[Forecasting the burden of disease from diabetes under the scenarios of specific risk factors control in China in 2030]

Objective: To forecast mortality, age-standardized mortality, and probability of premature mortality from diabetes, and to simulate the impact of controlling risk factors by 2030 in China. Methods: We simulated the burden of disease from diabetes in six scenarios according to the development goals of risk factors control by the WHO and Chinese government. Based on the theory of comparative risk assessment and the estimates of the burden of disease for China from the Global Burden of Disease Study 2015, we used the proportional change model to project the number of deaths, age-standardized mortality, and probability of premature mortality from diabetes under different scenarios of risk factors control in 2030. Results: If the trends in exposures to risk factors from 1990 to 2015 continued. Mortality, age-standardized mortality, and probability of premature mortality from diabetes would increase to 32.57/100 000, 17.32/100 000, and 0.84% by 2030, respectively. During that time, mortality, age-standardized mortality and probability of premature mortality for males would all be higher than for females. If the goals of controlling risk factors were all achieved, the number of deaths from diabetes in 2030 would decrease by 62.10% compared to the predicted numbers based on the historical trends in exposure to risk factors, and the probability of premature mortality would drop to 0.29%. If only the exposure to a single risk factor were achieved by 2030, high fasting plasma glucose control would have the greatest impact on diabetes, resulting in a 56.00% reduction in deaths compared to the predicted numbers based on the historical trends, followed by high BMI (4.92%), smoking (0.65%), and low physical activity (0.53%). Conclusions: Risk factors control plays an important role in reducing the number of deaths, age-standardized mortality rate, and probability of premature mortality from diabetes. We suggest taking comprehensive measures to control relevant risk factors for certain populations and regions, to achieve the goal of reducing the burden of disease from diabetes as expected.

[Prediction on the cardio-cerebrovascular death and probability of premature death caused by common risk factors in China in 2030]

Objective: Predictive models were used to evaluate the impact of common risk factors on the number of cardio-cerebrovascular deaths and the probability of premature death. Methods: Using the data for China estimated by the Global Burden of Disease study 2015 (GBD 2015), we calculated the population attribution fraction (PAF) of risk factors. The proportional change model was used to estimate the number of unattributable deaths by 2030, and to predict the number of deaths, mortality, standardized mortality and probability of premature death by 2030. Results: According to the natural change trend of risk factors from 1990 to 2015, the number of deaths and mortality would reach 6.12 million and 428.53/100 000 by 2030, with an increase of 59.92% and 52.87%. By 2030, the probability of premature death from cardio-cerebrovascular diseases among Chinese aged 30-70 years old would continue to decline, from 11.43% to 11.28% for men, and from 5.79% to 4.43% for women. If the goals of all included risk factors were reached by 2030, 2 289 200 cardio-cerebrovascular deaths would be avoided. If only the exposure to a single risk factor was achieved by 2030, blood pressure, total cholesterol, and fine particulate matter exposure were the three most important factors affecting cardio-cerebrovascular deaths, which would reduce 1 332 800, 609 100 and 306 800 deaths, respectively. Among the involved risk factors, the control of blood pressure would mostly decrease the number of deaths due to ischemic heart disease and hemorrhagic stroke, about 677 300 and 391 100 deaths, accordingly. Conclusion: The control of risk factors is of great significance in reducing deaths and probability of premature death due to cardio-cerebrovascular diseases. If the control targets of all risk factors could be achieved by 2030, the burden of cardio-cerebrovascular diseases would be reduced greatly.

[Prediction of disease burden caused by malignant cancer in the context of risk factor control in China, 2030]

Objective: To predict the number of deaths, standardized mortality and probability of premature mortality caused by malignant cancer in the context of risk factor control at different levels in China in 2030, and assess the possibility of achieving the target of reducing the probability of premature mortality of malignant cancer. Methods: According to the risk factor control standard for malignant cancer used both at home and abroad, the results of China from Global Burden of Disease Study 2015 were used to calculate the population attributable fraction of the risk factors. Based on the comparative risk assessment theory, the deaths of malignant cancer were classified as attributable deaths and un-attributable deaths. Proportional change model was used to predict risk factor exposure and un-attributable deaths of malignant cancer in the future, then the number of deaths, standardized mortality rate and probability of premature mortality of malignant cancer in 2030 was estimated. Data analyses were performed by using software R 3.6.1. Results: If the risk factor exposure level during 1990-2015 remains, the number of deaths, standardized mortality rate, and probability of premature mortality of malignant cancer would increase to 3.62 million, 153.96/100 000 and 8.92% by 2030, respectively. If the risk factor exposure control level meets the requirement, the probability of premature mortality from cancer in people aged 30-70 years would drop to 7.57% by 2030. Conclusions: The control of risk factor exposure will play an important role in reducing deaths, standardized mortality rate and probability of premature mortality of malignant cancer. But more efforts are needed to achieve the goals of Health China Action.

Diverging targets mediate the pathological roleof miR-199a-5p and miR-199a-3p by promoting cardiac hypertrophy and fibrosis

MicroRNA-199a-5p (miR-199a-5p) and -3p are enriched in the myocardium, but it is unknown whether miR-199a-5p and -3p are co-expressed in cardiac remodeling and what roles they have in cardiac hypertrophy and fibrosis. We show that miR-199a-5p and -3p are co-upregulated in the mouse and human myocardium with cardiac remodeling and in Ang-II-treated neonatal mouse ventricular cardiomyocytes (NMVCs) and cardiac fibroblasts (CFs). miR-199a-5p and -3p could aggravate cardiac hypertrophy and fibrosis in vivo and in vitro. PPAR gamma coactivator 1 alpha (Ppargc1a) and sirtuin 1 (Sirt1) were identified as target genes to mediate miR-199a-5p in promoting both cardiac hypertrophy and fibrosis. However, miR-199a-3p aggravated cardiac hypertrophy and fibrosis through targeting RB transcriptional corepressor 1 (Rb1) and Smad1, respectively. Serum response factor and nuclear factor κB p65 participated in the upregulation of miR-199a-5p and -3p in Ang-II-treated NMVCs and mouse CFs, and could be conversely elevated by miR-199a-5p and -3p. Together, Ppargc1a and Sirt1, Rb1 and Smad1 mediated the pathological effect of miR-199a-5p and -3p by promoting cardiac hypertrophy and fibrosis, respectively. This study suggests a possible new strategy for cardiac remodeling therapy by inhibiting miR-199a-5p and -3p.

[Evidence summary for postoperative hypothermia rewarming in adults with severe burns]

Objective: To retrieve, evaluate, and summarize the best evidence for postoperative hypothermia rewarming in adults with severe burns. Methods: Foreign language databases including Cochrane Library, Joanna Briggs Institute Evidence-Based Health Care Center Database, PubMed, Ovid-Medline, BMJ Best Practice, and Web of Science were retrieved with the search terms of " severe burn/major burn/severe degree burn" , " hypothermia/warming intervention/hypothermia/temperature/body temperature change" , and " postoperative /perioperative/peri-operative/post-operative" and Chinese databases including Chinese Journal Full-Text Database, Wanfang Database, and VIP Database were retrieved with the search terms of "//" , "/" , and "" to obtain all the publicly published evidence for postoperative hypothermia rewarming in adults with severe burns from the establishment of each database to April 2018, including systematic evaluations, guidelines, expert consensus, evidence summary, and original research closely related to the evidence. The literatures were screened and evaluated for their quality, the evidences were extracted from them, evaluated, classified in order to summarize the best evidences. Results: A total of 8 literatures were included, including one systematic evaluation, three guidelines, one expert consensus, and three evidence summaries. Finally, the best evidences in 8 aspects including the body temperature monitoring site, body temperature monitoring frequency, surface heating, in vivo heating, rewarming start, multi-strategy rewarming, equipment, and personnel training were summarized. Conclusions: Based in the evidence-based nursing method, this study retrieves and evaluates the literature, summarizes the evidence analysis and evaluation, and obtains the best evidences of postoperative hypothermia rewarming in adult patients with severe burns, which provides a strong reference for the clinical implementation of rewarming.

[Clinical experience of minimal invasive coronary surgery-coronary artery bypass grafting: a series of 244 cases]

Objective: To examine the safety and efficacy of minimally invasive coronary surgery-coronary artery bypass grafting (MICS-CABG). Methods: From the first case in November 2015 to November 2019, a total of 244 cases of MICS-CABG were performed in Department of Cardiovascular Surgery, Peking University Third Hospital. There were 197 males and 47 females, aging (62.3±8.7)years (range: 36 to 88 years). The operations were performed via the 5(th) intercostal space of left thoracic lateral incision (length: 4 to 5 cm extended for 8 to 10 cm), and were performed under off-pump, with the help of the chest wall suspension device and cardiac fixator. The proximal anastomosis on ascending aorta and the distal anastomosis of left anterior descending branch, circumflex branch and right coronary system were completed according to procedure. In all 244 cases, the proportion of 2 grafts was 53.7% (131 cases), 3 grafts was 36.1% (88 cases), 4 grafts was 9.8% (24 cases) and 5 grafts was 0.4% (1 case). The average of grafts was 2.6±0.7 (range: 2 to 5). The proportion of hybrid was 14.3% (35 cases), sequential bypass procedure was 43.0% (105 cases) and multiple artery grafts was 25.4% (62 cases). The perioperative complications of the patients were collected, the patency rate of the grafts was evaluated by coronary angiography or CT within 7 days after the operation, and main adverse cardiovascular and cerebrovascular events (MACCE) were followed up. The survival curve was drawn by Kaplan-Meier method, and the 1-year MACCE rate was calculated by survival analysis. Results: All cases had no transition to thoracotomy and cardiopulmonary bypass procedure, and no cases needed intra aortic balloon pumping and extracorporeal membrane oxygenation during the operation.There were 2 cases of poor incision healing, and reoperation was performed in 10 cases (6 cases of postoperative bleeding, 2 cases of incision debridement, and 2 cases of grafts problems). The rate of MACCE in 30 days was 2.6% (10 cases), which contained 3 cases of death (2 cases of grafts occlusion, 1 case of serious hemorrhage after thoracic puncture drainage), 3 cases of stroke and 5 cases of non-fatal myocardial infarction. By the re-examination of angiography in 7 days after operation, the overall patency of the grafts was 96.1%, and the patency of the left anterior descending was 98.6%. Kaplan-Meier survival analysis was conducted for 235 patients (96.3%) with 1 to 36 months follow-up results, and the 1-year MACCE rate was 5.6% (95%CI: 4.2% to 7.0%) . There was no significant difference among the incidences of MACCE at each stage of learning curve. Surgeon could reduce the operation time and complete more anastomosis with the accumulation of experience after the early 30 cases. Conclusions: MICS-CABG can safely achieve completed revascularization, which has good operative effects in short and medium-long term. There is no significant risk in the early cases of learning curve.

[Clinical study about anatomical and functional reconstruction for frontolateral vertical partial laryngectomy with ultrathin titanium mesh and fascia flap from the strap muscles]

Objective:To investigate the effect of laryngeal reconstruction in functional and anatomical aspect with ultrathin titanium mesh and myofascial flap in patients underwent frontolateral vertical partial laryngectomy with T2 and T3 glottic laryngeal carcinoma. Method:Ten patients with T2 and T3 glottic laryngeal carcinoma underwent frontolateral vertical partial laryngectomy in different range. The ultrathin titanium mesh was shaped up according to the form of thyroid cartilage in operation while the thyroid perichondrium membrane combined with straped myofascial flap was lined under the titanium mesh to restore the laryngeal cavity space. The pronunciation, swallowing capability and extubation rate were observed after surgery. Result:Nine patients underwent extubation within 2 to 4 weeks after surgery, one patients remove metal tube in two-stage after laryngeal dilation surgery with the Montgomery tube. Swallowing and voice function in these patients recovered well and no deglutition disorder was found. CT scan showed that the Titanium meshs were fixed well without displacement and deformity. Electronic laryngoscopy showed that the mucosa of laryngeal lumen was smooth without laryngeal stenosis, keloid contraction, tissue necrosis or titanium mesh exposure. Conclusion:In the cases of T2, T3 glottic laryngeal cancer patients, laryngeal framework reconstruction with the new type of ultrathin titanium mesh, thyroid cartilage membrane and pedicled fascia plap of strap muscles is a good choice after the vertical frontolateral partial laryngectomy. Even some elective T4 cases with the former part invasion in supra-glottic or infra-glottic region can receive this operation. It can reconstruct the physiological and anatomical structure of the larynx, restore laryngeal function with a sound decanulization rate.

[Progress in cohort studies related to injury]

Objective: To summarize the progress of injury cohort studies over the world. Methods: Relevant information of injury cohort publications published before December 2017 were retrieved from PubMed, WanFang and China National Knowledge Infrastructure (CNKI) databases, consisting of the starting year, category of injury, study population, sample size, countries, follow-up duration, main exposure variables, outcome variables and method of data collection, and statistical methods. Results: A total of 295 studies were included in the analysis. The overall number of injury cohort studies increased with a peak in 2000, and then decreased. The top three countries that most frequently published cohort studies were the United States (52), Sweden (46) and the United Kingdom (37). A total of 29 published injury cohorts were identified in China, about 3, 23 and 3 cohort studies from the mainland of China, Taiwan Province, and Hong Kong Specific Administrative Region, respectively. The majority of cohort studies involved a single injury cause (93.6%); the most common injury causes included suicide/self-harm (46.1%), falls (17.3%) and road traffic injuries (14.6%). For the published cohort studies, exposure variables and outcome events varied with injury causes, primarily being collected through data registration system, national survey data, questionnaire survey, telephone interviews, and other means. Conclusion: A number of injury cohorts have been established worldwide, and few in the mainland of China. The existed cohort studies could offer important references for the design of large-scale, multi-center and high-quality injury cohort in China in the future.

[Early clinical outcomes of minimally invasive coronary surgery-total arterial coronary revascularization]

Objective: To summarize the early experience and clinical value of minimally invasive coronary surgery-total arterial coronary revascularization (MICS-TACR) through the left anterior small incision. Methods: Between May 2015 and June 2018, a total of 31 consecutive cases [21 males and 10 females, aged (63.2±9.3) years] in Peking University Third Hospital who were performed MICS-TACR with bilateral internal mammary artery and radial artery were enrolled. Meanwhile, 1 489 cases of conventional median sternal incision off-pump coronary artery bypass grafting (OPCABG) were matched as control group. According to exclusion criteria and matching score, 90 cases [55 males and 35 females, aged (63.8±9.5) years] were selected as the control group, and the perioperative data of the two groups were compared. All patients in MICS-TACR group underwent postoperative angiography and the graft patency was evaluated. Results: There were no statistically significant differences in baseline data between the two groups. The perioperative blood transfusion of MICS-TACR group was less than control group [0(0,0) U vs 0(0,4) U, P=0.003]. There were no statistically significant differences in operative mortality, intraoperative and postoperative intra-aortic balloon pump (IABP) and extracorporeal membrane oxygenation (ECMO) use, re-operation rate, perioperative major adverse cardiac and cerebrovascular events (MACCE), new-onset renal failure, atrial fibrillation, and multiple organ failure between the two groups. Postoperative angiography showed that there was no significant difference in the patency rate between the MICS-TACR group and control group(all P>0.05). Conclusion: Total arterial coronary revascularization can be successfully accomplished under the left anterior small incision, and the early clinical outcome is satisfied.

[The anatomic characteristics and surgical treatment of congenital pyriform sinus fistula]

Objective:To discuss the clinical anatomic characteristics of congenital pyriform sinus fistula and summarize the experiences of open neck surgery. Method：The clinical data of 12 patients with congenital pyriform sinus fistula were retrospectively analyzed.Result:During the operation, all lesions were located below of superior laryngeal nerve. All fistulas were closely related with the supperior part of thyroid gland and laterally passed over the left recurrent laryngeal nerve just before merging into the apex of piriform sinus or beginning of aesophagus. Follow-up periods were ranging between 8 to 65 months. Two months after surgery,one patient showed lateral neck abscess again. After open drainage procedures and antibiotics treatment, there was no recurrence signs during 3 years of follow-up.Conclusion:We found that the congenital pyriform sinus fistula was closely related to the superior thyroid gland and recurrent laryngeal nerve,which was different from the popular theory.We had not encountered types descending into mediastinum and thoracic cavity or ascending along common carotid artery sheath. All fistulas passed over the left recurrent laryngeal nerve，and then merged into the apex of pyriform sinus or beginning of aesophagus.The key point for successful resection of fistulas in block was to remove the superior involvement part of the thyroid gland and exposure the recurrent laryngeal nerve. Based on our practical findings, the neck dissection procedure should not be taken in some patients that the anatomical structure is not clear for repeated infections.

Targeting EZH1 and EZH2 contributes to the suppression of fibrosis-associated genes by miR-214-3p in cardiac myofibroblasts

The role of microRNA-214-3p (miR-214-3p) in cardiac fibrosis was not well illustrated. The present study aimed to investigate the expression and potential target of miR-214-3p in angiotensin II (Ang-II)-induced cardiac fibrosis. MiR-214-3p was markedly decreased in the fibrotic myocardium of a mouse Ang-II infusion model, but was upregulated in Ang-II-treated mouse myofibroblasts. Cardiac fibrosis was shown attenuated in Ang-II-infused mice received tail vein injection of miR-214-3p agomir. Consistently, miR-214-3p inhibited the expression of Col1a1 and Col3a1 in mouse myofibroblasts in vitro. MiR-214-3p could bind the 3'-UTRs of enhancer of zeste homolog 1 (EZH1) and -2, and suppressed EZH1 and -2 expressions at the transcriptional level. Functionally, miR-214-3p mimic, in parallel to EZH1 siRNA and EZH2 siRNA, could enhance peroxisome proliferator-activated receptor-γ (PPAR-γ) expression and inhibited the expression of Col1a1 and Col3a1 in myofibroblasts. In addition, enforced expression of EZH1 and -2, and knockdown of PPAR-γ resulted in the increase of Col1a1 and Col3a1 in myofibroblasts. Moreover, the NF-κB signal pathway was verified to mediate Ang-II-induced miR-214-3p expression in myofibroblasts. Taken together, our results revealed that EZH1 and -2 were novel targets of miR-214-3p, and miR-214-3p might be one potential miRNA for the prevention of cardiac fibrosis.

Targeting myocyte-specific enhancer factor 2D contributes to the suppression of cardiac hypertrophic growth by miR-92b-3p in mice

The role of microRNA-92b-3p (miR-92b-3p) in cardiac hypertrophy was not well illustrated. The present study aimed to investigate the expression and potential target of miR-92b-3p in angiotensin II (Ang-II)-induced mouse cardiac hypertrophy. MiR-92b-3p was markedly decreased in the myocardium of Ang-II-infused mice and of patients with cardiac hypertrophy. However, miR-92b-3p expression was revealed increased in Ang-II-induced neonatal mouse cardiomyocytes. Cardiac hypertrophy was shown attenuated in Ang-II-infused mice received tail vein injection of miR-92b-3p mimic. Moreover, miR-92b-3p inhibited the expression of atrial natriuretic peptide (ANP), skeletal muscle α-actin (ACTA1) and β-myosin heavy chain (MHC) in Ang-II-induced mouse cardiomyocytes in vitro. Myocyte-specific enhancer factor 2D (MEF2D), which was increased in Ang-II-induced mouse hypertrophic myocardium and cardiomyocytes, was identified as a target gene of miR-92b-3p. Functionally, miR-92b-3p mimic, consistent with MEF2D siRNA, inhibited cell size increase and protein expression of ANP, ACTA1 and β-MHC in Ang-II-treated mouse cardiomyocytes. Taken together, we demonstrated that MEF2D is a novel target of miR-92b-3p, and attenuation of miR-92b-3p expression may contribute to the increase of MEF2D in cardiac hypertrophy.

Left ventricular deformation associated with cardiomyocyte Ca(2+) transients delay in early stage of low-dose of STZ and high-fat diet induced type 2 diabetic rats

Background

In the early stage of diabetes, the cardiac ejection fraction is preserved, despite the existence of the subclinical cardiac dysfunction to some extent. However, the detailed phenotype of this dysfunction and the underlying mechanism remain unclear. To improve our understanding of this issue, we used low-dose STZ and high-fat diet to induce type 2 diabetic models in rats. The effects and the mechanism associated with the early stages of the disease were analyzed.

Methods

The type 2 diabetic mellitus (T2DM) in SD rats were induced through 30 mg/kg STZ and high-fat diet. Two-dimensional spackle-tracking echocardiography (STE) and the dobutamine test were performed to examine the cardiac function. Calcium transients of left ventricular myocytes were detected and the related intracellular signalling factors were analyzed by western blotting.

Results

After 6-weeks, T2DM rats in left ventricular (LV) diastole showed decreased global and segment strain(S) levels (P < 0.05), both in the radial and circumferential directions. Strain rate (Sr) abatement occurred in three segments in the radial and circumferential directions (P < 0.05), and the radial global Sr also decreased (P < 0.05). In the systolic LV, radial Sr was reduced, except the segment of the anterior septum, and the Sr of the lateral wall and post septum decreased in the circumferential direction (P < 0.05). Conventional M-mode echocardiography failed to detect significant alterations of cardiac performance between the two groups even after 12 weeks, and the decreased ejection fraction (EF%), fractional shortening (FS%) and end-systolic diameters (ESD) could be detected only under stress conditions induced by dobutamine (P < 0.05). In terms of calcium transients in cardiac myocytes, the T_peak in model rats at 6 weeks was not affected, while the T_decay1/2 was higher than that of the controls (P < 0.05), and both showed a dose-dependent delay after isoproterenol treatment (P < 0.05). Western blot analysis showed that in 6-week T2DM rats, myocardial p-PLB expression was elevated, whereas p-CaMKII, p-AMPK and Sirt1 were significantly down-regulated (P < 0.05).

Conclusion

A rat model of T2DM was established by low dose STZ and a high-fat diet. LV deformation was observed in the early stages of T2DM in association with the delay of Ca²⁺ transients in cardiomyocytes due to the decreased phosphorylation of CaMKII. Myocardial metabolism remodeling might contribute to the early LV function and calcium transportation abnormalities.

Topical application of epidermal growth factor with no scaffold material on the healing of human traumatic tympanic membrane perforations

OBJECTIVE

We evaluated the effects of conservative treatment and topical application of epidermal growth factor (EGF) with no scaffold material on the healing of human traumatic tympanic membrane perforations (TMPs).

STUDY DESIGN

Prospective, randomised clinical trial.

METHODS

A prospective analysis was performed between January 2015 and March 2015 for the treatment of human traumatic TMPs. The closure rate, closure time, hearing gain and rate of purulent otorrhoea were compared between the topical application of EGF and conservative treatment.

RESULT

In total, 97 patients were analysed. The total closure rates did not significantly differ between the observation and EGF groups (83.0% versus 92.0%, P = 0.182). The total average closure time in the observation group was significantly longer than in the EGF group (25.1 ± 10.5 versus 11.7 ± 5.2 days, P = 0.001). When the closure rate was evaluated according to perforation size, no significant difference was seen for medium or large perforations (P = 0.18 and 0.21, respectively). When closure time was evaluated according to perforation size, a significant difference was seen for medium and large perforations (P = 0.001).

CONCLUSIONS

This study suggests that topical application of EGF with no scaffold material may significantly shorten the closure time of human traumatic TMPs. Such a shorter recovery time may lead to reduced healthcare costs. This alternative technique to a classic myringoplasty is particularly beneficial and suitable for the closure of large human traumatic TMPs.

Intravenous superoxide dismutase administration reduces contralateral lung injury induced by unilateral lung ischemia and reperfusion in rats through suppression of activity and protein expression of matrix metalloproteases

BACKGROUND

Ischemia and reperfusion (I/R) of the lungs induces massive superoxide radical production. On the other hand, matrix metalloproteases (MMPs) were shown to play an essential role in I/R-associated lung injury. We aimed to investigate the lung-protective efficacy of intravenous superoxide dismutase (SOD) administration and its relation with MMPs activity in the lungs subsequent to I/R injury.

METHODS

Twenty-two male Sprague-Dawley rats were divided into a sham group (n = 6), a unilateral lung I/R group (n = 8), and a SOD-treated lung I/R group (n = 8). Unilateral lung ischemia was conducted by occluding the left lung hilum for 90 min, followed by 5 hours of reperfusion through release of the occlusion. In the SOD-treated group, SOD was administered intravenously during the first hour of reperfusion. We assessed the protein contents in the broncho-alveolar lavage fluid (PCBAL) as a marker for protein permeability and lung wet-to-dry weight ratio (W/D) for lung water content. We also measured levels of lipid peroxidation and MMP activity in the lungs, by tissue malonedealdehyde (MDA) level with the use of enzyme-linked immunoassay, and the gelatin zymography technique, respectively.

RESULTS

Forty-eight hours of left-lung I/R significantly increased PCBAL (P < .001), W/D (P < .05), tissue MDA level (P < .05), and MMP-9 and MMP-2 activity. SOD treatment attenuated I/R-induced contralateral lung injury, reducing pulmonary permeability, lipid peroxidation, and MMP activities.

CONCLUSIONS

I/R injury of the left lung induced increases in W/D, PCBAL, MDA level, and MMP-9 activity in the right lung. SOD treatment during the first hour of a 5-hour reperfusion protected the lung through suppressing MMP-9 activity and reducing tissue lipid peroxidation.

Attenuation of microRNA-16 derepresses the cyclins D1, D2 and E1 to provoke cardiomyocyte hypertrophy

Cyclins/retinoblastoma protein (pRb) pathway participates in cardiomyocyte hypertrophy. MicroRNAs (miRNAs), the endogenous small non-coding RNAs, were recognized to play significant roles in cardiac hypertrophy. But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy. This study investigates the potential role of microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy. An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC), and in a mouse with transverse aortic constriction (TAC) and in a mouse with subcutaneous injection of phenylephrine (PE) respectively. In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte and based on Ang-II-induced neonatal mouse ventricular cardiomyocyte respectively. We demonstrated that miR-16 expression was markedly decreased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats and mice. Overexpression of miR-16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes, and inhibition of miR-16 induced a hypertrophic phenotype in cardiomyocytes. Expressions of cyclins D1, D2 and E1, and the phosphorylated pRb were increased in hypertrophic myocardium and hypertrophic cardiomyocytes, but could be reversed by enforced expression of miR-16. Cyclins D1, D2 and E1, not pRb, were further validated to be modulated post-transcriptionally by miR-16. In addition, the signal transducer and activator of transcription-3 and c-Myc were activated during myocardial hypertrophy, and inhibitions of them prevented miR-16 attenuation. Therefore, attenuation of miR-16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2 and E1, and activating cyclin/Rb pathway, revealing that miR-16 might be a target to manage cardiac hypertrophy.

Changes in the expression of Fox O1 and death ligand genes during follicular atresia in porcine ovary

Follicular atresia, a key phenomenon in follicle development, eliminates most of the follicles in mammalian ovaries. To investigate the molecular mechanism of follicular atresia in porcine ovaries, we investigated the mRNA expression of three important cell death ligand-receptor systems and Fox O1 in follicles with a diameter of 3-5 mm. The phosphorylation and subcellular localization of Fox O1 during granulosa cell apoptosis was also determined. TRAIL and Fas L played an important role in follicular atresia at this stage. Fox O1 expression was upregulated during atresia, and was confined to the nucleus of granulosa cells; however, phosphorylated Fox O1 was localized to the cytoplasm. These results suggest Fox O1 involvement in the regulation of TRAIL and Fas L expression during follicular atresia in pigs.

Induced bone marrow mesenchymal stem cells improve cardiac performance of infarcted rat hearts

We investigated whether transplantation of bone marrow mesenchymal stem cells (BMSC) with induced BMSC (iBMSC) or uninduced BMSC (uBMSC) into the myocardium could improve the performance of post-infarcted rat hearts. BMSCs were specified by flowcytometry. IBMSCs were cocultured with rat cardiomyocyte before transplantation. Cells were injected into borders of cardiac scar tissue 1 week after experimental infarction. Cardiac performance was evaluated by echocardiography at 1, 2, and 4 weeks after cellular or PBS injection. Langendorff working-heart and histological studies were performed 4 weeks after treatment. Myogenesis was detected by quantitative PCR and immunofluorescence. Echocardiography showed a nearly normal ejection fraction (EF) in iBMSC-treated rats and all sham control rats but a lower EF in all PBS-treated animals. The iBMSC-treated heart, assessed by echocardiography, improved fractional shortening compared with PBS-treated hearts. The coronary flow (CF) was decreased obviously in PBS and uBMSC-treated groups, but recovered in iBMSC-treated heart at 4 weeks (P < 0.01). Immunofluorescent microscopy revealed co-localization of Superparamagnetic iron oxide (SPIO)-labeled transplanted cells with cardiac markers for cardiomyocytes, indicating regeneration of damaged myocardium. These data provide strong evidence that iBMSC implantation is of more potential to improve infarcted cardiac performance than uBMSC treatment. It will open new promising therapeutic opportunities for patients with post-infarction heart failure.

Effect of impaired glucose tolerance on cardiac dysfunction in a rat model of prediabetes

BACKGROUND

The effect of impaired glucose tolerance (IGT) on cardiac function during the chronic prediabetes state is complicated and plays an important role in clinical outcome. However, the molecular mechanisms are not fully understood. This study was designed to observe cardiac dysfunction in prediabetic rats with IGT and to determine whether glucose metabolic abnormalities, inflammation and apoptosis are linked to it.

METHODS

The IGT rat models were induced by streptozocin, and the heart functions were assessed by echocardiography. Myocardial glucose metabolism was analyzed by glycogen periodic acid-Schiff staining, and the pro-apoptotic effect of IGT was evaluated by TUNEL staining. Additionally, caspase-3 activation, macrophage migration inhibitory factor (MIF) and G-protein coupled receptor kinase 2 (GRK2) were detected by Western blotting in cardiac tissue lysates.

RESULTS

Area-under-the-curve of blood glucose in rats injected with streptozotocin was higher than that in controls, increased by 16.28%, 38.60% and 38.61% at 2, 4 and 6 weeks respectively (F = 15.370, P = 0.003). Abnormal cardiac functions and apoptotic cardiomyocytes were observed in the IGT rats, the ejection fraction (EF) being (68.59 ± 6.62)% in IGT rats vs. (81.07 ± 4.59)% in controls (t = 4.020, P = 0.002). There was more glucose which was converted to glycogen in the myocardial tissues of IGT rats, especially in cardiac perivascular tissues. Compared to controls, the cleaved caspase-3, MIF and GRK2 were expressed at higher levels in the myocardial tissues of IGT rats.

CONCLUSIONS

IGT in the prediabetes period resulted in cardiac dysfunction linked to abnormal glycogen storage and apoptosis. Additionally, MIF and GRK2 may be involved in the pathogenesis of cardiac dysfunction in prediabetes and their regulation may contribute to the design of novel diagnostic and therapeutic strategies for those who have potential risks for diabetic cardiovascular complications.

Hyperglycemic myocardial damage is mediated by proinflammatory cytokine: macrophage migration inhibitory factor

Background

Diabetes has been regarded as an inflammatory condition which is associated with left ventricular diastolic dysfunction (LVDD). The purpose of this study was to examine the expression levels of macrophage migration inhibitory factor (MIF) and G protein-coupled receptor kinase 2 (GRK2) in patients with early diabetic cardiomyopathy, and to investigate the mechanisms involved in MIF expression and GRK2 activation.

Methods

83 patients in the age range of 30-64 years with type 2 diabetes and 30 matched healthy men were recruited. Left ventricular diastolic function was evaluated by cardiac Doppler echocardiography. Plasma MIF levels were determined by ELISA. To confirm the clinical observation, we also studied MIF expression in prediabetic rats with impaired glucose tolerance (IGT) and relationship between MIF and GRK2 expression in H9C2 cardiomyoblasts exposed to high glucose.

Results

Compared with healthy subjects, patients with diabetes have significantly increased levels of plasma MIF which was further increased in diabetic patients with Left ventricular diastolic dysfunction (LVDD). The increased plasma MIF levels in diabetic patients correlated with plasma glucose, glycosylated hemoglobin and urine albumin levels. We observed a significant number of TUNEL-positive cells in the myocardium of IGT-rats but not in the control rats. Moreover, we found higher MIF expression in the heart of IGT with cardiac dysfunction compared to that of the controls. In H9C2 cardiomyoblast cells, MIF and GRK2 expression was significantly increased in a glucose concentration-dependant manner. Furthermore, GRK2 expression was abolished by siRNA knockdown of MIF and by the inhibition of CXCR4 in H9C2 cells.

Conclusions

Our findings indicate that hyperglycemia is a causal factor for increased levels of pro-inflammatory cytokine MIF which plays a role in the development of cardiomyopathy occurring in patients with type 2 diabetes. The elevated levels of MIF are associated with cardiac dysfunction in diabetic patients, and the MIF effects are mediated by GRK2.

[Effects of BNP preconditioning on myocardial cell apoptosis and expressions of bcl-2 and Bax during myocardial ischemia-reperfusion injury in rats]

OBJECTIVE

To study the effects of B-type natriuretic peptide (BNP) preconditioning on the apoptosis and expressions of Bcl-2 and Bax in rat cardiomyocytes during myocardial ischemia-reperfusion.

METHODS

Twenty-one male Sprague-Dawley rats weighing (250 ± 50) g were randomly divided into 3 groups of sham operation (SHAM), ischemia-reperfusion (I/R) and B-type natriuretic peptide (BNP). A rat model of in vivo myocardial ischemia-reperfusion injury was established by ligating the left anterior descending coronary artery for 35 minutes and then reperfusing for 240 minutes. The apoptosis of myocardial cell was determined by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end-labeling (TUNEL) method. Real-time polymerase chain reaction and Western blot were used to detect the expression changes of Bcl-2 and Bax in rat ischemia myocardium.

RESULTS

The apoptotic indices of SHAM, BNP and I/R groups were 5.4% ± 4.2%, 22.5% ± 9.5% and 45.2% ± 13.0% respectively (P < 0.05). The Bcl-2 protein expression of SHAM, BNP and I/R groups were 0.87 ± 0.09, 0.70 ± 0.07 and 0.38 ± 0.09 respectively (P < 0.05). The Bax protein expression of SHAM, BNP and I/R groups were 0.08 ± 0.04, 0.39 ± 0.09 and 0.71 ± 0.18 respectively (P < 0.01). The Bcl-2/Bax mRNA ratio of SHAN, BNP and I/R groups were 0.763 ± 0.154, 0.099 ± 0.025 and 0.022 ± 0.024 respectively (P < 0.05).

CONCLUSION

The BNP preconditioning can decrease the myocardial apoptosis induced by ischemia-reperfusion injury. The mechanisms may be associated with an elevated expression of Bcl-2, an increased ratio of Bcl-2/Bax and a lowered expression of Bax.

Pure angular momentum generator using a ring resonator

This paper reports a pure angular momentum generator using a ring resonator surrounded by a group of nano-rods. The evanescent waves of the circulating light in the ring are scattered by the nano-rods and generate a rotating electromagnetic field, which has only angular momentum but no linear momentum along the axis of rotation. The angular order is determined by the difference between the order of Whispering Gallery mode and the number of the rods, the rotating frequency is equal to the light frequency divided by the angular order. The maximum amplitude of the rotating electromagnetic fields can be 10 times higher than the amplitude of the input field when there are 36 rods (R(rod) = 120 nm, nr = 1.6). The pure angular momentum generator provides a new platform for trapping and rotation of small particles.

[Effects of Erigeron breviscapus injection on TNF-alpha, PAI-1 and tPA in rats with acute myocardial infarction]

OBJECTIVE

To research the effects of Erigeron breviscapus injection (EBI) on TNF-alpha, PAI-1 and tPA in rats with acute myocardial infarction.

METHODS

Models of acute myocardial infarction (AMI)were produced by ligation of left anterior descending coronary artery, then rats were randomly divided into control and experimental groups, then respectively gavaged NS, and the low, middle and high dosage of EBI for one week. The cardiac function index and the expression of TNF-alpha, tPA and PAI-1 were measured.

RESULTS

Compared with the NS group, the cardiac function LVEDP, MAP, LVPmax, +/- dp/dt of AMI rat was improved by EBI in all dosage range, and the expression of TNF-alpha and PAI-1, LVEDP were decreased (P < 0.05), the expression of tPA, MAP, LVPmax and +/- dp/dt were increased obviously (P < 0.05) and had a dose-effect relationship.

CONCLUSION

EBI can inhibit the expression of TNF-alpha and PAI-1, increase the expression of tPA,which can prevent the ongoing thrombopoiesis after AMI and improve the cardiac function. This maybe attributes to the inhibition of the overexpression of TNF-alpha.

miR-1/miR-206 regulate Hsp60 expression contributing to glucose-mediated apoptosis in cardiomyocytes

Hsp60 is an important component of defense mechanisms against diabetic myocardial injury; however, the cause of Hsp60 reduction in the diabetic myocardium remains unknown. After stimulation of cardiomyocytes with high glucose in vivo and in vitro, significant up-regulation of miR-1/miR-206 and post-transcriptional modulation of Hsp 60 were observed. Serum response factor (SRF) and the MEK1/2 pathway were involved in miR-1 and miR-206 expression in cardiomyocytes. miR-1 and miR-206 regulated Hsp60 expression post-transcriptionally and accelerated cardiomyocyte apoptosis through Hsp60. These results revealed that miR-1 and miR-206 regulate Hsp60 expression, contributing to high glucose-mediated apoptosis in cardiomyocytes.

Comparison of approaches for efficient gene silencing induced by microRNA-based short hairpin RNA and indicator gene expression

MicroRNA-based short hairpin RNAs (shRNAs) are natural inducers of RNA interference and have been increasingly used in shRNA expression strategies. In the present study, we compared the efficiencies of exogenous green fluorescence protein (GFP) and endogenous glyceraldehyde-3-phosphate dehydrogenase (GAPDH) knockdown and red fluorescent protein (RFP) indicator expression mediated by three differently designed plasmids. RFP was introduced either at the 5' end, at the 3' end of the human mir155-based target gene (TG) (e.g., GFP or GAPDH) shRNA expression cassette (EC), or at the 3' end of the chimeric intron-containing TG shRNA EC. Comparisons with the control vector showed an obvious reduction of GFP or GAPDH expression with the various shRNA expression plasmids (P < 0.05). When RFP was located at the 5' end or at the 3' end of the TG shRNA EC, RFP expression was low; whereas when RFP was connected with the chimeric intron-containing TG shRNA EC, RFP expression was high. Taken together, this study demonstrated an efficient plasmid design for both TG silencing induced by microRNA-based shRNA and indicator gene expression in vitro.

Hypertonic saline ameliorates cerebral edema through downregulation of aquaporin-4 expression in the astrocytes

Osmotherapy with 10% hypertonic saline (HS) alleviates cerebral edema through osmotic force. Aquaporin-4 (AQP4) has been reported to be implicated in the pathogenesis of cerebral edema resulting from a variety of brain injury. This study aimed to determine if 10% hypertonic saline ameliorates cerebral edema through downregulation of AQP4 expression in the perivascular astrocytes in the ischemic cerebral edema. Adult male Sprague-Dawley (SD) rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO) and treated with a continuous i.v. infusion of 10% HS. Brain water content (BWC) analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats was attenuated after 10% HS treatment. This was coupled with the reduction of neuronal apoptosis in the peri-ischemic brain tissue. Concomitantly, downregulated expression of AQP4 in the perivascular astrocytes after 10% HS treatment was observed. Our results suggest that in addition to its osmotic force, 10% HS exerts anti-edema effects possibly through downregulation of AQP4 expression in the perivascular astrocytes. The reduction of brain edema after 10% HS administration can prevent ischemic brain damage.

[Effects of Panax notoginseng saponins on ACE2 and TNF-alpha in rats with post-myocardial infarction-ventricular remodeling]

OBJECTIVE

To research the effects of Panax notoginseng saponins (PNS) on angiotensin-converting enzymes 2 ( ACE2) and tumor necrosis factor-alpha (TNF-alpha) in rats with post-myocardial infarction ventricular remodeling.

METHODS

Models of acute myocardial infarction (AMI) were produced by ligation of left anterior descending coronary artery, 24 hours after operation the rats were randomly divided into control and experiment groups, then respectively administrated with NS, fosinopril and low, middle and high dosage of PNS for four consecutive weeks. To observe effects of PNS on malondialdehyde (MDA), nitric oxide (NO), glutathione peroxidase (GSH-Px), ACE2 and TNF-alpha in rats with post-myocardial infarction ventricular remodeling.

RESULTS

Compared with NS group, MDA significantly decreased, the activity of GSH-Px significantly increased (P < 0.05 or P < 0.01), NO of the high-dose PNS group decreased (P < 0.05), Compared with the NS group, ACE2 increased and TNF-a significantly decreased in low-dose PNS group, middle and high-dose groups (P < 0.05).

CONCLUSION

PNS can stimulate ACE2 to inhibit the expression of TNF-alpha and enhance the antioxidance. PNS can reduce pathological injury of cardiac myocytes in myocardial ischemia and cardiac muscle, which can improve ventricular remodeling.

Light well: a tunable free-electron light source on a chip

The passage of a free-electron beam through a nanohole in a periodically layered metal-dielectric structure creates a new type of tunable, nanoscale radiation source--a "light well". In the reported demonstration, tunable light is generated at an intensity of approximately 200 W/cm(2) as electrons with energies in the 20-40 keV range are injected into gold-silica well structures with a lateral size of just a few hundred nanometers.

Upregulated expression of miR-1/miR-206 in a rat model of myocardial infarction

MicroRNAs (miRNAs) have been increasingly reported to have important roles in diverse biological and pathological processes. We investigated miR-1 and miR-206 expression and their potential roles in a rat model of myocardial infarction (MI). miR-1 and miR-206 expression were significantly increased, and insulin-like growth factor 1 (IGF-1) protein was markedly reduced without obvious change of its mRNA level after MI induction. Position 175-196 of rat IGF-1 3'-untranslated region was identified to be required for efficient downregulation by miR-1/miR-206. IGF-1 level was reduced without changing its transcript level in rat H9C2 myoblast cells modified with miR-1 (H9C2-miR-1). In the serum withdrawal and hypoxic condition, caspase-3 activity and mitochondrial potential were significantly increased in H9C2-miR-1 cells compared with the control group, respectively (p<0.05, p<0.01). Together, our results indicate that miR-1 and miR-206 are involved in apoptotic cell death in MI by post-transcriptional repression of IGF-1.

Andersen-Tawil syndrome: definition of a neurocognitive phenotype

BACKGROUND

The Andersen-Tawil syndrome (ATS) is a potassium ion channelopathy caused by mutations in the KCNJ2 gene. It is characterized by periodic paralysis, cardiac arrhythmias, and distinctive features; the effect of KCNJ2 mutations on the CNS has never been studied.

OBJECTIVE

To define a potential CNS phenotype in ATS using standardized methods.

METHODS

Ten subjects with KCNJ2 mutations and their unaffected siblings were evaluated at the University of California San Francisco General Clinical Research Center. A comprehensive battery of neurocognitive tests was administered to ATS subjects and their unaffected siblings, followed by pairwise analysis of the resultant differences in scores. An EEG was obtained for all ATS subjects.

RESULTS

There was no EEG evidence of subclinical seizure activity in any subject. ATS subjects universally had more school difficulties than their siblings, despite similar IQ between the two groups. On formal neurocognitive testing, there was no difference between ATS subjects and their siblings on tests of verbal and visual memory. Assessment of executive functioning revealed ATS subjects scored 1.93 points lower than their siblings on tests of Design Fluency (95% CI -3.46, 0.01; p = 0.052) and made 1.9 more errors (95% CI 0.46, 2.54; p = 0.005). Subjects with ATS scored an average of 5 points lower than their siblings on tests of matrix reasoning (95% CI -8.67, -1.33; p = 0.008). On tests of general ability, ATS subjects achieved much lower scores than their siblings, with an average difference of 9.13 points for reading (95% CI -12.46, 3.21; p = 0.056) and 23.4 points for mathematics (95% CI -42.53, -4.22; p = 0.017).

CONCLUSION

Mutations in KCNJ2 are associated with a distinct neurocognitive phenotype, characterized by deficits in executive function and abstract reasoning.

Andersen-Tawil syndrome: Prospective cohort analysis and expansion of the phenotype

Andersen-Tawil syndrome (ATS) is an autosomal dominant multisystem disorder characterized by developmental, cardiac, and neuromuscular abnormalities. Approximately 70% of patients have mutations in KCNJ2, resulting in dysfunction of the inward-rectifying potassium channel Kir2.1. Variable expression complicates the diagnosis of ATS, which in many cases, is not made until years after the first recognized symptom. To better define the distinctive clinical features of ATS and facilitate earlier diagnosis, we conducted a prospective, standardized evaluation of 10 subjects with confirmed KCNJ2 mutations. Detailed anthropometric, neurological, and cardiac evaluations were performed. Using this approach, we identified novel skeletal and dental findings and proposed additional diagnostic criteria for ATS dysmorphology.

Correlating phenotype and genotype in the periodic paralyses

BACKGROUND

Periodic paralyses and paramyotonia congenita are rare disorders causing disabling weakness and myotonia. Mutations in sodium, calcium, and potassium channels have been recognized as causing disease.

OBJECTIVE

To analyze the clinical phenotype of patients with and without discernible genotype and to identify other mutations in ion channel genes associated with disease.

METHODS

The authors have reviewed clinical data in patients with a diagnosis of hypokalemic periodic paralysis (56 kindreds, 71 patients), hyperkalemic periodic paralysis (47 kindreds, 99 patients), and paramyotonia congenita (24 kindreds, 56 patients). For those patients without one of the classically known mutations, the authors analyzed the entire coding region of the SCN4A, KCNE3, and KCNJ2 genes and portions of the coding region of the CACNA1S gene in order to identify new mutations.

RESULTS

Mutations were identified in approximately two thirds of kindreds with periodic paralysis or paramyotonia congenita. The authors found differences between the disorders and between those with and without identified mutations in terms of age at onset, frequency of attacks, duration of attacks, fixed proximal weakness, precipitants of attacks, myotonia, electrophysiologic studies, serum potassium levels, muscle biopsy, response to potassium administration, and response to treatment with acetazolamide.

CONCLUSIONS

Hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and paramyotonia congenita may be distinguished based on clinical data. This series of 226 patients (127 kindreds) confirms some clinical features of this disorder with notable exceptions: In this series, patients without mutations had a less typical clinical presentation including an older age at onset, no changes in diet as a precipitant, and absence of vacuolar myopathy on muscle biopsy.

Clinical evaluation of idiopathic paroxysmal kinesigenic dyskinesia: new diagnostic criteria

BACKGROUND

Paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder characterized by short episodes of involuntary movement attacks triggered by sudden voluntary movements. Although a genetic basis is suspected in idiopathic cases, the gene has not been discovered. Establishing strict diagnostic criteria will help genetic studies.

METHODS

The authors reviewed the clinical features of 121 affected individuals, who were referred for genetic study with a presumptive diagnosis of idiopathic PKD.

RESULTS

The majority (79%) of affected subjects had a distinctive homogeneous phenotype. The authors propose the following diagnostic criteria for idiopathic PKD based on this phenotype: identified trigger for the attacks (sudden movements), short duration of attacks (<1 minute), lack of loss of consciousness or pain during attacks, antiepileptic drug responsiveness, exclusion of other organic diseases, and age at onset between 1 and 20 years if there is no family history (age at onset may be applied less stringently in those with family history). In comparing familial and sporadic cases, sporadic cases were more frequently male, and infantile convulsions were more common in the familial kindreds. Females had a higher remission rate than males. An infantile-onset group with a different set of characteristics was identified. A clear kinesigenic trigger was not elicited in all cases, antiepileptic response was not universal, and some infants had attacks while asleep.

CONCLUSIONS

The diagnosis of idiopathic paroxysmal kinesigenic dyskinesia (PKD) can be made based on historical features. The correct diagnosis has implications for treatment and prognosis, and the diagnostic scheme may allow better focus in the search for the PKD gene(s).

Study of the focused laser spots generated by various polarized laser beam conditions

In this work, three-dimensional near-field imaging of the focused laser spot was studied theoretically and experimentally. In the theoretical simulation, we use the electromagnetic equivalent of the vectorial Kirchhoff diffraction integral to calculate the intensity distribution of the focal region, and a high depolarization is found in high numerical aperture systems (NA = 0.85). The experimental set-up is based on a near-field scanning optical microscope (NSOM) system. A high-NA objective lens is used to focus incident light of various polarizations, and a tapered near-field optical fibre probe of the NSOM system is used to determine the intensity of the focal field. The results show an asymmetric distribution of the focused intensity with the linear polarized laser beam.

Implementation of a short-tip tapping-mode tuning fork near-field scanning optical microscope

We present the implementation of a short-tip tapping-mode tuning fork near-field scanning optical microscope. Tapping frequency dependences of the piezoelectric signal amplitudes for a bare tuning fork fixed on the ceramic plate, a short-tip tapping-mode tuning fork scheme and an ordinary tapping-mode tuning fork configuration with an 80-cm optical fibre attached are demonstrated and compared. Our experimental results show that this new short-tip tapping-mode tuning fork scheme provides a stable and high Q factor at the tapping frequency of the tuning fork and will be very helpful when long optical fibre probes have to be used in an experiment. Both collection and excitation modes of short-tip tapping-mode tuning fork near-field scanning optical microscope are applied to study the near-field optical properties of a single-mode telecommunication optical fibre and a green InGaN/GaN multiquantum well light-emitting diode.

Association of ataxin-7 with the proteasome subunit S4 of the 19S regulatory complex

Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disorder characterized by ataxia and selective neuronal cell loss caused by the expansion of a translated CAG repeat encoding a polyglutamine tract in ataxin-7, the SCA7 gene product. To gain insight into ataxin-7 function and to decipher the molecular mechanisms of neurodegeneration in SCA7, a two-hybrid assay was performed to identify ataxin-7 interacting proteins. Herein, we show that ataxin-7 interacts with the ATPase subunit S4 of the proteasomal 19S regulatory complex. The ataxin-7/S4 association is modulated by the length of the polyglutamine tract whereby S4 shows a stronger association with the wild-type allele of ataxin-7. We demonstrate that endogenous ataxin-7 localizes to discrete nuclear foci that also contain additional components of the proteasomal complex. Immunohistochemical analyses suggest alterations either of the distribution or the levels of S4 immunoreactivity in neurons that degenerate in SCA7 brains. Immunoblot analyses demonstrate reduced levels of S4 in SCA7 cerebella without evident alterations in the levels of other proteasome subunits. These results suggest a role for S4 and ubiquitin-mediated proteasomal proteolysis in the molecular pathogenesis of SCA7.

Polyglutamine-expanded ataxin-7 antagonizes CRX function and induces cone-rod dystrophy in a mouse model of SCA7

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder caused by a CAG repeat expansion. To determine the mechanism of neurotoxicity, we produced transgenic mice and observed a cone-rod dystrophy. Nuclear inclusions were present, suggesting that the disease pathway involves the nucleus. When yeast two-hybrid assays indicated that cone-rod homeobox protein (CRX) interacts with ataxin-7, we performed further studies to assess this interaction. We found that ataxin-7 and CRX colocalize and coimmunoprecipitate. We observed that polyglutamine-expanded ataxin-7 can dramatically suppress CRX transactivation. In SCA7 transgenic mice, electrophoretic mobility shift assays indicated reduced CRX binding activity, while RT-PCR analysis detected reductions in CRX-regulated genes. Our results suggest that CRX transcription interference accounts for the retinal degeneration in SCA7 and thus may provide an explanation for how cell-type specificity is achieved in this polyglutamine repeat disease.

Sodium channel inactivation defects are associated with acetazolamide-exacerbated hypokalemic periodic paralysis

A novel mutation in a family with hypokalemic periodic paralysis is described. The mutation R672S is located in the voltage sensor segment S4 of domain II in the SCN4A gene encoding the human skeletal muscle voltage-gated sodium channel. Functional expression of the R672S channels in human embryonic kidney 293 cells revealed a small but significant hyperpolarizing shift in the steady-state fast inactivation, and a dramatic enhancement in channel slow inactivation. These two defects are mainly due to a slow recovery of the mutant channels from fast and/or slow inactivation. Our data may help explain the mechanism underlying hypokalemic periodic paralysis and the patient's worsening from acetazolamide.

A novel gene causing a mendelian audiogenic mouse epilepsy

Frings mice are a model of generalized epilepsy and have seizures in response to loud noises. This phenotype is due to the autosomal recessive inheritance of a single gene on mouse chromosome 13. Here we report the fine genetic and physical mapping of the locus. Sequencing of the region led to identification of a novel gene; mutant mice are homozygous for a single base pair deletion that leads to premature termination of the encoded protein. Interestingly, the mRNA levels of this gene in various tissues are so low that the cDNA has eluded detection by standard library screening approaches. Study of the MASS1 protein will lead to new insights into regulation of neuronal excitability and a new pathway through which dysfunction can lead to epilepsy.

Mutations in Kir2.1 Cause the Developmental and Episodic Electrical Phenotypes of Andersen's Syndrome

Andersen's syndrome is characterized by periodic paralysis, cardiac arrhythmias, and dysmorphic features. We have mapped an Andersen's locus to chromosome 17q23 near the inward rectifying potassium channel gene KCNJ2. A missense mutation in KCNJ2 (encoding D71V) was identified in the linked family. Eight additional mutations were identified in unrelated patients. Expression of two of these mutations in Xenopus oocytes revealed loss of function and a dominant negative effect in Kir2.1 current as assayed by voltage-clamp. We conclude that mutations in Kir2.1 cause Andersen's syndrome. These findings suggest that Kir2.1 plays an important role in developmental signaling in addition to its previously recognized function in controlling cell excitability in skeletal muscle and heart.

Ataxin-7 expression analysis in controls and spinocerebellar ataxia type 7 patients

Expansion of polymorphic CAG repeats encoding polyglutamine cause at least eight inherited neurodegenerative diseases, including Huntington disease and the spinocerebellar ataxias. However, the pathways by which proteins containing expanded polyglutamine tracts cause disease remain unclear. To gain insight into the function of the SCA7 gene product, ataxin-7, as well as its contribution to cell death in spinocerebellar ataxia type 7 (SCA7), polyclonal antibodies were generated and ataxin-7 expression was examined within neuronal tissues from controls and three SCA7 patients. Immunoblotting demonstrates that ataxin-7 is widely expressed but that expression levels vary between tissues. Immunohistochemical analyses indicate that ataxin-7 is expressed within neurons both affected and unaffected in SCA7 pathology and that subcellular localization varies depending upon the neuronal subtype. Additionally, ataxin-7 staining was detected throughout control retina, including intense staining within the cell bodies and photosensitive outer segments of cone photoreceptors. Anti-ataxin-7 antibodies revealed intranuclear inclusions within surviving inferior olivary and cortical pyramidal neurons, as well as within surviving photoreceptor and ganglion cells of SCA7 patients harboring either 42 or 66 CAG repeats at the SCA7 locus. In contrast, inclusion formation was not detected within neurons of a patient with 41 repeats. This study broadens the current understanding of ataxin-7 localization and incorporates for the first time analysis of late-onset SCA7 patients where polyglutamine tract lengths are relatively shorter and disease course less severe than in previously described infantile-onset cases.

An hPer2 phosphorylation site mutation in familial advanced sleep phase syndrome

Familial advanced sleep phase syndrome (FASPS) is an autosomal dominant circadian rhythm variant; affected individuals are "morning larks" with a 4-hour advance of the sleep, temperature, and melatonin rhythms. Here we report localization of the FASPS gene near the telomere of chromosome 2q. A strong candidate gene (hPer2), a human homolog of the period gene in Drosophila, maps to the same locus. Affected individuals have a serine to glycine mutation within the casein kinase Iepsilon (CKIepsilon) binding region of hPER2, which causes hypophosphorylation by CKIepsilon in vitro. Thus, a variant in human sleep behavior can be attributed to a missense mutation in a clock component, hPER2, which alters the circadian period.

Genetic localization of an autosomal dominant leukodystrophy mimicking chronic progressive multiple sclerosis to chromosome 5q31

The hereditary leukodystrophies represent a group of neurological disorders, in which complete or partial dysmyelination occurs in either the central nervous system (CNS) and/or the peripheral nervous system. Adult-onset autosomal dominant leukodystrophy (ADLD) is a slowly progressive, neurological disorder characterized by symmetrical widespread myelin loss in the CNS, and the phenotype is similar to that of chronic progressive multiple sclerosis. We report clinical, neuroradiological and neuropathological data from the originally reported ADLD family. Furthermore, we have localized the gene that causes ADLD to a 4 cM region on chromosome 5q31. Linkage analysis of this family yielded a LOD score of 5.72 at theta = 0.0 with the microsatellite marker D5S804. Genetic localization will lead to cloning and characterization of the ADLD gene and may yield new insights into myelin biology and demyelinating diseases.

Comparison of methods for identifying transcription units and transcription map of the Werner syndrome gene region

To isolate a human disease gene by positional cloning, a critical step is the identification of candidate genes from a targeted genomic region. We used cDNA selection, exon trapping, and genomic sequencing to identify 12 transcription units from a 1.4-Mb genomic region containing the Werner syndrome gene (WRN). This included sequencing of 650 kb in the region of the WRN gene, to date, the most DNA sequenced as part of a positional cloning effort. The result of this combined method was significant overlap among the transcription units identified by each method; yet, no one method identified all of the transcription units. We present here a comparison of the effectiveness and efficiency of these methods and present a transcription map of the Werner syndrome gene region.

A retinoblastoma susceptibility gene product, RB, targeting protease is regulated through the cell cycle

Degradation of cyclin B and cyclin-dependent kinase inhibitor, p27, at a specific time has been shown to play a critical role in regulating the cell cycle. SPase, a nuclear and cytosol protease with cathepsin B- and L-like proteolytic activity, has been identified in several cell lines. This proteolytic enzyme selectively degraded nuclear proteins such as retinoblastoma susceptibility gene product, RB, and transcription factor, SP-1. High levels of SPase activity were detected at the G1/S, moderate levels at the G1 and S phases, and undetectable activity at the M phase of synchronized CV-1 cells, suggesting that SPase activity is regulated through the cell cycle. Degradation of RB correlated with SPase activity throughout the cell cycle, suggesting that SPase regulates RB, which has a functional role in regulating cell cycle. These results demonstrated that SPase plays an integral role in regulating the nuclear regulator, RB, in controlling cell cycle progression.

A unique cathepsin-like protease isolated from CV-1 cells is involved in rapid degradation of retinoblastoma susceptibility gene product, RB, and transcription factor SP1

The regulation of transcription factors by kinase or phosphatase has been well-described. However, little is known about the inactivation of transcription factors or the nuclear regulators by proteolytic degradation. In this report, we purified a specific protease, SPase, from nuclear extracts of the green monkey kidney cell line, CV-1. Studies of biochemical characteristics and substrate specificity indicated that SPase is a cathepsin B-like cysteinyl protease. However, the two tryptic peptide sequences derived from the purified SPase are either identical or highly homologous to those of human cathepsin L, and furthermore, SPase shares immunoreactivity with both anti-human cathepsin L and anti-mouse cathepsin L antibody. The SPase was shown to be localized in both cytoplasm and nucleus when subcellular compartments of CV-1 cells were fractionated. Transcription factor, SP1, and retinoblastoma susceptible gene product, RB, are substrates of SPase while other nuclear factors such as c-Jun and c-Fos are not. These results implied that SPase plays an integral role in regulating a set of proteins in the nuclei. In vivo treatment of CV-1 cells with cysteinyl protease inhibitor, E-64d, protected RB from degradation. SPase failed to degrade underphosphorylated RB present in TPA induced terminally differentiated HL-60 or U937 cells. Phosphorylation of RB may cause conformational changes, thus facilitating proteolytic digestion. These observations suggest that an alternative pathway inactivates the function of RB in controlling cell growth. Therefore, a possible role of SPase may be to affect the stability of important regulators involved in controlling cellular proliferation and differentiation.

Mutations in the consensus helicase domains of the Werner syndrome gene. Werner's Syndrome Collaborative Group

Werner syndrome (WS) is an autosomal recessive disease with a complex phenotype that is suggestive of accelerated aging. WS is caused by mutations in a gene, WRN, that encodes a predicted 1,432-amino-acid protein with homology to DNA and RNA helicases. Previous work identified four WS mutations in the 3' end of the gene, which resulted in predicted truncated protein products of 1,060-1,247 amino acids but did not disrupt the helicase domain region (amino acids 569-859). Here, additional WS subjects were screened for mutations, and the intron-exon structure of the gene was determined. A total of 35 exons were defined, with the coding sequences beginning in the second exon. Five new WS mutations were identified: two nonsense mutations at codons 369 and 889; a mutation at a splice-junction site, resulting in a predicted truncated protein of 760 amino acids; a 1-bp deletion causing a frameshift; and a predicted truncated protein of 391 amino acids. Another deletion is >15 kb of genomic DNA, including exons 19-23; the predicted protein is 1,186 amino acids long. Four of these new mutations either partially disrupt the helicase domain region or result in predicted protein products completely missing the helicase region. These results confirm that mutations in the WRN gene are responsible for WS. Also, the location of the mutations indicates that the presence or absence of the helicase domain does not influence the WS phenotype and suggests that WS is the result of complete loss of function of the WRN gene product.