Melatonin affects the temporal pattern of vocal signatures in birds

In humans and other animals, melatonin is involved in the control of circadian biological rhythms. Here, we show that melatonin affects the temporal pattern of behavioral sequences in a noncircadian manner. The zebra finch (Taeniopygia guttata) song and the crow of the Japanese quail (Coturnix japonica) are courtship vocalizations composed of a stereotyped sequence of syllables. The zebra finch song is learned from conspecifics during infancy, whereas the Japanese quail crow develops normally without auditory input. We recorded and analyzed the complete vocal activity of adult birds of both species kept in social isolation for several weeks. In both species, we observed a shortening of signal duration following the transfer from a light-dark (LD) cycle to constant light (LL), a condition known to abolish melatonin production and to disrupt circadian rhythmicity. This effect was reversible because signal duration increased when the photoperiod was returned to the previous LD schedule. We then tested whether this effect was directly related to melatonin by removal of the pineal gland, which is the main production site of circulating melatonin. A shortening of the song duration was observed following pinealectomy in LD. Likewise, melatonin treatment induced changes in the temporal structure of the song. In a song learning experiment, young pinealectomized finches and young finches raised in LL failed to copy the temporal pattern of their tutor's song. Taken together, these results suggest that melatonin is involved in the control of motor timing of noncircadian behavioral sequences through an evolutionary conserved neuroendocrine pathway.     

Evaluation of retinal and choroidal changes in patients with Alzheimer’s type dementia using optical coherence tomography angiography

AIM: To evaluate the changes in fundus parameters in patients with Alzheimer’s type dementia (ATD) using optical coherence tomography angiography (OCTA), to record flash electroretinograms (ERG) using the RETeval system and to explore changes in retinal function. METHODS: Twenty-nine patients with ATD and 26 age-matched normal subjects were enrolled. All subjects underwent OCTA scans to analyse the superficial retinal vessel parameters in the macular area, including the vessel length density, the vessel perfusion density and the area of foveal avascular zone (FAZ), as well as the choroidal thickness. The differences between the patients with ATD and the normal control group were compared and explored the relevant factors affecting vessel parameters. We also recorded the flash ERGs using the RETeval system and intended to explore changes in retinal function by analysing the ERG image amplitude in patients with ATD. RESULTS: The vessel parameters [Pvessel length density=0.005 and Pvessel perfusion density=0.006) and average choroid thickness (P<0.001) in the macular area of the ATD group was less than the control group. The FAZ area was statistically significantly enlarged in the ATD group (P<0.001). These parameters were correlated with the Mini-Mental State Examination (MMSE) score and the Montreal Cognitive Assessment (MoCA). CONCLUSION: Patients with ATD exhibit decreases in the parameters associated with fundus. In addition, these indicators significantly correlate with the MMSE score and the MoCA score. OCTA may be an adjunct tool with strong potential to track changes in the diagnosis and monitoring the progression of the disease.     

广东省珠海地区不同人群梅毒感染情况分析

目的通过对珠海地区不同人群进行梅毒血清学检测,了解珠海地区不同人群中梅毒的感染情况,为今后加强梅毒的防治工作提供依据。方法采用酶联免疫吸附试验(ELISA)、甲苯胺红不加热血清反应素试验(TRUST),检测珠海地区吸毒人群、性工作者、外来务工人群和无偿献血人群的梅毒感染情况。结果珠海地区吸毒人群、性工作者、外来务工人群、无偿献血人群的梅毒抗体阳性率分别为9.20%、0.98%、0.89%,0.52%;梅毒感染率分别为4.29%、0.65%、0.66%、0.24%,吸毒人群梅毒抗体阳性率及感染率均明显高于其他人群。各人群中,梅毒以隐性感染为主。结论珠海地区在开展性病防治工作时,应对不同人群采取不同措施,加强性健康宣传教育工作,提高人们对梅毒等性病的认知水平,增强自我保护意识,防止梅毒从吸毒者向暗娼或嫖客向家庭成员传播扩散。     

不同频率脉冲电磁场对骨保护素基因敲除小鼠骨代谢指标影响

目的采用不同频率的脉冲电磁场干预骨保护素基因敲除小鼠骨质疏松模型,探讨脉冲电磁 场治疗骨质疏松的最适治疗频率。方法8周龄雌雄各半骨保护素基因敲除小鼠30只,随机分为 A、B、C 3组,每组10只,粤组为空白对照组,不进行干预;B组小鼠每天在强度为4皂栽,频率为8 HZ 的磁场中照射治疗20 min,共30 d;C组小鼠每天在强度为4 mT,频率为32 HZ的磁场中照射治疗20 min,共30凿。各组小鼠在治疗前及治疗30d后用酶联免疫法（ELISA )法检测抗酒石酸酸性磷酸酶 缘遭及血清骨钙素值。结果8HZ、32HZ两治疗组在治疗后抗酒石酸酸性磷酸酶5遭,血清骨钙素含 量与A对照组之间比较差异有统计学意义（P <0.05 ), 8 HZ、32 HZ两治疗组之间治疗前与治疗后所 测三种指标比较差异无统计学意义（P >0.05 )。结论脉冲电磁场对骨保护素基因敲除小鼠骨质疏 松有肯定治疗效果,应用频率为8-32 HZ的磁场治疗能产生相同的治疗效果。     

Role of different negative pressure values in the process of infected wounds treated by vacuum‐assisted closure: an experimental study

Vacuum‐assisted closure (VAC) device is widely used to treat infected wounds in clinical work. Although the effect of VAC with different negative pressure values is well established, whether different negative pressures could result in varying modulation of wound relative cytokines was not clear. We hypothesise that instead of the highest negative pressure value the suitable value for VAC is the one which is the most effective on regulating wound relative cytokines. Infected wounds created on pigs' back were used to investigate the effects of varying negative pressure values of VAC devices. Wounds were treated with VAC of different negative pressure values or moist gauze, which was set as control. The VAC foam, semiocclusive dresses and moist gauze were changed on days 3, 5, 7 and 9 after wounds were created. When changing dressings, tissues from wounds were harvested for bacteria count and histology examination including Masson's trichrome stain and immunohistochemistry for microvessels. Western blot was carried out to test the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Results showed that on days 3 and 5 the number of bacteria in wounds treated by VAC with 75, 150, 225 and 300 mmHg was significantly decreased compared with that in wounds treated by gauze and 0 mmHg pressure value. However, there was no difference in wounds treated with negative pressure values of 75 , 150, 225 and 300 mmHg at any time spot. Immunohistochemistry showed that more microvessels were generated in wounds treated by VAC using 75 and 150 mmHg negative pressure comparing with that using 225 and 300 mmHg on days 3 and 5. However this difference vanished on days 7 and 9. Morphological evaluation by Masson's trichrome staining showed increased collagen deposition in VAC of 75 and 150 mmHg compared with that in VAC of 225 and 300 mmHg. Western blot showed that the expression of VEGF and bFGF significantly increased when the wounds treated with 75 and 150 mmHg negative pressure values compared with the wounds treated with 225 and 300 mmHg on day 5. Treatment using VAC with different negative pressure values more than 75 mmHg has similar efficiency on reducing bacteria in the infected wound. VAC with negative pressure values of 75 and 150 mmHg promote wound healing more quickly than other pressure values. Moreover, comparing with vigorous negative pressure, relatively moderate pressures contribute to wound healing via accelerated granulation growth, increased angiogenic factor production and improved collagen fibre deposition. Further study of this model may show other molecular mechanisms.     

Timing and cell dose determine therapeutic effects of bone marrow stromal cell transplantation in rat model of cerebral infarct

Stereotactic transplantation of bone marrow stromal cells (BMSCs) enables efficient delivery to the infarct brain. This study was aimed to assess its optimal timing and cell dose for ischemic stroke. The BMSCs were harvested from the green fluorescent protein‐transgenic rats and were labeled with quantum dots. The BMSCs (1 × 10⁵ or 1 × 10⁶) were stereotactically transplanted into the ipsilateral striatum of the rats subjected to permanent middle cerebral artery occlusion at 1 or 4 weeks post‐ischemia. Motor function was serially assessed. Using in vivo near infrared (NIR) fluorescence imaging, the engrafted BMSCs were visualized at 3 weeks post‐transplantation. Immunohistochemistry was performed to evaluate their fate. Functional recovery was significantly enhanced when both low and high doses of BMSCs were transplanted at 1 week post‐ischemia, but such therapeutic effects were observed only when the high‐dose BMSCs were transplanted at 4 weeks post‐ischemia. Both optical imaging and immunohistochemistry revealed their better engraftment in the peri‐infarct area when the high‐dose BMSCs were transplanted at 1 or 4 weeks post‐ischemia. These findings strongly suggest the importance of timing and cell dose to yield therapeutic effects of BMSC transplantation for ischemic stroke. Earlier transplantation requires a smaller number of donor cells for beneficial effects.     

南京市不同人群对骨质疏松症知晓情况调查

目的了解南京市一般人群、医护人员和骨质疏松症患者对骨质疏松症相关知识的知晓情况及其影响因素,为制定合理有效的骨质疏松症健康教育策略提供参考依据。方法采用自行设计的问卷对三类人群进行自填式问卷调查。结果医护人员正确认识骨质疏松症的知晓率83.1%,明显高于一般人群的49.1%和患者的44.8%(P=0.000)。关于骨质疏松健康危害的调查选项只有2名医护人员答案完全正确。预防骨质疏松的知识知晓率,医护人员为31.3%,明显高于一般人群10.2%和患者人群7.9%(P=0.000)。调查相关信息的获取和愿意接受的来源中,医护人员主要来自于医疗结构,一般人群和患者人群主要来自媒体机构。结论一般人群和骨质疏松症患者关于骨质疏松症的知识知晓率低,医疗机构在对社会人群的骨质疏松症健康教育中没有发挥应有的作用;而医护人员的骨质疏松症知识也仍然需要加强教育。     

Optimal ICSI timing after the first polar body extrusion in in vitro matured human oocytes

BACKGROUND: This study was conducted to investigate the fertilization and embryo development of human oocytes injected at different time intervals after extrusion of the first polar body (PB) following in vitro maturation (IVM) in IVM cycles. Also, we evaluated whether spindle imaging could serve as a tool to determine the optimal ICSI time. METHODS: Oocytes were collected from 43 women with polycystic ovary syndrome. Metaphase I (MI) oocytes after in vitro culture for 24 h from germinal vesicle stage were subjected to ICSI according to time after first PB extrusion. The intervals were: within 1 h (n=38); 1-2 h (n=30); 2-4 h (n=26);4-6 (n=28) and 6-8 h (n=40). In some MI oocytes, viable spindle location was evaluated using Polscope microscopy at different time intervals after first PB extrusion. RESULTS: Fertilization rate of the MI oocytes injected within 1 h after first PB extrusion was low (15.8; 6/38) (P<0.01 versus all other times). In contrast, the fertilization rate was 80, 92.3, 82.1 and 85% for oocytes injected 1-2, 2-4, 4-6 and 6-8 h after first PB extrusion, respectively. Development of good-quality embryos was not significantly different among all the groups. Interestingly, all the oocytes injected within 1 h after first PB extrusion were in Telophase I. CONCLUSIONS: Human oocytes matured in vitro needed at least 1 h after first PB extrusion to complete nuclear maturation. Use of a live spindle imaging system can help to decide the timing of ICSI for oocytes matured in vitro.     

The effect of using different types of periodic contact rate on the behaviour of infectious diseases: a simulation study

This paper studies the effect of using different types of seasonally varying contact rate on the behaviour of the seasonally varying infectious diseases for an SEIR epidemic model. Our target is to investigate the long term behaviour of the system in response to changes in beta(1), the amplitude parameter of the seasonal contact rate, which is our bifurcation parameter. This amplitude parameter is used as a filter to plot the length in years of the period of the stable endemic periodic solution of the SEIR model. Another main aim of this simulation study is to explain how can the type of the contact rate affect the behaviour of the disease dynamics. The simulation results have indicated that using different functional forms of seasonally varying contact rate generates different patterns of solutions for each disease parameter set and type of contact rate. So prediction of the type of disease outbreaks depends on the form of contact rate. Thus it is important to determine which type of contact rate is more likely to match the actual dynamics of each disease. Also these results have shown how the dynamics of the disease depend on the amplitude of the seasonally varying contact rate. Apart from some of the results for measles with a sinusoidal periodic function the simulation results are original and give a clear and a much broader insight into the features of the dynamics of these diseases [D. Greenhalgh, I.A. Moneim, SIRS epidemic model and simulations using different types of seasonal contact rate, Syst. Anal. Modelling Simul. 43(5) (2003) 573-600; I.A. Moneim, D. Greenhalgh, Threshold and stability results for an SIRS epidemic model with a general periodic vaccination strategy, J. Biol. Syst. 13(2) (2005), to appear].     

Sensory versus motor information in the control of predictive saccade timing

Humans readily make predictive saccades to periodic alternating targets. This predictive behavior depends on internal monitoring of timing error of past saccades in order to determine the time of initiation of future saccades; our earlier studies have confirmed this by finding correlations between latencies of consecutive predictive saccades. It is natural to consider that timing error is determined by visual detection of the difference between the time the target appears and the time the eyes arrive at the target; this in turn implies that saccades must actually be produced in order for their timing errors to be determined and predictive saccade timing to be established. We tested this hypothesis by having subjects view alternating visual targets while fixating a central target in order to eliminate saccade production. After six alternating target presentations, subjects began tracking the alternating targets. Tracking performance was assessed with an error measure that compared saccade latency and inter-saccade interval with desired values (zero and inter-stimulus interval, respectively). Errors in this Prior Viewing paradigm were compared to those from a conventional De Novo paradigm in which saccades began as soon as the alternating targets were presented. Saccades under Prior Viewing reached a low-error steady predictive state more rapidly than under De Novo tracking. The initial saccade under Prior Viewing had a higher latency than the others, suggesting that this saccade was reactive even though the paradigm is predictable; other reasons for this higher latency include time to disengage from the fixation target and time required to pre-program the initial set of saccades. The results show that visual detection of timing error from an actual motor act (saccades) is not necessary to establish predictive saccadic pacing: sensory-only information from viewing the moving targets can help to establish this predictive state.