Integrative taxonomy of the Russet Bush Warbler Locustella mandelli complex reveals a new species from central China

Background: The Russet Bush Warbler Locustella(previously Bradypterus) mandelli complex occurs in mountains in the eastern Himalayas, southern China, Vietnam, the Philippines, and Indonesia. The taxonomy has been debated,with one(L. seebohmi) to four(L. seebohmi, L. mandelli, L. montis and L. timorensis) species having been recognised.Methods: We used an integrative approach, incorporating analyses of morphology, vocalizations and a molecular marker, to re-evaluate species limits in the L. mandelli complex.Results: We found that central Chinese L. mandelli differed from those from India through northern Southeast Asia to southeast China in plumage, morphometrics and song. All were easily classified by song, and(wing + culmen)/tail ratio overlapped only marginally. Both groups were reciprocally monophyletic in a mitochondrial cytochrome b(cytb) gene tree, with a mean divergence of 1.0 ± 0.2%. They were sympatric and mostly altitudinally segregated in the breeding season in southern Sichuan province. We found that the Mt Victoria(western Myanmar) population differed vocally from other L. mandelli, but no specimens are available. Taiwan Bush Warbler L. alishanensis was sister to the L. mandelli complex, with the most divergent song. Plumage, vocal and cytb evidence supported the distinctness of the south Vietnamese L. mandelli idonea. The Timor Bush Warbler L. timorensis, Javan Bush Warbler L.montis and Benguet Bush Warbler L. seebohmi differed distinctly in plumage, but among-population song variation in L. montis exceeded the differences between some populations of these taxa, and mean pairwise cytb divergences were only 0.5–0.9%. We also found that some L. montis populations differed morphologically.Conclusions: We conclude that the central Chinese population of Russet Bush Warbler represents a new species,which we describe herein, breeding at mid elevations in Sichuan, Shaanxi, Hubei, Hunan and Guizhou provinces.The taxonomic status of the other allopatric populations is less clear. However, as they differ to a degree comparable with that of the sympatric L. mandelli and the new species, we elevate L. idonea to species status, and retain L. seebohmi and L. montis as separate species, the latter with timorensis as a subspecies. Further research should focus on different populations of L. montis and the Mt Victoria population of L. mandelli.     

Why cuckoos should parasitize parrotbills by laying eggs randomly rather than laying eggs matching the egg appearance of parrotbill hosts?

The coevolutionary interaction between cuckoos and their hosts has been studied for a long time, but to date some puzzles still remain unsolved. Whether cuckoos parasitize their hosts by laying eggs randomly or matching the egg morphs of their hosts is one of the mysteries of the cuckoo problem. Scientists tend to believe that cuckoos lay eggs matching the appearance of host eggs due to selection caused by the ability of the hosts to recognize their own eggs.In this paper, we first review previous empirical studies to test this mystery and found no studies have provided direct evidence of cuckoos choosing to parasitize host nests where egg color and pattern match. We then present examples of unmatched cuckoo eggs in host nests and key life history traits of cuckoos, e.g. secretive behavior and rapid egg-laying and link them to cuckoo egg laying behavior. Finally we develop a conceptual model to demonstrate the egg laying behaviour of cuckoos and propose an empirical test that can provide direct evidence of the egg-laying properties of female cuckoos. We speculate that the degree of egg matching between cuckoo eggs and those of the host as detected by humans is caused by the ability of the hosts to recognize their own eggs, rather than the selection of matching host eggs by cuckoos. The case of Common Cuckoos(Cuculus canorus) and their parrotbill hosts(Paradoxornis alphonsianus), where it has been shown that both have evolved polymorphic eggs(mainly blue and white), was used to develop a conceptual model to demonstrate why cuckoos should utilize parrotbill hosts by laying eggs randomly rather than laying eggs matching the appearance of host eggs.In conclusion, we found no evidence for the hypothesis that cuckoos lay eggs based on own egg color matching that of the parrotbill-cuckoo system. We argue theoretically that laying eggs matching those of the hosts in this system violates a key trait of the life history of cuckoos and therefore should be maladaptive.     

Molecular biology and its applications in orthodontics and oral and maxillofacial surgery

Molecular biology is an exciting, rapidly expanding field, which has enabled enormously greater understanding of the biology of diseases and malfunctions in many fields. It chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA and protein synthesis and how these interactions are regulated. Since the introduction of molecular biology into modern science, numerous other fields have been enabled to go ““molecular““. Advanced molecular biological techniques showed us new avenue towards finding answers to the questions asked for decades. The first part of this article described the history of molecular biology. It started as a joined discipline of other areas of biology, i.e. genetics and biochemistry in the 1930s and 1940s, and enjoyed its classical period and became institutionalized in the 1950s and 1960s. Major molecular techniques manipulating proteins, DNA and RNA were introduced and their mechanisms were concisely illustrated. The current knowledge of molecular biology and their applications in orthodontic and oral and maxillofacial surgery, i.e. osteoclast differentiation and function, regulation of tooth movement, mechanotransduction/cell-signalling, bone fracture healing, oral cancer as well as craniofacial/dental anomalies and distraction osteogenesis were discussed. Although the problems of introducing molecular technologies are still substantial, it is anticipated that the future of medicine/dentistry will be ““molecular““: molecular prevention, molecular diagnosis and molecular therapy.     

Bird guild loss and its determinants on subtropical land-bridge islands,China

Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.     

摘要《ANKYLOS~号种植体周围软组织的组织学分析的动物实验研究》

Purpose&Aim:The importance of the soft tissue-implant interface is enhanced by the presence of a micro-gap between the implant and the abutment,which represents a contamination site for bacteria.The aim of this study was to investigate the interface between the ANKYLOS gap-free implant system and the surrounding soft tissues in a dog model.原因与目的:种植体与修复基台的连接处存在着微隙,构成细菌的污染区域,这一特点使得软组织一种植体界面的重要性更加被重视     

Recurrent ameloblastoma in the anterior skull base： Report of 3 cases

Ameloblastoma is a benign but locally invasiveepithelial odontogenic tumor. Recurrence ofameloblastoma is most common after inadequate treat-ment, with an incidence up to 90% in the mandibleand 100% in the maxilla[1]. Despite radical resectionsincluding adjacent soft tissues, a recurrence rate of5% to 15% has been reported[2]. However, only a fewcases of recurrence reported in the literature involvedthe temporal fossa [3～5]. We presented 3 patients withrecurrent ameloblastoma in the anterior …     

重视和加强对口腔遗传性疾病的研究

There are many kinds of oral hereditary diseases. Although some attempts have been tried to find the genetics of those diseases,still fewer information are available than the other hereditary diseases at present. Much is needed to do in the future. This article reviewed some cutting-edge findings on the genetics of several oral hereditary diseases,including hereditary diseases involving the teeth, periodontal tissues, soft and hard tissues of the oral and maxillofacial region, as well as cleft lip and palate.     

Intracystic negative pressure may promote bone formation around jaw cysts

The growth and enlargement of jaw cysts are associated with raised intracystic pressure and bone resorption surrounding the cysts.The major bone-resorbing cells are the osteoclasts.They are acting under the influence of local bone-resorbing factors: prostaglandins,proteinases and cytokines.It was found that positive pressure enhanced the expression of IL-1αmRNA and protein in epithelial cells of odontogenic keratocyst,and increased the secretion of matrix metalloproteinase and PGE2 in a co-culture of odontogenic keratocyst fibroblasts and epithelial cells.However,the signal intensities for IL-1α mRNA and protein in the epithelium were significantly decreased after marsupialization which relived intracystic pressure.Experimental study indicated that intermittent negative pressure could promote osteogenesis in human bone marrow-derived stroma cells(BMSCs) in vitro.We propose a hypothesis that bone formation around the cyst of the jaws would be stimulated by intracystic negative pressure.     

Tolerance of disturbance by humans in long-time resident and recent colonist urban doves

Background: A critical trait for successful urban dwelling by birds is the ability to tolerate high levels of disturbing stimulation by humans. If such tolerance is partly acquired gradually after colonization, species with a long history of residence in cities are likely to be more tolerant of such stimulation than recent urban colonists, but this has not often been tested.Methods: We tested whether introduced Rock(Columba livia) and Spotted(Streptopelis chinensis) Doves, historically long-term residents of Melbourne, Australia, were more tolerant of disturbance by humans than the very recent colonist, the native Crested Pigeon(Ochyphaps lophotes) by comparing the Flight Initiation Distances(FID) and time allocations to vigilance during foraging of all three species in urban Melbourne. That all three species are members of the Columbiformes reduces the possibility that any species differences in tolerance are simply phylogenetic in origin.Results: Flight initiation distance was shorter in Rock Doves than in the other two species, which did not differ in approachability by a human. Rock Doves retreated from an approaching human mainly by walking a relatively short distance, Crested Pigeons mainly by running a relatively short distance and Spotted Doves primarily by flying a comparatively long distance. The time allocation to anti-predator vigilance of Rock Doves was smaller than that of the other two species, whose allocations were similar.Conclusions: The very recent colonist of eastern Melbourne, the Crested Pigeon, was not the least tolerant of disturbance by humans of the three related species. Natural selection for tolerance therefore probably cannot entirely explain the pattern of tolerance evident among these urban dove species and behavioural flexibility is probably involved. Length of residency in a city is not an infallible guide to a species’ level of tolerance of disturbance by humans.     

Dlx2 over-expression: a possible mechanism for first branchial arch malformation

The first branchial arch malformation(FBAM) is a rare congenital defect associated with anomalous development of the first and second branchial arches.Cause of FBAM still remains unknown,and is thought in most cases to be multifactorial,involving both genetic and enviromental factors.Dlx2 as a member of the Dlx homeobox gene family,plays a crucial role in the development of the first branchial arch.The tissues regulated mainly by Dlx2 are coincident with the tissues mainly involved in FBAM.Dlx2 over-expression generated by electroporation transfection can disturb the migration and differentiation of cranial neural crest cells(CNCCs),which migrate to the branchial arches and in turn give rise to much of the facial skeleton and connective tissues.Furthermore,Dlx2 over-expression can be found in the first branchial arch spontaneous mutant mice.So we hypothesize that Dlx2 over-expression mutation causes FBAM due to an increase in cell-cell adhesion and inhibiting the migration of CNCC to the first branchial arch in the early stage,or migrating to an incorrect position and can’t differentiate into normal tissues.What an exact role of Dlx2 over-expression in FBAM remains to be investigated and Dlx2 over-expression transgenic mouse will be a nice model for further research in FBAM.     

Cytotoxicity and arecoline mechanisms in human gingival fibroblasts in vitro

Betel nut chewing, like cigarette smoking, is a popular oral habit which impinges on the daily lives of a population of approximately 200 million. People who chew betel nuts have a higher prevalence of periodontal diseases than those who do not. Many of the undesirable effects of betel nuts have been attributed to arecoline, a major component of the particular alkaloid in betel nuts. In this in vitro study, we have focused on the effects of arecoline and the role it could play in periodontal breakdown via its direct effects on human gingival fibroblasts. Human gingival fibroblasts were derived from three healthy individuals undergoing crown-lengthening procedures. We found that arecoline is cytotoxic to human gingival fibroblasts at a concentration higher than 50 μg/ml by depleting intracellular thiols and inhibiting mitochondrial activity (P<0.05). In addition, the cells displayed a marked arrest at G₂/M phase in a dose-dependent manner. Repeated and long-term exposure to arecoline could impair the gingival fibroblast functions. As they are cytotoxic, the use of betel nut products in conjunction with periodontal therapy may interfere with optimal healing and/or lead to further periodontal breakdown. Received: 16 February 2000 / Accepted: 25 July 2000     

DENTAL IMPLANTS IN COMPLICATED EDENTULOUS PATIENTS

Dental implants have shown to increase retention and stability of dentures in the rehabilitation of edentulouspatients and still it remains one of the most complex restorative challenges due to a number of variables that affectthe esthetic and functional aspect of the prosthesis.Implant-retained prostheses must compensate forinsufficiencies while allowing the restoration of the white and the red esthetics and satisfying patient demands.     

Methods and studies of tongue reconstruction

Total and even partial glossectomy could be a major event in the life of a patient. Tongue function is so complicated which makes maintaining normal functions of the tongue such as swallowing and speech and preserving larynx integrity after the surgery is a primary objective of the surgeon. This task is very difficult and the result is not predictable. Recent years, however, there has been interesting developments in microsurgical techniques, and these advancements enable oral and maxillofacial surgeons to achieve better results and improve the quality of their patient′s life. The results even with use of the new technology are still far from perfect. Several reasons may cause variation in the result. Some of them have to do with the patient such as general health and other reasons are due to the method that is used and nature of the defect after the removal of the tumor. This article was undertaken to summarize the various methods and techniques used over the years to restore oral tongue functions after defects.     

Diagnosis and management of venous malformations: An overview

Venous malformations pose some of the most difficult challenges in the practice of medicine today. Clinical manifestations of these lesions are extremely protean. Because of the rarity of these lesions, most clinicians have limited experience in their diagnosis and management, which augments the enormity of the problem and can lead to misdiagnoses, inadequate treatment, high complication rates, and poor patient outcomes. Vascular malformations are best treated in medical centers where patients with these maladies are seen regularly and the team approach is used. The occasional embolizer will never gain enough experience to treat these problematic lesions adequately. More importantly, when complications do occur, the morbidity of that complication is worsened because of this lack of experience and the absence of an experienced team of physicians. All too frequently, the patient ultimately pays for a physician＇ s initial enthusiasm, inexperience, folly, and lack of necessary clinician backup. A cavalier approach to the management of venous malformations will always lead to significant complications and dismal patient outcomes. These patients should be referred to centers that regularly treat vascular malformations, appropriately manage complications in a timely manner, and routinely deal with the dilemmas they present. Only in this fashion can significant experience be gained, improved judgment in managing these lesions develop, and definitive appropriate statements in the treatment of vascular anomalies evolve.     

Brain size and urbanization in birds

Background: Brain size may affect the probability of invasion of urban habitats if a relatively larger brain entails superior ability to adapt to novel environments. However, once urbanized urban environments may provide poor quality food that has negative consequences for normal brain development resulting in an excess of individuals with small brains.Methods: Here we analyze the independent effects of mean, standard deviation and skewness in brain mass for invasion of urban habitats by 108 species of birds using phylogenetic multiple regression analyses weighted by sample size.Results: There was no significant difference in mean brain mass between urbanized and non-urbanized species or between urban and rural populations of the same species, and mean brain mass was not significantly correlated with time since urbanization. Bird species that became urbanized had a greater standard deviation in brain mass than non-urbanized species, and the standard deviation in brain mass increased with time since urbanization. Brain mass was significantly left skewed in species that remained rural, while there was no significant skew in urbanized species. The degree of left skew was greater in urban than in rural populations of the same species, and successfully urbanized species decreased the degree of left skew with time since urbanization. This is consistent with the hypothesis that sub-optimal brain development was more common in rural habitats resulting in disproportionately many individuals with very smal brains.Conclusions: These findings do not support the hypothesis that large brains promote urbanization, but suggest that skewness has played a role in the initial invasion of urban habitats, and that variance and skew in brain mass have increased as species have become urbanized.     

Restoring and replacing teeth in the aesthetic zone

Today with the continual advancement in all aspects of dentistry, the focus on aesthetic outcome has intensi-fied. It is true that with better knowledge and understanding in aesthetic treatment planning and smile analysis,we are now in a better position to address our patient's aesthetic and functional concerns. However, if old orconventional materials were used to treat these highly demanding patients, we are still not able to satisfy them ad-equately. It is with the combination of good diagnostic and treatment planning skills coupled with excellent mate-rial choices that gives us a better chance for success.     

侵袭性牙周炎患者外周血CD-4+CD-25+调节性T细胞的检测及功能分析

Objective To investigate the changes of proportion and suppression function of CD-4+ CD-25+ regulatory T cells in the peripheral blood of patients with aggressive periodontitis.Methods Flow cytometric analysis was used to detect the frequency of CD-4+ CD-25+ regulatory T cells in the peripheral blood of 16 patients with generalized aggressive periodontitis and 17 patients with chronic periodontitis,as well as 17 periodontal healthy controls.Furthermore,CD-4+ CD-25+ regulatory T cells and CD-4+ CD-25- T cells were separated from peripheral blood of each enrolling subject using magnetic cell sorting technology.The direct suppression effect of CD-4+ CD-25+ regulatory T cells on CD-4+ CD-25- T lymphocytes proliferation was performed by the mixed lymphocytes reaction and measured by 3H-thymidine radioactive assay.Results The patients with generalized aggressive periodontitis had a lower frequency of CD-4+ CD-25+ regulatory T cells(9.71±4.01)%in the peripheral blood than periodontal healthy controls [(14.72±3.51)%]and chronic periodontitis patients[(17.01±5.16 )%],P＜0.05.A significant decrease was found in the suppression function of CD-4+ CD-25+ regulatory T cells from peripheral blood of patients with generalized aggressive periodontitis when co-cultured with CD-4+ CD-25- T lymphocytes in the proportion of 2:1,1:1 and 1:2 as compared with chronic periodontitis patients and periodontal healthy controls(P＜0.05).Conclusions Diminished numbers and decreased suppression function of CD-4+ CD-25+ regulatory T cells were found in patients with generalized aggressive periodontitis.     

侵袭性牙周炎患者外周血CD-4+CD-25+调节性T细胞的检测及功能分析

Objective To investigate the changes of proportion and suppression function of CD-4+ CD-25+ regulatory T cells in the peripheral blood of patients with aggressive periodontitis.Methods Flow cytometric analysis was used to detect the frequency of CD-4+ CD-25+ regulatory T cells in the peripheral blood of 16 patients with generalized aggressive periodontitis and 17 patients with chronic periodontitis,as well as 17 periodontal healthy controls.Furthermore,CD-4+ CD-25+ regulatory T cells and CD-4+ CD-25- T cells were separated from peripheral blood of each enrolling subject using magnetic cell sorting technology.The direct suppression effect of CD-4+ CD-25+ regulatory T cells on CD-4+ CD-25- T lymphocytes proliferation was performed by the mixed lymphocytes reaction and measured by 3H-thymidine radioactive assay.Results The patients with generalized aggressive periodontitis had a lower frequency of CD-4+ CD-25+ regulatory T cells(9.71±4.01)%in the peripheral blood than periodontal healthy controls [(14.72±3.51)%]and chronic periodontitis patients[(17.01±5.16 )%],P＜0.05.A significant decrease was found in the suppression function of CD-4+ CD-25+ regulatory T cells from peripheral blood of patients with generalized aggressive periodontitis when co-cultured with CD-4+ CD-25- T lymphocytes in the proportion of 2:1,1:1 and 1:2 as compared with chronic periodontitis patients and periodontal healthy controls(P＜0.05).Conclusions Diminished numbers and decreased suppression function of CD-4+ CD-25+ regulatory T cells were found in patients with generalized aggressive periodontitis.     

侵袭性牙周炎患者外周血CD-4+CD-25+调节性T细胞的检测及功能分析

Objective To investigate the changes of proportion and suppression function of CD-4+ CD-25+ regulatory T cells in the peripheral blood of patients with aggressive periodontitis.Methods Flow cytometric analysis was used to detect the frequency of CD-4+ CD-25+ regulatory T cells in the peripheral blood of 16 patients with generalized aggressive periodontitis and 17 patients with chronic periodontitis,as well as 17 periodontal healthy controls.Furthermore,CD-4+ CD-25+ regulatory T cells and CD-4+ CD-25- T cells were separated from peripheral blood of each enrolling subject using magnetic cell sorting technology.The direct suppression effect of CD-4+ CD-25+ regulatory T cells on CD-4+ CD-25- T lymphocytes proliferation was performed by the mixed lymphocytes reaction and measured by 3H-thymidine radioactive assay.Results The patients with generalized aggressive periodontitis had a lower frequency of CD-4+ CD-25+ regulatory T cells(9.71±4.01)%in the peripheral blood than periodontal healthy controls [(14.72±3.51)%]and chronic periodontitis patients[(17.01±5.16 )%],P＜0.05.A significant decrease was found in the suppression function of CD-4+ CD-25+ regulatory T cells from peripheral blood of patients with generalized aggressive periodontitis when co-cultured with CD-4+ CD-25- T lymphocytes in the proportion of 2:1,1:1 and 1:2 as compared with chronic periodontitis patients and periodontal healthy controls(P＜0.05).Conclusions Diminished numbers and decreased suppression function of CD-4+ CD-25+ regulatory T cells were found in patients with generalized aggressive periodontitis.     

侵袭性牙周炎患者外周血CD-4+CD-25+调节性T细胞的检测及功能分析

Objective To investigate the changes of proportion and suppression function of CD-4+ CD-25+ regulatory T cells in the peripheral blood of patients with aggressive periodontitis.Methods Flow cytometric analysis was used to detect the frequency of CD-4+ CD-25+ regulatory T cells in the peripheral blood of 16 patients with generalized aggressive periodontitis and 17 patients with chronic periodontitis,as well as 17 periodontal healthy controls.Furthermore,CD-4+ CD-25+ regulatory T cells and CD-4+ CD-25- T cells were separated from peripheral blood of each enrolling subject using magnetic cell sorting technology.The direct suppression effect of CD-4+ CD-25+ regulatory T cells on CD-4+ CD-25- T lymphocytes proliferation was performed by the mixed lymphocytes reaction and measured by 3H-thymidine radioactive assay.Results The patients with generalized aggressive periodontitis had a lower frequency of CD-4+ CD-25+ regulatory T cells(9.71±4.01)%in the peripheral blood than periodontal healthy controls [(14.72±3.51)%]and chronic periodontitis patients[(17.01±5.16 )%],P＜0.05.A significant decrease was found in the suppression function of CD-4+ CD-25+ regulatory T cells from peripheral blood of patients with generalized aggressive periodontitis when co-cultured with CD-4+ CD-25- T lymphocytes in the proportion of 2:1,1:1 and 1:2 as compared with chronic periodontitis patients and periodontal healthy controls(P＜0.05).Conclusions Diminished numbers and decreased suppression function of CD-4+ CD-25+ regulatory T cells were found in patients with generalized aggressive periodontitis.