Ascending contraction and descending relaxation in the distal colon of mice lacking interstitial cells of Cajal.

Recently an essential role of interstitial cells of Cajal (ICC) within myenteric plexus (ICC-MY) was suggested in ascending contraction and descending relaxation in the mouse ileum. The role of ICC in these neural reflexes was examined in the distal colonic segments prepared from the wild type and c-kit mutant, W/W(V) mice, in the present study. Localized distension of the segments from the wild type mice by using a small balloon resulted in ascending contraction and descending relaxation. In the segments from the mutant mice, localized distension also induced these neural reflexes similar to those observed in the wild type mice. Immunohistochemical examination demonstrated that ICC-MY and ICC present in muscle layers (ICC-IM) were severely disrupted in the mutant mouse, but only ICC, present within submucosal plexus (ICC-SMP), remained unchanged. In the small strips with ICC-SMP absent prepared from the mutant mouse, electrical field stimulation induced contraction or relaxation in the absence or presence of atropine, respectively. It was suggested that ICC have no important role in the ascending and descending neural reflexes in the mouse distal colon, this is in direct contrast to the role of ICC-MY in the ileum.     

Continuous measurement of oxygen consumption using the reversed fick method

We developed a continuous oxygen consumption (Vo₂) measurement system employed the reversed Fick method, in which Vo₂ in computed from continuously measured sured arterial and mixed venous oxygen saturation assed by pulse oximetry and mixed venous oximetry, respectively, and cardiac output by the heat deprivation technique. This system was compared with the conventional intermittent reversed fick method in 7 patients during surgery and with indirect calorimetry in 4 intensive care unit (ICU) patients. The Vo₂ measured by the continuous reversed Fick method showed a high correlation with those simultaneously measured by the intermittent Fick method (r=0.97,P<0.01) and by indirect calorimetry (r=0.74,P<0.01). The 95% confidence limits (bias±2 SD) of the continuous reversed Fick method were −0.6±45 ml·min⁻¹ with the intermittent Fick method and −31±56 ml·min⁻¹ with indirect calorimetry. The continuous Fick method is in satisfactory agreement with the conventional methods for the measured of Vo₂ and potentially allows for convenient assessment of Vo₂ in critically ill patients. This study was supported in part by Grants-in-Aid for the Encouragement of Young Scientists 01771185 and 04857171 from the Ministry of Education, Science and Culture of Japan     

The relationship between viral RNA, myelin-specific mRNAs, and demyelination in central nervous system disease during Theiler's virus infection.

The DA strain of Theiler's murine encephalomyelitis virus (DAV) causes a chronic demyelinating disease in susceptible mouse strains. To elucidate the pathogenesis of DAV-induced demyelination, the authors investigated the spatial and chronologic relationship between virus (antigen and RNA), myelin-specific mRNAs, and demyelination in DAV-infected mice using immunohistochemistry, in situ hybridization, and slot blot hybridization analyses. In spinal cord white matter, viral RNA was detected easily in ventral root entry zones 1 to 2 weeks after infection. Viral RNA increased to maximum levels by 4 weeks after infection, which was associated with inflammation and mild demyelination. At 8 to 12 weeks after infection, when demyelination became most extensive, viral RNA was significantly decreased. Demyelination did not chronologically or spatially parallel the presence of viral RNA within the spinal cord. Decrease of myelin-specific mRNAs, including myelin-basic protein and proteolipid protein mRNAs, was observed within the demyelinating lesions with or without detectable viral RNA. These results indicate that a viral infection of white matter in the early phase of the infection initiates spinal cord disease leading to demyelination, but later an ongoing immunopathologic process contributes to the presence of extensive demyelination.     

Clinical and genetic characteristics of Stargardt disease in a large Western China cohort: Report 1

Stargardt disease 1 (STGD1) is the most prevalent retinal dystrophy caused by pathogenic biallelic ABCA4 variants. Forty‐two unrelated patients mostly originating from Western China were recruited. Comprehensive ophthalmological examinations, including visual acuity measurements (subjective function), fundus autofluorescence (retinal imaging), and full‐field electroretinography (objective function), were performed. Next‐generation sequencing (target/whole exome) and direct sequencing were conducted. Genotype grouping was performed based on the presence of deleterious variants. The median age of onset/age was 10.0 (5–52)/29.5 (12–72) years, and the median visual acuity in the right/left eye was 1.30 (0.15–2.28)/1.30 (0.15–2.28) in the logarithm of the minimum angle of resolution unit. Ten patients (10/38, 27.0%) showed confined macular dysfunction, and 27 (27/37, 73.7%) had generalized retinal dysfunction. Fifty‐eight pathogenic/likely pathogenic ABCA4 variants, including 14 novel variants, were identified. Eight patients (8/35, 22.8%) harbored multiple deleterious variants, and 17 (17/35, 48.6%) had a single deleterious variant. Significant associations were revealed between subjective functional, retinal imaging, and objective functional groups, identifying a significant genotype–phenotype association. This study illustrates a large phenotypic/genotypic spectrum in a large well‐characterized STGD1 cohort. A distinct genetic background of the Chinese population from the Caucasian population was identified; meanwhile, a genotype–phenotype association was similarly represented.     

Fear conditioning-induced plasticity in auditory thalamus and cortex: To what extent is it expressed during slow-wave sleep?

After fear conditioning to a tone, rats received nonawakening presentations of the tone alone during slow-wave sleep (SWS) episodes. Multiunit activity was recorded in the medial part of the medial geniculate (MGm) and in the primary auditory cortex (ACx). Although tone-evoked responses were increased in MGm and ACx during the 3 conditioning sessions, group data failed to show any significant changes during SWS. Nonetheless, the few recordings (5/29) that exhibited the strongest conditioned responses during wakefulness expressed enhanced responding during SWS. Compared with previous data obtained in MGm during paradoxical sleep, associative plastic changes were less easily expressed during SWS. These results are discussed with regard to functional changes that occur in the thalamocortical system across vigilance states.     

Multisystem Inflammatory Syndrome in Adults after Mild SARS-CoV-2 Infection,Japan

In Japan, a 51-year-old man had minimally symptomatic severe acute respiratory syndrome coronavirus 2 infection. Multisystem inflammatory syndrome was diagnosed ≈5 weeks later; characteristics included severe inflammation, cardiac dysfunction, and IgG positivity. Clinicians should obtain detailed history and examine IgG levels for cases of inflammatory disease with unexplained cardiac decompensation.     

Bone Tissue Composition in Postmenopausal Women Varies With Glycemic Control From Normal Glucose Tolerance to Type 2 Diabetes Mellitus

The risk of fragility fracture increases for people with type 2 diabetes mellitus (T2DM), even after controlling for bone mineral density, body mass index, visual impairment, and falls. We hypothesize that progressive glycemic derangement alters microscale bone tissue composition. We used Fourier-transform infrared (FTIR) imaging to analyze the composition of iliac crest biopsies from cohorts of postmenopausal women characterized by oral glucose tolerance testing: normal glucose tolerance (NGT; n = 35, age = 65 ± 7 years, HbA1c = 5.8 ± 0.3%), impaired glucose tolerance (IGT; n = 26, age = 64 ± 5 years, HbA1c = 6.0 ± 0.4%), and overt T2DM on insulin (n = 25, age = 64 ± 6 years, HbA1c = 9.13 ± 0.6). The distributions of cortical bone mineral content had greater mean values (+7%) and were narrower (−10%) in T2DM versus NGT groups (p < 0.05). The distributions of acid phosphate, an indicator of new mineral, were narrower in cortical T2DM versus NGT and IGT groups (−14% and −14%, respectively) and in trabecular NGT and IGT versus T2DM groups (−11% and −10%, respectively) (all p < 0.05). The distributions of crystallinity were wider in cortical NGT versus T2DM groups (+16%) and in trabecular NGT versus T2DM groups (+14%) (all p < 0.05). Additionally, bone turnover was lower in T2DM versus NGT groups (P1NP: −25%, CTx: −30%, ucOC: −24%). Serum pentosidine was similar across groups. The FTIR compositional and biochemical marker values of the IGT group typically fell between the NGT and T2DM group values, although the differences were not always statistically significant. In summary, worsening glycemic control was associated with greater mineral content and narrower distributions of acid phosphate, an indicator of new mineral, which together are consistent with observations of lower turnover; however, wider distributions of mineral crystallinity were also observed. A more mineralized, less heterogeneous tissue may affect tissue-level mechanical properties and in turn degrade macroscale skeletal integrity. In conclusion, these data are the first evidence of progressive alteration of bone tissue composition with worsening glycemic control in humans. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Reinforcement in removable prosthodontics: a literature review

Removable prosthodontics are often associated with mechanical troubles in daily use, such as fracture or deformation. These troubles render prostheses unusable and reduce wearers’ QOL. Various reinforcements are used to prevent such problems, but consensus on reinforcement has not been reached. This review aimed to summarise the effects of reinforcement and to propose favourable reinforcement based on material, design and position in the prostheses. Initially, 139 articles were selected by electronic and manual searches. After exclusion of 99 articles based on the exclusion criteria, 40 articles were finally included in the review. Electronic searches were performed for articles published from 2005 to 2015 in PubMed, EMBASE, MEDLINE and Cochrane Library, and manual searches were performed in 10 journals relevant to the topic of removable prosthodontics. For in vitro studies, certain dental alloys and fibres were mainly used. Their forms were different, including complicated forms in dental alloys and various forms in fibres. The materials were examined for mechanical properties like fracture strength, flexural strength and elastic modulus and compared with one another or without reinforcement. There were a few clinical studies and one longitudinal study. Cast metal reinforcement seemed to be most favourable in terms of fracture toughness and stiffness. The most favourable forms differed depending on the prostheses, but placement around thin and deformable areas was effective. However, randomised or longitudinal clinical reports and comparative clinical studies on the use of reinforcement were still lacking and such studies are necessary in the future.     

Role of Moraxella catarrhalis outer membrane protein CD in bacterial cell morphology and autoaggregation

Moraxella catarrhalis, an important pathogen in the human respiratory tract, causes otitis media and lower respiratory tract infections. M. catarrhalis outer membrane protein CD (OMPCD) is a major heat-modifiable OMP with demonstrable potential as a vaccine candidate. The gene encoding OMPCD of M. catarrhalis strains was subjected to nucleotide sequence analysis and then inactivated by insertional mutagenesis. The ompCD mutant strains exhibited a modest growth defect in comparison with the wild-type strains. In optical microscopy and scanning/transmission electron microscopy examinations, regarding morphology, the cell size and cell wall of the ompCD mutant strains were significantly larger and thinner, respectively, than those of the wild-type strain. Furthermore, the ompCD mutant strains exhibited significant autoaggregation and increased surface hydrophobicity, in addition to a reduction in the adherence to HEp-2 cells, compared to the wild-type strains. Strains repaired by replacing the mutated ompCD gene exhibited phenotypic characteristics very similar to those of the wild-type strains. These results indicate that M. catarrhalis OMPCD, in addition to its functions related to bacterial growth and adherence to human epithelial cells, plays a very important role in bacterial physiology and pathogenesis, including aspects such as stabilizing bacterial cell morphology and preventing autoaggregation by reducing surface hydrophobicity.