Specialized connectivity of molecular layer interneuron subtypes leads to disinhibition and synchronous inhibition of cerebellar Purkinje cells

Molecular layer interneurons (MLIs) account for approximately 80% of the inhibitory interneurons in the cerebellar cortex and are vital to cerebellar processing. MLIs are thought to primarily inhibit Purkinje cells (PCs) and suppress the plasticity of synapses onto PCs. MLIs also inhibit, and are electrically coupled to, other MLIs, but the functional significance of these connections is not known. Here, we find that two recently recognized MLI subtypes, MLI1 and MLI2, have a highly specialized connectivity that allows them to serve distinct functional roles. MLI1s primarily inhibit PCs, are electrically coupled to each other, fire synchronously with other MLI1s on the millisecond timescale in vivo, and synchronously pause PC firing. MLI2s are not electrically coupled, primarily inhibit MLI1s and disinhibit PCs, and are well suited to gating cerebellar-dependent behavior and learning. The synchronous firing of electrically coupled MLI1s and disinhibition provided by MLI2s require a major re-evaluation of cerebellar processing.

Permanent deconstruction of intracellular primary cilia in differentiating granule cell neurons

Primary cilia on granule cell neuron progenitors in the developing cerebellum detect sonic hedgehog to facilitate proliferation. Following differentiation, cerebellar granule cells become the most abundant neuronal cell type in the brain. While essential during early developmental stages, the fate of granule cell cilia is unknown. Here, we provide nanoscopic resolution of ciliary dynamics in situ by studying developmental changes in granule cell cilia using large-scale electron microscopy volumes and immunostaining of mouse cerebella. We found that many granule cell primary cilia were intracellular and concealed from the external environment. Cilia were disassembed in differentiating granule cell neurons in a process we call cilia deconstruction that was distinct from pre-mitotic cilia resorption in proliferating progenitors. In differentiating granule cells, ciliary loss involved unique disassembly intermediates, and, as maturation progressed, mother centriolar docking at the plasma membrane. Cilia did not reform from the docked centrioles, rather, in adult mice granule cell neurons remained unciliated. Many neurons in other brain regions require cilia to regulate function and connectivity. In contrast, our results show that granule cell progenitors had concealed cilia that underwent deconstruction potentially to prevent mitogenic hedgehog responsiveness. The ciliary deconstruction mechanism we describe could be paradigmatic of cilia removal during differentiation in other tissues.

The impact of preoperative sarcopenia on postoperative ileus following colorectal cancer surgery

PURPOSE

Sarcopenia is associated with poor short- and long-term patient outcomes following colorectal surgery. Despite postoperative ileus (POI) being a major complication following colorectal surgery, the predictive value of sarcopenia for POI is unclear. We assessed the association between sarcopenia and POI in patients with colorectal cancer.

METHODS

Elective colorectal cancer surgery patients were retrospectively included (2018-2022). The cross-sectional psoas area was calculated using preoperative staging imaging at the level of the 3rd lumbar vertebrae. Sarcopenia was determined using gender-specific cut-offs. The primary outcome POI was defined as not achieving GI-2 by day 4. Demographics, operative characteristics, and complications were compared via univariate and multivariate analyses.

RESULTS

Of 297 patients, 67 (22.6%) were sarcopenic. Patients with sarcopenia were older (median 74 (IQR 67-82) vs. 69 (58-76) years, p < 0.001) and had lower body mass index (median 24.4 (IQR 22.2-28.6) vs. 28.8 (24.9-31.9) kg/m2, p < 0.001). POI was significantly more prevalent in patients with sarcopenia (41.8% vs. 26.5%, p = 0.016). Overall rate of complications (85.1% vs. 68.3%, p = 0.007), Calvien-Dindo grade > 3 (13.4% vs. 10.0%, p = 0.026) and length of stay were increased in patients with sarcopenia (median 7 (IQR 5-12) vs. 6 (4-8) days, p = 0.013). Anastomotic leak rate was higher in patients with sarcopenia although the difference was not statistically significant (7.5% vs. 2.6%, p = 0.064). Multivariate analysis demonstrated sarcopenia (OR 2.0, 95% CI 1.1-3.8), male sex (OR 1.9, 95% CI 1.0-3.5), postoperative hypokalemia (OR 3.2, 95% CI 1.6-6.5) and increased opioid use (OR 2.4, 95% CI 1.3-4.3) were predictive of POI.

CONCLUSION

Sarcopenia demonstrates an association with POI. Future research towards truly identifying the predictive value of sarcopenia for postoperative complications could improve informed consent and operative planning for surgical patients.

Three-dimensional reconstructions of mechanosensory end organs suggest a unifying mechanism underlying dynamic, light touch

Across mammalian skin, structurally complex and diverse mechanosensory end organs respond to mechanical stimuli and enable our perception of dynamic, light touch. How forces act on morphologically dissimilar mechanosensory end organs of the skin to gate the requisite mechanotransduction channel Piezo2 and excite mechanosensory neurons is not understood. Here, we report high-resolution reconstructions of the hair follicle lanceolate complex, Meissner corpuscle, and Pacinian corpuscle and the subcellular distribution of Piezo2 within them. Across all three end organs, Piezo2 is restricted to the sensory axon membrane, including axon protrusions that extend from the axon body. These protrusions, which are numerous and elaborate extensively within the end organs, tether the axon to resident non-neuronal cells via adherens junctions. These findings support a unified model for dynamic touch in which mechanical stimuli stretch hundreds to thousands of axon protrusions across an end organ, opening proximal, axonal Piezo2 channels and exciting the neuron.

Cerebellar circuits for disinhibition and synchronous inhibition

The cerebellar cortex contributes to diverse behaviors by transforming mossy fiber inputs into predictions in the form of Purkinje cell (PC) outputs, and then refining those predictions1. Molecular layer interneurons (MLIs) account for approximately 80% of the inhibitory interneurons in the cerebellar cortex2, and are vital to cerebellar processing1,3. MLIs are thought to primarily inhibit PCs and suppress the plasticity of excitatory synapses onto PCs. MLIs also inhibit, and are electrically coupled to, other MLIs4-7, but the functional significance of these connections is not known1,3. Behavioral studies suggest that cerebellar-dependent learning is gated by disinhibition of PCs, but the source of such disinhibition has not been identified8. Here we find that two recently recognized MLI subtypes2, MLI1 and MLI2, have highly specialized connectivity that allows them to serve very different functional roles. MLI1s primarily inhibit PCs, are electrically coupled to each other, fire synchronously with other MLI1s on the millisecond time scale in vivo, and synchronously pause PC firing. MLI2s are not electrically coupled, they primarily inhibit MLI1s and disinhibit PCs, and are well suited to gating cerebellar-dependent learning8. These findings require a major reevaluation of processing within the cerebellum in which disinhibition, a powerful circuit motif present in the cerebral cortex and elsewhere9-17, greatly increases the computational power and flexibility of the cerebellum. They also suggest that millisecond time scale synchronous firing of electrically-coupled MLI1s helps regulate the output of the cerebellar cortex by synchronously pausing PC firing, which has been shown to evoke precisely-timed firing in PC targets18.

Histological and electron microscopic features of the extracellular matrix of invasive breast ductal carcinoma of no special type. Report of 5 cases and literature review

Invasive ductal carcinoma of no special type is the most common type of breast cancer. In light of the above, many authors have reported the histological and electron microscopic characteristics of these tumors. On the other hand, a limited number of works exist where the authors have concentrated on investigating the extracellular matrix. This article presents data received as the results of light and electron microscopic examination of the extracellular matrix, angiogenesis, and cellular microenvironment of invasive breast ductal carcinoma of no special type. The authors have shown that the processes of stroma formation in the IDC NOS type are associated with the presence of fibroblasts, macrophages, dendritic cells, lymphocytes, and other cells. It was also shown the detailed interaction of the above cells with each other, as well as with vessels and fibrillar proteins such as collagen and elastin. The microcirculatory component is characterized by histophysiological heterogeneity, which manifests as the activation of angiogenesis, relative vascular differentiation, and regression of individual microcirculation components.

Three-dimensional reconstructions of mechanosensory end organs suggest a unifying mechanism underlying dynamic, light touch

Specialized mechanosensory end organs within mammalian skin-hair follicle-associated lanceolate complexes, Meissner corpuscles, and Pacinian corpuscles-enable our perception of light, dynamic touch 1 . In each of these end organs, fast-conducting mechanically sensitive neurons, called Aβ low-threshold mechanoreceptors (Aβ LTMRs), associate with resident glial cells, known as terminal Schwann cells (TSCs) or lamellar cells, to form complex axon ending structures. Lanceolate-forming and corpuscle-innervating Aβ LTMRs share a low threshold for mechanical activation, a rapidly adapting (RA) response to force indentation, and high sensitivity to dynamic stimuli 1-6 . How mechanical stimuli lead to activation of the requisite mechanotransduction channel Piezo2 7-15 and Aβ RA-LTMR excitation across the morphologically dissimilar mechanosensory end organ structures is not understood. Here, we report the precise subcellular distribution of Piezo2 and high-resolution, isotropic 3D reconstructions of all three end organs formed by Aβ RA-LTMRs determined by large volume enhanced Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) imaging. We found that within each end organ, Piezo2 is enriched along the sensory axon membrane and is minimally or not expressed in TSCs and lamellar cells. We also observed a large number of small cytoplasmic protrusions enriched along the Aβ RA-LTMR axon terminals associated with hair follicles, Meissner corpuscles, and Pacinian corpuscles. These axon protrusions reside within close proximity to axonal Piezo2, occasionally contain the channel, and often form adherens junctions with nearby non-neuronal cells. Our findings support a unified model for Aβ RA-LTMR activation in which axon protrusions anchor Aβ RA-LTMR axon terminals to specialized end organ cells, enabling mechanical stimuli to stretch the axon in hundreds to thousands of sites across an individual end organ and leading to activation of proximal Piezo2 channels and excitation of the neuron.

Local shape descriptors for neuron segmentation

We present an auxiliary learning task for the problem of neuron segmentation in electron microscopy volumes. The auxiliary task consists of the prediction of local shape descriptors (LSDs), which we combine with conventional voxel-wise direct neighbor affinities for neuron boundary detection. The shape descriptors capture local statistics about the neuron to be segmented, such as diameter, elongation, and direction. On a study comparing several existing methods across various specimen, imaging techniques, and resolutions, auxiliary learning of LSDs consistently increases segmentation accuracy of affinity-based methods over a range of metrics. Furthermore, the addition of LSDs promotes affinity-based segmentation methods to be on par with the current state of the art for neuron segmentation (flood-filling networks), while being two orders of magnitudes more efficient-a critical requirement for the processing of future petabyte-sized datasets.

Human Adipose-Derived Stromal Cells Delivered on Decellularized Muscle Improve Muscle Regeneration and Regulate RAGE and P38 MAPK

Volumetric muscle loss (VML) is the acute loss of muscle mass due to trauma. Such injuries occur primarily in the extremities and are debilitating, as there is no clinical treatment to restore muscle function. Pro-inflammatory advanced glycation end-products (AGEs) and the soluble receptor for advanced glycation end-products (RAGE) are known to increase in acute trauma patient’s serum and are correlated with increased injury severity. However, it is unclear whether AGEs and RAGE increase in muscle post-trauma. To test this, we used decellularized muscle matrix (DMM), a pro-myogenic, non-immunogenic extracellular matrix biomaterial derived from skeletal muscle. We delivered adipose-derived stromal cells (ASCs) and primary myoblasts to support myogenesis and immunomodulation (N = 8 rats/group). DMM non-seeded and seeded grafts were compared to empty defect and sham controls. Then, 56 days after surgery muscle force was assessed, histology characterized, and protein levels for AGEs, RAGE, p38 MAPK, and myosin heavy chains were measured. Overall, our data showed improved muscle regeneration in ASC-treated injury sites and a regulation of RAGE and p38 MAPK signaling, while myoblast-treated injuries resulted in minor improvements. Taken together, these results suggested that ASCs combined with DMM provides a pro-myogenic microenvironment with immunomodulatory capabilities and indicates further exploration of RAGE signaling in VML.

Inhibition of the futalosine pathway for menaquinone biosynthesis suppresses Chlamydia trachomatis infection

Chlamydia trachomatis, an obligate intracellular bacterium with limited metabolic capabilities, possesses the futalosine pathway for menaquinone biosynthesis. Futalosine pathway enzymes have promise as narrow-spectrum antibiotic targets, but the activity and essentiality of chlamydial menaquinone biosynthesis have yet to be established. In this work, menaquinone-7 (MK-7) was identified as a C. trachomatis-produced quinone through liquid chromatography-tandem mass spectrometry. An immunofluorescence-based assay revealed that treatment of C. trachomatis-infected HeLa cells with the futalosine pathway inhibitor docosahexaenoic acid (DHA) reduced inclusion number, inclusion size, and infectious progeny. Supplementation with MK-7 nanoparticles rescued the effect of DHA on inclusion number, indicating that the futalosine pathway is a target of DHA in this system. These results open the door for menaquinone biosynthesis inhibitors to be pursued in antichlamydial development.

Automatic detection of synaptic partners in a whole-brain Drosophila electron microscopy data set

We develop an automatic method for synaptic partner identification in insect brains and use it to predict synaptic partners in a whole-brain electron microscopy dataset of the fruit fly. The predictions can be used to infer a connectivity graph with high accuracy, thus allowing fast identification of neural pathways. To facilitate circuit reconstruction using our results, we develop CIRCUITMAP, a user interface add-on for the circuit annotation tool CATMAID.

Dental Restrictions to Clinical Practice during the COVID-19 Pandemic: An Australian Perspective

KNOWLEDGE TRANSFER STATEMENT

The reportedly low COVID-19 transmission occurring in dental settings highlight achievements made by the dental profession. There are valid reasons to reconsider risk-based essential oral healthcare during the COVID-19 pandemic.

Reconstruction of motor control circuits in adult Drosophila using automated transmission electron microscopy

To investigate circuit mechanisms underlying locomotor behavior, we used serial-section electron microscopy (EM) to acquire a synapse-resolution dataset containing the ventral nerve cord (VNC) of an adult female Drosophila melanogaster. To generate this dataset, we developed GridTape, a technology that combines automated serial-section collection with automated high-throughput transmission EM. Using this dataset, we studied neuronal networks that control leg and wing movements by reconstructing all 507 motor neurons that control the limbs. We show that a specific class of leg sensory neurons synapses directly onto motor neurons with the largest-caliber axons on both sides of the body, representing a unique pathway for fast limb control. We provide open access to the dataset and reconstructions registered to a standard atlas to permit matching of cells between EM and light microscopy data. We also provide GridTape instrumentation designs and software to make large-scale EM more accessible and affordable to the scientific community.

Dense neuronal reconstruction through X-ray holographic nano-tomography

Imaging neuronal networks provides a foundation for understanding the nervous system, but resolving dense nanometer-scale structures over large volumes remains challenging for light microscopy (LM) and electron microscopy (EM). Here we show that X-ray holographic nano-tomography (XNH) can image millimeter-scale volumes with sub-100-nm resolution, enabling reconstruction of dense wiring in Drosophila melanogaster and mouse nervous tissue. We performed correlative XNH and EM to reconstruct hundreds of cortical pyramidal cells and show that more superficial cells receive stronger synaptic inhibition on their apical dendrites. By combining multiple XNH scans, we imaged an adult Drosophila leg with sufficient resolution to comprehensively catalog mechanosensory neurons and trace individual motor axons from muscles to the central nervous system. To accelerate neuronal reconstructions, we trained a convolutional neural network to automatically segment neurons from XNH volumes. Thus, XNH bridges a key gap between LM and EM, providing a new avenue for neural circuit discovery.

545 Deep learning/artificial intelligence for automatic measurement of global longitudinal strain by echocardiography

Funding Acknowledgements

The Norwegian Health Association, South-Eastern Norway regional health Authority and the national program for clinical therapy research (KLINBEFORSK).

Background

Global longitudinal strain (GLS) by echocardiography has incremental prognostic value in patients with acute myocardial infarction and heart failure compared to left ventricular (LV) ejection fraction and provides more reproducible measurements of LV function. Recent advances in machine learning for image analysis now open the possibility for robust fully automated tracing of the LV and measurement of global longitudinal strain (GLS), without any operator input. This could make real-time GLS possible and remove inter-reader variability, thus resulting in saved time and improved test-retest reliability. The aim of the present study was to investigate how measurements by this novel automatic method compares to conventional speckle tracking analyses of GLS.

Methods

100 transthoracic echocardiographic examinations were included from a clinical database of patients with acute myocardial infarction or de-novo heart failure. Examinations were included consecutively and regardless of image quality. Simpson biplane LV ejection fraction ranged from 7 to 70%. Images of three standard apical planes from each examination were analysed using our novel and fully automated GLS method based on deep learning technology. The automated GLS measurements were compared to conventional speckle tracking GLS measurements of the same acquisitions using vendor specific format and software (EchoPAC, GE Healthcare), performed by a single experienced observer.

Results

GLS was -11.6 ± 4.5% and -12.8 ± 5.0% for the deep learning method and the conventional method, respectively. Bland-Altman analysis showed a bias of -0.7 ± 1,9% and 95% limits of agreement of -4,6 to 3.1. No clear value dependent bias was found by visual inspection (Figure A). Feasibility for measurement of GLS was 93% for the deep learning based method and 99% for the conventional method. The limits of agreement found in our study is comparable to findings in the intervendor comparison study by the EASCVI/ASE/Industry Task force to standardize deformation imaging.

Conclusion

This novel deep learning based method succeeds without any operator input to automatically identify and classify the three apical standard views, trace the myocardium, perform motion estimation and measure global longitudinal strain. This could further facilitate the clinical use of GLS as an important tool for enhancing clinical decision-making.

Abstract 545 Figure.

P1428 Mortality in non-ischemic cardiomyopathy is low and close to the general population

Funding Acknowledgements

South Eastern Norway regional health authority

Background

Patients with non-ischemic dilated cardiomyopathy (NDCM) have lower mortality compared to patients with ischemic cardiomyopathy (ICM). Recent reports suggest less benefit of a primary prophylactic implantable cardioverter defibrillator (ICD) in NDCM.

Purpose

We aimed to investigate mortality rate and appropriate ICD therapy in a consecutive cohort of patients with NDCM and ICM.

Methods

In this prospective multi-center study, we consecutively included NDCM and ICM patients with left ventricular ejection fraction (LVEF) &lt; 40% from July 2014 to January 2018. ICM or NDCM classification was based on coronary angiography. Echocardiography was performed at inclusion and LVEF and global longitudinal strain (GLS) were assessed. All-cause mortality and primary prevention ICD therapies were recorded during follow-up.

Results

We included 290 patients (67 ± 13 years old, 74% males), 207 with ICM and 83 with NDCM. At inclusion LVEF was 31 ± 6% and GLS -10.5 ± -3.3%. Patients with ICM were older (68 ± 12 years vs. 63 ± 15 years, p &lt; 0.01), had better LVEF (32 ± 6% vs. 28 ± 7%, p &lt; 0.01), and shorter QRS duration (106 ± 23 ms vs. 122 ± 28 ms, p &lt; 0.01). A primary prevention ICD was implanted in 18 (9%) ICM patients and in 21 (25%) NDCM patients (p &lt; 0.001).

During 22 ±12 months follow up, all-cause mortality was 27 (9%) in the entire population. In patients with ICM 1/18 (6%) received appropriate shock from their primary prevention ICD compared to 3/21 (14%) NDCM patients. Mortality was more frequent in ICM; 26/207 (13%) compared to 1/83 (1.2%) in NDCM (Log rank p &lt; 0.01). All-cause mortality or appropriate ICD shock was more frequent in ICM compared to NDCM (27 (13%) vs. 4 (5%) log rank p = 0.02) (Figure). Assuming the arrhythmias treated by the ICD shocks would have been lethal, annual mortality of 2.5% in the NDCM population was only slightly higher compared to the age matched general population (1% annual mortality) (blue line).

Conclusion

Patients with NDCM had better survival, and in general a lower event rate, compared to patients with ICM. However, subgroups of NDCM patients may benefit from their primary prophylactic ICD and further studies should investigate the need of primary prevention ICD in patients with NDCM.

Abstract P1428 Figure.

Insights into the Autoproteolytic Processing and Catalytic Mechanism of the Chlamydia trachomatis Virulence-Associated Protease CPAF

CPAF (chlamydial protease-like activity factor) is a Chlamydia trachomatis protease that is translocated into the host cytosol during infection. CPAF activity results in dampened host inflammation signaling, cytoskeletal remodeling, and suppressed neutrophil activation. Although CPAF is an emerging antivirulence target, its catalytic mechanism has been unexplored to date. Steady state kinetic parameters were obtained for recombinant CPAF with vimentin-derived peptide substrates using a high-performance liquid chromatography-based discontinuous assay (k_cat = 45 ± 0.6 s^-1; k_cat/K_m = 0.37 ± 0.02 μM^-1 s^-1) or a new fluorescence-based continuous assay (k_cat = 23 ± 0.7 s^-1; k_cat/K_m = 0.29 ± 0.03 μM^-1 s^-1). Residues H105, S499, E558, and newly identified D103 were found to be indispensable for autoproteolytic processing by mutagenesis, while participation of C500 was ruled out despite its proximity to the S499 nucleophile. Pre-steady state kinetics indicated a burst kinetic profile, with fast acylation (k_acyl = 110 ± 2 s^-1) followed by slower, partially rate-limiting deacylation (k_deacyl = 57 ± 1 s^-1). Both k_cat- and k_cat/K_m-pH profiles showed single acidic limb ionizations with pK_a values of 6.2 ± 0.1 and 6.5 ± 0.1, respectively. A forward solvent deuterium kinetic isotope effect of 2.6 ± 0.1 was observed for ^D₂Ok_cat^app, but a unity effect was found for ^D₂Ok_cat/K_m^app. The k_cat proton inventory was linear, indicating transfer of a single proton in the rate-determining transition state, most likely from H105. Collectively, these data provide support for the classification of CPAF as a serine protease and provide a mechanistic foundation for the future design of inhibitors.

A subperiosteal maxillary implant causing severe osteolysis

Subperiosteal implant denture therapy was initially introduced in 1942 in Sweden and was subsequently used worldwide for the treatment of fully edentulous maxillary or mandibular arches with advanced bone atrophy. Most authors describe decent success rates for mandibular subperiosteal implants in cases with major bone atrophy but follow-up studies for maxillary subperiosteal implants are not available. Here, we report a case of severe maxillary osteolysis secondary to the placement of a subperiosteal in-house implant. Subperiosteal implants are rarely used today but patients still carrying these devices can be challenging to manage when severe complications occur. New technical advances, including the use of surgical planification and additive manufacturing, may lead to a new interest in subperiosteal implants.

Systematic review with meta-analysis: prevalence, risk factors and costs of aminosalicylate use in Crohn's disease

BACKGROUND

Aminosalicylates are the most frequently prescribed drugs for patients with Crohn's disease (CD), yet evidence to support their efficacy as induction or maintenance therapy is controversial.

AIMS

To quantify aminosalicylate use in CD clinical trials, identify factors associated with use and estimate direct annual treatment costs of therapy.

METHODS

MEDLINE, Embase and CENTRAL were searched to April 2017 for placebo-controlled trials in adults with CD treated with corticosteroids, immunosuppressants or biologics. The proportion of patients co-prescribed aminosalicylates in placebo arms was pooled using a random-effects model. Meta-regression was used to identify factors associated with aminosalicylate use. Annual treatment costs were estimated using the 2016 Ontario Drug Benefit Program.

RESULTS

Forty-two induction and 10 maintenance trials were included. The pooled proportion of patients co-prescribed aminosalicylates was 44% [95% CI: 39%-49%] in induction trials and 49% [95% CI: 35%-64%] in maintenance trials. There was substantial to considerable heterogeneity (I²  = 86.0%, 91.8% for induction and maintenance trials, respectively). In multivariable meta-regression, aminosalicylate use has decreased over time in induction trials (OR 0.50 [95% CI: 0.34-0.74] per 10-year increment). While a decline has been seen over time, 35% of CD patients were still using aminosalicylates in contemporary trials from the last 5 years. The estimated annual cost for the lowest price mesalazine (mesalamine) formulation is approximately $32 million for the Canadian CD population.

CONCLUSIONS

Over one-third of CD patients entering clinical trials are still co-prescribed aminosalicylates. A definitive trial is needed to inform the conventional practice of using aminosalicylates as CD maintenance therapy.

Systematic review with meta-analysis: endoscopic and histologic placebo rates in induction and maintenance trials of ulcerative colitis

BACKGROUND

Regulatory requirements for claims of mucosal healing in ulcerative colitis (UC) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development.

AIMS

To meta-analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials (RCTs) and identify factors influencing these rates.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo-controlled trials of pharmacological interventions for UC. Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta-regression was used to evaluate the influence of patient, intervention and trial-related study-level covariates on these rates.

RESULTS

Fifty-six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval (CI) 19-28%] and 35% [95% CI 27-42%] respectively, and 20% [95% CI 16-24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8-22%] for induction trials. High heterogeneity was observed for all outcomes (I² 56.2%-88.3%). On multivariable meta-regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29-0.92], P = 0.03). On univariable meta-regression, higher histologic placebo remission was associated with concomitant corticosteroids (OR = 1.17 [95% CI 1.08-1.26], P < 0.0001, per 10% increase in corticosteroid use).

CONCLUSIONS

Placebo endoscopic and histologic rates range from 14% to 35% in UC RCTs but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.

Species composition and level of infestation of cockroaches in three areas in Hanoi

A study on the species composition and the level of infestation of cockroaches was carried out from April 2013 to October 2014 in three localities of Hanoi, Vietnam, namely the Lan Ong-Old Town, Linh Dam condominium and Tan Da Resort. Out of the 187 units of premises examined, 44.9% of units were infested with cockroaches. A total of 576 cockroaches were trapped, of which six species were identified: Periplaneta americana (L.) was the most dominant species (72.1%), followed by Blattella germanica (L.) (14.8%), Pycnoscelus surinamensis (L.) (7.3%), Periplaneta australasiae (Fabricius) (2.9%), Periplaneta fuliginosa (Serville) (1.9%) and Supella longipalpa (Fabricius) (1.0%). Infestation was the highest in Lan Ong (74.0%), followed by Linh Dam (40.5%) and Tan Da (25.9%). Cockroaches were abundantly found in warehouses (100%), electrical distribution room (56.3%), and kitchens (46.7%).

Fatigue-induced microdamage in cancellous bone occurs distant from resorption cavities and trabecular surfaces

Impaired bone toughness is increasingly recognized as a contributor to fragility fractures. At the tissue level, toughness is related to the ability of bone tissue to resist the development of microscopic cracks or other tissue damage. While most of our understanding of microdamage is derived from studies of cortical bone, the majority of fragility fractures occur in regions of the skeleton dominated by cancellous bone. The development of tissue microdamage in cancellous bone may differ from that in cortical bone due to differences in microstructure and tissue ultrastructure. To gain insight into how microdamage accumulates in cancellous bone we determined the changes in number, size and location of microdamage sites following different amounts of cyclic compressive loading. Human vertebral cancellous bone specimens (n=32, 10 male donors, 6 female donors, age 76 ± 8.8, mean ± SD) were subjected to sub-failure cyclic compressive loading and microdamage was evaluated in three-dimensions. Only a few large microdamage sites (the largest 10%) accounted for 70% of all microdamage caused by cyclic loading. The number of large microdamage sites was a better predictor of reductions in Young's modulus caused by cyclic loading than overall damage volume fraction (DV/BV). The majority of microdamage volume (69.12 ± 7.04%) was located more than 30 μm (the average erosion depth) from trabecular surfaces, suggesting that microdamage occurs primarily within interstitial regions of cancellous bone. Additionally, microdamage was less likely to be near resorption cavities than other bone surfaces (p<0.05), challenging the idea that stress risers caused by resorption cavities influence fatigue failure of cancellous bone. Together, these findings suggest that reductions in apparent level mechanical performance during fatigue loading are the result of only a few large microdamage sites and that microdamage accumulation in fatigue is likely dominated by heterogeneity in tissue material properties rather than stress concentrations caused by micro-scale geometry.

High prevalence of genu varum/valgum in European children with low vitamin D status and insufficient dairy products/calcium intakes

OBJECTIVE

The prevalence of lower limb deformities physiologically decreases after 5 years of age. It remains high in some tropical and subtropical regions where it has been associated with severe vitamin D deficiency, low calcium/milk intakes, malnutrition, and/or fluoride overexposure. Very little data is available in apparently healthy Caucasian children and adolescents.

DESIGN

We evaluated the prevalence of genu varum/valgum and other clinical symptoms, and assessed vitamin D status and markers of calcium metabolism in 226 apparently healthy European full-time boarders (7-16 years) seen during winter-spring and fed a cereal-based diet with little access to meat, milk, and dairy products. A cohort of 71 white children and adolescents hospitalized for acute illness served as age-matched controls.

RESULTS

Association studies showed a high prevalence of lower limb deformities (36%) and higher alkaline phosphate activities in the 21% of children and adolescent full-time boarders with serum 25-(OH)D levels ≤ 30 nmol/l, and low serum calcium in the 74% of boarders with 25-(OH)D levels ≤ 50 nmol/l, compared with boarders with higher vitamin D status. No such anomalies were found in the control cohort despite lower serum 25-(OH)D levels.

CONCLUSIONS

Low 25-(OH)D levels, at least during winter-spring, combined with additional risk factors such as very low calcium/milk intakes and possibly digestive disorders, are associated with an increased risk of genu varum/valgum in European children and adolescents. Thus, dietary fortification, or supplementation with vitamin D, may be recommended, at least during the winter, to European children and adolescents with either none or insufficient calcium/dairy product intakes.

High prevalence of genu varum/valgum in European children with low vitamin D status and insufficient dairy products/calcium intakes

OBJECTIVE

The prevalence of lower limb deformities physiologically decreases after 5 years of age. It remains high in some tropical and subtropical regions where it has been associated with severe vitamin D deficiency, low calcium/milk intakes, malnutrition, and/or fluoride overexposure. Very little data is available in apparently healthy Caucasian children and adolescents.

DESIGN

We evaluated the prevalence of genu varum/valgum and other clinical symptoms, and assessed vitamin D status and markers of calcium metabolism in 226 apparently healthy European full-time boarders (7-16 years) seen during winter-spring and fed a cereal-based diet with little access to meat, milk, and dairy products. A cohort of 71 white children and adolescents hospitalized for acute illness served as age-matched controls.

RESULTS

Association studies showed a high prevalence of lower limb deformities (36%) and higher alkaline phosphate activities in the 21% of children and adolescent full-time boarders with serum 25-(OH)D levels ≤ 30 nmol/l, and low serum calcium in the 74% of boarders with 25-(OH)D levels ≤ 50 nmol/l, compared with boarders with higher vitamin D status. No such anomalies were found in the control cohort despite lower serum 25-(OH)D levels.

CONCLUSIONS

Low 25-(OH)D levels, at least during winter-spring, combined with additional risk factors such as very low calcium/milk intakes and possibly digestive disorders, are associated with an increased risk of genu varum/valgum in European children and adolescents. Thus, dietary fortification, or supplementation with vitamin D, may be recommended, at least during the winter, to European children and adolescents with either none or insufficient calcium/dairy product intakes.

The heterogeneity of adult neural stem cells and the emerging complexity of their niche

Neural stem cells persist in the adult mammalian brain in a neurogenic niche known as the subventricular zone (SVZ). SVZ neural stem cells (NSCs) can self-renew and are multipotent in culture. In rodents, adult NSCs correspond to SVZ astrocytes (type B cells) that are derived from radial glia, the NSCs of the embryonic and early postnatal brain. Type B cells generate transit-amplifying (type C) cells that give rise to young neurons (type A cells) and oligodendrocytes. Young neurons are born throughout the adult neurogenic niche and migrate tangentially through a complex network of chains that merge into the rostral migratory stream (RMS), a major pathway that leads into the olfactory bulb (OB). Within the OB, young neurons differentiate into multiple types of interneurons. The SVZ was thought to be limited to the lateral wall of the lateral ventricle, but recent work shows that the adult neurogenic niche is significantly more extensive and includes portions of the medial and dorsal walls of the lateral ventricle and the RMS itself. Furthermore, several recent studies explain why young OB neurons are generated in such an extensive region. Type B cells in different regions of the SVZ, although able to self-renew and generate both neurons and glial cells in vitro, are heterogeneous and committed to producing defined neuronal subtypes in vivo. The adult SVZ therefore provides a rich system to study not only neural replacement, but also the cellular and molecular mechanisms underlying regionalization and cell-fate specification.

Neurodegeneration associated with genetic defects in phospholipase A(2)

OBJECTIVE

Mutations in the gene encoding phospholipase A(2) group VI (PLA2G6) are associated with two childhood neurologic disorders: infantile neuroaxonal dystrophy (INAD) and idiopathic neurodegeneration with brain iron accumulation (NBIA). INAD is a severe progressive psychomotor disorder in which axonal spheroids are found in brain, spinal cord, and peripheral nerves. High globus pallidus iron is an inconsistent feature of INAD; however, it is a diagnostic criterion of NBIA, which describes a clinically and genetically heterogeneous group of disorders that share this hallmark feature. We sought to delineate the clinical, radiographic, pathologic, and genetic features of disease resulting from defective phospholipase A(2).

METHODS

We identified 56 patients clinically diagnosed with INAD and 23 with idiopathic NBIA and screened their DNA for PLA2G6 mutations.

RESULTS

Eighty percent of patients with INAD had mutations in PLA2G6, whereas mutations were found in only 20% of those with idiopathic NBIA. All patients with two null mutations had a more severe phenotype. On MRI, nearly all mutation-positive patients had cerebellar atrophy, and half showed brain iron accumulation. We observed Lewy bodies and neurofibrillary tangles in association with PLA2G6 mutations.

CONCLUSION

Defects in phospholipase A(2) lead to a range of phenotypes. PLA2G6 mutations are associated with nearly all cases of classic infantile neuroaxonal dystrophy but a minority of cases of idiopathic neurodegeneration with brain iron accumulation, and genotype correlates with phenotype. Cerebellar atrophy predicts which patients are likely to be mutation-positive. The neuropathologic changes that are caused by defective phospholipase A(2) suggest a shared pathogenesis with both Parkinson and Alzheimer diseases.

Percutaneous treatment of severe carotid stenosis due to Takayasu's arteritis early after carotid endarterectomy

Takayasu's arteritis is a chronic inflammatory disease primarily involving large vessels. The diffuse, multifocal and progressive nature of the vascular lesions make surgical repair difficult. We describe successful carotid stenting of a 39-year-old female who presented with symptomatic, aggressive, long-segment carotid restenosis 6 months following left carotid endarterectomy. Repeat angiography 6 months later revealed continued patency.

Tryptophan missense mutation in the ligand-binding domain of the vitamin D receptor causes severe resistance to 1,25-dihydroxyvitamin D

In this study, two related young children, brother and sister, exhibited severe vitamin D-resistant rickets without alopecia. Sequence analysis of the total vitamin D receptor (VDR) cDNA from skin fibroblasts revealed a substitution of the unique tryptophan of the VDR by arginine at amino acid 286 (W286R). Cultured skin fibroblasts of the two patients expressed normal-size VDR protein (immunocytochemistry and Western blotting) and normal length VDR mRNA (Northern blotting). But, these fibroblasts, as well as COS-7 cells transfected with the W286R mutant, failed to bind 3H 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. The tryptophan substitution did not affect VDR trafficking toward the nucleus but abolished the 24-hydroxylase gene response to 1,25(OH)2D3, even at 10(-6) M concentrations. In conclusion, this case report of a new family with hereditary vitamin D-resistant rickets (HVDRR) emphasizes the crucial role of the VDR tryptophan for ligand binding and for transactivation of 1,25(OH)2D3 target genes. It clearly shows the clinical significance of this VDR amino acid for calcium homeostasis and bone mineralization. This observation suggests further that the presence of a stable VDR-bound ligand may not be obligatory for normal hair follicle development.

A novel reactivity of SeO(2) with 1,3-dienes: formation of syn 1,2- and 1,4-diols via a facile C-Se bond oxidation

[reaction: see text] A novel reaction between 1,3-dienes and selenium dioxide to give syn 1,2- and 1,4-diol cyclic selenites was studied in detail. This study indicates that an initial concerted [4 + 2] cycloaddition followed by a stereospecific carbon-selenium bond oxidation is involved in this unprecedented syn dihydroxy addition reaction mediated by selenium dioxide.

[2',6'-Dimethyltyrosine]dynorphin A(1-11)-NH2 analogues lacking an N-terminal amino group: potent and selective kappa opioid antagonists

Recent studies showed that dermorphin and enkephalin analogues containing two methyl groups at the 2',6'-positions of the Tyr(1) aromatic ring and lacking an N-terminal amino group were moderately potent delta and mu opioid antagonists. These results indicate that a positively charged N-terminal amino group may be essential for signal transduction but not for receptor binding and suggested that its deletion in agonist opioid peptides containing an N-terminal 2',6'-dimethyltyrosine (Dmt) residue may represent a general way to convert them into antagonists. In an attempt to develop dynorphin A (Dyn A)-derived kappa opioid antagonists, we prepared analogues of [Dmt(1)]Dyn A(1-11)-NH2 (1), in which the N-terminal amino group was either omitted or replaced with a methyl group. This was achieved by replacement of Tyr(1) with 3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid (Dhp) or (2S)-2-methyl-3-(2,6-dimethyl-4-hydroxyphenyl)propanoic acid [(2S)-Mdp]. Compounds were tested in the guinea pig ileum and mouse vas deferens bioassays and in rat and guinea pig brain membrane receptor binding assays. All analogues turned out to be potent kappa antagonists against Dyn A(1-13) and the non-peptide agonist U50,488 and showed only weak mu and delta antagonist activity. The most potent and most selective kappa antagonist of the series was [(2S)-Mdp(1)]Dyn A(1-11)-NH2 (5, dynantin), which showed subnanomolar kappa antagonist potency against Dyn A(1-13) and very high kappa selectivity both in terms of its K(e) values determined against kappa, mu, and delta agonists and in terms of its ratios of kappa, mu, and delta receptor binding affinity constants. Dynantin is the first potent and selective Dyn A-derived kappa antagonist known and may complement the non-peptide kappa antagonists norbinaltorphimine and GNTI as a pharmacological tool in opioid research.

Pharmacological characterization of the dermorphin analog [Dmt(1)]DALDA, a highly potent and selective mu-opioid peptide

The dermorphin-derived peptide [Dmt(1)]DALDA (H-Dmt-D-Arg-Phe-Lys-NH(2)), labels mu-opioid receptors with high affinity and selectivity in receptor binding assays. In mouse, radiant heat tail-flick assay [Dmt(1)]DALDA produced profound spinal and supraspinal analgesia, being approximately 5000- and 100-fold more potent than morphine on a molar basis, respectively. When administered systemically, [Dmt(1)]DALDA was over 200-fold more potent than morphine. Pharmacologically, [Dmt(1)]DALDA was distinct from morphine. [Dmt(1)]DALDA displayed no cross-tolerance to morphine in the model used and it retained supraspinal analgesic activity in morphine-insensitive CXBK mice. Supraspinally, it also differed from morphine in its lack of sensitivity towards naloxonazine. Finally, in antisense mapping studies, [Dmt(1)]DALDA was insensitive to MOR-1 exon probes that reduced morphine analgesia, implying a distinct receptor mechanism of action. Thus, [Dmt(1)]DALDA is an interesting and extraordinarily potent, systemically active peptide analgesic, raising the possibility of novel approaches in the design of clinically useful drugs.

Solution structure of the squash trypsin inhibitor MCoTI-II. A new family for cyclic knottins

The "knottin" fold is a stable cysteine-rich scaffold, in which one disulfide crosses the macrocycle made by two other disulfides and the connecting backbone segments. This scaffold is found in several protein families with no evolutionary relationships. In the past few years, several homologous peptides from the Rubiaceae and Violaceae families were shown to define a new structural family based on macrocyclic knottin fold. We recently isolated from Momordica cochinchinensis seeds the first known macrocyclic squash trypsin inhibitors. These compounds are the first members of a new family of cyclic knottins. In this paper, we present NMR structural studies of one of them, MCoTI-II, and of a beta-Asp rearranged form, MCoTI-IIb. Both compounds display similar and well-defined conformations. These cyclic squash inhibitors share a similar conformation with noncyclic squash inhibitors such as CPTI-II, and it is postulated that the main effect of the cyclization is a reduced sensitivity to exo-proteases. On the contrary, clear differences were detected with the three-dimensional structures of other known cyclic knottins, i.e., kalata B1 or circulin A. The two-disulfide cystine-stabilized beta-sheet motif [Heitz et al. (1999) Biochemistry 38, 10615-10625] is conserved in the two families, whereas in the C-to-N linker, one disulfide bridge and one loop are differently located. The molecular surface of MCoTI-II is almost entirely charged in contrast to circulin A that displays a well-marked amphiphilic character. These differences might explain why the isolated macrocyclic squash inhibitors from M. cochinchinensis display no significant antibacterial activity, whereas circulins and kalata B1 do.

Relationship between normal amniotic fluid index and birth weight in term patients presenting for labor

OBJECTIVE

To investigate whether a relationship between birth weight (BW) and amniotic fluid index (AFI) existed for term patients with intact membranes and, if so, whether it could predict macrosomia and intrauterine growth retardation.

STUDY DESIGN

Two hundred thirty-one eligible women at term (37-42 weeks' gestation) had an AFI between 5.0 and 24.0 cm at the time of admission. Demographic information was collected, including BW. Statistical comparisons were made, with significance set at P < .05.

RESULTS

The mean gestational age was 39.5 weeks, and the mean AFI was 11.3. There were 28 infants with BWs > 4,000 g (macrosomia). The cesarean section rate was 16.9%. Macrosomia was associated with a higher cesarean section rate (39.2% vs. 13.8%, P < .002). The mean AFI was higher for those with macrosomia (13.5 vs. 11.0, P < .001). Patients with an AFI > 15.0 had over twice the incidence of macrosomia (RR 2.72, 1.1-6.6, 32.1% vs. 14.8%, P < .027). The risk was even greater for them with an AFI > 18.0 (RR 6.4, 2.2-18.7, P < .002). A linear relationship was observed between AFI and BW (r2 .061, P < .0001). BW increased with increasing AFI. No relationship between AFI of 5-8 and BW < 2,500 g was found.

CONCLUSION

Increasing AFI correlates linearly with increasing BW, and macrosomia is associated with an increased incidence of cesarean delivery. AFI > 15 carries over double the risk of birth of a macrosomic infant, while AFI > 18 has a risk of over six times. No association between low normal AFI and a growth-restricted infant was found.

Sequential use of Prepidil and extra-amniotic saline infusion for the induction of labor in nulliparous women with very low Bishop scores

OBJECTIVE

To evaluate the efficacy of sequential use of Prepidil (prostaglandin E2 gel) and extra-amniotic saline infusion for the induction of labor in nulliparous women with very low Bishop scores.

STUDY DESIGN

Nulliparous women with singleton gestations, intact membranes and a cervical Bishop score of < or = 2 who received Prepidil gel and extra-amniotic saline infusion sequentially for the induction of labor between July 1996 and July 1998 were studied.

RESULTS

Thirty-one women met the inclusion criteria. Indications for induction included post-dates (six of 31), pre-eclampsia (ten of 31), diabetes (three of 31), oligohydramnios (three of 31), intrauterine growth restriction (two of 31) and non-reactive non-stress test (NST) (seven of 31). The average time from onset of induction to delivery was 38.1 +/- 13.5 h. Vaginal delivery was achieved in 80.6%. Women requiring > 2 doses of Prepidil had a higher risk of delivering abdominally (OR = 3.5). Three of seven (42.9%) women with labor induced for non-reactive NST but only three of 24 (12.5%) with labor induced for other indications had a Cesarean section delivery (p < 0.001).

CONCLUSIONS

Nulliparous women with very unfavorable cervices can be counselled that they have an 80% chance of vaginal delivery using sequential Prepidil and extra-amniotic saline infusion as an induction method, with 90% delivering within the first 48 h.

Nuclear gems and Cajal (coiled) bodies in fetal tissues: nucleolar distribution of the spinal muscular atrophy protein, SMN

SMN, the affected protein in spinal muscular atrophy (SMA), is a cytoplasmic protein that also occurs in nuclear structures called "gems" and is involved in snRNP maturation. Coilin-p80 is a marker protein for nuclear Cajal bodies (coiled bodies; CBs) which are also involved in snRNP maturation, storage or transport. We now show that gems and CBs are present in all fetal tissues, even those that lack gems/CBs in the adult. Most gems and CBs occur as separate nuclear structures in fetal tissues, but their colocalization increases with fetal age and is almost complete in the adult. In adult tissues, up to half of all gems/CBs are inside the nucleolus, whereas in cultured cells they are almost exclusively nucleoplasmic. The nucleolar SMN is often more diffusely distributed, compared with nucleoplasmic gems. Up to 30% of cells in fetal tissues have SMN distributed throughout the nucleolus, instead of forming gems in the nucleoplasm. The results suggest a function for gems distinct from Cajal bodies in fetal nuclei and a nucleolar function for SMN. Spinal cord, the affected tissue in SMA, behaves differently in several respects. In both fetal and adult motor neurons, many gems/CBs occur as larger bodies closely associated with the nucleolar perimeter. Uniquely in motor neurons, gems/CBs are more numerous in adult than in fetal stages and colocalization of gems and CBs occurs earlier in development. These unusual features of motor neurons may relate to their special sensitivity to reduced SMN levels in SMA patients.

In vitro comparison of peak polymerization temperatures of 5 provisional restoration resins

BACKGROUND

The heat produced by provisional restoration materials may injure the dental pulp. This study measured and compared peak temperatures during polymerization of 5 materials used in the fabrication of provisional restorations.

METHODS

The tested materials were 2 self-curing resins (Integrity and Protemp) and 3 dual-cure resins (Iso-Temp, TCB Dual Cure and Provipont DC). A mould the size of a maxillary molar tooth was fabricated to contain 0.5 cc of resin. The temperature rise of the different materials was recorded every 10 seconds over a 10-minute period.

RESULTS

The rise in temperature of Integrity (peak temperature of 33.8 degrees C) and Protemp Garant (35.6 degrees C) was significantly higher than the rise in temperature of Iso-Temp (29.5 degrees C), TCB Dual Cure (28.4 degrees C) and Provipont DC (29.5 degrees C).

CONCLUSION

Use of the dual-cure resins in provisional restorations may reduce the risk of pulp injury.

Synthesis and in vitro opioid activity profiles of DALDA analogues

The tetrapeptide DALDA (H-Tyr-D-Arg-Phe-Lys-NH2) is a polar and selective mu agonist showing poor penetration of the placental and blood-brain barriers. In an effort to enhance the potency of DALDA, analogues containing 2',6'-dimethyltyrosine (Dmt), N,2',6'-trimethyltyrosine (Tmt), 2'-methyltyrosine (Mmt) or 2'-hydroxy,6'-methyltyrosine (Hmt) in place of Tyr1, or Orn or alpha,gamma-diaminobutyric acid (A2bu) in place of Lys4, were synthesized. All compounds displayed high mu receptor selectivity in the rat and guinea pig brain membrane binding assays and most of them were more potent mu agonists than DALDA in the mu receptor-representative guinea pig ileum assay, with [Dmt1]DALDA showing the highest potency. Because of its extraordinary mu agonist potency, high mu selectivity, polar character (charge of 3 + ) and metabolic stability, [Dmt1]DALDA has potential for use in obstetrical or peripheral analgesia.

Expectant management of severe preterm preeclampsia: is intrauterine growth restriction an indication for immediate delivery?

OBJECTIVE

Expectant management of severe preterm preeclampsia is gaining widespread acceptance in clinical practice. The objective of our study was 2-fold-to determine the frequency of fetal deterioration with expectant management of severe preterm preeclampsia and to evaluate whether the presence of intrauterine growth restriction on admission is associated with a shorter admission-to-delivery interval or more deliveries resulting from nonreassuring fetal status in comparison with pregnancies with preeclampsia but without intrauterine growth restriction.

STUDY DESIGN

This was an observational study of women with singleton pregnancies at <34 completed weeks' gestation who were admitted to the hospital with the diagnosis of severe preeclampsia and managed expectantly. Fetal status on admission, admission-to-delivery interval, indication for delivery, and neonatal outcome were examined.

RESULTS

Forty-seven women were studied during a 3-year period (1996-1999). Gestational age at admission was 29.8 +/- 2.6 weeks. The mean admission-to-delivery interval for the entire group was 6.0 +/- 5.1 days; in 42.5% delivery was for fetal indications. In comparison with the absence of intrauterine growth restriction, the presence of intrauterine growth restriction at admission resulted in a significantly shorter admission-to-delivery interval (3.1 +/- 2.1 vs 6.6 +/- 6.1 days; P <.05). Most fetuses with intrauterine growth restriction (85.7%) were delivered before 1 week. Although 57% of fetuses with intrauterine growth restriction were delivered for fetal indications, versus 39% of fetuses without intrauterine growth restriction, these rates were not found to be significantly different. Neonatal outcomes, as reflected by Apgar scores, number of admissions to and duration of stay in the neonatal intensive care unit, and neonatal mortality rates, were similar.

CONCLUSION

Pregnancies complicated by severe preterm preeclampsia and the presence of intrauterine growth restriction at admission may not benefit from expectant management beyond the 48 hours needed for betamethasone to act. Furthermore, all patients may benefit from close fetal monitoring before delivery because of the high rate of intervention for deteriorating fetal status.

Digital overlay technique for documenting toric intraocular lens axis orientation

PURPOSE

To describe a digital overlay technique for documenting toric intraocular lens (IOL) axis alignment.

SETTING

Jules Stein Eye Institute and the Department of Ophthalmology, University of California at Los Angeles School of Medicine, Los Angeles, California, USA.

METHODS

Digital overlay imaging was used to evaluate the alignment of Staar toric IOLs in 4 eyes of 3 patients who had regular corneal astigmatism at the time of cataract surgery. Lens axes were determined by computerized analysis of digitally scanned retroillumination photographs. A stock digital image of a Staar AA4203TF toric IOL was superimposed on corneal topography images to document IOL alignment with the steep corneal meridian.

RESULTS

Digital overlay images demonstrated that 3 IOLs in the sample group were within 5 degrees and 1 was within 20 degrees of the intended axis at the time of the final postoperative examination. Slitlamp lens axis estimations were 3 to 18 degrees different from that determined by this technique.

CONCLUSION

Digital overlay imaging of correctly oriented toric IOLs on computerized corneal topography maps represents an intuitive, accurate, and visually appealing method of documenting toric IOL axis alignment.

Characterization of a monoclonal antibody panel shows that the myotonic dystrophy protein kinase, DMPK, is expressed almost exclusively in muscle and heart

Myotonic dystrophy (DM) is a multisystemic disorder caused by an inherited CTG repeat expansion which affects three genes encoding the DM protein kinase (DMPK), a homeobox protein Six5 and a protein containing WD repeats. Using a panel of 16 monoclonal antibodies against several different DMPK epitopes we detected DMPK, as a single protein of approximately 80 kDa, only in skeletal muscle, cardiac muscle and, to a lesser extent, smooth muscle. Many earlier reports of DMPK with different sizes and tissue distributions appear to be due to antibody cross-reactions with more abundant proteins. One such antibody, MANDM1, was used to isolate two related protein kinases, MRCK alpha and beta, from a human brain cDNA library and the shared epitope was located at the catalytic site of DMPK using a phage-displayed random peptide library. The peptide library also identified an epitope shared between DMPK and a 55 kDa muscle-specific protein. The results suggest that effects of the repeat expansion on the DMPK gene may be responsible for muscle and heart features of DM, whereas clinical changes in other tissues may be due to effects on the other two genes.

The TIPP opioid peptide family: development of delta antagonists, delta agonists, and mixed mu agonist/delta antagonists

The discovery of the prototype delta opioid antagonists TIPP (H-Tyr-Tic-Phe-Phe-OH) and TIP (H-Tyr-Tic-Phe-OH) in 1992 was followed by extensive structure-activity relationship studies, leading to the development of analogues that are of interest as pharmacological tools or as potential therapeutic agents. Stable TIPP-derived delta opioid antagonists with subnanomolar delta receptor binding affinity and extraordinary delta receptor selectivity include TIPP[Psi] (H-Tyr-TicPsi[CH(2)NH]Phe-Phe-OH] and TICP[Psi] (H-Tyr-TicPsi[CH(2)NH]Cha-Phe-OH); Cha: cyclohexylalanine), which are widely used in opioid research. Theoretical conformational analyses in conjunction with the pharmacological characterization of conformationally constrained TIPP analogues led to a definitive model of the receptor-bound conformation of H-Tyr-Tic-(Phe-Phe)-OH-related delta opioid antagonists, which is characterized by all-trans peptide bonds. Further structure-activity studies revealed that the delta antagonist vs delta agonist behavior of TIP(P)-derived compounds depended on very subtle structural differences in diverse locations of the molecule and suggested a delta receptor model involving a number of different inactive receptor conformations. A further outcome of these studies was the identification of a new class of potent and very selective dipeptide delta agonists of the general formula H-Tyr-Tic-NH-X (X = arylalkyl), which are of interest for drug development because of their low molecular weight and lipophilic character. Most interestingly, TIPP analogues containing a C-terminal carboxamide group displayed a mixed mu agonist/delta antagonist profile, and thus were expected to be analgesics with a low propensity to produce tolerance and physical dependence. This turned out to be the case with the TIPP-derived mu agonist/delta antagonist DIPP-NH(2)[Psi] (H-Dmt-TicPsi[CH(2)NH]Phe-Phe-NH(2)); Dmt: 2',6'- dimethyltyrosine).

Matrix-assisted laser desorption/ionization mass spectrometric quantification of the mu opioid receptor agonist DAMGO in ovine plasma

The synthetic opioid peptide analog Tyr-D-Ala-Gly-N-methyl-Phe-Gly-ol (DAMGO), which is a mu opioid receptor-selective agonist, was quantified in ovine plasma samples with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), using delayed extraction and a reflectron. The internal standard was pentadeuterated DAMGO. Timed-ion selection was used to select the precursor ion. The analysis of the post-source decay fragments improved the detection sensitivity, and the use of the precursor-product ion relationship optimized the specificity. For plasma samples, the inter-assay variability of this method was 6.4% (n = 79) and the intra-assay variability was 6.0% (n = 10). The variability for controls was 3.4% (n = 43). The profile of DAMGO amount versus time was determined in sheep plasma, and the corresponding pharmacokinetic data were calculated.

Squash trypsin inhibitors from Momordica cochinchinensis exhibit an atypical macrocyclic structure

Three trypsin inhibitors (TIs), from the seeds of the squash Momordica cochinchinensis (MCo), have been isolated and purified using gel filtration, ion exchange chromatography, and reverse-phase HPLC. Their sequences could be determined only after proteolytic cleavages. In the case of MCoTI-I and -II, it was shown that their polypeptide backbones are cyclic, a structure that has never been described in squash TIs. They contain 34 amino acid residues with 3 disulfide bridges and measured molecular masses of 3453.0 and 3480.7, respectively. They are the largest known macrocyclic peptides containing disulfide bridges. Their sequences show strong homology to other squash TIs, suggesting a similar three-dimensional structure and an analogous mechanism of action. A model of MCoTI-II was constructed by analogy to the crystal structure of the complex between bovine trypsin and CMTI-I, indicating that the linker connecting the two termini is flexible and does not impose significant geometrical constraints. This flexibility allows an Asp-Gly peptide bond rearrangement to occur in this region, giving rise to two isoforms of MCoTI-II. Although the importance of cyclization is not clear, it might confer increased stability and resistance to proteolysis. A minor species, MCoTI-III, was also characterized as containing 30 amino acid residues with a molecular mass of 3379.6. This component possesses a linear backbone with a blocked N-terminus. MCoTIs represent interesting candidates for drug design, either by changing their specificity of inhibition or by using their structure as natural scaffolds bearing new binding activities.

Imaging the sphenoid sinus: pictorial essay

This paper focuses on the spectrum of sphenoid sinus lesions that may be seen radiologically and the mapping of disease extent. Imaging plays a central role in the assessment of sphenoid sinus disease. Although primary sphenoid sinus disease is uncommon, this sinus is nevertheless affected secondarily by a variety of pathological processes.