Evolution of coherence singularities in polarization singular beams

The evolution of correlation singularities in partially coherent polarization singular beams (PC-PSBs) is investigated. Since PSBs are the superposition of two orthogonally polarized vortex beams, the occurrence of coherence singularities in PC-PSBs is strongly governed by the topological charge of the component vortex beams and the spatial coherence length. Coherence singularities appear in the form of ring dislocations in the modulus of the spectral degree of coherence (SDoC) profile, and the number of ring dislocations is equal to the higher value of the topological charge of the superposing vortex beam. Furthermore, the SDoC phase profile can be used to determine the polarity of a PC-PSB. The findings of the study could be valuable in various applications that rely on the spatial coherence of beams, such as free-space communication and imaging.

Fano Resonance-Assisted All-Dielectric Array for Enhanced Near-Field Optical Trapping of Nanoparticles

Near-field optics can overcome the diffraction limit by creating strong optical gradients to enable the trapping of nanoparticles. However, it remains challenging to achieve efficient, stable trapping without heating and thermal effects. Dielectric structures have been used to address this issue but usually offer weak trap stiffness. In this work, we exploit the Fano resonance effect in an all-dielectric quadrupole nanostructure to realize a 20-fold enhancement of trap stiffness, compared to the off-resonance case. This enables a high effective trap stiffness of 1.19 fN/nm for 100 nm diameter polystyrene nanoparticles with 4.2 mW/μm2 illumination. Furthermore, we demonstrate the capability of the structure to simultaneously trap two particles at distinct locations within the nanostructure array.

Toxoplasma gondii in lactating animals: potential risk to milk consuming population in Khyber Pakhtunkhwa

Toxoplasma gondii is an intracellular zoonotic protozoan parasite usually infects human and animal worldwide. This study aimed to analyze the sero-prevalence of T. gondii in blood of lactating animals and human living in close proximity and also to detect Toxoplasma DNA in unpasteurized milk of the studied animals. A total of 233 blood and milk samples were collected from lactating animals, and 735 blood samples were taken from humans in District Upper Dir, Khyber Pakhtunkhwa, Pakistan. The blood samples were analyzed through ELISA while the milk samples were analyzed by PCR for the presence of T. gondii DNA. A standard questionnaire was introduced to collect the data from the participants. In animals, the reported sero-prevalence was 32.18% for IgM, 17.16% for IgG, and 6.4% for both IgM and IgG. The reported positivity for T. gondii DNA in milk was 14.44%, 34.8%, 20%, and 26% in sheep, goats, cows, and buffaloes, respectively. In the human blood samples, 9.8% were found positive for IgM and 11.2% for IgG while none of the samples was found positive for both IgM and IgG. Overall sero-prevalence reported in females was significantly higher than the male (p<0.05) poor hygiene condition (p < 0.0001) were the significant risk factors associated with T. gondii infections in animals. In conclusion, T. gondii infection is prevalent in lactating animals and humans using their raw milk in the study area. It is suggested that raw milk should be considered as a vehicle for the transmission of T. gondii to humans. Proper pasteurization of milk is very useful in limiting the transmission of infection. Awareness and control programs should be implemented to prevent the infection.

Burden and distribution of dengue infection in Pakistan (2000-19): a review

The goal of this study is to review the overall prevalence, burden, and distribution of the dengue disease in Pakistan from 2000 to 2019. Literature was searched using different search engines like Google scholar, PubMed, etc. providing the keywords "Dengue disease/infection, Dengue virus, DENV, DF/DHF/ DSS Pakistan". All the published research papers/reports on the dengue virus over the period 2000 to 2019 were studied and selected data were summarized using MS Excel for windows such as total cases, age wise, gender, DENV serotype distribution, total DHF, and DSS patients. The literature providing insufficient data was excluded. The total number of cases reported during 2000-19 were 201,269. The maximum number of cases during the mentioned literature survey period was reported in Khyber Pakhtunkhwa (KP) (23.3%) followed by Punjab (3.8%) and Sindh (1.9%). The majority of dengue-infected cases were reported as Dengue fever (74.4%) followed by DHF (24.1%) and DSS (1.5%). Overall the deaths during the mentioned literature survey were 1082, of which the maximum mortalities were reported from KP (N=248) followed by Punjab (N=220). DENV remains a major public health problem in Pakistan and seems to remain endemic for a long time. The total prevalence of dengue infection is increased accordingly with time from 2000 to 2019. Moreover, all the four serotypes exist in Pakistan with increased mortalities.

Coherence-induced depolarization effects in polarization singular beams

We demonstrate theoretically and experimentally coherence-induced depolarization effects in generic and higher index polarization singular beams endowed with C-point (or V-point) polarization singularity. The irradiance profiles and degree of polarization (DoP) distributions are found to be governed by spatial coherence length, polarization singularity index, and orbital angular momentum (OAM) of the superposition states of the beams. On reducing the coherence length, the DoP distribution in the V-point deteriorates uniformly. In contrast, C-point beams resist depolarization exhibiting anti-depolarization around the central core of the beam due to the nonzero net OAM of the beam. Interestingly, the polarization vortex structure remains preserved on reducing the spatial coherence length.

Investigation of partially coherent vector vortex beams with non-isotropic states of spatial correlation

In this work, the far-field properties of non-isotropic partially coherent vector vortex beams (PCVVBs) are investigated both theoretically and experimentally. The term non-isotropic signifies that the spatial correlations between the parallel and orthogonal electric field components are distinguishable. It is found that self-orientation and shaping of intensity profile, correlation-induced polarization and depolarization are highly dependent on both the non-isotropic correlation parameters and Poincaré-Hopf index (PHI) of the beam. The simultaneous depolarization and polarization effects are due to the difference in the input correlation parameters that alter the state of polarization (SOP) and degree of polarization (DOP) distributions. The experimental results are in good agreement with the theoretical predictions. The distinguishability of correlation parameters at the source plane leads to significant changes on its intensity profile, DOP, and SOP distributions on far-field propagation, which may found potential applications in beam shaping, detecting and imaging atmospheric lidar, optical imaging and directional transportation where the self-rotation characteristic of beam plays an important role.

Molecular detection and prevalence of Rotavirus with acute gastroenteritis among the children of rural and urban areas

Rotavirus is the main infective agent of acute gastroenteritis (AGE) in children under the age of five years and causing significant morbidity as well as mortality throughout the world. The study was carried out to detect the prevalence rate, genotypes strain and risk factors of Rotavirus among the children of rural and urban areas of district Bannu Khyber Pakhtunkhwa Pakistan. A total of 180 stool samples were collected from children under the age of 5 years from two major hospitals of Bannu from January to December (2015). The samples were analyzed by Reverse-transcriptase Polymerase Chain Reaction (RT-PCR) for the detection of Rotavirus, positive samples were further processed for genotyping (G and P type) through specific PCR. Of the total, 41 (23%) samples were positive for Rotavirus. The most prevalent G genotypes found were: G3, G8, G9 (each 29%), followed by G10 (15%), and G11 (10%). Whereas the prevalent P genotypes were: P-8 (25%), P-4 and P-10 (each 20%), P-9 (15%), followed by P-6 and P-11 (each 10%). Moreover, Rotavirus infection was more prevalent in summer (23.73%) and winter (22.7%) than spring (20%) and autumn (21.4%). Rotavirus infection exhibited high frequency in June (14%), October (8%) and November (6%). It is concluded that Rotavirus is more prevalent in children and various genotypes (G and P) of Rotavirus are present in the study area. Lack of studies, awareness and rarer testing of Rotavirus are the principal reasons of virus prevalence in district Bannu, Pakistan.

Young's double-slit experiment with vector vortex beams

In this Letter, Young's double-slit experiment with vector vortex beams is investigated. We present the results for various Poincaré-Hopf index beams of this class considering all four major types. Polarization associated morphological changes in the far-field interference pattern are studied both theoretically and experimentally. The Fraunhofer pattern consists of lattices of polarization singularities of the generic type, located on a line, in a direction perpendicular to the slit. The number of linear lattices varies as a function of Poincaré-Hopf index η of the beam that is diffracted, and the number of intensity nulls occurring along the vertical line is equal to |η|.

Population distribution and habitat analysis of Rufous treepie (Dendrocitta vagabunda) in Abbottabad, Pakistan

The Rufous treepie (Dendrocitta vagabunda) belongs to family corvidae, order Passeriformes which includes about 100 species. The current study was conducted to gather information about the Population distribution and habitat analysis of D. vagabunda at District Abbottabad, Pakistan. The data were collected on monthly basis both morning and evening times (2018-2019). "The ''Point count Method" was used for population estimation and ''Quadrates Method" for habitat analysis of study area. The result shows an average month-wise population density of D. vagabunda was maximum at Jhangra 0.14±0.039/ha, whereas minimum at Havelian 0.11±0.022/ha. There was no significant difference (p>0.05) among monthly population densities of D. vagabunda, however, a significant difference (p<0.05) was found between morning and evening times population of the specie. The present study revealed that importance value index (IVI) of plants species at Sherwan, Bakot, Havelian, Langra and Jhangra were 59.6±12.6, 50.1±6.9, 53.4±6.3, 66.8±10 and 60.1±7.7. Likewise, the frequency of shrubs at Sherwan, Bakot, Havelian, Langra and Jhangra were 33.3±4.2, 45±9.4, 46.7±8.2, 55.6±22.2 and 37.5±8.5. Similarly, the frequency of herbs at Sherwan, Bakot, Havelian, Langra and Jhangra were 40.4±6.0, 37.5±5.6, 53.3±7.4, 48.5±5.2 and 46.9±7.4 respectively. Our results show the study area as suitable habitat for D. vagabunda.

Comparison of different diagnostic modalities for isolation of Mycobacterium Tuberculosis among suspected tuberculous lymphadenitis patients

Tuberculosis is a communicable disease with high morbidity and mortality rates in developing countries. The study's primary objective is to compare conventional methods such as acid-fast bacillus (AFB) culture and microscopy with rapid diagnostic methods. The secondary objective is to compare histopathological and microbiological findings in suspected patients with tubercular lymphadenitis. A total of 111 samples (August 2018 to September 2019) of lymph nodes were processed for AFB microscopy, AFB cultures, drug-susceptibility testing (DST), histopathology, and Xpert Mycobacterium Tuberculosis (MTB)/resistance to Rifampin (RIF) assays. Out of 111 lymph node samples, 6 (5.4%) were positive for AFB smear microscopy, 84 (75.6%) were positive for AFB culture, 80 (70.7%) were positive on Gene Xpert, and 102 (91.8%) were indicative of tuberculosis for histopathology studies. Mycobacteria growth indicator tube (MGIT) culture positivity was 84 (75.6%) higher than solid Lowenstein-Jensen (LJ) culture 74 (66.6%). Positive cultures underwent phenotypic DST. Two cases were Multidrug-resistant (MDR) on DST, while three cases were Rifampicin resistant on Gene Xpert. The sensitivity of Genexpert was (62%) against the conventional AFB culture method. The poor performance of conventional lymphadenitis diagnostic methods requires early and accurate diagnostic methodology. Xpert MTB/RIF test can help in the treatment of multidrug-resistant TB cases. Nonetheless, rapid and conventional methods should be used for complete isolation of Mycobacterium tuberculosis.

Current trends of Hepatitis C virus genotypes and associated risk factors in hemophilia patients in Pakistan

Hemophilia is a rare bleeding disorder that needs plasma or clotting factor concentrate transfusion. Therefore chances of blood-borne pathogens like HCV transmission increase due to high prevalence in healthy donors. This study was aimed to determine the prevalence of HCV genotypes and associated risk factors in hemophilia patients of Khyber Pakhtunkhwa, Pakistan. Blood samples and data were collected from 672 hemophiliacs after proper consent obtained from each patient. Samples were analyzed for anti-HCV, HCV RNA and HCV genotype/s detection. Of the total, 22.32% (150) were anti-HCV positive, of which HCV RNA was detected in 18.45% (124) individuals. HCV genotype 3a was found with significantly higher prevalence (p<0.05) (19.35%) as compared to 2a (16.13%) and 1a (12.90%). HCV-3b and HCV-4 were found each in 3.22% samples. Dual infection of genotypes was found in 22.58% of individuals and 22.58% HCV RNA positive sampels were not typed. A total of 572 (85.12%) subjects had hemophilia A and 100 (14.88%) had hemophilia B. In hemophiliacs A the most dominant genotype was 3a (19.27%) while in hemophilia B, genotype 1a was prevalent (26.67%). Whole blood and plasma transfusion were observed as the main risk factors of HCV. It is concluded that HCV genotype 3a and 2a are prevalent in hemophilia patients of Khyber Pakhtunkhwa Pakistan and the main risk factor observed was an unscreened whole blood transfusion.

Detection of degenerate Stokes index states

Stokes phase is the phase difference between orthogonal component states in the decomposition of any polarization state. Phase singularities in the Stokes phase distribution are Stokes singularities of an inhomogeneous polarization distribution. Under circular decomposition, Stokes phase distribution \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\phi _{12})$$\end{document}(ϕ12) represents polarization azimuth \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$(\gamma )$$\end{document}(γ) distribution and the singularities present in it are polarization singularities. Therefore, the charge of the Stokes vortices depicted as Stokes index \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sigma _{12}$$\end{document}σ12 is an important parameter associated with the polarization singularity. The Hybrid order Poincaré sphere (HyOPS)/Higher order Poincaré sphere (HOPS) beams, all having same Stokes index, contain a Stokes singularity at the center of the beam as these beams are constructed by vortex superposition. These beams, being superposition of orthogonal orbital angular momentum (OAM) states in orthogonal spin angular momentum (SAM) states can offer great multiplexing capabilities in communication. In this article, we identify these degenerate Stokes index states and discuss the ways and means of lifting this degeneracy. Otherwise, there are limitations on intensity based detection techniques, where demultiplexing or segregation of different HOPS/HyOPS beams is warranted. The method adduced here uses the diffraction of these beams through an equilateral triangular aperture in combination with polarization transformation as a probe to lift the Stokes index/Stokes phase degeneracy. Successively, the novelty of the detection scheme is discussed in the context of beams with alike polarization distributions where even the technique of Stokes polarimetry fails to predict the OAM and SAM content of the beam.

Coherence-induced polarization effects in vector vortex beams

We demonstrate theoretically and experimentally coherence-induced polarization changes in higher-order vector vortex beams (VVBs) with polarization singularity. The prominent depolarization on decreasing the transverse correlation width in a focused partially coherent VVB provides a means to shape the intensity profile and degree of polarization (DOP) while preserving the polarization distribution. The intensity variation and DOP dip are found to be dependent on the polarization singularity index of the beam. Our results may provide an additional degree of freedom in myriad applications presently projected with VVBs.

Helicity conservation in V-point diffraction

In singular beams, topological charge is conserved during diffraction. Like scalar field diffraction, in vector field diffraction also, there are conserved quantities. A diffracting V-point disintegrates into a number of C-points of the same polarity in which the polarization singularity index is conserved. In this Letter, we show for the first time, to the best of our knowledge, that apart from the index, the helicity (handedness) is also conserved in V-point diffraction. Since V-point is devoid of any handedness, the helicity conservation entails that there is an equal number of opposite handed C-points in the diffracted field, which are interestingly also found to be orthogonal pairs. Further, coexistence of C-points of opposite handedness in the diffraction demands the presence of L-line, which is also shown. We experimentally demonstrate these by studying the diffraction phenomenon through two different types of apertures.

Revision of an infected total hip arthroplasty: the need for the adjustment of risk in bundled payment models for revision arthroplasty

AIMS

The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA.

PATIENTS AND METHODS

This was a retrospective review of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, between 2012 and 2017, using Current Procedural Terminology (CPT) codes for patients undergoing a revision THA (27134, 27137, 27138). International Classification of Diseases Ninth Revision/Tenth Revision (ICD-9-CM, ICD-10-CM) diagnosis codes for infection of an implant or device were used to identify patients undergoing an infected revision THA. CPT-27132 coupled with ICD-9-CM/ICD-10-CM codes for infection were used to identify patients undergoing a two-stage revision. A total of 13 556 patients were included; 1606 (11.8%) underwent a revision THA due to infection and there were 11 951 (88.2%) aseptic revisions.

RESULTS

Patients undergoing an infected revision had a significantly greater length of stay of more than three days (p < 0.001), higher odds of any 30-day complication (p < 0.001), readmission within 30 days (p < 0.001), 30-day reoperations (p < 0.001), and discharge to a destination other than the patient's home (p < 0.001).

CONCLUSION

The findings suggest the need for enhanced risk adjustment based on the indication of revision THA prior to setting prices in bundled payment models of total joint arthroplasty. This risk adjustment should be used to reduce the chance of financial disincentives in clinical practice. Cite this article: Bone Joint J 2019;101-B:547-551.

Vitamin E protects rat mesenchymal stem cells against hydrogen peroxide-induced oxidative stress in vitro and improves their therapeutic potential in surgically-induced rat model of osteoarthritis

OBJECTIVE

Oxidative stress is a major obstacle against cartilage repair in osteoarthritis (OA). Anti-oxidant agents can play a vital role in addressing this issue. We evaluated the effect of Vitamin E preconditioning in improving the potential of mesenchymal stem cells (MSCs) to confer resistance against oxidative stress prevailing during OA.

METHODS

Vitamin E pretreated MSCs were exposed to oxidative stress in vitro by hydrogen peroxide (H₂O₂) and also implanted in surgically-induced rat model of OA. Analysis was done in terms of cell proliferation, apoptosis, cytotoxicity, chondrogenesis and repair of cartilage tissue.

RESULTS

Vitamin E pretreatment enabled MSCs to counteract H₂O₂-induced oxidative stress in vitro. Proliferative markers, proliferating cell nuclear antigen (PCNA) and Ki67 were up-regulated, along with the increase in the viability of MSCs. Expression of transforming growth factor-beta (TGFβ) was also increased. Reduction of apoptosis, expression of vascular endothelial growth factor (VEGF) and caspase 3 (Casp3) genes, and lactate dehydrogenase (LDH) release were also observed. Transplantation of Vitamin E pretreated MSCs resulted in increased proteoglycan contents of cartilage matrix. Increased expression of chondrogenic markers, Aggrecan (Acan) and collagen type-II alpha (Col2a1) accompanied by decreased expression of collagen type-I alpha (Col1a1) resulted in increased differentiation index that signifies the formation of hyaline cartilage. Further, there was an increased expression of PCNA and TGFβ genes along with a decreased expression of Casp3 and VEGF genes with increased histological score.

CONCLUSION

Taken together results of this study demonstrated that Vitamin E pretreated MSCs have an improved ability to impede the progression of OA and thus increased potential to treat OA.

Selective excitation of higher-order modes in etched gelatin-coated few-mode fiber and demonstration of high relative humidity measurement

We report here our experimental studies on efficient excitation of higher-order modes in a few-mode fiber realized through selective chemical etching of single-mode fiber, depositing a dynamic refractive index profile coating (gelatin) and designing a well-performing high relative humidity (RH) (73%-99% RH) sensor with sensitivity as high as ∼1.2  dBm/% RH and fast response (∼125  ms). The design relies on fixing quasi-adiabatic transition of the single-mode-few-mode-single-mode configuration to launch light at angles corresponding to desired higher-order modes, pushing more power into the coating. Our systematic study using the devised hybrid theoretical ray- and wave-optic model uniquely interprets the variety of experimental results.

Single all-optical platform for measurement of twist and transverse stress using polarization modulation in distinct dual-mode fiber placed in a Sagnac loop

We report here the experimental demonstration of measurement of both twist and transverse stress using polarization modulation in a single all-fiber circuit consisting of a single-mode fiber (SMF)/dual-mode fiber (DMF) in a Sagnac interferometer (SI) loop. The SMF-SI prototype setup is seen to be suitable for precise measurement of twist over a broad range of ±50° and transverse stress up to 5 N with a sensitivity as high as 2.85×10(6)  pW/° and 2.08×10(7)  pW/N, respectively. It is envisaged that nearly ideal operation for twist measurement can be achieved by appropriately selecting the operating domain (pretwisted Sagnac loop for practical realization of the device) and required magnitude of applied transverse stress (weight yielding maximum sensitivity). Unlike SMF-SI, a DMF assisted SI exhibits asymmetric transmittance yielding a peak shift (∼45°) in addition to falling/rising peak amplitude of effective power(∼20  μW). This key characteristic is further utilized for tunable measurement of torsion (unidirectional from -70° to 40°) while keeping the sensitivity fixed. This research problem is then analyzed on the avenue of theoretical consideration and using classical polarization optics; we have derived the Jones birefringence matrix that accurately describes the transmission behavior of the configured fiber circuit (SMF-SI and DMF-SI) for each of the three cases, namely, transverse stress, twist, and both twist and transverse stress. Series of experimental measurements for various conditions of induced birefringence (linear/circular) were performed at length, and the results were compared with those determined theoretically towards configuring a twist and stress measuring device. The study provides an understanding of the underlying physics of dual-mode interference in a Sagnac configuration experiencing linear and circular birefringence.

Polarization and propagation characteristics of switchable first-order azimuthally asymmetric beam generated in dual-mode fiber

We report here the controlled generation of a linearly polarized first-order azimuthally asymmetric beam (F-AAB) in a dual-mode fiber (DMF) by appropriate superposition of selectively excited zeroth-order vector modes that are doughnut-shaped azimuthally symmetric beams (D-ASBs). We first demonstrate continually switching polarization mode structures having an identical two-lobe intensity profile (i.e., intra-F-AAB conversion). Then, under a distinct launching state, we generate mode structures progressively toggling between the doughnut-shaped profile and two-lobe pattern having dissimilar polarization orientations (i.e., F-AAB to D-ASB conversion). Interestingly, a decentralized elliptical Gaussian beam possessing homogenous spatial polarization is obtained by enhancing the contribution of the fundamental mode (HE₁₁/LP₀₁) in selectively excited F-AAB. A smoothly varying azimuth of the input beam in this situation resulted in redistribution of transverse energy procuring a unique and exciting unconventional two-grain T-polarized beam having mutually orthogonal state of polarization (SOP). All of the above three were achieved under a given set of launching conditions (tilt/offset) of a Gaussian mode (TEM₀₀) devised with changing SOP of the input beam. A strong modulation in the output beam characteristics was also observed with the variation in propagation distance (for a fixed input SOP) owing to the large difference in propagation constants of the participating modes (LP₀₁ and one of the F-AABs). Finally, this particular study led to a design for a low-cost highly sensitive strain measuring device based on tracking the centroid movement of the output intensity pattern. Each of our experimentally observed intensity/polarization distributions is theoretically mapped on a one-to-one basis considering a linear superposition of appropriately excited LP basis modes of the waveguide toward a complete understanding of the polarization and mode propagation in the dual-mode structure.

exomeSuite: Whole exome sequence variant filtering tool for rapid identification of putative disease causing SNVs/indels

Exome and whole-genome analyses powered by next-generation sequencing (NGS) have become invaluable tools in identifying causal mutations responsible for Mendelian disorders. Given that individual exomes contain several thousand single nucleotide variants and insertions/deletions, it remains a challenge to analyze large numbers of variants from multiple exomes to identify causal alleles associated with inherited conditions. To this end, we have developed user-friendly software that analyzes variant calls from multiple individuals to facilitate identification of causal mutations. The software, termed exomeSuite, filters for putative causative variants of monogenic diseases inherited in one of three forms: dominant, recessive caused by a homozygous variant, or recessive caused by two compound heterozygous variants. In addition, exomeSuite can perform homozygosity mapping and analyze the variant data of multiple unrelated individuals. Here we demonstrate that filtering of variants with exomeSuite reduces datasets to a fraction of a percent of their original size. To the best of our knowledge this is the first freely available software developed to analyze variant data from multiple individuals that rapidly assimilates and filters large data sets based on pattern of inheritance.

Posttraumatic stress symptoms and alcohol problems: self-medication or trait vulnerability?

BACKGROUND AND OBJECTIVES

Posttraumatic stress symptoms (PTSD) and problem alcohol use (ALC) commonly co-occur, but the nature of this co-occurrence is unclear. Self-medication explanations have been forwarded, yet traits such as tendency toward negative emotionality and behavioral disconstraint also have been implicated. In this study we test three competing models (Self-Medication, Trait Vulnerability, Combined Dual Pathway) of PTSD-ALC prospectively in a college sample.

METHOD

Participants (N=659; 73% female, M age=18) provided data at college matriculation (Time 1) and 1 year later (Time 2).

RESULTS

Structural equation models showed disconstraint to meditate the path from PTSD symptoms to alcohol problems, supporting a trait vulnerability conceptualization. Findings regarding negative emotionality and self-medication were more mixed. Negative emotionality played a stronger role in cross-sectional than in prospective analyses, suggesting the importance of temporal proximity.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Self-regulation skills may be an important focus for clinicians treating PTSD symptoms and alcohol misuse disorders concurrently.

Characteristics of transverse-stress-induced phase change through a distinct dual-mode fiber in a Sagnac loop

We report here the experimental realization of a fiber-optic transverse-stress sensor devised by a dual-mode optical-fiber segment in a standard Sagnac interferometer loop. The intermodal interference of the LP01 and LP02 modes of the dual-mode fiber (DMF) configuration is analyzed theoretically in the platform of polarization transmittance of the Sagnac loop in implementing the theoretical model. Several experimental measurements for various conditions of applied birefringence are studied at length and the results are compared with those estimated theoretically toward configuring a stress-measuring device. The study provides an understanding of the underlying physics of the working of DMF interference in a Sagnac configuration.

Multiple mechanisms deregulate EZH2 and histone H3 lysine 27 epigenetic changes in myeloid malignancies

Polycomb repressive complex 2 (PRC2) is involved in trimethylation of histone H3 lysine 27 (H3K27), chromatin condensation and transcriptional repression. The silencing function of PRC2 complex is mostly attributed to its intrinsic activity for methylating H3K27. Unlike in B-cell lymphomas, enhancer of zeste homolog 2 (EZH2) mutations in myeloid malignancies are inactivating/hypomorphic. When we assessed the mutational status in myeloid malignancies (N=469 cases examined), we found EZH2 and EED/SUZ12 mutations in 8% and 3.3% of cases, respectively. In addition to mutant cases, reduced EZH2 expression was also found in 78% cases with hemizygous deletion (-7/del7q cases involving EZH2 locus) and 41% of cases with diploid chromosome 7, most interestingly cases with spliceosomal mutations (U2AF1/SRSF2 mutations; 63% of cases). EZH2 mutations were characterized by decreased H3K27 trimethylation and increased chromatin relaxation at specific gene loci accompanied by higher transcriptional activity. One of the major downstream target is HOX gene family, involved in the regulation of stem cell self-renewal. HOXA9 was found to be overexpressed in cases with decreased EZH2 expression either by EZH2/spliceosomal mutations or because of -7/del7q. In summary, our results suggest that loss of gene repression through a variety of mutations resulting in reduced H3K27 trimethylation may contribute to leukemogenesis.

Effects of transition metal substitutions on the incommensurability and spin fluctuations in BaFe2As2 by elastic and inelastic neutron scattering

The spin fluctuation spectra from nonsuperconducting Cu-substituted, and superconducting Co-substituted, BaFe(2)As(2) are compared quantitatively by inelastic neutron scattering measurements and are found to be indistinguishable. Whereas diffraction studies show the appearance of incommensurate spin-density wave order in Co and Ni substituted samples, the magnetic phase diagram for Cu substitution does not display incommensurate order, demonstrating that simple electron counting based on rigid-band concepts is invalid. These results, supported by theoretical calculations, suggest that substitutional impurity effects in the Fe plane play a significant role in controlling magnetism and the appearance of superconductivity, with Cu distinguished by enhanced impurity scattering and split-band behavior.

Paramedic-led prehospital thrombolysis is safe and effective: the East Anglian experience

INTRODUCTION

Prehospital thrombolysis has been shown to improve patient outcomes in clinical trials and this has been confirmed in the ongoing large national myocardial infarction registry (Myocardial Infarction National Audit Project; MINAP) reports. This paper describes a system to improve the delivery of prehospital thrombolysis and the associated governance requirements to gain maximum patient benefit.

METHODS

Demographic data were prospectively collected on all patients treated by the East Anglian Ambulance Trust with bolus thrombolytics for a presumed diagnosis of ST elevation myocardial infarction between November 2003 and February 2007. Survival status was determined from the NHS strategic tracing service.

RESULTS

1062 patients (mean age 64.0 years (SD 10.6), 795 men) were treated in this time period. There were 71 deaths in this group, with actuarial survival of 93.9% (SE 0.9%) at 30 days, 91.7% (SE 1.0%) at 6 months and 90.8% (SE 1.1%) at 12 months after treatment. Age and cardiac arrest were most strongly associated with mortality (both p<0.001). Twelve (1.2%) patients received thrombolysis that on review was considered inappropriate. There were no deaths in this subgroup.

CONCLUSIONS

Prehospital thrombolysis can be administered safely by ambulance staff supported by a Trust clinical support system with excellent clinical outcomes.

Clinical and cost-effectiveness analysis of an open label, single-centre, randomised trial of spinal cord stimulation (SCS) versus percutaneous myocardial laser revascularisation (PMR) in patients with refractory angina pectoris: The SPiRiT trial

Background

Patients with refractory angina have significant morbidity. This study aimed to compare two of the treatment options, Spinal Cord Stimulation (SCS) and Percutaneous Myocardial Laser Revascularisation (PMR) in terms of clinical outcomes and cost-effectiveness.

Methods

Eligible patients were randomised to PMR or SCS and followed up for exercise tolerance time (ETT), Canadian Cardiovascular Society (CCS) classification and the quality of life measures SF-36, Seattle Angina Questionnaire and the EuroQoL at 3, 12 and 24 months. Utilities were calculated using the EQ-5D and these and costs were compared between groups. The incremental cost-effectiveness ratio (ICER) per QALY for SCS compared to PMR was also calculated.

Results

At 24 months post-randomisation, patients that had SCS and PMR had similar ETT (mean difference 0.05, 95% CI -2.08, 2.18, p = 0.96) and there was no difference in CCS classification or quality of life outcomes. The difference in overall mean costs when comparing SCS to PMR was GBP5,520 (95% CI GBP1,966 to GBP8,613; p < 0.01) and the ICER of using SCS was GBP46,000 per QALY.

Conclusion

Outcomes after SCS did not differ appreciably from those after PMR, with the former procedure being less cost-effective as currently applied. Larger studies could clarify which patients would most benefit from SCS, potentially increasing cost-effectiveness.

Trial registration

Current Controlled Trials ISRCTN09648950

USH1H, a novel locus for type I Usher syndrome, maps to chromosome 15q22-23

Usher syndrome (USH) is a hereditary disorder associated with sensorineural hearing impairment, progressive loss of vision attributable to retinitis pigmentosa (RP) and variable vestibular function. Three clinical types have been described with type I (USH1) being the most severe. To date, six USH1 loci have been reported. We ascertained two large Pakistani consanguineous families segregating profound hearing loss, vestibular dysfunction, and RP, the defining features of USH1. In these families, we excluded linkage of USH to the 11 known USH loci and subsequently performed a genome-wide linkage screen. We found a novel USH1 locus designated USH1H that mapped to chromosome 15q22-23 in a 4.92-cM interval. This locus overlaps the non-syndromic deafness locus DFNB48 raising the possibility that the two disorders may be caused by allelic mutations.

Mutations of human TMHS cause recessively inherited non-syndromic hearing loss

BACKGROUND

Approximately half the cases of prelingual hearing loss are caused by genetic factors. Identification of genes causing deafness is a crucial first step in understanding the normal function of these genes in the auditory system. Recently, a mutant allele of Tmhs was reported to be associated with deafness and circling behaviour in the hurry-scurry mouse. Tmhs encodes a predicted tetraspan protein of unknown function, which is expressed in inner ear hair cells. The human homologue of Tmhs is located on chromosome 6p.

OBJECTIVE

To determine the cause of deafness in four consanguineous families segregating recessive deafness linked to markers on chromosome 6p21.1-p22.3 defining a novel DFNB locus.

RESULTS

A novel locus for non-syndromic deafness DFNB67 was mapped in an interval of approximately 28.51 cM on human chromosome 6p21.1-p22.3. DNA sequence analysis of TMHS revealed a homozygous frameshift mutation (246delC) and a missense mutation (Y127C) in affected individuals of two families segregating non-syndromic deafness, one of which showed significant evidence of linkage to markers in the DFNB67 interval. The localisation of mTMHS in developing mouse inner ear hair cells was refined and found to be expressed briefly from E16.5 to P3.

CONCLUSIONS

These findings establish the importance of TMHS for normal sound transduction in humans.

Complications of temporary and definitive external fixation of pelvic ring injuries

OBJECTIVES

To determine the incidence of complications of external fixation in pelvic ring injuries, comparing fixator use for temporary and definitive treatment.

DESIGN

Retrospective case-note review.

SETTING

A regional centre for pelvic trauma in the UK.

PATIENTS

100 consecutive patients.

INTERVENTION

All patients were treated with pelvic external fixation for a pelvic ring injury.

RESULTS

In 52 patients, external fixation was intended for use as the definitive treatment of the pelvic ring injury and was maintained for a mean duration of 60 days (17-113). In 48 patients, it was used temporarily for a mean duration of 8 days (1-20) before internal fixation of the pelvic ring. The complication rate for definitive and temporary fixators was 62 and 21%, respectively. Pin-site infection occurred in 50% of definitive fixators and 13% of temporary fixators but rarely led to more serious complications. In five patients, the definitive management was changed as a result of a complication of the external fixator. The commonest cause for revision of either fixator was aseptic pin loosening. Revision for loose pins in eight patients was associated with the use of two pins in each iliac crest rather than three.

CONCLUSIONS

The temporary use of external fixation is safe and effective, but use for definitive treatment is associated with a high rate of infection and aseptic pin loosening.

Mutations of ESPN cause autosomal recessive deafness and vestibular dysfunction

We mapped a human deafness locus DFNB36 to chromosome 1p36.3 in two consanguineous families segregating recessively inherited deafness and vestibular areflexia. This phenotype co-segregates with either of two frameshift mutations, 1988delAGAG and 2469delGTCA, in ESPN, which encodes a calcium-insensitive actin-bundling protein called espin. A recessive mutation of ESPN is known to cause hearing loss and vestibular dysfunction in the jerker mouse. Our results establish espin as an essential protein for hearing and vestibular function in humans. The abnormal vestibular phenotype associated with ESPN mutations will be a useful clinical marker for refining the differential diagnosis of non-syndromic deafness.

Long-term disability after neck injury. a comparative study

Claims for personal injury after whiplash injury cost the economy of the United Kingdom more than pound 3 billion per year, yet only very few patients have radiologically demonstrable pathology. Those sustaining fractures of the cervical spine have been subjected to greater force and may reasonably be expected to have worse symptoms than those with whiplash injuries. Using the neck disability index as the outcome measure, we compared pain and functional disability in four groups of patients who had suffered injury to the cervical spine. After a mean follow-up of 3.5 years, patients who had sustained fractures of the cervical spine had significantly lower levels of pain and disability than those who had received whiplash injuries and were pursuing compensation (p < 0.01), but had similar levels to those whiplash sufferers who had settled litigation or had never sought compensation. Functional recovery after neck injury was unrelated to the physical insult. The increased morbidity in whiplash patients is likely to be psychological and is associated with litigation.

Cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery

BACKGROUND

During aortic aneurysm surgery, cross-clamping can lead to inadequate blood supply to the spinal cord resulting in neurological deficit. Cerebrospinal fluid drainage (CSFD) may increase the perfusion pressure to the spinal cord and hence reduce the risk of ischaemic spinal cord injury.

OBJECTIVES

To determine the effect of CSFD during thoracic and thoracoabdominal aortic aneurysm (TAAA) surgery on the risk of developing spinal cord injury.

SEARCH STRATEGY

The reviewers searched the Cochrane Peripheral Vascular Diseases Group Specialised Trials Register (last searched October 2003), the Cochrane Central Register of Controlled Trials (CENTRAL) database (last searched Issue 4, 2003), MEDLINE and EMBASE, and reference lists of relevant articles. Recent conference proceedings were scanned.

SELECTION CRITERIA

Randomised trials involving CSFD during thoracic and TAAA surgery.

DATA COLLECTION AND ANALYSIS

Both reviewers assessed the quality of trials independently. One reviewer (SNK) extracted data and the other reviewer (GS) verified the data.

MAIN RESULTS

Three trials, with a total of 287 participants operated on for type I or II TAAA, were included. In the first trial of 98 patients, neurological deficits in the lower extremities occurred in 14 (30%) CSFD and 17 (33%) controls. The deficit was observed within 24 hours of the operation in 21 (68%), and from 3 to 22 days in 10 (32%). CSFD did not have a significant benefit in preventing ischaemic injury to the spinal cord. The second trial of 33 patients used a combination of CSFD and intrathecal papaverine. It showed a statistically significant reduction in the rate of postoperative neurological deficit (p = 0.039), compared to controls. Analysis was undertaken after only one third of the estimated sample size had entered the trial. In the third trial TAAA repair was performed on 145 patients. CSFD was initiated during the operation and continued for 48 hours after surgery. Paraplegia or paraparesis occurred in 9 of 74 patients (12.2%) in the control group versus 2 of 82 patients (2.7%) with CSFD (p = 0.03). Overall, CSFD resulted in an 80% reduction in the relative risk of postoperative deficits. Meta-analysis showed an odds ratio (OR) of 0.48 (0.25 to 0.92; confidence interval (CI) 95%). For CSFD trials only OR was 0.57 (0.28 to 1.17) and for intention-to-treat in CSFD only studies OR remained unchanged.

REVIEWER'S CONCLUSIONS

There are limited data supporting the role of CSFD in thoracic and thoracoabdominal aneurysm surgery for prevention of neurological injury. Further clinical and experimental studies are indicated.

Paget-Schroetter syndrome

Objective: To review current approaches to investigation and management of Paget-Schroetter syndrome (PSS).

Methods: Relevant clinical studies and reports were searched for using MEDLINE and Embase databases and cross-referenced articles. Articles were extracted using keywords by the two authors independently.

Principal findings: There is growing evidence of functional or positional anatomical defects, which lead to subtle intimal injury and a tendency for recurrence or poor outcome. Management of PSS remains controversial. Anticoagulation as a stand-alone treatment has lost favour. Active treatment with thrombolysis followed by consideration of thoracic decompression is recommended by most in the recent literature. Thrombolytic therapy appears to be a safe and efficacious method of establishing immediate patency of the axillary/subclavian vein. The timing and indications of decompression surgery are yet to be defined clearly. There are no randomized trials of treatment or management strategies in PSS.

Conclusions: Treatment of PSS remains contentious. Most authors recommend active treatment with thrombolysis followed by thoracic decompression. Multicentre randomized trials are needed.

Predictors of functional outcome in elderly patients undergoing posterior lumbar spine surgery

To ascertain the predictors of functional outcome in elderly patients undergoing posterior lumbar spinal decompression and fusion, a modified low back outcome score questionnaire survey in 83 elderly patients (49 men, 34 women) was carried out at our hospital. The average follow-up was 35.8 months (range: 22-57 months). The outcomes were as follows: excellent to good, 83%; fair, 7%; and poor, 10%. Multiple regression analysis revealed that significant predictors of unfavorable outcome included coexistence of other bone and joint degenerative disorders (p < 0.001) and history of heart disease (p < 0.01). Patients who had undergone previous lumbar surgery had significantly lower modified low back outcome score than those without previous lumbar spine surgery (p < 0.05). The modified low back outcome score questionnaire system is a reliable method in elderly patients.

A multi-center study in order to further define the molecular basis of beta-thalassemia in Thailand, Pakistan, Sri Lanka, Mauritius, Syria, and India, and to develop a simple molecular diagnostic strategy by amplification refractory mutation system-polymerase chain reaction

The spectrum of the beta-thalassemia mutations of Thailand, Pakistan, India, Sri Lanka, Mauritius and Syria has been further characterized by a multi-center study of 1,235 transfusion-dependent patients, and the mutations discovered used to assess the fidelity of a simple diagnostic strategy. A total of 44 beta-thalassemia mutations were identified either by allele-specific oligonucleotide hybridization, amplification with allele-specific primers, or DNA sequencing of amplified product. The results confirm and extend earlier findings for Thailand, Pakistan, India, Mauritius and Syria. This is the first detailed report of the spectrum of mutations for Sri Lanka. Two novel mutations were identified, codon 55 (-A) and IVS-I-129 (A-->C), both found in Sri Lankan patients. Two beta-thalassemia mutations were found to coexist in one beta-globin gene: Sri Lankan patients homozygous for the beta0 codon 16 (-C) frameshift were also homozygous for the beta+ codon 10 (C-->A) mutation. Studies of Sri Lankan, Pakistani, and Indian carriers suggest the codon 10 (C-->A) mutation is just a rare polymorphism on an ancestral allele, on which the beta0 codon 16 (-C) mutation has arisen. Each country was found to have only a few common mutations accounting for 70% or more of the beta-thalassemia alleles. A panel of primers to diagnose the majority of the mutations by the amplification refractory mutation system was developed, enabling a simple molecular diagnostic strategy to be introduced for each country participating in the multi-center study.

Demineralized bone matrix, bone morphogenetic proteins, and animal models of spine fusion: an overview

Preclinical investigations on the use of bone morphogenetic proteins (BMP) in the spine have yielded promising results. This has led to the preliminary introduction of these growth factors in controlled clinical trials. Initial data made available suggest that these differentiating factors will play a major role in the treatment of spinal disorders in the future. This article reviews key preclinical studies and their results that formed the basis for introduction into clinical trials. Non-primate and non-human primate models of spine fusion with BMP are reviewed objectively, and important issues regarding carrier, dose, and site of implantation are discussed. Finally, exciting new gene therapy research is discussed, with comments made on its applicability for the future.

Motives underlying food choice: dentists, porters and dietary health promotion

OBJECTIVE

Differences in dental decay and disease amongst socioeconomic groups are thought to derive, in part, from variations in dietary practices and differences in education. The aim of this exploratory study was to examine whether differences in motivating factors affecting food choice could be found in a comparison of two groups at very different ends of the social spectrum: dentists and porters/cleaners.

DESIGN

A convenience sample of 100 people (51 porters/cleaners and 49 dentists) working in the dental school at a university in the North West of England were approached to interview face-to-face and complete the Food Choice Questionnaire (FCQ), a previously validated measure designed to assess nine main factors relevant to peoples' food choices. A sample size of 100 was chosen because it was adequate to test validity (using a two-group Chi-square test with a 0.050 two sided significance).

RESULTS

Findings were analysed using independent sample t-test and multiple linear regression. Results indicated significant differences between porters/cleaners and dentists in terms of their motives for food choice on six of the nine FCQ factors. These included convenience (p < 0.001), natural content (p < 0.05), price (p < 0.005), familiarity (p < .0001), mood (p < 0.03) and ethical concern (p < 0.01). Porters/cleaners tended to rate the factors covenience, price, mood and familiarity more highly, whereas dentists did the same for natural content and ethical concern.

CONCLUSIONS

Awareness of the differences in motivational factors affecting food choice between different social groups is important to dental practitioners who are being taught to play an increasing role in health promotion. If dental practitioners are to partake meaningfully in such a role, it is necessary for them to be aware not only of their own motives in food selection, but also of the way in which those motives may differ from those of their clients.

Rehabilitation for limb salvage patients: kinesiological parameters and psychological assessment

Osteosarcoma is the most frequently occurring primary malignant tumor of bone, especially in adolescence. Treatment involves either limb salvage surgery or amputation with neoadjuvant chemotherapy. This review article discusses the current treatment modalities for osteosarcoma and also compares the gait patterns and psychosocial profiles of patients treated with either limb salvage surgery or amputation for osteosarcoma. Contemporary orthopedic literature on therapeutic options for osteosarcoma patients is reviewed. Background information on the basic principles of kinesiology, with emphasis on studies of gait pattern differences among patients treated with limb salvage versus amputation, is presented. Finally, several studies of the psychologic profiles of patients after these two procedures for osteosarcoma are reviewed. Trends in contemporary orthopedic literature suggest that functional outcomes, in terms of kinesiologic parameters, are comparable for patients treated with either limb salvage or amputation. Both sets of patients reported quality-of-life problems, including difficulty retaining health insurance and finding appropriate employment, social isolation, and poor self-esteem. The management of patients with osteosarcoma includes not only an individualized surgical plan for each patient but also includes awareness of the patients' psychologic and social needs after surgery.

Sudden sensorineural hearing loss after spinal surgery under general anesthesia

Two patients, ages 72 and 71, who underwent lumbar decompressive surgery for spinal stenosis, were evaluated for postoperative sudden sensorineural hearing loss (SSHL). After two uncomplicated spinal procedures, both patients developed SSHL immediately after surgery. Hearing loss was moderate to profound in these two patients. None of the patients had a significant otologic history. Nitrous oxide administration, Valsalva maneuvers during general anesthesia, and transient drops in cerebrospinal fluid pressure stemming from spinal decompression may, in some combination, lead to an implosive force on the inner ear, causing SSHL. Further causes of postlumbar surgery SSHL may include microemboli or viral infections. SSHL is a rare but possible complication after nonotologic, noncardiac bypass surgery; only 26 cases of SSHL after this surgery have been reported. We encourage the continued reporting of sudden sensorineural hearing loss after spinal surgery.

Bisphosphonate therapy in fibrous dysplasia

Fibrous dysplasia is proliferation of fibrous tissue within the bone marrow causing osteolytic lesions and pathologic fractures. Recently, second generation bisphosphonates have shown promise in the treatment of patients with fibrous dysplasia. In the current study, six patients with fibrous dysplasia were treated with either oral alone or oral and intravenous bisphosphonates. The participants were observed for changes in N-telopeptide, pain score, and radiographic changes. In the current study, the combination bisphosphonate therapy diminished pain, prevented fractures, lowered N-telopeptide values, and led to partial resolution of fibrous dysplasia lesions.

Pediatricians' attitudes towards allergy: past and present attitudes of pediatricians towards allergy

BACKGROUND

In 1971 we published a survey of pediatricians' knowledge, attitudes, and practices relative to the field of allergy. This current survey was conducted to determine how these attitudes and practices have changed over the past 27 years.

METHODS

Our survey, consisting of 17 questions, was sent to 250 board certified pediatricians in the St. Louis area. Seven of the questions were similar to those in the 1971 survey, while the other ten were new questions which we thought were pertinent to the field of allergy currently.

RESULTS

In 1971, 75% of the pediatricians felt the specialty of allergy had great or moderate importance for the practice of pediatrics compared with 99% in 1998. In 1998, the number of physicians who felt that there was at least some value to skin testing had increased from 1971, although, only 36% felt it had great value. In 1971, 23% of pediatricians performed their own skin tests compared with 3% in 1998. Nine percent indicated that they had never referred a patient to an allergist in 1971, compared with 2% in 1998. Our new questions looked at to whom respondents were more likely to refer patients with: (1) asthma (68% allergy, 27% pulmonary, 4% both), (2) urticaria (53% allergy, 41% dermatology, 2% both), (3) chronic eczema (45% allergy, 50% dermatology, 2% both), and (4) chronic sinusitis (24% allergy, 74% otolaryngology, 2% both). Older physicians placed greater importance on the field of allergy and skin testing and were more likely to refer to an allergist than physicians under the age of 40 years.

CONCLUSION

Our results indicate that although there has been significant change in 27 years, allergists must be more aggressive in developing the knowledge, attitudes, and practices of physicians relative to the field of allergy.

Advances and strategies for spinal cord regeneration

Although a cure for spinal cord injuries does not currently exist, advances have been made in the field of spinal cord regeneration. This article discusses the pathophysiology of spinal cord injury, animal models, and strategies for restoration and regeneration of the spinal cord.