unclear nucleolus were observed in the ova of female snail ovaries, with few contents seen within cells. CONCLUSIONS: Following breeding for 12 winters in the Weishan Lake, the 12th-generation O. hupensis snails fail to fully adapt to the natural environment in northern China, and the remarkable changes in the ultrastructure of the snail gonad may be a cause of gradual decline and even extinction of O. hupensis in the Weishan Lake areas.

TUG1 promotes diabetic atherosclerosis by regulating proliferation of endothelial cells via Wnt pathway.

OBJECTIVE: To explore the specific role of TUG1 in regulating the occurrence and progression of diabetic atherosclerosis and its underlying mechanism. PATIENTS AND METHODS: TUG1 expressions in coronary artery disease (CAD) tissues, normal arterial tissues, endothelial cells induced by high-dose glucose and tumor necrosis factor-α (TNF-α) were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The effects of TUG1 on proliferation, migration and cell cycle of human umbilical vein endothelial cells (HUVECs) were detected by cell counting kit-8 (CCK-8), transwell assay and flow cytometry, respectively. Subsequently, protein expressions of proliferation-related genes, cell cycle-related genes and Wnt pathway-related genes were detected by Western blot after altering TUG1 expression in HUVECs. Further rescue experiments were carried out to explore whether TUG1 could regulate diabetic atherosclerosis via Wnt pathway. RESULTS: Overexpressed TUG1 was found in CAD tissues and endothelial cells induced by high-dose glucose and TNF-α compared with those of controls. TUG1 overexpression remarkably promoted proliferation, migration and cell cycle of HUVECs. Protein expressions of ß-catenin and c-Myc were upregulated by overexpression of TUG1. Rescue experiments indicated that XAV-939, the inhibitor of Wnt pathway, could partially reverse the increased proliferative and migratory changes in HUVECs induced by TUG1 overexpression. CONCLUSIONS: We found that overexpressed TUG1 stimulates proliferation and migration of endothelial cells via Wnt pathway, thereby promoting the occurrence and progression of diabetic atherosclerosis.

Expressions of VEGF and miR-21 in tumor tissues of cervical cancer patients with HPV infection and their relationships with prognosis.

OBJECTIVE: To investigate the expressions of vascular endothelial growth factor (VEGF) and micro-ribonucleic acid-21 (miR-21) in cervical cancer patients with human papillomavirus (HPV) infection and determine the potential relationships with prognosis. PATIENTS AND METHODS: Expressions of VEGF in cervical cancer tissues and cancer-adjacent tissues were detected by immunohistochemistry, and the expressions of miR-21 and VEGF in both tissues were quantitatively analyzed using reverse transcription polymerase chain reaction (RT-PCR). Patients with cervical cancer were followed up after operation, and the survival rates of patients with different expression levels of miR-21 and VEGF were compared. RESULTS: VEGF was expressed in both cervical cancer tissues and cancer-adjacent tissues. The positive expression rate of VEGF in cervical cancer tissues (75.69%) was significantly higher than that in cancer-adjacent tissues (10.45%). RT-PCR results showed that the expression levels of miR-21 and VEGF in cervical cancer tissues were significantly higher than those in cancer-adjacent tissues (p<0.05). Correlation analyses revealed that miR-21 expression was significantly positively correlated with VEGF expression in cervical cancer tissues (r2=0.4174, p<0.0001). Prognostic analyses showed that the 5-year survival rate of patients was relatively high when miR-21 and VEGF were lowly expressed. CONCLUSIONS: VEGF and miR-21 are highly expressed in tumor tissues of cervical cancer patients with HPV infection. VEGF expression is significantly positively correlated with miR-21 expression, and the high levels of VEGF and miR-21 predict unfavorable prognosis of cervical cancer. Data provide a theoretical support for clinical treatment of cervical cancer patients with HPV infection.

Safety and pharmacodynamic mechanism of ropivacaine lumbar anesthesia in Cesarean section.

Lumbar anesthesia is the preferred anesthetic approach for puerperae undergoing cesarean section in China. To observe the safety of administering different doses of ropivacaine for cesarean section and its pharmacodynamic mechanism, we randomly divided 180 pregnant women undergoing cesarean section into three groups: group A, 10 mg ropivacaine (0.50%); group B, 12 mg ropivacaine (0.50%); and group C, 14 mg ropivacaine (0.50%). Pharmacodynamic index, anesthesia quality and incidence of untoward reactions of each group were observed. Group A performed the poorest and group C the best in evaluation of sensory and motory block (P less than 0.05). With regard to evaluation of hemodynamic index, hemodynamic parameters of the three groups had significant differences after medication; mean arterial pressure (MAP) of patients in group B decreased at time points T1, T2 and T3 and heart rate (HR) became much higher at T1 (P less than 0.05); MAP of the patients in group C decreased at T1, T2, T3 and T4, but HR became higher at T1 and T2 (P less than 0.05); HR of group B was higher than that of group A at T1 (P less than 0.05); MAP of the patients in group C had a significant decrease at T1, T2, T3 and T4, but HR became higher at T2 (P less than 0.05); MAP of patients in group C significantly decreased compared to group B at T1 and T2, but HR became higher at T2 (P less than 0.05). Fluctuation of oxyhemoglobin saturation (SpO2) of all patients was between 95% and 99%. There was no occurrence of myocardial ischemia or arrhythmia. 1-min Apgar score of neonates of the three groups had no significant difference (P0.05). The incidence of adverse reactions of the patients in group C was much higher than that of the patients in the other groups (P less than 0.05). Twelve mg ropivacaine (5%) is the most suitable dose for pregnant women undergoing cesarean section as it can achieve a sound anesthetic effect and high safety and, moreover, has little influence on respiratory and circulatory functions.

[Advances of self-healing dental composite resin].

Degradation of composite resin during ageing always produces micro-cracks, the latter could gradually expand, leading to the fracture of tooth restoration. In order to extend the service life of composite resin by repairing cracks intelligently, self-healing microcapsule models have been introduced in resin-based dental materials. This paper will present the concept and classification of self-healing materials, and review the research progresses on self-healing dental resin.

Obesity is an independent risk factor for non-alcoholic fatty liver disease: evidence from a meta-analysis of 21 cohort studies.

BACKGROUND: The association between obesity and nonalcoholic fatty liver disease (NAFLD) has not been fully quantified, and the magnitude of NAFLD risk associated with obesity is still unclear. A meta-analysis of cohort studies was performed to elucidate the NAFLD risk associated with obesity. METHODS: Pubmed, Web of Science and Embase were searched for cohort studies assessing NAFLD risk associated with obesity or increased body mass index (BMI). Relative risks (RRs) with 95% confidence intervals (95%CIs) were pooled using random-effects model of meta-analysis. RESULTS: Twenty-one cohort studies including 13 prospective studies and 8 retrospective studies were finally included. There were a total of 381,655 participants in the meta-analysis. Compared with normal weight, obesity independently led to a 3.5-fold increased risk of developing NAFLD (RR = 3.53, 95%CI 2.48 to 5.03, P < 0.001). Meta-analysis also suggested an obvious dose-dependent relationship between BMI and NAFLD risk (per 1-unit increment in BMI: RR = 1.20, 95%CI 1.14 to 1.26, P < 0.001). Subgroup analyses further identified the robustness of the association above. No obvious risk of publication bias was observed. CONCLUSION: Obese individuals have a 3.5-fold increased risk of developing NAFLD, and there is an obvious dose-dependent relationship between BMI and NAFLD risk. © 2016 World Obesity.

CD44v6 expression in patients with stage II or stage III sporadic colorectal cancer is superior to CD44 expression for predicting progression.

BACKGROUND: Currently, it is difficult to predict the prognosis of patients exhibiting stage II or stage III colorectal cancer (CRC) and to identify those patients most likely to benefit from aggressive treatment. The current study was performed to examine the clinicopathological significance of CD44 and CD44v6 protein expression in these patients. STUDY DESIGN: We retrospectively investigated 187 consecutive patients who underwent surgery with curative intent for stage II to III CRC from 2007 to 2013 in the Beijing Civil Aviation Hospital. CD44 and CD44v6 protein expression levels were determined using immunohistochemistry and compared to the clinicopathological data. RESULTS: Using immunohistochemical detection, CD44 expression was observed in 108 (57.75%) of the CRC patients; and its detection was significantly associated with greater invasion depth, lymph node metastasis, angiolymphatic invasion, and a more advanced pathological tumor-lymph node-metastasis (TNM) stage. CD44v6 expression was observed in 135 (72.19%) of the CRC patients; and its expression was significantly associated with a poorly differentiated histology, greater invasion depth, lymph node metastasis, angiolymphatic invasion, and a more advanced pathological TNM stage. Expression of CD44v6 was higher than that of CD44 in stage II and stage III sporadic CRC. CONCLUSION: CD44v6 is a more useful marker for predicting a poor prognosis in stage II and stage III sporadic CRC as compared to CD44.

Multicenter, double-blind, randomized clinical trial of parenterally administered Cefoselis versus Cefepime for the treatment of acute bacterial infections.

AIM: This study aims to evaluate the clinical efficacy and safety of intravenous Cefoselis injection for the treatment of acute moderate and severe bacterial infections. PATIENTS AND METHODS: A multicenter, double-blind, randomized clinical trial was carried out using Cefepime as control. Patients received 1.0 g of either Cefoselis or Cefepime for moderate infections or 2.0 g for severe infections at an interval of 12 hours for 7 to 14 days. A total of 276 patients (138 with Cefoselis, 138 with Cefepime) with respiratory or urinary tract infections were enrolled in the study. Up to 137 and 124 patients receiving Cefoselis and 132 and 125 patients receiving Cefepime were eligible for the ITT (intent to treat) and PP (per protocol) analyses, respectively. RESULTS: At the end of the treatment, the cure rates and effective rates were 59.68% (74/124) and 93.55% (116/124) with Cefoselis, and 56.00% (74/124) and 90.40% (116/124) with Cefepime. The bacterial eradication rates of the two groups were 90.32% and 93.85%, respectively. No statistical differences were observed on the above-mentioned parameters between the two groups (all p > 0.05). Adverse events, mainly mild aminotransferase elevation and mild leukopenia, were observed in 11.59% (16/138) and 13.77% (19/138) of patients with Cefoselis and Cefepime, respectively (p > 0.05). CONCLUSIONS: Cefoselis is an effective and safe choice against acute moderate and severe respiratory infections and UTI (urinary tract infection).

Clinical analysis of optimal timing for application of noninvasive positive pressure ventilation in treatment of AECOPD patients.

OBJECTIVES: This study is conducted to investigate an optimal timing of sequential noninvasive positive pressure ventilation (NPPV) applied for patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). PATIENTS AND METHODS: Application of NPPV for 102 patients was randomly observed in the conditions of a 2-hour spontaneous breathing trial (SBT-2) and pulmonary infection control (PIC) window. Efficiency of NPPV in treatment of the patients, an incidence rate of tracheal reintubation, length of time for patients received invasive mechanical ventilation, and a morbidity rate of ventilator-associated pneumonia were examined in each group of 51 patients. RESULTS: The incidence rates for the patients treated successfully with NPPV and for tracheal reintubation were shown as 88.2 and 60.8, and 11.8 and 39.2 in SBT-2 and PIC, respectively (both p < 0.05). Length of time (hour) for use of the invasive ventilation was 116 and 82.5 in SBT-2 and PIC, respectively (p < 0.05). There was a similar morbidity rate of ventilator-associated pneumonia seen in both groups. CONCLUSIONS: SBT-2 would be the optimal timing considered to use NPPV for AECOPD patients based on a high success rate and a low risk of tracheal reintubation.

The structure and possible functions of the milkfish Chanos chanos adipose eyelid.

Basic histological sections (with different staining methods) and scanning electron microscopy (SEM) examinations showed that there were three distinctive layers in the adipose eyelid of milkfish Chanos chanos, which is found in the cephalie region and covers the entire eye. The outer and inner layers were epithelial tissues and the middle layer was composed of connective tissue formed by type I collagen fibrils. No adipose tissue was found in any of the three layers of the so-called adipose eyelid. Examination by transmission spectrophotometer showed that the adipose tissue could filter out ambient light with a wavelength shorter than 305 nm. A photoretinoscope was used to investigate whether the adipose eyelid influenced the mechanism of eye focusing. Eye diopter values did not differ before or after eyelid removal, which indicated that the adipose eyelid did not play a role in eye focusing. In light of these findings, it is suggested that the adipose eyelid serves to block exposure of harmful ultraviolet light into eyes and may also to offer some protection against impact to the eye in the aquatic environment.

A histochemical study on the snout tentacles and snout skin of bristlenose catfish Ancistrus triradiatus.

Histological sections of the tentacles of Ancistrus triradiatus revealed that they contain many goblet cells with granule-like sections distributed along the edge of the tentacles (mean 302 cells mm(-1)). Various histochemical methods were used to characterize the contents of the goblet cells. The results indicated that the contents were periodic acid-Schiff (PAS) positive, glycogen negative and no sulphated mucins could be found. The contents of the goblet cells were acid mucins and O-acetylated sialomucins which had high energy content. The snout skin of the male also contained goblet cells with higher density (mean 755 cells mm(-1)) than that of the tentacles. Snout skin of female A. triradiatus, on the contrary, did not contain any goblet cells. Instead, many minute spines could be found. Based on the acid mucins and O-acetylated sialomucins secretions of goblet cells which are of high nutritional values, it is hypothesized that snout tentacle secretions are used to provide nutrients to fish larvae when they are under paternal care.

Endosperm-specific hypomethylation, and meiotic inheritance and variation of DNA methylation level and pattern in sorghum (Sorghum bicolor L.) inter-strain hybrids.

Understanding dynamics and inheritance of DNA methylation represents important facets for elucidating epigenetic paradigms in plant development and evolution. Using four sets of sorghum (Sorghum bicolor L.) inter-strain hybrids and their inbred parents, the developmental stability and inheritance of cytosine methylation in two tissues, leaf and endosperm, by MSAP analysis were investigated. It was found that in all lines (inbred and hybrid) studied, endosperm exhibited a markedly reduced level of full methylation of the external cytosine or both cytosines at the CCGG sites relative to leaf, which caused a variable reduction in the estimated total methylation level in endosperm by 6.89-19.69% (11.47% on average). For both tissues, a great majority of cytosine methylation profiles transmitted to F1 hybrids, however, from 1.69 to 3.22% of the profiles showed altered patterns in hybrids. Both inherited and altered methylation profiles can be divided into distinct groups, and their frequencies are variable among the cross-combinations, and between the two tissues. The variations in methylation level and pattern detected in the hybrids were not caused by parental heterozygosity, and they could be either non-random or stochastic among hybrid individuals. Homology analysis of isolated bands that showed endosperm-specific hypomethylation or variation in hybrids indicated that diverse sequences were involved, including known-function cellular genes and mobile elements. RT-PCR analysis of six genes representing endosperm-specific hypomethylation in MSAP profiles indicated that all showed higher expression in endosperm than in leaf, suggesting involvement of methylation state in regulating tissue-specific or tissue-biased expression in sorghum. Analysis on leaf-RNA from 5-azacytidine-treated plants further corroborated this possibility.

The hearing abilities of the prawn Palaemon serratus.

The mechanism of sound reception and the hearing abilities of the prawn (Palaemon serratus) have been studied using a combination of anatomical, electron microscopic and electrophysiological approaches, revealing that P. serratus is responsive to sounds ranging in frequency from 100 to 3000 Hz. It is the first time that the Auditory Brainstem Response (ABR) recording technique has been used on invertebrates, and the acquisition of hearing ability data from the present study adds valuable information to the inclusion of an entire sub-phylum of animals when assessing the potential impact of anthropogenic underwater sounds on marine organisms. Auditory evoked potentials were acquired from P. serratus, using two subcutaneous electrodes positioned in the carapace close to the supraesophageal ganglion and the statocyst (a small gravistatic organ located below the eyestalk on the peduncle of the bilateral antennules). The morphology of the statocyst receptors and the otic nerve pathways to the brain have also been studied, and reveal that P. serratus possesses an array of sensory hairs projecting from the floor of the statocyst into a mass of sand granules embedded in a gelatinous substance. It is the purpose of this work to show that the statocyst is responsive to sounds propagated through water from an air mounted transducer. The fundamental measure of the hearing ability of any organism possessing the appropriate receptor mechanism is its audiogram, which presents the lowest level of sound that the species can hear as a function of frequency. The statocyst of P. serratus is shown here to be sensitive to the motion of water particles displaced by low-frequency sounds ranging from 100 Hz up to 3000 Hz, with a hearing acuity similar to that of a generalist fish. Also, recorded neural waveforms were found to be similar in both amplitude and shape to those acquired from fish and higher vertebrates, when stimulated with low-frequency sound, and complete ablation of the electrophysiological response was achieved by removal of the statocyst.

Acoustic communication in two freshwater gobies: the relationship between ambient noise, hearing thresholds and sound spectrum.

Two freshwater gobies Padogobius martensii and Gobius nigricans live in shallow (5-70 cm) stony streams, and males of both species produce courtship sounds. A previous study demonstrated high noise levels near waterfalls, a quiet window in the noise around 100 Hz at noisy locations, and extremely short-range propagation of noise and goby signals. To investigate the relationship of this acoustic environment to communication, we determined audiograms for both species and measured parameters of courtship sounds produced in the streams. We also deflated the swimbladder in P. martensii to determine its effect on frequency utilization in sound production and hearing. Both species are maximally sensitive at 100 Hz and produce low-frequency sounds with main energy from 70 to 100-150 Hz. Swimbladder deflation does not affect auditory threshold or dominant frequency of courtship sounds and has no or minor effects on sound amplitude. Therefore, both species utilize frequencies for hearing and sound production that fall within the low-frequency quiet region, and the equivalent relationship between auditory sensitivity and maximum ambient noise levels in both species further suggests that ambient noise shapes hearing sensitivity.

Effects of underwater noise on auditory sensitivity of a cyprinid fish.

The ability of a fish to interpret acoustic information in its environment is crucial for its survival. Thus, it is important to understand how underwater noise affects fish hearing. In this study, the fathead minnow (Pimephales promelas) was used to examine: (1) the immediate effects of white noise exposure (0.3-4.0 kHz, 142 dB re: 1 microPa) on auditory thresholds and (2) recovery after exposure. Audiograms were measured using the auditory brainstem response protocol and compared to baseline audiograms of fathead minnows not exposed to noise. Immediately after exposure to 24 h of white noise, five out of the eight frequencies tested showed a significantly higher threshold compared to the baseline fish. Recovery was found to depend on both duration of noise exposure and auditory frequency. These results support the hypothesis that the auditory threshold of the fathead minnow can be altered by white noise, especially in its most sensitive hearing range (0.8-2.0 kHz), and provide evidence that these effects can be long term (>14 days).