Limited Genetic Diversity in Polynesians Reflected in the Highly Polymorphic 3&amp;rsquo;HVR&amp;alpha;-Globin Gene Marker

Hertzberg, Magnus; Mickleson, K. N. P.; Trent, R. J.

doi:10.1159/000154059

Cited by 14 publications

(12 citation statements)

References 6 publications

(10 reference statements)

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“…These include studies related to the immune system [T cell receptor polymorphism (54) and HLA polymorphism (see, for example, refs. 21, 55, and 56)], globin gene markers (57), hemophilia (58), minisatellites (23), and variable numbers of tandem repeats (59). In general, these studies show genes with restricted diversity and types, combinations, and͞or frequencies different from Caucasians.…”

Section: Discussionmentioning

confidence: 91%

Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences

Murray‐McIntosh

Scrimshaw

Hatfield

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

102

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The hypervariable 1 region of human mtDNA shows markedly reduced variability in Polynesians, and this variability decreases from western to eastern Polynesia. Fiftyfour sequences from New Zealand Maori show that the mitochondrial variability with just four haplotypes is the lowest of any sizeable human group studied and that the frequency of haplotypes is markedly skewed. The Maori sequences, combined with 268 published sequences from the Pacific, are consistent with a series of founder effects from small populations settling new island groups. The distributions of haplotypes were used to estimate the number of females in founding population of New Zealand Maori. The three-step simulation used a randomly selected founding population from eastern Polynesia, an expansionary phase in New Zealand, and finally the random selection of 54 haplotypes. The results are consistent with a founding population that includes Ϸ70 women (between 50 and 100), and sensitivity analysis shows that this conclusion is robust to small changes in haplotype frequencies. This size is too large for models postulating a very small founding population of ''castaways,'' but it is consistent with a general understanding of Maori oral history as well as the results of recent canoe voyages recreating early trans-oceanic voyages.

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Section: Discussionmentioning

confidence: 91%

Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences

Murray‐McIntosh

Scrimshaw

Hatfield

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

102

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“…As previously reported, early recanalization influences recovery positively [1,2,3,4,5, 14, 16, 17]. Using TCD Alexandrov et al [4] studied 40 acute MCA stroke patients treated with intravenous thrombolytic therapy.…”

Section: Discussionmentioning

confidence: 99%

“…Dramatic neurological improvement shortly after acute stroke of the middle cerebral artery (MCA) has previously been described as spectacular shrinking deficit (SSD) [1, 2]. Only scarce information on the prevalence and pathomechanisms of SSD is available [1,2,3,4,5].…”

Section: Introductionmentioning

confidence: 99%

“…Only scarce information on the prevalence and pathomechanisms of SSD is available [1,2,3,4,5]. Minematsu et al [2] assumed rapid migration of the thrombus as the underlying mechanism of dramatic recovery and regarded SSD to primarily be a feature of cardiogenic emboli. Using single-photon electron computed tomography (SPECT), Baird et al [1] demonstrated reperfusion to be responsible for dramatic recovery.…”

Section: Introductionmentioning

confidence: 99%

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Magnetic Resonance Imaging and Clinical Patterns of Patients with ‘Spectacular Shrinking Deficit’ after Acute Middle Cerebral Artery Stroke

Kraemer

Thomalla²,

Soennichsen³

et al. 2005

Cerebrovasc Dis

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Background: Rapid resolution of neurological deficits after severe middle cerebral artery (MCA) stroke has been coined spectacular shrinking deficit (SSD). We studied clinical and MRI patterns in patients with SSD. Methods: Patients with acute MCA stroke <6 h were examined by stroke MRI (perfusion- and diffusion-weighted imaging (PWI, DWI), MR angiography (MRA)) at admission, day 1 and day 7. SSD was defined as a ≧8-point-reduction of neurological deficit in the National Institute of Health Stroke Scale (NIHSS) to a score of ≤4 within 24 h. PWI and DWI lesion volumes were measured on ADC (ADC < 80%) and time to peak maps (TTP > +4 s). Recanalization was assessed by MRA after 24 h. Final infarct volumes were defined on T2 weighted images at day seven. Outcome was assessed after 90 days using modified Rankin Scale (mRS) and Barthel Index (BI). Results: SSD was present in 14 of 104 patients. Initial DWI and PWI lesion volumes were smaller in SSD patients – ADC < 80%: 8.9 (4.3–20.5) vs. 30 (0–266.7) ml; TTP > +4 s: 91.6 (29.7–205.8) vs. 131.5 (0–311.5) ml. Early recanalization was associated with SSD resulted in smaller final infarct volumes (11.9 (2.4–25.9) vs. 47.7 (1.2–288.5)). All SSD patients were independent at day 90 (mRS 0 (0–2); BI 100). Conclusion: The clinical syndrome of SSD is reflected by a typical MRI pattern with small initial DWI and PWI lesion volumes, timely recanalization and small final infarct volumes.

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“…Two (nonmutually exclusive) mechanisms, both taking place in the salvaged penumbra, underlie this correlation. The first is immediate return of neuronal function, which would account for the spectacular full recovery occasionally observed within 3 days of onset, so-called spectacular shrinking deficit [6]. The second, which would account for the gradual recovery over weeks and months, is neuronal reorganization in the infarct rim [5], also documented by cortical mapping in monkeys [7].…”

Section: Introductionmentioning

confidence: 99%

How Healthy Is the Acutely Reperfused Ischemic Penumbra?

Baron

2005

Cerebrovasc Dis

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Because it is the main determinant of clinical recovery, early reperfusion of the ischemic penumbra has become the mainstay of acute stroke therapy. Although early permanent recanalization can be associated with spectacular and complete recovery, some patients in fact exhibit delayed or incomplete recovery, even despite small infarcts on late structural imaging. This might result from tissue inflammation and selective neuronal death/damage, two probably inter-related cellular events well described in the animal literature, precluding full functional restoration in the salvaged penumbra. However, impact of these processes on recovery may be complex because of the interplay with ongoing plasticity and the possible promoting effect of inflammation on the latter. Preliminary results from imaging studies of inflammation and selective neuronal loss after middle cerebral artery territory stroke, using radioligands of the central benzodiazepine receptor and the activated microglia, respectively, reviewed here, suggest these phenomena also exist in man, although their relationship with acute-stage hypoperfusion and their impact on clinical recovery, if any, remain poorly understood. Furthermore, their inter-relationships in the salvaged penumbra have not been addressed. Better understanding of these potentially harmful processes might help to maximize benefits from thrombolysis, and could also have implications for patients who enjoy spontaneous recanalization.

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Limited Genetic Diversity in Polynesians Reflected in the Highly Polymorphic 3’HVRα-Globin Gene Marker

Cited by 14 publications

References 6 publications

Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences

Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences

Magnetic Resonance Imaging and Clinical Patterns of Patients with ‘Spectacular Shrinking Deficit’ after Acute Middle Cerebral Artery Stroke

How Healthy Is the Acutely Reperfused Ischemic Penumbra?

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