Dysfunction of proprioceptive sensory synapses is a pathogenic event and therapeutic target in mice and humans with spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by a varying degree of severity that correlates with the reduction of SMN protein levels. Motor neuron degeneration and skeletal muscle atrophy are hallmarks of SMA, but it is unknown whether other mechanisms contribute to the spectrum of clinical phenotypes. Here, through a combination of physiological and morphological studies in mouse models and SMA patients, we identify dysfunction and loss of proprioceptive sensory synapses as key signatures of SMA pathology. We demonstrate that SMA patients exhibit impaired proprioception, and their proprioceptive sensory synapses are dysfunctional as measured by the neurophysiological test of the Hoffmann reflex (H-reflex). We further show that loss of excitatory afferent synapses and altered potassium channel expression in SMA motor neurons are conserved pathogenic events found in both severely affected patients and mouse models. Lastly, we report that improved motor function and fatigability in ambulatory SMA patients and mouse models treated with SMN-inducing drugs correlate with increased function of sensory-motor circuits that can be accurately captured by the H-reflex assay. Thus, sensory synaptic dysfunction is a clinically relevant event in SMA, and the H-reflex is a suitable assay to monitor disease progression and treatment efficacy of motor circuit pathology.

Sustaining aviation workforce after the pandemic: Evidence from Hong Kong aviation students toward skills, specialised training, and career prospects through a mixed-method approach.

The aviation industry is in a recession with the rapid and immense outbreak of COVID-19 under globalisation. The future young aviation professionals might suffer from a 'career shock'. This study analysed the post-pandemic career prospects for Hong Kong aviation students using mixed-method research considering specialised and licensed training. We conducted a survey (N = 101) and focus group interviews (N = 6) to investigate students' perceived impediments and potential support from the institutions. Matt-Whitney U test is used to compare the perceptual difference in the impediments, career prospects, skills required, and institutional supports between (non-)specialised training students, (non-)engineering-related students, and (non-)final-year students. The results demonstrated no significant difference between students with and without specialised training. While final-year students perceive themselves as lacking more in terms of non-technical skills than non-final-year students, students are interested in broadening their career options to include airline operations, aircraft engineering and maintenance via acquiring a variety of emerging knowledge and technical skills. Given most studies focus on the recovery pattern of the aviation industry, this study is original in considering Hong Kong aviation students' career impediments and prospects using a mixed-method approach to provide policy insights.

ALS-Associated Endoplasmic Reticulum Proteins in Denervated Skeletal Muscle: Implications for Motor Neuron Disease Pathology.

Alpha-motoneurons and muscle fibres are structurally and functionally interdependent. Both cell types particularly rely on endoplasmic reticulum (ER/SR) functions. Mutations of the ER proteins VAPB, SigR1 and HSP27 lead to hereditary motor neuron diseases (MNDs). Here, we determined the expression profile and localization of these ER proteins/chaperons by immunohistochemistry and immunoblotting in biopsy and autopsy muscle tissue of patients with amyotrophic lateral sclerosis (ALS) and other neurogenic muscular atrophies (NMAs) and compared these patterns to mouse models of neurogenic muscular atrophy. Postsynaptic neuromuscular junction staining for VAPB was intense in normal human and mouse muscle and decreased in denervated Nmd2J mouse muscle fibres. In contrast, VAPB levels together with other chaperones and autophagy markers were increased in extrasynaptic regions of denervated muscle fibres of patients with MNDs and other NMAs, especially at sites of focal myofibrillar disintegration (targets). These findings did not differ between NMAs due to ALS and other causes. G93A-SOD1 mouse muscle fibres showed a similar pattern of protein level increases in denervated muscle fibres. In addition, they showed globular VAPB-immunoreactive structures together with misfolded SOD1 protein accumulations, suggesting a primary myopathic change. Our findings indicate that altered expression and localization of these ER proteins and autophagy markers are part of the dynamic response of muscle fibres to denervation. The ER is particularly prominent and vulnerable in both muscle fibres and alpha-motoneurons. Thus, ER pathology could contribute to the selective build-up of degenerative changes in the neuromuscular axis in MNDs.

Stockinette application over a non-prepped foot risks proximal contamination.

This study sought to determine if there was an increased risk for surgical site contamination during stockinette application for a lower extremity surgery draping technique. Utilizing a simulated, sterile surgical field, stockinettes were applied over 10 cadaver lower extremities that were contaminated with non-pathogenic Escherichia coli on the foot. Of those, five specimens were then disinfected with Chloroprep and another 5 did not undergo any disinfection. All the specimens in which the stockinette was applied over a non-prepped foot showed proximal contamination. No contamination occurred in any of the specimens where the foot was disinfected. Stockinette can be a source of surgical site contamination when placed over a non-prepared foot.

Characterization of a variant of ERGIC2 transcript.

ERGIC2 (formerly known as PTX1) is a gene identified by subtractive hybridization on the basis that it is expressed in normal human prostate, but not in prostate carcinoma. It is unrelated to the gene encoding pituitary homeobox protein (Ptx1 or Pitx1), which regulates pituitary hormone gene expression. Based on sequence homology with the yeast Erv41 protein, it is suggested that the ERGIC2 protein is an endoplasmic reticulum (ER) resident protein involved in protein trafficking between the ER and Golgi intermediate compartment (ERGIC) and cis-Golgi. However, studies from our laboratory and others have shown that it may have other functions. In this study, we have identified a variant ERGIC2 transcript with a four base deletion at the junction of exons 8-9, resulting in frame shift after codon #189. As a result, a truncated protein of 215 residues (24.5 kDa) is predicted as compared with the 377-residue (42.6 kDa) wild-type (WT) protein. The truncated variant ERGIC2 protein loses 45% of the luminal domain and the transmembrane domain near the C-terminus, and this effectively abrogates its function as the ERGIC-Golgi protein transport shuttle. The variant, like the WT protein, was found to upregulate the heme oxygenase 1 gene, suggesting that it may be involved in the oxidative stress pathway.

'Information is information': a public perspective on incidental findings in clinical and research genome-based testing.

The potential for genomic incidental findings is increasing with the use of genome-based testing. At the same time approaches to clinical decision making are shifting to shared decision-making models involving both the healthcare community and the public. The public's voice has been nearly absent in discussions on managing incidental findings. We conducted nine focus groups and nine interviews (n = 63) with a broad cross-section of lay public groups to elucidate public viewpoints on incidental findings that could occur as a result of genome-based testing in clinical and research situations. Data were analyzed using qualitative content analysis. Participants wanted incidental findings disclosed to them whether or not these were clinical or research findings. Participants used different terms to define and describe incidental findings; they wanted to know that incidental findings are possible and be given a choice to learn about them. Personal utility was an important reason for disclosure, and participants believed that managing information is a shared responsibility between professionals and themselves. Broad public input is needed in order to understand and incorporate the public's perspective on management of incidental findings as disclosure guidelines, and policies are developed in clinical and research settings.

Zinc Protoporphyrin Upregulates Heme Oxygenase-1 in PC-3 Cells via the Stress Response Pathway.

Zinc protoporphyrin IX (ZnPP), a naturally occurring molecule formed in iron deficiency or lead poisoning, is a potent competitive inhibitor of heme oxygenase-1 (HO-1). It also regulates expression of HO-1 at the transcriptional level. However, the effect of ZnPP on HO-1 expression is controversial. It was shown to induce HO-1 expression in some cells, but suppress it in others. The objective of this study is to investigate the effect of ZnPP on HO-1 expression in prostate cancer PC-3 cells. Incubation of PC-3 cells with 10 µ M ZnPP for 4 h showed only a slight induction of HO-1 mRNA and protein, but the induction was high after 16 h and was maintained through 48 h of incubation. Of all the known responsive elements in the HO-1 promoter, ZnPP activated mainly the stress response elements. Of the various protein kinase inhibitors and antioxidant tested, only Ro 31-8220 abrogated ZnPP-induced HO-1 expression, suggesting that activation of HO-1 gene by ZnPP may involve protein kinase C (PKC). The involvement of PKC α , ß , δ , η , θ , and ζ isoforms was ruled out by the use of specific inhibitors. The isoform of PKC involved and participation of other transcription factors remain to be studied.

Creation of rabbit bone and soft tissue tumor using cultured VX2 cells.

BACKGROUND: To create rabbit VX2 bone tumors, it is surgically less demanding to implant VX2 cell suspensions than minced tumor fragments. A VX2 cell line that can be expanded using standard cell culture techniques might provide an unlimited supply of cells needed to create these bone tumors. Therefore, the aim of the present study was to establish a VX2 cell line and verify its tumorigenicity in an athymic mouse and rabbit animal model. MATERIALS AND METHODS: Minced VX2 tumor fragments were allowed to grow as a monolayer in 10 mL Dulbecco's modified Eagle medium/nutrient mixture F-12 (1:1) supplemented with 10% fetal calf serum and passaged multiple times. The tumorigenecity of the cultured VX2 cells were tested in athymic mice (intradermal tumor development) and in New Zealand white rabbits (bone and soft tissue tumor model). RESULTS: The VX2 cells proliferated rapidly in tissue culture flasks containing Dulbecco's modified Eagle medium/nutrient mixture F-12 medium supplemented with 10% fetal bovine serum. After reaching confluence, the VX2 cells can only be subcultured when plated at a greater density (e.g., at a dilution of 1:1). All 6 athymic mice developed tumors within 15 d of VX2 cell suspension implantation. In the rabbits, the VX2 cells were able to produce tumors in muscle tissue and in the distal femurs but not in the proximal tibia. CONCLUSIONS: VX2 cell lines can be successfully created from VX2 tumor fragments and passaged multiple times. In contrast to previous reports, the VX2 cells grown in vitro are capable of maintaining their tumorigenecity. However, successful tumor growth might depend on the initial number of cells implanted and the use of extracellular matrices for tumor proliferation.

Atorvastatin activates heme oxygenase-1 at the stress response elements.

Statins are known to inhibit growth of a number of cancer cells, but their mechanism of action is not well established. In this study, human prostate adenocarcinoma PC-3 and breast adenocarcinoma MCF-7 cell lines were used as models to investigate the mechanism of action of atorvastatin, one of the statins. Atorvastatin was found to induce apoptosis in PC-3 cells at a concentration of 1 µM, and in MCF-7 cells at 50 µM. Initial survey of possible pathway using various pathway-specific luciferase reporter assays showed that atorvastatin-activated antioxidant response element (ARE), suggesting oxidative stress pathway may play a role in atorvastatin-induced apoptosis in both cell lines. Among the antioxidant response genes, heme oxygenase-1 (HO-1) was significantly up-regulated by atorvastatin. Pre-incubation of the cells with geranylgeranyl pyrophosphate blocked atorvastatin-induced apoptosis, but not up-regulation of HO-1, suggesting that atorvastatin-induced apoptosis is dependent on GTPase activity and up-regulation of HO-1 gene is not. Six ARE-like elements (designated StRE1 [stress response element] through StRE6) are present in the HO-1 promoter. Atorvastatin was able to activate all of the elements. Because these StRE sites are present in clusters in HO-1 promoter, up-regulation of HO-1 by atorvastatin may involve multiple StRE sites. The role of HO-1 in atorvastatin-induced apoptosis in PC-3 and MCF-7 remains to be studied.

Evaluation of elution and mechanical properties of two injectable chemotherapeutic bone cements.

Chemotherapeutic bone cements can both stabilize the bone fractures as well as deliver chemotherapy agents directly to the bone metastatic site and adjacent soft tissue tumors. This study evaluated the in vitro elution and flexural properties of Vertebroplastic™ and Confidence Ultra™ bone cements (Depuy Spine Inc., Raynham, Mass., USA) containing methotrexate. In vitro elution was measured by placing bone cement specimens containing 4 different methotrexate amounts in 20 ml saline, and the methotrexate elution was measured at regular intervals for 672 h. The flexural properties of bone cement containing 2 different initial methotrexate amounts after storage in physiological saline were measured using a 3-point bending test. The drug elution rate depended on the initial methotrexate amount added and the type of bone cement used. The relationship between the initial drug amount added and the drug elution rate was not linear. Methotrexate elution decreased the flexural modulus and strength of specimens; this decrease was not proportional to the initial amount of methotrexate added. The results show that bone cements are well suited for use with chemotherapy agents. However, the elution and mechanical properties of each bone cement-drug amount combination should be thoroughly quantified in vitro before using such a combination in a clinical setting.

Robust quantum dot exciton generation via adiabatic passage with frequency-swept optical pulses.

The energy states in semiconductor quantum dots are discrete as in atoms, and quantum states can be coherently controlled with resonant laser pulses. Long coherence times allow the observation of Rabi flopping of a single dipole transition in a solid state device, for which occupancy of the upper state depends sensitively on the dipole moment and the excitation laser power. We report on the robust population inversion in a single quantum dot using an optical technique that exploits rapid adiabatic passage from the ground to an excited state through excitation with laser pulses whose frequency is swept through the resonance. This observation in photoluminescence experiments is made possible by introducing a novel optical detection scheme for the resonant electron hole pair (exciton) generation.

Brefeldin A activates CHOP promoter at the AARE, ERSE and AP-1 elements.

Brefeldin A induces apoptosis in PC-3 and MCF-7 cells at a concentration of 30 ng/ml. RT-PCR analyses showed up-regulation of CHOP/GADD153 and splicing of XBP-1 mRNA in brefeldin A-treated cells. CHOP promoter-luciferase reporter assays demonstrated activation of AARE, ERSE, and AP-1 elements of CHOP promoter by brefeldin A treatment. The activation of these elements was not affected by preincubation of cells with N-acetyl-cysteine (NAC), L: -buthionine-(S,R)-sulfoximine (BSO), and c-Jun N-terminal kinase (JNK) inhibitor (SP600125), suggesting that activation of CHOP promoter by brefeldin A may not involve oxidative stress or JNK signaling pathway. On the other hand, brefeldin A-induced apoptosis was not affected by NAC and BSO pretreatment, but was completely suppressed by JNK inhibitor pretreatment. Our results suggest that although CHOP is up-regulated by brefeldin A, it is not a major mediator of brefeldin A-induced apoptosis.

CNS injury biomechanics and experimental models.

Traumatic brain injury (TBI) and traumatic spinal cord injury (SCI) are acquired when an external physical insult causes damage to the central nervous system (CNS). Functional disabilities resulting from CNS trauma are dependent upon the mode, severity, and anatomical location of the mechanical impact as well as the mechanical properties of the tissue. Although the biomechanical insult is the initiating factor in the pathophysiology of CNS trauma, the anatomical loading distribution and the resulting cellular responses are currently not well understood. For example, the primary response phase includes events such as increased membrane permeability to ions and other molecules, which may initiate complex signaling cascades that account for the prolonged damage and dysfunction. Correlation of insult parameters with cellular changes and subsequent deficits may lead to refined tolerance criteria and facilitate the development of improved protective gear. In addition, advancements in the understanding of injury biomechanics are essential for the development and interpretation of experimental studies at both the in vitro and in vivo levels and may lead to the development of new treatment approaches by determining injury mechanisms across the temporal spectrum of the injury response. Here we discuss basic concepts relevant to the biomechanics of CNS trauma, injury models used to experimentally simulate TBI and SCI, and novel multilevel approaches for improving the current understanding of primary damage mechanisms.

New ablation techniques for atrial fibrillation and the minimally invasive cryo-maze procedure in patients with lone atrial fibrillation.

Atrial fibrillation (AF) is associated with significant morbidity and mortality. Medical management is often palliative but new ablation techniques have enabled curative approaches. Catheter-based ablation has limited success, whilst surgical approaches are widely applicable with favourable results. The minimally invasive Cryo-Maze (MICM) replicates the lesions of the Cox-Maze procedure using cryotherapy. We present our retrospective review of all Cryo-Maze procedures performed at East Carolina University, from October 2003 to January 2006, with analysis of all MICM's for lone AF, via a small right inframammary incision. A total of 41 patients (29 male, 12 female, age 61.6+/-9.7 years) with lone AF underwent an MICM as a primary operation. There were no deaths or early or late strokes. At discharge 36 patients (87.8%) were in sinus. At six weeks, this ratio had increased to 90.2% (37/41). The rate of SR continued to improve and for those out three months, the rate increased to 92.7% (38/41). At six months, 87.2% (34/39) were in SR. SR was seen in 20/23 patients with follow-up beyond one year (87.0%). In conclusion, surgical ablation techniques that replicate the Cox-Maze procedure are associated with high rates of sinus rhythm beyond one year, with wide application. AF is a curable condition, using a combination of catheter-based and surgical approaches. Newer surgical ablation devices allow minimally invasive approaches.

PTX1(ERGIC2)-VP22 fusion protein upregulates interferon-beta in prostate cancer cell line PC-3.

PTX1 is a gene identified by subtractive hybridization on the basis that it is expressed in normal prostate and not in prostate carcinoma. It is unrelated to the pituitary homeobox protein (Ptx1 or Pitx1), which regulates pituitary hormone gene expression, and its function is currently unknown. Recently, it was found to be a homolog of the yeast Erv41p, an endoplasmic reticulum (ER) resident protein involved in protein trafficking between ER and Golgi, and was renamed as ERGIC2. Ectopic expression of a partial sequence of PTX1 (Met84 - Leu225) as a VP22-fusion protein in prostate cancer cell line, PC-3, induced cellular senescence. Gene expression microarray analyses showed that interferon-beta (IFN-beta) and a number of IFN-inducible genes, among other genes, were upregulated by the PTX1-VP22 fusion protein. Upregulation of IFN-beta was confirmed by RTPCR and promoter-reporter assay. However, the upregulation of IFN-beta by the PTX1-VP22 fusion protein was not due to nuclear translocation of the PTX1 luminal domain.

Penfigoide gestacional: estudio de 9 casos / Pemphigoid gestationis: a study of 9 cases

El penfigoide gestacional es una dermatosis bullosa subepidérmica rara, que aparece generalmente en multíparas en el curso del segundo o tercer trimestre de la gestación o, eventualmente, en el posparto. El objetivo de este trabajo es determinar el perfil epidemiológico, clínico, terapéutico y evolutivo de esta afección a través de una serie hospitalaria. El estudio es retrospectivo, realizado en 9 pacientes que presentaron un penfigoide gestacional, confirmado por inmunofluorescencia directa y controladas por el servicio de dermatología. La edad de aparición de la enfermedad estaba comprendida entre 18 y 35 años, con una media ñ de 27,33 ñ 5,68 años. El primer acceso de penfigoide gestacional afectó, sobre todo, a las multíparas (77,77 por ciento de los casos) y había aparecido en el curso del tercer trimestre en 6 pacientes (66,66 por ciento).En todas las enfermas, el primer síntoma fue prurito intenso, seguido de una erupción eritematosa maculopapulosa. En el acmé del proceso, todas las mujeres presentaron máculas eritematosas confluyentes y policíclicas, rematadas por vesículas con disposición herpética, con predominio en la región umbilical. La inmunofluorescencia directa confirmó el diagnóstico en todos los casos, objetivando un depósito lineal de la fracción C3 del complemento a lo largo de la unión dermoepidérmica. La corticoterapia general (0,5-1 mg/kg/día) se utilizó en el 77,77 por ciento de los casos (7 de 9 mujeres). La dapsona fue eficaz en 2 pacientes (22,22 por ciento); 3 pacientes (33,33 por ciento) mejoraron con antihistamínicos asociados a los dermocorticoides. La evolución reflejó una recidiva de las lesiones en el posparto inmediato en 5 mujeres (55,55 por ciento); 3 mujeres presentaron recidivas en el curso de gestaciones ulteriores. El penfigoide gestacional es una dermatosis rara en el curso del embarazo. Nuestra serie se ajusta a lo reflejado en la bibliografía, con predominio de aparición en el tercer trimestre, un mayor porcentaje de multíparas y ausencia de afección en los neonatos. No obstante, es de destacar la afección relativamente alta de la cara y la eficacia de la dapsona cuando ésta fue prescrita (AU)

Rotura espontánea de los vasos uteroováricos en el posparto / Spontaneous rupture of the uterine-ovarian vessels in the postpartum

La rotura espontánea de las venas de la red uteroovárica durante la gestación y el período periparto se ha comunicado en algunas decenas de casos documentados en la bibliografía, como curiosidad médica, y es rara y excepcionalmente mencionada en los libros de obstetricia. Se trata, no obstante, de una causa dramática de pérdidas fetales y/o maternas. Se dispone de las siguientes estadísticas: el 60 por ciento de los casos está asociado al trabajo de parto y el 50 por ciento afecta a pacientes primíparas. Cuando la rotura de las venas uteroováricas está asociada al trabajo de parto, el porcentaje de mortalidad materna es del 40 por ciento. Fuera del trabajo de parto, se estima una mortalidad del 10 por ciento. La tasa de mortalidad perinatal, por lo que al proceso se refiere, oscila alrededor del 30 por ciento. En el 75 por ciento de los casos, el ligamento ancho es el punto de rotura, aunque en numerosos casos éste no puede localizarse, lo que se hace después de la laparotomía o de la autopsia. Se presenta un caso de rotura de una vena ovárica en el segundo día de puerperio (AU)

Anomalía anexial fisiológica puesta de manifiesto después de una histerosalpingografía y una laparoscopia / Physiological adnexal defect identified following hysterosalpingogram and laparoscopy during infertility evaluation

Se describe una anomalía anexial descubierta en el curso de una histerosalpingografía y de una laparoscopia en el estudio de una infertilidad. Durante un estudio de infertilidad primaria, se encuentra una anomalía de la histerosalpingografía compatible con una obstrucción tubárica derecha parcial en una paciente de 31 años sin antecedentes quirúrgicos notables. Durante la laparoscopia exploradora, el diagnóstico inicial es modificado por el descubrimiento de una abertura fisiológica ovoide de 38 × 44 mm con bordes regulares, localizada en el centro del ligamento ancho derecho, en el lugar correspondiente al defecto observado en la HSG. La lesión es explorada pero no reparada quirúrgicamente, y la permeabilidad tubárica es seguidamente confirmada por una prueba de azul de metileno. La inducción de la ovulación con inseminación intrauterina se decidió de acuerdo con la pareja y después de discutir los descubrimientos operatorios. La paciente concibió y llevó a término una gestación normal. Mientras que las anomalías de la HSG son un descubrimiento corriente en el curso de estudios de infertilidad, la aparición de anomalías peritoneales constitutivas o primitivas no se ha descrito con frecuencia. Esta clase de particularidad anatómica podría explicar ciertas anomalías de imagen observadas en la práctica clínica habitual (AU)

Embolias gaseosas y terapia por oxigenación hiperbárica durante la gestación / Uterine rupture secondary to dinoprostone in association with epidural analgesia

Aportamos el caso de una mujer embarazada que presentó una embolia paradójica gaseosa subsiguiente a la desconexión del catéter de una vía venosa central. La instalación secundaria de una hemiplejía derecha asociada con un síndrome confusional justificó el tratamiento de urgencia por oxigenoterapia hiperbárica, lo que permitió la remisión completa del cuadro neurológico inicial. La presentación de este caso clínico pone en primer plano la discusión de los riesgos de embolia gaseosa durante el embarazo y el posparto, las indicaciones y los efectos de la oxigenoterapia hiperbárica sobre el feto (AU)

Embolias gaseosas y terapia por oxigenación hiperbárica durante la gestación / Air embolism and hyperbaric oxygen therapy during pregnancy

Aportamos el caso de una mujer embarazada que presentó una embolia paradójica gaseosa subsiguiente a la desconexión del catéter de una vía venosa central. La instalación secundaria de una hemiplejía derecha asociada con un síndrome confusional justificó el tratamiento de urgencia por oxigenoterapia hiperbárica, lo que permitió la remisión completa del cuadro neurológico inicial. La presentación de este caso clínico pone en primer plano la discusión de los riesgos de embolia gaseosa durante el embarazo y el posparto, las indicaciones y los efectos de la oxigenoterapia hiperbárica sobre el feto (AU)