Principles of calcium signaling. Salisbury Cove, Maine, June 28-30, 2007

A three-day International Symposium entitled "Principles of Calcium Signaling" organized by James N. Weiss, Yale E. Goldman, Stéphane Hatem, Lars Cleemann and Nikolai M. Soldatov in honor of the research contributions of Professor Martin Morad was held at the Mount Desert Island Biological Laboratory, Salisbury Cove, Maine. Support for this meeting was provided in part by GlaxoSmithKline, Leica Microsystems, Nikon Corp., St. Jude Medical, Inc., UCLA Cardiac Arrhythmia Center, Dr. Donald S. Orkand, Bob Hillis Family and OML, and Mount Desert Island Biological Laboratory. The symposium featured sessions on Cardiac physiology, Ion channels and Calcium signaling.     

Stem cells by the shore: Meeting summary of the 2008 MDI Stem Cell Symposium

A diverse group of stem cell biologists converged on the Mount Desert Island Biological Laboratory (MDIBL) on August 8th and 9th, 2008 for the seventh annual Mount Desert Island Stem Cell Symposium co-hosted by the Mount Desert Island Biological Laboratory and the Jackson Laboratory. The focus of this year’s meeting was epigenetics, a timely topic given the remarkable progress in the area of nuclear reprogramming.     

Cell physiology at the Mount Desert Island Biological Laboratory: a brief look back and forward

The Mount Desert Island Biological Laboratory (MDIBL) has played important roles in the development of modern physiological concepts and tools, particularly in the fields of kidney and epithelial cell physiology. Over the last decade, MDIBL has undergone remarkable growth and evolution. This article will briefly review MDIBL's past and outline its future directions. It is hoped that this overview will renew and stimulate interest in MDIBL and, in particular, will encourage an even wider community of physiologists to participate in its ongoing growth and development.     

The refractive significance of the nictitating membrane of the bird eye

Summary Previous authors have suggested that in certain aquatic birds a transparent nictitating membrane of high refractive index could compensate for the refractive loss of the cornea in water. Measurements of refractive indices, refractive state and curvature carried out on a number of aquatic birds indicate that the nictitating membrane does not have a refractive function; the refractive indices of the cornea and nictitating membrane are very similar (approximately 1.37), the nictitating membrane does not alter the refractive state of the eye, and its curvature, when it is in place in front of the globe, is virtually the same as that of the cornea.This research was supported by grants from the National Research Council of Canada and the Canadian National Sportsmen's Fund. The assistance of Mote Marine Laboratory, The Mount Desert Island Biological Laboratory, the Niska Wildlife Foundation and the Felicadades Wildlife Foundation is gratefully acknowledged. The herring gulls and black guillemots were provided by Dr. W.B. Kinter. In addition, the authors are grateful for the assistance provided by Drs. J.L. Lincer and D. Peakall and Mr. R. Orleib.     

Stage-dependency of apoptosis and the blood-testis barrier in the dogfish shark (Squalus acanthias): cadmium-induced changes as assessed by vital fluorescence techniques

Naturally occurring heavy metals and synthetic compounds are potentially harmful for testicular function but evidence linking heavy metal exposure to reduced semen parameters is inconclusive. Elucidation of the exact stage at which the toxicant interferes with spermatogenesis is difficult because the various germ cell stages may have different sensitivities to any given toxicant, germ cell development is influenced by supporting testicular somatic cells and the presence of inter-Sertoli cell tight junctions create a blood-testis barrier, sequestering meiotic and postmeiotic germ cells in a special microenvironment. Sharks such as Squalus acanthias provide a suitable model for studying aspects of vertebrate spermatogenosis because of their unique features: spermatogenesis takes place within spermatocysts and relies mainly on Sertoli cells for somatic cell support; spermatocysts are linearly arranged in a maturational order across the diameter of the elongated testis; spermatocysts containing germ cells at different stages of development are topographically separated, resulting in visible zonation in testicular cross sections. We have used the vital dye acridine orange and a novel fluorescence staining technique to study this model to determine (1) the efficacy of these methods in assays of apoptosis and blood-testis barrier function, (2) the sensitivity of the various spermatogonial generations in Squalus to cadmium (as an illustrative spermatotoxicant) and (3) the way that cadmium might affect more mature spermatogenic stages and other physiological processes in the testis. Our results show that cadmium targets early spermatogenic stages, where it specifically activates a cell death program in susceptible (mature) spermatogonial clones, and negatively affects blood-testis barrier function. Since other parameters are relatively unaffected by cadmium, the effects of this toxicant on apoptosis are presumably process-specific and not attributable to general toxicity.This study was mainly carried out during summer fellowships at the Mount Desert Island Biological Laboratory, Salsbury Cove, Maine, USA, and partly with financial support from the National Research Foundation of South Africa.     

A comparative approach to carbonic anhydrase: the work of Thomas H. Maren

Thomas H. Maren studied carbonic anhydrase (CA) for half a century, venturing into all aspects of this powerful enzyme from active site chemistry to clinical medicine. He was a keen proponent of comparative physiology to illuminate basic principles of the chemistry and biology of CA and spent 47 summers at the Mt. Desert Island Biological Laboratory (MDIBL) studying many non-mammalian species. Following the venerable strategy of selecting the right creature to explore a particular question, Maren derived important insights into the role of CA in ion transport, acid-base regulation and gas exchange. Using the fact that tissue CAs are expressed variably in different species, and that these animals differ in temperature, acid-base status and metabolic rate, he defined the contributions of un-catalyzed and catalyzed CO(2) reactions in many physiological processes. Often this strategy simplified a problem and offered answers not easily obtainable in mammals. As examples, he verified the primary role of HCO(3)(-) as lead ion in CSF formation in fish and extended this to mammals. Using marine fish whose kidneys have very little CA, he uncovered mechanisms of acid-base transfer independent of CA that help to explain why CA inhibition does not lead to total bicarbonate depletion.     

普陀山岛旅游生态安全发展趋势预测

科学地预测海岛目的地旅游生态安全发展趋势,对促进海岛旅游经济和生态环境协调发展具有重要的理论意义和实践价值。基于可持续发展的视角,建立了由承载力-支持力-吸引力-延续力和发展力(CSAED模型)子系统构成的普陀山旅游生态安全指标体系,并在灰色系统GM(1,1)模型和RBF神经网络模型比较选优的基础上,对普陀山岛旅游生态安全发展趋势进行了预测。研究结果表明:(1)和灰色系统GM(1,1)模型相比,RBF神经网络模型的Pearson相关系数和误差均方根值更优,可更精确地拟合普陀山岛旅游生态安全发展趋势;(2)2015—2020年,普陀山岛旅游生态安全指数的RBF神经网络模型预测结果由0.7017增加至0.8135,安全等级由比较安全上升至非常安全。研究结果可为维护普陀山岛旅游生态安全提供决策依据。     

Problems in the institutionalization of tropical biology: the case of the Barro Colorado Island Biological Laboratory

This article examines the changing status of tropical biology by considering the origins and early development of the Barro Colorado Island Biological Laboratory. Today the laboratory is part of a large diversified tropical research center operated by the Smithsonian Institution. However, for most of its history the laboratory led a tenuous existence. Both the early problems and eventual success of the institution can only be explained by considering the interaction of various intellectual, institutional, and broader social factors.     

白血病小鼠模型的建立与应用进展

白血病又被称为"血癌",其发病的根本特征是白血病细胞在骨髓及其他造血组织中呈恶性、无限制地增生,浸润全身各组织和脏器,产生不同症状,使患者易发生严重的感染或继发性的败血症、引起出血、肠功能衰竭、高尿酸血症等,严重威胁到患者的生命。因此白血病治疗的研究至关重要。利用实验动物进行各种疾病、药物疗效实验的研究,是医药领域发展的一个重要方面。对于白血病的研究,小鼠在生物学、遗传学、造血系统等方面与人类相似,因此是较为理想的动物白血病模型。本文对近五年来国内外研究常用的小鼠白血病模型进行综述。     

蛋白质类生物制品几种不合格冻干外观及解决方案

冻干即真空冷冻干燥,是利用升华的原理使物料脱水的一种干燥技术,其广泛用于生物制品,特别是蛋白质类生物制品的生产,以保护生物制品生物活性成分。外观是冻干制品的重要质量属性之一,合格的冻干制品外观应是疏松多孔、色泽均匀、质地细腻的固体。在大规模生产中,由于冻干参数复杂、设备操作的灵活性等因素,冻干制品的饼块有时会出现收缩、裂化、塌陷、雾化、回熔、喷瓶、结膜等不合格外观,从而造成极大的经济损失。现就近年来在蛋白质类生物制品冻干过程中易发生的几种不合格外观及解决方案作一概述。     

肺炎链球菌C多糖含量检测方法的建立

目的使用肺炎链球菌C多糖单克隆抗体(单抗),建立检测荚膜多糖中残留的C多糖含量的方法。方法选择BALB/c雌性小鼠,采用体内诱生单抗腹水,放大生产肺炎链球菌C多糖单抗;使用间接ELISA、抑制性ELISA对其进行特异性鉴定;用特异性和亲和力高的单抗尝试建立肺炎链球菌荚膜多糖中C多糖含量检测的速率比浊法,并对该方法的线性、精密度、特异性进行验证。结果所制4株单抗的抗体类别均为IgM,识别的抗原表位互不相同,亲和力也不同。间接ELISA、抑制性ELISA结果均显示,所获得的单抗能够作用于肺炎链球菌C多糖上的磷酸胆碱位点,具有很好的特异性。选择单抗E8建立速率比浊检测方法的线性、精密度和特异性均良好,检测结果表明肺炎链球菌23个血清型荚膜多糖中C多糖含量不同。结论利用单抗建立了检测肺炎链球菌荚膜多糖中残留的C多糖的含量的速率比浊法。     

两种高危型HPV假病毒的构建及其在血清中和抗体测定中的应用

目的 构建人乳头瘤病毒(human papillomavirus, HPV)16型(HPV16)和18型(HPV18)假病毒,探索优化假病毒制备的条件,并利用制备的假病毒评价HPV疫苗血清抗体的中和活性。方法 将优化后的HPV16和HPV18 L1、L2和EGFP基因片段分别插入pcDNA3.1+载体中,通过多质粒共转染293FT细胞制备假病毒。对转染试剂、多质粒共转染比例、转染时间和细胞裂解时间进行摸索优化,通过测定假病毒的滴度,确定假病毒制备的最佳条件。收获的假病毒用30%的碘克沙醇作为介质进行超速离心纯化,纯化后的假病毒用于电镜观察。利用假病毒中和试验对制备的原核表达复性蛋白HPV16 L1免疫血清以及HPV16和HPV18病毒样颗粒(virus-like particles, VLP)免疫血清进行中和活性评价。结果 成功构建了假病毒,并确定了假病毒制备的最佳条件:pL1∶pL2∶pEGFP等3种质粒共转染比例为1∶0.1∶0.5,总量为4μg;转染时间为72 h,细胞裂解时间为24 h时获得的假病毒滴度最高。透射电镜观察结果显示,HPV16和HPV18假病毒颗粒基本呈规则圆形,形态上与天然病毒颗粒相似。中和试验结果显示,当用原核表达复性蛋白HPV16 L1免疫血清中和HPV16假病毒时,并不能抑制假病毒的感染活性;但HPV16和18 VLP免疫血清能明显的抑制HPV16和HPV18假病毒的感染活性。结论 成功构建并制备了2种高危型HPV假病毒,并可用于中和试验评价HPV疫苗血清抗体的中和活性。     

2017年湖北省襄阳市手足口病患者柯萨奇病毒A2型分离株的突变和重组分析

目的通过对2016-2017年襄阳市手足口病(hand, foot and mouth disease, HFMD)样品的分离与鉴定,了解主要病原之一的柯萨奇病毒A2型(Coxsackievirus, CV-A2)的分子生物学特征。方法收集2016年9月-2017年12月襄阳市HFMD患儿肛拭子样品,用人类横纹肌肉瘤细胞(RD细胞)培养,分离病毒。RT-PCR扩增CV-A2 VP1基因,Megalign软件分析VP1基因同源性,MEGA6软件构建系统发育树。比较3种疾病(急性迟缓性麻痹、手足口病和急性呼吸道感染)CV-A2分离株VP1氨基酸序列,分析可能的致病位点。扩增CV-A2代表株基因组全长序列,用SimPlot软件分析可能的重组事件。结果 2016-2017年CV-A2襄阳株之间VP1核苷酸及氨基酸同源性分别为96.4%~99.8%,98.0%~100.0%;襄阳株与CV-A2原型株(Fleetwood株)之间的核苷酸及氨基酸同源性分别为80.8%~81.9%,95.3%~95.9%。与襄阳株同源性最高的为2017年江西株(GenBank:MG926784),核苷酸及氨基酸同源性分别为96.7%~98.8%,98.0%~98.6%。襄阳市HFMD主要病原之一的CV-A2 VP1基因系统发育树显示,襄阳株与国内主要流行株同属于基因型D。3种疾病分离株的VP1氨基酸比对发现,急性迟缓性麻痹分离株和HFMD分离株在第21、60、82和215位存在差异;而HFMD分离株与呼吸道感染分离株之间只在167位存在差异,由谷氨酸变成天冬氨酸。CV-A2重组分析提示,襄阳株在P1区域与Fleetwood株同属一分支,在P2区域与CV-A5 Swartz株亲缘性最高,但在P3区域与CV-A16 G-10株有较高的相似度。结论虽然CV-A2襄阳株与其他流行株在VP1区序列上亲缘性较高,但其VP1氨基酸突变或与其他肠道病毒的型间重组可能导致其致病特性与流行病学特点发生变化。     

Chloride transport activation by plasma osmolarity during rapid adaptation to high salinity of Fundulus heteroclitus

Transition from low salt water to sea water of the euryhaline fish, Fundulus heteroclitus, involves a rapid signal that induces salt secretion by the gill chloride cells. An increase of 65 mOsm in plasma osmolarity was found during the transition. The isolated, chloridecell-rich opercular epithelium of sea-water-adapted Fundulus exposed to 50 mOsm mannitol on the basolateral side showed a 100% increase in chloride secretion, which was inhibited by bumetanide 10^–4 m and 10^–4 m DPC (N-Phenylanthranilic acid). No effect of these drugs was found on apical side exposure. A Na⁺/H⁺ exchanger, demonstrated by NH₄Cl exposure, was inhibited by amiloride and its analogues and stimulated by IBMX, phorbol esters, and epithelial growth factor (EGF). Inhibition of the Na⁺/H⁺ exchanger blocks the chloride secretion increase due to basolateral hypertonicity. A Cl^–/HCO ₃ ^– exchanger was also found in the chloride cells, inhibited by 10^–4 m DIDS but not involved in the hyperosmotic response. Ca²⁺ concentration in the medium was critical for the stimulation of Cl^– secretion to occur. Chloride cell volume shrinks in response to hypertonicity of the basolateral side in sea-water-adapted operculi; no effect was found on the apical side. Freshwater-adapted fish chloride cells show increased water permeability of the apical side. It is concluded that the rapid signal for adaptation to higher salinities is an increased tonicity of the plasma that induces chloride cell shrinkage, increased chloride secretion with activation of the Na⁺K⁺2Cl^– cotransporter, the Na⁺/H⁺ exchanger and opening of Cl^– channels.The work was supported by the National Institutes of Health, Research Grant EYO1340 to J.A.Z. Part of this research was performed while Dr. Zadunaisky was a Scholar In Residence at the Fogarty International Center of The National Institutes of Health in Bethesda, Maryland. Ms. Dawn Roberts was a fellow of the Grass Foundation and Pew Foundation during this work. Grants from the National Science Foundation and the National Institutes of Health to the Mount Desert Island Biological Laboratory also provided assistance for this research.     

History of American Marine Biology and Marine Biology Institutions Introduction: Origins of American Marine Biology

SYNOPSIS.In the 1840s and 1850s professional naturalists dredgedshallow sea-water on the eastern coast of the United Statesto obtain marine specimens for teaching and research. In 1871Spencer F. Baird, first U.S. Commissioner of Fish and Fisheries,organized amarine biological laboratory at Woods Hole, Massachusetts,for basic biological research as well as for practical fisherybiology. In 1873 Louis Agassiz established his summer marinestation for teachers on Penikese Island, which stimulated others,especially some of his former students, to do likewise alongthe eastern coast in subsequent years, culminating in the renownedMarine Biological Laboratory at Woods Hole (1888). On the Pacificcoast the pioneer marine laboratories were the Hopkins MarineLaboratory (1892) and the prestigious Scripps Institute of Oceanographyin California (1903), and the Puget Sound Biological Station,later known as the Friday Harbor Laboratories, in Washington(1903). Today, over 50 marine laboratories are in operationin the 21 contiguous coastal states for education and researchin marine biology     

The occurrence of urediniospores of Cronartium ribicola within the petiole of Ribes petiolare

Urediniospores ofCronartium ribicola J. C. Fisch. exRabenh. were observed within the petiole ofRibes petiolare L. These spores occurred internal to xylem tissues within the region of undifferentiated parenchyma cells (pith). Fungal tissues were sparse and fully differentiated sori were absent.Research Plant Pathologist and Biological Laboratory Technician, USDA Forest Serv., Intermountain Forest and Range Exp. Sta., Ogden, Utah, stationed in Moscow, Idaho83843, at Forestry Sciences Laboratory, maintained in cooperation with the University of Idaho.     

<Emphasis Type="Italic">Lobelia proctorii</Emphasis> sp. nov. (Lobelioideae,Campanulaceae/Lobeliaceae) from the Philippines

A new Lobelia species is described from Mount Guiting Guiting, an ultramafic mountain on Sibuyan Island in the Philippines.     

Multivariate analysis of periphytic and benthic diatom assemblages from Papua New Guinea

The benthic and periphytic diatom flora is studied in 136 fresh waters in Papua New Guinea. DCA ordination and TWINSPAN are used to describe 20 diatom assemblages. Conductivity, water temperature and altitude are the main sources for the variation in the data. Laing Island Biological Station publication n° 214 Laing Island Biological Station publication n° 214     

Species of reptiles occupying habitat islands in Western Arizona: a deterministic assemblage

Summary Island size, habitat heterogeneity, and distance from major (mainland) stands of habitat were examined relative to composition and number of coexisting reptile species dependent on upland habitats of 11 mountain and 4 riparian habitat islands. Species richness increased with area on mountain islands, but area was unimportant in predicting species richness on riparian islands. Instead, isolation was of primary importance. Regardless of factors determining species richness, composition of species were deterministic; small assemblages were always totally included subsets of all larger assemblages. This pattern of determinism apparently reflects selective extinctions and the inability of species to recolonize due to the insurmountable barrier imposed by the Sonoran Desert.     

Preliminary Report on the Anurans of Mount Hilong-hilong,Agusan Del Norte,Eastern Mindanao,Philippines

Mount Hilong-hilong is a key biodiversity area, spanning several municipalities in the provinces of the Caraga Region(Agusan del Norte, Agusan del Sur, Surigao del Norte and Surigao del Sur), northeastern Mindanao Island, southern Philippines. The Hilong-hilong massif remains one of the most significant forested areas in Mindanao, threatened with habitat modification(forest removal, degradation) and other anthropogenic disturbances related to renewable resource extraction. Amphibians are key indicator species for environmental quality and are useful focal taxa for conservation efforts. Relying on historical museum database information and new survey work on Mount Hilonghilong, we provide species accounts and describe microhabitat preferences of the anurans(frogs and toads) present in the area. Twenty-seven species representing seven anuran families were studied in detail at elevations between 700 to 1300 meters above sea level; 16 of these species are Mindanao faunal region endemics. Qualitative overlap in microhabitat use was observed, suggesting that, for the species recorded, intact forest may ensure species persistence to some levels of anthropogenic disturbance. A more extensive herpetofaunal survey is needed to fully estimate the herpetofaunal diversity of Mount Hilong-hilong. Because amphibians represent fine-scale indicators of environmental quality and microendemism, we recommend appropriate fine-scaled regional strategies geared towards the conservation of amphibians in the Caraga area, northeast Mindanao Island.