Phylogeographic study of Apodemus ilex (Rodentia: Muridae) in Southwest China

Background

The Mountains of southwest China have complex river systems and a profoundly complex topography and are among the most important biodiversity hotspots in the world. However, only a few studies have shed light on how the mountains and river valleys promote genetic diversity. Apodemus ilex is a fine model for investigating this subject.

Methodology/Principal Findings

To assess the genetic diversity and biogeographic patterns of Apodemus ilex, the complete cytochrome b gene sequences (1,140 bp) were determined from 203 samples of A. draco/ilex that were collected from southwest China. The results obtained suggested that A. ilex and A. draco are sistergroups and diverged from each other approximately 2.25 million years ago. A. ilex could be divided into Eastern and Western phylogroups, each containing two sub-groups and being widespread in different geographical regions of the southern Hengduan Mountains and the western Yunnan - Guizhou Plateau. The population expansions of A. ilex were roughly from 0.089 Mya to 0.023 Mya.

Conclusions

Our result suggested that A. ilex is a valid species rather than synonym of A. draco. As a middle-high elevation inhabitant, the phylogenetic pattern of A. ilex was strongly related to the complex geographical structures in southwest China, particularly the existence of deep river valley systems, such as the Mekong and Salween rivers. Also, it appears that the evolutionary history of A. ilex, such as lineage divergences and population expansions were strongly affected by climate fluctuation in the Late Pleistocene.     

Longitudinal assessment of antisaccades in patients with multiple sclerosis

We have previously demonstrated that assessment of antisaccades (AS) provides not only measures of motor function in multiple sclerosis (MS), but measures of cognitive control processes in particular, attention and working memory. This study sought to demonstrate the potential for AS measures to sensitively reflect change in functional status in MS. Twenty-four patients with relapsing-remitting MS and 12 age-matched controls were evaluated longitudinally using an AS saccade task. Compared to control subjects, a number of saccade parameters changed significantly over a two year period for MS patients. These included saccade error rates, latencies, and accuracy measures. Further, for MS patients, correlations were retained between OM measures and scores on the PASAT, which is considered the reference task for the cognitive evaluation of MS patients. Notably, EDSS scores for these patients did not change significantly over this period. These results demonstrate that OM measures may reflect disease evolution in MS, in the absence of clinically evident changes as measured using conventional techniques. With replication, these markers could ultimately be developed into a cost-effective, non-invasive, and well tolerated assessment tool to assist in confirming progression early in the disease process, and in measuring and predicting response to therapy.     

The Biological Variation of N-Terminal Pro-Brain Natriuretic Peptide in Postmenopausal Women with Type 2 Diabetes: A Case Control Study

Background

The incidence of heart failure in type 2 diabetes is high and it has poorer prognosis when compared with patients without diabetes. Access to echocardiography is limited and alternative methods to identify early heart failure such as the measurement of natriuretic peptides levels have been proposed. However, their wide biological variation could limit their clinical utility. Our aim was to determine if the intrinsic biological variation of one of these peptides, N-terminal proBNP, is as wide in type 2 diabetes as it is in health and to calculate the critical difference values that could be utilised in clinical practice to ensure changes observed between two samples are due to intervention rather than to its biological variability.

Methodology/Principal Findings

12 postmenopausal women with diet controlled type 2 diabetes and without heart failure were compared with 11 control postmenopausal women without diabetes. N-terminal proBNP levels were measured on 10 occasions. The biological variation was calculated according to Fraser''s methods. The mean NT-proBNP level was similar in both groups (mean ± standard deviation; type 2 diabetes, 10.7 pmol/L± 8.5 versus 8.49±6.0 pmol/L, p = 0.42). The biological variation was also similarly wide. The critical difference in patients with type 2 diabetes was between −70% and ±236%.

Conclusions

Type 2 diabetes does not appear to significantly influence the marked biological variation of N-terminal proBNP in postmenopausal women. The critical difference values reported in this study could be used to titrate therapy or monitor response to interventions although the change required in between samples is wide and this might limit its utility.     

Optic Nerve Magnetisation Transfer Ratio after Acute Optic Neuritis Predicts Axonal and Visual Outcomes

Magnetisation transfer ratio (MTR) can reveal the degree of proton exchange between free water and macromolecules and was suggested to be pathological informative. We aimed to investigate changes in optic nerve MTR over 12 months following acute optic neuritis (ON) and to determine whether MTR measurements can predict clinical and paraclinical outcomes at 6 and 12 months. Thirty-seven patients with acute ON were studied within 2 weeks of presentation and at 1, 3, 6 and 12 months. Assessments included optic nerve MTR, retinal nerve fibre layer (RNFL) thickness, multifocal visual evoked potential (mfVEP) amplitude and latency and high (100%) and low (2.5%) contrast letter acuity. Eleven healthy controls were scanned twice four weeks apart for comparison with patients. Patient unaffected optic nerve MTR did not significantly differ from controls at any time-point. Compared to the unaffected nerve, affected optic nerve MTR was significantly reduced at 3 months (mean percentage interocular difference = −9.24%, p = 0.01), 6 months (mean = −12.48%, p<0.0001) and 12 months (mean = −7.61%, p = 0.003). Greater reduction in MTR at 3 months in patients was associated with subsequent loss of high contrast letter acuity at 6 (ρ = 0.60, p = 0.0003) and 12 (ρ = 0.44, p = 0.009) months, low contrast letter acuity at 6 (ρ = 0.35, p = 0.047) months, and RNFL thinning at 12 (ρ = 0.35, p = 0.044) months. Stratification of individual patient MTR time courses based on flux over 12 months (stable, putative remyelination and putative degeneration) predicted RNFL thinning at 12 months (F _2,32 = 3.59, p = 0.02). In conclusion, these findings indicate that MTR flux after acute ON is predictive of axonal degeneration and visual disability outcomes.     

Parasite Threat to Panda Conservation

The giant panda is a global symbol of wildlife conservation that is threatened by historic and current habitat loss. Despite a great deal of research on the physiology, reproductive biology, and diet of pandas in the wild and in captivity, there is little information on wild panda mortality. Here we integrate previously unavailable data on the mortality of wild pandas. We report on three recent phases of panda mortality: deaths due to bamboo flowering in the 1970s and 1980s, surprisingly extensive poaching in the 1980s and 1990s, and a parasitic infection over the past few years. Our analyses suggest that the current most significant threat to wild panda survival is disease due to extraintestinal migration (visceral larval migrans) by an ascarid nematode. We demonstrate that the probability of death of wild pandas being caused by this disease increased significantly between 1971 and 2005 and discuss the possible factors leading to the emergence of this disease. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Biosynthetic relationship between the major matrix proteins of adrenal chromaffin granules

The matrix of the chromaffin granule contains a family of acidic proteins, collectively known as the chromogranins. It has been suggested that this family results from protease action on the major component, chromogranin A. Evidence for this has now been obtained from in vitro translation of adrenal medullary messenger RNA and immunoprecipitation of translation products using an antiserum directed against chromogranin A, but which also recognises other chromogranins.     

The nucleotide sequence of glycine tRNA from Mycoplasma mycoides sp. capri.

Using in vitro labelling techniques, a tRNAGly from M. mycoides sp. capri PG3 has been shown to have the sequence : pGCAGGUGs4UAGUUUAAUGGCAGAACUUC AGCCUUCCm6AAGCUGAUUGUGAGGGU psi CGAUUCCCUUCACCUGCUCCAOH. The anticodon is UCC and no other tRNAGly has been detected in the crude tRNA isolated from this organism. As is the case with some mitochondrial tRNAs, where the genome size of the organelle is small, it is possible that this tRNA is used to read all four glycine codons GGN.