Clinical and Radiological Characteristics Associated with Respiratory Failure in Unilateral Lateral Medullary Infarction

BackgroundThe prognosis for unilateral lateral medullary infarction (ULMI) is generally good but may be aggravated by respiratory failure with fatal outcome. Respiratory failure has been reported in patients with severe bulbar dysfunction and large rostral medullary lesions, but its associated factors have not been systematically studied. We aimed to assess clinical and radiological characteristics associated with respiratory failure in patients with pure acute ULMI.Materials and MethodsSeventy-one patients (median age 55 years, 59 males) with MRI-confirmed acute pure ULMI were studied retrospectively. Clinical characteristics were assessed and bulbar symptoms were scored using a scale developed for this study. MRI lesions were classified into 4 groups based on their vertical extent (localized/extensive) and the involvement of the open and/or closed medulla. Clinical characteristics, bulbar scores and MRI lesion characteristics were compared between patients with and without respiratory failure.ResultsRespiratory failure occurred in 8(11%) patients. All patients with respiratory failure were male (p = 0.336), had extensive lesions involving the open medulla (p = 0.061), progression of bulbar symptoms (p=0.002) and aspiration pneumonia (p < 0.001). Peak bulbar score (OR, 7.9 [95% CI, 2.3–160.0]; p < 0.001) and older age (OR, 1.2 [95%CI, 1.0-1.6]; p=0.006) were independently associated with respiratory failure.ConclusionsExtensive damage involving the open/rostral medulla, clinically presenting with severe bulbar dysfunction, in conjunction with factors such as aspiration pneumonia and older age appears to be crucial for the development of respiratory failure in pure ULMI. Further prospective studies are needed to identify other potential risk factors, pathophysiology, and effective preventive measures for respiratory failure in these patients.     

Education modifies the relation of vascular pathology to cognitive function: cognitive reserve in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

A clinical impact of cognitive reserve (CR) has been demonstrated in Alzheimer's disease, whereas its role in vascular cognitive impairment (VCI) is largely unknown. In this study, we investigated the impact of CR in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a genetic variant of pure VCI. A total of 247 NOTCH3 mutation carriers from a two-center study were investigated using detailed neuropsychological and neuroimaging protocols. CR was operationalized as years of formal education. Brain pathology was assessed by MRI using normalized brain volume and lacunar lesion volume as proxies. Multivariate analyses were done for each structural measure with scores of processing speed, executive function, and memory as dependent variables. Additional linear regression models were conducted with interaction terms for education × brain volume and education × lacunar lesion volume. Education had an independent impact on cognitive performance in subjects with mild and moderate degrees of brain pathology, whereas there was no significant influence of education on cognition in patients with severe MRI changes. This interaction was found for processing speed, the cognitive domain most impaired in our patients. Our findings demonstrate an interaction of education and brain pathology in regard to cognitive impairment: the effect of education seems most pronounced in early disease stages but may ultimately be overwhelmed by the pathological changes. The results extend the concept of CR to VCI.     

Rapid turnover of the W chromosome in geographical populations of wild silkmoths, Samia cynthia ssp.

Our previous studies revealed a considerably high level of chromosomal polymorphism in wild silkmoths, Samia cynthia ssp. (Lepidoptera: Saturniidae). Geographical populations of this species complex differ in chromosome numbers and show derived sex chromosome systems including Z0/ZZ in S. cynthia ricini (2n?=?27/28; Vietnam), neo-Wneo-Z/neo-Zneo-Z in S. cynthia walkeri (2n?=?26/26; Sapporo, Hokkaido) and neo-WZ₁Z₂/Z₁Z₁Z₂Z₂ in S. cynthia subsp. indet. (2n?=?25/26; Nagano, Honshu). In this study, we collected specimens of S. cynthia pryeri in Japanese islands Kyushu, Shikoku and Honshu, with an ancestral-like karyotype of 2n?=?28 in both sexes and a WZ/ZZ sex chromosome system, except for one population, in which females have lost the W chromosome. However, the S. cynthia pryeri W chromosome showed a very unusual morphology: It was composed of a highly heterochromatic body, which remained condensed throughout the whole cell cycle and of a euchromatin-like “tail.” We examined molecular composition of the W and neo-W chromosomes in S. cynthia subspecies by comparative genomic hybridisation and fluorescence in situ hybridisation with W chromosome painting probes prepared from laser-microdissected W chromatin of S. cynthia pryeri. These methods revealed that the molecular composition of highly heterochromatic part of the S. cynthia pryeri W chromosome is very different and lacks homology in the genomes of other subspecies, whereas the euchromatin-like part of the W chromosome corresponds to a heterochromatic part of the neo-W chromosomes in S. cynthia walkeri and S. cynthia subsp. indet. Our findings suggest that the curious WZ system of S. cynthia pryeri may represent an ancestral state of the Samia species complex but do not exclude an alternative hypothesis of its derived origin.     

Contribution of bacterial cells as nucleation centers in microbiologically induced CaCO3 precipitation—A mathematical modeling approach

The microbiologically induced calcite precipitation (MICP) has been extensively studied for geotechnical engineering through simultaneous action of natural phenomena and engineering processes. The focus of bacterial contribution to the MICP has been directed to calcium carbonate productivity, while the additional bacterial role as a crystal nucleation center was not explained especially from a mathematical prediction modeling point of view. Therefore, this study provides explanations and a mathematical modeling approach of bacterial influence on the MICP induced by newly-isolated ureolytic Bacillus strains and Sporosarcina pasteurii DSM 33. Using the obtained results of low-cost, rapid, and simple assays, artificial neural network modeling was applied for cell surface predispositions, pH changes as well as calcium-involved function in biofilm formation during the MICP, for the first time. Based on the obtained contribution of the alkalophilic/alkaloresistant bacteria, calcite precipitation can be significantly directed by the presence, of ureolytic bacterial cells as nucleation centers during CaCO₃ precipitation as well as their morphology, surface characteristics, potential to form a biofilm, and/or generate pH changes.