High-efficiency vertically emitting coupler facilitated by three wave interaction gratings.

We designed a grating coupler optimized for normal incidence and numerically demonstrate near-unity coupling in a standard 220-nm-thick silicon-on-insulator (SOI) technology. Our design breaks the vertical symmetry within the grating region by implementing three scattering sites per local period. This technique removes the need for bottom reflectors or additional material layers and can be realized using only two lithography masks. Using adjoint method-based optimization, we engineer the coupling spectrum of the grating, balancing the trade-off between peak efficiency and bandwidth. Using this technique, we simulate three devices with peak coupling efficiencies ranging between 93.4 (-0.3 dB) and 98.6% (-0.06 dB) with corresponding 1 dB bandwidths between 48 and 8 nm all centered around 1.55 µm.

Ebola Virus Uses Tunneling Nanotubes as an Alternate Route of Dissemination.

Ebola virus (EBOV) disease is marked by rapid virus replication and spread. EBOV enters the cell by macropinocytosis and replicates in the cytoplasm, and nascent virions egress from the cell surface to infect neighboring cells. Here, we show that EBOV uses an alternate route to disseminate: tunneling nanotubes (TNTs). TNTs, an actin-based long-range intercellular communication system, allows for direct exchange of cytosolic constituents between cells. Using live, scanning electron, and high-resolution quantitative 3-dimensional microscopy, we show that EBOV infection of primary human cells results in the enhanced formation of TNTs containing viral nucleocapsids. TNTs promote the intercellular transfer of nucleocapsids in the absence of live virus, and virus could replicate in cells devoid of entry factors after initial stall. Our studies suggest an alternate model of EBOV dissemination within the host, laying the groundwork for further investigations into the pathogenesis of filoviruses and, importantly, stimulating new areas of antiviral design.

Injectional anthrax at a Scottish district general hospital.

This retrospective, descriptive case-series reviews the clinical presentations and significant laboratory findings of patients diagnosed with and treated for injectional anthrax (IA) since December 2009 at Monklands Hospital in Central Scotland and represents the largest series of IA cases to be described from a single location. Twenty-one patients who fulfilled National Anthrax Control Team standardized case definitions of confirmed, probable or possible IA are reported. All cases survived and none required limb amputation in contrast to an overall mortality of 28% being experienced for this condition in Scotland. We document the spectrum of presentations of soft tissue infection ranging from mild cases which were managed predominantly with oral antibiotics to severe cases with significant oedema, organ failure and coagulopathy. We describe the surgical management, intensive care management and antibiotic management including the first description of daptomycin being used to treat human anthrax. It is noted that some people who had injected heroin infected with Bacillus anthracis did not develop evidence of IA. Also highlighted are biochemical and haematological parameters which proved useful in identifying deteriorating patients who required greater levels of support and surgical debridement.

Sequencing and phylogenetic characterisation of a fatal Crimean - Congo haemorrhagic fever case imported into the United Kingdom, October 2012.

A patient with fever, and haemorrhagic symptoms was admitted to a hospital in Glasgow on 2 October 2012. Since he had returned from Afghanistan, serum samples were sent for diagnosis at the Rare and Imported Pathogens Laboratory, where a real-time reverse transcriptase-PCR diagnosis of Crimean ­ Congo haemorrhagic fever was made within 3 hrs after receipt of the sample. Hereafter the patient was transferred to a high-security infectious diseases unit in London but died on 6 October.

The Early External Cephalic Version (ECV) 2 Trial: an international multicentre randomised controlled trial of timing of ECV for breech pregnancies.

OBJECTIVE: To investigate whether initiating external cephalic version (ECV) earlier in pregnancy might increase the rate of successful ECV procedures, and be more effective in decreasing the rate of non-cephalic presentation at birth and of caesarean section. DESIGN: An unblinded multicentred randomised controlled trial. SETTING: A total of 1543 women were randomised from 68 centres in 21 countries. POPULATION: Women with a singleton breech fetus at a gestational age of 33(0/7) weeks (231 days) to 35(6/7) weeks (251 days) of gestation were included. METHODS: Participants were randomly assigned to having a first ECV procedure between the gestational ages of 34(0/7) (238 days) and 35(6/7) weeks of gestation (early ECV group) or at or after 37(0/7) (259 days) weeks of gestation (delayed ECV group). MAIN OUTCOME MEASURES: The primary outcome was the rate of caesarean section; the secondary outcome was the rate of preterm birth. RESULTS: Fewer fetuses were in a non-cephalic presentation at birth in the early ECV group (314/765 [41.1%] versus 377/768 [49.1%] in the delayed ECV group; relative risk [RR] 0.84, 95% CI 0.75, 0.94, P=0.002). There were no differences in rates of caesarean section (398/765 [52.0%] versus 430/768 [56.0%]; RR 0.93, 95% CI 0.85, 1.02, P=0.12) or in risk of preterm birth (50/765 [6.5%] versus 34/768 [4.4%]; RR 1.48, 95% CI 0.97, 2.26, P=0.07) between groups. CONCLUSION: External cephalic version at 34-35 weeks versus 37 or more weeks of gestation increases the likelihood of cephalic presentation at birth but does not reduce the rate of caesarean section and may increase the rate of preterm birth.

Are medical procedures that induce coughing or involve respiratory suctioning associated with increased generation of aerosols and risk of SARS-CoV-2 infection? A rapid systematic review.

BACKGROUND: The risk of transmission of SARS-CoV-2 from aerosols generated by medical procedures is a cause for concern. AIM: To evaluate the evidence for aerosol production and transmission of respiratory infection associated with procedures that involve airway suctioning or induce coughing/sneezing. METHODS: The review was informed by PRISMA guidelines. Searches were conducted in PubMed for studies published between January 1st, 2003 and October 6th, 2020. Included studies examined whether nasogastric tube insertion, lung function tests, nasendoscopy, dysphagia assessment, or suctioning for airway clearance result in aerosol generation or transmission of SARS-CoV-2, SARS-CoV, MERS, or influenza. Risk of bias assessment focused on robustness of measurement, control for confounding, and applicability to clinical practice. FINDINGS: Eighteen primary studies and two systematic reviews were included. Three epidemiological studies found no association between nasogastric tube insertion and acquisition of respiratory infections. One simulation study found low/very low production of aerosols associated with pulmonary lung function tests. Seven simulation studies of endoscopic sinus surgery suggested significant increases in aerosols but findings were inconsistent; two clinical studies found airborne particles associated with the use of microdebriders/drills. Some simulation studies did not use robust measures to detect particles and are difficult to equate to clinical conditions. CONCLUSION: There was an absence of evidence to suggest that the procedures included in the review were associated with an increased risk of transmission of respiratory infection. In order to better target precautions to mitigate risk, more research is required to determine the characteristics of medical procedures and patients that increase the risk of transmission of SARS-CoV-2.

Associations between subunit ectodomains promote T cell antigen receptor assembly and protect against degradation in the ER.

The T cell antigen receptor (TCR) is an oligomeric protein complex made from at least six different integral membrane proteins (alpha beta gamma delta epsilon and zeta). The TCR is assembled in the ER of T cells, and correct assembly is required for transport to the cell surface. Single subunits and partial receptor complexes are retained in the ER where TCR alpha, beta, and CD3 delta chains are degraded selectively. The information required for the ER degradation of the TCR beta chain is confined to the membrane anchor of the protein (Wileman et al., 1990c; Bonifacino et al., 1990b). In this study we show that the rapid degradation of the TCR beta chain is inhibited when it assembles with single CD3 gamma, delta, or epsilon subunits in the ER, and have started to define the role played by transmembrane anchors, and receptor ectodomains, in the masking proteolytic targeting information. Acidic residues within the membrane spanning domains of CD3 subunits were essential for binding to the TCR beta chain. TCR beta chains and CD3 subunits therefore interact via transmembrane domains. However, when sites of binding were restricted to the membrane anchor of the TCR beta chain, stabilization by CD3 subunits was markedly reduced. Interactions between membrane spanning domains were not, therefore, sufficient for the protection of the beta chain from ER proteolysis. The presence of the C beta domain, containing the first 150 amino acids of the TCR ectodomain, greatly increased the stability of complexes formed in the ER. For assembly with CD3 epsilon, stability was further enhanced by the V beta amino acids. The results showed that the efficient neutralization of transmembrane proteolytic targeting information required associations between membrane spanning domains and the presence of receptor ectodomains. Interactions between receptor ectodomains may slow the dissociation of CD3 subunits from the beta chain and prolong the masking of transmembrane targeting information. In addition, the close proximity of TCR and CD3 ectodomains within the ER may provide steric protection from the action of proteases within the ER lumen.

The gamma and epsilon subunits of the CD3 complex inhibit pre-Golgi degradation of newly synthesized T cell antigen receptors.

The T cell receptor for antigen (TCR) is composed of six different transmembrane proteins. T cells carefully control the intracellular transport of the receptor and allow only complete receptors to reach the plasma membrane. In an attempt to understand how T cells regulate this process, we used c-DNA transfection and subunit-specific antibodies to follow the intracellular transport of five subunits (alpha beta gamma delta epsilon) of the receptor. In particular, we assessed the intracellular stability of each chain. Our results showed that the chains were markedly different in their susceptibility to intracellular degradation. TCR alpha and beta and CD3 delta were degraded rapidly, whereas CD3 gamma and epsilon were stable. An analysis of the N-linked oligosaccharides of the glycoprotein subunits suggested that the chains were unable to reach the medial Golgi during the metabolic chase. This was supported by immunofluorescence micrographs that showed both the stable CD3 gamma and unstable CD3 delta chain localized in the endoplasmic reticulum. To study the effects of subunit associations on intracellular transport we used cotransfection to reconstitute precise combinations of subunits. Associations between stable and unstable subunits expressed in the same cell led to the formation of stable complexes. These complexes were retained in or close to the endoplasmic reticulum. The results suggested that the intracellular transport of the T cell receptor could be regulated by two mechanisms. The TCR alpha and beta and CD3 delta subunits were degraded rapidly and as a consequence failed to reach the plasma membrane. CD3 gamma or epsilon were stable but were retained inside the cell. The results also demonstrated that there was an interplay between the two pathways such that the CD3 gamma and epsilon subunits were able to protect labile chains from rapid intracellular degradation. In this way, they could seed subunit assembly in or close to the endoplasmic reticulum and allow a stable receptor to form before its transport to the plasma membrane.

N-nitrosamines in the rubber and tire industry.

Airborne N-nitrosomorpholine (0 to 27 micrograms per cubic meter) was found in two of four rubber industry factories. N-Nitrosodimethylamine was also found in two factories, but at lower levels. These findings may be relevant to the reported increased risk of certain types of cancer in rubber workers in some of the same areas where the N-nitrosomorpholine levels were highest.

Soluble human complement receptor type 1: in vivo inhibitor of complement suppressing post-ischemic myocardial inflammation and necrosis.

The complement system is an important mediator of the acute inflammatory response, and an effective inhibitor would suppress tissue damage in many autoimmune and inflammatory diseases. Such an inhibitor might be found among the endogenous regulatory proteins of complement that block the enzymes that activate C3 and C5. Of these proteins, complement receptor type 1 (CR1; CD35) has the most inhibitory potential, but its restriction to a few cell types limits its function in vivo. This limitation was overcome by the recombinant, soluble human CR1, sCR1, which lacks the transmembrane and cytoplasmic domains. The sCR1 bivalently bound dimeric forms of its ligands, C3b and methylamine-treated C4 (C4-ma), and promoted their inactivation by factor I. In nanomolar concentrations, sCR1 blocked complement activation in human serum by the two pathways. The sCR1 had complement inhibitory and anti-inflammatory activities in a rat model of reperfusion injury of ischemic myocardium, reducing myocardial infarction size by 44 percent. These findings identify sCR1 as a potential agent for the suppression of complement-dependent tissue injury in autoimmune and inflammatory diseases.

Transportation capacity for patients with highly infectious diseases in Europe: a survey in 16 nations.

Highly infectious diseases (HIDs) are defined as being transmissible from person to person, causing life-threatening illnesses and presenting a serious public health hazard. In most European Union member states specialized isolation facilities are responsible for the management of such cases. Ground ambulances are often affiliated with those facilities because rapid relocation of patients is most desirable. To date, no pooled data on the accessibility, technical specifications and operational procedures for such transport capacities are available. During 2009, the 'European Network for HIDs' conducted a cross-sectional analysis of hospitals responsible for HID patients in Europe including an assessment of (a) legal aspects; (b) technical and infrastructure aspects; and (c) operational procedures for ground ambulances used for HID transport. Overall, 48 isolation facilities in 16 European countries were evaluated and feedback rates ranged from 78% to 100% (n = 37 to n = 48 centres). Only 46.8% (22/47) of all centres have both national and local guidelines regulating HID patient transport. If recommended, specific equipment is found in 90% of centres (9/10), but standard ambulances in only 6/13 centres (46%). Exclusive entrances (32/45; 71%) and pathways (30/44; 68.2%) for patient admission, as well as protocols for disinfection of ambulances (34/47; 72.3%) and equipment (30/43; 69.8%) exist in most centres. In conclusion, the availability and technical specifications of ambulances broadly differ, reflecting different preparedness levels within the European Union. Hence, regulations for technical specifications and operational procedures should be harmonized to promote patient and healthcare worker safety.

A genetic analysis of hermaphrodite, a pleiotropic sex determination gene in Drosophila melanogaster.

Sex determination in Drosophila is controlled by a cascade of regulatory genes. Here we describe hermaphrodite (her), a new component of this regulatory cascade with pleiotropic zygotic and maternal functions. Zygotically, her+ function is required for female sexual differentiation: when zygotic her+ function is lacking, females are transformed to intersexes. Zygotic her+ function may also play a role in male sexual differentiation. Maternally, her+ function is needed to ensure the viability of female progeny: a partial loss of her+ function preferentially kills daughters. In addition, her has both zygotic and maternal functions required for viability in both sexes. Temperature sensitivity prevails for all known her alleles and for all of the her phenotypes described above, suggesting that her may participate in an intrinsically temperature-sensitive process. This analysis of four her alleles also indicates that the zygotic and maternal components of of her function are differentially mutable. We have localized her cytologically to 36A3-36A11.

The availability of cortisol in amniotic fluid to the fetus and chorionic and amniotic membranes.

This study examined whether cortisol, present in amniotic fluid (AF), could reach the fetal blood, and might be available to various fetal organs and to the fetal membranes and placenta. [3H]Cortisol ([3H]F) was injected into the AF of five sheep at 130--143 days gestation. Samples of AF and fetal blood were collected for 120 min, at which time the fetuses were delivered and fetal organs and fluid were collected for measurement of the [3H]F content. [3H]F disappeared from AF with an initial half-life of about 40 min and was detected in fetal blood by 30 min after intraamniotic injection. At 120 min after injection, [3H]F was widely distributed within the pregnant uterus, and the highest concentrations of radioactivity were found in allantoic fluid, fetal membranes, and placental tissue. The concentration of [3H]F in the umbilical vein was higher than in umbilical arterial blood in four of five sheep. [3H]F and [3H]cortisone were found in several fetal tissues, including adrenal, kidney, pancreas, lung, and liver. [3H]F in tracheal and stomach fluid was generally less than in fetal blood. We conclude that 1) cortisol can reach the fetus from AF, 2) a major route of entry may be via the vasculature of the fetal membranes, 3) a considerable proportion of [3H]F is retained by the fetal membranes, and 4) interconversion of [3H]F and [3H]cortisone may occur in some fetal tissues.

The fetal membranes as a possible source of progesterone in the amniotic and allantoic fluids of pregnant sheep.

To assess the possible source of progesterone in the fetal fluids of pregnant sheep, we measured the changes in progesterone concentrations in amniotic fluid (AF) and allantoic fluid (ALF) during pregnancy and compared these values with those in the maternal and fetal circulations. In acute experiments, the concentration of progesterone in ALF was greater than that in AF, and in both compartments, progesterone rose progressively between day 50 of pregnancy and term (day 145). In contrast, in maternal peripheral and uterine venous blood as well as in umbilical cord blood the mean concentration of progesterone increased until day 130, but fell at term. Similar results were obtained in chronically catheterized sheep during late pregnancy. The pattern of progesterone change in the AF and ALF suggested that the steroid might originate from a different source than progesterone in the vascular compartments. By means of in vitro incubation studies, we showed that the chorioallantoic membrane and amnion from sheep at term pregnancy had the capacity to convert [3H]pregnenolone to [3H]progesterone. These results raise the possibility that there may be local changes in steroid hormone concentrations within the tissues and fluids of the pregnant uterus. These changes could be of importance in altering the intrauterine endocrine milieu at the time of birth.

Characterization of monoclonal antibodies specific for the V beta 3 family of the human T cell receptor generated using soluble TCR beta-chain.

A soluble, recombinant form of the human T cell receptor (TCR) beta-chain containing the V beta 3.1 sequence has been constructed, expressed in Chinese hamster ovary cells, amplified by dihydrofolate reductase selection, and purified in quantities appropriate for the generation of monoclonal antibodies (mAb). The V beta 3 sequence was chosen because of its reported elevated usage in the synovial T cells of rheumatoid arthritis patients but the approach described should be applicable to other known human V beta gene sequences. By this method, two mAb were prepared which reacted with up to 10% of normal, live peripheral blood T cells but with reactivity varying greatly among individual donors. Both mAb specifically bound to a murine T cell line transfected with a human TCR V beta 3.1 and immunoprecipitated a protein of the expected molecular weight for the TCR beta-chain. Both antibodies were mitogenic for T cells and analysis of peripheral blood lymphocyte cultures stimulated with the mAb suggested that both were specific for the V beta 3.1 subfamily and not D beta or J beta. Clones expressing V beta 3, which were derived from mAb-stimulated peripheral blood lymphocytes of a single individual, preferentially (8/13), but not exclusively, utilized the J beta 2.7 gene segment. The V beta 3.1 usage showed no preference for the CD8+ or CD4+ subpopulations of normal peripheral blood T cells.

Occurrence of prosaposin as a neuronal surface membrane component.

Prosaposin is a precursor of four saposins that are required for the lysosomal hydrolysis of sphingolipids by specific hydrolases. Besides its precursor role, prosaposin also exists as a secreted protein. The present investigation reveals that prosaposin also exists as an integral component of the surface membranes of neuronal cells. Subcellular fractionation studies demonstrate that the membrane-bound prosaposin occurs specifically in plasma membranes of NS20Y rat neuroblastoma cells. An immunohistochemical study of the neuroblastoma cells using rat prosaposin-specific antibodies also showed that a portion of prosaposin is located on the surface of neurites as well as on cell bodies. Similar histochemical studies with antibodies that specifically recognized human prosaposin revealed the presence of prosaposin in dendrites, axons, and cell bodies of subcortical and spinal cord neurons in both human adult brain and in fetal brain (24-wk gestation). These findings suggest an important role of prosaposin in neuronal development.

The current status of faculty staffing and resident training in emergency radiology. Results of a survey.

The results of a survey of United States and Canadian radiology residency programs in hospitals maintaining major emergency departments indicate that (1) radiologic faculty assignment to emergency medicine may include "all faculty," "specific faculty," "specific and other faculty," "general," and "musculoskeletal" faculty; (2) a chief of emergency radiology section is designated in less than 35% of radiology departments providing emergency room services; (3) radiology resident rotation in emergency radiology occurs in less than 2/3 of the surveyed programs; and (4) radiology resident experience in emergency radiology ranges from two to 16 weeks in 40% of these programs, the remainder being "unspecified." The effect of this circumstance upon the emergency department patient care and resident teaching in emergency radiology is discussed and remedial suggestions presented.

Combined light and electron microscope in routine histopathology.

We report our experience with a prototype combined light and electron microscope (the LEM 2000) with particular reference to its application to routine surgical histopathology. We found its major advantages over conventional transmission electron microscopies were due to the large grid size (7 mm diameter), low magnification capacity (x 250), and the built-in microprocessor for recording areas of interest. These features combine to reduce sampling errors and greatly facilitate orientation and relocation of fields of diagnostic importance.

A fetoscopic method for enucleation in developmental studies of the visual system.

Prenatal enucleation is accomplished by fetoscopy using an arthroscope and a needle for the delivery of electric current into the uterus of anesthetized, pregnant cats. Under direct vision, the eye(s) of the fetus are easily discerned and can readily be lesioned by the application of an electrical current delivered through the needle. The procedure is relatively simple to perform, minimizes uterine trauma and therefore postsurgical recovery times for the mother cat, enhances the prolongation of pregnancy and allows a shorter operating time for accomplishing the enucleation than does normal surgical invasion. It should be possible to make other uses of the approach, such as prenatal ocular injection of dyes or of tracer substances in place of the enucleation.

Microcomputers and database software for monitoring quality assurance activities.

A description of how one community hospital implemented a successful quality assurance program in radiology with the use of a personal computer and relational database management software is presented. The system has been well received and is easy to use and maintain. There are aspects of quality assurance beyond the double-reading method that are not addressed by this system. However, as we learn more about different quality assurance programs, the system has the capacity to evolve. The advertising literature is flooded with information about software packages that claim to meet all Joint Commission quality assurance requirements. Therefore, it is prudent to avoid making hasty purchasing decisions to accomplish a quick-fix solution to managing quality assurance activities. The Joint Commission recommends a systematic approach to defining needs and evaluating vendor products or services.