bluuebunny/crossref_metadata_2025 huggingface dataset:
P096 Munchmeyer's disease: an unknown pathology
Authors: Chentouf Amina , Daoud Souad
Published: November 2021

Background

Munchmeyer's disease (MM) or Fibrodysplasia ossificans progressivais an extremely rare genetic disorder characterized by heterotopic ossification of muscle and connective tissue during flare-ups, which can lead to the creation of a true second skeleton. we report an original observation with diagnostic difficulty.

Observation

We report the case of 37-year-old women who consulted for cervical stiffness with painful hypertrophy of the left sternocleidomastoid muscle, dorsal scoliosis, tendon retractions in limbs with a semi-flexion attitude. In addition, she presented a deformity of the forefoot with hallux valgus and a triangular shape.

X-ray of the right arm showed ossification of the biceps brachii and that of the foot showed interphalangeal ankyloses with agenesis of a phalanx of the big toe. X-rays of the cervical spine revealed posterior arch ankyloses with fusion of some vertebrae. Despite the late onset of symptoms, the diagnosis of MM was suggested and confirmed by a genetic study which revealed a heterozygous c.617G> A [p. Arg206His] mutation, located in exon 6 of the gene.

Conclusion

MM is an extremely rare but disabling condition. It should be considered in unexplained muscle enlargement occurring at any age particularly if associated with congenital malformations of the Hallux. The discovery of the ACVR1 gene mutation offers hope for the development of therapies for this hitherto incurable disease.
Colombia
Authors: Mahoney Richard
                    D.
Published: November 2021

Even to experts,
Colombia is one of the most confusing countries in the Americas. Its democratic
tradition is among the richest and most long-standing in the hemisphere, with
only eleven years of military rule during its 200 some years of independence.
Except for the United States and Canada, Colombia has had the highest growth
rate in the Americas over the last 75 years. It is widely seen as having some of
the continent's best universities and deep intellectual traditions along with a
dazzling array of fine and industrial arts and now globally-popular tropical
music. But despite these admirable achievements, Colombia has also experienced
what its Nobel laureate Gabriel García Marquez once called “a biblical
holocaust” of human savagery. Along with the scourge of politically-motivated
assassinations (averaging 30 per day in the 1990s) have been drug-related
massacres, widespread disappearances, rapes and kidnappings, and even the
signature defilement of murder victims. The relentless dynamics of the illegal
drug industry raises a puzzling question: how did Colombia capture and control
that enormously-lucrative industry and then leverage its status as America's No.
1 drug supplier into a $7 billion military partnership with the world's
superpower? The answer to that question is something everyone needs to know. To
unravel the enigma, Richard D. Mahoney links historical legacies with key
periods in the post-World War II era and then sets forth overarching cultural
features--land violence, the Church, race, the Spanish language, and magical
culture-that run through Colombia’s history, distinguish its national
experience, and fuel its unquenchable creativity.
Optimization of Adipose Tissue Cryopreservation Techniques in a Murine Model
Authors: Villaverde-Doménech María Eloísa , Moltó-García Roberto , Gonzalez-Alonso Virina , Aracil-Kessler Juan Pablo , Carda-Batalla Carmen , Novella-Maestre Edurne
Published: November 2021

Background:

The aim of this study was to develop an adipose tissue (AT) cryopreservation protocol that is effective, simple, and maintains the functionality and viability of AT after thawing and transplantation.

Methods:

Two cryopreservation temperatures (T°), −20°C and −80°C, and two cryoprotective agents (CPAs), trehalose and hydroxyethyl starch (HES), were compared first in an experimental study, using a slowfreezing protocol. The five experimental groups were the following: (a) Fresh AT (control group), (b) T = −20°C, 10%HES, (c) T = −80°C, 10%HES, (d) T = −20°C, 0.35M trehalose, (e) T = −80°C, 0.35M trehalose. We evaluated the morphology (histological studies) and tissue viability by glyceraldehyde 3-phosphate dehydrogenase (GAPDH) genic expression. Based on the results of the preliminary study, an in vivo study was performed, choosing as cryopreservation T° −20°C. HES and trehalose were compared as cryoprotective agents and with a control group (fresh AT). AT grafts were transplanted into immunodeficient mice. After 1 month of inoculation, animals were euthanized and samples were recovered. Samples were weighted and processed for histological study, viability study (GAPDH genic expression), and vascularization study (VEGF genic expression).

Results:

The initial histological study demonstrated that all AT cryopreserved group samples showed typical histological features of AT, similar to that of the control group. Statistically significant differences were not observed (P > 0.05) in GAPDH expression between different groups related to temperature or CPA. Referring to the in vivo studies, cryopreserved groups showed good take of the graft and normal AT architectural preservation, as well as a clear vascular network. Statistically significant differences were not found (P > 0.05) with regard to graft take (%), GAPDH, or VEGF expression.

Conclusion:

Slow freezing at −20°C using trehalose, and −20°C using HES as cryoprotective agents are both straightforward and easy AT cryopreservation procedures, with results similar to those of fresh AT in terms of tissue viability and morphohistological characteristics.
Implications of Diagnostic Drops on Scheimpflug Tomography: The Proper Order for Clinical Testing
Authors: Padmanabhan Prema , Belin Michael W. , Sudhir Rachapalle Reddi , Mukundan Deepa , Chidambaram Hemalatha , Ambrósio Renato
Published: November 2021

Purpose:

The purpose of this article was to study the impact of instillation of 1% fluorescein and mydriatics on measurements made by Scheimpflug imaging.

Methods:

This was a cross-sectional study of patients who had measurements of corneal shape (maximum keratometry and best fit sphere of anterior and posterior corneal surfaces), pachymetry (at the pupil center, corneal apex, and thinnest location), and anterior chamber parameters (depth, volume, and angle of anterior chamber and corneal volume) using the Pentacam HR before and after the instillation of fluorescein and mydriatics. Group A had baseline measurements that were repeated 1.5 hours after the instillation of 1% fluorescein and 0.8% tropicamide+ 5% phenylephrine eye drops. Group B had baseline measurements that were repeated 10 minutes after the instillation of 1% fluorescein, and group C had baseline measurements that were repeated 1.5 hours after the instillation of mydriatics.

Results:

Overall, 131 eyes of 131 patients were studied: 87 in group A, 28 in group B, and 16 in group C. Significant differences and wide variations were noted in corneal pachymetry and anterior chamber parameters in all 3 groups. The highest magnitude and range of difference was observed in pachymetry at the pupil center (17 ± 53.5 μm) and in anterior chamber volume (26.7 ± 69.8 mm3). Corneal shape measurements of anterior and posterior corneal surfaces were not significantly affected by either fluorescein or mydriatics. Pupillary dilation also affected the ability of the Pentacam to accurately trace the pupil margin in 19.5% of cases.

Conclusions:

For consistent and accurate measurements, it is important that Scheimpflug imaging be performed before other tests which may need the instillation of fluorescein or mydriatics.
Safety and importance of colonoscopy in nonagenarians
Authors: Sung Kuan-I , Wang Yen-Po , Chang Tien-En , Wang Huann-Sheng , Jiang Jeng-Kai , Luo Jiing-Chyuan , Lee Fa-Yauh , Hou Ming-Chih , Lu Ching-Liang
Published: November 2021

Background:

With the growth of the aging population, the need for colonoscopies in nonagenarians is rising. However, few data on colonoscopies in extremely elderly individuals are available. To better acknowledge the role of colonoscopies in this specific group of patients, we conducted this study to evaluate the safety and clinical impact of colonoscopy in nonagenarian patients.

Methods:

We performed a retrospective cohort study comparing nonagenarians who received colonoscopy in a tertiary medical center in Taiwan in 2016 with 76- to 80-year-old patients (relatively elderly patients) who were 1:1 propensity score matched by sex as the control subjects. The postcolonoscopy 30-day adverse events, mortality, and long-term survival were recorded.

Results:

A total of 137 nonagenarians and 137 relatively elderly patients were included. The nonagenarians receiving colonoscopy were more likely to be hospitalized (40.1% vs 19.7%, p < 0.001), and the adjusted colonoscopy completion rates were comparable in both groups (92.0% vs 97.1%, p = 0.063). The overall adverse event rate and postcolonoscopy 30-day mortality rates were low in both groups (2.9% vs 1.5%, p = 0.409 and 2.2% vs 1.5%, p = 0.652, respectively). A total of 18.2% of the nonagenarians were diagnosed with advanced neoplasia. Among the nonagenarians diagnosed with colorectal cancer, the patients receiving surgery had a significantly lower risk of death than the patients receiving conservative management (hazards ratio 0.1044, 0.01275–0.8529, p = 0.0352).

Conclusion:

Colonoscopy in patients older than 90 years is generally safe. Colonoscopy findings that led to surgery in nonagenarians diagnosed with colorectal cancer were associated with survival benefits.
Third-Generation Dual-Source Computed Tomography for Coronary Angiography With Individually Tailored Scan Protocols Can Achieve a Low Radiation Dose With Good Image Quality in Unselected Patients
Authors: Basar Yeliz , Akbas Tugana , Alis Deniz , Ulus Sila , Topel Cagdas , Tekcan Sanli Deniz Esin , Karaarslan Ercan
Published: November 2021

Objective

To explore the image quality and radiation exposure associated with coronary angiography obtained with a third-generation dual-source computed tomography, using body mass index (BMI)– and heart rate (HR)–adapted protocols in real-world patients.

Methods

Three scan protocols were implemented with regard to HR: prospective turbo high-pitch spiral, sequential, and retrospective spiral modes. We adapted the reference kilovoltage value according to BMI. Image quality was evaluated using a 4-point scale, and effective dose estimates were calculated using the dose-length product.

Results

Among the 896 patients, 417 (46.54%), 433 (48.32%), and 45 (5.02%) were imaged using prospective turbo high-pitch spiral, sequential, and retrospective spiral modes, respectively. The median BMI was 27.3 (25–30.4) kg/m2, and the effective dose was 0.65 mSv (interquartile range, 0.33–1.56 mSv). Only 32 of 896 examinations (3.5%) had poor image quality.

Conclusions

Computed tomography angiography with BMI- and HR-tailored protocols offers good image quality with low radiation dose in unselected patients.
Impact of Sublingual Nitroglycerin on the Assessment of Computed Tomography–derived Fractional Flow Reserve: An Intraindividual Comparison Study
Authors: Gao Yifeng , Wang Wenjing , Wang Hongwei , Zhou Zhen , Xu Pengpeng , Jiang Mengdi , Yang Lin , Wang Hui , Wen Hui , Sun Zhonghua , Leipsic Jonathon A. , Zhang Longjiang , Xu Lei
Published: November 2021

Objective

The aim of this study was to investigate the impact of nitroglycerin (NTG) on the assessment of computed tomography–derived fractional flow reserve (CT-FFR).

Materials and Methods

Seventy-seven patients with suspected coronary artery disease were recruited, and they underwent computed tomography angiography (CCTA) before and after NTG administration. The CT-FFRs were compared at 2 CCTAs. The difference was compared using the Wilcoxon signed rank test. Patients were divided into normal and stenosis groups according to CCTA results. Vessels in the stenosis group were further divided into different groups based on coronary artery calcium score (CACS) and stenosis degree. The poststenotic CT-FFR differences before and after NTG (DCT-FFR) were calculated to evaluate the impact of stenosis degree and CACS. Terminal CT-FFRs derived from CCTAs before and after NTG in total and vessel-specific levels were compared in the normal group.

Results

Of 47 patients in the stenosis group, poststenotic CT-FFR was significantly increased after NTG at per-vessel level. By taking CT-FFR of 0.75 or lower as the threshold, 5 and 4 patients showed abnormal CT-FFR before and after NTG, respectively. No significant differences were noted among the various stenosis degree and CACS groups regarding DCT-FFR. Of 30 patients in the normal group, terminal CT-FFR was significantly increased after NTG in total level and vessel-specific level of left anterior descending and right coronary artery, but not in the left circumflex.

Conclusions

Both post lesion and distal vessel CT-FFR significantly improved after the administration of GTN with the degree of change not affected by stenosis severity or CACS.
Spindle Cell Carcinoma of the Breast: Investigation of Magnetic Resonance Imaging Features of 26 Cases
Authors: Tokuda Yukiko , Ko Eun Sook , Yanagawa Masahiro , Honma Keiichiro , Shimazu Kenzo , Tomiyama Noriyuki
Published: November 2021

Objective

The aim of the study was to retrospectively investigate the fat-saturated T2-weighted sequences (FST2WI) and 3-dimensional dynamic contrast-enhanced sequence (DCE) of magnetic resonance imaging (MRI) findings of breast spindle cell carcinoma (SpCC).

Methods

Twenty-six women with surgically confirmed breast SpCC, who underwent breast MRI in 2 institutions, were enrolled in this study (mean age, 54 years; range, 27–81 years). Two breast radiologists determined the MRI findings by consensus after independent interpretations. Each MRI finding was analyzed.

Results

Most lesions of SpCC showed a solitary mass (92.2%). Most masses were round/oval (76.0%), had an irregular margin (88.0%), rim enhancement (72.0%), washout kinetic analysis (96.0%), hyperintensity on FST2WI (84%), hyperintensity on FST2WI and fast enhancing component on DCE (56%), and hypointense rim on FST2WI (72.0%).

Conclusions

Most breast SpCC showed a solitary mass, round/oval shape, irregular margin, rim enhancement, washout kinetics, and intratumoral hyperintensity on FST2WI; a hypointense rim on FST2WI; and hyperintensity on FST2WI and fast enhancing component on DCE.
Comparison of 100-Kilovoltage Tin Filtration With Advanced Modeled Iterative Reconstruction Protocol to an Automated Kilovoltage Selection With Filtered Back Projection Protocol on Radiation Dose and Image Quality in Pediatric Noncontrast-Enhanced Chest Computed Tomography
Authors: Siegel Marilyn J. , Raptis Demetrios , Bhalla Sanjeev , Ramirez-Giraldo Juan Carlos
Published: November 2021

Objective

The aim of the study was to compare effects of a 100-kilovoltage (kVp) tin filtration (Sn100kVp) with Advanced Modeled Iterative Reconstruction (ADMIRE) protocol to an automated kVp selection and filtered back projection (FBP) protocol on radiation dose and image quality of in noncontrast-enhanced pediatric chest computed tomography (CT).

Methods

This retrospective study included 55 children (12 ± 6 years) undergoing baseline imaging using automated kVp selection with FBP on a second-generation dual-source CT scanner and follow-up CT using Sn100kVp with ADMIRE on a third-generation dual-source CT scanner. The volume CT dose index, dose length product, size-specific dose estimate, and milliamperage were compared. Image quality was calculated using signal-to-noise ratio and subjectively evaluated by 2 radiologists.

Results

Mean volume CT dose index, dose length product, and size-specific dose estimate were lower for the Sn100kVp protocol with ADMIRE (0.83 ± 0.18 mGy, 21.9 ± 7.5 mGy × cm, 1.28 ± 0.24 mGy) compared with the automated kVp protocol with FBP (2.17 ± 1.10 mGy, 65.1 ± 41.1 mGy × cm, 3.25 ± 1.44 mGy, P < 0.001), whereas milliamperage was and subjective image quality were higher for Sn100kVp (P < 0.001).

Conclusions

A Sn100kVp protocol with ADMIRE lowers dose while maintaining image quality in noncontrast-enhanced pediatric chest CT.
Virtual Noncontrast Images Derived From Contrast-Enhanced Dual-Layer Spectral Abdominal Computed Tomography: A Pilot Study Between Pediatric and Adult Scans
Authors: Azuma Minako , Nakada Hiroshi , Khant Zaw Aung , Kimura Aya , Hirai Toshinori
Published: November 2021

Objective

We aimed to compare the accuracy of virtual noncontrast (VNC) images obtained from contrast-enhanced dual-layer spectral computed tomography (DLSCT) scans of the abdomen between pediatric and adult patients.

Methods

We retrospectively studied 10 pediatric and 40 adult patients who underwent unenhanced and contrast-enhanced DLSCT for nontraumatic acute abdomen or a follow-up of tumor or aneurysm. On true noncontrast (TNC) and VNC images, we placed a region-of-interest on 7 abdominal structures. The mean attenuation difference between VNC and TNC images was compared between these structures and between pediatric and adult scans. Data were analyzed by using the Wilcoxon signed-rank test, 1-way analysis of variance, Scheffe's test and independent t test. A P value less than 0.05 was considered statistically significant.

Results

In mean attenuation difference between VNC and TNC images, there was a significant interstructure difference in adult scans (P < 0.05), but not in pediatric scans. Mean attenuation difference between VNC and TNC images of the kidney was significantly higher on adult than pediatric scans (P = 0.0046).

Conclusions

The VNC images obtained from contrast-enhanced DLSCT data may be more accurate on pediatric than adult scans. Patient age can be a factor influencing the accuracy of the VNC images.
Wickerhamiella martinezcruziae f. a., sp. nov., a yeast species isolated from tropical habitats
Authors: Maciel Natália O. P. , Santos Ana R. O. , Felix Ciro R. , Landell Melissa F. , Pagani Danielle M. , Pimenta Raphael S. , Morais Paula B. , Angchuan Jirameth , Wongpanit Kannika , Srisuk Nantana , Lachance Marc-André , Rosa Carlos A.
Published: November 2021

Four yeast isolates with an affinity to the genus Wickerhamiella were obtained from beach sand, a marine zoanthid and a tree exudate at different localities in Brazil. Two other isolates with almost identical ITS and D1/D2 sequences of the large subunit rRNA gene were isolated from the small intestine of cattle and a grease trap in Thailand. These isolates represent a novel species phylogenetically related to Wickerhamiella verensis, Wickerhamiella osmotolerans, Wickerhamiella tropicalis, Wickerhamiella sorbophila and Wickerhamiella infanticola. The novel species differs by 15–30 nucleotide differences from these species in the D1/D2 sequences. The name Wickerhamiella martinezcruziae f.a., sp. nov. is proposed. The holotype of Wickerhamiella martinezcruziae sp. nov. is CBS 16104T. The MycoBank number is MB 839328.
Brevibacillus composti sp. nov., isolated from hyperthermophilic compost
Authors: Tang Rong , Zhang Qi , Ye Yin , Yang Shang , Fu Tao , Liu Guo-Hong , Zhou Shun-Gui
Published: November 2021

Two aerobic, Gram-stain-positive, rod-shaped, endospore-forming, thermophilic bacterial strains, designated FJAT-54423T and FJAT-54424, were isolated from hyperthermophilic compost sampled in Shanxi Province, PR China. Growth was observed at 30–60 °C (optimum, 50 °C) and pH 6.0–9.0 (optimum, pH 7.0), with up to 2.0 % (w/v) NaCl (optimum, 0 % NaCl). The 16S rRNA gene sequence similarity between FJAT-54423T and FJAT-54424 was 99.9%, and the maximum similarity to a valid taxon was observed with

Brevibacillus borstelensis

(98.3%). Further, in phylogenetic and phylogenomic trees, strains FJAT-54423T and FJAT-54424 branched with members of the genus

Brevibacillus

. The menaquinone was MK-7, and the major fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The main polar lipids included phosphatidylmethylethanolamine, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The cell-wall peptidoglycan was found to contain meso-diaminopimelic acid. The DNA G+C content of strains FJAT-54423T and FJAT-54424 were 54.3 and 54.4 mol%, respectively. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values of strain FJAT-54423T and its most closely related reference strain

B. borstelensis

DSM 6347T were 77.7 and 21.5 %, respectively, which were lower than the recommended species delineation thresholds of ANI (95%) and dDDH (70%). Based on the observed physiological properties, chemotaxonomic characteristics and ANI and dDDH values, FJAT-54423T and FJAT-54424 belong to a novel species of the genus

Brevibacillus

, for which the name Brevibacillus composti sp. nov. is proposed. The type strain is FJAT-54423T (=GDMCC 1.2054T=KCTC 43273T).
A prototype vaccination model for endemic Covid-19 under waning immunity and imperfect vaccine take-up
Authors: Dagpunar John , Wu Chenchen
Published: November 2021

In this paper, for an infectious disease such as Covid-19, we present a SIR model which examines the impact of waning immunity, vaccination rates, vaccine efficacy, and the proportion of the susceptible population who aspire to be vaccinated. Under an assumed constant control reproduction number, we provide simple conditions for the disease to be eliminated, and conversely for it to exhibit the more likely endemic behaviour. With regard to Covid-19, it is shown that if the control reproduction number is set to the basic reproduction number (say 6) of the dominant delta (B1.617.2) variant, vaccination alone, even under the most optimistic of assumptions about vaccine efficacy and high vaccine coverage, is very unlikely to lead to elimination of the disease. The model is not intended to be predictive but more an aid to understanding the relative importance of various biological and control parameters. For example, from a long-term perspective, it may be found that in the UK, through changes in societal behaviour (such as mask use, ventilation, and level of homeworking), without formal government interventions such as on-off lockdowns, the control reproduction number can still be maintained at a level significantly below the basic reproduction number. Even so, our simulations show that endemic behaviour ensues. The model obtains equilibrium values of the state variables such as the infection prevalence and mortality rate under various scenarios.
High-resolution ultrasonography of gingival biomarkers for periodontal diagnosis in healthy and diseased subjects
Authors: Moore Colman , Law Jane , Pham Christopher , Joe Chang Kai Chiao , Chen Casey , Jokerst Jesse V.
Published: November 2021

Periodontal disease affects nearly 50% of Americans but diagnostic methods have remained the same for decades. Periodontal examination via physical probing provides critical metrics such as pocket depth, clinical attachment level, and gingival recession; however, this practice is time consuming, variable, and often painful. In this study, we investigated high-frequency ultrasound (40 MHz) for the image-based measurement of periodontal metrics. Imaging was performed at midbuccal sites for a set of periodontally healthy (n = 10) and diseased (n = 6) subjects and image-based measurements were compared to gold-standard physical probing measurements. Human operators identified relevant markers (e.g., cementoenamel junction, gingival margin, alveolar bone crest) in B-mode ultrasound images from 66 teeth to calculate gingival height and alveolar bone level. These metrics were correlated to clinical measurements of probing pocket depth and clinical attachment level for disease staging (1.57-mm bias and 0.25-mm bias, respectively). Interoperator bias was negligible (<0.1 mm) for gingival height measurements and 0.45 mm for alveolar bone level measurements. The ultrasonographic measurements of gingival height and alveolar bone level served as effective diagnostic surrogates for clinical probing measurements while offering more detailed anatomical information and painless operation.
Tropical forest dynamics correspond to fair games in economic theory of financial markets
Authors: Lin Yue , Rosindell James , Berger Uta , Bruelheide Helge , Kattge Jens , Grimm Volker
Published: November 2021

Ecological and economic systems both comprise of autonomous adaptive agents. It is thus possible that similar mechanisms determine the organization of both these complex systems. Indeed several economic theories have already been successfully applied in an ecological context. Here we show that ‘efficient market theory’ in economics, where future earnings are distributed between competitors by a ‘fair game’, corresponds to fitness-equalizing mechanisms of coexistence in ecology. In contrast to stabilizing mechanisms, which promote coexistence by giving each species an equilibrium abundance that is resilient to perturbations, equalizing mechanisms promote coexistence without such resilience by minimizing the net fitness differences between species. However, identifying stabilizing and equalizing mechanisms from the short time-series data that are typically available in ecology is challenging. We used techniques from economics that are applied to collections of short time-series from a system. We found that observed species abundance dynamics in a neotropical forest are generally in agreement with efficient market theory implying a dominant role of equalizing mechanisms, which finding quantifies and supports what was generally believed about that specific forest system. Our study highlights that complex systems from ecology and economics share common features suggesting the possibility of further synergy between ecology and economics in future.
SHP2 promotes NETosis through ERK5 pathway and mediates the development of psoriasis
Authors: Ding Yan , Qu Jiao , Zhang Chenyang , Zhu Yuyu , Xu Qiang , Sun Yang
Published: November 2021

Psoriasis is a chronic inflammatory disease which infiltrated a large number of neutrophils among skin lesions. Here, we investigated the contribution of tyrosine phosphatase SHP2 in neutrophils, as well as it’s pathogenesis in psoriasis. We combined single-cell RNA sequencing with experimental verification to declare that SHP2 in neutrophils could promote the NETs formation through the ERK5 pathway, and resulted in the infiltration of inflammatory immune cells, which leads to psoriasis. Our study provides evidence for the role of SHP2 in NETosis in the progression of psoriasis, and SHP2 may be a potential therapeutic target for the treatment of psoriasis.
Rapid antibiotic susceptibility testing and species identification for mixed infections
Authors: Kandavalli Vinodh , Karempudi Praneeth , Larsson Jimmy , Elf Johan
Published: November 2021

Antimicrobial resistance is an increasing problem globally. Rapid antibiotic susceptibility testing (AST) is urgently needed in the clinic to enable personalized prescription in high-resistance environments and limit the use of broad-spectrum drugs. Previously we have described a 30 min AST method based on imaging of individual bacterial cells. However, current phenotypic AST methods do not include species identification (ID), leaving time-consuming plating or culturing as the only available option when ID is needed to make the sensitivity call. Here we describe a method to perform phenotypic AST at the single-cell level in a microfluidic chip that allows subsequent genotyping by in situ FISH. By stratifying the phenotypic AST response on the species of individual cells, it is possible to determine the susceptibility profile for each species in a mixed infection sample in 1.5 h. In this proof-of-principle study, we demonstrate the operation with four antibiotics and a mixed sample with four species.
Metamorphosis of the Mushroom Bodies; Large-Scale Rearrangements of the Neural Substrates for Associative Learning and Memory in Drosophila
Authors: Armstrong J. Douglas , de Belle J. Steven , Wang Zongsheng , Kaiser Kim
Published: November 2021

Paired brain centers known as mushroom bodies are key features of the circuitry for insect associative learning, especially when evoked by olfactory cues. Mushroom bodies have an embryonic origin, and unlike most other brain structures they exhibit developmental continuity, being prominent components of both the larval and the adult CNS. Here, we use cell-type-specific markers, provided by the P{GAL4} enhancer trap system, to follow specific subsets of mushroom body intrinsic and extrinsic neurons from the larval to the adult stage. We find marked structural differences between the larval and adult mushroom bodies, arising as the consequence of large-scale reorganization during metamorphosis. Extensive, though incomplete, degradation of the larval structure is followed by establishment of adult specific α and β lobes. Kenyon cells of embryonic origin, by contrast, were found to project selectively to the adult γ lobe. We propose that the γ lobe stores information of relevance to both developmental stages, whereas the α and β lobes have uniquely adult roles.
Evolution, Discovery, and Interpretations of Arthropod Mushroom Bodies
Authors: Strausfeld Nicholas J. , Hansen Lars , Li Yongsheng , Gomez Robert S. , Ito Kei
Published: November 2021

Mushroom bodies are prominent neuropils found in annelids and in all arthropod groups except crustaceans. First explicitly identified in 1850, the mushroom bodies differ in size and complexity between taxa, as well as between different castes of a single species of social insect. These differences led some early biologists to suggest that the mushroom bodies endow an arthropod with intelligence or the ability to execute voluntary actions, as opposed to innate behaviors. Recent physiological studies and mutant analyses have led to divergent interpretations. One interpretation is that the mushroom bodies conditionally relay to higher protocerebral centers information about sensory stimuli and the context in which they occur. Another interpretation is that they play a central role in learning and memory. Anatomical studies suggest that arthropod mushroom bodies are predominately associated with olfactory pathways except in phylogenetically basal insects. The prominent olfactory input to the mushroom body calyces in more recent insect orders is an acquired character. An overview of the history of research on the mushroom bodies, as well as comparative and evolutionary considerations, provides a conceptual framework for discussing the roles of these neuropils.
Multiple Sites of Associative Odor Learning as Revealed by Local Brain Microinjections of Octopamine in Honeybees
Authors: Hammer Martin , Menzel Randolf
Published: November 2021

In a classical conditioning procedure, honeybees associate an odor with sucrose resulting in the capacity of the odor to evoke an appetitive response, the extension of the proboscis (PER). Here, we study the effects of pairing an odor with injections of octopamine (OA) as a substitute for sucrose into three putative brain sites of odor/sucrose convergence. OA injected into the mushroom body (MB) calyces or the antennal lobe but not the lateral protocerebral lobe produces a lasting, pairing-specific enhancement of PER. During pairings, OA injected into the MB calyces results in an additional pairing-specific effect, because it does not lead to an acquisition but a consolidation after conditioning. These results suggest that the neuromodulator OA has the capacity of inducing associative learning in an insect brain. Moreover, they suggest the antennal lobes and the calyces as at least partially independent sites of associating odors that may contribute differently to learning and memory consolidation.
Dopamine and Mushroom Bodies in Drosophila: Experience-Dependent and -Independent Aspects of Sexual Behavior
Authors: Neckameyer Wendi S.
Published: November 2021

Depletion of dopamine in Drosophila melanogaster adult males, accomplished through systemic introduction of the tyrosine hydroxylase inhibitor 3-iodo-tyrosine, severely impaired the ability of these flies to modify their courtship responses to immature males. Mature males, when first exposed to immature males, will perform courtship rituals; the intensity and duration of this behavior rapidly diminshes with time. Dopamine is also required for normal female sexual receptivity; dopamine-depleted females show increased latency to copulation. One kilobase of 5′ upstream information from theDrosophila tyrosine hydroxylase (DTH) gene, when fused to theEscherichia coli β-galactosidase reporter and transduced into the genome of Drosophila melanogaster, is capable of directing expression of the reporter gene in the mushroom bodies, which are believed to mediate learning acquisition and memory retention in flies. Ablation of mushroom bodies by treatment of newly hatched larva with hydroxyurea resulted in the inability of treated mature adult males to cease courtship when placed with untreated immature males. However, functional mushroom bodies were not required for the dopaminergic modulation of an innate behavior, female sexual receptivity. These data suggest that dopamine acts as a signaling molecule within the mushroom bodies to mediate a simple form of learning.
Multiple Memory Processes Following Training That a Food Is Inedible in Aplysia
Authors: Botzer Dina , Markovich Silvia , Susswein Abraham J.
Published: November 2021

In many organisms, memory after training can be separated into a number of processes. We now report that separable memory processes are also initiated by a training procedure affectingAplysia feeding behavior, a model system for examining the neural mechanisms underlying the regulation of a complex behavior. Four distinct memory process were identified: (1) a very short-term memory that declines within 15 min, (2) a short-term memory that persists for 0.5–1.0 hr, (3) an intermediate-term memory, observed 4 hr after training, and (4) a long-term memory that is seen only after a 12- to 24-hr delay. The four memory processes can be distinguished by the different training procedures that are required to elicit them. A single 5-min training session is sufficient to elicit the very short-term memory. However, a longer training session that continues until the animal stops responding to food is needed to elicit short-term memory. Intermediate-term memory is observed only after a spaced training procedure (three 5-min training sessions separated by 30-min intervals). A single 5-min training session that does not cause either short-term or intermediate-term memory is sufficient to induce long-term memory, indicating that short- and long-term memory are independent, parallel processes. Short- and long-term memory can also be separated by the effects of a post-training experience. Long-term, but not short-term, memory can be attenuated by cooling animals immediately after training. Cooling before the training does not affect either the training or the subsequent short- or long-term memory.
The Specific Role of cGMP in Hippocampal LTP
Authors: Son Hyeon , Lu Yun-Fei , Zhuo Min , Arancio Ottavio , Kandel Eric R. , Hawkins Robert D.
Published: November 2021

Previous results have suggested that cGMP is involved in hippocampal long-term potentiation (LTP), perhaps as the presynaptic effector of a retrograde messenger. However, other studies have failed to replicate some of those results, making the role of cGMP uncertain. We therefore reexamined this question and identified several variables that can affect the contribution of cGMP. First, brief perfusion with 8-Br–cGMP before weak tetanic stimulation produced long-lasting potentiation in the CA1 region of hippocampal slices, but more prolonged perfusion with 8-Br–cGMP before the tetanus did not produce long-lasting potentiation. Second, the activity-dependent long-lasting potentiation by cGMP analogs was reduced when NMDA receptors were completely blocked, indicating that NMDA receptor activation contributes to, but is not required for, the potentiation. The amount of reduction of the potentiation differed with different protocols, and in some cases could be complete. Third, LTP produced by strong tetanic stimulation in the stratum radiatum of CA1 (which expresses eNOS) was blocked by inhibitors of soluble guanylyl cyclase or cGMP-dependent protein kinase, but LTP in the stratum oriens (which does not express eNOS) was not. The results of these experiments should help to explain some of the discrepant findings from previous studies, and, in addition, may provide insights into the mechanisms and functional role of the cGMP-dependent component of LTP.
Selective Abolition of the NMDA Component of Long-Term Potentiation in Mice Lacking mGluR5
Authors: Jia Zhengping , Lu YouMing , Henderson Jeff , Taverna Franco , Romano Carmelo , Abramow-Newerly Wanda , Wojtowicz J. Martin , Roder John
Published: November 2021

The mechanisms underlying the differential expression of long-term potentiation (LTP) by AMPA and NMDA receptors, are unknown, but could involve G-protein-linked metabotropic glutamate receptors. To investigate this hypothesis we created mutant mice that expressed no metabotropic glutamate receptor 5 (mGluR5), but showed normal development. In an earlier study of these mice we analyzed field-excitatory postsynaptic potential (fEPSPs) in CA1 region of the hippocampus and found a small decrease; possibly arising from changes in the NMDAR-mediated component of synaptic transmission. In the present study we used whole-cell patch clamp recordings of evoked excitatory postsynaptic currents (EPSCs) in CA1 pyramidal neurons to identify the AMPAR- and NMDAR-mediated components of LTP. Recordings from control mice following tetanus, or agonist application (IS, 3R-1-amino-cyclopentane 1,3-dicarboxylic acid) (ACPD), revealed equal enhancement of the AMPA and NMDA receptor-mediated components. In contrast, CA1 neurons from mGluR5-deficient mice showed a complete loss of the NMDA-receptor-mediated component of LTP (LTPNMDA), but normal LTP of the AMPA-receptor-mediated component (LTPAMPA). This selective loss of LTPNMDA was seen in three different genotypic backgrounds and was apparent at all holding potentials (−70 mV to +20 mV). Furthermore, the LTPNMDA deficit in mGluR5 mutant mice could be rescued by stimulating protein kinase C (PKC) with 4β-phorbol-12,13-dibutyrate (PDBu). These results suggest that PKC may couple the postsynaptic mGluR5 to the NMDA-receptor potentiation during LTP, and that this signaling mechanism is distinct from LTPAMPA. Differential enhancement of AMPAR and NMDA receptors by mGluR5 also supports a postsynaptic locus for LTP.
Separate Effects of a Classical Conditioning Procedure on Respiratory Pumping, Swimming, and Inking inAplysia fasciata
Authors: Levy Miriam , Susswein Abraham J.
Published: November 2021

We examined whether swimming and inking, two defensive responses inAplysia fasciata, are facilitated by a classical conditioning procedure that has been shown to facilitate a third defensive response, respiratory pumping. Training consisted of pairing a head shock (UCS) with a modified seawater (85%, 120%, or pH 7.0 seawater—CSs). Animals were tested by re-exposing them to the same altered seawater 1 hr after the training. For all three altered seawaters, only respiratory pumping is specifically increased by conditioning. Swimming is sensitized by shock, and inking is unaffected by training, indicating that the conditioning procedure is likely to affect a neural site that differentially controls respiratory pumping. Additional observations also indicate that the three defensive responses are differentially regulated. First, different noxious stimuli preferentially elicit different defensive responses. Second, the three defensive responses are differentially affected by shock. Inking is elicited only immediately following shock, whereas swimming and respiratory pumping are facilitated for a period of time following the shock. Third, swimming and respiratory pumping are differentially affected by noxious stimuli that are delivered in open versus closed environments. These data confirm that neural pathways exist that allowAplysiato modulate separately each of the three defensive behaviors that were examined.
Prism Adaptation and Aftereffect: Specifying the Properties of a Procedural Memory System
Authors: Fernández-Ruiz Juan , Díaz Rosalinda
Published: November 2021

Prism adaptation, a form of procedural learning, is a phenomenon in which the motor system adapts to new visuospatial coordinates imposed by prisms that displace the visual field. Once the prisms are withdrawn, the degree and strength of the adaptation can be measured by the spatial deviation of the motor actions in the direction opposite to the visual displacement imposed by the prisms, a phenomenon known as aftereffect. This study was designed to define the variables that affect the acquisition and retention of the aftereffect. Subjects were required to throw balls to a target in front of them before, during, and after lateral displacement of the visual field with prismatic spectacles. The diopters of the prisms and the number of throws were varied among different groups of subjects. The results show that the adaptation process is dependent on the number of interactions between the visual and motor system, and not on the time spent wearing the prisms. The results also show that the magnitude of the aftereffect is highly correlated with the magnitude of the adaptation, regardless of the diopters of the prisms or the number of throws. Finally, the results suggest that persistence of the aftereffect depends on the number of throws after the adaptation is complete. On the basis of these results, we propose that the system underlying this kind of learning stores at least two different parameters, the contents (measured as the magnitude of displacement) and the persistence (measured as the number of throws to return to the baseline) of the learned information.
Sequence-Specific Impairment of Memory Formation by NCAM Antisense Oligonucleotides
Authors: Mileusnic Radmila , Lancashire Christine , Rose Steven P.R.
Published: November 2021

The functional role of NCAM gene expression in memory formation was studied in the one-trial passive avoidance task in day-old chicks by pretraining injections of one of three different 18-mer end-protected oligonucleotides corresponding to positions 190-, 207-, and 332- of the NCAM Ig1 domain. Twenty-four-hour-old chicks were trained by pecking at a bitter-tasting bead and tested for avoidance 30 min, 3, 8, or 24 hr later. Memory retention was significantly reduced only in the group of animals injected with the NCAM antisense corresponding to position 207- (AS-ODN-207), and only if given twice, both immediately after hatching and 12 hr before training. This antisense was without effect on the general behavior of the chicks, training or acquisition, and did not produce observable neurotoxic damage. Under such conditions amnesia was evident by 3 hr after training and lasted until at least 24 hr after training. The two other tested oligonucleotides were without behavioral effect. To control for nonsequence-specific effects of AS-ODN-207, brains from injected and trained animals were processed for Western blotting and probed using anti-NCAM, anti-L1, and anti-actin antibodies. NCAM antisense corresponding to position 207- significantly reduced the level of NCAM, whereas the level of L1 and actin remained unchanged. These results confirm our earlier conclusion that NCAM is necessary for longer term memory retention.
Effects of Paired and Unpaired Eye-Blink Conditioning on Purkinje Cell Morphology
Authors: Anderson Brenda J. , Relucio Karen , Haglund Karl , Logan Christy , Knowlton Barbara , Thompson Judith , Steinmetz Joseph E. , Thompson Richard F. , Greenough William T.
Published: November 2021

This experiment addressed (1) the importance of conjunctive stimulus presentation for morphological plasticity of cerebellar Purkinje cells and inhibitory interneurons and (2) whether plasticity is restricted to the spiny branches of Purkinje cells, which receive parallel fiber input. These issues were investigated in naive rabbits and in rabbits that received paired or unpaired presentations of the conditioned stimulus (CS) and unconditioned stimulus (US). To direct CS input to the cerebellar cortex, pontine stimulation served as the CS. Air puffs to the cornea served as the US. Paired condition rabbits received pontine stimulation for 350 msec paired with a coterminating 100-msec air puff. Unpaired condition rabbits received the same stimuli in a pseudorandom order at 1- to 32-sec intervals. Rabbits were trained for a mean of 12 days. Naive rabbits received no treatment. In Golgi-stained Purkinje neurons in lobule HVI, total dendritic length, main branch length, total spiny branch length, and number of spiny branch arbors were all greater in the naive group than in the paired and unpaired groups, which did not differ. No differences were found between the hemispheres ipsilateral and contralateral to the trained eye. The dendritic length and number of branches for inhibitory interneurons did not differ across groups. The Purkinje cell morphological changes detected with these methods do not appear to be uniquely related to the conjunctive activation of the CS and US in the paired condition.
Regulation of Synaptic Function by Neurotrophic Factors in Vertebrates and Invertebrates: Implications for Development and Learning
Authors: McKay Sharen E. , Purcell Angela L. , Carew Thomas J.
Published: November 2021

Recent studies have demonstrated that neurotrophic factors contribute to the molecular events involved in synaptic plasticity, both during vertebrate development and in the mature nervous system. Although it is well established that many of the cellular and molecular mechanisms underlying synaptic plasticity are conserved between invertebrates and vertebrates, there are, as yet, very few neurotrophic factors identified in invertebrate species. Nonetheless, vertebrate neurotrophins can influence invertebrate neuronal growth and plasticity. In addition, homologs of neurotrophic factor receptors have been identified in several invertebrate species. These studies may indicate that the roles of neurotrophins in both developmental and adult plasticity are highly conserved across diverse phyla.
Blockade of NR2B-Containing NMDA Receptors Prevents BDNF Enhancement of Glutamatergic Transmission in Hippocampal Neurons
Authors: Crozier Robert A. , Black Ira B. , Plummer Mark R.
Published: November 2021

Application of brain-derived neurotrophic factor (BDNF) to hippocampal neurons has profound effects on glutamatergic synaptic transmission. Both pre- and postsynaptic actions have been identified that depend on the age and type of preparation. To understand the nature of this diversity, we have begun to examine the mechanisms of BDNF action in cultured dissociated embryonic hippocampal neurons. Whole-cell patch-clamp recording during iontophoretic application of glutamate revealed that BDNF doubled the amplitude of induced inward current. Coexposure to BDNF and the NMDA receptor antagonist AP-5 markedly reduced, but did not entirely prevent, the increase in current. Coexposure to BDNF and ifenprodil, an NR2B subunit antagonist, reproduced the response observed with AP-5, suggesting BDNF primarily enhanced activity of NR2B-containing NMDA receptors with a lesser effect on non-NMDA receptors. Protein kinase involvement was confirmed with the broad spectrum inhibitor staurosporine, which prevented the response to BDNF. PKCI19-31 and H-89, selective antagonists of PKC and PKA, had no effect on the response to BDNF, whereas autocamtide-2-related inhibitory peptide, an antagonist of CaM kinase II, reduced response magnitude by 60%. These results demonstrate the predominant role of a specific NMDA receptor subtype in BDNF modulation of hippocampal synaptic transmission.