Signs Of Bottleneck Research Articles

Small but Mighty: Genetic Diversity of the Thai Ridgeback Dog Population.

Originating in Thailand, the Thai Ridgeback dog is known for its unique fur ridge that grows in the opposite direction along its back. Selective breeding and a limited populations in Thailand have led to significant close inbreeding among related individuals. The current Thai Ridgeback population is assumed to have experienced a loss of genetic diversity and bottleneck events. Furthermore, studies on the genetic diversity and structure of Thai Ridgeback dogs are limited. Therefore, the aim of this study was to assess the genetic diversity in Thai Ridgeback dogs. Microsatellite genotyping and mitochondrial DNA D-loop sequences were used to assess genetic diversity in 105 Thai Ridgeback dogs from various farms throughout Thailand. Significant genetic diversity and minimal inbreeding were observed in the current Thai Ridgeback population. Signs of bottlenecks were not observed because the exchange of genetic material among Thai Ridgeback owners effectively preserved the genetic diversity. Moreover, the genetic parameters in this study supported owner-to-owner exchanges animals for mating programs. To sustain the genetic diversity of Thai Ridgeback dogs, the use of genetic parameters to manage genetic closeness while preserving breed characteristics is essential. These data are crucial for ensuring demographic stability, which is pivotal for long-term conservation and effective population management.

Association of contrast enhancement of proximal internal carotid artery wall and champagne bottle neck sign with ipsilateral stroke in moyamoya disease patients

ObjectiveTo investigate the characteristics of the proximal internal carotid artery (ICA) and their relationships with ipsilateral intracranial stroke in sufferers of moyamoya disease (MMD) with champagne bottle neck sign (CBNS). Patients and methodsForty-four patients with MMD（mean age 43.98 ± 10.54 years, 21 males）confirmed by digital subtraction angiography were enrolled and carotid magnetic resonance vessel wall imaging was introduced in this study. CBNS was defined as the ratio of the diameters of proximal ICA to the common carotid artery (CCA) (DpICA/CCA) < 0.5. The wall thickness and enhancement of the proximal ICA was measured on postcontrast T1-VISTA images. The correlations between these characteristics of the proximal ICA and ipsilateral intracranial stroke were analysed. ResultsAmong the 44 patients with MMD, twelve patients (27.3 %) had bilateral CBNS and fourteen patients (31.8 %) without CBNS. Compared with normal extracranial arteries, in arteries with CBNS, the proximal ICA had a smaller diameter (3.03 ± 1.05 mm vs 3.95 ± 1.10 mm, p < 0.001), the maximum wall thickness of the proximal ICA was thicker (1.34 ± 0.31 mm vs 1.06 ± 0.26 mm, p < 0.001), and arterial wall contrast enhancement was more frequently observed (66.7 % vs 2 %, p = 0.001). Logistic regression analysis revealed that the wall enhancement of the proximal ICA with CBNS (OR = 15.16, 95 % CI, 2.32–99.02; P = 0.005) was independently associated with intracranial multiple lesions. The AUC of the wall enhancement of the proximal ICA with CBNS was 0.79(P = 0.003). ConclusionsVessel wall enhancement of the proximal ICA with CBNS is independently associated with intracranial stroke in the ipsilateral hemispheres of patients with MMD, particularly those with multiple lesions.

Champagne bottle neck sign with Moyamoya disease.

Champagne bottle neck sign with Moyamoya disease.

The angiographic presentation of European Moyamoya angiopathy

Background and purposeLittle is known about the angiographic presentation of Moyamoya angiopathy (MMA) in non-Asian patients.MethodsConventional cerebral angiograms from 155 Caucasian patients diagnosed as MMA were analyzed with respect to extracranial champagne bottle neck sign, Suzuki stages, collateral status, as well as presence of aneurysms and posterior cerebral artery stenosis.ResultsIn 84 of 155 angiograms, the extracranial carotid artery was visualized, in 65 of them (77.4%), a champagne bottle neck sign was noted. Of the 278 analyzable hemispheres, 13.7%,11.2%, 37.8%, 27.3%, 8.6%, and 1.4% were classified as Suzuki stage I, stage II, stage III, stage IV, stage V, and stage VI, respectively. Among 280 hemispheres, in 53 hemispheres (18.9%) isolated basal collaterals (pathway I) and in 104 hemispheres (37.1%) choroidal and pericallosal collaterals (including basal collaterals, pathway II) were found. In 74 hemispheres (26.4%) ethmoidal collaterals (pathways III), and in 17 hemispheres (6.1%) vault collaterals were visualized. Patients with higher Suzuki stages IV–VI (p = 0.008) and ethmoidal collaterals (p < 0.001) suffered more often from cerebral hemorrhage. Transient ischemic attacks occurred more frequently in patients with Suzuki stage I to III (p < 0.001). In 10 of 155 patients (6.5%), the angiogram revealed a cerebral aneurysm. In 13 patients (8.4%), a stenotic P1 segment of the posterior cerebral artery was found.ConclusionsThis is so far the largest observational study about angiography in Caucasian European MMA patients. A comparison with Asian data indicates similarity of disease in Caucasian and Asian patients.

Progressive stenosis and radiological findings of vasculitis over the entire internal carotid artery in moyamoya vasculopathy associated with graves\u2019 disease: a case report and review of the literature

BackgroundMoyamoya vasculopathy (MMV) associated with Graves’ disease (GD) is a rare condition resulting in ischemic stroke accompanied by thyrotoxicity. Radiological findings of vasculitis have been reported in the walls of distal internal carotid arteries (ICAs) in these patients; however, no reports have described in detail the processes of progression of the lesions in the proximal ICA. Moreover, treatments to prevent recurrence of ischemic stroke and progression of MMV have not yet been sufficiently elucidated.Case presentationWe report a progressive case of MMV associated with GD and review the literature to clarify relationships among recurrence, progression, thyrotoxicity and treatment. Our patient developed cerebral infarction during thyrotoxicity with no obvious stenosis of ICAs. Five months later, transient ischemic attacks recurred with thyrotoxicity. Antiplatelet therapy and intravenous methylprednisolone stopped the attacks. Stenosis of the left ICA from the proximal to distal portion and champagne bottle neck sign (CBN) were found. She declined any surgery. Afterward, gradual progression with mild thyrotoxicity was observed. Eventually, we found smooth, circumferential, concentric wall thickening with diffuse gadolinium enhancement of the left ICA from the proximal to the distal portion on T1-weighted imaging, suggesting vasculitis radiologically. The clinical and radiological similarities to Takayasu arteritis encouraged us to provide treatment as for vasculitis of medium-to-large vessels. In a euthyroid state and after administration of prednisolone and methotrexate, improved flow in the cerebrovascular arteries on magnetic resonance angiography was observed. Based on our review of the literature, all cases with recurrence or progression were treated with anti-thyroid medication (ATM) alone and accompanied by thyrotoxicity. CBN was observed in all previous cases for which images of the proximal ICA were available.ConclusionsWe report the details of progressive stenosis from a very early stage and radiological findings of vasculitis over the entire ICA in MMV associated with GD. Cerebral infarction can occur with no obvious stenosis of the ICA. We treated the patient as per vasculitis of a medium-to-large vessel. Management of GD by ATM alone seems risky in terms of recurrence. Adequate management of GD and possible vasculitis may be important for preventing recurrence and progression.

Association Between Champagne Bottle Neck Sign of Internal Carotid Artery and Ipsilateral Hemorrhagic Stroke in Patients with Moyamoya Disease

To assess association between champagne bottle neck sign (CBNS) in carotid artery and intracranial hemorrhage in patients with moyamoya disease (MMD). This retrospective study included 76 consecutive patients with MMD without definite risk factors associated with intracranial hemorrhage who underwent preoperative angiography from January 2016 to December 2017. CBNS was defined as luminal diameter ratio of internal carotid artery/common carotid artery ≤0.5 on angiography. The right and left cerebral hemisphere in each patient was separately identified as hemorrhagic and nonhemorrhagic. Association between CBNS and intracranial hemorrhage was analyzed. Of 76 patients with MMD, intracranial hemorrhage was found in 44 of 152 (28.9%) hemispheres, and 6.8% (3/44) had multiple events. Comparing carotid arteries without intracranial hemorrhage in ipsilateral hemispheres, patients with intracranial hemorrhage in the ipsilateral hemisphere had significantly smaller luminal diameter ratio of internal carotid artery/common carotid artery (0.49 ± 0.11 vs. 0.55 ± 0.12, P < 0.01) and higher prevalence of CBNS (63.7% vs. 41.7%, P= 0.01). Comparing hemispheres with intracranial hemorrhage, patients with ipsilateral carotid artery CBNS had significantly higher prevalence of hemorrhage in posterior territories than patients without CBNS (57.1% vs. 23.1%, P= 0.05). Logistic regression revealed that CBNS was significantly associated with ipsilateral intracranial hemorrhage before (odds ratio= 2.45; 95% confidence interval, 1.19-5.05; P= 0.02) and after (odds ratio= 3.43; 95% confidence interval, 1.50-7.87; P < 0.01) adjusting for female sex, lenticulostriate anastomosis, and choroidal anastomosis. CBNS is significantly associated with intracranial hemorrhage in the ipsilateral hemisphere in patients with MMD, particularly intracranial hemorrhage in posterior territories.

Unilateral moyamoya disease with ipsilateral carotid canal hypoplasia: A case report

Abstract A 41-year-old Korean man was admitted to our hospital with a 1-day history of headache and abnormal left visual field. Neurological examination revealed left homonymous hemianopia and difficulty in fine movement of the left finger. Laboratory studies indicated hyperlipidemia and hyperhomocysteinemia. Diffusion-weighted imaging showed a hyperintense signal on the right posterior cerebral-middle cerebral artery watershed area. Computed tomography angiography and carotid angiography revealed the bottle neck sign on the right internal carotid artery (ICA) with occlusion of the distal right ICA, but not the left ICA. Carotid angiography showed moyamoya vessels as well as occlusion of the distal right ICA. The right carotid canal was hypoplasic. We diagnosed the patient with unilateral moyamoya disease and carotid canal hypoplasia. This case demonstrates that unilateral carotid canal hypoplasia may co-exist with ipsilateral moyamoya disease. A unilateral bottle neck sign may indicate the presence of carotid canal hypoplasia. Evaluation of the bony carotid canal may be useful when it is necessary to distinguish between secondary vascular stenosis due to arteriosclerosis and MMD.

頸動脈超音波所見“Champagne bottle neck sign”の両側陽性例と片側陽性例の背景因子の差異に関する検討

頸動脈超音波所見“Champagne bottle neck sign”の両側陽性例と片側陽性例の背景因子の差異に関する検討

Population structure and connectivity in the Mediterranean sponge Ircinia fasciculata are affected by mass mortalities and hybridization.

Recent episodes of mass mortalities in the Mediterranean Sea have been reported for the closely related marine sponges Ircinia fasciculata and Ircinia variabilis that live in sympatry. In this context, the assessment of the genetic diversity, bottlenecks and connectivity of these sponges has become urgent in order to evaluate the potential effects of mass mortalities on their latitudinal range. Our study aims to establish (1) the genetic structure, connectivity and signs of bottlenecks across the populations of I. fasciculata and (2) the hybridization levels between I. fasciculata and I. variabilis. To accomplish the first objective, 194 individuals of I. fasciculata from 12 locations across the Mediterranean were genotyped at 14 microsatellite loci. For the second objective, mitochondrial cytochrome c oxidase subunit I sequences of 16 individuals from both species were analyzed along with genotypes at 12 microsatellite loci of 40 individuals coexisting in 3 Mediterranean populations. We detected strong genetic structure along the Mediterranean for I. fasciculata, with high levels of inbreeding in all locations and bottleneck signs in most locations. Oceanographic barriers like the Almeria-Oran front, North-Balearic front and the Ligurian-Thyrrenian barrier seem to be impeding gene flow for I. fasciculata, adding population divergence to the pattern of isolation by distance derived from the low dispersal abilities of sponge larvae. Hybridization between both species occurred in some populations that might be increasing genetic diversity and somewhat palliating the genetic loss caused by population decimation in I. fasciculata.

Clinical Significance of the Champagne Bottle Neck Sign in the Extracranial Carotid Arteries of Patients with Moyamoya Disease.

The champagne bottle neck sign represents a rapid reduction in the extracranial ICA diameters and is a characteristic feature of Moyamoya disease. However, the clinical significance of the champagne bottle neck sign is unclear. We investigated the relationship between the champagne bottle neck sign and the clinical and hemodynamic stages of Moyamoya disease. We analyzed 14 patients with Moyamoya disease before revascularization (5 men, 9 women; age, 43.2 ± 19.3 years). The ratio of the extracranial ICA and common carotid artery diameters was determined using carotid ultrasonography or cerebral angiography; a ratio of < 0.5 was considered champagne bottle neck sign-positive. The clinical disease stage was determined using the Suzuki angiographic grading system. CBF and cerebral vasoreactivity also were measured. The ICA/common carotid artery ratio (expressed as median [interquartile range]) decreased as the clinical stage advanced (stages I-II, 0.71 [0.60-0.77]; stages III-IV, 0.49 [0.45-0.57]; stages V-VI, 0.38 [0.34-0.47]; P < .001). Lower ICA/common carotid artery ratio tended to occur in symptomatic versus asymptomatic arteries (0.47 [0.40-0.53] versus 0.57 [0.40-0.66], respectively; P = .06). Although the ICA/common carotid artery ratio was not related to cerebral perfusion, it decreased as cerebral vasoreactivity decreased (P < .01). All champagne bottle neck sign-positive arteries were classified as Suzuki stage ≥III, 73% were symptomatic, and 89% exhibited reduced cerebral vasoreactivity. In contrast, all champagne bottle neck sign-negative arteries were Suzuki stage ≤III, 67% were asymptomatic, and all showed preserved cerebral vasoreactivity. The champagne bottle neck sign was related to advanced clinical stage, clinical symptoms, and impaired cerebral vasoreactivity. Thus, detection of the champagne bottle neck sign might be useful in determining the clinical and hemodynamic stages of Moyamoya disease.

もやもや病における Champagne bottle neck sign と内頸動脈血流動態との関連性

【目的】もやもや病患者のChampagne bottle neck sign（CBNS）と内頸動脈（ICA）血流の関連を調べる．【方法】もやもや病で脳血管造影，頸部血管超音波検査を受けた108 例を対象とし，病期とCBNS の関係やCBNS と後交通動脈（Pcom）の開存の有無，ICA pulsatility index（PI）やmean velocity （MV）との関係を解析した．【結果】3 期以降でCBNS 陽性率は上昇し，Pcom 開存はCBNS 陽性例で少なかった（67.0％ vs. 86.7％，p<0.001）．陽性側ではPI は高く（1.30±0.34 vs. 1.02±0.12，p=0.027）， MV は低かった（33.8±3.6 vs. 45.6±3.2 cm/s，p<0.001）．【結論】CBNS は病期進行に伴うPcom 脱落やICA 血管抵抗上昇に伴う血流速度低下と関連すると推察される．

High and distinct range-edge genetic diversity despite local bottlenecks.

The genetic consequences of living on the edge of distributional ranges have been the subject of a largely unresolved debate. Populations occurring along persistent low latitude ranges (rear-edge) are expected to retain high and unique genetic diversity. In contrast, currently less favourable environmental conditions limiting population size at such range-edges may have caused genetic erosion that prevails over past historical effects, with potential consequences on reducing future adaptive capacity. The present study provides an empirical test of whether population declines towards a peripheral range might be reflected on decreasing diversity and increasing population isolation and differentiation. We compare population genetic differentiation and diversity with trends in abundance along a latitudinal gradient towards the peripheral distribution range of Saccorhiza polyschides , a large brown seaweed that is the main structural species of kelp forests in SW Europe. Signatures of recent bottleneck events were also evaluated to determine whether the recently recorded distributional shifts had a negative influence on effective population size. Our findings show decreasing population density and increasing spatial fragmentation and local extinctions towards the southern edge. Genetic data revealed two well supported groups with a central contact zone. As predicted, higher differentiation and signs of bottlenecks were found at the southern edge region. However, a decrease in genetic diversity associated with this pattern was not verified. Surprisingly, genetic diversity increased towards the edge despite bottlenecks and much lower densities, suggesting that extinctions and recolonizations have not strongly reduced diversity or that diversity might have been even higher there in the past, a process of shifting genetic baselines.

Genetic Structure and Inferences on Potential Source Areas for Bactrocera dorsalis (Hendel) Based on Mitochondrial and Microsatellite Markers

Bactrocera dorsalis (Diptera: Tephritidae) is mainly distributed in tropical and subtropical Asia and in the Pacific region. Despite its economic importance, very few studies have addressed the question of the wide genetic structure and potential source area of this species. This pilot study attempts to infer the native region of this pest and its colonization pathways in Asia. Combining mitochondrial and microsatellite markers, we evaluated the level of genetic diversity, genetic structure, and the gene flow among fly populations collected across Southeast Asia and China. A complex and significant genetic structure corresponding to the geographic pattern was found with both types of molecular markers. However, the genetic structure found was rather weak in both cases, and no pattern of isolation by distance was identified. Multiple long-distance dispersal events and miscellaneous host selection by this species may explain the results. These complex patterns may have been influenced by human-mediated transportation of the pest from one area to another and the complex topography of the study region. For both mitochondrial and microsatellite data, no signs of bottleneck or founder events could be identified. Nonetheless, maximal genetic diversity was observed in Myanmar, Vietnam and Guangdong (China) and asymmetric migration patterns were found. These results provide indirect evidence that the tropical regions of Southeast Asia and southern coast of China may be considered as the native range of the species and the population expansion is northward. Yunnan (China) is a contact zone that has been colonized from different sources. Regions along the southern coast of Vietnam and China probably served to colonize mainly the southern region of China. Southern coastal regions of China may also have colonized central parts of China and of central Yunnan.

Spatial and Temporal Genetic Variation of Green Mussel, Perna viridis in the Gulf of Thailand and Implication for Aquaculture

The culture of green mussel (Perna viridis) in the Gulf of Thailand depends on natural spat which are believed to come from spawning grounds adjacent to major river mouths. In the present paper, genetic diversity of spatial and temporal populations of green mussel in the Gulf of Thailand was investigated using five microsatellite loci. The results showed moderate genetic variation of all 11 populations (averaged number of alleles per locus, A = 10.4-12.2; effective number of alleles per locus, A(e) = 5.36-6.59; mean allelic richness, A(r) = 10.23-12.06; observed heterozygosity, H(o) = 0.52-0.63, and expected heterozygosity, H(e) = 0.66-0.73) without significant differences among populations. No sign of bottleneck or genetic disequilibrium was observed. Genetic differentiation among spatial populations was low (F (ST) = 0.0046, CI(0.95) = 0.0020-0.0083 for the samples collected in January, 2007, and F (ST) = 0.0088, CI(0.95) = 0.0010-0.0162 for the samples collected in July, 2007) while temporal variation was significant as revealed by the analysis of molecular variance. Multidimensional scaling separated temporal population groups with minor exception. The assignment test revealed that most of the recruits were from other populations.

Bottle Neck Sign of the Proximal Portion of the Internal Carotid Artery in Moyamoya Disease

We investigated morphologic features of the extracranial internal carotid artery (ICA) by carotid ultrasonography in patients with moyamoya disease. We performed conventional carotid ultrasonography and transoral carotid ultrasonography on 19 ICAs in 10 patients with moyamoya disease (moyamoya group) and 28 ICAs in 14 control subjects (control group). We evaluated whether the diameter was greatly reduced at the proximal portion of the ICA above the bulbus, like a champagne bottle neck, to be less than half that of the common carotid artery and whether the diameter of the ICA was smaller than that of the external carotid artery (diameter reversal) on conventional carotid ultrasonography. We then measured the internal diameter of the extracranial distal ICA by transoral carotid ultrasonography. We compared the incidence of a "bottle neck" appearance, diameter reversal, and the ICA diameter between the 2 groups. The bottle neck and diameter reversal were shown in 14 (74%) and 16 (84%) of the 19 ICAs in the moyamoya group, respectively (chi2 test, P<.0001). However, neither of them was shown in the control group. The diameter of the distal ICA in the moyamoya group was significantly smaller than that in the control group (mean+/-SD, 2.4+/-0.60 versus 4.1+/-0.52 mm; unpaired t test, P<.0001). These results suggest that rapid internal diameter reduction at the proximal portion of the ICA, characterized by a bottle neck appearance or diameter reversal, is an important morphologic feature of moyamoya disease.