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  1. Reversible Posterior Leukoencephalopathy Syndrome Induced by Pazopanib

    PubMed Central

    2012-01-01

    Background The reversible posterior leukoencephalopathy syndrome is a clinical/radiological syndrome characterized by headache, seizures, impaired vision, acute hypertension, and typical magnetic resonance imaging findings. There are several reports in the literature that depict its occurrence in cancer patients. The list of common anticancer and supportive care drugs that predispose to reversible posterior leukoencephalopathy syndrome is expanding and includes not only a large number of chemotherapeutic agents but also an increased number of new targeted drugs, particularly angiogenesis inhibitors such as bevacizumab,sorefenib and sunitinib. Pazopanib is an oral tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit which after a positive phase III randomized clinical trial in patients with advanced renal cell cancer received FDA approval for the treatment of advanced renal cell carcinoma. Until now no cases of reversible posterior leukoencephalopathy syndrome induced by pazopanib have been reported. Case report We present the case of a 40 years old female patient with heavily pre-treated metastatic renal cell carcinoma who received pazopanib as salvage treatment. After 21 days of pazopanib therapy the patient referred to the emergency department with epileptic seizure, impaired vision at both eyes and headache. MRI of the brain revealed subcortical oedema at the occipital and parietal lobes bilaterally. She was treated with anticonvulsants, i.v. administration of mannitol and antihypertensives and she recovered completely from her symptoms and was discharged on the tenth hospital day. A brain MRI performed 3 weeks after showed that the subcortical oedema had been subsided. Conclusion In conclusion this is the first case of pazopanib induced reversible posterior leukoencephalopathy syndrome. Although usually reversible, this syndrome is a serious and potentially life threatening adverse

  2. Arthroscopic Reverse Remplissage for Posterior Instability.

    PubMed

    Lavender, Chad D; Hanzlik, Shane R; Pearson, Sara E; Caldwell, Paul E

    2016-02-01

    Posterior shoulder dislocation is an unusual injury often associated with electrical shock or seizure. As with anterior instability, patients frequently present with an impaction injury to the anterior aspect of the humeral head known as a "reverse Hill-Sachs lesion." The treatment of this bony defect is controversial, and multiple surgical procedures to fill the defect in an effort to decrease recurrence have been described. Most of the reports have focused on an open approach using variations of lesser tuberosity and subscapularis transfers, bone allograft, and even arthroplasty to assist with persistent instability. We advocate an arthroscopic technique that involves a suture anchor-based distal tenodesis of the subscapularis tendon or a reverse remplissage procedure. PMID:27073776

  3. Arthroscopic Reverse Remplissage for Posterior Instability

    PubMed Central

    Lavender, Chad D.; Hanzlik, Shane R.; Pearson, Sara E.; Caldwell, Paul E.

    2016-01-01

    Posterior shoulder dislocation is an unusual injury often associated with electrical shock or seizure. As with anterior instability, patients frequently present with an impaction injury to the anterior aspect of the humeral head known as a “reverse Hill-Sachs lesion.” The treatment of this bony defect is controversial, and multiple surgical procedures to fill the defect in an effort to decrease recurrence have been described. Most of the reports have focused on an open approach using variations of lesser tuberosity and subscapularis transfers, bone allograft, and even arthroplasty to assist with persistent instability. We advocate an arthroscopic technique that involves a suture anchor–based distal tenodesis of the subscapularis tendon or a reverse remplissage procedure. PMID:27073776

  4. Mycophenolate-Induced Posterior Reversible Encephalopathy Syndrome.

    PubMed

    Khajuria, Bhavik; Khajuria, Mansi; Agrawal, Yashwant

    2016-01-01

    A 29-year-old woman presented with diffuse anasarca and shortness of breath. Workup revealed a creatinine of 3.3 and a glomerular filtration rate of 17. The patient was also found to be pancytopenic with evidence of hemolytic anemia. A renal biopsy showed evidence of stage IV lupus nephritis with rapidly progressive glomerulonephritis. Her lupus was further classified as ANA negative and anti-dsDNA positive. Mycophenolate and triweekly hemodialysis were started along with a steroid burst of methylprednisolone 1 g for 3 days followed by prednisone 60 mg daily. Four days after discharge, the patient represented with a witnessed 3-minute seizure involving bowel incontinence, altered mental status, and tongue biting. She was given 2 mg intravenous lorazepam and loaded with 1000 mg levetiracetam for seizure prophylaxis. Magnetic resonance imaging of the head revealed bilateral posterior hemispheric subcortical edema, and the diagnosis of posterior reversible encephalopathy syndrome was made. Mycophenolate was immediately discontinued and replaced with cyclophosphamide. Strict blood pressure control below 140/90 mm Hg was maintained initially with intravenous nicardipine drip and then transitioned to oral nifedipine, clonidine, losartan, and minoxidil. A repeat head magnetic resonance imaging 8 days later showed resolved subcortical edema consistent with the patient's improved mental status. No permanent neurologic sequelae were recorded as a result of this hospital episode. PMID:25933141

  5. [Posterior reversible encephalopathy: beyond the original description].

    PubMed

    Avecillas-Chasín, Josué M; Matías-Guiu, Jordi A; Bautista-Balbás, Luis

    2015-07-16

    Introduccion. La encefalopatia posterior reversible (EPR) es una entidad clinicorradiologica caracterizada tipicamente por cuadros de cefalea, alteraciones visuales y crisis epilepticas, asociada a edema vasogeno corticosubcortical reversible en la neuroimagen. Objetivo. Presentar una revision de los aspectos fisiopatologicos de esta entidad y tambien de las asociaciones de la EPR descritas en la bibliografia. Desarrollo. Existe una serie de factores desencadenantes bien conocidos, como las crisis hipertensivas, la eclampsia o ciertos medicamentos. La descripcion de cada vez mas casos atipicos desde un punto de vista clinico y radiologico, asi como de posibles nuevos factores desencadenantes, obliga a una redefinicion de la entidad. Conclusiones. La EPR es un conjunto de manifestaciones clinicas y radiologicas que no se pueden enmarcar dentro la palabra 'sindrome'. Aunque la EPR se ha comunicado como irreversible en ciertos casos, el concepto de reversibilidad debe mantenerse en la definicion de esta entidad, ya que, en la mayor parte de los casos, el rapido control de la condicion desencadenante de la EPR permite la reversibilidad de las lesiones.

  6. Posterior Reversible Encephalopathy Syndrome Complicating Traumatic Pancreatitis

    PubMed Central

    Sigurtà, Anna; Terzi, Valeria; Regna-Gladin, Caroline; Fumagalli, Roberto

    2016-01-01

    Abstract We are reporting a case of posterior reversible encephalopathy syndrome (PRES) developed in an unusual clinical scenario without the presence of the most described symptoms. PRES is a neurological and radiological syndrome described in many different clinical conditions. In children it has been mostly reported in association with hematological and renal disorders. Our patient was a 15 years old boy, admitted to our intensive care unit for pancreatitis after blunt abdominal trauma. During the stay in the intensive care unit, he underwent multiple abdominal surgical interventions for pancreatitis complications. He had a difficult management of analgesia and sedation, being often agitated with high arterial pressure, and he developed a bacterial peritonitis. After 29 days his neurological conditions abruptly worsened with neuroimaging findings consistent with PRES. His clinical conditions progressively improved after sedation and arterial pressure control. He was discharged at home with complete resolution of the neurological and imaging signs 2 months later. The pathophysiology of PRES is controversial and involves disordered autoregulation ascribable to hypertension and endothelial dysfunction. In this case both hypertension and endothelial activation, triggered by sepsis and pancreatitis, could represent the culprits of PRES onset. Even if there is no specific treatment for this condition, a diagnosis is mandatory to start antihypertensive and supportive treatment. We are therefore suggesting to consider PRES in the differential diagnosis of a neurological deterioration preceded by hypertension and/or septic state, even without other “typical” clinical features. PMID:27258506

  7. Brainstem variant of posterior reversible encephalopathy syndrome: A case report.

    PubMed

    Tortora, Fabio; Caranci, Ferdinando; Belfiore, Maria Paola; Manzi, Francesca; Pagliano, Pasquale; Cirillo, Sossio

    2015-12-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological condition, generally observed in conjunction with severe and acute hypertension, that involves mainly the posterior head areas (occipital and temporal lobes) and anterior "watershed" areas. In this syndrome it is rare to observe a predominant involvement of the brainstem. We describe the clinical and radiological findings in a patient with brainstem involvement, discussing its pathophysiological features and possible differential diagnosis.

  8. Reversible posterior leukoencephalopathy syndrome in a child treated with bevacizumab.

    PubMed

    Levy, Carolyn Fein; Oo, Khine Zin; Fireman, Fernando; Pierre, Louisdon; Bania, Marita A; Sadanandan, Swayamprabha; Yamashiro, Darrell J; Glade Bender, Julia L

    2009-05-01

    Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF). Hypertension is a well-recognized, common side effect of VEGF blocking agents. The reversible posterior leukoencephalopathy syndrome (RPLS) has been described as a rare but serious consequence of bevacizumab administration. We present a case of a 6-year-old child with refractory hepatoblastoma who developed hypertensive crisis, seizures and MRI changes consistent with RPLS while receiving bevacizumab with gemcitabine and oxaliplatin. Findings completely resolved without neurologic sequelae with stringent blood-pressure control. Better understanding of risk for RPLS, prompt recognition and aggressive management will be required as bevacizumab gains wider use in pediatrics.

  9. Posterior reversible encephalopathy syndrome: the importance of early diagnosis.

    PubMed

    Teotónio, Rute; Marmoto, Dina; Januário, Cristina; Bento, Conceição

    2012-09-17

    A 14-year-old boy was submitted to cardiac transplant due to a dilated cardiomyopathy. On the fourth day of immunosuppression (corticosteroids, mycophenolate mofetil and tacrolimus), he developed right focal seizures and drowsiness. Blood pressure was in the normal range and laboratory findings in cerebral spinal fluid and blood were unremarkable, with drugs in non-toxic levels. The EEG showed a slow background rhythm more pronounced on the right and a seizure onset in the right occipital region. MRI revealed a diffuse hyperintense subcortical white-matter lesion on fluid attenuated inversion recovery, with lesser involvement of left temporal-occipital region. There was no enhancement with gadolinium and MRI diffusion-weighted imaging was consistent with vasogenic oedema. Tacrolimus was stopped with regression of MRI abnormalities and clinical recovery. Posterior reversible encephalopathy associated with tacrolimus is a rare but potentially serious complication of solid organ transplants. A prompt diagnosis and correct treatment is essential to avoid irreversible brain damage.

  10. Posterior Reversible Encephalopathy Syndrome (PRES) After Acute Pancreatitis

    PubMed Central

    Murphy, Tara; Al-Sharief, Khalid; Sethi, Vineeta; Ranger, Gurpreet S.

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an unusual condition typified by acute visual impairment caused by sudden, marked parieto-occipital vasogenic edema. Thought to be inflammatory in origin, it has been described in patients undergoing chemotherapy, with autoimmune disease, and in some infections. We report a case of PRES that occurred one week after an episode of acute pancreatitis in an otherwise healthy 40-year-old female. There was progressive visual impairment over a 24-hour period with almost complete visual loss, with characteristic findings on magnetic resonance imaging. After treatment with steroids, the visual loss recovered. Clinicians should retain an index of suspicion of this rare condition in patients with visual impairment after acute pancreatitis. PMID:26759673

  11. Posterior reversible encephalopathy syndrome secondary to blood transfusion.

    PubMed

    Singh, Karanbir; Gupta, Rajesh; Kamal, Haris; Silvestri, Nicholas J; Wolfe, Gil I

    2015-03-01

    The appearance of posterior reversible encephalopathy syndrome (PRES) after blood transfusion is rare and has only been reported in three patients to our knowledge. We report a fourth patient with PRES secondary to blood transfusion. A 36-year-old woman with a history of menorrhagia presented to the emergency department with severe fatigue. She had a hemoglobin of 1.7 g/dl and received four units of red blood cells over 15 hours. On day 6 post-transfusion she returned with confusion, headache and a generalized tonic-clonic seizure. The MRI of her brain was consistent with PRES. The following day her confusion worsened, repeat MRI of the brain showed new T2-weighted lesions. Over next 10 days her mental status gradually improved close to her baseline. A repeat MRI of the brain showed resolution of the T2-weighted lesions. The clinical presentation, radiological findings and disease progression in our patient was consistent with PRES. Other than the blood transfusions, there were no apparent risk factors for PRES. The prior three patients with post-transfusion PRES have been reported in middle-aged women with uterine fibroids. It is suspected that these patients have a subacute to chronic anemic state due to ongoing menorrhagia. It is interesting to note that no cases of PRES post-transfusion have been reported in the setting of acute blood loss, such as from trauma. It is postulated that an abrupt increase in hemoglobin causes a rapid rise in blood viscosity and loss of hypoxic vasodilation. Subsequent endothelial damage and brain capillary leakage results in PRES. This constellation of changes may not occur after transfusion in patients with more acute blood loss.

  12. Reversible posterior encephalopathy syndrome associated with micronodular adrenocortical disease and Cushing syndrome.

    PubMed

    Lodish, Maya; Patronas, Nicholas J; Stratakis, Constantine A

    2010-01-01

    We report a 6-year-old girl with ACTH-independent Cushing syndrome secondary to bilateral adrenal hyperplasia; she presented with hypertension and seizures, and magnetic resonance imaging shows changes consistent with posterior reversible encephalopathy syndrome.

  13. Blood transfusion in sickle cell disease leading to posterior reversible encephalopathy syndrome (PRES).

    PubMed

    Raj, Shashi; Killinger, James; Overby, Philip

    2013-10-01

    Children with sickle cell disease have a very high risk of lifelong neurologic morbidity and mortality. Cerebrovascular accidents are a known complication in children with sickle cell disease. Posterior reversible encephalopathy syndrome is a constellation of acute neurologic findings increasingly recognized in pediatric critical care population with evidence of vasogenic edema on brain imaging possibly due to cerebral vascular endothelial cell dysfunction. This report, for the first time, describes a young adult with sickle cell disease who developed posterior reversible encephalopathy syndrome following blood transfusion. PMID:22899796

  14. [The course of early neurological rehabilitation in a patient with severe posterior reversible encephalopathy syndrome].

    PubMed

    Gdynia, H J; Ampatzis, G; Diaconescu, A; Nowak, D A; Dabitz, R; Pfefferkorn, T

    2014-12-01

    Posterior reversible encephalopathy syndrome (PRES) is widely held to be a benign and potentially reversible disease. However, severe cases have been described in the literature. Data on the long-term outcome of these severe cases are scarce. Furthermore, there are no data focusing on potential benefits of neurological early rehabilitation in these patients. Here we present the clinical picture, neuroimaging features, rehabilitative course and long-term outcome of a patient with severe PRES who underwent early neurological rehabilitation.

  15. Reversible posterior leukoencephalopathy associated with chronic graft-versus-host disease: A case report

    PubMed Central

    YU, JINBEI; SUN, LICHAO; LIN, WEIHONG

    2016-01-01

    The present study describes the clinical manifestations, magnetic resonance imaging (MRI) features and treatments of a 22-year-old male patient diagnosed with reversible posterior leukoencephalopathy syndrome (RPLS) associated with graft-versus-host disease (GVHD) 7 months after a haploid hematopoietic stem cell transplantation. The patient was admitted to hospital after falling unconscious. Head MRI demonstrated abnormal signals in the bilateral, frontal, parietal, temporal and occipital lobes, consistent with reversible posterior leukoencephalopathy syndrome (RPLS). Based on a detailed diagnosis, the response to treatment and follow-up, it was concluded that RPLS was closely associated with chronic graft-versus-host disease in the patient. The present case report is described in order to increase the awareness of RPLS. PMID:27284340

  16. Reversible posterior leukoencephalopathy in a venomous snake (Bothrops asper) bite victim.

    PubMed

    Delgado, Miguel E; Del Brutto, Oscar H

    2012-03-01

    An 18-year-old man developed posterior reversible leukoencephalopaty after being bitten by a venomous snake (Bothrops asper). It is possible that this previously unrecognized neurological complication of snake bite envenoming occurred as the result of endothelial dysfunction induced by the venom of the offending snake. This pathogenetic mechanism has also been implicated as the cause of cerebral infarctions in snake bite victims. Alternatively, the leukoencephalopathy might have been a complication of antivenom therapy.

  17. Improvement of the Rotation Arch of the Posterior Interosseous Pedicle Flap Preserving Both Reverse Posterior and Anterior Interosseous Vascular Sources

    PubMed Central

    Tiengo, Cesare; Lombardi, Matteo; Bassetto, Franco

    2016-01-01

    Purpose: The reverse posterior interosseous artery flap has several advantages, not sacrificing any major blood vessel, but its relatively short pedicle limits the use to cover defects up to the metacarpophalangeal joint. Our purpose is to demonstrate that the ligature of the anterior interosseous artery (AIA), proximal to the communicating branch with the posterior interosseous artery, leads to an improved flap rotation arch, preserving both vascular sources. Methods: Sixteen fresh cadavers with latex perfusion were analyzed before and after our technique of elongation, and the so-obtained measures were standardized in “percentage of elongation of the pedicle.” Eight patient with the loss of substance at the dorsal aspect of the hand have been treated with this technique, and results were evaluated in terms of flap survival and complication rates. Results: The medium length of the pedicle in the normal flap was 10.8 cm, and after the section of the AIA, the medium length of the pedicle was 13.6 cm with a medium increase of 2.8 cm. It means a medium increase of 24% of the length of the pedicle. In all patients treated, full coverage of the defect was obtained, and we did not experience major complications. Conclusions: This anatomical study supported by our clinical experience demonstrates that the use of the variant described above permits to reach more distal part of the hand without being afraid to stretch the pedicle because of the connection with the anastomotic arcades of the AIA at the wrist reducing the risk of ischemia of the flap. PMID:27536473

  18. Reversible Posterior Leukoencephalopathy Syndrome Developing After Restart of Sunitinib Therapy for Metastatic Renal Cell Carcinoma

    PubMed Central

    Toyoshima, Yuta; Inoue, Takeshi; Kagebayashi, Yoriaki; Samma, Shoji

    2016-01-01

    A 64-year-old Japanese man had started molecular-targeted therapy with sunitinib for lymph node metastasis 5 years after nephrectomy for left renal cell carcinoma (clear cell carcinoma, G2, pT2N0M0). He was transported to our emergency department because of generalized tonic-clonic seizure, vision loss, and impaired consciousness with acute hypertension after 8 cycles of treatment (2 years after the initiation of sunitinib therapy, including a drug withdrawal period for one year). MRI of the brain (FLAIR images) showed multiple high-intensity lesions in the white matter of the occipital and cerebellar lobes, dorsal brain stem, and left thalamus. Reversible posterior leukoencephalopathy syndrome caused by sunitinib was suspected. In addition to the immediate discontinuation of sunitinib therapy, the administration of antihypertensive agents and anticonvulsants improved the clinical symptoms without neurological damage. Physicians should be aware that sunitinib causes reversible posterior leukoencephalopathy syndrome. The early recognition of reversible posterior leukoencephalopathy syndrome is critical to avoid irreversible neurological damage. PMID:27795711

  19. Posterior reversible encephalopathy syndrome in a child with Henoch-Schönlein purpura

    PubMed Central

    Sivrioglu, Ali Kemal; Incedayi, Mehmet; Mutlu, Hakan; Meral, Cihan

    2013-01-01

    Henoch-Schönlein purpura (HSP) is a small vessel vasculitis that affects the gastrointestinal and central nervous systems and the kidneys. The disease primarily affects children, but may occur in elderly children with allergic purpura and also in adults. Central nervous system involvement may be the first sign; however, it is rarely encountered. Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome of encephalopathy, headache, visual disturbance and seizures. Its radiological signs can be observed in grey and white matter at the posterior region of the cerebral hemispheres. HSP should be considered in children with PRES in the presence of rash, joint and gastrointestinal symptoms. We reported a 5-year-old patient who developed acute renal failure and PRES by reason of HSP. PMID:23946524

  20. Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients

    PubMed Central

    Aracki-Trenkić, Aleksandra; Stojanov, Dragan; Trenkić, Milan; Radovanović, Zoran; Ignjatović, Jelena; Ristić, Saša; Trenkić-Bozinović, Marija

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image.

  1. Atypical presentation of posterior reversible encephalopathy syndrome: Clinical and radiological characteristics in eclamptic patients.

    PubMed

    Aracki-Trenkić, Aleksandra; Stojanov, Dragan; Trenkić, Milan; Radovanović, Zoran; Ignjatović, Jelena; Ristić, Saša; Trenkić-Bozinović, Marija

    2016-08-01

    Posterior reversible encephalopathy syndrome (PRES) is an obstetric emergency frequently occurring in a pregnant or puerperal woman, manifested with an acute headache, consciousness impairment, seizures, and visual deficits and is associated with white matter changes predominantly affecting the posterior parietal and occipital lobes of the brain. Apart from the above-described typical location of the changes, the most common atypical location involves the brain stem and basal ganglia. Since magnetic resonance imaging (MRI) is more sensitive and specific imaging technique compared to computerized tomography, establishing the diagnosis and follow-up in patients with PRES is based mainly on MRI findings. It is particularly important not to exclude PRES as a possible diagnosis when we have the appropriate clinical presentation accompanied by the atypical radiological findings, since this clinical-radiological syndrome can often be manifested with an atypical MRI image. PMID:27483175

  2. An unusual case of posterior reversible encephalopathy syndrome in a patient being weaned from intrathecal morphine

    PubMed Central

    Van Aalst, Jasper; Teernstra, Onno P; Weber, Wim E; Rijkers, Kim

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity based on clinical signs, including headache, visual abnormalities, and seizures, and radiological abnormalities mostly consisting of vasogenic brain edema predominantly in the posterior parietal-temporal-occipital regions. PRES typically develops in the setting of a significant “ systemic process”, including preeclampsia, transplantation, infection/sepsis/shock, autoimmune disease, and cancer chemotherapy, in which hypertension often plays an important role. We present a case of PRES in a 63-year-old female patient with an infected intrathecal morphine pump on a cocktail of antibiotics, morphine, clonidine, diazepam, and amitriptyline. It is the first PRES case in a chronic pain patient, which illustrates that PRES can occur in the absence of any of the established risk factors. We hypothesize it may have been caused by antibiotic treatment in our patient. PMID:27274314

  3. Posterior reversible encephalopathy syndrome in a hypertensive patient with renal failure.

    PubMed

    Aatif, T; El Farouki, M R; Benyahia, M

    2016-03-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and neuroimaging entity characterized by headache, visual field deficits, changes in mentation and seizures, and by typical neuro-imaging features such as areas of sub-cortical edema, occasionally cortical, involving predominantly the occipital and parietal lobes of both hemispheres. Hypertension, uremia, immunosuppressive drugs neurotoxicity, preeclampsia or eclampsia, renal disease, and sepsis are the most common etiologies of PRES. Less common, it has been described in the setting of autoimmune disease. We report a case of PRES which was associated with hypertensive crisis in a patient with renal failure. Antihypertensive therapy and hemodialysis resulted in complete recovery.

  4. Reversible posterior encephalopathy syndrome associated with late onset postpartum eclampsia: A case report

    PubMed Central

    Bo, Qi-Yu; Zhao, Xiu-He; Yang, Xue; Wang, Sheng-Jun

    2016-01-01

    Late onset postpartum eclampsia (LPE) is defined by its onset at >48 h after delivery. Reversible posterior encephalopathy syndrome (RPES) associated with LPE is uncommon, with the majority of RPES cases having a late postpartum onset within 4 weeks after childbirth. The present study reported the case of a 15-year old female presenting with convulsions that began 5 weeks after delivery. A magnetic resonance imaging scan of the brain revealed multiple lesions in the cortex, subcortical region and deep white matter of the bilateral cerebellum, and occipital, frontal and parietal lobes. The clinical manifestations and radiological abnormalities were readily resolved subsequent to antihypertension and anticonvulsion treatment. In conclusion, the present rare case indicates that LPE should be considered as a potential diagnosis even at 4 weeks after delivery. Furthermore, clinicians should familiarize with the reversible radioimaging features of RPES, since early recognition and adequate treatment are important to the outcome of patients. PMID:27602098

  5. Reversible posterior encephalopathy syndrome associated with late onset postpartum eclampsia: A case report

    PubMed Central

    Bo, Qi-Yu; Zhao, Xiu-He; Yang, Xue; Wang, Sheng-Jun

    2016-01-01

    Late onset postpartum eclampsia (LPE) is defined by its onset at >48 h after delivery. Reversible posterior encephalopathy syndrome (RPES) associated with LPE is uncommon, with the majority of RPES cases having a late postpartum onset within 4 weeks after childbirth. The present study reported the case of a 15-year old female presenting with convulsions that began 5 weeks after delivery. A magnetic resonance imaging scan of the brain revealed multiple lesions in the cortex, subcortical region and deep white matter of the bilateral cerebellum, and occipital, frontal and parietal lobes. The clinical manifestations and radiological abnormalities were readily resolved subsequent to antihypertension and anticonvulsion treatment. In conclusion, the present rare case indicates that LPE should be considered as a potential diagnosis even at 4 weeks after delivery. Furthermore, clinicians should familiarize with the reversible radioimaging features of RPES, since early recognition and adequate treatment are important to the outcome of patients.

  6. [Posterior reversible encephalopathy in a case of late-onset eclampsia].

    PubMed

    Castrillo-Sanz, Ana; Mendoza, Amelia; Gutiérrez-Ríos, Raúl; Zamora, M Isabel; Morollón, Noemí; Rodríguez-Sanz, M Fernanda; Duarte, Jacinto

    2013-08-01

    Introduccion. El sindrome de encefalopatia posterior reversible (SEPR) es un sindrome clinico-radiologico de presentacion aguda o subaguda que se caracteriza por la presencia de cefalea, vomitos, crisis epilepticas, trastornos visuales y alteracion del nivel de conciencia asociado a lesiones localizadas fundamentalmente en la sustancia blanca de regiones posteriores cerebrales. Caso clinico. Mujer de 32 años que desarrollo un SEPR en el periodo posparto secundario a eclampsia tardia. La paciente presento 10 dias despues del parto un cuadro clinico consistente en cefalea, crisis epilepticas, ceguera y deterioro del nivel de conciencia. El estudio de imagen con resonancia magnetica confirmo la afectacion de la sustancia blanca de predominio posterior. Conclusiones. Aunque la eclampsia es una entidad tipica del embarazo y puerperio inmediato, es necesario recordar que tambien puede producirse de forma tardia tras el parto y que puede ser la causa de otros sindromes, como el SEPR. Aunque en estos casos el pronostico suele ser favorable, el tratamiento debe ser precoz, efectuando un rapido control de la tension arterial y las convulsiones con el fin de evitar un daño cerebral permanente. Es necesario considerar siempre este sindrome en mujeres con crisis epilepticas u otros sintomas neurologicos durante el posparto.

  7. [A case of posterior reversible encephalopathy syndrome associated with Takayasu's arteritis].

    PubMed

    Wakida, Kenji; Morita, Hiroyuki; Sakurai, Takeo; Nishida, Hiroshi

    2016-01-01

    A 75-year-old woman presented with a 4-month history of repetitive loss of consciousness, dizziness, and ear fullness. Fluid attenuation inversion recovery magnetic resonance imaging showed high-intensity areas in the right occipital lobe, both frontal lobes, and parietal lobes, and the patient was therefore admitted to our department for further examination. Neurologic findings included a positive Barré sign (right upper extremity), impaired tandem gait, and positive left-sided Babinski reflex. The patient was diagnosed with Takayasu's arteritis owing to a difference in blood pressure between the left and right upper extremity, weakened pulse in the left upper extremity, as well as thickened arterial wall, and delayed enhancement on a contrast-enhanced computed tomography image. The head magnetic resonance imaging findings disappeared within 4 months and the patient was diagnosed with posterior reversible encephalopathy syndrome. Posterior reversible encephalopathy syndrome associated with elderly female Takayasu's arteritis is rare. ; the present case therefore offers valuable information. PMID:26912227

  8. Posterior reversible encephalopathy syndrome following hemodynamic treatment of aneurysmal subarachnoid hemorrhage-induced vasospasm.

    PubMed

    Awori, Jonathan; Rajajee, Venkatakrishna; Gemmete, Joseph J; Chaudhary, Neeraj; Thompson, B Gregory; Pandey, Aditya S

    2016-04-01

    Posterior reversible encephalopathy syndrome (PRES) is an uncommon but significant complication of hemodynamic therapy after aneurysmal subarachnoid hemorrhage (aSAH)-induced vasospasm. We performed a PubMed literature search for the period January 1999 to January 2015 using the search terms "posterior reversible encephalopathy syndrome", "subarachnoid hemorrhage", "vasospasm", and "hypertensive encephalopathy", and identified nine cases of PRES after aSAH-induced vasospasm in the literature. We also present a 63-year-old man with aSAH complicated by vasospasm treated with hemodynamic augmentation who subsequently developed PRES. Imaging following development of PRES symptoms shows vasogenic edema in the white matter of the parietal and occipital lobes. Age, sex, history of hypertension, and baseline blood pressure were variable among patients in the literature review. In all cases, patients improved both from a radiological and clinical perspective following blood pressure reduction. To summarize, PRES is a rare complication of hemodynamic therapy for vasospasm following aSAH. The literature at the time of writing demonstrates no common pattern with regard to patient demographics, medical history, or mode of treatment for symptomatic vasospasm. Given its sporadic and unpredictable nature, considering PRES in the differential diagnosis is important when addressing neurological decline following hemodynamic treatment of vasospasm related to aSAH. PMID:26755456

  9. Posterior reversible encephalopathy syndrome masquerading as progressive multifocal leukoencephalopathy in rituximab treated neuromyelitis optica.

    PubMed

    Berger, Joseph R; Neltner, Janna; Smith, Charles; Cambi, Franca

    2014-11-01

    Both progressive multifocal leukoencephalopathy (PML) and posterior reversible encephalopathy syndrome (PRES) have been reported as complications of rituximab therapy. These disorders may appear indistinguishable on magnetic resonance imaging (MRI). We report on a 42 year old woman with neuromyelitis optica (NMO) of 10 years duration who developed extensive white matter disease affecting chiefly both parietal lobes 6 months after her first and only dose of rituximab. The MRI findings suggested the diagnosis of PML, but her history was more consistent with PRES. Ultimately, a brain biopsy was performed which was consistent with the diagnosis of PRES. PRES and PML may have overlapping symptomatology and be indistinguishable on MRI. An approach to distinguishing between these two disorders is addressed.

  10. Subarachnoid hemorrhage due to ruptured intracranial aneurysm following posterior reversible encephalopathy syndrome

    PubMed Central

    Nanba, Takamasa; Kashimura, Hiroshi; Saura, Hiroaki; Takeda, Masaru

    2016-01-01

    Although posterior reversible encephalopathy syndrome (PRES) is rarely associated with subarachnoid hemorrhage, to our knowledge, rupture of a concomitant cerebral aneurysm following PRES has not been reported. We describe a patient with atypical PRES involving the brainstem, thalamus, and periventricular white matter without cortical or subcortical edema of the parietooccipital lobe on magnetic resonance imaging, with rupture of a concomitant cerebral aneurysm. Preexisting extremely high blood pressure may trigger atypical PRES, and failure to lower blood pressure may lead to a concomitant aneurysm rupture. In the future treatment of hypertensive urgency with a recurrence of symptoms and mean arterial blood pressure >150 mmHg, it is advisable to immediately hospitalize the patient for aggressive blood pressure management, especially if PRES is suspected based on clinical and radiological features. PMID:27365964

  11. Iatrogenic Coagulopathy and the Development of Posterior Reversible Encephalopathy Syndrome after L-asparaginase Chemotherapy

    PubMed Central

    Rota, Eugenia; Vallisa, Daniele; Morelli, Nicola; Scagnelli, Paola

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological syndrome mostly related to hypertension, eclampsia, renal failure, or to chemotherapy and/or immunosuppressive drugs. Although the PRES pathophysiology is multifactorial, hypertension and endothelial dysfunction are hypothesized to be the pivotal factors. Here we report a case of PRES in an adult patient after chemotherapy (Escherichia coli L-asparaginase [L-ASP], daunorubicin, vincristine, and intrathecal methotrexate) for acute lymphoblastic leukemia. The development of the PRES was strictly associated with an iatrogenic coagulopathy induced by L-ASP, which inhibits the biosynthesis of hepatic coagulation factors. The nadir of platelet count, antithrombin III (ATIII) and fibrinogen curve was coincident with the onset of the PRES neurological picture; subsequently, the normalization of the ATIII and fibrinogen levels seemed to parallel the good clinical evolution. This case seems to provide new insights into the PRES pathophysiological mechanisms. PMID:27014503

  12. Neuromyelitis Optica in Pregnancy Complicated by Posterior Reversible Encephalopathy Syndrome, Eclampsia and Fetal Death

    PubMed Central

    Igel, Catherine; Garretto, Diana; Robbins, Matthew S; Swerdlow, Michael; Judge, Nancy; Dayal, Ashlesha

    2015-01-01

    Neuromyelitis optica (NMO) is a demyelinating syndrome characterized by optic neuritis and acute myelitis with poor recovery and a progressive course. We report a poor outcome complicated by posterior reversible encephalopathy syndrome (PRES) and eclampsia and review available literature and current evidence for anticipation of adverse fetal and maternal effects. After a pregnancy complicated by multiple admissions for painful NMO exacerbations, a primiparous patient with seropositive NMO presented at 31 + 3/7 weeks with eclampsia, HELLP and subsequent fetal death. MRI confirmed PRES. NMO may be associated with eclampsia and leads to adverse maternal and fetal outcomes. Posited mechanisms include antibody-mediated placental damage and a heightened risk of eclampsia-associated PRES. Further characterization of the course of NMO and its relationship with pregnancy outcomes in larger series would be invaluable. PMID:25584107

  13. Posterior reversible encephalopathy syndrome in malignant hypertension secondary to focal segmental glomerulosclerosis.

    PubMed

    Abdullah, Hafez Mohammad Ammar; Ullah, Waqas; Ahmad, Ejaz; Anwer, Faiz

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological condition that occurs secondary to a variety of causes like autoimmune diseases, uncontrolled hypertension and immunosuppressive agents. We report an unusual association of PRES and malignant hypertension secondary to focal segmental glomerulosclerosis in a young woman, presenting with sudden loss of vision and seizures. She had uncontrolled hypertension and a Glasgow Coma Scale of 6/15. Brain MRI revealed high signals in cortical and subcortical white matter and some involvement of the periventricular areas. She improved dramatically with antihypertensive and antiepileptic medications and was discharged home in a stable condition. It is important to have a high clinical suspicion for this uncommon condition in an appropriate clinical setting, because a timely intervention can prevent long-term complications. PMID:27535734

  14. [Recurrent posterior reversible encephalopathy due to vasospasm and cerebral hypoperfusionin in acute leukemia: a case report].

    PubMed

    Hiraide, Takuya; Matsubayashi, Tomoko; Ishigaki, Hidetoshi; Asahina, Miki; Sakaguchi, Kimiyoshi; Fukuda, Tokiko

    2015-11-01

    We report the case of a 4-year-old girl who presented with recurrent posterior reversible encephalopathy syndrome (PRES). She was diagnosed with B-precursor acute lymphocytic leukemia (ALL), and was administered remission-induction chemotherapy. On day 28 of the induction therapy, she experienced seizure and prolonged unconsciousness. Blood pressure was slightly elevated. MRI revealed cortical cytotoxic edema in the right temporal and occipital lobes. In the right occipital white matter the lesion with vasogenic edema also existed. Three days later, MRI showed vasogenic edema in subcortical white matter of the right temporal right occipital and bilateral occipital lobes. The lesions had receded with time. Since the seizure occurred, the chemotherapy had been discontinued. The episodes of seizure and prolonged consciousness recurred 22 days later. MRI revealed vasogenic edema in the right occipital lobe, and MR angiography demonstrated vessel irregularity and reduced branch visualization in the middle and posterior cerebral arteries. Arterial spin-labeling (ASL) showed hypoperfusion in both occipital lobes. It suggests that vasoconstriction and hypoperfusion could lead to recurrent PRES in this case. It is possible that ASL might be more sensitive than MRI in detecting the lesions of PRES. It should be noted that PRES might recur in leukemia. PMID:26717647

  15. Posterior Reversible Encephalopathy Syndrome in Henoch-Schonlein Purpura and Hemolytic Uremic Syndrome

    PubMed Central

    Fidan, Kibriya; Kandur, Yasar; Ucar, Murat; Gucuyener, Kivilcim; Soylemezoglu, Oguz

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome, composed of symptoms such as headache, seizures, visual disturbances, lethargy, confusion, stupor, focal neurologic findings and radiological findings of bilateral gray and white matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres. PRES is associated with significant morbidity and mortality if it is not expeditiously recognized. Magnetic resonance image (MRI) represents the most sensitive imaging technique for recognizing PRES. PRES has been seen in various clinical settings including renal disorders such as acute glomerulonephritis, lupus nephritis, nephrotic syndrome, and drug usage such as calcineurin inhibitors. We aimed to present two study cases for such clinical setting. In this report, we present two patients with PRES in whom the primary diagnosis was hemolytic uremic syndrome (HUS) and Henoch-Schonlein purpura (HSP). Both of them were treated with anticonvulsant and proper antihypertensive drugs. A repeated MRI scan of the head, an ophthalmologic assessment, and a follow-up electroencephalogram produced normal results with no sequelae. Early recognition of PRES as a complication during different diseases and therapies in childhood may facilitate the appropriate treatment, so that intensive treatment should be performed as soon as possible to avoid neurological sequelae. PMID:27298664

  16. Calcineurin Inhibitors Associated Posterior Reversible Encephalopathy Syndrome in Solid Organ Transplantation

    PubMed Central

    Song, Turun; Rao, Zhengsheng; Tan, Qiling; Qiu, Yang; Liu, Jinpeng; Huang, Zhongli; Wang, Xianding; Lin, Tao

    2016-01-01

    Abstract Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic side effect of calcineurin inhibitors (CNIs) with poorly understood clinical features. We report cases of 2 patients with PRES developing after kidney transplantation and summarize PRES clinical features through a literature review. The 1st case was a 28-year-old man who received a kidney transplant from a deceased donor. Initial immunosuppressive therapy consisted of tacrolimus/mycophenolate mofetil/prednisolone. He developed headache and blurred vision with visual field loss15 days after transplantation and generalized seizures 4 days later. The 2nd case was a 34-year-old man who received a living kidney transplant. His initial immunosuppressive therapy comprised tacrolimus/mycophenolate mofetil/prednisolone. Two months after transplantation, he developed seizures. Both patients were diagnosed with PRES based on neurological symptoms and magnetic resonance imaging (MRI) findings; they recovered after switching from tacrolimus to either a cyclosporine or a lower tacrolimus dose. CNI-associated PRES is an acute neurological syndrome with seizures, encephalopathy, visual abnormalities, headache, focal neurological deficits, and nausea/vomiting. It is always accompanied by hypertension. A fluid-attenuated inversion recovery signal MRI scan typically shows reversible subcortical white matter changes in the posterior cerebral hemisphere that usually occur within the 1st month after transplantation. CNI-associated PRES has a generally favorable prognosis with early diagnosis and prompt treatment including alternating or discontinuing CNIs and blood pressure control. CNI-associated PRES should be considered in patients exhibiting acute neurological symptoms after transplantation. Early diagnosis and immediate treatment are critical for a favorable prognosis. PMID:27057842

  17. Posterior reversible encephalopathy syndrome in setting of postobstructive diuresis and persistent hypocalcemia.

    PubMed

    Gera, Dinesh N; Patil, Sachin B; Parikh, Mitul; Modi, Pranjal R; Kute, Vivek B; Trivedi, Hargovind L

    2012-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiographic entity of heterogenous etiologies, which are grouped together because of similar findings on neuroimaging studies, associated with similar symptom complex of headache, vision loss, altered mentation, and seizures. In this report, we describe a case of PRES in setting of postobstructive diuresis in a 5-year-old male child, whose solitary functioning kidney was obstructed by a 1.6-cm radio-opaque stone, who after percutaneous nephrostomy (PCN) diversion developed persistent hypocalcemia which persisted despite maximum replacement by iv calcium gluconate drip, and the child developed repeated generalized tonic clonic convulsions and became unconscious for 4 days. Computerized tomography (CT) scan of the brain showed typical hypodensities in bilateral occipitoparietal regions suggesting PRES. Ultimately, over a period of 4 days, his hypocalcemia could be corrected and the child was neurologically normal on the 5th day. CT scan of the brain after a month was free of any hypodensities.

  18. Posterior reversible encephalopathy syndrome (PRES) as a complication of Guillain-Barre' syndrome (GBS).

    PubMed

    Nabi, Sumaira; Rajput, Haris Majid; Badshah, Mazhar; Ahmed, Shahzad

    2016-01-01

    A 17-year-old Pakistani female patient presented with acute onset flaccid quadriparesis with nerve conduction studies showing demyelinating polyneuropathy consistent with Guillain-Barre' syndrome. She was treated with 4 plasmapheresis sessions. She developed raised blood pressure, headache, visual loss and generalised seizures on the 13th day of admission. MRI of the brain on contrast showed findings of altered signals low on T1-weighted image, high on T2-weighted image and fluid-attenuated inversion recovery in the white matter of bilateral occipital, parietal and right frontal lobe consistent with posterior reversible encephalopathy syndrome. The patient was administered antiepileptic and antihypertensive drugs to control seizures and blood pressure. She was discharged in a stable state. On follow-up her visual loss had recovered completely and she had regained full motor strength in all four extremities after 6 weeks. Fresh MRI of the brain revealed complete resolution of lesions. Antihypertensive and antiepileptic medication was discontinued. She is independent in all her daily activities. PMID:27489061

  19. Posterior reversible encephalopathy syndrome following paroxysmal nocturnal hemoglobinuria: a case report and literature review.

    PubMed

    Ding, Dongxue; Li, Kai; Li, Guoliang; Long, Xiaoyan

    2015-01-01

    Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disorder characterized by hemolytic anemia, marrow failure, and a high incidence of life-threatening venous thrombosis. It is subject to a considerable variety of complications like intestinal obstruction and visceral embolism. The current study firstly presents a 40-year-old male with a previous diagnosis of PNH who developed posterior reversible encephalopathy syndrome (PRES) during treatment with methylprednisolone. He was referred to our department with headache and two episodes of generalized tonic-clonic seizures. Laboratory examination revealed peripheral blood cytopenias and elevated count of reticulocyte. Brain magnetic resonance imaging (MRI) exhibited abnormal signal in the bilateral parieto-occipital lobes with symmetric distribution which confirmed the diagnosis of PRES. After receive treatment of dexamethasone, anti-hypertensive and neurotropic drugs, the patient made a complete clinical recovery; and the abnormal signals of MRI were almost completely absorbed. This case shows that PRES might be a rare complication of PNH. Furthermore, it points out the necessity of rapid diagnosis and treatment of PRES. PMID:26379993

  20. The clinical and radiological spectrum of posterior reversible encephalopathy syndrome: the retrospective Berlin PRES study.

    PubMed

    Liman, T G; Bohner, G; Heuschmann, P U; Endres, M; Siebert, E

    2012-01-01

    The aim of the study was to characterize the clinical and radiological spectrum of posterior reversible encephalopathy syndrome (PRES) in a large cohort. The radiological report data bases of the authors' university hospitals were searched for patients with PRES. Various imaging features at onset of symptoms and on follow-up as well as clinical and paraclinical data were tabulated in those patients fulfilling the criteria for PRES. Exploratory univariate analyses were performed. A total of 96 patients with PRES were included into the study. Wide differences in lesion location, diffusivity, distribution pattern, edema severity, hemorrhage, underlying diseases, symptoms, mean arterial pressure (MAP) and coagulation status were encountered. Hemorrhage occurred significantly more frequently in patients with altered coagulation state and was significantly associated with higher edema grades and with the presence of cytotoxic edema. There was a significant difference in MAP between toxic associations with higher MAP in infection, eclampsy and autoimmune disorders, while lower MAP was found in chemotherapy and immunsupression. In 82% of patients complete or near complete resolution of edema was noted during follow-up. Higher MAP levels were associated with incomplete edema resolution. In 43% of patients residual lesions were seen with a relatively even distribution between focal gliosis, infarction, posthemorrhagic residua, atrophy and laminar necrosis. PRES in this large hospital-based retrospective study comprises a wide radiological and clinical spectrum. Residual lesions were encountered more frequently than commonly expected. Our results point towards a differential contribution of high blood pressure to the course of PRES in different underlying etiologies.

  1. Posterior Reversible Encephalopathy Syndrome Complicating Traumatic Pancreatitis: A Pediatric Case Report.

    PubMed

    Sigurtà, Anna; Terzi, Valeria; Regna-Gladin, Caroline; Fumagalli, Roberto

    2016-05-01

    We are reporting a case of posterior reversible encephalopathy syndrome (PRES) developed in an unusual clinical scenario without the presence of the most described symptoms. PRES is a neurological and radiological syndrome described in many different clinical conditions. In children it has been mostly reported in association with hematological and renal disorders.Our patient was a 15 years old boy, admitted to our intensive care unit for pancreatitis after blunt abdominal trauma.During the stay in the intensive care unit, he underwent multiple abdominal surgical interventions for pancreatitis complications. He had a difficult management of analgesia and sedation, being often agitated with high arterial pressure, and he developed a bacterial peritonitis. After 29 days his neurological conditions abruptly worsened with neuroimaging findings consistent with PRES. His clinical conditions progressively improved after sedation and arterial pressure control.He was discharged at home with complete resolution of the neurological and imaging signs 2 months later.The pathophysiology of PRES is controversial and involves disordered autoregulation ascribable to hypertension and endothelial dysfunction. In this case both hypertension and endothelial activation, triggered by sepsis and pancreatitis, could represent the culprits of PRES onset. Even if there is no specific treatment for this condition, a diagnosis is mandatory to start antihypertensive and supportive treatment. We are therefore suggesting to consider PRES in the differential diagnosis of a neurological deterioration preceded by hypertension and/or septic state, even without other "typical" clinical features. PMID:27258506

  2. A case of acute post-streptococcal glomerulonephritis that developed posterior reversible encephalopathy syndrome.

    PubMed

    Kasap, Belde; Çarman, Kürşat Bora; Yiş, Uluç

    2014-12-01

    A 10-year male patient presented with swelling in the face, legs and scrotal area which developed 8 days after tonsillitis treatment. Acute post-sterotococcal glomerulonephritis (APSGN) was considered in the patient whose urinalysis revealed hematuria and proteinuria at nephrotic level, whose urea, creatinine, lipid profile and anti-streptolysine O antibody levels were increased, albumin and C3 value were decreased and whose 24-hour urine test revealed proteinuria. Renal biopsy was found to be compatible with APSGN. In the follow-up, severe headache, vomiting and convulsion were observed under antihypertensive and diuretic treatment and when the blood pressure was 130/80 mmHg (the 99(th) percentile for the patient: 129/88 mmHg). During the follow-up, the blood pressure values increased to 160/90 mmHg. The electroencephalogram (EEG) performed was found to be normal and magnetic resonance imaging (MRI) findings were compatible with posterior reversible encephalopathy syndrome (PRES). MRI was found to be normal at the first month following antihypertensive and anticonvulsive treatment. In the first year of the follow-up, the blood pressure, neurological examination and urinalysis findings were found to be normal. This patient was presented to draw attention to the fact that PRES can also present with a blood pressure tending to increase and with blood pressure values which are not so high. PMID:26078688

  3. Posterior Reversible Encephalopathy Syndrome Resolving Within 48 Hours in a Normotensive Patient Who Underwent Thoracic Spine Surgery

    PubMed Central

    Vakharia, Kunal; Siasios, Ioannis; Dimopoulos, Vassilios G.; Pollina, John

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) usually manifests with severe headaches, seizures, and visual disturbances due to uncontrollable hypertension. A patient (age in the early 60s) with a history of renal cell cancer presented with lower-extremity weakness and paresthesias. Magnetic resonance imaging (MRI) of the thoracic spine revealed a T8 vertebral body metastatic lesion with cord compression at that level. The patient underwent preoperative embolization of the tumor followed by posterior resection and placement of percutaneous pedicle screws and rods. Postoperatively, the patient experienced decreased visual acuity bilaterally. Abnormal MRI findings consisted of T2 hyperintense lesions and fluid-attenuated inversion recovery changes in both occipital lobes, consistent with the unique brain imaging pattern associated with PRES. The patient’s blood pressure was normal and stable from the first day of hospitalization. The patient was kept on high-dose steroid therapy, which was started intraoperatively, and improved within 48 hours after symptom onset. PMID:26858804

  4. Comparison of the Posterior Capsule Rupture Rates Associated with Conventional (Start to Finish) Versus Reverse Methods of Teaching Phacoemulsification

    PubMed Central

    Suryawanshi, Milind; Gogate, Parikshit; Kulkarni, Anil N.; Biradar, Archana; Bhomaj, Pooja

    2016-01-01

    Purpose: Comparison of the rates of posterior capsule rupture (PCR) associated with conventional versus a reverse method of teaching phacoemulsification. Methods: Trainees were taught conventional (start-to-finish) phacoemulsification beginning with an incision (tunnel construction) to capsulorhexis, sculpting, nucleus cracking, segment removal, cortex aspiration, intraocular lens implantation, and viscoelastic removal. In the reverse method, after incision and capsulorhexis, the trainees were progressively taught viscoelastic wash, cortex aspiration, segment removal, nucleus cracking, sculpting, and intraocular lens implantation. Trainees from a Tertiary Eye Care Centre were classified as beginners, for their first 30 cases and then trainees for their next 70 surgeries. Data were collected on posterior capsular rent and vitreous loss during each step of training. Results: Thirty-two ophthalmic surgeons learning phacoemulsification surgery on 609 cataracts cases were supervised by 3 trainers. Fifteen beginners performed 287 surgeries using the conventional method, and 17 beginners performed 322 surgeries with the reverse method. The incidence of PCR was 18/287 (6.2%) with the conventional method and 15/322 (4.6%) with the reverse method (P = 0.38). PCR occurred during cortex aspiration (8/287, 2.8%) and segment removal (5/287, 1.7%) in the conventional method. PCR occurred during nucleus cracking, segment removal, and cortex aspiration (4/322 surgeries for each step, 1.2%). In the follow, 70 cases (trainees) there was no difference in PCR with either method (4.7% vs. 4.3%, P = 0.705). Conclusion: Conventional and reverse method for training phacoemulsification were both safe in a supervised setting. PMID:27162446

  5. Posterior Reversible Encephalopathy Syndrome and Fatal Cryptococcal Meningitis After Immunosuppression in a Patient With Elderly Onset Inflammatory Bowel Disease

    PubMed Central

    Vasant, Dipesh H.; Limdi, Jimmy K.; Borg-Bartolo, Simon P.; Bonington, Alec

    2016-01-01

    Advanced age and associated comorbidities are-recognized predictors of life-threatening adverse outcomes, such as opportunistic infection following immunosuppressive therapy. We describe the case of an elderly patient with stricturing colonic Crohn’s disease and significant clinical comorbidities, initially controlled with corticosteroid induction followed by infliximab, whose course was complicated by fatal disseminated cryptococcal infection and posterior reversible encephalopathy syndrome. Our patient’s case highlights rare, but serious, complications of immunosuppression. In applying modern treatment paradigms to the elderly, the clinician must consider the potential for more pronounced adverse effects in this potentially vulnerable group, maximizing benefit and minimizing harm. PMID:27807560

  6. [Posterior reversible encephalopathy syndrome and cerebrovascular constriction syndrome in the differential diagnosis of post-partum headaches].

    PubMed

    Ruiz López, N; Cano Hernández, B; Balbás Álvarez, S

    2016-02-01

    Postpartum headache can be due to many causes. In a patient with previous epidural analgesia, the headache can be attributed to post-dural puncture headache, even if the symptoms are not typical of this clinical entity. We report a case of a post-partum with accidental dural tap during the insertion of an epidural catheter for labour analgesia, and who referred to headaches in the third post-partum day. Initially, a post-dural puncture headache was suspected, but the subsequent onset of seizures and visual impairment meant that the diagnosis had to be reconsidered. In this case report, the clinical and pathophysiological features of posterior reversible encephalopathy syndrome and reversible cerebral vasoconstriction syndrome, as well as the differential diagnosis of post-partum headaches are described.

  7. Mental reversal of imagined melodies: a role for the posterior parietal cortex.

    PubMed

    Zatorre, Robert J; Halpern, Andrea R; Bouffard, Marc

    2010-04-01

    Two fMRI experiments explored the neural substrates of a musical imagery task that required manipulation of the imagined sounds: temporal reversal of a melody. Musicians were presented with the first few notes of a familiar tune (Experiment 1) or its title (Experiment 2), followed by a string of notes that was either an exact or an inexact reversal. The task was to judge whether the second string was correct or not by mentally reversing all its notes, thus requiring both maintenance and manipulation of the represented string. Both experiments showed considerable activation of the superior parietal lobe (intraparietal sulcus) during the reversal process. Ventrolateral and dorsolateral frontal cortices were also activated, consistent with the memory load required during the task. We also found weaker evidence for some activation of right auditory cortex in both studies, congruent with results from previous simpler music imagery tasks. We interpret these results in the context of other mental transformation tasks, such as mental rotation in the visual domain, which are known to recruit the intraparietal sulcus region, and we propose that this region subserves general computations that require transformations of a sensory input. Mental imagery tasks may thus have both task or modality-specific components as well as components that supersede any specific codes and instead represent amodal mental manipulation. PMID:19366283

  8. [Posterior reversible encephalopathy syndrome of the midbrain and hypothalamus - a case report of uremic encephalopathy presenting with hypersomnia].

    PubMed

    Shiga, Yuji; Kanaya, Yuhei; Kono, Ryuhei; Takeshima, Shinichi; Shimoe, Yutaka; Kuriyama, Masaru

    2016-01-01

    We report the case of a 73-year-old woman presenting with hypersomnia and loss of appetite. She suffered from diabetic nephropathy without receiving dialysis, in addition to hypertension, which was well controlled without marked fluctuation. There were no objective neurological findings. Her laboratory findings showed renal failure with 3.7 mg/dl of serum creatinine and decreased serum sodium and potassium. Brain magnetic resonance imaging (MRI) showed posterior reversible encephalopathy syndrome (PRES) with vasogenic edema, which was distributed in the dorsal midbrain, medial thalamus, and hypothalamus. After we addressed the electrolyte imbalance and dehydration, her symptoms and MRI findings gradually improved, but faint high signals on MRI were still present 3 months later. Orexin in the cerebrospinal fluid was decreased on admission, but improved 6 months later. We diagnosed uremic encephalopathy with atypical form PRES showing functional disturbance of the hypothalamus. PMID:26640128

  9. Acute intermittent porphyria presenting with posterior reversible encephalopathy syndrome and lateralized periodic discharges plus fast activity on EEG.

    PubMed

    Silveira, Diosely C; Bashir, Mahrukh; Daniel, Joshua; Lucena, Michelle H; Bonpietro, Frank

    2016-01-01

    We report on a 20-year-old patient with a 6-month history of recurrent abdominal pain and a 3-day history of vomiting, hypertension, seizures, and encephalopathy. The brain MRI showed posterior reversible encephalopathy syndrome, and continuous EEG (cEEG) monitoring showed lateralized periodic discharges plus fast activity. Comprehensive CSF studies were negative. Because of severe abdominal pain without a definite etiology, we requested urine porphobilinogen and serum and fecal porphyrins, which suggested acute intermittent porphyria (AIP). The patient had a complete resolution of her symptoms with carbohydrate loading and high caloric diet. Acute intermittent porphyria is potentially life-threatening without proper management and prevention of triggers if it is not recognized.

  10. Acute intermittent porphyria presenting with posterior reversible encephalopathy syndrome and lateralized periodic discharges plus fast activity on EEG.

    PubMed

    Silveira, Diosely C; Bashir, Mahrukh; Daniel, Joshua; Lucena, Michelle H; Bonpietro, Frank

    2016-01-01

    We report on a 20-year-old patient with a 6-month history of recurrent abdominal pain and a 3-day history of vomiting, hypertension, seizures, and encephalopathy. The brain MRI showed posterior reversible encephalopathy syndrome, and continuous EEG (cEEG) monitoring showed lateralized periodic discharges plus fast activity. Comprehensive CSF studies were negative. Because of severe abdominal pain without a definite etiology, we requested urine porphobilinogen and serum and fecal porphyrins, which suggested acute intermittent porphyria (AIP). The patient had a complete resolution of her symptoms with carbohydrate loading and high caloric diet. Acute intermittent porphyria is potentially life-threatening without proper management and prevention of triggers if it is not recognized. PMID:27660746

  11. [Anesthetic Management of a Parturient with Eclampsia, Posterior Reversible Encephalopathy Syndrome and Pulmonary Edema due to Pregnancy-induced Hypertension].

    PubMed

    Aida, Junko; Okutani, Hiroai; Oda, Yutaka; Okutani, Ryu

    2015-08-01

    A 27-year-old woman with mental retardation was admitted to a nearby hospital for an abrupt onset of seizure. Physical examination revealed remarkable hypertension and pregnancy with estimated gestational age of 28th week. Severe pulmonary edema and hypoxia led to a diagnosis of pregnancy-induced hypertension (PIH) accompanied by eclampsia. She was orotracheally intubated because of refractory seizure and hypoxemia, and transferred to our hospital for further treatment. Besides severe hypoxia and hypercapnea, an enhanced lesion was detected in the left posterior cerebrum by brain MRI. No abnormal findings were detected in the fetus, with heart rate of 150 beats x min. She was diagnosed with posterior reversible encephalopathy syndrome (PRES) caused by PIH and emergency cesarean section under general anesthesia was scheduled. A male newborn was delivered with Apgar score of 1/4 (1/5 min), followed by starting continuous infusion of nicardipine for controlling hypertension. Chest X-P on completion of surgery revealed remarkably alleviated pulmonary edema. She received intensive treatment and continued positive pressure ventilation for four days after delivery. She recovered with no neurological deficits and her child was well without any complications. PMID:26442424

  12. Calcineurin Inhibitors Associated Posterior Reversible Encephalopathy Syndrome in Solid Organ Transplantation: Report of 2 Cases and Literature Review.

    PubMed

    Song, Turun; Rao, Zhengsheng; Tan, Qiling; Qiu, Yang; Liu, Jinpeng; Huang, Zhongli; Wang, Xianding; Lin, Tao

    2016-04-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare neurologic side effect of calcineurin inhibitors (CNIs) with poorly understood clinical features.We report cases of 2 patients with PRES developing after kidney transplantation and summarize PRES clinical features through a literature review.The 1st case was a 28-year-old man who received a kidney transplant from a deceased donor. Initial immunosuppressive therapy consisted of tacrolimus/mycophenolate mofetil/prednisolone. He developed headache and blurred vision with visual field loss15 days after transplantation and generalized seizures 4 days later. The 2nd case was a 34-year-old man who received a living kidney transplant. His initial immunosuppressive therapy comprised tacrolimus/mycophenolate mofetil/prednisolone. Two months after transplantation, he developed seizures. Both patients were diagnosed with PRES based on neurological symptoms and magnetic resonance imaging (MRI) findings; they recovered after switching from tacrolimus to either a cyclosporine or a lower tacrolimus dose. CNI-associated PRES is an acute neurological syndrome with seizures, encephalopathy, visual abnormalities, headache, focal neurological deficits, and nausea/vomiting. It is always accompanied by hypertension. A fluid-attenuated inversion recovery signal MRI scan typically shows reversible subcortical white matter changes in the posterior cerebral hemisphere that usually occur within the 1st month after transplantation. CNI-associated PRES has a generally favorable prognosis with early diagnosis and prompt treatment including alternating or discontinuing CNIs and blood pressure control.CNI-associated PRES should be considered in patients exhibiting acute neurological symptoms after transplantation. Early diagnosis and immediate treatment are critical for a favorable prognosis. PMID:27057842

  13. [Unilateral Posterior Reversible Encephalopathy Syndrome after Ventriculo-Peritoneal Shunt for Normal Pressure Hydrocephalus Following Subarachnoid Hemorrhage: A Case Report].

    PubMed

    Sato, Hiroyuki; Koizumi, Takayuki; Sato, Daisuke; Endo, Shin; Kato, Syunichi

    2016-06-01

    The patient, a 79-year-old man, experienced a Hunt & Kosnik grade IV subarachnoid hemorrhage, presenting with sudden-onset coma and severe left hemiplegia. We performed cranial clipping surgery for a ruptured aneurysm on the right middle cerebral artery the same day. Post-operative recovery proceeded smoothly, with gradual improvements in disturbed consciousness and left hemiplegia. Three weeks post-operation, CT revealed low-density areas in the right frontal and temporal lobe, believed to be due to subarachnoid hemorrhage, as well as hydrocephaly. We then performed a lumbo-peritoneal (L-P) shunt for the hydrocephaly. Two months later, the patient experienced shunt occlusion, and we performed a ventriculo-peritoneal (V-P) shunt revision (pressure: 6 cm H(2)O). Headaches, severe decline in cognitive function, and worsened left hemiplegia were observed seven weeks post-shunt revision. Cranial CT revealed widespread low-density areas in right posterior cerebral white matter. We suspected unilateral posterior reversible encephalopathy syndrome (PRES) after performing cranial MRI and cerebral angiography. Increasing the set pressure of the shunt improved the symptoms and radiographic findings. PRES is typically bilateral, and unilateral incidents are rare. This is the first report of unilateral PRES secondary to shunt operation. Its unilaterality appears to have been caused by unilateral brain damage or adhesions to the brain surface from the subarachnoid cerebral hemorrhage. Overdrainage post-shunt can also induce PRES. Diagnosis of PRES is more difficult in unilateral cases;practitioners must keep PRES in mind as a rare complication post-shunt operation. PMID:27270150

  14. Relationships between edema degree and clinical and biochemical parameters in posterior reversible encephalopathy syndrome: a preliminary study.

    PubMed

    Bo, Gao; Hui, Liang; Feng-Li, Liu; Cui, Lv

    2012-09-01

    The objective of the study was to investigate the associations between the degree of edema with the clinical and biochemical parameters such as serum lactate dehydrogenase (LDH), albumin (ALB) in posterior reversible encephalopathy syndrome (PRES) patients. Forty-nine patients with typical clinical symptoms and characteristic MR imaging findings of PRES were included in this study. Lactate dehydrogenase and ALB were analyzed with the immunoluminometric assays. Fluid-attenuated inversion recovery images were used to evaluate the distribution of the extent or severity of vasogenic edema by two observers. Correlation analysis between the scores of brain edema and the blood pressures, clinical conditions and biochemical parameters was performed. No significant difference of brain edema score was found between patients with eclampsia, chronic renal failure and other clinical condition (P > 0.05). Both mean arterial pressures and LDH level were moderately correlated with the scores of brain edema distribution (Spearman's ρ test, r = 0.405 and 0.497, respectively, P < 0.01). Serum ALB level was not correlated with the scores of brain edema distribution (P > 0.05). Larger and more diffuse lesions may be predicted by higher LDH level and blood pressure. The overall severity of the systemic process might be predicted by the degree of edema expression in PRES.

  15. Reversible Deactivation of Motor Cortex Reveals Functional Connectivity with Posterior Parietal Cortex in the Prosimian Galago (Otolemur garnettii)

    PubMed Central

    Cooke, Dylan F.; Stepniewska, Iwona; Miller, Daniel J.; Kaas, Jon H.

    2015-01-01

    We examined the functional macrocircuitry of frontoparietal networks in the neocortex of prosimian primates (Otolemur garnettii) using a microfluidic thermal regulator to reversibly deactivate selected regions of motor cortex (M1). During deactivation of either forelimb or mouth/face movement domains within M1, we used long-train intracortical microstimulation techniques to evoke movements from the rostral division of posterior parietal cortex (PPCr). We found that deactivation of M1 movement domains in most instances abolished movements evoked in PPCr. The most common effect of deactivating M1 was to abolish evoked movements in a homotopic domain in PPCr. For example, deactivating M1 forelimb lift domains resulted in loss of evoked movement in forelimb domains in PPCr. However, at some sites, we also observed heterotopic effects; deactivating a specific domain in M1 (e.g., forelimb lift) resulted in loss of evoked movement in a different movement domain in PPCr (e.g., hand-to-mouth or eye-blink). At most sites examined in PPCr, rewarming M1 resulted in a reestablishment of the baseline movement at the same amplitude as that observed before cooling. However, at some sites, reactivation did not result in a return to baseline movement or to the full amplitude of the baseline movement. We discuss our findings in the context of frontoparietal circuits and how they may subserve a repertoire of ecologically relevant behaviors. SIGNIFICANCE STATEMENT The posterior parietal cortex (PPC) of primates integrates sensory information used to guide movements. Different modules within PPC and motor cortex (M1) appear to control various motor behaviors (e.g., reaching, defense, and feeding). How these modules work together may vary across species and may explain differences in dexterity and even the capacity for tool use. We investigated the functional connectivity of these modules in galagos, a prosimian primate with relatively simple frontoparietal circuitry. By deactivating a

  16. Elevation of serum lactate dehydrogenase at posterior reversible encephalopathy syndrome onset in chemotherapy-treated cancer patients.

    PubMed

    Fitzgerald, Ryan T; Wright, Steven M; Samant, Rohan S; Kumar, Manoj; Ramakrishnaiah, Raghu H; Van Hemert, Rudy; Brown, Aliza T; Angtuaco, Edgardo J

    2014-09-01

    The pathophysiology of posterior reversible encephalopathy syndrome (PRES) is incompletely understood; however, an underlying state of immune dysregulation and endothelial dysfunction has been proposed. We examined alterations of serum lactate dehydrogenase (LDH), a marker of endothelial dysfunction, relative to the development of PRES in patients receiving chemotherapy. A retrospective Institutional Review Board approved database of 88 PRES patients was examined. PRES diagnosis was confirmed by congruent clinical diagnosis and MRI. Clinical features at presentation were recorded. Serum LDH values were collected at three time points: prior to, at the time of, and following PRES diagnosis. Student's t-test was employed. LDH values were available during the course of treatment in 12 patients (nine women; mean age 57.8 years [range 33-75 years]). Chemotherapy-associated PRES patients were more likely to be normotensive (25%) versus the non-chemotherapy group (9%). LDH levels at the time of PRES diagnosis were higher than those before and after (p=0.0263), with a mean difference of 114.8 international units/L. Mean time intervals between LDH measurement prior to and following PRES diagnosis were 44.8 days and 51.4 days, respectively. Mean elapsed time between last chemotherapy administration and PRES onset was 11.1days. In conclusion, serum LDH, a marker of endothelial dysfunction, shows statistically significant elevation at the onset of PRES toxicity in cancer patients receiving chemotherapy. Our findings support a systemic process characterized by endothelial injury/dysfunction as a factor, if not the prime event, in the pathophysiology of PRES.

  17. A semi-dominant mutation in the general splicing factor SF3a66 causes anterior-posterior axis reversal in one-cell stage C. elegans embryos.

    PubMed

    Keikhaee, Mohammad R; Nash, Eric B; O'Rourke, Sean M; Bowerman, Bruce

    2014-01-01

    Establishment of anterior-posterior polarity in one-cell stage Caenorhabditis elegans embryos depends in part on astral microtubules. As the zygote enters mitosis, these microtubules promote the establishment of a posterior pole by binding to and protecting a cytoplasmic pool of the posterior polarity protein PAR-2 from phosphorylation by the cortically localized anterior polarity protein PKC-3. Prior to activation of the sperm aster, the oocyte Meiosis I and II spindles assemble and function, usually at the future anterior pole, but these meiotic spindle microtubules fail to establish posterior polarity through PAR-2. Here we show that a semi-dominant mutation in the general splicing factor SF3a66 can lead to a reversed axis of AP polarity that depends on PAR-2 and possibly on close proximity of oocyte meiotic spindles with the cell cortex. One possible explanation is that reduced levels of PKC-3, due to a general splicing defect, can result in axis reversal due to a failure to prevent oocyte meiotic spindle microtubules from interfering with AP axis formation. PMID:25188372

  18. POSTERIOR REVERSIBLE ENCEPHALOPATHY SYNDROME IN NEUROBLASTOMA PATIENTS RECEIVING ANTI-GD2 3F8 MONOCLONAL ANTIBODY

    PubMed Central

    Kushner, Brian H.; Modak, Shakeel; Basu, Ellen M.; Roberts, Stephen S.; Kramer, Kim; Cheung, Nai-Kong V.

    2014-01-01

    Background Posterior reversible encephalopathy syndrome (PRES) comprises clinical and radiologic findings with rapid onset and potentially dire consequences. Patients experience hypertension, seizures, headache, visual disturbance, and/or altered mentation. Magnetic resonance imaging shows edematous changes in brain (especially parietal and occipital lobes). We report PRES associated with anti-GD2 monoclonal antibody (MoAb) immunotherapy which is now standard for high-risk neuroblastoma but has not previously been implicated in PRES. Methods Successive clinical trials using the anti-GD2 MoAb 3F8 for neuroblastoma patients involved multiple cycles of standard-dose 3F8 (SD-3F8) (20 mg/m2/day, x5 days/cycle) or two cycles of high-dose 3F8 (HD-3F8) (80 mg/m2/day, x5 days/cycle) followed by cycles of SD-3F8. Results PRES was diagnosed in 5/215 (2.3%) patients, including 3/160 (1.9%) patients receiving SD-3F8 and 2/55 (3.6%) patients receiving HD-3F8 (p=0.6). All five patients had a rapid return to clinical-radiologic baseline. PRES occurred in 3/26 (11.5%) patients whose prior treatment included external-beam radiotherapy to the brain (2/6 patients status-post total body irradiation plus 1/20 patients status-post craniospinal irradiation) compared to 2/189 (1.1%) patients without prior brain irradiation (p=0.01). Hypertension, which is strongly linked to PRES, reached grade 3 toxicity in 12/215 (5.6%) patients, including the five patients with PRES and seven patients without PRES. Conclusions Patients receiving anti-GD2 MoAb immunotherapy should be closely monitored for, and undergo urgent treatment or evaluation of, symptoms (e.g., hypertension or headaches) that might herald PRES. Prior brain irradiation may be a predisposing factor for PRES with this immunotherapy. PMID:23633099

  19. Differential Impact of Posterior Lesions in the Left and Right Hemisphere on Visual Category Learning and Generalization to Contrast Reversal

    ERIC Educational Resources Information Center

    Langguth, Berthold; Juttner, Martin; Landis, Theodor; Regard, Marianne; Rentschler, Ingo

    2009-01-01

    Hemispheric differences in the learning and generalization of pattern categories were explored in two experiments involving sixteen patients with unilateral posterior, cerebral lesions in the left (LH) or right (RH) hemisphere. In each experiment participants were first trained to criterion in a supervised learning paradigm to categorize a set of…

  20. A global amnesia associated with the specific variant of posterior reversible encephalopathy syndrome (PRES) that developed due to severe preeclampsia and malignant hypertension

    PubMed Central

    Borovac, Josip Anđelo; Božić, Joško; Žaja, Nikola; Kolić, Krešimir; Hrboka, Vedran

    2016-01-01

    A case is reported of a 26-year-old primiparous woman in the 32nd week of gestation who presented to the emergency department with the symptoms of a severe headache, nausea and vomiting. The patient was diagnosed with preeclampsia that later progressed to eclampsia. This state was characterized by a sudden onset of a headache and diplopia that advanced to cortical blindness and precipitated significant alterations in mental status, most notable being global amnesia that resolved within 48 h. A post-partum magnetic resonance imaging of the brain in FLAIR mode revealed multiple cortico-subcortical areas of hyperintense signals suggestive of edematous lesions that chiefly involved occipital and parietal lobes with additional atypical manifestations. Such radiologic findings suggested a posterior reversible encephalopathy syndrome variant with the global amnesia as an extraordinary constituent. This unique feature should be acknowledged when treating a preeclamptic or hypertensive patient that exhibits neurological symptomatology and vision disturbances. PMID:27099774

  1. Release of severe post-burn contracture of the first web space using the reverse posterior interosseous flap: Our experience with 12 cases.

    PubMed

    Kai, Shi; Zhao, Jingchun; Jin, Zhenghua; Wu, Weiwei; Yang, Ming; Wang, Yan; Xie, Chunhui; Yu, Jiaao

    2013-09-01

    We retrospectively assessed outcomes after treating severe contractures of the first web space from burns with the reverse posterior interosseous flaps (RPIF). Twelve consecutive patients (ages 18-58 years) with burns from 10% to 70% (mean, 30.1%) total body surface area and severe contractures of the first web space of the hand (initial thumb to index angles from 10° to 35° [mean, 23°]) underwent contracture release using the RPIF. Seventeen RPIFs were used, with sizes from 9cm×6cm to 14cm×10cm (mean area, 83.6cm(2)). The patients were followed for 5-26 months. All flaps survived completely, rapidly adapted to the recipient beds, and achieved good color and texture harmony. No early complications occurred. Fifteen donor sites were closed with skin grafts. Two donor sites were closed by direct suture. No paralysis of the posterior interosseous nerve was observed in these cases. At last follow-up the mean thumb to index angle was 78°, increasing the web length 260%. All patients regained fundamental hand functions. The RPIF is reliable and safe for releasing severe contractures of the first web space of the hand after burn, with distinct advantages over currently used alternative methods. PMID:23523223

  2. Release of severe post-burn contracture of the first web space using the reverse posterior interosseous flap: Our experience with 12 cases.

    PubMed

    Kai, Shi; Zhao, Jingchun; Jin, Zhenghua; Wu, Weiwei; Yang, Ming; Wang, Yan; Xie, Chunhui; Yu, Jiaao

    2013-09-01

    We retrospectively assessed outcomes after treating severe contractures of the first web space from burns with the reverse posterior interosseous flaps (RPIF). Twelve consecutive patients (ages 18-58 years) with burns from 10% to 70% (mean, 30.1%) total body surface area and severe contractures of the first web space of the hand (initial thumb to index angles from 10° to 35° [mean, 23°]) underwent contracture release using the RPIF. Seventeen RPIFs were used, with sizes from 9cm×6cm to 14cm×10cm (mean area, 83.6cm(2)). The patients were followed for 5-26 months. All flaps survived completely, rapidly adapted to the recipient beds, and achieved good color and texture harmony. No early complications occurred. Fifteen donor sites were closed with skin grafts. Two donor sites were closed by direct suture. No paralysis of the posterior interosseous nerve was observed in these cases. At last follow-up the mean thumb to index angle was 78°, increasing the web length 260%. All patients regained fundamental hand functions. The RPIF is reliable and safe for releasing severe contractures of the first web space of the hand after burn, with distinct advantages over currently used alternative methods.

  3. Long-term consequences of the posterior reversible encephalopathy syndrome in eclampsia and preeclampsia: a review of the obstetric and nonobstetric literature.

    PubMed

    Postma, Ineke R; Slager, Sjoerdtje; Kremer, Hubertus P H; de Groot, Jan Cees; Zeeman, Gerda G

    2014-05-01

    This review summarizes the long-term consequences of the posterior reversible encephalopathy syndrome (PRES) that have been described in the obstetric literature (eclampsia and preeclampsia) and compares these with data from the nonobstetric literature. Preeclampsia is characterized by new-onset hypertension and proteinuria after the 20th week of pregnancy. Neurological symptoms include headache; visual deficits; confusion; seizures; and, in the most severe cases, intracranial hemorrhage. Eclampsia is an acute cerebral complication of preeclampsia, defined as the occurrence of tonic-clonic seizures in pregnant or recently postpartum women. With severe preeclampsia, in conjunction with neurological symptoms, or eclampsia, neuroimaging changes consistent with PRES can be seen. Posterior reversible encephalopathy syndrome is a specific clinicoradiological syndrome presenting with headaches, visual impairment, seizures, and altered mental status. Characteristic neuroimaging features are consistent with cerebral edema predominantly in the parietal and occipital lobes. In addition to preeclampsia/eclampsia, PRES has been associated with various conditions in the nonobstetric population, that is, severe hypertension, transplantation, or autoimmune disease, in combination with immunosuppressive therapy or high-dose chemotherapy for various malignant conditions. Long-term sequelae of both preeclampsia/eclampsia and other PRES-related conditions are poorly described. After eclampsia or preeclampsia, nonspecific white matter lesions may be found on magnetic resonance imaging, which may or may not be related to the PRES episode. Previously (pre)eclamptic women report cognitive failures; however, no neurocognitive impairment has been shown so far. Various nonobstetric PRES-related conditions have been described with long-term neuroimaging abnormalities as well as cognitive problems, epilepsy, or visual impairment. Although no firm conclusions can be drawn because of the

  4. Reversible deactivation of higher-order posterior parietal areas. I. Alterations of receptive field characteristics in early stages of neocortical processing

    PubMed Central

    Cooke, Dylan F.; Goldring, Adam B.; Baldwin, Mary K. L.; Recanzone, Gregg H.; Chen, Arnold; Pan, Tingrui; Simon, Scott I.

    2014-01-01

    Somatosensory processing in the anesthetized macaque monkey was examined by reversibly deactivating posterior parietal areas 5L and 7b and motor/premotor cortex (M1/PM) with microfluidic thermal regulators developed by our laboratories. We examined changes in receptive field size and configuration for neurons in areas 1 and 2 that occurred during and after cooling deactivation. Together the deactivated fields and areas 1 and 2 form part of a network for reaching and grasping in human and nonhuman primates. Cooling area 7b had a dramatic effect on receptive field size for neurons in areas 1 and 2, while cooling area 5 had moderate effects and cooling M1/PM had little effect. Specifically, cooling discrete locations in 7b resulted in expansions of the receptive fields for neurons in areas 1 and 2 that were greater in magnitude and occurred in a higher proportion of sites than similar changes evoked by cooling the other fields. At some sites, the neural receptive field returned to the precooling configuration within 5–22 min of rewarming, but at other sites changes in receptive fields persisted. These results indicate that there are profound top-down influences on sensory processing of early cortical areas in the somatosensory cortex. PMID:25143546

  5. [Development of syndrome of inappropriate secretion of ADH and reversible posterior leukoencephalopathy during initial rituximab-CHOP therapy in a patient with diffuse large B-cell lymphoma].

    PubMed

    Mizutani, Minoru; Nakamori, Yoshiki; Sakaguchi, Haruna; Kageyama, Yuki; Oya, Eiko; Ino, Kazuko; Suzuki, Kei; Sekine, Takao

    2013-03-01

    A 61-year-old woman presented with a right mandibular tumor and was diagnosed with DLBCL clinical stage IIIA from the biopsy results of the tumor and CT examination. An initial rituximab was administrated a week after the first CHOP treatment. During the infusion of rituximab, she exhibited disorientation, seizure, and consciousness disturbance. Hyponatremia due to SIADH and hypertension were coincidentally observed. MRI revealed T2 and FLAIR hyperintense signals involving the bilateral occipital, parietal, frontal lobes and the cerebellum that were consistent with reversible posterior leukoencephalopathy syndrome (RPLS). Her consciousness level recovered in parallel with corrections in serum sodium levels and blood pressure. Although she presented with transient cortical blindness, all neurological abnormalities disappeared 40 hours after the occurrence of seizure. She received a further 7 cycles of CHOP followed by 7 cycles of rituximab treatment with no relapse of RPLS. After irradiation for a residual abdominal tumor, she has maintained complete remission for 2 years. Although RPLS is a rare complication of rituximab-CHOP chemotherapy, it should be considered in patients with DLBCL who present with acute neurological deterioration.

  6. Reversible posterior leukoencephalopathy syndrome following combinatorial cisplatin and pemetrexed therapy for lung cancer in a normotensive patient: A case report and literature review

    PubMed Central

    XIE, CHANGQING; JONES, VOVANTI T.

    2016-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare neurological syndrome of the brain, causing symptoms such as headaches, seizures, altered mental status and visual disturbances. The condition is predominantly associated with hypertension, eclampsia, renal impairment, cytotoxic drugs, immunosuppressive agents and molecular targeted agents, but the precise underlying mechanism of RPLS is not fully understood. The present study describes the case of a 65-year-old female patient with stage IIA non-small cell lung cancer who received cisplatin/pemetrexed treatment at the Leo W. Jenkins Cancer Center. Following 3 cycles of this therapy, the patient was referred to the Emergency Department of Vidant Medical Center with an altered mental status, subsequently presenting with epileptic seizures, a fever and a headache. A neurological examination revealed generalized hyperreflexia and paraparesis, with extensor posturing of the bilateral lower extremities. The lumbar puncture and electroencephalography results were normal, but cranial computed tomography (CT) scans revealed attenuation abnormalities in the bilateral parietal region and the left occipital lobe, with suspected metastasis. Cranial T2-weighted magnetic resonance imaging (MRI) indicated bilateral regions of increased signal intensity in the occipital, temporal and periventricular white matter. The patient was treated with anticonvulsants, steroids and antihypertensive drugs, recovered gradually from the symptoms and regained full consciousness. However, the patient reported residual weakness, presenting with an Eastern Cooperative Oncology Group score of 3, reflective of an inability to independently perform daily activities and self-care. A brain MRI performed 10 days later demonstrated that the subcortical edema had partially subsided. The patient was discharged on day 15 post-admission. A follow-up cranial CT examination 1 month later indicated a partial resolution of the abnormalities. The

  7. Reversals.

    ERIC Educational Resources Information Center

    National Center on Educational Media and Materials for the Handicapped, Columbus, OH.

    Selected from the National Instructional Materials Information System (NIMIS)--a computer based on-line interactive retrieval system on special education materials--the bibliography covers nine materials for remediating reversals in handicapped students at the early childhood and elementary levels. Entries are presented in order of NIMIS accession…

  8. Posterior malleolus fracture.

    PubMed

    Irwin, Todd A; Lien, John; Kadakia, Anish R

    2013-01-01

    Posterior malleolus fractures are a common component of ankle fractures. The morphology is variable; these fractures range from small posterolateral avulsion injuries to large displaced fracture fragments. The integrity of the posterior malleolus and its ligamentous attachment is important for tibiotalar load transfer, posterior talar stability, and rotatory ankle stability. Fixation of posterior malleolus fractures in the setting of rotational ankle injuries has certain benefits, such as restoring articular congruity and rotatory ankle stability, as well as preventing posterior talar translation, but current indications are unclear. Fragment size as a percentage of the anteroposterior dimension of the articular surface is often cited as an indication for fixation, although several factors may contribute to the decision, such as articular impaction, comminution, and syndesmotic stability. Outcome studies show that, in patients with ankle fractures, the presence of a posterior malleolus fracture negatively affects prognosis. Notable variability is evident in surgeon practice. PMID:23281469

  9. Posterior Tibial Tendon Dysfunction

    MedlinePlus

    ... when the posterior tibial tendon becomes inflamed or torn. As a result, the tendon may not be ... repetitive use. Once the tendon becomes inflamed or torn, the arch will slowly fall (collapse) over time. ...

  10. Indirect posterior composite resins.

    PubMed

    Leinfelder, Karl F

    2005-07-01

    The use of indirect posterior composite restorations has facilitated the generation of ideal anatomic form, marginal adaptation, and appropriate proximal contact and contour. Unfortunately, however, the use of post-cure heat treatments has done little to enhance the overall clinical performance of the restoration. The development of new curing techniques in conjunction with modifications of the formulae have contributed to a substantial improvement in both the mechanical characteristics and long-term clinical performance of indirect posterior composite resins.

  11. Posterior leukoencephalopathy syndrome in children and adolescents.

    PubMed

    Alehan, Füsun; Erol, Ilknur; Agildere, A Muhtesem; Ozcay, Figen; Baskin, Esra; Cengiz, Nurcan; Alioglu, Bülent; Haberal, Mehmet

    2007-04-01

    Posterior leukoencephalopathy syndrome is a recently identified clinical and radiologic entity. The characteristic radiologic findings are bilateral gray and white matter edema in the posterior regions of the cerebral hemispheres. This article reports clinical and radiologic findings in 10 consecutive episodes of posterior leukoencephalopathy syndrome that were diagnosed in 9 children and adolescents. The causes were immunosuppressive therapy in 7 patients and a combination of renal failure and hypertension in 3. The most common presenting symptoms were seizure and altered consciousness; others included headache, sixth nerve palsy, and cortical blindness. Imaging demonstrated abnormalities in the parietal and occipital lobes in all 10 episodes. The signs and symptoms resolved after immunosuppressive agents were reduced or discontinued, or after uremia and hypertension were corrected. Four patients underwent follow-up cranial imaging, and the images showed nearly complete or complete resolution. The syndrome was clinically reversible in all patients.

  12. The tibialis posterior tendon.

    PubMed

    Lhoste-Trouilloud, A

    2012-02-01

    The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive "chewing gum" lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.

  13. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  14. Tibialis Posterior Tendon Entrapment Within Posterior Malleolar Fracture Fragment.

    PubMed

    Fantry, Amanda; Lareau, Craig; Vopat, Bryan; Blankenhorn, Brad

    2016-01-01

    Management of posterior malleolus fractures continues to be controversial, with respect to both need for fixation and fixation methods. Fixation methods include an open posterior approach to the ankle as well as percutaneous reduction and fixation with or without arthroscopy for visualization of the articular surface. Plain radiographs are unreliable in identifying fracture pattern and intraoperative reduction, making arthroscopy a valuable adjunct to posterior malleolus fracture management. In this article, we report a case of tibialis posterior tendon entrapment within a posterior malleolus fracture, as identified by arthroscopy and managed with open reduction. Tibialis posterior tendon entrapment within a posterior malleolus has not been previously reported. Ankle arthroscopy for posterior malleolus fractures provides an opportunity to identify soft-tissue or tendinous entrapment, articular surface reduction, and articular cartilage injuries unlikely to be identified with fluoroscopy alone and should be considered in reduction and fixation of posterior malleolus fractures.

  15. Tibialis Posterior Tendon Entrapment Within Posterior Malleolar Fracture Fragment.

    PubMed

    Fantry, Amanda; Lareau, Craig; Vopat, Bryan; Blankenhorn, Brad

    2016-01-01

    Management of posterior malleolus fractures continues to be controversial, with respect to both need for fixation and fixation methods. Fixation methods include an open posterior approach to the ankle as well as percutaneous reduction and fixation with or without arthroscopy for visualization of the articular surface. Plain radiographs are unreliable in identifying fracture pattern and intraoperative reduction, making arthroscopy a valuable adjunct to posterior malleolus fracture management. In this article, we report a case of tibialis posterior tendon entrapment within a posterior malleolus fracture, as identified by arthroscopy and managed with open reduction. Tibialis posterior tendon entrapment within a posterior malleolus has not been previously reported. Ankle arthroscopy for posterior malleolus fractures provides an opportunity to identify soft-tissue or tendinous entrapment, articular surface reduction, and articular cartilage injuries unlikely to be identified with fluoroscopy alone and should be considered in reduction and fixation of posterior malleolus fractures. PMID:26991573

  16. Posterior microphthalmos pigmentary retinopathy syndrome.

    PubMed

    Pehere, Niranjan; Jalali, Subhadra; Deshmukh, Himanshu; Kannabiran, Chitra

    2011-04-01

    Posterior Microphthalmos Pigmentary Retinopathy Syndrome (PMPRS). Posterior microphthalmos (PM) is a relatively infrequent type of microphthalmos where posterior segment is predominantly affected with normal anterior segment measurements. Herein, we report two siblings with posterior microphthalmos retinopathy syndrome with postulated autosomal recessive mode of inheritance. A 13-year-old child had PM and retinitis pigmentosa (RP) and his 7-year-old sister had PM, RP, and foveoschisis. The genetics of this syndrome and variable phenotype is discussed. Importance of being aware of posterior microphthalmos and its posterior segment associations is highlighted.

  17. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  18. Posterior Urethral Strictures.

    PubMed

    Gelman, Joel; Wisenbaugh, Eric S

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  19. Posterior Urethral Strictures

    PubMed Central

    Gelman, Joel; Wisenbaugh, Eric S.

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  20. Posterior Tibial Tendon Transfer.

    PubMed

    Shane, Amber M; Reeves, Christopher L; Cameron, Jordan D; Vazales, Ryan

    2016-01-01

    When performed correctly with the right patient population, a tibialis posterior muscle/tendon transfer is an effective procedure. Many different methods have been established for fixating the tendon, each of which has its' own indications. Passing through the interosseous membrane is the preferred and recommended method and should be used unless this is not possible. Good surgical planning based on patient needs and expectations, along with excellent postoperative care including early range of motion and physical therapy minimizes risk of complications and allows for the optimal outcome to be achieved. PMID:26590722

  1. Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J; Lehmann, Manja; Schott, Jonathan M; Rabinovici, Gil D; Rossor, Martin N; Fox, Nick C

    2013-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that is characterized by a progressive decline in visuospatial, visuoperceptual, literacy and praxic skills. The progressive neurodegeneration affecting parietal, occipital and occipito-temporal cortices which underlies PCA is attributable to Alzheimer's disease (AD) in the majority of patients. However, alternative underlying aetiologies including Dementia with Lewy Bodies (DLB), corticobasal degeneration (CBD) and prion disease have also been identified, and not all PCA patients have atrophy on clinical imaging. This heterogeneity has led to diagnostic and terminological inconsistencies, caused difficulty comparing studies from different centres, and limited the generalizability of clinical trials and investigations of factors driving phenotypic variability. Significant challenges remain in identifying the factors associated with both the selective vulnerability of posterior cortical regions and the young age of onset seen in PCA. Greater awareness of the syndrome and agreement over the correspondence between syndrome-and disease-level classifications are required in order to improve diagnostic accuracy, research study design and clinical management. PMID:22265212

  2. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  3. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  4. Gossypiboma mimicking posterior urethral stricture

    PubMed Central

    Kumar, Bindey; Kumar, Prem; Sinha, Sanjay Kumar; Sinha, Neelam; Hasan, Zaheer; Thakur, Vinit Kumar; Anand, Utpal; Priyadarshi, Rajiv Nayan; Mandal, Manish

    2013-01-01

    INTRODUCTION Foreign bodies in the urogenital tract are not uncommon. Hairpins, glass rods, umbilical tapes, ball point pen are described in lower urogenital tract. Retained gauze piece (gossypiboma) in posterior urethra may cause diagnostic dilemma. Symptoms and investigations may mimic stricture of posterior urethra. PRESENTATION OF CASE Two cases of retained gauze pieces in the urethra are described here. The micturating cystourethrogram was suggestive of posterior urethral stricture. DISCUSSION Two cases described here had retained gauze piece as a cause of filling defect and abnormal appearance in the micturating cystourethrogram. Gossypiboma may be a possibility where posterior urethral stricture are seen after previous surgery in paediatric age group. CONCLUSION In the setting of previous urogenital surgery gossypiboma should be kept in the differential diagnosis where posterior urethral stricture are seen in the paediatric age group. PMID:23500749

  5. Injuries of the posterior cruciate ligament.

    PubMed

    Moyer, R A; Marchetto, P A

    1993-04-01

    A review of the anatomy and biomechanics of the posterior cruciate ligament, and the systematic approach for the diagnosis and treatment of isolated posterior cruciate ligament injuries and posterior cruciate ligament insufficiency in combination with other ligamentous instabilities is discussed.

  6. Comparison of aesthetic posterior restorations.

    PubMed

    Trushkowsky, R D

    1991-09-01

    In the past decade there has been an increased desire by the profession and the public for an aesthetic restoration that will restore a posterior tooth to its original form and function. The currently available aesthetic posterior restoration materials and techniques are porcelain, cast ceramic, direct composite, direct-indirect composite, indirect composite, and CAD-CAM fabrications. The indications and contraindications of these restorative materials and proper diagnosis and case selection are described.

  7. Endothelin: A novel peptide in the posterior pituitary system

    SciTech Connect

    Yoshizawa, Toshihiro; Kanazawa, Ichiro; Shinmi, Osamu; Kimura, Sadao; Yanagisawa, Masashi; Masaki, Tomoh; Uchiyama, Yasuo ); Giaid, A.; Gibson, S.J.; Polak, J.M. )

    1990-01-26

    Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.

  8. Estimation and uncertainty of reversible Markov models.

    PubMed

    Trendelkamp-Schroer, Benjamin; Wu, Hao; Paul, Fabian; Noé, Frank

    2015-11-01

    Reversibility is a key concept in Markov models and master-equation models of molecular kinetics. The analysis and interpretation of the transition matrix encoding the kinetic properties of the model rely heavily on the reversibility property. The estimation of a reversible transition matrix from simulation data is, therefore, crucial to the successful application of the previously developed theory. In this work, we discuss methods for the maximum likelihood estimation of transition matrices from finite simulation data and present a new algorithm for the estimation if reversibility with respect to a given stationary vector is desired. We also develop new methods for the Bayesian posterior inference of reversible transition matrices with and without given stationary vector taking into account the need for a suitable prior distribution preserving the meta-stable features of the observed process during posterior inference. All algorithms here are implemented in the PyEMMA software--http://pyemma.org--as of version 2.0. PMID:26547152

  9. Estimation and uncertainty of reversible Markov models

    NASA Astrophysics Data System (ADS)

    Trendelkamp-Schroer, Benjamin; Wu, Hao; Paul, Fabian; Noé, Frank

    2015-11-01

    Reversibility is a key concept in Markov models and master-equation models of molecular kinetics. The analysis and interpretation of the transition matrix encoding the kinetic properties of the model rely heavily on the reversibility property. The estimation of a reversible transition matrix from simulation data is, therefore, crucial to the successful application of the previously developed theory. In this work, we discuss methods for the maximum likelihood estimation of transition matrices from finite simulation data and present a new algorithm for the estimation if reversibility with respect to a given stationary vector is desired. We also develop new methods for the Bayesian posterior inference of reversible transition matrices with and without given stationary vector taking into account the need for a suitable prior distribution preserving the meta-stable features of the observed process during posterior inference. All algorithms here are implemented in the PyEMMA software — http://pyemma.org — as of version 2.0.

  10. Children's understanding of posterior probability.

    PubMed

    Girotto, Vittorio; Gonzalez, Michel

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five, children's decisions under uncertainty (Study 1) and judgments about random outcomes (Study 2) are correctly affected by posterior information. From the same age, children correctly revise their decisions in situations in which they face a single, uncertain event, produced by an intentional agent (Study 3). The finding that young children have some understanding of posterior probability supports the theory of naive extensional reasoning, and contravenes some pessimistic views of probabilistic reasoning, in particular the evolutionary claim that the human mind cannot deal with single-case probability. PMID:17391661

  11. Rethinking "posterior" tongue-tie.

    PubMed

    Douglas, Pamela Sylvia

    2013-12-01

    Currently, many clinicians who help with breastfeeding problems are diagnosing "posterior" tongue-tie in infants and performing or referring for frenotomy. In this "Speaking Out" article, I argue that the diagnosis of "posterior" tongue-tie has successfully raised awareness of the importance of impaired tongue function in breastfeeding difficulty. However, the diagnosis of "posterior" tongue-tie also applies a reductionist, medicalized theoretical frame to the complex problem of impaired tongue function, risking unintended outcomes. Impaired tongue function arises out of multiple interacting and co-evolving factors, including the interplay between social behaviors concerning breastfeeding and mother-infant biology. Consideration of theoretical frames is vital if we are to build an evidence base through efficient use of the scarce resources available for clinical breastfeeding research and minimize unintended outcomes.

  12. Unsuccessful outcomes after posterior urethroplasty.

    PubMed

    Engel, Oliver; Fisch, Margit

    2015-03-01

    Posterior urethroplasty is the most common strategy for the treatment of post-traumatic urethral injuries. Especially in younger patients, post-traumatic injuries are a common reason for urethral strictures caused by road traffic accidents, with pelvic fracture or direct trauma to the perineum. In many cases early endoscopic realignment is the first attempt to restore the junction between proximal and distal urethra, but in some cases primary realignment is not possible or not enough to treat the urethral injury. In these cases suprapubic cystostomy alone and delayed repair by stricture excision and posterior urethroplasty is an alternative procedure to minimise the risk of stricture recurrence.

  13. Stereolithography for Posterior Fossa Cranioplasty

    PubMed Central

    Agner, Celso; Dujovny, Manuel; Evenhouse, Raymond; Charbel, Fady T.; Sadler, Lewis

    1998-01-01

    Posterior fossa cranioplasty has been suggested for improvement of neurological symptoms following craniectomy. However, there is no particular recommendation in the literature about techniques for prosthesis manufacture and implantation. We report our experience using rapid prototyping technology and stereolithography for pre-surgical implant design and production of cranioplasties. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17171056

  14. Neonatal posterior fossa subdural hematoma.

    PubMed

    Coker, S; Beltran, R; Fine, M

    1987-07-01

    Hemorrhage into the posterior fossa is a rare neurosurgical emergency in neonates. CT scanning is diagnostic. Blood layering under the apex of the tentorium cerebelli, however, may resemble a dilated vascular structure, and the rigidity of the pressured tentorium may prevent upward transmission of increased intracranial pressure, resulting in a soft fontanelle.

  15. A New Variant of Posterior Canal Benign Paroxysmal Positional Vertigo: A Nonampullary or Common Crus Canalolithiasis

    PubMed Central

    Yetiser, Sertac

    2015-01-01

    Clockwise or counterclockwise, rotational, upbeating nystagmus is seen in patients with posterior canal benign paroxysmal positional vertigo during left or right head-hanging test, respectively. Rotating of nystagmus in opposite direction to the ear tested or even reversal of initial positioning rotational nystagmus is not usual and has never been reported before. We propose a new variant of posterior canal benign paroxysmal positional vertigo due to unusual behavior and location of the otoliths inside the membranous labyrinth. Unexpected rotational direction may lead to confusion about the site. The examiner should be aware of this abnormal or atypical variant of posterior canal benign paroxysmal positional vertigo. PMID:26114003

  16. Creep of posterior dental composites.

    PubMed

    Papadogianis, Y; Boyer, D B; Lakes, R S

    1985-01-01

    The creep of microspecimens of posterior dental composites was studied using a torsional creep apparatus. Shear stresses were maintained for 3 h and recovery was followed for 50 h. Creep curves were obtained at 21, 37, and 50 degrees C and four torque levels. The effect of conditioning the specimens in water up to 8 weeks was studied. The posterior composites exhibited linear viscoelastic behavior at low deformations. They had higher shear moduli and greater resistance to creep than conventional and microfilled composites. In aging experiments, maximum shear moduli occurred when specimens were 48 h to 1 week old. Subsequent softening was attributed to water absorption. Residual strain was highest when the composites were stressed within 24 h of initiating polymerization. Residual strain was very low in specimens 48 h to 8 weeks of age.

  17. Posterior cruciate ligament of the knee (image)

    MedlinePlus

    The posterior cruciate ligament (PCL) is a powerful ligament extending from the top-rear surface of the tibia to the bottom-front surface of the femur. The ligament prevents the knee joint from posterior instability.

  18. Osteosarcoma of the posterior maxilla

    PubMed Central

    Prabhusankar, K.; Karande, Amol; Jerry, Jeethu J.; Rishal, Yousef

    2016-01-01

    Osteosarcoma is a very uncommon tumor of the maxillofacial region. Due to the occurrence of the tumor at a young age and its aggressive nature, radical surgery forms the only modality of treatment. A combination of radiotherapy and postoperative chemotherapy has been used for the management of this tumor. A case report of osteosarcoma of the posterior maxilla in an adolescent with a 1-year disease-free follow-up is presented in this report. PMID:27652252

  19. Osteosarcoma of the posterior maxilla.

    PubMed

    Prabhusankar, K; Karande, Amol; Jerry, Jeethu J; Rishal, Yousef

    2016-08-01

    Osteosarcoma is a very uncommon tumor of the maxillofacial region. Due to the occurrence of the tumor at a young age and its aggressive nature, radical surgery forms the only modality of treatment. A combination of radiotherapy and postoperative chemotherapy has been used for the management of this tumor. A case report of osteosarcoma of the posterior maxilla in an adolescent with a 1-year disease-free follow-up is presented in this report. PMID:27652252

  20. Osteosarcoma of the posterior maxilla

    PubMed Central

    Prabhusankar, K.; Karande, Amol; Jerry, Jeethu J.; Rishal, Yousef

    2016-01-01

    Osteosarcoma is a very uncommon tumor of the maxillofacial region. Due to the occurrence of the tumor at a young age and its aggressive nature, radical surgery forms the only modality of treatment. A combination of radiotherapy and postoperative chemotherapy has been used for the management of this tumor. A case report of osteosarcoma of the posterior maxilla in an adolescent with a 1-year disease-free follow-up is presented in this report.

  1. Reversible dementias

    PubMed Central

    Tripathi, Manjari; Vibha, Deepti

    2009-01-01

    In recent years, more attention has been given to the early diagnostic evaluation of patients with dementia which is essential to identify patients with cognitive symptoms who may have treatable conditions. Guidelines suggest that all patients presenting with dementia or cognitive symptoms should be evaluated with a range of laboratory tests, and with structural brain imaging with computed tomography (CT) or magnetic resonance imaging (MRI). While many of the disorders reported as ‘reversible dementias’ are conditions that may well be associated with cognitive or behavioral symptoms, these symptoms are not always sufficiently severe to fulfill the clinical criteria for dementia. Thus, while the etiology of a condition may be treatable it should not be assumed that the associated dementia is fully reversible. Potentially reversible dementias should be identified and treatment considered, even if the symptoms are not sufficiently severe to meet the clinical criteria for dementia, and even if partial or full reversal of the cognitive symptoms cannot be guaranteed. In the literature, the most frequently observed potentially reversible conditions identified in patients with cognitive impairment or dementia are depression, adverse effects of drugs, drug or alcohol abuse, space-occupying lesions, normal pressure hydrocephalus, and metabolic conditions land endocrinal conditions like hypothyroidism and nutritional conditions like vitamin B-12 deficiency. Depression is by far the most common of the potentially reversible conditions. The review, hence addresses the common causes of reversible dementia and the studies published so far. PMID:21416018

  2. Evaluation of arthroscopic treatment of posterior shoulder instability

    PubMed Central

    Garcia, José Carlos; Maia, Lucas Russo; Fonseca, Juliano Rocha; Zabeu, José Luís Amim; Garcia, Jesely Pereira Myrrha

    2015-01-01

    OBJECTIVE: To provide data for the analysis of arthroscopy as a method of surgical treatment for shoulder and discuss its actual indications and preliminary results. METHODS: We evaluated 15 patients submitted to reverse Bankart arthroscopic surgery. We used the UCLA (University of California at Los Angeles) score to measure the results before surgery and 12 months thereafter. RESULTS: The average UCLA score changed from 26.67±0.25 (SD 0.97) before surgery to 34.20±0.53 (SD 2.04) after surgery. The effectiveness of surgery was 93%. In five cases loose bodies were found. A patient undergoing remplissage was evaluated separately. The data did not change after 24 months post-surgery. CONCLUSION: The arthroscopic treatment of posterior shoulder instability and posterior dislocation of the shoulder has been proved feasible and results in our series followed the same trends as in the literature. Level of Evidence III, Transversal Retrospective Study. PMID:26207089

  3. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  4. Reversible Cardiomyopathies

    PubMed Central

    Patel, Harsh; Madanieh, Raef; Kosmas, Constantine E; Vatti, Satya K; Vittorio, Timothy J

    2015-01-01

    Cardiomyopathies (CMs) have many etiological factors that can result in severe structural and functional dysregulation. Fortunately, there are several potentially reversible CMs that are known to improve when the root etiological factor is addressed. In this article, we discuss several of these reversible CMs, including tachycardia-induced, peripartum, inflammatory, hyperthyroidism, Takotsubo, and chronic illness–induced CMs. Our discussion also includes a review on their respective pathophysiology, as well as possible management solutions. PMID:26052233

  5. Posterior fossa syndrome after cerebellar stroke.

    PubMed

    Mariën, Peter; Verslegers, Lieven; Moens, Maarten; Dua, Guido; Herregods, Piet; Verhoeven, Jo

    2013-10-01

    Posterior fossa syndrome (PFS) due to vascular etiology is rare in children and adults. To the best of our knowledge, PFS due to cerebellar stroke has only been reported in patients who also underwent surgical treatment of the underlying vascular cause. We report longitudinal clinical, neurocognitive and neuroradiological findings in a 71-year-old right-handed patient who developed PFS following a right cerebellar haemorrhage that was not surgically evacuated. During follow-up, functional neuroimaging was conducted by means of quantified Tc-99m-ECD SPECT studies. After a 10-day period of akinetic mutism, the clinical picture developed into cerebellar cognitive affective syndrome (CCAS) with reversion to a previously learnt accent, consistent with neurogenic foreign accent syndrome (FAS). No psychometric evidence for dementia was found. Quantified Tc-99m-ECD SPECT studies consistently disclosed perfusional deficits in the anatomoclinically suspected but structurally intact bilateral prefrontal brain regions. Since no surgical treatment of the cerebellar haematoma was performed, this case report is presumably the first description of pure, "non-surgical vascular PFS". In addition, reversion to a previously learnt accent which represents a subtype of FAS has never been reported after cerebellar damage. The combination of this unique constellation of poststroke neurobehavioural changes reflected on SPECT shows that the cerebellum is crucially implicated in the modulation of neurocognitive and affective processes. A decrease of excitatory impulses from the lesioned cerebellum to the structurally intact supratentorial network subserving cognitive, behavioural and affective processes constitutes the likely pathophysiological mechanism underlying PFS and CCAS in this patient. PMID:23575947

  6. Combined Posterior and Anterior Ankle Arthroscopy

    PubMed Central

    Scholten, Peter E.; van Dijk, C. Niek

    2012-01-01

    Treatment of combined anterior and posterior ankle pathology usually consists of either combined anterior and posterior arthrotomies or anterior ankle arthroscopy with an additional posterolateral portal. The first technique bears the risk of complications associated with the extensive exposure, the latter technique provides limited access to the posterior ankle joint. A case is described of combined anterior and posterior arthroscopy, with the patient lying prone and then turned supine, addressing both anterior and posterior ankle pathologies in one tempo. This minimally invasive combined approach allows quick recovery and early return to work and sports activities. PMID:23227391

  7. Posterior leukoencephalopathy syndrome: Postpartum focal neurologic deficits: A report of three cases and review of the literature

    PubMed Central

    Maggi, Genaro; Lombana, Víctor Anillo; Marcos, Estibaliz Alsina; Ruiz Huerta, Ana Domínguez; Arévalo, Emilia Guasch; Rodríguez, Fernando Gilsanz

    2013-01-01

    Posterior reversible encephalopathy syndrome presents with a variety of neurologic features, which, although devastating at some point, are potentially reversible on prompt recognition and institution of appropriated treatment. We report the management of three cases occurring in the last 4 years in our tertiary university hospital. PMID:23956727

  8. New method of posterior scallop augmentation for ischemic mitral regurgitation.

    PubMed

    Aoki, Masakazu; Ito, Toshiaki

    2015-03-01

    We report a new method of posterior middle scallop (P2) augmentation for ischemic mitral regurgitation to achieve deep coaptation. First, P2 was divided straight at the center and partially detached from the annulus in a reverse T shape. A narrow pentagon-shaped section of pericardium was sutured to the divided P2 and annular defect. The tip of the pentagon was attached directly to the papillary muscle, thus creating a very large P2 scallop. A standard-sized ring was placed. We adopted this technique in 2 patients with advanced ischemic cardiomyopathy, and no mitral regurgitation was observed during a 1-year follow-up. PMID:25742844

  9. Longevity of Posterior Composite Restorations

    PubMed Central

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

  10. Huge interparietal posterior fontanel meningohydroencephalocele

    PubMed Central

    Dos Santos, Manuel Filipe Dias; de Santa Barbara, Rita de Cassia

    2015-01-01

    Congenital encephalocele is a neural tube defect characterized by a sac-like protrusion of the brain, meninges, and other intracranial structures through the skull, which is caused by an embryonic development abnormality. The most common location is at the occipital bone, and its incidence varies according to different world regions. We report a case of an 1-month and 7-day-old male child with a huge interparietal-posterior fontanel meningohydroencephalocele, a rare occurrence. Physical examination and volumetric computed tomography were diagnostic. The encephalocele was surgically resected. Intradural and extradural approaches were performed; the bone defect was not primarily closed. Two days after surgery, the patient developed hydrocephaly requiring ventriculoperitoneal shunting. The surgical treatment of the meningohydroencephalocele of the interparietal-posterior fontanel may be accompanied by technical challenges and followed by complications due to the presence of large blood vessels under the overlying skin. In these cases, huge sacs herniate through large bone defects including meninges, brain, and blood vessels. The latter present communication with the superior sagittal sinus and ventricular system. A favorable surgical outcome generally follows an accurate strategy taking into account individual features of the lesion. PMID:26484324

  11. Posterior cerebral artery territory infarctions.

    PubMed

    Cereda, Carlo; Carrera, Emmanuel

    2012-01-01

    Infarctions in the territory of the posterior cerebral artery (PCA) occur in about 5-10% of all ischemic strokes. The PCA can be divided into 'deep' (P1 and P2 segments) and 'superficial' (P3 and P4) segments. Occlusion of paramedian perforating arteries arising from P1 causes rostral midbrain infarction with or without thalamic lesion. The classical clinical triad after thalamomesencephalic infarcts is hypersomnolence, cognitive deficits and vertical oculomotor paresis. Two main arterial groups arise from P2: infarction in the territory of the thalamogeniculate arteries causes severe contralateral hypesthesia and ataxia, whereas infarction in the territory of the posterior choroidal arteries results in sectoranopia with involvement of the lateral geniculate body. After superficial PCA infarcts, visual field defects and somatosensory deficits are the most frequent signs. Additionally, disorders of reading may be seen after unilateral left infarction and disorientation for place and visual neglect after right lesion. After bilateral PCA infarcts, amnesia, cortical blindness (the patient cannot see but pretend he can) may occur. Acute thrombolysis is as useful after PCA infarctions as after anterior circulation strokes. Mortality after PCA strokes is low, but long-term behavioral and cognitive deficits are underestimated.

  12. Endoscopic management of posterior epistaxis: a review.

    PubMed

    McClurg, S W; Carrau, R

    2014-02-01

    The paradigm for the management of epistaxis, specifically posterior epistaxis, has undergone significant changes in the recent past. Recent prospective and retrospective data has shown that the endonasal surgical management of posterior epistaxis is superior to posterior nasal packing and angiography/embolization with regards to various factors including pain, cost-effectiveness, risk and overall control of bleeding. Endonasal endoscopic surgical techniques for posterior epistaxis include direct cauterization and transnasal endoscopic sphenopalatine/ posterior nasal artery ligation or cauterization with or without control of the anterior ethmoidal artery. Despite the evidence provided by the current literature, a universal treatment protocol has not yet been established. This review article provides an up-to-date assessment of the available literature, and presents a structured paradigm for the management of posterior epistaxis.

  13. Placement technique for direct posterior composite restorations.

    PubMed

    Javaheri, D S

    2001-04-01

    Due to improved materials, instrumentation, and placement techniques, composite resins have overcome the traditional complications associated with wear resistance, microleakage, sensitivity, and tight anatomical contacts. Composite resins have been utilized with increased frequency for direct posterior restorations capable of satisfying the growing aesthetic expectations of contemporary dental patients. When properly placed, posterior composites can provide successful and predictable restorations. This article presents clinical considerations for the aesthetic conservation of posterior restorations with composite resin materials.

  14. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures. PMID:3811050

  15. Vasectomy reversal.

    PubMed

    Belker, A M

    1987-02-01

    A vasovasostomy may be performed on an outpatient basis with local anesthesia, but also may be performed on an outpatient basis with epidural or general anesthesia. Local anesthesia is preferred by most of my patients, the majority of whom choose this technique. With proper preoperative and intraoperative sedation, patients sleep lightly through most of the procedure. Because of the length of time often required for bilateral microsurgical vasoepididymostomy, epidural or general anesthesia and overnight hospitalization are usually necessary. Factors influencing the preoperative choice for vasovasostomy or vasoepididymostomy in patients undergoing vasectomy reversal are considered. The preoperative planned choice of vasovasostomy or vasoepididymostomy for patients having vasectomy reversal described herein does not have the support of all urologists who regularly perform these procedures. My present approach has evolved as the data reported in Tables 1 and 2 have become available, but it may change as new information is evaluated. However, it offers a logical method for planning choices of anesthesia and inpatient or outpatient status for patients undergoing vasectomy reversal procedures.

  16. Pseudoaneurysm of the Posterior Tibial Artery After Posterior Tibial Tendon Transfer.

    PubMed

    Elabdi, Monsef; Roukhsi, Redouane; Tijani, Youssef; Chtata, Hassan; Jaafar, Abdeloihab

    2016-01-01

    Pseudoaneurysm of the posterior tibial artery is an uncommon condition that, left untreated, can lead to hemorrhage, thrombosis, or emboli. We present the case of a 54-year-old male who developed pseudoaneurysm of the posterior tibial artery 4 months after undergoing tibialis posterior tendon transfer for management of peroneal nerve palsy, which had developed as a complication of hip arthroplasty. PMID:26972754

  17. Consistently inconsistent, the posterior vaginal wall.

    PubMed

    Hale, Douglass S; Fenner, Dee

    2016-03-01

    Posterior vaginal wall prolapse is one of the most common prolapses encountered by gynecological surgeons. What appears to be a straightforward condition to diagnose and treat surgically for physicians has proven to be frustratingly unpredictable with regard to symptom relief for patients. Functional disorders such as dyssynergic defecation and constipation are often attributed to posterior vaginal wall prolapse. Little scientific evidence supports this assumption, emphasizing that structure and function are not synonymous when treating posterior vaginal wall prolapse. Rectoceles, enteroceles, sigmoidoceles, peritoneoceles, rectal and intraanal intussusception, rectal prolapse, and descending perineal syndrome are all conditions that have an impact on the posterior vaginal wall. All too often these different anatomic conditions are treated with the same surgical approach, addressing a posterior vaginal wall bulge with a traditional posterior colporrhaphy. Studies that examine the correlation between stage of posterior wall prolapse and patient symptoms have failed to reliably do so. Surgical outcomes measured by prolapse staging appear successful, yet patient expectations are often not met. As increasing attention is being placed on patient satisfaction outcomes concerning surgical treatments, this fact will need to be addressed. Surgeons will have to clearly communicate what can and what cannot be expected with surgical repair of posterior vaginal wall prolapse.

  18. Postoperative rehabilitation of the posterior cruciate ligament.

    PubMed

    Edson, Craig J; Fanelli, Gregory C; Beck, John D

    2010-12-01

    Diagnosis and management of posterior cruciate ligament injuries has evolved, and now the treatment often includes surgical intervention. The purpose of this paper is to define the current approach to postsurgical management after the posterior cruciate ligament reconstruction, review conservative management, and discuss surgical outcomes using a specified program.

  19. Neurolinguistic Aspects of Finnish Posterior Aphasia.

    ERIC Educational Resources Information Center

    Niemi, Jussi; Koivuselka-Sallinen, Paivi

    Examination of the lexical errors (phonological paraphasias and neologisms) of two posterior aphasic patients who are speakers of Finnish, a highly synthetic language, revealed that the lexical difficulties generally typical of posterior aphasics were found in these patients as well. The typical lexical difficulties clustered around open class…

  20. Continence after posterior sagittal anorectoplasty.

    PubMed

    Langemeijer, R A; Molenaar, J C

    1991-05-01

    Posterior sagittal anorectoplasty (PSARP) was introduced in 1982 by Peña and De Vries as a new operation for patients with a high anorectal malformation. The degree of postoperative continence is reported to be high. During the past decade, too, new insights have been gained into the embryology of anorectal malformations. Evaluation of PSARP in relation to current understanding of the development and anatomy of the anorectum and the pelvic floor has led us to conclude that optimal continence cannot be expected. Fifty patients with a high anorectal malformation underwent PSARP between June 1983 and May 1990. Postoperative follow-up consisted of anamnesis (subjective) and electrostimulation, defecography, and anorectal manometry (objective). All patients are alive, and all but one are being evaluated regularly. Subjectively, the majority of patients were more or less incontinent, with soiling of pants at least once a day. On the basis of objective criteria, virtually all patients appeared to be incontinent, and in only one patient was the mechanism of defecation almost unimpaired after PSARP. From this study, we conclude that although PSARP provides a good aesthetic result, patients will never acquire normal continence.

  1. Postoperative posterior spinal wound infections.

    PubMed

    Massie, J B; Heller, J G; Abitbol, J J; McPherson, D; Garfin, S R

    1992-11-01

    The incidence of postoperative spinal infections increases with the complexity of the procedure. Diskectomy is associated with less than a 1% risk of infection; spinal fusion without instrumentation is associated with a 1%-5% risk; and fusion with instrumentation may be associated with a risk of 6% or more. Twenty-two postoperative posterior spinal infections that occurred during a three-year period were reviewed for this report. Staphylococcus aureus was the most frequent organism cultured (more than 50% of the cases). Other recurring organisms were Staphylococcus epidermis, Peptococcus, Enterobacter cloacae, and Bacteroides. Many patients had multiple organisms. Risk factors appeared to include advanced age, prolonged hospital bed rest, obesity, diabetes, immunosuppression, and infection at remote sites. Operative factors included prolonged surgery (greater than five hours), high volume of personnel moving through the operating room, and instrumentation. Postoperative contamination may occur and may be related to prolonged postoperative bed rest, skin maceration (thoracolumbosacral orthoses), and drainage tubes exiting distally from lumbar wounds (toward the rectum). Effective treatment includes early diagnosis, surgical debridement and irrigation, and parenteral antibiotics. Superficial infections were treated successfully with wound closure over outflow tubes, and deep infections with inflow-outflow systems. Maintaining the instrumentation in place was possible in most cases. Parenteral antibiotics were maintained for six weeks in every case. PMID:1395319

  2. Posterior labral injury in contact athletes.

    PubMed

    Mair, S D; Zarzour, R H; Speer, K P

    1998-01-01

    Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

  3. Biomechanic effect of posterior cruciate ligament rupture on lateral meniscus

    PubMed Central

    Lei, Pengfei; Sun, Rongxin; Hu, Yihe; Li, Kanghua; Liao, Zhan

    2015-01-01

    Objective: This study aims to investigate the biomechanical effect of posterior cruciate ligament (PCL) rupture on lateral meniscus. Method: The stresses of anterior horn, caudomedial part and posterior horn of lateral meniscus in cadaveric knees were recorded when the knee joints were loaded 200 to 1000 N at 0, 30, 60 and 90° of flexion. Twelve knees were tested before PCL transection (intact group), and 6 each were then tested after anterolateral bundle (ALB group) and postmedial bundle (PMB group) transection. The same knees were finally tested after complete PCL transection. Result: At 0°of knee flexion, the stresses of the anterior horn, caudomedial part and posterior horn were negative and compressive, and were not significantly different between intact and ALB groups, and between completely transected and PMB groups at 200 and 400 N. The stresses of the anterior horn and caudomedial part were greater in completely transected and PMB groups than in intact and ALB groups. The stresses of the posterior horn were smaller in PMB and completely transected groups than in intact and ALB groups. At 600-1000 N, the stresses were significantly different between the groups. The absolute stresses of the anterior horn and caudomedial part were in order of completely transected > PMB > ALB > intact group, while these of the posterior horn were reversed. At 30° of knee flexion, the stresses of the three parts were not significantly different between intact and PMB groups nor between completely transected and ALB groups at 200 and 400 N. The stresses in the anterior horn and caudomedial part were negative and different between completely transected and ALB groups, and positive and different between intact and PMB groups. The stresses in the posterior horn were positive and different between completely transected and ALB groups, and negative and different between intact and PMB groups. At loads of > 600 N, the stresses in the anterior horn and caudomedial part were

  4. Posterior Thigh Flap Pedicled on the Cutaneous Vessels Arising From the Popliteo-posterior Intermediate Artery: A Report of 5 Cases.

    PubMed

    Sun, Xi-Guang; Gong, Xu; Song, Liang-Song; Cui, Jian-Li; Yu, Xin; Liu, Bin; Lu, Lai-Jin

    2016-08-01

    Surgical repair of soft tissue defects of the knee and leg remains challenging. Using a case study approach, the anatomy of the popliteo-posterior intermediate cutaneous artery was examined, and a reverse island flap method was developed and implemented. After obtaining informed consent, 5 patients (1 woman, 4 men, age range 31 to 57 years) underwent the experimental use of a reverse island flap with a posterior thigh flap pedicled on the cutaneous vessels arising from the popliteo-posterior intermediate artery to repair soft-tissue defects of the knee and leg. The defects were caused by burned skin below the knee (n = 1), progressive skin necrosis in the knee after fracture surgery (n = 2), and skin infections associated with diabetes mellitus (n = 2). Skin defect sizes ranged from 15 cm x 5 cm to 30 cm x 12 cm. These large defects did not heal spontaneously; wound duration ranged from 1 week to 1 year, and all patients had refused defect repair with free flaps. Patients received posterior thigh flaps pedicled on the popliteo-posterior intermediate artery with areas ranging from 17 cm x 6 cm to 25 cm x 12 cm. All patients were treated with antibiotics and local dressings (iodoform and alcohol) changed daily post surgery, and blood supply was monitored by assessing the texture and color of the flap and venous regurgitation (ie, vein drainage disturbance). Four (4) of the five flaps survived completely. In 1 patient, partial survival of the flap, which had a good blood supply despite a venous circulation disorder, occurred: in this case, complete survival was achieved after treatment with a retrograde fascial flap and skin grafting. The appearance and texture of all flaps were satisfactory (ie, patients underwent only 1 operation, healing time was approximately 2 weeks, flap quality was close to normal skin, the donor site closed directly, and the shape and function of the knee and leg recovered well). No donor site abnormality was observed, and no postsurgical

  5. Posterior Hip Pain in an Athletic Population

    PubMed Central

    Frank, Rachel M.; Slabaugh, Mark A.; Grumet, Robert C.; Virkus, Walter W.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Context: Posterior hip pain is a relatively uncommon but increasingly recognized complaint in the orthopaedic community. Patient complaints and presentations are often vague or nonspecific, making diagnosis and subsequent treatment decisions difficult. The purposes of this article are to review the anatomy and pathophysiology related to posterior hip pain in the athletic patient population. Evidence Acquisition: Data were collected through a thorough review of the literature via a MEDLINE search of all relevant articles between 1980 and 2010. Results: Many patients who complain of posterior hip pain actually have pain referred from another part of the body—notably, the lumbar spine or sacroiliac joint. Treatment options for posterior hip pain are typically nonoperative; however, surgery is warranted in some cases. Conclusions: Recent advancements in the understanding of hip anatomy, pathophysiology, and treatment options have enabled physicians to better diagnosis athletic hip injuries and select patients for appropriate treatment. PMID:23015944

  6. Congenital abnormalities of the posterior fossa.

    PubMed

    Bosemani, Thangamadhan; Orman, Gunes; Boltshauser, Eugen; Tekes, Aylin; Huisman, Thierry A G M; Poretti, Andrea

    2015-01-01

    The frequency and importance of the evaluation of the posterior fossa have increased significantly over the past 20 years owing to advances in neuroimaging. Nowadays, conventional and advanced neuroimaging techniques allow detailed evaluation of the complex anatomic structures within the posterior fossa. A wide spectrum of congenital abnormalities has been demonstrated, including malformations (anomalies due to an alteration of the primary developmental program caused by a genetic defect) and disruptions (anomalies due to the breakdown of a structure that had a normal developmental potential). Familiarity with the spectrum of congenital posterior fossa anomalies and their well-defined diagnostic criteria is crucial for optimal therapy, an accurate prognosis, and correct genetic counseling. The authors discuss the spectrum of posterior fossa malformations and disruptions, with emphasis on neuroimaging findings (including diagnostic criteria), neurologic presentation, systemic involvement, prognosis, and risk of recurrence.

  7. Congenital abnormalities of the posterior fossa.

    PubMed

    Bosemani, Thangamadhan; Orman, Gunes; Boltshauser, Eugen; Tekes, Aylin; Huisman, Thierry A G M; Poretti, Andrea

    2015-01-01

    The frequency and importance of the evaluation of the posterior fossa have increased significantly over the past 20 years owing to advances in neuroimaging. Nowadays, conventional and advanced neuroimaging techniques allow detailed evaluation of the complex anatomic structures within the posterior fossa. A wide spectrum of congenital abnormalities has been demonstrated, including malformations (anomalies due to an alteration of the primary developmental program caused by a genetic defect) and disruptions (anomalies due to the breakdown of a structure that had a normal developmental potential). Familiarity with the spectrum of congenital posterior fossa anomalies and their well-defined diagnostic criteria is crucial for optimal therapy, an accurate prognosis, and correct genetic counseling. The authors discuss the spectrum of posterior fossa malformations and disruptions, with emphasis on neuroimaging findings (including diagnostic criteria), neurologic presentation, systemic involvement, prognosis, and risk of recurrence. PMID:25590398

  8. [Pathogenesis of posterior capsule opacification in pseudophakia].

    PubMed

    Łukaszewska-Smyk, Agnieszka; Kałuzny, Józef

    2009-01-01

    The lens epithelial cells of A and E type are involved in pathogenesis of posterior capsule opacification (PCO). They undergo metaplasia into microfibroblasts, then migrate towards posterior capsule where they proliferate and form opacification. These processes are stimulated by cytokines and interleukines. The extracellular matrix which constitutes a scaffold for migration and attachment of epithelial cells plays an important role in PCO formation. Integrines intercede in this process.

  9. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region.

    PubMed

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-11-05

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis.

  10. Vertigo due to posterior circulation stroke.

    PubMed

    Kim, Ji Soo; Lee, Hyung

    2013-07-01

    Stroke in the distribution of the posterior circulation may present as acute onset spontaneous vertigo and imbalance. Although vertigo due to posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms. Approximately 17% of patients with isolated posterior inferior cerebellar artery territory infarction presented with isolated vertigo, nystagmus, and postural unsteadiness. A head impulse test can differentiate acute isolated vertigo associated with cerebellar stroke from more benign disorders involving the inner ear. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the anterior inferior cerebellar artery). In this case, evaluation of isolated audiovestibular loss may prevent the progression of acute vertigo and hearing loss into more widespread areas of infarction in the posterior circulation. In this article, the clinical syndromes and signs of acute vestibular syndrome due to posterior circulation stroke involving the brainstem and cerebellum are summarized.

  11. Posterior urethral polyp with type I posterior urethral valves: a rare association in a neonate.

    PubMed

    Kesan, Krushnakumar V; Gupta, Rahul Kumar; Kothari, Paras; Gupta, Abhaya; Mudkhedkar, Kedar; Kamble, Ravikiran; Dikshit, K Vishesh

    2014-06-01

    Urethral polyp is a rare cause of bladder outlet obstruction, voiding dysfunction, and hematuria in the pediatric age group. Urethral polyps are rarely associated with other congenital urinary tract anomalies. In this study, we report a case of solitary posterior urethral polyp with type I posterior urethral valve in a 7-day-old neonate presented with urinary retention and deranged renal function. The polyp was diagnosed on cystoscopy. Transurethral resection of the polyp with posterior urethral valve fulguration was performed. Pathologic assessment revealed a fibroepithelial lesion, which was consistent with congenital posterior urethral polyp.

  12. The posterior chamber phakic refractive lens (PRL): a review

    PubMed Central

    Pérez-Cambrodí, R J; Piñero, D P; Ferrer-Blasco, T; Cerviño, A; Brautaset, R

    2013-01-01

    Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient's accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option. PMID:23222559

  13. Guanylin peptides regulate electrolyte and fluid transport in the Gulf toadfish (Opsanus beta) posterior intestine.

    PubMed

    Ruhr, Ilan M; Bodinier, Charlotte; Mager, Edward M; Esbaugh, Andrew J; Williams, Cameron; Takei, Yoshio; Grosell, Martin

    2014-11-01

    The physiological effects of guanylin (GN) and uroguanylin (UGN) on fluid and electrolyte transport in the teleost fish intestine have yet to be thoroughly investigated. In the present study, the effects of GN, UGN, and renoguanylin (RGN; a GN and UGN homolog) on short-circuit current (Isc) and the transport of Cl-, Na+, bicarbonate (HCO3-), and fluid in the Gulf toadfish (Opsanus beta) intestine were determined using Ussing chambers, pH-stat titration, and intestinal sac experiments. GN, UGN, and RGN reversed the Isc of the posterior intestine (absorptive-to-secretory), but not of the anterior intestine. RGN decreased baseline HCO3- secretion, but increased Cl- and fluid secretion in the posterior intestine. The secretory response of the posterior intestine coincides with the presence of basolateral NKCC1 and apical cystic fibrosis transmembrane conductance regulator (CFTR), the latter of which is lacking in the anterior intestine and is not permeable to HCO3- in the posterior intestine. However, the response to RGN by the posterior intestine is counterintuitive given the known role of the marine teleost intestine as a salt- and water-absorbing organ. These data demonstrate that marine teleosts possess a tissue-specific secretory response, apparently associated with seawater adaptation, the exact role of which remains to be determined.

  14. Detección y estudio mediante Fluorescencia Inducida por Láser de radicales libres formados por Disociación Multifotónica Infrarroja

    NASA Astrophysics Data System (ADS)

    Santos, M.; Díaz, L.; Torresano, J. A.; Rubio, L.; Samoudi, B.

    Una de las principales aplicaciones actuales de los procesos de disociación multifotónica inducidos por radiación láser infrarroja (DMI) es la producción de radiales libres, con el fin de estudiar sus propiedades cinéticas y espectroscópicas. La disociación de moléculas poliatómicas en el IR con láseres de CO2 tiene lugar desde la superficie de energía molecular mas baja y conduce generalmente a la formación de fragmentos en el estado electrónico fundamental, con diversos grados de excitación vibracional. En el Grupo de Procesos Multifotónicos del Instituto de Estructura de la Materia del C.S.I.C. hemos puesto a punto la técnica de Fluorescencia Inducida por Láser (LIF) para la detección y análisis en tiempo real de los fragmentos producidos en la DMI inducida mediante uno o dos campos láseres de diferentes longitudes de onda. Objetivos de nuestro trabajo han sido el estudio de los canales de disociación mayoritarios y de las especies transitoria producidas, así como de la distribución de energía interna con que éstas son generadas. En particular hemos detectado mediante LIF las especies: C2, CF, CH, SiH2, CF2, CH2, SiHCl, y CF3 a partir de la disociación de, entre otras, las siguientes moléculas: C2H3Br, C3F6, C4H8Si, C2H5ClSi y CH5ClSi. En este trabajo presentamos algunos de los resultados obtenidos mediante el estudio por LIF de estos radicales: estudio temporal de la señal LIF obtenida con determinación de tiempos de vida, espectros de excitación y fluorescencia, temperaturas vibracionales de formación, variación de la intensidad LIF con el tiempo de retraso entre los láseres de disociación y prueba, etc.

  15. Posterior Predictive Bayesian Phylogenetic Model Selection

    PubMed Central

    Lewis, Paul O.; Xie, Wangang; Chen, Ming-Hui; Fan, Yu; Kuo, Lynn

    2014-01-01

    We present two distinctly different posterior predictive approaches to Bayesian phylogenetic model selection and illustrate these methods using examples from green algal protein-coding cpDNA sequences and flowering plant rDNA sequences. The Gelfand–Ghosh (GG) approach allows dissection of an overall measure of model fit into components due to posterior predictive variance (GGp) and goodness-of-fit (GGg), which distinguishes this method from the posterior predictive P-value approach. The conditional predictive ordinate (CPO) method provides a site-specific measure of model fit useful for exploratory analyses and can be combined over sites yielding the log pseudomarginal likelihood (LPML) which is useful as an overall measure of model fit. CPO provides a useful cross-validation approach that is computationally efficient, requiring only a sample from the posterior distribution (no additional simulation is required). Both GG and CPO add new perspectives to Bayesian phylogenetic model selection based on the predictive abilities of models and complement the perspective provided by the marginal likelihood (including Bayes Factor comparisons) based solely on the fit of competing models to observed data. [Bayesian; conditional predictive ordinate; CPO; L-measure; LPML; model selection; phylogenetics; posterior predictive.] PMID:24193892

  16. Detailed ophthalmologic evaluation of posterior microphthalmos.

    PubMed

    Alkin, Zeynep; Ozkaya, Abdullah; Karakucuk, Yalcin; Demirok, Ahmet

    2014-01-01

    We performed various ophthalmic investigations in order to confirm the diagnosis and document the various features of posterior microphthalmos in a 21-year-old male. Ophthalmic examination revealed low vision with high hyperopia, papillomacular folds, midperipheral pigmentary changes and crowded optic discs. The optic discs were small and crowded with increased nerve fiber layer thickness. Fundus fluorescein angiography showed reduced diameter of a capillary free zone. Anterior segment (AS) optical coherence tomography demonstrated near normal anterior chamber depths, but markedly diminished anterior chamber angles. In spite of the increased corneal thickness and steep corneas, lens thickness and endothelial cell counts were normal. Sclerochoroidal thickening and foreshortening of the globes were detected with B-scan ultrasonography. Electroretinographic findings and visual field tests were similar to those in pigmentary retinopathy. Posterior microphthalmos is a complex eye disorder, which affects predominantly the posterior segment but also involves the AS of the eye.

  17. Imaging the posterior mediastinum: a multimodality approach.

    PubMed

    Occhipinti, Mariaelena; Heidinger, Benedikt H; Franquet, Elisa; Eisenberg, Ronald L; Bankier, Alexander A

    2015-01-01

    The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information. PMID:25993732

  18. Preformed posterior stainless steel crowns: an update.

    PubMed

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  19. Arthroscopic Approach to Posterior Ankle Impingement.

    PubMed

    Theodoulou, Michael H; Bohman, Laura

    2016-10-01

    Posterior ankle pain can occur for many reasons. If it is produced by forced plantarflexion of the foot, it is often a result of impingement from an enlarged posterior talar process or an os trigonum. This condition may present in an acute or chronic state. Management is initially nonoperative, but surgical treatments are available. This condition is often seen in athletes, so procedures that limit surgical trauma and allow early return to activity are ideal. An arthroscopic approach for this disorder produces good outcomes with limited complications. Understanding the indications, local anatomy, and surgical technique, allows good, reproducible outcomes.

  20. Large posterior abdominal masses: computed tomographic localization.

    PubMed

    Engel, I A; Auh, Y H; Rubenstein, W A; Whalen, J P; Kazam, E

    1983-10-01

    Large posterior abdominal masses, particularly those in the right upper abdomen, may be difficult to localize correctly into the peritoneal or retroperitoneal compartments. The following signs were found to be reliable CT indicators of retroperitoneal location: obliteration of the perinephric fat outlining the psoas muscle; lateral displacement of the fat outlining the posterior right lobe of the liver; rotation of the intrahepatic portal veins to the left; anterior displacement of the inferior vena cava and renal veins; and anterior displacement of the ascending colon, descending duodenum, or pancreatic head.

  1. Arthroscopic Approach to Posterior Ankle Impingement.

    PubMed

    Theodoulou, Michael H; Bohman, Laura

    2016-10-01

    Posterior ankle pain can occur for many reasons. If it is produced by forced plantarflexion of the foot, it is often a result of impingement from an enlarged posterior talar process or an os trigonum. This condition may present in an acute or chronic state. Management is initially nonoperative, but surgical treatments are available. This condition is often seen in athletes, so procedures that limit surgical trauma and allow early return to activity are ideal. An arthroscopic approach for this disorder produces good outcomes with limited complications. Understanding the indications, local anatomy, and surgical technique, allows good, reproducible outcomes. PMID:27599438

  2. [Posterior longitudinal ligament ossification: case report].

    PubMed

    Tella, Oswaldo Inácio de; Herculano, Marco Antonio; Paiva Neto, Manoel Antonio; Faedo Neto, Atílio; Crosera, João Francisco

    2006-03-01

    Posterior longitudinal ligament ossification of cervical spine is a rare condition among caucasians. A 42 years old japanese patient with progressive walking difficulty was diagnosed with this pathology by CT scan and MRI and treated surgically by an anterior approach with arthrodesis. Pathophysiology, racial prevalence, clinical picture, radiological characteristics and surgical approaches options are revised.

  3. Posterior Probabilities for a Consensus Ordering.

    ERIC Educational Resources Information Center

    Fligner, Michael A.; Verducci, Joseph S.

    1990-01-01

    The concept of consensus ordering is defined, and formulas for exact and approximate posterior probabilities for consensus ordering are developed under the assumption of a generalized Mallows' model with a diffuse conjugate prior. These methods are applied to a data set concerning 98 college students. (SLD)

  4. Posterior predictive Bayesian phylogenetic model selection.

    PubMed

    Lewis, Paul O; Xie, Wangang; Chen, Ming-Hui; Fan, Yu; Kuo, Lynn

    2014-05-01

    We present two distinctly different posterior predictive approaches to Bayesian phylogenetic model selection and illustrate these methods using examples from green algal protein-coding cpDNA sequences and flowering plant rDNA sequences. The Gelfand-Ghosh (GG) approach allows dissection of an overall measure of model fit into components due to posterior predictive variance (GGp) and goodness-of-fit (GGg), which distinguishes this method from the posterior predictive P-value approach. The conditional predictive ordinate (CPO) method provides a site-specific measure of model fit useful for exploratory analyses and can be combined over sites yielding the log pseudomarginal likelihood (LPML) which is useful as an overall measure of model fit. CPO provides a useful cross-validation approach that is computationally efficient, requiring only a sample from the posterior distribution (no additional simulation is required). Both GG and CPO add new perspectives to Bayesian phylogenetic model selection based on the predictive abilities of models and complement the perspective provided by the marginal likelihood (including Bayes Factor comparisons) based solely on the fit of competing models to observed data. PMID:24193892

  5. A Complication of Posterior Malleolar Fracture Fixation.

    PubMed

    Patel, Ankit; Charles, Loren; Ritchie, James

    2016-01-01

    We present a case of tibial nerve impingement by an anteroposterior screw inserted for stabilization of a posterior malleolar fracture. This specific complication has not previously been described in published studies, although numerous reports have described various forms of peripheral nerve entrapment. We discuss the merits of fixation of these fractures using a posterolateral approach.

  6. Posterior instability caused by batter's shoulder.

    PubMed

    Kang, Richard W; Mahony, Gregory T; Harris, Thomas C; Dines, Joshua S

    2013-10-01

    In summary, batter’s shoulder is a rare and only recently recognized entity. This condition is posterior shoulder instability caused by a missed attempt at hitting a pitch, especially with an outside pitch. The lack of counterforce from hitting a ball produces increased forces imparted on the posterior capsulolabral complex of the lead shoulder during batting. If the player fails conservative management, she or he can undergo an arthroscopic posterior labral repair instead of debridement. After treatment, the player can expect to return to play after approximately 6 to 7 months. Initial results from a small, retrospective series demonstrate greater than 90% excellent results. These findings are similar to current literature for arthroscopic treatment of posterior instability, which reports success rates that range from 75% to 91%. Longer-term follow-up will be needed to determine the natural history and prognosis or batter’s shoulder. Based on initial results, the authors predict good to excellent results for most players with batter’s shoulder who undergo proper treatment. Additionally, with the exception of switch hitters, the nonthrowing arm is affected. This can also improve the athlete’s return to play.

  7. Posterior instability caused by batter's shoulder.

    PubMed

    Kang, Richard W; Mahony, Gregory T; Harris, Thomas C; Dines, Joshua S

    2013-10-01

    In summary, batter’s shoulder is a rare and only recently recognized entity. This condition is posterior shoulder instability caused by a missed attempt at hitting a pitch, especially with an outside pitch. The lack of counterforce from hitting a ball produces increased forces imparted on the posterior capsulolabral complex of the lead shoulder during batting. If the player fails conservative management, she or he can undergo an arthroscopic posterior labral repair instead of debridement. After treatment, the player can expect to return to play after approximately 6 to 7 months. Initial results from a small, retrospective series demonstrate greater than 90% excellent results. These findings are similar to current literature for arthroscopic treatment of posterior instability, which reports success rates that range from 75% to 91%. Longer-term follow-up will be needed to determine the natural history and prognosis or batter’s shoulder. Based on initial results, the authors predict good to excellent results for most players with batter’s shoulder who undergo proper treatment. Additionally, with the exception of switch hitters, the nonthrowing arm is affected. This can also improve the athlete’s return to play. PMID:24079435

  8. An Unusual Cause of Posterior Elbow Impingement: Detachment of a Hypertrophied Posterior Fat Pad

    PubMed Central

    Hamada, Daisuke; Matsuura, Tetsuya; Sugiura, Kosuke; Higuchi, Tadahiro; Suzue, Naoto; Goto, Tomohiro; Tsutsui, Takahiko; Wada, Keizo; Fukuta, Shoji; Sairyo, Koichi

    2015-01-01

    We report a case of a 47-year-old woman who developed posterior impingement of the elbow due to detachment of a hypertrophied posterior fat pad. She reported acute left elbow pain after leaning back onto a hard object with her hand and subsequently experienced a “catching” sensation. Comparison with the magnetic resonance images of a normal elbow revealed a hypertrophied posterior fat pad interposed between the olecranon and olecranon fossa in both elbows, with the fat pad in the left elbow located more inferiorly than that in the right elbow. Elbow arthroscopy showed the olecranon fossa covered by the fat pad, a portion of which was detached from the rest of the pad. Debridement of the detached portion was performed until no impingement was evident. Postoperatively, full extension of the elbow did not elicit pain. Clinicians should include this pathology among the differential diagnoses for posterior elbow pain. PMID:26613057

  9. Topographic Organization for Delayed Saccades in Human Posterior Parietal Cortex

    PubMed Central

    Schluppeck, Denis; Glimcher, Paul; Heeger, David J.

    2008-01-01

    Posterior parietal cortex (PPC) is thought to play a critical role in decision making, sensory attention, motor intention, and/or working memory. Research on the PPC in non-human primates has focused on the lateral intraparietal area (LIP) in the intraparietal sulcus (IPS). Neurons in LIP respond after the onset of visual targets, just before saccades to those targets, and during the delay period in between. To study the function of posterior parietal cortex in humans, it will be crucial to have a routine and reliable method for localizing specific parietal areas in individual subjects. Here, we show that human PPC contains at least two topographically organized regions, which are candidates for the human homologue of LIP. We mapped the topographic organization of human PPC for delayed (memory guided) saccades using fMRI. Subjects were instructed to fixate centrally while a peripheral target was briefly presented. After a further 3-s delay, subjects made a saccade to the remembered target location followed by a saccade back to fixation and a 1-s inter-trial interval. Targets appeared at successive locations “around the clock” (same eccentricity, ≈30° angular steps), to produce a traveling wave of activity in areas that are topographically organized. PPC exhibited topographic organization for delayed saccades. We defined two areas in each hemisphere that contained topographic maps of the contralateral visual field. These two areas were immediately rostral to V7 as defined by standard retinotopic mapping. The two areas were separated from each other and from V7 by reversals in visual field orientation. However, we leave open the possibility that these two areas will be further subdivided in future studies. Our results demonstrate that topographic maps tile the cortex continuously from V1 well into PPC. PMID:15817644

  10. The posterior sagittal trans-sphincteric approach.

    PubMed

    Peña, A; Hong, A

    2004-01-01

    The posterior sagittal, transphincteric approach to treat different pelvic problems has been known since last century. Although some surgeons have embraced it and have enthusiastically advocated it s use, it has never become an overly popular technique. The purpose of this study is to evaluate the advantages and disadvantages of the approach, both from an historical perspective and from the authors experience. The international literature on the subject was reviewed since 1877 up to the present date. A retrospective evaluation of the authors experience was conducted, and the results reviewed. Specific attention was paid to the final result obtained in the treatment of the original condition, surgical complications and the effect of the surgical approach on bowel and urinary control. The experiential review included 114 cases. They were divided into two groups. A included 85 patients who underwent a posterior sagittal transphincteric approach that included 49 cases of Hirschsprung s disease (primary 21, secondary 28), 15 presacral masses; 10 rectaltumors; 7 acquired recto-genito-urinary fistulae; and 4 cases of idiopathic rectal prolapse. Group B included 29 patients who underwent a posterior sagittal trans-anorectal approach, in which the anterior wall of the rectum and the sphincter was divided as well.. This group included 12 cases of urogenital sinuses; 8 acquired urethral stricture or atresia after trauma; and 9 posterior urethral masses. Post-operative bowel control was normal all cases except in those patients whose basic condition had resulted in fecal incontinence, or who had sustained an irreversible injury prior tothe operation. Urinary control was normal except in cases with pre-operative incontinence. Complications included recurrence of recto-genitourinary fistulae in 3 cases, recto-cutaneous fistula in 3 Hirschsprung s patients and 2 partial wound dehisences. The posterior sagittal trans-sphincteric approach represents a useful technical alternative

  11. [Posterior iris bowing after accommodation--elucidation of the etiology of pigment dispersion syndrome].

    PubMed

    Ueda, J; Sawaguchi, S; Watanabe, J; Shirakashi, M; Abe, H

    1997-02-01

    Recent advancements in imaging the anterior segment structures using the ultrasound biomicro scope (UBM) have proven the involvement of posterior iris bowing due to reverse pupillary block as the cause of pigment dispersion syndrome. In this report, we examined whether the posterior iris bowing occurs even in normal eyes following accommodation, and whether the degree of iris concavity tends to be greater in myopic eyes than in emmetropic eyes. The subjects were normal eyes with sufficient accommodation power, i.e. 5 myopic eyes with less than-5 diopter reflection, 5 emmetropic eyes within +/- 1 dioptor reflection, respectively. We obtained UBM images of the iris at 4 portions before and after accommodation, and measured the degree of posterior iris bowing. We found that almost all data shift posteriorly after accommodation, and that the iris concavity is more distinct in myopic eyes than in emmetropic eyes both before and after accommodation (before: p = 0.0004, after: p < 0.0001). From these results, we confirmed that iris concavity after accommodation occurs in normal eyes but not enough for iridozonular contact, and that pigment dispersion syndrome results from augmented iris concavity owing to pre-existing factors such as iris flexibility, myopia, and sufficient accommodation power. PMID:9124102

  12. Shining a light on posterior cortical atrophy.

    PubMed

    Crutch, Sebastian J; Schott, Jonathan M; Rabinovici, Gil D; Boeve, Bradley F; Cappa, Stefano F; Dickerson, Bradford C; Dubois, Bruno; Graff-Radford, Neill R; Krolak-Salmon, Pierre; Lehmann, Manja; Mendez, Mario F; Pijnenburg, Yolande; Ryan, Natalie S; Scheltens, Philip; Shakespeare, Tim; Tang-Wai, David F; van der Flier, Wiesje M; Bain, Lisa; Carrillo, Maria C; Fox, Nick C

    2013-07-01

    Posterior cortical atrophy (PCA) is a clinicoradiologic syndrome characterized by progressive decline in visual processing skills, relatively intact memory and language in the early stages, and atrophy of posterior brain regions. Misdiagnosis of PCA is common, owing not only to its relative rarity and unusual and variable presentation, but also because patients frequently first seek the opinion of an ophthalmologist, who may note normal eye examinations by their usual tests but may not appreciate cortical brain dysfunction. Seeking to raise awareness of the disease, stimulate research, and promote collaboration, a multidisciplinary group of PCA research clinicians formed an international working party, which had its first face-to-face meeting on July 13, 2012 in Vancouver, Canada, prior to the Alzheimer's Association International Conference. PMID:23274153

  13. Fractures of posterior teeth in adults.

    PubMed

    Eakle, W S; Maxwell, E H; Braly, B V

    1986-02-01

    Examined in this study were 191 patients with 206 complete or incomplete fractures of posterior teeth. The patients ranged in age from 14 to 76 years, with 66.5% younger than 40 years. The number of fractures occurring in each arch was almost equal. The mandibular first molar was the most frequently fractured posterior tooth. The lingual cusps of mandibular molars fractured more often than did the buccal cusps of mandibular molars by a ratio of 2 to 1. In maxillary molars, buccal and lingual cusps fractured with almost equal frequency, but, in maxillary premolars, the lingual cusps fractured slightly more often than buccal cusps. Data gathered on the widths of the isthmuses of restorations in 109 teeth showed that fewer fractures occurred in teeth with more conservative restorations, with widths of isthmuses a quarter of the inter-cusp distance, and intact marginal ridges. PMID:3456380

  14. A new matrix in esthetic posterior restorations.

    PubMed

    Rovatti, L; Cavalleri, G; Dallari, A

    1998-03-01

    Using composite resins in posterior esthetic restorations has become more acceptable in recent years as a result of improvements in materials. For this reason, innovative products such as Luciwedge and the SuperMat System have gained the attention of many practitioners. SuperMat, an improved translucent matrix, offers a new approach to matrices for use with multimaterial fillings. It makes the procedure easier and offers many other advantages, particularly in composite-compomer restorations.

  15. Posterior triangle pain: the os trigonum.

    PubMed

    Martin, B F

    1989-01-01

    Pain emanating from the region of the posterior triangle may present a difficult diagnostic problem for the practitioner. A case of os trigonum pathology with a logical plan for the diagnostic evaluation and resolution of this problem is presented. The use of bone scan and tomography is shown to be helpful for evaluation and arriving at the appropriate diagnosis. Both conservative and surgical treatments are discussed.

  16. The mechanism of continence after posterior urethroplasty

    PubMed Central

    Bagga, Herman S.; Angermeier, Kenneth W.

    2015-01-01

    The standard of care after a pelvic fracture urethral injury is a repair via a one-stage anastomotic posterior urethroplasty using a step-wise perineal approach. The initial injury, immediate postoperative management, and surgical repair can all affect urinary continence in these patients. Proximal continence mechanisms, particularly the bladder neck, are particularly important in maintaining urinary continence in these patients. Patients with bladder neck dysfunction should be counselled about the greater risk of urinary incontinence. PMID:26019981

  17. Cervical disc hernia operations through posterior laminoforaminotomy

    PubMed Central

    Yolas, Coskun; Ozdemir, Nuriye Guzin; Okay, Hilmi Onder; Kanat, Ayhan; Senol, Mehmet; Atci, Ibrahim Burak; Yilmaz, Hakan; Coban, Mustafa Kemal; Yuksel, Mehmet Onur; Kahraman, Umit

    2016-01-01

    Objective: The most common used technique for posterolateral cervical disc herniations is anterior approach. However, posterior cervical laminotoforaminomy can provide excellent results in appropriately selected patients with foraminal stenosis in either soft disc prolapse or cervical spondylosis. The purpose of this study was to present the clinical outcomes following posterior laminoforaminotomy in patients with radiculopathy. Materials and Methods: We retrospectively evaluated 35 patients diagnosed with posterolateral cervical disc herniation and cervical spondylosis with foraminal stenosis causing radiculopathy operated by the posterior cervical keyhole laminoforaminotomy between the years 2010 and 2015. Results: The file records and the radiographic images of the 35 patients were assessed retrospectively. The mean age was 46.4 years (range: 34-66 years). Of the patients, 19 were males and 16 were females. In all of the patients, the neurologic deficit observed was radiculopathy. The posterolaterally localized disc herniations and the osteophytic structures were on the left side in 18 cases and on the right in 17 cases. In 10 of the patients, the disc level was at C5-6, in 18 at C6-7, in 2 at C3-4, in 2 at C4-5, in 1 at C7-T1, in 1 patient at both C5-6 and C6-7, and in 1 at both C4-5 and C5-6. In 14 of these 35 patients, both osteophytic structures and protruded disc herniation were present. Intervertebral foramen stenosis was present in all of the patients with osteophytes. Postoperatively, in 31 patients the complaints were relieved completely and four patients had complaints of neck pain and paresthesia radiating to the arm (the success of operation was 88.5%). On control examinations, there was no finding of instability or cervical kyphosis. Conclusion: Posterior cervical laminoforaminotomy is an alternative appropriate choice in both cervical soft disc herniations and cervical stenosis. PMID:27217655

  18. Electrocardiographic diagnosis of remote posterior wall myocardial infarction using unipolar posterior lead V9

    SciTech Connect

    Rich, M.W.; Imburgia, M.; King, T.R.; Fischer, K.C.; Kovach, K.L. )

    1989-09-01

    The accuracy of four electrocardiographic criteria for diagnosing remote posterior myocardial infarction was assessed prospectively in 369 patients undergoing exercise treadmill testing with thallium scintigraphy. Criteria included the following: (1) R-wave width greater than or equal to 0.04 s and R-wave greater than or equal to S-wave in V1; (2) R-wave greater than or equal to S-wave in V2; (3) T-wave voltage in V2 minus V6 greater than or equal to 0.38 mV (T-wave index); (4) Q-wave greater than or equal to 0.04 s in left paraspinal lead V9. Twenty-seven patients (7.3 percent) met thallium criteria for posterior myocardial infarction, defined as a persistent perfusion defect in the posterobase of the left ventricle. Sensitivities for the four criteria ranged from 4 to 56 percent, and specificities ranged from 64 to 99 percent. Posterior paraspinal lead V9 provided the best overall predictive accuracy (94 percent), positive predictive value (58 percent), and ability to differentiate patients with and without posterior myocardial infarction of any single criterion (p less than .0001). Combining the T-wave index with lead V9 further enhanced the diagnostic yield: the sensitivity for detecting posterior infarction by at least one of these criteria was 78 percent, and when both criteria were positive, specificity was 98.5 percent. It is concluded that a single, unipolar posterior lead in the V9 position is superior to standard 12-lead electrocardiographic criteria in diagnosing remote posterior myocardial infarction, and that combining V9 with the T-wave index maximizes the diagnostic yield.

  19. Reversible Thermoset Adhesives

    NASA Technical Reports Server (NTRS)

    Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

    2016-01-01

    Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

  20. Posterior Ankle and Hind Foot Arthroscopy

    PubMed Central

    Gökkuş, Kemal; Aydın, Ahmet Turan

    2014-01-01

    Objectives: While anterior ankle arthroscopy is a widely accepted technique, posterior ankle/hind foot arthroscopy is still a relatively new procedure. The arthroscopic visualisation was often initially limited and vulnerabilty of the posteromedial neurovascular structures to injury scared orthopaedic surgeons. The goal of this review is to highlight the indications, and to present the long term follow up results of posterior ankle/hind foot arthroscopy. Methods: The study included 21 ankles in 21 patients (12 male and 9 female ).The mean age was 37.7 , the mean duration of preoperative symptoms 12.8 months . Arthroscopy performed with the patient prone , under general and spinal anesthesia with tourniquet hemostasis . Preoperative intravenous antibiotic prophylaxis is performed (cefazolin 1g) , sand bag placed under ipsilateral anteresuperior iliac spine to correct natural external rotated posture of the ankle and ankle is left hanging of the table so that it can moved freely during surgery. We applied noninvasive distraction method with simple rope which tied and knotted waist of the surgeon . The posterolateral and posteromedial portals which described by Van Dijk was utilized . The arthroscopic visualisation was often initially limited and careful debritement of some adipose tissue of the kager fat pad (Kager's fat pad, also known as the pre-Achilles fat pad) was necessary to create more space to aid visualization .The most valuable point to stay clear from trouble is to understand , know and aware where the flexor hallucis longus tendon exist .So neurovascular structures located beyond this tendon. Principally the process must advance into lateral to medial manner. The mean follow up period was 55 months. The most common preoperative diagnoses were osteochondral lesions of talus (ten ),painful os trigonum syndrome with (five )or without (three) FHL tenosynovitis (total eight ), posterior talofibular ligament thickenning (two ), Haglund’s deformity (one

  1. Single burr hole evacuation for traumatic acute subdural hematoma of the posterior fossa in the emergency room.

    PubMed

    Motohashi, Osamu; Kameyama, Motonobu; Shimosegawa, Yasuko; Fujimori, Kiyoshi; Sugai, Kazuyuki; Onuma, Takehide

    2002-08-01

    A 57-year-old man and a 55-year-old man presented with acute subdural hematoma of the posterior cranial fossa due to trauma. Both were comatose preoperatively. Emergent single burr hole evacuation in the posterior cranial fossa was performed in the emergency room immediately after computed tomography. Neurological symptoms improved dramatically just after initiating the burr hole evacuation in both patients. A 57-year-old man became alert and could walk unassisted 1 month after surgery. The other could walk with assistance 4 months after surgery, although psychic disturbance resulting from cerebral contusion remained. Single burr hole evacuation in the emergency room is a useful treatment for acute subdural hematoma of the posterior cranial fossa because the procedure can be performed easily and rapidly, thus achieving reduction of intracranial pressure. Progressing neurological deterioration, reversibility of brainstem function by mannitol administration and the sign of brainstem compression and noncommunicating hydrocephalus are good indicators for this treatment.

  2. Centrally injected histamine increases posterior hypothalamic acetylcholine release in hemorrhage-hypotensive rats.

    PubMed

    Altinbas, Burcin; Yilmaz, Mustafa S; Savci, Vahide; Jochem, Jerzy; Yalcin, Murat

    2015-01-01

    Histamine, acting centrally as a neurotransmitter, evokes a reversal of hemorrhagic hypotension in rats due to the activation of the sympathetic and the renin-angiotensin systems as well as the release of arginine vasopressin and proopiomelanocortin-derived peptides. We demonstrated previously that central nicotinic cholinergic receptors are involved in the pressor effect of histamine. The aim of the present study was to examine influences of centrally administrated histamine on acetylcholine (ACh) release at the posterior hypothalamus-a region characterized by location of histaminergic and cholinergic neurons involved in the regulation of the sympathetic activity in the cardiovascular system-in hemorrhage-hypotensive anesthetized rats. Hemodynamic and microdialysis studies were carried out in Sprague-Dawley rats. Hemorrhagic hypotension was induced by withdrawal of a volume of 1.5 ml blood/100 g body weight over a period of 10 min. Acute hemorrhage led to a severe and long-lasting decrease in mean arterial pressure (MAP), heart rate (HR), and an increase in extracellular posterior hypothalamic ACh and choline (Ch) levels by 56% and 59%, respectively. Intracerebroventricularly (i.c.v.) administered histamine (50, 100, and 200 nmol) dose- and time-dependently increased MAP and HR and caused an additional rise in extracellular posterior hypothalamic ACh and Ch levels at the most by 102%, as compared to the control saline-treated group. Histamine H1 receptor antagonist chlorpheniramine (50 nmol; i.c.v.) completely blocked histamine-evoked hemodynamic and extracellular posterior hypothalamic ACh and Ch changes, whereas H2 and H3/H4 receptor blockers ranitidine (50 nmol; i.c.v.) and thioperamide (50 nmol; i.c.v.) had no effect. In conclusion, centrally administered histamine, acting via H1 receptors, increases ACh release at the posterior hypothalamus and causes a pressor and tachycardic response in hemorrhage-hypotensive anesthetized rats.

  3. Complications when augmenting the posterior maxilla.

    PubMed

    Fugazzotto, Paul; Melnick, Philip R; Al-Sabbagh, Mohanad

    2015-01-01

    The maxillary posterior edentulous region presents a challenge when planning for restoring missing teeth with a dental implant. The available bone in such cases is often not dense and not adequate for the placement of a properly sized implant because of maxillary sinus pneumatization and alveolar bone loss. Maxillary sinus lift is a predictable procedure to provide adequate bone height for the purpose of implant placement. However, complications are encountered during or after the execution of the sinus lift procedure. In this article, the prevention and management of maxillary sinus complications are discussed. PMID:25434561

  4. Quantum Operation Time Reversal

    SciTech Connect

    Crooks, Gavin E.

    2008-03-25

    The dynamics of an open quantum system can be described by a quantum operation: A linear, complete positive map of operators. Here, I exhibit a compact expression for the time reversal of a quantum operation, which is closely analogous to the time reversal of a classical Markov transition matrix. Since open quantum dynamics are stochastic, and not, in general, deterministic, the time reversal is not, in general, an inversion of the dynamics. Rather, the system relaxes toward equilibrium in both the forward and reverse time directions. The probability of a quantum trajectory and the conjugate, time reversed trajectory are related by the heat exchanged with the environment.

  5. Thematic role assignment in the posterior parietal cortex: A TMS study.

    PubMed

    Finocchiaro, Chiara; Capasso, Rita; Cattaneo, Luigi; Zuanazzi, Arianna; Miceli, Gabriele

    2015-10-01

    Verbs denote relations between entities acting a role in an event. Thematic roles are essential to the correct use of verbs and involve both semantic and syntactic aspects. We used repetitive Transcranial Magnetic Stimulation (rTMS) to study the involvement of three different left parietal sites in the understanding of thematic roles. In a sentence-to-picture matching task, twelve participants were asked to judge whether or not a given picture matched with a written sentence. Pictures represented simple reversible actions, and sentences were in the active or passive diathesis. Whereas both active and passive sentences require the correct encoding of thematic roles, passives also imply thematic reanalysis, as the canonical order of thematic roles is systematically reversed. The experiment was divided in three sessions. In each session a different parietal site (anterior, middle, posterior) was stimulated at 5 Hz in an event-related fashion, time-locked to the presentation of visual stimuli. Results showed increased accuracy for passive sentences following posterior parietal stimulation. The effect appeared to be (a) TMS-related, as no effect was observed in a control, no-TMS experiment with eighteen new participants; (b) independent from semantic processes involved in word-picture association, as no TMS-related effects were observed in a picture-word matching task. We interpret the results as showing that the posterior parietal site is specifically involved in the assignment of thematic roles, in particular when the correct interpretation of a sentence requires reanalysis of temporarily encoded thematic roles, as in passive reversible sentences.

  6. The posterior impingement sign: diagnosis of rotator cuff and posterior labral tears secondary to internal impingement in overhand athletes.

    PubMed

    Meister, Keith; Buckley, Bernadette; Batts, Joel

    2004-08-01

    We conducted this study to determine whether a test, the posterior impingement maneuver, could be used to prospectively identify articular side tears of the rotator cuff and/or posterior labrum. Sixty-nine athletes presented with posterior shoulder pain that developed during overhand athletics. Injured shoulders were placed into 90 degrees to 110 degrees of abduction, slight extension, and maximum external rotation, and an effort was made to elicit pain deep within the posterior aspect. Overall sensitivity of the test was 75.5%, and specificity was 85%. When only athletes with noncontact injuries (gradual onset of pain) were considered, sensitivity was 95% and specificity was 100%. A positive posterior impingement sign correlated highly with undersurface tearing of the rotator cuff and/or tearing of the posterior labrum in athletes with gradual onset of posterior shoulder pain during overhand athletics. PMID:15379239

  7. Posterior subcapsular cataract and inhaled corticosteroid therapy.

    PubMed Central

    Abuekteish, F.; Kirkpatrick, J. N.; Russell, G.

    1995-01-01

    BACKGROUND--Although posterior subcapsular cataract complicates both systemic and topical corticosteroid therapy, the literature on the effects of inhaled corticosteroids is conflicting. METHODS--One hundred and forty children and young adults on inhaled corticosteroids were examined by slit lamp ophthalmoscopy after pupillary dilatation; 103 had received one or more short courses (< or = 7 days) of oral corticosteroids in the management of acute asthmatic attacks and four had also received one or more prolonged courses (> or = 4 weeks) of alternate day oral corticosteroid therapy. RESULTS--Bilateral posterior subcapsular cataract was identified in one girl who had received several prolonged courses of oral corticosteroids, but was not identified in any other patient. CONCLUSIONS--There is no evidence to support the contention that inhaled corticosteroid therapy on its own, or in association with short courses of oral corticosteroid therapy, might cause cataracts. Although children receiving long term systemic corticosteroid therapy should be screened for cataracts, this is unnecessary in children on inhaled corticosteroids alone. PMID:7638813

  8. Sampling Networks from Their Posterior Predictive Distribution.

    PubMed

    Goyal, Ravi; De Gruttola, Victor; Blitzstein, Joseph

    2014-04-01

    Recent research indicates that knowledge about social networks can be leveraged to increase efficiency of interventions (Valente, 2012). However, in many settings, there exists considerable uncertainty regarding the structure of the network. This can render the estimation of potential effects of network-based interventions difficult, as providing appropriate guidance to select interventions often requires a representation of the whole network. In order to make use of the network property estimates to simulate the effect of interventions, it may be beneficial to sample networks from an estimated posterior predictive distribution, which can be specified using a wide range of models. Sampling networks from a posterior predictive distribution of network properties ensures that the uncertainty about network property parameters is adequately captured. The tendency for relationships among network properties to exhibit sharp thresholds has important implications for understanding global network topology in the presence of uncertainty; therefore, it is essential to account for uncertainty. We provide detail needed to sample networks for the specific network properties of degree distribution, mixing frequency, and clustering. Our methods to generate networks are demonstrated using simulated data and data from the National Longitudinal Study of Adolescent Health.

  9. Bladder neck incompetence at posterior urethroplasty.

    PubMed

    Koraitim, Mamdouh M

    2015-03-01

    The finding of an incompetent bladder neck (BN) at the time of posterior urethroplasty will necessarily exacerbate the already difficult situation. In such cases the aim of the treatment is not only to restore urethral continuity by end-to-end urethral anastomosis, but also to restore the function of the BN to maintain urinary continence. Fortunately, the incidence of incompetence of the BN at posterior urethroplasty is uncommon, usually ≈4.5%. It seems that pelvic fracture-related BN injuries, in contrast to urethral injuries which result from a shearing force, are due to direct injury by the sharp edge of the fractured and displaced pubic bone. The risk of injuries to the BN is greater in children, in patients with a fracture involving both superior and inferior pubic rami on the same side, and in those managed initially by primary realignment. An incompetent BN is suspected by finding an open rectangular BN on cystography, and a fixedly open BN on suprapubic cystoscopy. An incompetent BN can be treated either subsequent to or concomitant with the urethral repair, according to whether a perineal or a perineo-abdominal urethroplasty is used, respectively. Several options have been reported to treat pelvic fracture-related BN incompetence, including reconstructing the BN, forming a new sphincter by tubularisation of a rectangular flap of the anterior bladder wall, and mechanical occlusion by an artificial sphincter or collagen injection. Reconstruction of the BN by the Young-Dees-Leadbetter∗∗ procedure probably provides the most successful results.

  10. Posterior surgical approaches to the rectum.

    PubMed Central

    Westbrook, K C; Lang, N P; Broadwater, J R; Thompson, B W

    1982-01-01

    This report summarizes experience with 19 posterior approaches to the rectum including nine trans-sacral (Kraske) and ten trans-sphincteric (Mason) procedures. This study included 12 men and 7 women, ranging in age from 18 to 89 years. Surgical indications included villous tumors in nine patients, various benign problems in four patients, primary carcinomas in three patients, and recurrent cancer in three patients. Eight complications developed in the 19 patients including: four fecal fistulae, two wound dehiscences, one rectal stricture, and one sacrococcygeal hernia. Spontaneous closure of the fecal fistulae occurred in two patients, and two patients required proximal colostomies. Fecal continence was achieved in 18 of the 19 patients. No patient died as a complication of the procedure. No recurrent tumors have developed. The conclusion is that a posterior approach to the rectum is a safe and effective procedure for various benign and for selected malignant conditions. It is particularly suitable for villous tumors that are too high for transanal resection and too low for transabdominal resection. It is an effective procedure for small, exophytic, mobile carcinomas of the lower 10 cm of the rectum in selected patients. PMID:7082059

  11. Posterior femoral translation in medial pivot total knee arthroplasty of posterior cruciate ligament retaining type

    PubMed Central

    Cho, Su Hyun; Cho, Hyung Lae; Lee, Soo Ho; Jin, Hong Ki

    2013-01-01

    Purpose To report clinical results and demonstrate posterior femoral translation (PFT) in medial pivot total knee arthroplasty (TKA) of posterior cruciate ligament (PCL) retaining type. Materials and methods A prospective study was performed upon thirty consecutive subjects who were operated on with medial pivot TKA of PCL retaining type between March 2009 and March 2010 and had been followed up for at least 2 years. Clinically, the knee society knee score and function score were used. In full extension and active flexion lateral radiograph, anteroposterior (AP) condylar position and magnitude of PFT was determined. Results At last follow-up, the mean knee society knee score and function score improved significantly compared to preoperative scores. The AP condylar positions were consistently posterior to midline throughout the entire range of flexion. The PFTs averaged 0.31 (±0.12) of half length of tibial base plate and were greater in higher flexion cases (r = 0.56, p = 0.0012). There were no cases having either component migration or radiolucent line wider than 2 mm except for one case showing instability related to trauma. Conclusions In medial pivot TKA of PCL retaining type, clinical outcomes were satisfactory and posterior femoral translations were consistently observed during progressive flexions of knees at two- to three-year follow-up. PMID:24403754

  12. GNSS integer ambiguity validation based on posterior probability

    NASA Astrophysics Data System (ADS)

    Wu, Zemin; Bian, Shaofeng

    2015-10-01

    GNSS integer ambiguity validation is considered to be a challenge task for decades. Several kinds of validation tests are developed and widely used in these years, but theoretical basis is their weakness. Ambiguity validation theoretically is an issue of hypothesis test. In the frame of Bayesian hypothesis testing, posterior probability is the canonical standard that statistical decision should be based on. In this contribution, (i) we derive the posterior probability of the fixed ambiguity based on the Bayesian principle and modify it for practice ambiguity validation. (ii) The optimal property of the posterior probability test is proved based on an extended Neyman-Pearson lemma. Since validation failure rate is the issue users most concerned about, (iii) we derive the failure rate upper bound of the posterior probability test, so the user can use the posterior probability test either in the fixed posterior probability or in the fixed failure rate way. Simulated as well as real observed data are used for experimental validations. The results show that (i) the posterior probability test is the most effective within the R-ratio test, difference test, ellipsoidal integer aperture test and posterior probability test, (ii) the posterior probability test is computational efficient and (iii) the failure rate estimation for posterior probability test is useful.

  13. Anterior urethral valve associated with posterior urethral valves: report of 2 cases and review of the literature.

    PubMed

    Tran, Christine N; Reichard, Chad A; McMahon, Daniel; Rhee, Audrey

    2014-08-01

    Anterior urethral valve (AUV) associated with posterior urethral valves (PUVs) is an extremely rare congenital urologic anomaly resulting in lower urinary tract obstruction. We present our experience with 2 children with concomitant AUV and PUV as well as a literature review. The clinical presentation of concomitant AUV and PUV is variable. Successful endoscopic management can result in improvement in renal function, reversal of obstructive changes, and improvement or resolution of voiding dysfunction. PMID:24958476

  14. Biomechanical benefits of anterior offsetting of humeral head component in posteriorly unstable total shoulder arthroplasty: A cadaveric study.

    PubMed

    Kim, Hyun-Min Mike; Chacon, Alexander C; Andrews, Seth H; Roush, Evan P; Cho, Edward; Conaway, William K; Kunselman, Allen R; Lewis, Gregory S

    2016-04-01

    Restoration of joint stability during total shoulder arthroplasty can be challenging in the face of severe glenoid retroversion. A novel technique of humeral head component anterior-offsetting has been proposed to address posterior instability. We evaluated the biomechanical benefits of this technique in cadaveric specimens. Total shoulder arthroplasty was performed in 14 cadaveric shoulders from 7 donors. Complementary shoulders were assigned to either 10° or 20° glenoid retroversion, with retroversion created by eccentric reaming. Two humeral head component offset positions were tested in each specimen: The anatomic (posterior) and anterior (reverse). With loads applied to the rotator cuff and deltoid, joint contact pressures and the force and energy required for posterior humeral head translation were measured. The force and energy required to displace the humeral head posteriorly increased significantly with the anterior offset position compared to the anatomic offset position. The joint contact pressures were significantly shifted anteriorly, and the joint contact area significantly increased with the anterior offset position. Anterior offsetting of the humeral head component increased the resistance to posterior humeral head translation, shifted joint contact pressures anteriorly, and increased joint contact area, thus, potentially increasing the joint stability in total shoulder arthroplasty with simulated glenoid retroversion. PMID:26356804

  15. Reversing expectations during discourse comprehension

    PubMed Central

    Xiang, Ming; Kuperberg, Gina

    2014-01-01

    In two ERP experiments, we asked whether comprehenders used the concessive connective, even so, to predict upcoming events. Participants read coherent and incoherent scenarios, with and without even so, e.g. “Elizabeth had a history exam on Monday. She took the test and aced/failed it. (Even so), she went home and celebrated wildly.”, as they rated coherence (Experiment 1) or simply answered intermittent comprehension questions (Experiment 2). The semantic function of even so was used to reverse real-world knowledge predictions, leading to an attenuated N400 to coherent versus incoherent target words (“celebrated”). Moreover, its pragmatic communicative function enhanced predictive processing, leading to more N400 attenuation to coherent targets in scenarios with than without even so. This benefit however, did not come for free: the detection of failed event predictions triggered a later posterior positivity and/or an anterior negativity effect, and costs of maintaining alternative likelihood relations manifest as a sustained negativity effect on sentence-final words. PMID:25914891

  16. Vasectomy reversal in humans.

    PubMed

    Bernie, Aaron M; Osterberg, E Charles; Stahl, Peter J; Ramasamy, Ranjith; Goldstein, Marc

    2012-10-01

    Vasectomy is the most common urological procedure in the United States with 18% of men having a vasectomy before age 45. A significant proportion of vasectomized men ultimately request vasectomy reversal, usually due to divorce and/or remarriage. Vasectomy reversal is a commonly practiced but technically demanding microsurgical procedure that restores patency of the male excurrent ductal system in 80-99.5% of cases and enables unassisted pregnancy in 40-80% of couples. The discrepancy between the anastomotic patency rates and clinical pregnancy rates following vasectomy reversal suggests that some of the biological consequences of vasectomy may not be entirely reversible in all men. Herein we review what is known about the biological sequelae of vasectomy and vasectomy reversal in humans, and provide a succinct overview of the evaluation and surgical management of men desiring vasectomy reversal.

  17. Evaluation and management of posterior ankle pain in dancers.

    PubMed

    Luk, Pamela; Thordarson, David; Charlton, Timothy

    2013-01-01

    Posterior ankle pain is a common complaint in dancers. There are multiple structures in the posterior ankle that have the potential to be the source of pain. The objective of this article is to review several of the most common causes of posterior ankle pain: peroneal tendon subluxation, posterior impingement syndrome secondary to a painful os trigonum, posterior talus osteochondritis dissecans, flexor hallucis longus tendinopathy, and posterior tibial tendinopathy. For dancers, we offer typical clinical presentations of these disorders to increase awareness and provide guidance regarding when to seek professional medical attention. For medical personnel who are responsible for optimizing dancers' health and training, we include a discussion of pertinent physical exam findings, diagnostic imaging options, non-operative and operative management, as well as surgical suggestions and postoperative rehabilitation guidelines.

  18. Iodine-125 radiation of posterior uveal melanoma

    SciTech Connect

    Packer, S.

    1987-12-01

    Twenty-eight cases of posterior choroidal melanoma were treated with iodine-125 in gold eye plaques. Eleven cases were located within 3.0 mm of the optic nerve (group A), nine were within 3.0 mm of the fovea (group B), and eight were within 3.0 mm of the optic nerve and fovea (group C). The mean follow-up of group A was 46.3 months; group B, 25.5 months; and group C, 42.7 months. Complications included macular edema, cataract and tumor growth. Visual acuity remained within two lines of that tested preoperatively for 4 of 11 patients in group A, 4 of 9 in group B, and 5 of 8 in group C. These results with iodine-125 suggest it as an appropriate treatment for patients with choroidal melanoma located near optic nerve and/or macula.

  19. Posterior Cruciate Ligament: Focus on Conflicting Issues

    PubMed Central

    Lee, Yong Seuk

    2013-01-01

    There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed. PMID:24340144

  20. Paediatric intrasubstance posterior cruciate ligament rupture.

    PubMed

    Scott, Chloe E H; Murray, Alastair W

    2011-01-01

    The authors present the case of a 4-year-old boy who sustained an intrasubstance posterior cruciate ligament (PCL) tear whist trampolining. He was managed non-operatively with return to full function by 8 months. A high index of suspicion is required when assessing paediatric hyperflexion/extension injuries at the knee as ligamentous injury may occur without osteochondral fracture and may be missed on routine radiographs. Early MRI can identify such injuries in addition to osteochondral avulsions which are often amenable to acute internal fixation. In the case of paediatric intrasubstance PCL tears, it appears that non-operative management yields a good functional outcome in the short term in the skeletally immature.

  1. Posterior cruciate ligament: focus on conflicting issues.

    PubMed

    Lee, Yong Seuk; Jung, Young Bok

    2013-12-01

    There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed.

  2. Posterior restorations--a clinical view.

    PubMed

    Jedynakiewicz, N M; Martin, N

    2001-01-01

    This paper examines the state-of-the-art in the direct restoration of posterior teeth. The existing paradigms for the management of caries are questioned and some existing methods of cavity preparation are reviewed. Dental restorations need to be durable but able to adapt to a changing environment brought about by wear of the adjacent tooth substance and by fatigue processes within the tooth itself. The wear of restorative materials needs to be matched to that of the tooth, otherwise differential loss of either the restorative material or the enamel may destabilize the occlusion. Esthetic instability due to natural darkening of the tooth with age, punctuated by clinical intervention with bleaching procedures, adds a further dimension to the concept of a permanent restoration. Clinical methods that minimize the disruptive effects of dental restorations upon the remaining tooth structure are a continuing challenge.

  3. Hemifacial spasm and posterior auricular muscle.

    PubMed

    Kiziltan, M; Sahin, R; Uzun, N; Kiziltan, G

    2006-09-01

    We aimed to investigate to which extent posterior auricular muscle (PAM) was affected and whether it contributed to the reflex activity in hemifacial spasm (HFS) patients. 19 HFS patients' spasm activities were recorded from facial muscles. Spasm activity of PAM was recorded synchronously on the symptomatic side in all patients. Lateral spread of blink reflex to orbicularis oris and PAMs were recorded in all but two patients. Botulinum toxin was applied to the PAM with the 14 patients presenting tinnitus, "clicking" or a "ticking" sound on the sane side and other positive auricular symptoms. After treatment, there was symptomatic improvement in 9 of 14 patients. The patients presenting with auricular symptoms and showing spasm activity in their PAMs can be thought as a candidate for botulinum toxin treatment scheme.

  4. Bladder neck incompetence at posterior urethroplasty

    PubMed Central

    Koraitim, Mamdouh M.

    2015-01-01

    The finding of an incompetent bladder neck (BN) at the time of posterior urethroplasty will necessarily exacerbate the already difficult situation. In such cases the aim of the treatment is not only to restore urethral continuity by end-to-end urethral anastomosis, but also to restore the function of the BN to maintain urinary continence. Fortunately, the incidence of incompetence of the BN at posterior urethroplasty is uncommon, usually ≈4.5%. It seems that pelvic fracture-related BN injuries, in contrast to urethral injuries which result from a shearing force, are due to direct injury by the sharp edge of the fractured and displaced pubic bone. The risk of injuries to the BN is greater in children, in patients with a fracture involving both superior and inferior pubic rami on the same side, and in those managed initially by primary realignment. An incompetent BN is suspected by finding an open rectangular BN on cystography, and a fixedly open BN on suprapubic cystoscopy. An incompetent BN can be treated either subsequent to or concomitant with the urethral repair, according to whether a perineal or a perineo-abdominal urethroplasty is used, respectively. Several options have been reported to treat pelvic fracture-related BN incompetence, including reconstructing the BN, forming a new sphincter by tubularisation of a rectangular flap of the anterior bladder wall, and mechanical occlusion by an artificial sphincter or collagen injection. Reconstruction of the BN by the Young-Dees-Leadbetter∗∗ procedure probably provides the most successful results. PMID:26019982

  5. Simultaneous correction of functional posterior cross bite and midline shift

    PubMed Central

    Arvinth, R.; Rana, Shailendra Singh; Duggal, Ritu; Kharbanda, Om Prakash

    2016-01-01

    The most frequent cause of functional posterior crossbite is the reduction in width of the maxillary dental arch. This posterior crossbite is associated with anterior crowding which is presented as an infrapositioned canine or a palatally positioned lateral incisor on one side; this leads to an upper midline shift toward the crowded side. The present case report shows the management of posterior crossbite with functional shift and upper midline shift simultaneously without adverse side effects. In this case, rapid maxillary expansion along with fixed appliance is used to correct posterior crossbite with the upper dental midline shift using reciprocal action of elastic transseptal fibers.

  6. Simultaneous correction of functional posterior cross bite and midline shift

    PubMed Central

    Arvinth, R.; Rana, Shailendra Singh; Duggal, Ritu; Kharbanda, Om Prakash

    2016-01-01

    The most frequent cause of functional posterior crossbite is the reduction in width of the maxillary dental arch. This posterior crossbite is associated with anterior crowding which is presented as an infrapositioned canine or a palatally positioned lateral incisor on one side; this leads to an upper midline shift toward the crowded side. The present case report shows the management of posterior crossbite with functional shift and upper midline shift simultaneously without adverse side effects. In this case, rapid maxillary expansion along with fixed appliance is used to correct posterior crossbite with the upper dental midline shift using reciprocal action of elastic transseptal fibers. PMID:27630513

  7. Diagnostics for insufficiencies of posterior calculations in Bayesian signal inference.

    PubMed

    Dorn, Sebastian; Oppermann, Niels; Ensslin, Torsten A

    2013-11-01

    We present an error-diagnostic validation method for posterior distributions in Bayesian signal inference, an advancement of a previous work. It transfers deviations from the correct posterior into characteristic deviations from a uniform distribution of a quantity constructed for this purpose. We show that this method is able to reveal and discriminate several kinds of numerical and approximation errors, as well as their impact on the posterior distribution. For this we present four typical analytical examples of posteriors with incorrect variance, skewness, position of the maximum, or normalization. We show further how this test can be applied to multidimensional signals.

  8. Simultaneous correction of functional posterior cross bite and midline shift.

    PubMed

    Arvinth, R; Rana, Shailendra Singh; Duggal, Ritu; Kharbanda, Om Prakash

    2016-01-01

    The most frequent cause of functional posterior crossbite is the reduction in width of the maxillary dental arch. This posterior crossbite is associated with anterior crowding which is presented as an infrapositioned canine or a palatally positioned lateral incisor on one side; this leads to an upper midline shift toward the crowded side. The present case report shows the management of posterior crossbite with functional shift and upper midline shift simultaneously without adverse side effects. In this case, rapid maxillary expansion along with fixed appliance is used to correct posterior crossbite with the upper dental midline shift using reciprocal action of elastic transseptal fibers. PMID:27630513

  9. Posterior Parietal Cortex Drives Inferotemporal Activations During Three-Dimensional Object Vision

    PubMed Central

    Van Dromme, Ilse C.; Premereur, Elsie; Verhoef, Bram-Ernst; Vanduffel, Wim; Janssen, Peter

    2016-01-01

    The primate visual system consists of a ventral stream, specialized for object recognition, and a dorsal visual stream, which is crucial for spatial vision and actions. However, little is known about the interactions and information flow between these two streams. We investigated these interactions within the network processing three-dimensional (3D) object information, comprising both the dorsal and ventral stream. Reversible inactivation of the macaque caudal intraparietal area (CIP) during functional magnetic resonance imaging (fMRI) reduced fMRI activations in posterior parietal cortex in the dorsal stream and, surprisingly, also in the inferotemporal cortex (ITC) in the ventral visual stream. Moreover, CIP inactivation caused a perceptual deficit in a depth-structure categorization task. CIP-microstimulation during fMRI further suggests that CIP projects via posterior parietal areas to the ITC in the ventral stream. To our knowledge, these results provide the first causal evidence for the flow of visual 3D information from the dorsal stream to the ventral stream, and identify CIP as a key area for depth-structure processing. Thus, combining reversible inactivation and electrical microstimulation during fMRI provides a detailed view of the functional interactions between the two visual processing streams. PMID:27082854

  10. Justice and Reverse Discrimination.

    ERIC Educational Resources Information Center

    Goldman, Alan H.

    Defining reverse discrimination as hiring or admissions decisions based on normally irrelevant criteria, this book develops principles of rights, compensation, and equal opportunity applicable to the reverse discrimination issue. The introduction defines the issue and discusses deductive and inductive methodology as applied to reverse…

  11. Quantum reverse hypercontractivity

    SciTech Connect

    Cubitt, Toby; Kastoryano, Michael; Montanaro, Ashley; Temme, Kristan

    2015-10-15

    We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.

  12. Reverse Discrimination: Recent Cases.

    ERIC Educational Resources Information Center

    Steinhilber, August W.

    This paper discusses reverse discrimination cases with particular emphasis on Bakke v. Regents of University of California and those cases which preceded it. A brief history is given of court cases used by opponents and proponents in the discussion of reverse discrimination. Legal theory and a discussion of court cases that preceded Bakke follow.…

  13. The "Sublabral Window" in Arthroscopic Posterior Shoulder Instability Surgery: Description of a Technique for Safe Posterior Glenoid Preparation.

    PubMed

    Patel, Kushal V; Bravman, Jonathan T; McCarty, Eric

    2016-06-01

    Arthroscopic posterior labral repairs for posterior shoulder instability can be challenging. Preparation of the capsulolabral tissue and glenoid bony surface is critical. Iatrogenic injury to the articular cartilage and unwarranted truncation of the capsulolabral tissue are concerns during preparation. As a result, several techniques have been described to potentially avoid these complications. We describe an additional technique for improving access and preparing the capsulolabral tissue and glenoid surface through a "sublabral window." This technique approaches the posterior labrum and glenoid through an already established posterior portal and mitigates iatrogenic injury to the labrum and articular cartilage. The technique is rather simple and easily adaptable. PMID:27656358

  14. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  15. Posterior regeneration in Isodiametra pulchra (Acoela, Acoelomorpha)

    PubMed Central

    2013-01-01

    Introduction Regeneration is a widespread phenomenon in the animal kingdom, but the capacity to restore damaged or missing tissue varies greatly between different phyla and even within the same phylum. However, the distantly related Acoelomorpha and Platyhelminthes share a strikingly similar stem-cell system and regenerative capacity. Therefore, comparing the underlying mechanisms in these two phyla paves the way for an increased understanding of the evolution of this developmental process. To date, Isodiametra pulchra is the most promising candidate as a model for the Acoelomorpha, as it reproduces steadily under laboratory conditions and is amenable to various techniques, including the silencing of gene expression by RNAi. In order to provide an essential framework for future studies, we report the succession of regeneration events via the use of cytochemical, histological and microscopy techniques, and specify the total number of cells in adult individuals. Results Isodiametra pulchra is not capable of regenerating a new head, but completely restores all posterior structures within 10 days. Following amputation, the wound closes via the contraction of local muscle fibres and an extension of the dorsal epidermis. Subsequently, stem cells and differentiating cells invade the wound area and form a loosely delimited blastema. After two days, the posterior end is re-patterned with the male (and occasionally the female) genital primordium being apparent. Successively, these primordia differentiate into complete copulatory organs. The size of the body and also of the male and female copulatory organs, as well as the distance between the copulatory organs, progressively increase and by nine days copulation is possible. Adult individuals with an average length of 670 μm consist of approximately 8100 cells. Conclusion Isodiametra pulchra regenerates through a combination of morphallactic and epimorphic processes. Existing structures are “re-modelled” and provide a

  16. Posterior Tibialis Tendon Dysfunction: Overview of Evaluation and Management.

    PubMed

    Yao, Kaihan; Yang, Timothy Xianyi; Yew, Wei Ping

    2015-06-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Recognize posterior tibialis tendon dysfunction and begin to include it in differential diagnoses. 2. Recall the basic anatomy and pathology of the posterior tibialis tendon. 3. Assess a patient for posterior tibialis tendon dysfunction with the appropriate investigations and stratify the severity of the condition. 4. Develop and formulate a treatment plan for a patient with posterior tibialis tendon dysfunction. The posterior tibialis is a muscle in the deep posterior compartment of the calf that plays several key roles in the ankle and foot. Posterior tibialis tendon dysfunction is a complex but common and debilitating condition. Degenerative, inflammatory, functional, and traumatic etiologies have all been proposed. Despite being the leading cause of acquired flatfoot, it is often not recognized early enough. Knowledge of the anatomical considerations and etiology of posterior tibialis tendon dysfunction, as well as key concepts in its evaluation and management, will allow health care professionals to develop appropriate intervention strategies to prevent further development of flatfoot deformities. PMID:26091214

  17. Role of posterior hypothalamus in hypobaric hypoxia induced pulmonary edema.

    PubMed

    Sharma, R K; Choudhary, R C; Reddy, M K; Ray, A; Ravi, K

    2015-01-01

    To investigate the role of posterior hypothalamus and central neurotransmitters in the pulmonary edema due to hypobaric hypoxia, rats were placed in a high altitude simulation chamber (barometric pressure-294.4 mmHg) for 24 h. Exposure to hypobaric hypoxia resulted in increases in mean arterial blood pressure, renal sympathetic nerve activity, right ventricular systolic pressure, lung wet to dry weight ratio and Evans blue dye leakage. There was a significant attenuation in these responses to hypobaric hypoxia (a) after lesioning posterior hypothalamus and (b) after chronic infusion of GABAA receptor agonist muscimol into posterior hypothalamus. No such attenuation was evident with the chronic infusion of the nitric oxide donor SNAP into the posterior hypothalamus. It is concluded that in hypobaric hypoxia, there is over-activity of posterior hypothalamic neurons probably due to a local decrease in GABA-ergic inhibition which increases the sympathetic drive causing pulmonary hypertension and edema. PMID:25448396

  18. Facilitating text reading in posterior cortical atrophy

    PubMed Central

    Rajdev, Kishan; Shakespeare, Timothy J.; Leff, Alexander P.; Crutch, Sebastian J.

    2015-01-01

    Objective: We report (1) the quantitative investigation of text reading in posterior cortical atrophy (PCA), and (2) the effects of 2 novel software-based reading aids that result in dramatic improvements in the reading ability of patients with PCA. Methods: Reading performance, eye movements, and fixations were assessed in patients with PCA and typical Alzheimer disease and in healthy controls (experiment 1). Two reading aids (single- and double-word) were evaluated based on the notion that reducing the spatial and oculomotor demands of text reading might support reading in PCA (experiment 2). Results: Mean reading accuracy in patients with PCA was significantly worse (57%) compared with both patients with typical Alzheimer disease (98%) and healthy controls (99%); spatial aspects of passages were the primary determinants of text reading ability in PCA. Both aids led to considerable gains in reading accuracy (PCA mean reading accuracy: single-word reading aid = 96%; individual patient improvement range: 6%–270%) and self-rated measures of reading. Data suggest a greater efficiency of fixations and eye movements under the single-word reading aid in patients with PCA. Conclusions: These findings demonstrate how neurologic characterization of a neurodegenerative syndrome (PCA) and detailed cognitive analysis of an important everyday skill (reading) can combine to yield aids capable of supporting important everyday functional abilities. Classification of evidence: This study provides Class III evidence that for patients with PCA, 2 software-based reading aids (single-word and double-word) improve reading accuracy. PMID:26138948

  19. New infectious etiologies for posterior uveitis.

    PubMed

    Khairallah, Moncef; Kahloun, Rim; Ben Yahia, Salim; Jelliti, Bechir; Messaoud, Riadh

    2013-01-01

    Emergent and resurgent arthropod vector-borne diseases are major causes of systemic morbidity and death and expanding worldwide. Among them, viral and bacterial agents including West Nile virus, Dengue fever, Chikungunya, Rift Valley fever, and rickettsioses have been recently associated with an array of ocular manifestations. These include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by the detection of a specific antibody in serum. Ocular involvement associated with emergent infections usually has a self-limited course, but it can result in persistent visual impairment. There is currently no proven specific treatment for arboviral diseases, and therapy is mostly supportive. Vaccination for humans against these viruses is still in the research phase. Doxycycline is the treatment of choice for rickettsial diseases. Prevention, including public measures to reduce the number of mosquitoes and personal protection, remains the mainstay for arthropod vector disease control. Influenza A (H1N1) virus was responsible for a pandemic human influenza in 2009, and was recently associated with various posterior segment changes.

  20. Reversing the arms race

    SciTech Connect

    von Hippel, F. ); Sagdeev, R.Z. )

    1992-01-01

    This paper contains proceedings of Reversing The Arms Race. Topics covered include: Verifying Reductions of Nuclear Warheads; Verifying Limits on Nuclear-Armed Cruise Missiles; and The Technical Basis for Warhead Detection.

  1. Reversibility of antibiotic resistance

    PubMed Central

    2014-01-01

    Although theoretically attractive, the reversibility of resistance has proven difficult in practice, even though antibiotic resistance mechanisms induce a fitness cost to the bacterium. Associated resistance to other antibiotics and compensatory mutations seem to ameliorate the effect of antibiotic interventions in the community. In this paper the current understanding of the concepts of reversibility of antibiotic resistance and the interventions performed in hospitals and in the community are reviewed. PMID:24836051

  2. Adaptive Pairing Reversible Watermarking.

    PubMed

    Dragoi, Ioan-Catalin; Coltuc, Dinu

    2016-05-01

    This letter revisits the pairwise reversible watermarking scheme of Ou et al., 2013. An adaptive pixel pairing that considers only pixels with similar prediction errors is introduced. This adaptive approach provides an increased number of pixel pairs where both pixels are embedded and decreases the number of shifted pixels. The adaptive pairwise reversible watermarking outperforms the state-of-the-art low embedding bit-rate schemes proposed so far.

  3. Posterior Cruciate Ligament Retention versus Posterior Stabilization for Total Knee Arthroplasty: A Meta-Analysis

    PubMed Central

    Wang, Ying; Bian, Yanyan; Feng, Bin; Weng, Xisheng

    2016-01-01

    Introduction Although being debated for many years, the superiority of posterior cruciate-retaining (CR) total knee arthroplasty (TKA) and posterior-stabilized (PS) TKA remains controversial. We compare the knee scores, post-operative knee range of motion (ROM), radiological outcomes about knee kinematic and complications between CR TKA and PS TKA. Methods Literature published up to August 2015 was searched in PubMed, Embase and Cochrane databases, and meta-analysis was performed using the software, Review Manager version 5.3. Results Totally 14 random control trials (RCTs) on this topic were included for the analysis, which showed that PS and CR TKA had no significant difference in Knee Society knee Score (KSS), pain score (KSPS), Hospital for Special Surgery score (HSS), kinematic characteristics including postoperative component alignment, tibial posterior slope and joint line, and complication rate. However, PS TKA is superior to CR TKA regarding post-operative knee range of motion (ROM) [Random Effect model (RE), Mean Difference (MD) = -7.07, 95% Confidential Interval (CI) -10.50 to -3.65, p<0.0001], improvement of ROM (Fixed Effect model (FE), MD = -5.66, 95% CI -10.79 to -0.53, p = 0.03) and femoral-tibial angle [FE, MD = 0.85, 95% CI 0.46 to 1.25, p<0.0001]. Conclusions There are no clinically relevant differences between CR and PS TKA in terms of clinical, functional, radiological outcome, and complications, while PS TKA is superior to CR TKA in respects of ROM, while whether this superiority matters or not in clinical practice still needs further investigation and longer follow-up. PMID:26824368

  4. Arthroscopic Repair of Posterior Meniscal Root Tears

    PubMed Central

    Matheny, Lauren; Moulton, Samuel G.; Dean, Chase S.; LaPrade, Robert F.

    2016-01-01

    Objectives: The purpose of this study was to compare subjective clinical outcomes in patients requiring arthroscopic transtibial pullout repair for posterior meniscus root tears of the medial and lateral menisci. We hypothesized that improvement in function and activity level would be similar among patients undergoing lateral and medial meniscal root repairs. Methods: This study was IRB approved. All patients who underwent posterior meniscal root repair by a single orthopaedic surgeon were included in this study. Detailed operative data were documented at surgery. Patients completed a subjective questionnaire, including Lysholm score, Tegner activity scale, WOMAC, SF-12 and patient satisfaction with outcome, which were collected preoperatively and at a minimum of two years postoperatively. Failure was defined as any patient who underwent revision meniscal root repair or partial meniscectomy following the index surgery. Results: There were 50 patients (16 females, 34 males) with a mean age of 37.8 years (range, 16.6-65.7) and a mean BMI of 27.3 (range, 20.5-49.2) included in this study. Fifteen patients underwent lateral meniscus root repair and 35 patients underwent medial meniscus root repair. Three patients who underwent lateral meniscus root repair required revision meniscus root repair surgery, while no patients who underwent medial meniscus root repair required revision surgery (p=0.26). There was a significant difference in preoperative and postoperative Lysholm score (53 vs. 78) (p<0.001), Tegner activity scale (2.0 vs. 4.0) (p=0.03), SF-12 physical component subscale (38 vs. 50) (p=0.001) and WOMAC (36 vs. 8) (p<0.001) for the total population. Median patient satisfaction with outcome was 9 (range, 1-10). There was no significant difference in mean age between lateral and medial root repair groups (32 vs. 40) (p=0.12) or gender (p=0.19). There was no significant difference in gender between lateral and medial root repair groups (p=0.95). There was a

  5. Posterior spinal fusion using pedicle screws.

    PubMed

    Athanasakopoulos, Michael; Mavrogenis, Andreas F; Triantafyllopoulos, George; Koufos, Spiros; Pneumaticos, Spiros G

    2013-07-01

    Few clinical studies have reported polyetheretherketone (PEEK) rod pedicle screw spinal instrumentation systems (CD-Horizon Legacy PEEK rods; Medtronic, Minneapolis, Minnesota). This article describes a clinical series of 52 patients who underwent posterior spinal fusion using the PEEK Rod System between 2007 and 2010. Of the 52 patients, 25 had degenerative disk disease, 10 had lateral recess stenosis, 6 had degenerative spondylolisthesis, 6 had lumbar spine vertebral fracture, 4 had combined lateral recess stenosis and degenerative spondylolisthesis, and 1 had an L5 giant cell tumor. Ten patients had 1-segment fusion, 29 had 2-segment fusion, and 13 had 3-segment fusion. Mean follow-up was 3 years (range, 1.5-4 years); no patient was lost to follow-up. Clinical evaluation was performed using the Oswestry Disability Index and a low back and leg visual analog pain scale. Imaging evaluation of fusion was performed with standard and dynamic radiographs. Complications were recorded. Mean Oswestry Disability Index scores improved from 76% preoperatively (range, 52%-90%) to 48% at 6 weeks postoperatively, and to 34%, 28%, and 30% at 3, 6, and 12 months postoperatively, respectively. Mean low back and leg pain improved from 8 and 9 points preoperatively, respectively, to 6 and 5 points immediately postoperatively, respectively, and to 2 points each thereafter. Imaging union of the arthrodesis was observed in 50 (96%) patients by 1-year follow-up. Two patients sustained screw breakage: 1 had painful loss of sagittal alignment of the lumbar spine and underwent revision spinal surgery with pedicle screws and titanium rods and the other had superficial wound infection and was treated with wound dressing changes and antibiotics for 6 weeks. No adjacent segment degeneration was observed in any patient until the time of this writing. PMID:23823055

  6. Posterior ankle impingement syndrome: A systematic four-stage approach

    PubMed Central

    Yasui, Youichi; Hannon, Charles P; Hurley, Eoghan; Kennedy, John G

    2016-01-01

    Posterior ankle impingement syndrome (PAIS) is a common injury in athletes engaging in repetitive plantarflexion, particularly ballet dancers and soccer players. Despite the increase in popularity of the posterior two-portal hindfoot approach, concerns with the technique remain, including; the technical difficulty, relatively steep learning curve, and difficulty performing simultaneous anterior ankle arthroscopy. The purpose of the current literature review is to provide comprehensive knowledge about PAIS, and to describe a systematic four-stage approach of the posterior two-portal arthroscopy. The etiology, clinical presentation, diagnostic strategies are first introduced followed by options in conservative and surgical management. A detailed systematic approach to posterior hindfoot arthroscopy is then described. This technique allows for systematic review of the anatomic structures and treatment of the bony and/or soft tissue lesions in four regions of interest in the hindfoot (superolateral, superomedial, inferomedial, and inferolateral). The review then discusses biological adjuncts and postoperative rehabilitation and ends with a discussion on the most recent clinical outcomes after posterior hindfoot arthroscopy for PAIS. Although clinical evidence suggests high success rates following posterior hindfoot arthroscopy in the short- and mid-term it may be limited in the pathology that can be addressed due to the technical skills required, but the systematic four-stage approach of the posterior two-portal arthroscopy may improve upon this problem. PMID:27795947

  7. Posterior Cruciate Ligament Reconstruction in Patients with Generalized Joint Laxity

    PubMed Central

    Kim, Sung-Jae; Chang, Ji-Hoon

    2008-01-01

    Generalized joint laxity has been considered a risk factor causing late failure of reconstructed anterior cruciate ligaments, although it is unknown whether that is the case for reconstructed posterior cruciate ligaments. We hypothesized patients with generalized joint laxity, compared with those without laxity, would have similar postoperative knee stability, range of motion, and functional scores after posterior cruciate ligament reconstruction. The Beighton and Horan criteria were used to determine generalized joint laxity. We enrolled 24 patients with generalized joint laxity (Group L) and 29 patients without any positive findings of joint laxity (Group N) matched by gender and age. The average side-by-side differences of posterior tibial translation were 4.72 mm in Group L and 3.63 mm in Group N. We observed no differences in posterior tibial translation with differing graft materials or combined procedures. In Group L the International Knee Documentation Committee score was normal in 12.5% and nearly normal in 45.8% whereas in Group N, 24.1% were normal and 55.2% nearly normal. Patients with generalized joint laxity showed more posterior laxity than patients without joint laxity. Generalized joint laxity therefore appears to be a risk factor associated with posterior laxity after posterior cruciate ligament reconstruction. Level of Evidence: Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18843524

  8. On thermodynamic and microscopic reversibility

    SciTech Connect

    Crooks, Gavin E.

    2011-07-12

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

  9. Posterior mediastinal mass diagnosed as schwanomma with concomittant tuberculosis

    PubMed Central

    Tripathi, Surya Kant; Mishra, Ashwini Kumar; Verma, Ajay Kumar; Prakash, Ved

    2014-01-01

    A 21-year-old non-smoker, non-hypertensive male without diabetes was referred to our pulmonary medicine department with suspected malignant intrathoracic mass. The clinicoradiological evaluation revealed that it could be a posterior mediastinal mass. The same diagnosis was confirmed on performing CT and MRI. Benign posterior mediastinal schwanomma was suspected as it is the most common posterior mediastinal mass. It was completely resected. Histopathological examination confirmed the same. The mass was also sent for culture for mycobacterium which came out to be positive. The patient recovered from the surgery and postoperative X-ray showed complete clearance. He was treated with antitubercular treatment and responded very well. PMID:25246469

  10. Incidence and surgical importance of the posterior gastric artery.

    PubMed Central

    Suzuki, K; Prates, J C; DiDio, L J

    1978-01-01

    In a series of 61 adult cadavers, the posterior gastric artery was found in 38 (62.3%), originating from the superior aspect of the mid-third of the splenic artery. The posterior gastric artery, running behind the parietal peritoneum of the omental bursa, produced a peritoneal fold before reaching the posterior wall of the superior portion of the gastric body, near the cardiac region, and the fundus. Its high incidence, hidden origin, deep course, and distribution make this artery very important for surgical procedures relating to the stomach, pancreas, spleen, and celiac region. It may be crucial, especially if partial gastric resection of splenectomy have obliterated other gastric vessels. PMID:629615

  11. Asystole during posterior fossa surgery: Report of two cases

    PubMed Central

    Goyal, Keshav; Philip, Frenny Ann; Rath, Girija Prasad; Mahajan, Charu; Sujatha, M.; Bharti, Sachidanand Jee; Gupta, Nidhi

    2012-01-01

    Asystole during posterior fossa neurosurgical procedures is not uncommon. Various causes have been implicated, especially when surgical manipulation is carried out in the vicinity of the brain stem. The trigemino-cardiac reflex has been attributed as one of the causes. Here, we report two cases who suffered asystole during the resection of posterior fossa tumors. The vago-glossopharyngeal reflex and the direct stimulation of the brainstem were hypothesized as the causes of asytole. These episodes resolved spontaneously following withdrawal of the surgical stimulus emphasizing the importance of anticipation and vigilance during critical moments of tumor dissection during posterior fossa surgery. PMID:22870159

  12. The Simultaneous Modeling Technique: closing gaps in posteriors.

    PubMed

    Scolavino, Salvatore; Paolone, Gaetano; Orsini, Giovanna; Devoto, Walter; Putignano, Angelo

    2016-01-01

    Direct posterior restorations represent a widespread procedure in daily practice. Occlusal layering is often considered a complex task, generally not predictable and often requiring several occlusal adjustments. Moreover, direct posterior restorations are time consuming, as many small increments must be applied and cured individually to control shrinkage stress. Several authors have proposed different material layering techniques for posteriors. The authors of this article propose a simplified approach, which primarily aims to help the clinician perform quick, simple, predictable, and natural-looking occlusal modeling, reducing the need for occlusal adjustments.

  13. Posterior cortical atrophy: an atypical variant of Alzheimer disease.

    PubMed

    Suárez-González, Aida; Henley, Susie M; Walton, Jill; Crutch, Sebastian J

    2015-06-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by striking progressive visual impairment and a pattern of atrophy mainly involving posterior cortices. PCA is the most frequent atypical presentation of Alzheimer disease. The purpose of this article is to provide a summary of PCA's neuropsychiatric manifestations. Emotional and psychotic symptoms are discussed in the context of signal characteristic features of the PCA syndrome (the early onset, focal loss of visual perception, focal posterior brain atrophy) and the underlying cause of the disease. The authors' experience with psychotherapeutic intervention and PCA support groups is shared in detail.

  14. Anatomic Double-Bundle Posterior Cruciate Ligament Reconstruction.

    PubMed

    Chahla, Jorge; Nitri, Marco; Civitarese, David; Dean, Chase S; Moulton, Samuel G; LaPrade, Robert F

    2016-02-01

    The posterior cruciate ligament (PCL) is known to be the main posterior stabilizer of the knee. Anatomic single-bundle PCL reconstruction, focusing on reconstruction of the larger anterolateral bundle, is the most commonly performed procedure. Because of the residual posterior and rotational tibial instability after the single-bundle procedure and the inability to restore the normal knee kinematics, an anatomic double-bundle PCL reconstruction has been proposed in an effort to re-create the native PCL footprint more closely and to restore normal knee kinematics. We detail our technique for an anatomic double-bundle PCL reconstruction using Achilles and anterior tibialis tendon allografts. PMID:27284530

  15. Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mitchell, Justin J.; Dean, Chase S.; Chahla, Jorge; Menge, Travis J.; Cram, Tyler R.; LaPrade, Robert F.

    2016-01-01

    Violation of the posterior femoral cortex, commonly referred to as posterior wall blowout, can be a devastating intraoperative complication in anterior cruciate ligament (ACL) reconstruction and lead to loss of graft fixation or early graft failure. If cortical blowout occurs despite careful planning and adherence to proper surgical technique, a thorough knowledge of the anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes. This article highlights anatomic considerations for femoral tunnel placement in ACL reconstruction and techniques for avoidance and salvage of a posterior wall blowout. PMID:27335885

  16. The Simultaneous Modeling Technique: closing gaps in posteriors.

    PubMed

    Scolavino, Salvatore; Paolone, Gaetano; Orsini, Giovanna; Devoto, Walter; Putignano, Angelo

    2016-01-01

    Direct posterior restorations represent a widespread procedure in daily practice. Occlusal layering is often considered a complex task, generally not predictable and often requiring several occlusal adjustments. Moreover, direct posterior restorations are time consuming, as many small increments must be applied and cured individually to control shrinkage stress. Several authors have proposed different material layering techniques for posteriors. The authors of this article propose a simplified approach, which primarily aims to help the clinician perform quick, simple, predictable, and natural-looking occlusal modeling, reducing the need for occlusal adjustments. PMID:26835524

  17. Reversible digital images

    NASA Astrophysics Data System (ADS)

    Knox, Keith T.

    1999-04-01

    A method has been developed to hide one image inside another with little loss in image quality. If the second image is a logo or watermark, then this method may be used to protect the ownership rights of the first image and to guarantee the authenticity of the image. The two images to be combined may be either black & white or color continuous tone images. A reversible image is created by incorporating the first image in the upper 4 bits and the second image in the lower 4 bits. When viewed normally, the reversible image appears to be the first image. To view the hidden image, the bits of the combined image are reversed, exchanging all of the lower and higher order bits. When viewed in the reversed mode, the image appears to be the second or hidden image. To maintain a high level of image quality for both images, two simultaneous error diffusion calculations are run to ensure that both views of the reversible image have the same visual appearance as the originals. Any alteration of one of the images locally destroys the other image at the site of the alterations. This provides a method to detect alterations of the original image.

  18. Reversible collisionless magnetic reconnection

    SciTech Connect

    Ishizawa, A.; Watanabe, T.-H.

    2013-10-15

    Reversible magnetic reconnection is demonstrated for the first time by means of gyrokinetic numerical simulations of a collisionless magnetized plasma. Growth of a current-driven instability in a sheared magnetic field is accompanied by magnetic reconnection due to electron inertia effects. Following the instability growth, the collisionless reconnection is accelerated with development of a cross-shaped structure of current density, and then all field lines are reconnected. The fully reconnected state is followed by the secondary reconnection resulting in a weakly turbulent state. A time-reversed simulation starting from the turbulent state manifests that the collisionless reconnection process proceeds inversely leading to the initial state. During the reversed reconnection, the kinetic energy is reconverted into the original magnetic field energy. In order to understand the stability of reversed process, an external perturbation is added to the fully reconnected state, and it is found that the accelerated reconnection is reversible when the deviation of the E × B streamlines due to the perturbation is comparable with or smaller than a current layer width.

  19. Current management of posterior wall fractures of the acetabulum.

    PubMed

    Moed, Berton R; Kregor, Philip J; Reilly, Mark C; Stover, Michael D; Vrahas, Mark S

    2015-01-01

    The general goals for treating an acetabular fracture are to restore congruity and stability of the hip joint. These goals are no different from those for the subset of fractures of the posterior wall. Nevertheless, posterior wall fractures present unique problems compared with other types of acetabular fractures. Successful treatment of these fractures depends on a multitude of factors. The physician must understand their distinctive radiologic features, in conjunction with patient factors, to determine the appropriate treatment. By knowing the important points of posterior surgical approaches to the hip, particularly the posterior wall, specific techniques can be used for fracture reduction and fixation in these often challenging fractures. In addition, it is important to develop a complete grasp of potential complications and their treatment. The evaluation and treatment protocols initially developed by Letournel and Judet continue to be important; however, the surgeon also should be aware of new information published and presented in the past decade.

  20. A rare case of traumatic posterior phacocele with retinal detachment

    PubMed Central

    Sindal, Manavi D; Mourya, Deepesh

    2016-01-01

    Dislocation of crystalline lens into the anterior subconjunctival or subtenon's space is a rare but known complication of blunt trauma. Dislocation into the posterior subtenon's space is even rarer and can be associated with a complication such as occult scleral tear and retinal detachment. We report a case of traumatic posterior subtenon's dislocation of crystalline lens after blunt trauma and its successful surgical management. PMID:26953031

  1. Posterior partially edentulous jaws, planning a rehabilitation with dental implants

    PubMed Central

    Monteiro, Douglas R; Silva, Emily V F; Pellizzer, Eduardo P; Filho, Osvaldo Magro; Goiato, Marcelo C

    2015-01-01

    AIM: To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning. PMID:25610852

  2. Double bundle posterior cruciate ligament reconstruction: surgical technique and results.

    PubMed

    Fanelli, Gregory C; Beck, John D; Edson, Craig J

    2010-12-01

    The keys to successful posterior cruciate ligament reconstruction are to identify and treat all pathology, use strong graft material, accurately place tunnels in anatomic insertion sites, minimize graft bending, use a mechanical graft tensioning device, use primary and back-up graft fixation, and use the appropriate postoperative rehabilitation program. Adherence to these technical principles results in successful single and double-bundle arthroscopic transtibial tunnel posterior cruciate ligament reconstruction based upon stress radiography, arthrometer, knee ligament rating scales, and patient satisfaction measurements.

  3. Cementoblastoma of posterior maxilla involving the maxillary sinus

    PubMed Central

    Dadhich, Anuj S.; Nilesh, Kumar

    2015-01-01

    Cementoblastoma is a rare neoplasm, representing <1% of all odontogenic tumors. It usually occurs in the posterior mandible and is associated with roots of a mandibular first molar or second premolar. This paper presents a rare case of cementoblastoma in the maxillary posterior region involving the maxillary sinus, in a young female patient. The clinical, radiological, and histopathological features of the lesion are discussed along with a review of previously reported cases in the literature. PMID:26389052

  4. Erupted complex odontoma of the posterior maxilla: A rarity

    PubMed Central

    Verma, Sonika; Arul, A. Sri Kennath J.; Arul, A. Sri Sennath J.; Chitra, S.

    2015-01-01

    Complex odontomas, hamartomas of aborted tooth development, mainly occur in posterior part of the mandible and rarely erupt into the oral cavity. The spontaneous eruption may be associated with pain, inflammation of adjacent soft tissues or recurrent infection. The present case of complex odontoma is of particular interest due to its apparent eruption in the maxillary posterior segment, its association with agenesis of the second molar and impacted third molar; with the lesion being completely asymptomatic. PMID:26604611

  5. Erupted complex odontoma of the posterior maxilla: A rarity.

    PubMed

    Verma, Sonika; Arul, A Sri Kennath J; Arul, A Sri Sennath J; Chitra, S

    2015-08-01

    Complex odontomas, hamartomas of aborted tooth development, mainly occur in posterior part of the mandible and rarely erupt into the oral cavity. The spontaneous eruption may be associated with pain, inflammation of adjacent soft tissues or recurrent infection. The present case of complex odontoma is of particular interest due to its apparent eruption in the maxillary posterior segment, its association with agenesis of the second molar and impacted third molar; with the lesion being completely asymptomatic.

  6. Jerky dystonic shoulder following infarction of the posterior thalamus.

    PubMed

    Walker, Ruth H

    2015-01-01

    The syndrome of the jerky dystonic hand is recognized as a consequence of infarction of the posterior thalamus. A patient with multiple risk factors for stroke developed jerky dystonia of more proximal involvement, affecting the shoulder and speech, several months after a stroke affecting the posterior thalamic region. The cause for the proximal, rather than distal, upper limb involvement, is unclear, and is not apparent from the distribution of the lesion on neuroimaging. Injections of botulinum toxin significantly improved the symptoms.

  7. Parascapular mass revealing primary tuberculosis of the posterior arch

    PubMed Central

    Arbault, Anais; Ornetti, Paul; Chevallier, Olivier; Avril, Julien; Pottecher, Pierre

    2016-01-01

    We report the case of a parascapular abscess revealing primary tuberculosis of the posterior arch in a 31-year-old man. Sectional imaging is essential in order to detect the different lesions of this atypical spinal tuberculosis as osteolysis of the posterior arch extendible to vertebral body, osteocondensation, epidural extension which is common in this location, and high specificity of a zygapophysial, costo-vertebral or transverse arthritis.

  8. Mature posterior fossa teratoma mimicking infratentorial meningioma: a case report.

    PubMed

    Coulibaly, O; El Kacemi, I; Fatemi, N; Gana, R; Saïdi, A; Maaqili, R; Jiddane, M; Bellakhdar, F

    2012-02-01

    Intracranial teratomas are congenital neoplasms mostly diagnosed in the pediatric hood and usually involve supratentorial midline structures. These teratomas, especially those involving the posterior fossa are an uncommon and representing less than 0.5% of all intracranial tumors. We report a case of mature posterior fossa teratoma in an adult patient diagnosed in the 4th decade of life. This lesion was taken for a huge infratentorial meningioma.

  9. Optimizing tooth form with direct posterior composite restorations

    PubMed Central

    Raghu, Ramya; Srinivasan, Raghu

    2011-01-01

    Advances in material sciences and technology have provided today's clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on “direct posterior composite contacts.” The keywords used were “contacts and contours of posterior composites.” The reference list of each article was manually checked for additional articles of relevance. PMID:22144797

  10. Optimizing tooth form with direct posterior composite restorations.

    PubMed

    Raghu, Ramya; Srinivasan, Raghu

    2011-10-01

    Advances in material sciences and technology have provided today's clinicians the strategies to transform the mechanistic approach of operative dentistry into a biologic philosophy. In the last three decades, composite resins have gone from being just an esthetically pleasing way of restoring Class III and Class IV cavities to become the universal material for both anterior and posterior situations as they closely mimic the natural esthetics while restoring the form of the human dentition. In order to enhance their success, clinicians have to rethink their protocol instead of applying the same restorative concepts and principles practiced with metallic restorations. Paralleling the evolution of posterior composite resin materials, cavity designs, restorative techniques and armamentarium have also developed rapidly to successfully employ composite resins in Class II situations. Most of the earlier problems with posterior composites such as poor wear resistance, polymerization shrinkage, postoperative sensitivity, predictable bonding to dentin, etc., have been overcome to a major extent. However, the clinically relevant aspect of achieving tight contacts in Class II situations has challenged clinicians the most. This paper reviews the evolution of techniques and recent developments in achieving predictable contacts with posterior composites. A Medline search was performed for articles on "direct posterior composite contacts." The keywords used were "contacts and contours of posterior composites." The reference list of each article was manually checked for additional articles of relevance.

  11. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  12. One step arthroscopically assisted Latarjet and posterior bone-block, for recurrent posterior instability and anterior traumatic dislocation.

    PubMed

    D'Ambrosi, Riccardo; Perfetti, Carlo; Garavaglia, Guido; Taverna, Ettore

    2015-01-01

    This case presents the challenges of the surgical management for a patient with a history of recurrent posterior shoulder instability and subsequently traumatic anterior dislocation. The patient was already on the waiting list for an arthroscopic posterior stabilization with anchors, when a car accident caused an additional anterior shoulder dislocation. This traumatic anterior dislocation created a bone loss with a glenoid fracture and aggravated the preexisting posterior instability. In order to address both problems, we decided to perform an arthroscopically assisted Latarjet procedure for anterior instability and to stabilize with a bone graft for posterior instability. To our best knowledge, this type of surgical procedure has so far never been reported in the literature. The purpose of this report is to present the surgical technique and to outline the decision making process.

  13. One step arthroscopically assisted Latarjet and posterior bone-block, for recurrent posterior instability and anterior traumatic dislocation

    PubMed Central

    D’Ambrosi, Riccardo; Perfetti, Carlo; Garavaglia, Guido; Taverna, Ettore

    2015-01-01

    This case presents the challenges of the surgical management for a patient with a history of recurrent posterior shoulder instability and subsequently traumatic anterior dislocation. The patient was already on the waiting list for an arthroscopic posterior stabilization with anchors, when a car accident caused an additional anterior shoulder dislocation. This traumatic anterior dislocation created a bone loss with a glenoid fracture and aggravated the preexisting posterior instability. In order to address both problems, we decided to perform an arthroscopically assisted Latarjet procedure for anterior instability and to stabilize with a bone graft for posterior instability. To our best knowledge, this type of surgical procedure has so far never been reported in the literature. The purpose of this report is to present the surgical technique and to outline the decision making process. PMID:26288539

  14. Recovery of Third Nerve Palsy after Endovascular Packing of Internal Carotid-Posterior Communicating Artery Aneurysms

    PubMed Central

    Mavilio, N.; Pisani, R.; Rivano, C.; Testa, V.; Spaziante, R.; Rosa, M.

    2000-01-01

    Summary Endovascular packing of intracranial aneurysm with preservation of the parent vessel has become in many cases a valid alternative to surgical clipping. Regression of oculomotor disorders after clipping of internal carotid-posterior communicating artery (ICA-PCoA) aneurysms has been well assessed. This report focuses on the reversal of third nerve palsy after endovascular packing of ICA-PCoA aneurysms. To this end, clinical appearances, neuroradiological features, and endovascular interventional procedures of six treated patient are reported and discussed in the light of the very few previous case observations found in the literature. Results indicate that endovascular packing of ICA-PCoA aneurysms may produce effective recovery of correlated third nerve dysfunction. PMID:20667199

  15. Reversible Chemochromic Hydrogen Detectors

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Florida Solar Energy Center (FSEC), affiliated with the University of Central Florida, has invented a reversible pigment that changes from light beige to blue when exposed to hydrogen and back to light beige when exposed to atmospheric oxygen. In laboratory and environmental studies, the FSEC pigment in its tape form failed to change color adequately when exposed to hydrogen after one day of exposure at Kennedy Space Center's Beach Corrosion Test Facility. The reversible hydrogen-detecting tape also lost its ability to change color after being placed in an environmental chamber at 45 C for one day. The first attempts at extruding the reversible pigment into various polymers were unsuccessful because of the pigment's poor thermal stability. The goal of this project was to formulate a pigment with improved thermal and environmental stability for extrusion into a variety of appropriate polymer matrices. The formulation of the reversible hydrogen-detecting pigment was modified by removing one reagent and chemically modifying the hydrogen sensitive ingredient. This was intended to improve the hydrophobicity of the pigment and alter the thermal degradation mechanism.

  16. Reversing Discrimination: A Perspective

    ERIC Educational Resources Information Center

    Pati, Gopal; Reilly, Charles W.

    1977-01-01

    Examines the debate over affirmative action and reverse discrimination, and discusses how and why the present dilemma has developed. Suggests that organizations can best address the problem through an honest, in-depth analysis of their organizational structure and management practices. (JG)

  17. Reverse Coherent Information

    NASA Astrophysics Data System (ADS)

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2009-04-01

    We define a family of entanglement distribution protocols assisted by classical feedback communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This protocol family leads to the definition of a new entanglement distribution capacity that exceeds the unassisted entanglement distribution capacity for some interesting channels.

  18. Reverse Coherent Information

    NASA Astrophysics Data System (ADS)

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2009-05-01

    In this Letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This leads to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

  19. Time reversal communication system

    DOEpatents

    Candy, James V.; Meyer, Alan W.

    2008-12-02

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  20. Reversing Underachievement through Enrichment.

    ERIC Educational Resources Information Center

    Renzulli, Joseph S.; Baum, Susan M.; Hebert, Thomas; McCluskey, Ken W.

    1999-01-01

    Discusses problems of underachievement, especially among potentially high ability students, and the difficulties inherent in reversing this process. Presents new perspective and strategies that promote success. Describes Type III enrichment experiences as a means to unleash students' potential. Speculates as to what causes turnaround within an…

  1. Reverse coherent information.

    PubMed

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H

    2009-05-29

    In this Letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This leads to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

  2. Justice and Reverse Discrimination

    ERIC Educational Resources Information Center

    Strike, Kenneth A.

    1976-01-01

    Although this article does not necessarily recommend policies of reverse discrimination, arguments indicating that such policies are not contradictory to accepted concepts of justice are presented. The necessity of dispersing any consequent injury to society as a whole rather than to individuals is stressed. (RW)

  3. Posterior Surgery Alone in the Treatment of Post-traumatic Kyphosis by Posterior Column Osteotomy, Spondylodesis, Instrumentation, and Vertebroplasty

    PubMed Central

    Hasankhani, Ebrahim Ghayem; Ebrahimzadeh, Mohamed Hosein; Kachooei, Amir Reza; Heidari, Hosein

    2013-01-01

    Study Design Retrospective study. Purpose To determine if posterior surgery alone can satisfactorily treat post-traumatic kyphosis (PTK). Overview of Literature One of the worst complications of vertebral fractures is PTK. The type of surgery and approach to treat a symptomatic and refractory PTK is a challenging issue in spinal surgery, and yet, there is no specific treatment algorithm. Methods From August 2003 to September 2010, we collected 26 cases (male to female ratio, 2.25; mean age, 31.9±9.7 years and follow-up period of 42.4±8.1 months) with PTK treated by posterior column osteotomy, spondylodesis, instrumentation and cement vertebroplasty in one stage posterior surgery. PTK angle, Oswestry Disability Index (ODI), visual analogue scale (VAS), and subjective satisfaction from surgery were used to determine the results. We used a student t test for analyzing the data before and after surgery. Results In our patients, T11 and L1 had the highest incidence of vertebral fractures. The results indicated that in PTK, ODI, and VAS were significantly improved this surgery. Solid fusion occurred in 96.2% of patients with 3.2°±2.1° loss of correction. A total of 84.6% of patients have satisfaction level of excellent and good. Conclusions Posterior surgery alone with posterior column osteotomy, vertebroplasty, posterior spinal fusion and instrumentation can effectively treat symptomatic PTK. PMID:24353841

  4. One-stage posterior approach and combined interbody and posterior fusion for thoracolumbar spinal tuberculosis with kyphosis in children.

    PubMed

    Zhang, Hong-Qi; Wang, Yu-Xiang; Guo, Chao-Feng; Liu, Jin-Yang; Wu, Jian-Huang; Chen, Jing; Guo, Dai; Tang, Ming-Xing

    2010-11-02

    The goal of this study was to determine the efficacy and feasibility of surgical management of advanced thoracolumbar spine tuberculosis with kyphosis in children in poor general condition with 1-stage posterior decompression, interbody grafts, and posterior instrumentation and fusion. Between 2006 and 2008, 7 children with advanced thoracolumbar spinal tuberculosis accompanied by kyphosis and in poor general condition were treated with 1-stage posterior decompression, interbody grafts, and posterior instrumentation and fusion followed by chemotherapy. Mean follow-up was 34 months (range, 27-42 months). Patients were evaluated pre- and postoperatively for erythrocyte sedimentation rate (ESR), neurological status, pain, spinal canal compromise, and kyphotic angle. Spinal tuberculosis was completely cured and the grafted bones fused in all 7 patients. There was no recurrence of the disease in any patient at final follow-up. In all patients, ESR was normal within 3 months, Frankel neurological classification improved, and pain relief was obtained. Average canal compromise was 52.57% (range, 35%-75%) preoperatively and 9.86% (range, 0%-19%) postoperatively. Average preoperative kyphosis was 37.9°, which decreased to 5.4° postoperatively. There was no significant loss of correction at last follow-up. Our results show that 1-stage posterior decompression, interbody grafts, and posterior instrumentation and fusion followed by chemotherapy is an alternative treatment for children with advanced thoracolumbar spinal tuberculosis and in poor general condition.

  5. Correction of dental Class III with posterior open bite by simple biomechanics using an anterior C-tube miniplate

    PubMed Central

    Ahn, Hyo-Won; Chung, Kyu-Rhim; Kang, Suk-Man; Lin, Lu; Nelson, Gerald

    2012-01-01

    In the correction of dental Class III molar relationship in skeletal Class II patients, uprighting of the mandibular posterior segments without opening the mandible is an important treatment objective. In the case reported herein, a C-tube miniplate fixed to the lower labial symphysis and connected with a nickel-titanium reverse-curved archwire provided effective uprighting of the lower molars, without the need of orthodontic appliances on the mandibular anteriors. Using this approach, an appropriate magnitude of force is exerted on the molars while avoiding any negative effect on the mandibular anteriors. PMID:23173121

  6. Posterior Corneal Characteristics of Cataract Patients with High Myopia

    PubMed Central

    Jing, Qinghe; Tang, Yating; Qian, Dongjin; Lu, Yi; Jiang, Yongxiang

    2016-01-01

    Purpose To evaluate the characteristics of the posterior corneal surface in patients with high myopia before cataract surgery. Methods We performed a cross-sectional study at the Eye and ENT Hospital of Fudan University, Shanghai, China. Corneal astigmatism and axial length were measured with a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in a high-myopia study group of 167 eyes (axial length ≥ 26 mm) and a control group of 150 eyes (axial length > 20 mm and < 25 mm). Results Total corneal astigmatism and anterior corneal astigmatism values were higher in the high-myopia group than in the control group. There was no significant difference in posterior corneal astigmatism between the high-myopia study group and the control group. In the study group, the mean posterior corneal astigmatism (range 0 – −0.9 diopters) was –0.29 diopters (D) ± 0.17 standard deviations (SD). The steep corneal meridian was aligned vertically (60°–120°) in 87.43% of eyes for the posterior corneal surface, and did not change with increasing age. There was a significant correlation (r = 0.235, p = 0.002) between posterior corneal astigmatism and anterior corneal astigmatism, especially when the anterior corneal surface showed with-the-rule (WTR) astigmatism (r = 0.452, p = 0.000). There was a weak negative correlation between posterior corneal astigmatism and age (r = –0.15, p = 0.053) in the high-myopia group. Compared with total corneal astigmatism values, the anterior corneal measurements alone overestimated WTR astigmatism by a mean of 0.27 ± 0.18 D in 68.75% of eyes, underestimated against-the-rule (ATR) astigmatism by a mean of 0.41 ± 0.28 D in 88.89% of eyes, and underestimated oblique astigmatism by a mean of 0.24 ± 0.13 D in 63.64% of eyes. Conclusions Posterior corneal astigmatism decreased with age and remained as ATR astigmatism in most cases of high myopia. There was a significant correlation between posterior corneal

  7. The enigmatic diagnosis of posterior tibialis tendon rupture.

    PubMed Central

    Marcus, R. E.; Pfister, M. E.

    1993-01-01

    Posterior tibialis tendon rupture is a diagnosis that is often missed. This is thought to be secondary to nonspecific clinical findings and the lack of any laboratory or radiographic test to reliably confirm the diagnosis. We report sixteen cases of surgically confirmed posterior tibialis tendon rupture. Based on our review of these patients, the diagnosis of posterior tibialis tendon rupture should be strongly suspected in the adult patient presenting with a history of a twisting ankle injury and generalized medial ankle pain and swelling. A flexible, asymmetric pes planus and forefoot pronation deformity with absence of posterior tibialis tendon function on manual testing is seen on examination. This is associated with loss of ipsilateral heel inversion on bilateral heel rise. The patient is usually unable to perform ipsilateral single leg heel rise and has less severe pes planus of the contralateral foot. This study reviews the presentation, pathophysiology, diagnosis, and treatment of posterior tibialis tendon rupture. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:7820739

  8. Flexor Digitorum Accessorius Longus: Importance of Posterior Ankle Endoscopy.

    PubMed

    Batista, Jorge Pablo; Del Vecchio, Jorge Javier; Golanó, Pau; Vega, Jordi

    2015-01-01

    Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL) travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL) described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion. PMID:26060592

  9. Flexor Digitorum Accessorius Longus: Importance of Posterior Ankle Endoscopy

    PubMed Central

    Batista, Jorge Pablo; del Vecchio, Jorge Javier; Golanó, Pau; Vega, Jordi

    2015-01-01

    Endoscopy for the posterior region of the ankle through two portals is becoming more widespread for the treatment of a large number of conditions which used to be treated with open surgery years ago. The tendon of the flexor hallucis longus (FHL) travels along an osteofibrous tunnel between the posterolateral and posteromedial tubercles of the talus. Chronic inflammation of this tendon may lead to painful stenosing tenosynovitis. The aim of this report is to describe two cases depicting an accessory tendon which is an anatomical variation of the flexor hallucis longus in patients with posterior friction syndrome due to posterior ankle impingement and associated with a posteromedial osteochondral lesion of the talus. The anatomical variation (FDAL) described was a finding during an endoscopy of the posterior region of the ankle, and we have spared it by sectioning the superior flexor retinaculum only. The accessory flexor digitorum longus is an anatomical variation and should be taken into account when performing an arthroscopy of the posterior region of the ankle. We recommend this treatment on this type of injury although we admit this does not make a definite conclusion. PMID:26060592

  10. Endovascular solutions to arterial injury due to posterior spine surgery.

    PubMed

    Loh, Shang A; Maldonaldo, Thomas S; Rockman, Caron B; Lamparello, Patrick J; Adelman, Mark A; Kalhorn, Stephen P; Frempong-Boadu, Anthony; Veith, Frank J; Cayne, Neal S

    2012-05-01

    Iatrogenic arterial injury is an uncommon but recognized complication of posterior spinal surgery. The spectrum of injuries includes vessel perforation leading to hemorrhage, delayed pseudoaneurysm formation, and threatened perforation by screw impingement on arterial vessels. Repair of these injuries traditionally involved open direct vessel repair or graft placement, which can be associated with significant morbidity. We identified five patients with iatrogenic arterial injury during or after posterior spinal surgery between July 2004 and August 2009 and describe their endovascular treatment. Intraoperative arterial bleeding was encountered in two patients during posterior spinal surgery. The posterior wounds were packed, temporarily closed, and the patient was placed supine. In both patients, angiography demonstrated arterial injury necessitating repair. Covered stent grafts were deployed through femoral cutdowns to exclude the areas of injury. In three additional patients, postoperative computed tomography imaging demonstrated pedicle screws abutting/penetrating the thoracic or abdominal aorta. Angiography or intravascular ultrasound imaging, or both, confirmed indention/perforation of the aorta by the screw. Aortic stent graft cuffs were deployed through femoral cutdowns to cover the area of aortic contact before hardware removal. All five patients did well and were discharged home in good condition. Endovascular repair of arterial injuries occurring during posterior spinal procedures is feasible and can offer a safe and less invasive alternative to open repair.

  11. External Dacryocystorhinostomy with and Without Suturing the Posterior Mucosal Flaps

    PubMed Central

    Kaçaniku, Gazmend; Begolli, Ilir

    2014-01-01

    ABSTRACT Purpose: To evaluate the outcome of the external dacryocystorhinostomy with and without suturing the posterior mucosal flaps. Methods: This study included 106 patients with lacrimal drainage system disorders who underwent the external dacryocystorhinostomy. Fifty four patients (Group A) underwent external dacryocystorhinostomy with suturing anterior and posterior flaps of the lacrimal sac and nasal mucosa, and the results obtained were compared with those of another series of 52 patients (Group B) where dacryocystorhinostomy was performed with suturing only the anterior flaps, whereas posterior mucosal flaps were excised. Results: The success rate was evaluated by lacrimal patency to irrigation and relief of epiphora. Patency achieved in groups A and B was 94.4% and 96.2%, respectively. There was no statistically significant difference in success rate between the groups. Conclusion: Our study suggests that external dacryocystorhinostomy with suturing anterior and posterior flaps have no advantage over dacryocystorhinostomy with suturing only anterior flaps. Anastomosis by suturing only anterior flaps and excision of the posterior flaps is easier to perform and may improve the success rate of external dacryocystorhinostomy. PMID:24783915

  12. Features extraction in anterior and posterior cruciate ligaments analysis.

    PubMed

    Zarychta, P

    2015-12-01

    The main aim of this research is finding the feature vectors of the anterior and posterior cruciate ligaments (ACL and PCL). These feature vectors have to clearly define the ligaments structure and make it easier to diagnose them. Extraction of feature vectors is obtained by analysis of both anterior and posterior cruciate ligaments. This procedure is performed after the extraction process of both ligaments. In the first stage in order to reduce the area of analysis a region of interest including cruciate ligaments (CL) is outlined in order to reduce the area of analysis. In this case, the fuzzy C-means algorithm with median modification helping to reduce blurred edges has been implemented. After finding the region of interest (ROI), the fuzzy connectedness procedure is performed. This procedure permits to extract the anterior and posterior cruciate ligament structures. In the last stage, on the basis of the extracted anterior and posterior cruciate ligament structures, 3-dimensional models of the anterior and posterior cruciate ligament are built and the feature vectors created. This methodology has been implemented in MATLAB and tested on clinical T1-weighted magnetic resonance imaging (MRI) slices of the knee joint. The 3D display is based on the Visualization Toolkit (VTK).

  13. Gridded electron reversal ionizer

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor)

    1993-01-01

    A gridded electron reversal ionizer forms a three dimensional cloud of zero or near-zero energy electrons in a cavity within a filament structure surrounding a central electrode having holes through which the sample gas, at reduced pressure, enters an elongated reversal volume. The resultant negative ion stream is applied to a mass analyzer. The reduced electron and ion space-charge limitations of this configuration enhances detection sensitivity for material to be detected by electron attachment, such as narcotic and explosive vapors. Positive ions may be generated by generating electrons having a higher energy, sufficient to ionize the target gas and pulsing the grid negative to stop the electron flow and pulsing the extraction aperture positive to draw out the positive ions.

  14. Reversed field pinch diagnostics

    SciTech Connect

    Weber, P.G.

    1986-01-01

    The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP.

  15. Reverse genetics of mononegavirales.

    PubMed

    Conzelmann, K K

    2004-01-01

    "Reverse genetics" or de novo synthesis of nonsegmented negative-sense RNA viruses (Mononegavirales) from cloned cDNA has become a reliable technique to study this group of medically important viruses. Since the first generation of a negative-sense RNA virus entirely from cDNA in 1994, reverse genetics systems have been established for members of most genera of the Rhabdo-, Paramyxo-, and Filoviridae families. These systems are based on intracellular transcription of viral full-length RNAs and simultaneous expression of viral proteins required to form the typical viral ribonucleoprotein complex (RNP). These systems are powerful tools to study all aspects of the virus life cycle as well as the roles of virus proteins in virus-host interplay and pathogenicity. In addition, recombinant viruses can be designed to have specific properties that make them attractive as biotechnological tools and live vaccines. PMID:15298166

  16. Reversible watermarking for images

    NASA Astrophysics Data System (ADS)

    van Leest, Arno J.; van der Veen, Michiel; Bruekers, Fons

    2004-06-01

    Reversible watermarking is a technique for embedding data in a digital host signal in such a manner that the original host signal can be restored in a bit-exact manner in the restoration process. In this paper, we present a general framework for reversible watermarking in multi-media signals. A mapping function, which is in general neither injective nor surjective, is used to map the input signal to a perceptually equivalent output signal. The resulting unused sample values of the output signal are used to encode additional (watermark) information and restoration data. At the 2003 SPIE conference, examples of this technique applied to digital audio were presented. In this paper we concentrate on color and gray-scale images. A particular challenge in this context is not only the optimization of rate-distortion, but also the measure of perceptual quality (i.e. the distortion). In literature distortion is often expressed in terms of PSNR, making comparison among different techniques relatively straightforward. We show that our general framework for reversible watermarking applies to digital images and that results can be presented in terms of PSNR rate-distortions. However, the framework allows for more subtle signal manipulations that are not easily expressed in terms of PSNR distortion. These changes involve manipulations of contrast and/or saturation.

  17. Reversible DNA compaction.

    PubMed

    González-Pérez, Alfredo

    2014-01-01

    In this review we summarize and discuss the different methods we can use to achieve reversible DNA compaction in vitro. Reversible DNA compaction is a natural process that occurs in living cells and viruses. As a result these process long sequences of DNA can be concentrated in a small volume (compacted) to be decompacted only when the information carried by the DNA is needed. In the current work we review the main artificial compacting agents looking at their suitability for decompaction. The different approaches used for decompaction are strongly influenced by the nature of the compacting agent that determines the mechanism of compaction. We focus our discussion on two main artificial compacting agents: multivalent cations and cationic surfactants that are the best known compacting agents. The reversibility of the process can be achieved by adding chemicals like divalent cations, alcohols, anionic surfactants, cyclodextrins or by changing the chemical nature of the compacting agents via pH modifications, light induced conformation changes or by redox-reactions. We stress the relevance of electrostatic interactions and self-assembly as a main approach in order to tune up the DNA conformation in order to create an on-off switch allowing a transition between coil and compact states. The recent advances to control DNA conformation in vitro, by means of molecular self-assembly, result in a better understanding of the fundamental aspects involved in the DNA behavior in vivo and serve of invaluable inspiration for the development of potential biomedical applications. PMID:24444152

  18. Rupture of Posterior Cruciate Ligament: Diagnosis and Treatment Principles

    PubMed Central

    Nam, Shin Woo

    2011-01-01

    Posterior cruciate ligament (PCL) injuries associated with multiple ligament injuries can be easily diagnosed, but isolated PCL tears are less symptomatic, very difficult to diagnose, and frequently misdiagnosed. If a detailed investigation of the history of illness suggests a PCL injury, careful physical examinations including the posterior drawer test, dial test, varus and valgus test should be done especially if the patient complains of severe posterior knee pain in >90° of flexion. Vascular assessment and treatment should be done to avoid critical complications. An individualized treatment plan should be established after consideration of the type of tear, time after injury, associated collateral ligament injuries, bony alignment, and status of remnant. The rehabilitation should be carried out slower than that after anterior cruciate ligament reconstruction. PMID:22570824

  19. ‘Split posterior tooth’: conservative clinical re-attachment

    PubMed Central

    Abraham, Sathish; Chacko, Lisa Neelathil

    2014-01-01

    Trauma is the prime causative factor for fracture of teeth/dentition. Many procedural management options are followed successfully in relation to the anterior teeth. However, most posterior cases where the tooth is fractured have only limited options to pursue to save the tooth. Fractured teeth, whether they are vital/non-vital, are predominantly managed with surgical options. This paper discusses a conservative approach to reattaching a split posterior tooth. A split tooth situation is mostly an absolute indication for extraction, but the clinician may go in for extensive surgical procedures if he/she wishes to save it. The reattachment of the tooth can be successfully done and it can be put to function. This paper discusses how a split posterior tooth can be treated successfully, although depending on multiple factors. A full crown cemented after successful reattachment and root canal therapy would provide sufficient support in order for the tooth to heal. PMID:25080545

  20. 'Split posterior tooth': conservative clinical re-attachment.

    PubMed

    Abraham, Sathish; Chacko, Lisa Neelathil

    2014-07-30

    Trauma is the prime causative factor for fracture of teeth/dentition. Many procedural management options are followed successfully in relation to the anterior teeth. However, most posterior cases where the tooth is fractured have only limited options to pursue to save the tooth. Fractured teeth, whether they are vital/non-vital, are predominantly managed with surgical options. This paper discusses a conservative approach to reattaching a split posterior tooth. A split tooth situation is mostly an absolute indication for extraction, but the clinician may go in for extensive surgical procedures if he/she wishes to save it. The reattachment of the tooth can be successfully done and it can be put to function. This paper discusses how a split posterior tooth can be treated successfully, although depending on multiple factors. A full crown cemented after successful reattachment and root canal therapy would provide sufficient support in order for the tooth to heal.

  1. Rupture of posterior cruciate ligament: diagnosis and treatment principles.

    PubMed

    Lee, Beom Koo; Nam, Shin Woo

    2011-09-01

    Posterior cruciate ligament (PCL) injuries associated with multiple ligament injuries can be easily diagnosed, but isolated PCL tears are less symptomatic, very difficult to diagnose, and frequently misdiagnosed. If a detailed investigation of the history of illness suggests a PCL injury, careful physical examinations including the posterior drawer test, dial test, varus and valgus test should be done especially if the patient complains of severe posterior knee pain in >90° of flexion. Vascular assessment and treatment should be done to avoid critical complications. An individualized treatment plan should be established after consideration of the type of tear, time after injury, associated collateral ligament injuries, bony alignment, and status of remnant. The rehabilitation should be carried out slower than that after anterior cruciate ligament reconstruction.

  2. Quantification of Posterior Globe Flattening: Methodology Development and Validation

    NASA Technical Reports Server (NTRS)

    Lumpkins, Sarah B.; Garcia, Kathleen M.; Sargsyan, Ashot E.; Hamilton, Douglas R.; Berggren, Michael D.; Ebert, Douglas

    2012-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in the eyes of several astronauts. This phenomenon is known to affect some terrestrial patient populations and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT) or B-mode Ultrasound (US), without consistent objective criteria. NASA uses a semiquantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was ot initiate development of an objective quantification methodology to monitor small changes in posterior globe flattening.

  3. Quantification of Posterior Globe Flattening: Methodology Development and Validationc

    NASA Technical Reports Server (NTRS)

    Lumpkins, S. B.; Garcia, K. M.; Sargsyan, A. E.; Hamilton, D. R.; Berggren, M. D.; Antonsen, E.; Ebert, D.

    2011-01-01

    Microgravity exposure affects visual acuity in a subset of astronauts, and mechanisms may include structural changes in the posterior globe and orbit. Particularly, posterior globe flattening has been implicated in several astronauts. This phenomenon is known to affect some terrestrial patient populations, and has been shown to be associated with intracranial hypertension. It is commonly assessed by magnetic resonance imaging (MRI), computed tomography (CT), or B-mode ultrasound (US), without consistent objective criteria. NASA uses a semi-quantitative scale of 0-3 as part of eye/orbit MRI and US analysis for occupational monitoring purposes. The goal of this study was to initiate development of an objective quantification methodology for posterior globe flattening.

  4. [Esthetic restoration of the posterior sector. State of the art].

    PubMed

    Prati, C; Tiozzi, E; Giommoni, E

    Patient's aesthetic requirements have increased in the past few years. The limited resistance of composites to wear has delayed their universal adoption for restoration of Class I and II cavity preparations in adult teeth. Although the potential use for posterior composite resin appears promising, the point at which such materials may be regarded as ideal, reliable, routine alternatives to silver amalgam has not been reached for materials of previous generation. To resolve some of the problems associated with the posterior composite resin, new materials (photo-cured GIC, multi step bonding agent, improved composite resins as P-50, Heliomolar Radiopaque, Ray Post) and new techniques have been introduced. In this paper the problems and questions raised with the use of posterior composites have been discussed.

  5. Cavernous hemangioma of the posterior mediastinum with bony invasion.

    PubMed

    Yun, Takamasa; Suzuki, Hidemi; Tagawa, Tetsuzo; Iwata, Takekazu; Mizobuchi, Teruaki; Yoshida, Shigetoshi; Yamazaki, Masashi; Yoshino, Ichiro

    2016-01-01

    We herein report a case of a cavernous hemangioma of the posterior mediastinum treated with surgical resection. Mediastinal hemangiomas are rare and diagnosis is difficult prior to operation. A 58-year-old female was referred to our hospital for back pain and a tumor in the left posterior mediastinum that was detected by chest computed tomography (CT). CT showed a tumor adjacent to the left side of the fifth thoracic vertebrae measuring 60 × 50 mm with invasion into and destruction of the 5th rib. The tumor was resected successfully via hemilaminectomy with costotransversectomy, and was revealed to be a cavernous hemangioma histologically. 1 year and 5 months after surgery, the patient was asymptomatic and without a recurrence. Hemangiomas are usually considered benign but sometimes behave aggressively with destruction of the neighboring structures. We consider en bloc resection to be safe and effective for aggressive cavernous hemangiomas of the posterior mediastinum.

  6. Posterior resin-based composite: review of the literature.

    PubMed

    Burgess, J O; Walker, Richard; Davidson, J M

    2002-01-01

    The use of direct posterior resin-based composite has increased primarily due to patient esthetic desires and product improvements. Other factors (substantiated or not) contributing to increased use of resin-based composite are environmental and health concerns with dental amalgam. New visible light cured resin-based composite products are introduced yearly, as manufacturers continue to improve this tooth-colored restorative material. This paper will characterize current posterior resin-based composite materials (hybrid, microfill, flowable, and packable), review recent in vitro and clinical research, and recommend indications for these materials. In addition, the literature on compomers will be reviewed and recommendation made for their use. The data indicates that composite resin is a technique sensitive restorative material that can be used in large preparations if proper manipulation and isolation can be maintained. Compomers may also be used as an esthetic posterior restorative if proper isolation is provided.

  7. Methodology for proximal wear evaluation in posterior resin composites.

    PubMed

    Ziemiecki, T L; Wendt, S L; Leinfelder, K F

    1992-08-01

    The purpose of this study was to utilize a methodology to measure proximal wear of posterior resin composites with respect to time. A group of 10 teeth (5 premolars and 5 molars) were restored with P-30, a posterior resin composite restorative. At placement the proximal contacts were judged to be closed visually, and with unwaxed dental floss. The patients were then recalled at intervals of 6, 12, and 36 months for indirect wear evaluations. Resin composite transfer copings were made and indexed on baseline models. A zoom stereomicroscope, at 20 microns resolution, was used to determine proximal wear. For the posterior restorative material the premolar and molar teeth wore at the same rate. The amount of wear was statistically greater for premolar teeth at 6 and 12-month evaluation periods than molar teeth. At 36 months, there was no statistical difference in wear between premolar and molar teeth.

  8. Rotational stability of a posterior stabilized total knee arthroplasty.

    PubMed

    Whiteside, L A; Amador, D D

    1989-05-01

    The effect of the posterior stabilizing mechanism on rotational stability in total knee arthroplasty (TKA) was investigated in six cadaver knees using a special knee-testing device. The device evaluated varus-valgus, rotational, and anteroposterior (AP) stability in the normal knee compared to a posterior stabilized TKA with either a rotationally constrained or an unconstrained articular surface. None of the stability parameters was significantly different from normal in either configuration of the tibial surface, but the constrained surface did decrease rotational deflection compared to the rotationally unconstrained surfaces. These findings show that rotational constraint in a posterior stabilized TKA is not necessary to achieve rotational stability as long as varus-valgus stability is achieved by appropriately tensioning the collateral ligaments. PMID:2706852

  9. The development of the posterior body in zebrafish.

    PubMed

    Kanki, J P; Ho, R K

    1997-02-01

    In order to understand the developmental mechanisms of posterior body formation in the zebrafish, a fate map of the zebrafish tailbud was generated along with a detailed analysis of tailbud cell movements. The fate map of the zebrafish tailbud shows that it contains tissue-restricted domains and is not a homogeneous blastema. Furthermore, time-lapse analysis shows that some cell movements and behaviors in the tailbud are similar to those seen during gastrulation, while others are unique to the posterior body. The extension of axial mesoderm and the continuation of ingression throughout zebrafish tail development suggests the continuation of processes initiated during gastrulation. Unique properties of zebrafish posterior body development include the bilateral distribution of tailbud cell progeny and the exhibition of different forms of ingression within specific tailbud domains. The ingression of cells in the anterior tailbud only gives rise to paraxial mesoderm, at the exclusion of axial mesoderm. Cells of the posterior tailbud undergo subduction, a novel form of ingression resulting in the restriction of this tailbud domain to paraxial mesodermal fates. The intermixing of spinal cord and muscle precursor cells, as well as evidence for pluripotent cells within the tailbud, suggest that complex inductive mechanisms accompany these cell movements throughout tail elongation. Rates of cell proliferation in the tailbud were examined and found to be relatively low at the tip of the tail indicating that tail elongation is not due to growth at its posterior end. However, higher rates of cell proliferation in the dorsomedial region of the tail may contribute to the preferential posterior movement of cells in this tailbud region and to the general extension of the tail. Understanding the cellular movements, cell fates and gene expression patterns in the tailbud will help to determine the nature of this important aspect of vertebrate development. PMID:9043069

  10. Superior labrum anterior to posterior tears in throwing athletes.

    PubMed

    Lintner, David M

    2013-01-01

    Superior labrum anterior to posterior (SLAP) tears and partial undersurface tears of the rotator cuff are common in experienced throwers, may be adaptive, and are only occasionally symptomatic. Pain in the shoulder of a throwing athlete with an MRI-documented SLAP tear or partial undersurface tear of the rotator cuff can be managed nonsurgically, with attention to posterior capsular contracture, scapular dyskinesia, and rotator cuff strength. The results of the surgical repair of SLAP lesions in the throwing athlete, with or without rotator cuff repair, are inferior to those of nonsurgical treatment. The cause of pain in the throwing athlete must be accurately diagnosed without reliance on MRI findings. PMID:23395053

  11. Bilambdoid and posterior sagittal synostosis: the Mercedes Benz syndrome.

    PubMed

    Moore, M H; Abbott, A H; Netherway, D J; Menard, R; Hanieh, A

    1998-09-01

    A consistent pattern of craniosynostosis in the sagittal and bilateral lambdoid sutures is described in three patients. The external cranial ridging associated with fusion of these sutures produces a characteristic triradiate, or "Mercedes Benz," appearance to the posterior skull. Locally marked growth restriction is evident in the posterior fossa with compensatory secondary expansion of the anterior fossa manifesting a degree of frontal bossing which mimics bicoronal synostosis. Although this appearance could lead to inadvertent surgery in the frontal region, attention to the occipital region with wide early suture excision and vault shaping is indicated.

  12. Direct posterior composite restorations: simplified success through a systematic approach.

    PubMed

    Koczarski, Michael J; Corredor, Adriana C

    2002-01-01

    Posterior resin-based composites have become an indispensable part of the aesthetic restorative armamentarium. The creation of a functional, anatomical contact, however, remains a challenge for many clinicians. In order to meet both aesthetic and functional demands in the posterior quadrant, a composite resin with enhanced physical and handling properties must be used. This article demonstrates a predictable technique for creating proximal contact using a resin microfill that will allow clinicians to gain confidence in their ability to provide aesthetic and functional Class II restorations.

  13. Pedicle Screw-Based Posterior Dynamic Stabilization: Literature Review

    PubMed Central

    Sengupta, Dilip K.; Herkowitz, Harry N.

    2012-01-01

    Posterior dynamic stabilization (PDS) indicates motion preservation devices that are aimed for surgical treatment of activity related mechanical low back pain. A large number of such devices have been introduced during the last 2 decades, without biomechanical design rationale, or clinical evidence of efficacy to address back pain. Implant failure is the commonest complication, which has resulted in withdrawal of some of the PDS devices from the market. In this paper the authors presented the current understanding of clinical instability of lumbar motions segment, proposed a classification, and described the clinical experience of the pedicle screw-based posterior dynamic stabilization devices. PMID:23227349

  14. Observing posterior capsule lens haptics in living postoperative eyes.

    PubMed

    Miyake, K

    1984-08-01

    The cycloscope, an aid for observing the ciliary body, was used to study lens haptic fixation in 100 living eyes (200 haptics). Although the whole aspect of the lens could be viewed in only about 20 haptics (10%), in 102 haptics (51%), judgment about whether fixation was in or out of the bag could be made based on the relationship of the visible part of the lens haptic and the surrounding tissues. Thus, the method was found to be useful in studying the fixation mechanism of posterior chamber lens haptics in living postoperative eyes. Two cases of J-loop posterior chamber lens implantation studied by cycloscopy are reported.

  15. Superior labrum anterior to posterior tears in throwing athletes.

    PubMed

    Lintner, David M

    2013-01-01

    Superior labrum anterior to posterior (SLAP) tears and partial undersurface tears of the rotator cuff are common in experienced throwers, may be adaptive, and are only occasionally symptomatic. Pain in the shoulder of a throwing athlete with an MRI-documented SLAP tear or partial undersurface tear of the rotator cuff can be managed nonsurgically, with attention to posterior capsular contracture, scapular dyskinesia, and rotator cuff strength. The results of the surgical repair of SLAP lesions in the throwing athlete, with or without rotator cuff repair, are inferior to those of nonsurgical treatment. The cause of pain in the throwing athlete must be accurately diagnosed without reliance on MRI findings.

  16. Bilambdoid and posterior sagittal synostosis: the Mercedes Benz syndrome.

    PubMed

    Moore, M H; Abbott, A H; Netherway, D J; Menard, R; Hanieh, A

    1998-09-01

    A consistent pattern of craniosynostosis in the sagittal and bilateral lambdoid sutures is described in three patients. The external cranial ridging associated with fusion of these sutures produces a characteristic triradiate, or "Mercedes Benz," appearance to the posterior skull. Locally marked growth restriction is evident in the posterior fossa with compensatory secondary expansion of the anterior fossa manifesting a degree of frontal bossing which mimics bicoronal synostosis. Although this appearance could lead to inadvertent surgery in the frontal region, attention to the occipital region with wide early suture excision and vault shaping is indicated. PMID:9780908

  17. Robotic radical prostatectomy: advantages of an initial posterior dissection.

    PubMed

    Zorn, Kevin C

    2008-09-01

    During robotic radical prostatectomy (RRP), many surgeons currently employ the modified-Montsouris technique as initially described by Menon in 2002 with initial anterior prostate dissection. The anterior approach simulates the routine retropubic technique which open surgeons feel most comfortable with. Unfortunately, we observed early on in our experience that dissection of the seminal vesicles (SV) and vas deferens (VD) through a limited sized bladder neck posed limitations on working space and anatomic differentiation. As such, we have continued using a posterior-first dissection for several specific advantages. Herein, we describe our initial posterior dissection during RRP and discuss potential advantages of this approach, particularly for novice robotic surgeons. PMID:27628248

  18. Lesion Analysis of Cortical Regions Associated with the Comprehension of Nonreversible and Reversible Yes/No Questions

    ERIC Educational Resources Information Center

    Race, David S.; Ochfeld, Elisa; Leigh, Richard; Hillis, Argye E.

    2012-01-01

    We investigated the association between yes/no sentence comprehension and dysfunction in anterior and posterior left-hemisphere cortical regions in acute stroke patients. More specifically, we manipulated whether questions were Nonreversible (e.g., Are limes sour?) or Reversible (e.g., Is a horse larger than a dog?) to investigate the regions…

  19. Affirmative Action, or Reverse Discrimination?

    ERIC Educational Resources Information Center

    Dansby, Ike

    1996-01-01

    Determines the impact of affirmative action programs in response to charges that they are policies of reverse discrimination. Reviewing affirmative action programs submitted by Michigan State departments, researchers determined no reverse discrimination was apparent based on low numbers of reverse discrimination complaints filed by whites. (GR)

  20. Reversal bending fatigue testing

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Tan, Ting

    2014-10-21

    Embodiments for apparatuses for testing reversal bending fatigue in an elongated beam are disclosed. Embodiments are configured to be coupled to first and second end portions of the beam and to apply a bending moment to the beam and create a pure bending condition in an intermediate portion of the beam. Embodiments are further configured to cyclically alternate the direction of the bending moment applied to the beam such that the intermediate portion of the beam cyclically bends in opposite directions in a pure bending condition.

  1. Posterior Cruciate Ligament Function Following Total Knee Arthroplasty

    PubMed Central

    Emodi, George J; Callaghan, John J; Pedersen, Douglas R; Brown, Thomas D

    1999-01-01

    One of the most commonly cited reasons for retaining the posterior cruciate ligament (PCL) during total knee arthroplasty is to preserve femoral rollback and theoretically improve extensor mechanism efficiency (lengthening the moment arm). This study was undertaken to assess PCL function in this regard and to delineate the effects of joint line elevation that can be manipulated intraoperatively by the surgeon. The anterior movement of tibiofemoral contact following PCL resection at flexion angles 60 degrees demonstrated the beneficial effect of the PCL on extensor function. This anterior translation and the concomitant increases in quadriceps tendon load and patellofemoral contact pressures were consistently observed. This study demonstrated that small changes of the joint line position significantly influenced PCL strain and knee kinematics. In order to preserve the desired functions that would be lost with an overly lax PCL and to avoid the potential adverse effects of an overly tight PCL (posterior edge loading and increased tibiofemoral contact), the surgeon should make every effort to restore the preoperative joint line. If this is not possible, consideration should be given to posterior cruciate recession or use of a posterior cruciate substituting design. PMID:10847521

  2. Spontaneous defects between the mastoid and posterior cranial fossa.

    PubMed

    Rereddy, Shruthi K; Mattox, Douglas E

    2016-01-01

    Conclusions Spontaneous defects between the mastoid and the posterior cranial fossa are exceedingly rare. Patients with these lesions may have a lower BMI compared to those with middle cranial fossa encephaloceles, but are otherwise demographically similar. This study recommends repair via a transtemporal approach to allow for examination of the entire posterior face of the temporal bone. Objective To describe cases of spontaneous posterior cranial fossa defects. Methods This study reviewed all cases of spontaneous posterior fossa defects presenting to a tertiary referral center over the last decade and described clinical presentation, imaging, operative findings, and outcomes. We also compared these lesions to those previously reported in the literature as well as the more common spontaneous encephaloceles of the middle cranial fossa. Results This study identified five cases with a mean age of 61.4 years, female-to-male ratio of 4:1, and a mean BMI of 31. Three cases presented with spontaneous pneumocephalus, one with CSF otorrhea, and one as an incidental imaging finding. Four defects were found medial to the sigmoid sinus and one was in the lateral retrosigmoid air cells.

  3. Posterior Cortical Atrophy Presenting with Superior Arcuate Field Defect

    PubMed Central

    Wan, Sue Ling; Bukowska, Danuta M.; Ford, Stephen; Chen, Fred K.

    2015-01-01

    An 80-year-old female with reading difficulty presented with progressive arcuate field defect despite low intraocular pressure. Over a 5-year period, the field defect evolved into an incongruous homonymous hemianopia and the repeated neuroimaging revealed progressive posterior cortical atrophy. Further neuropsychiatric assessment demonstrated symptoms and signs consistent with Benson's syndrome. PMID:26417467

  4. Suture Bridge Fixation Technique for Posterior Cruciate Ligament Avulsion Fracture.

    PubMed

    Lee, Kwang Won; Yang, Dae Suk; Lee, Gyu Sang; Choy, Won Sik

    2015-12-01

    We presented a surgical technique including a suture bridge technique with relatively small incision for the reduction and fixation of posterior ligament avulsion fractures. A suture anchor was used to hold the avulsed fragment and a knotless anchor was used to continuously compress the bony fragment into the fracture site, thereby maintaining reduction during healing.

  5. Multiclass Posterior Probability Twin SVM for Motor Imagery EEG Classification.

    PubMed

    She, Qingshan; Ma, Yuliang; Meng, Ming; Luo, Zhizeng

    2015-01-01

    Motor imagery electroencephalography is widely used in the brain-computer interface systems. Due to inherent characteristics of electroencephalography signals, accurate and real-time multiclass classification is always challenging. In order to solve this problem, a multiclass posterior probability solution for twin SVM is proposed by the ranking continuous output and pairwise coupling in this paper. First, two-class posterior probability model is constructed to approximate the posterior probability by the ranking continuous output techniques and Platt's estimating method. Secondly, a solution of multiclass probabilistic outputs for twin SVM is provided by combining every pair of class probabilities according to the method of pairwise coupling. Finally, the proposed method is compared with multiclass SVM and twin SVM via voting, and multiclass posterior probability SVM using different coupling approaches. The efficacy on the classification accuracy and time complexity of the proposed method has been demonstrated by both the UCI benchmark datasets and real world EEG data from BCI Competition IV Dataset 2a, respectively. PMID:26798330

  6. Advanced use of an esthetic indirect posterior resin system.

    PubMed

    Howard, N Y

    1997-10-01

    With the advent of newer indirect posterior restorative materials, one current resin restorative system still stands out as a proven leader in the dental marketplace. This article focuses on the multiple use of an all-microfill, laboratory-processed, indirect resin restorative system. Three cases are presented and criteria for long-term success are reviewed and discussed.

  7. Learning about Posterior Probability: Do Diagrams and Elaborative Interrogation Help?

    ERIC Educational Resources Information Center

    Clinton, Virginia; Alibali, Martha W.; Nathan, Mitchell J.

    2016-01-01

    To learn from a text, students must make meaningful connections among related ideas in that text. This study examined the effectiveness of two methods of improving connections--elaborative interrogation and diagrams--in written lessons about posterior probability. Undergraduate students (N = 198) read a lesson in one of three questioning…

  8. Arthroscopically assisted combined anterior and posterior cruciate ligament reconstruction.

    PubMed

    Fanelli, G C; Giannotti, B F; Edson, C J

    1996-02-01

    This article presents the minimum 2-year results (range, 24 to 48 months) of 20 arthroscopically assisted combined anterior cruciate ligament/posterior cruciate ligament (ACL/PCL) reconstructions, evaluated preoperatively and postoperatively using the Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales, and the KT 1000 knee ligament arthrometer (Medmetric Corp, San Diego, CA). There were 16 men or boys, 4 women or girls; 9 right, 11 left; 10 acute, and 10 chronic knee injuries. Ligament injuries included 1 ACL/PCL tear, 2 ACL/PCL/medial collateral ligament (MCL)/posterior lateral corner tears. 7 ACL/PCL/MCL tears, and 10 ACL/PCL/posterior lateral corner tears. ACLs were reconstructed using autograft or allograft patellar tendons. PCLs were reconstructed using allograft Achilles tendon, or autograft patellar tendon. MCL tears were successfully treated with bracing. Posterior lateral instability was successfully treated with long head of the biceps femoris tendon tenodesis. Tegner, Lysholm, and Hospital for Special Surgery knee ligament rating scales significantly improved preoperatively to postoperatively (P = .0001). Corrected anterior KT 1000 measurements improved from preoperative to postoperative status (P = .0078).

  9. FEMORAL INSERTION OF THE POSTERIOR CRUCIATE LIGAMENT: AN ANATOMICAL STUDY

    PubMed Central

    de Paula Leite Cury, Ricardo; Severino, Nilson Roberto; Camargo, Osmar Pedro Arbix; Aihara, Tatsuo; Neto, Leopoldo Viana Batista; Goarayeb, Dedley Nelson

    2015-01-01

    Objective: To identify objective parameters to guide correct location of the posterior cruciate ligament (PCL) in the femur. Methods: The PCLs of 20 human cadavers were resected. The following portions were measured: distance from the most distal portion of the PCL, close to the roof, to the most anterior edge of the cartilage (AB); distance from the most proximal portion of the PCL, close to the roof, to the most anterior cartilage (AC); distance between the two parts of the ligament close to the roof (BC); distance from the distal edge in its posterior portion, to the more posterior joint edge (DE); distance from the distal edge of the ligament in its posterior portion, to the intercondylar roof (DF); and finally, the format of the ligament insertion and area of coverage on the femoral condyle. Results: The PCL has the shape of a quarter ellipse, with an average area of 153.5mm2. The mean distances found were: AB of 2.1mm, AC of 10.7mm, BC of 8.6mm DE of 12.4mm and DF of 16.8mm. Conclusions: The edge close to the roof of the anterolateral bundle is closer to the joint cartilage (2.1mm) than the posteromedial bundle is, which is 12.4mm from the edge proximal to the cartilage. These references should assist in better and more accurate positioning of femoral tunnels in PCL reconstruction. PMID:27027059

  10. Esthetic restorations for posterior teeth: practical and clinical considerations.

    PubMed

    Magne, P; Dietschi, D; Holz, J

    1996-04-01

    The current abundance of posterior esthetic restorative materials and techniques may be confusing. This paper describes a simple and logical global concept that assists clinicians in choosing the appropriate therapeutic modality according to well-defined clinical criteria. Practical considerations about cavity preparation, base-lining, filling, luting, and finishing procedures are reviewed.

  11. Bilateral posterior shoulder dislocation after electrical shock: A case report

    PubMed Central

    Ketenci, Ismail Emre; Duymus, Tahir Mutlu; Ulusoy, Ayhan; Yanik, Hakan Serhat; Mutlu, Serhat; Durakbasa, Mehmet Oguz

    2015-01-01

    Introduction Posterior dislocation of the shoulder is a rare and commonly missed injury. Unilateral dislocations occur mostly due to trauma. Bilateral posterior shoulder dislocations are even more rare and result mainly from epileptic seizures. Electrical injury is a rare cause of posterior shoulder dislocation. Injury mechanism in electrical injury is similar to epileptic seizures, where the shoulder is forced to internal rotation, flexion and adduction. Presentation of case This report presents a case of bilateral posterior shoulder dislocation after electrical shock. We were able to find a few individual case reports describing this condition. The case was acute and humeral head impression defects were minor. Our treatment in this case consisted of closed reduction under general anesthesia and applying of orthoses which kept the shoulders in abduction and external rotation. A rehabilitation program was begun after 3 weeks of immobilization. After 6 months of injury the patient has returned to work. 20 months postoperatively, at final follow-up, he was painless and capable of performing all of his daily activities. Discussion The amount of bilateral shoulder dislocations after electrical injury is not reported but is known to be very rare. The aim of this case presentation is to report an example for this rare entity, highlight the difficulties in diagnosis and review the treatment options. Conclusion Physical examination and radiographic evaluation are important for quick and accurate diagnosis. PMID:26904192

  12. Posterior insular cortex is necessary for conditioned inhibition of fear.

    PubMed

    Foilb, Allison R; Flyer-Adams, Johanna G; Maier, Steven F; Christianson, John P

    2016-10-01

    Veridical detection of safety versus danger is critical to survival. Learned signals for safety inhibit fear, and so when presented, reduce fear responses produced by danger signals. This phenomenon is termed conditioned inhibition of fear. Here, we report that CS+/CS- fear discrimination conditioning over 5 days in rats leads the CS- to become a conditioned inhibitor of fear, as measured by the classic tests of conditioned inhibition: summation and retardation of subsequent fear acquisition. We then show that NMDA-receptor antagonist AP5 injected to posterior insular cortex (IC) before training completely prevented the acquisition of a conditioned fear inhibitor, while intra-AP5 to anterior and medial IC had no effect. To determine if the IC contributes to the recall of learned fear inhibition, injections of the GABAA agonist muscimol were made to posterior IC before a summation test. This resulted in fear inhibition per se, which obscured inference to the effect of IC inactivation with recall of the safety cue. Control experiments sought to determine if the role of the IC in conditioned inhibition learning could be reduced to simpler fear discrimination function, but fear discrimination and recall were unaffected by AP5 or muscimol, respectively, in the posterior IC. These data implicate a role of posterior IC in the learning of conditioned fear inhibitors. PMID:27523750

  13. Surface characteristics of posterior composites after polishing and toothbrushing.

    PubMed

    van Dijken, J W; Ruyter, I E

    1987-10-01

    The surface characteristics of eight posterior and two anterior composite resins were studied by SEM and profilometric tracings. The materials included both chemically cured and light-cured resin systems. Two posterior materials were microfilled composites; the others were conventional or hybrid types. The anterior composites were of conventional and hybrid types. At various steps in the procedures the following polishing/brushing treatments were evaluated: 1) dry polishing with Sof-lex discs followed by brushing with toothpaste; and 2) wet polishing with diamond pastes of increasing fineness, followed by brushing with toothpaste. The base line before the polishing/brushing procedures was obtained by wet polishing on silicon-carbide paper (4000 grit). All materials could be polished to a comparable smoothness by the Sof-lex discs, but this polishing procedure was associated with the development of an amorphous surface layer. Polishing with diamond pastes gave various results, with a 20-fold difference in surface roughness values from the smoothest to the roughest material. Toothbrushing after polishing with the Sof-lex system increased the surface roughness for all materials, but to various degrees. The two microfilled and four of the conventional posterior composites showed comparable surface roughness values, whereas two remaining posterior and the two anterior materials showed two to three times higher surface roughness values after toothbrushing. PMID:3478939

  14. Tibialis Anterior Tendon Transfer for Posterior Tibial Tendon Insufficiency.

    PubMed

    Ramanujam, Crystal L; Stapleton, John J; Zgonis, Thomas

    2016-01-01

    The Cobb procedure is useful for addressing stage 2 posterior tibial tendon dysfunction and is often accompanied by a medial displacement calcaneal osteotomy and/or lateral column lengthening. The Cobb procedure can also be combined with selected medial column arthrodesis and realignment osteotomies along with equinus correction when indicated. PMID:26590721

  15. Frontal and posterior subtypes of neuropsychological deficit in Parkinson's disease.

    PubMed

    Miller, Ivy N; Neargarder, Sandy; Risi, Megan M; Cronin-Golomb, Alice

    2013-04-01

    Mild cognitive impairment in Parkinson's disease (PD) is heterogeneous in regard to affected domains. Although patterns of cognitive performance that may predict later dementia are as yet undetermined, posterior- versus frontal-type assessments show promise for differential predictive value. The present study included 70 individuals: 42 with idiopathic PD without dementia and 28 age- and education-matched healthy control adults (HC). Participants completed assessments of cognition with emphasis on tests that are sensitive to frontal and posterior deficits. PD patients were classified into cognitive subgroups and the subgroups were compared on demographic and disease variables. Individual performance across neuropsychological tests was evaluated for the PD group. Patients with PD performed more poorly than HC on several measures of cognition, and they were classified into frontal (12), posterior (3), both (10) and neither subgroups (17), the latter two in reference to frontal- and posterior-type deficits. The neither subgroup was distinguished by less motor impairment than the both subgroup, but the four subgroups did not otherwise differ on demographic or disease variables. Across patients, the tests most sensitive to cognitive impairment included measures of attention and executive functioning (frontal-type tests). Examination of individual test performance for PD revealed substantial heterogeneity across tests with respect to number and severity of deficits. The current study provides insight into which commonly used neuropsychological tests are most sensitive to cognitive deficits (strictly defined) in a nondemented, well characterized PD sample, and into the relation of cognitive subgroups to demographic and disease-specific variables.

  16. Posterior Cortical Atrophy Presenting with Superior Arcuate Field Defect.

    PubMed

    Wan, Sue Ling; Bukowska, Danuta M; Ford, Stephen; Chen, Fred K

    2015-01-01

    An 80-year-old female with reading difficulty presented with progressive arcuate field defect despite low intraocular pressure. Over a 5-year period, the field defect evolved into an incongruous homonymous hemianopia and the repeated neuroimaging revealed progressive posterior cortical atrophy. Further neuropsychiatric assessment demonstrated symptoms and signs consistent with Benson's syndrome. PMID:26417467

  17. Fasciotomy of the posterior femoral muscle compartment in athletes.

    PubMed

    Orava, S; Rantanen, J; Kujala, U M

    1998-01-01

    Over a period of 13 years fasciotomy was performed on 46 athletes with chronic pain located at the posterior femoral muscle compartment. The patients could be divided, according to the etiology, in two groups: exertion (26 patients) and trauma (20 patients). In the first group the symptoms appeared without any sudden trauma and most of the athletes competed in endurance sports (e.g. 16 long distance runners). In the second group there was a history of hamstring muscle rupture or recurrent injuries. The symptoms were dull pain, stiffness, cramps and weakness of the posterior thigh during and after training. Conservative treatment methods did not help to eliminate the symptoms during a long preoperative follow-up period. Posterior fasciotomy (minimum 20 cm) to the thigh was performed through one or two incisions. In four patients a simultaneous liberation, division or suturation of the muscle scar was done. The patients were followed up for 19 months and the results of the fasciotomy were good or excellent in 39 cases. Pain at the posterior thigh muscle compartment may sometimes become chronic and hamper the training of athletes. Fasciotomy seems to be an effective method to help these patients return to their previous level of sports.

  18. Posterior approaches for symptomatic metastatic spinal cord compression.

    PubMed

    Molina, Camilo; Goodwin, C Rory; Abu-Bonsrah, Nancy; Elder, Benjamin D; De la Garza Ramos, Rafael; Sciubba, Daniel M

    2016-08-01

    Surgical interventions for spinal metastasis are commonly performed for mechanical stabilization, pain relief, preservation of neurological function, and local tumor reduction. Although multiple surgical approaches can be used for the treatment of metastatic spinal lesions, posterior approaches are commonly performed. In this study, the role of posterior surgical procedures in the treatment of spinal metastases was reviewed, including posterior laminectomy with and without instrumentation for stabilization, transpedicular corpectomy, and costotransversectomy. A review of the literature from 1980 to 2015 was performed using Medline, as was a review of the bibliographies of articles meeting preset inclusion criteria, to identify studies on the role of these posterior approaches among adults with spinal metastasis. Thirty-four articles were ultimately analyzed, including 1 randomized controlled trial, 6 prospective cohort studies, and 27 retrospective case reports and/or series. Some of the reviewed articles had Level II evidence indicating that laminectomy with stabilization can be recommended for improvement in neurological outcome and reduction of pain in selected patients. However, the use of laminectomy alone should be carefully considered. Additionally, transpedicular corpectomy and costotransversectomy can be recommended with the expectation of improving neurological outcomes and reducing pain in properly selected patients with spinal metastases. With improvements in the treatment paradigms for patients with spinal metastasis, as well as survival, surgical therapy will continue to play an important role in the management of spinal metastasis. While this review presents a window into determining the utility of posterior approaches, future prospective studies will provide essential data to better define the roles of the various options now available to surgeons in treating spinal metastases. PMID:27476835

  19. Posterior Ankle Structure Injury During Total Ankle Replacement.

    PubMed

    Reb, Christopher W; McAlister, Jeffrey E; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management. PMID:27291681

  20. Clinical, FDG and amyloid PET imaging in posterior cortical atrophy.

    PubMed

    Singh, Tarun D; Josephs, Keith A; Machulda, Mary M; Drubach, Daniel A; Apostolova, Liana G; Lowe, Val J; Whitwell, Jennifer L

    2015-06-01

    The purpose of this study was to identify the clinical, [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and amyloid-PET findings in a large cohort of posterior cortical atrophy (PCA) patients, to examine the neural correlates of the classic features of PCA, and to better understand the features associated with early PCA. We prospectively recruited 25 patients who presented to the Mayo Clinic between March 2013 and August 2014 and met diagnostic criteria for PCA. All patients underwent a standardized set of tests and amyloid imaging with [(11)C] Pittsburg compound B (PiB). Seventeen (68 %) underwent FDG-PET scanning. We divided the cohort at the median disease duration of 4 years in order to assess clinical and FDG-PET correlates of early PCA (n = 13). The most common clinical features were simultanagnosia (92 %), dysgraphia (68 %), poly-mini-myoclonus (64 %) and oculomotor apraxia (56.5 %). On FDG-PET, hypometabolism was observed bilaterally in the lateral and medial parietal and occipital lobes. Simultanagnosia was associated with hypometabolism in the right occipital lobe and posterior cingulum, optic ataxia with hypometabolism in left occipital lobe, and oculomotor apraxia with hypometabolism in the left parietal lobe and posterior cingulate gyrus. All 25 PCA patients were amyloid positive. Simultanagnosia was the only feature present in 85 % of early PCA patients. The syndrome of PCA is associated with posterior hemisphere hypometabolism and with amyloid deposition. Many of the classic features of PCA show associated focal, but not widespread, areas of involvement of these posterior hemispheric regions. Simultanagnosia appears to be the most common and hence sensitive feature of early PCA. PMID:25862483

  1. Arthroscopic Treatment of Posterior Impingement of the Hindfoot

    PubMed Central

    Carreira, Dominic S.; Vora, Anand Mahesh; Kozy, John

    2015-01-01

    Objectives: Open and arthroscopic techniques have been utilized in the treatment of posterior impingement of the ankle and hindfoot. Because posterior impingement occurs more frequently in patients who repetitively plantarflex the ankle, this population may especially benefit from a procedure that reduces pain and results in maximal range of motion (ROM). The purpose of this study was to assess the outcome of hindfoot endoscopy in patients with posterior ankle impingement through higher level of function outcome measures and physical examination parameters, focused on analysis of ROM. Methods: 20 ankles (19 patients) were followed prospectively at a minimum 1 year follow-up (mean 38.2 months). 19 of 20 patients were competitive athletes. Patients completed a minimum of 3 months of nonoperative treatment. Diagnoses included os trigonum, tibial exostosis, talar exostosis, loose body or fracture nonunion, and ganglion cyst removal. Patients underwent arthroscopic treatment utilizing a posterior approach; all relevant pathology was addressed. Post-surgery, patients were placed in a splint for 3 to 7 days then placed in a CAM boot for 2 to 3 weeks, weight bearing as tolerated. Physical therapy was initiated within 7-10 days; strengthening exercises were initiated postoperatively at 1 month. Results: At most recent follow-up, VAS Pain and AOFAS Hindfoot scores showed significant improvement (p<0.01) pre to post-operatively; Tegner score remained unchanged (p=0.888). 3 patients were professional athletes; all returned to their previous level of professional activity. ROM variables between affected and unaffected sides reached statistical similarity at most recent follow-up. 15% of patients reported post-operative neuritis. No other complications were reported. Conclusion: Posterior ankle arthroscopy allows for maintenance or restoration of anatomic ROM of the ankle and hindfoot, ability to return to at least previous level of activity, and improvement in objective

  2. Posterior Ankle Structure Injury During Total Ankle Replacement.

    PubMed

    Reb, Christopher W; McAlister, Jeffrey E; Hyer, Christopher F; Berlet, Gregory C

    2016-01-01

    Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management.

  3. Biochemical Reversal of Aging

    NASA Astrophysics Data System (ADS)

    Ely, John T. A.

    2006-03-01

    We cite our progress on biochemical reversal of aging. However, it may be circa 2 years before we have necessary substances at low cost. Meanwhile, without them, a number of measures can be adopted providing marked improvement for the problems of aging in modern societies. For example, enzymes are needed to excrete toxins that accelerate aging; Hg is the ultimate toxin that disables all enzymes (including those needed to excrete Hg itself). Low Hg level in the urine, due to loss of excretory ability, causes the diagnosis of Hg toxicity to almost always be missed. Hg sources must be removed from the body! Another example is excess sugar; hyperglycemia decreases intracellular ascorbic acid (AA) by competitively inhibiting the insulin- mediated active transport of AA into cells. Thus, immunity is impaired by low leucocyte AA. AA is needed for new proteins in aging tissues. Humans must supplement AA; their need same as in AA-synthesizing mammals.

  4. Reverse slapper detonator

    SciTech Connect

    Weingart, Richard C.

    1990-01-01

    A reverse slapper detonator (70), and methodology related thereto, are provided. The detonator (70) is adapted to be driven by a pulse of electric power from an external source (80). A conductor (20) is disposed along the top (14), side (18), and bottom (16) surfaces of a sheetlike insulator (12). Part of the conductor (20) comprises a bridge (28), and an aperture (30) is positioned within the conductor (20), with the bridge (28) and the aperture (30) located on opposite sides of the insulator (12). A barrel (40) and related explosive charge (50) are positioned adjacent to and in alignment with the aperture (30), and the bridge (28) is buttressed with a backing layer (60). When the electric power pulse vaporizes the bridge (28), a portion of the insulator (12) is propelled through the aperture (30) and barrel (40), and against the explosive charge (50), thereby detonating it.

  5. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2006-04-25

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  6. Multiple stimulus reversible hydrogels

    DOEpatents

    Gutowska, Anna; Krzyminski, Karol J.

    2003-12-09

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  7. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  8. Properly apply reverse osmosis

    SciTech Connect

    Kucera, J.

    1997-02-01

    Reverse osmosis (RO) is a water purification technique used to reduce the loading of dissolved solids in solution. The popularity of RO for treating boiler feedwater is growing because of the rising cost of ion-exchange-based demineralization as well as safety concerns associated with handling acid and caustic. A properly designed and operated RO-based boiler-feedwater-treatment system can reduce the load to, and costs associated with, ion exchange demineralization. This article discusses RO feedwater quality recommendations, pretreatment techniques, and system monitoring necessary to achieve optimum RO system performance in the most cost-effective manner. Regardless of the application--whether it is the treatment of boiler feedwater, industrial wastewater, or process water--the approach to pretreatment and the other design and operating guidance offered here remains the same.

  9. Reverse Osmosis Optimization

    SciTech Connect

    McMordie Stoughton, Kate; Duan, Xiaoli; Wendel, Emily M.

    2013-08-26

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

  10. Reverse Osmosis Optimization

    SciTech Connect

    2013-08-01

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.

  11. Reverse photoacoustic standoff spectroscopy

    DOEpatents

    Van Neste, Charles W.; Senesac, Lawrence R.; Thundat, Thomas G.

    2011-04-12

    A system and method are disclosed for generating a reversed photoacoustic spectrum at a greater distance. A source may emit a beam to a target and a detector measures signals generated as a result of the beam being emitted on the target. By emitting a chopped/pulsed light beam to the target, it may be possible to determine the target's optical absorbance by monitoring the intensity of light collected at the detector at different wavelengths. As the wavelength of light is changed, the target may absorb or reject each optical frequency. Rejection may increase the intensity at the sensing element and absorption may decrease the intensity. Accordingly, an identifying spectrum of the target may be made with the intensity variation of the detector as a function of illuminating wavelength.

  12. Oxytocin Expression and Function in the Posterior Retina: A Novel Signaling Pathway

    PubMed Central

    Halbach, Patrick; Pillers, De-Ann M.; York, Nathaniel; Asuma, Matti P.; Chiu, Michelle A.; Luo, Wenxiang; Tokarz, Sara; Bird, Ian M.; Pattnaik, Bikash R.

    2015-01-01

    Purpose. Oxytocin (OXT) is recognized as an ubiquitously acting nonapeptide hormone that is involved in processes ranging from parturition to neural development. Its effects are mediated by cell signaling that occurs as a result of oxytocin receptor (OXTR) activation. We sought to determine whether the OXT-OXTR signaling pathway is also expressed within the retina. Methods. Immunohistochemistry using cell-specific markers was used to localize OXT within the rhesus retina. Reverse transcriptase PCR and immunohistochemistry were used to assess the expression of OXTR in both human and rhesus retina. Single-cell RT-PCR and Western blot analyses were used to determine the expression of OXTR in cultured human fetal RPE (hfRPE) cells. Human fetal RPE cells loaded with FURA-2 AM were studied by ratiometric Ca2+ imaging to assess transient mobilization of intracellular Ca2+ ([Ca2+]i). Results. Oxytocin was expressed in the cone photoreceptor extracellular matrix of the rhesus retina. Oxytocin mRNA and protein were expressed in the human and rhesus RPE. Oxytocin mRNA and protein expression were observed in cultured hfRPE cells, and exposure of these cells to 100 nM OXT induced a transient 79 ± 1.5 nM increase of [Ca2+]i. Conclusions. Oxytocin and OXTR are present in the posterior retina, and OXT induces an increase in hfRPE [Ca2+]i. These results suggest that the OXT-OXTR signaling pathway is active in the retina. We propose that OXT activation of the OXTR occurs in the posterior retina and that this may serve as a paracrine signaling pathway that contributes to communication between the cone photoreceptor and the RPE. PMID:25593022

  13. Posterior shoulder pain and anterior instability: a preliminary clinical study.

    PubMed

    Castagna, Alessandro; Conti, Marco; Borroni, Mario; Massazza, Giuseppe; Vinci, Enzo; Franceschi, Giorgio; Garofalo, Raffaele

    2008-02-01

    Different clinical tests have been suggested in the literature as significant indicators of anterior shoulder instability. Sometimes patients with recurrent anterior shoulder instability may show some muscular guarding thus making the evaluation of specific clinical tests very difficult. These patients may also report a medical history with posterior shoulder pain that can be also elicited during some clinical manoeuvres. From September 2005 to September 2006 we prospectively studied patients who underwent an arthroscopic anterior capsuloplasty. Shoulder clinical examination was performed including anterior shoulder instability tests (drawer, apprehension and relocation tests). Furthermore the exam was focused on the presence of scapular dyskinesia and posterior shoulder pain. The patients were also evaluated with ASES, Rowe, SST (Simple Shoulder Test), Constant and UCLA (University of California at Los Angeles) scoring system preoperatively and at the latest follow-up time. In the period of this study we observed 16 patients treated for anterior gleno-humeral arthroscopic stabilisation, who preoperatively complained also of a posterior scapular pain. The pain was referred at the level of lower trapezium and upper rhomboids tendon insertion on the medial border of the scapula. It was also reproducible upon local palpation by the examiner. Four of these patients also referred pain in the region of the insertion of the infraspinatus and teres minor. After arthroscopic stabilisation the shoulder was immobilised in a sling with the arm in the neutral rotation for a period of 4 weeks. A single physician supervised shoulder rehabilitation. After a mean time of 6.8 months of follow-up, all the shoulder scores were significantly improved and, moreover, at the same time the patients referred the disappearance of the posterior pain. Posterior scapular shoulder pain seems to be another complaint and sign that can be found in patients affected by anterior shoulder instability

  14. Defining the Polar Field Reversal

    NASA Technical Reports Server (NTRS)

    Upton, Lisa; Hathaway, David H.

    2013-01-01

    The polar fields on the Sun are directly related to solar cycle variability. Recently there has been interest in studying an important characteristic of the polar fields: the timing of the polar field reversals. However this characteristic has been poorly defined, mostly due to the limitations of early observations. In the past, the reversals have been calculated by averaging the flux above some latitude (i.e. 55deg or 75deg). Alternatively, the reversal could be defined by the time in which the previous polarity is completely canceled and replaced by the new polarity at 90de, precisely at the pole. We will use a surface flux transport model to illustrate the differences in the timing of the polar field reversal based on each of these definitions and propose standardization in the definition of the polar field reversal. The ability to predict the timing of the polar field reversal using a surface flux transport model will also be discussed.

  15. Geomagnetic Reversals during the Phanerozoic.

    PubMed

    McElhinny, M W

    1971-04-01

    An antalysis of worldwide paleomagnetic measurements suggests a periodicity of 350 x 10(6) years in the polarity of the geomagnetic field. During the Mesozoic it is predominantly normal, whereas during the Upper Paleozoic it is predominantly reversed. Although geomagnetic reversals occur at different rates throughout the Phanerozoic, there appeaars to be no clear correlation between biological evolutionary rates and reversal frequency. PMID:17735224

  16. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  17. A case of hypospadias, anterior and posterior urethral valves.

    PubMed

    Carvell, James; Mulik, Roopa

    2013-01-01

    This report outlines the case of a 3-year-old boy whose initial presentation was that of asymptomatic hypertension (lowest recording 148/90), found at preoperative check prior to stage 2-correction surgery for distal hypospadias. Upon diagnosis of true hypertension, an ultrasound of the child's renal tract showed evidence of marked hydronephrosis and calyceal dilatation. On the background of deteriorating renal function (Urea 25.5 and Creatinine 188), a Micturating Cystourethrogram was performed, demonstrating posterior urethral dilatation. With difficulties controlling blood pressure, the child was transferred to Urology care, where resection of a posterior urethral valve (PUV) was undertaken. Despite this, renal function deteriorated further and re-cystoscopy identified an anterior urethral valve (AUV), which was also resected. Renal function, although improved, remains poor and blood pressure is controlled with two anti-hypertensives. To the publisher's knowledge, the association between hypospadias, PUVs and AUVs is as yet undocumented. PMID:24964414

  18. Posterior Tibial Tendon Dysfunction: An Overlooked Cause of Foot Deformity

    PubMed Central

    Bubra, Preet Singh; Keighley, Geffrey; Rateesh, Shruti; Carmody, David

    2015-01-01

    Posterior tibial tendon dysfunction is the most common cause of adult acquired flatfoot. Degenerative changes in this tendon, lead to pain and weakness and if not identified and treated will progress to deformity of the foot and degenerative changes in the surrounding joints. Patients will complain of medial foot pain, weakness, and a slowly progressive foot deformity. A “too many toes” sign may be present and patients will be unable to perform a single heal raise test. Investigations such X-ray, ultrasound and magnetic resonance imaging will help stage the disease and decide on management. The optimal manage may change based on the progression of deformity and stage of disease. Early identification and prompt initiation of treatment can halt progression of the disease. The purpose of this article is to examine the causes, signs, symptoms, examinations, investigations and treatment options for posterior tibial tendon dysfunction. PMID:25810985

  19. Delayed supratentorial intracerebral hemorrhage following posterior fossa surgery

    PubMed Central

    Salunke, Pravin; Malik, Vinod; Kovai, Priyamvadha; Aggarwal, Ashish; Khandelwal, Niranjan K.

    2016-01-01

    Delayed supratentorial intracerebral hematoma after posterior fossa surgery is uncommon. Only few cases have been reported in the past. The cause has been attributed to sitting position leading to changes in intracranial arterial and venous pressures. We report two cases of delayed intracerebral hematoma following posterior fossa surgery, none of which were operated in sitting position. MR venogram done in one patient showed venous sinus thrombosis. Intracererbal hematoma following infratentorial surgery is uncommon and is possibly due to venous sinus thrombosis leading to venous hypertension. Control of bleeding from venous sinuses due to avulsion of emissary veins during craniotomy/craniectomy possibly induces sinus thrombosis that may propagate antegrade or retrograde, leading to venous hypertension and parenchymal bleed. PMID:27366274

  20. Handling characteristics of resin composites in posterior teeth.

    PubMed

    Ferrari, M; Kugel, G

    1998-09-01

    In the last 10 years, tremendous improvements in strength and shade selection for resin composites have been achieved. Also, a new generation of enamel-dentin bonding systems has been developed, and patient expectations of esthetic treatment have risen. Several techniques are available for restoring posterior teeth. When a caries lesion is limited, a direct esthetic restoration is indicated. Essential elements for obtaining good, long-term clinical results for direct esthetic restorations of posterior teeth are: (1) cavity preparation; (2) knowledge of the characteristics of the three dental substrates; (3) rubber dam use and matrix and wedge placement; (4) correct use of the enamel-dentin bonding system; (5) proper selection of the resin composite material; (6) use of the multilayering technique; (7) finishing and polishing procedures; and (8) maintenance of the restoration.

  1. Direct and semi-direct posterior composite restorations.

    PubMed

    Spreafico, R

    1996-09-01

    Since the introduction of composite resins in dentistry, the adhesive properties of the material to enamel and dentin surfaces have been improved considerably, resulting in more conservative cavity preparation and the preservation of natural tooth structure. Patient demand for aesthetic metal-free restorations in the posterior region has resulted in the utilization of tooth-colored composite restorations. The primary disadvantage of composite resins-material shrinkage-can be minimized, but not eliminated. Various techniques have been developed and proposed in order to overcome this important limitation. The learning objective of this article is to provide indications for the direct and semi-direct techniques and to illustrate effective clinical procedures for placement of posterior composite resin restorations. The article outlines the treatment concepts, principles of cavity preparation, direct and semi-direct restorative methods, and the technique-sensitive luting procedures. Several cases are used to illustrate the clinical aspects.

  2. Management of noninfectious posterior uveitis with intravitreal drug therapy

    PubMed Central

    Tan, Hui Yi; Agarwal, Aniruddha; Lee, Cecilia S; Chhablani, Jay; Gupta, Vishali; Khatri, Manoj; Nirmal, Jayabalan; Pavesio, Carlos; Agrawal, Rupesh

    2016-01-01

    Uveitis is an important cause of vision loss worldwide due to its sight-threatening complications, especially cystoid macular edema, as well as choroidal neovascularization, macular ischemia, cataract, and glaucoma. Systemic corticosteroids are the mainstay of therapy for noninfectious posterior uveitis; however, various systemic side effects can occur. Intravitreal medication achieves a therapeutic level in the vitreous while minimizing systemic complications and is thus used as an exciting alternative. Corticosteroids, antivascular endothelial growth factors, immunomodulators such as methotrexate and sirolimus, and nonsteroidal anti-inflammatory drugs are currently available for intravitreal therapy. This article reviews the existing literature for efficacy and safety of these various options for intravitreal drug therapy for the management of noninfectious uveitis (mainly intermediate, posterior, and panuveitis). PMID:27789936

  3. SHOULDER POSTERIOR INTERNAL IMPINGEMENT IN THE OVERHEAD ATHLETE

    PubMed Central

    Grant‐Nierman, Meggan; Lucas, Brennen

    2013-01-01

    Posterior internal impingement (PII) of the glenohumeral joint is a common cause of shoulder complex pain in the overhead athlete. This impingement is very different from standard outlet impingement seen in shoulder patients. Internal impingement is characterized by posterior shoulder pain when the athlete places the humerus in extreme external rotation and abduction as in the cocking phase of pitching or throwing. Impingement in this position occurs between the supraspinatus and or infraspinatus and the glenoid rim. Understanding regarding this pathology continues to evolve. Definitive understanding of precipitating factors, causes, presentation and methods of treatment have yet to be determined. A high index of suspicion should be used when attempting to make this diagnosis. This current concepts review presents the current thinking regarding pathophysiology, evaluation, and treatment of this condition. Level of Evidence: 5 PMID:23593557

  4. [Cysts in the posterior triangle of the neck in adults].

    PubMed

    Brea-Álvarez, Beatriz; Roldán-Hidalgo, Amaya

    2015-01-01

    Cystic lesions of the posterior triangle are a pathologic entity whose diagnosis is made in the first two years of life. Its presentation in adulthood is an incidental finding and the differential diagnosis includes cystic lymphangioma, lymphatic metastasis of thyroid cancer and branchial cyst. Often with the finding of a cervical lump, FNA is made before diagnostic imaging is performed, however, this procedure is not always advisable. We reviewed the cases of patients who came last year to our department with a cystic mass in this location and correlating the imaging findings with pathologic specimen. We show characteristic findings of these lesions in order to make an early diagnosis and thus to get the approach and treatment appropriate of adult patients with a cystic lesion in the posterior cervical triangle.

  5. Markov chain Monte Carlo posterior sampling with the Hamiltonian method.

    SciTech Connect

    Hanson, Kenneth M.

    2001-01-01

    A major advantage of Bayesian data analysis is that provides a characterization of the uncertainty in the model parameters estimated from a given set of measurements in the form of a posterior probability distribution. When the analysis involves a complicated physical phenomenon, the posterior may not be available in analytic form, but only calculable by means of a simulation code. In such cases, the uncertainty in inferred model parameters requires characterization of a calculated functional. An appealing way to explore the posterior, and hence characterize the uncertainty, is to employ the Markov Chain Monte Carlo technique. The goal of MCMC is to generate a sequence random of parameter x samples from a target pdf (probability density function), {pi}(x). In Bayesian analysis, this sequence corresponds to a set of model realizations that follow the posterior distribution. There are two basic MCMC techniques. In Gibbs sampling, typically one parameter is drawn from the conditional pdf at a time, holding all others fixed. In the Metropolis algorithm, all the parameters can be varied at once. The parameter vector is perturbed from the current sequence point by adding a trial step drawn randomly from a symmetric pdf. The trial position is either accepted or rejected on the basis of the probability at the trial position relative to the current one. The Metropolis algorithm is often employed because of its simplicity. The aim of this work is to develop MCMC methods that are useful for large numbers of parameters, n, say hundreds or more. In this regime the Metropolis algorithm can be unsuitable, because its efficiency drops as 0.3/n. The efficiency is defined as the reciprocal of the number of steps in the sequence needed to effectively provide a statistically independent sample from {pi}.

  6. Hyperintense Acute Reperfusion Marker on FLAIR in Posterior Circulation Infarction

    PubMed Central

    Wenz, Holger; Böhme, Johannes; Al-Zghloul, Mansour; Groden, Christoph

    2016-01-01

    Purpose In the present study, we aimed to investigate the frequency of blood brain barrier injury in posterior circulation infarction as demonstrated by the hyperintense acute reperfusion marker (HARM) on fluid attenuated inversion recovery images (FLAIR). Methods From a MRI report database we identified patients with posterior circulation infarction who underwent MRI, including perfusion-weighted images (PWI), within 12 hours after onset and follow-up MRI within 24 hours and analyzed diffusion-weighted images (DWI), PWI, FLAIR, and MR angiography (MRA). On FLAIR images, the presence of HARM was noted by using pre-specified criteria (focal enhancement in the subarachnoid space and/or the ventricles). Results Overall 16 patients (median age of patients 68.5 (IQR 55.5–82.75) years) with posterior circulation infarction were included. Of these, 13 (81.3%) demonstrated PCA occlusion, and 3 (18.7%) patients BA occlusion on MRA. Initial DWI demonstrated ischemic lesions in the thalamus (68.8%), splenium (18.8%), hippocampus (75%), occipital lobe (81.3%), mesencephalon (18.8%), pons (18.8%), and cerebellum (50%). On follow-up MRA recanalization was noted in 10 (62.5%) patients. On follow-up FLAIR images, HARM was observed in 8 (50%) patients. In all of these, HARM was detected remote from the acute ischemic lesion. HARM was more frequently observed in patients with vessel recanalization (p = 0.04), minor infarction growth (p = 0.01), and smaller ischemic lesions on follow-up DWI (p = 0.05). Conclusions HARM is a frequent finding in posterior circulation infarction and associated with vessel recanalization, minor infarction growth as well as smaller infarction volumes in the course. Neuroradiologists should be cognizant of the fact that HARM may be present on short interval follow-up FLAIR images in patients with acute ischemic infarction who initially underwent MRI and received intravenous gadolinium-based contrast agents. PMID:27326459

  7. Superior Labral Anterior Posterior Lesions of the Shoulder

    PubMed Central

    Malal, Joby Jacob George; Khan, Yousaf; Farrar, Graville; Waseem, Mohammed

    2013-01-01

    Superior labrum anterior and posterior (SLAP) lesion is of fairly recent description and its understanding is rapidly evolving. Its incidence and need for surgical treatment has increased exponentially in line with the increase in shoulder arthroscopies. It is of particular importance in the elite over head athlete and the young. A range of arthroscopic techniques and devices have been described with good functional results. The ability to return to pre injury level of sports remains a concern. PMID:24082975

  8. Recent trends in esthetic restorations for posterior teeth.

    PubMed

    Dietschi, D; Magne, P; Holz, J

    1994-10-01

    The increase in the demands made by patients for esthetic or metal-free restorations, together with the ever-growing interest shown by the dental profession for tooth-colored materials and techniques, led to the current development of posterior adhesive restorations. This paper reviews critical elements such as adhesion to dental hard tissues as well as current properties of bases/liners, filling materials, and luting materials. A rationale for the successful use of currently available restorative systems is presented.

  9. Popliteal artery injury during posterior cruciate ligament reconstruction.

    PubMed

    Cenni, Marcos Henrique Frauendorf; do Nascimento, Bruno Fajardo; Carneiro, Guilherme Galvão Barreto; de Andrade, Rodrigo Cristiano; Pinheiro Júnior, Lúcio Flávio Biondi; Nicolai, Oscar Pinheiro

    2015-01-01

    This study reports a case of popliteal artery injury during arthroscopic reconstruction of the posterior cruciate ligament. The evolution of the injury is described and comments are made regarding the anatomy of this artery and potential risks of this surgical technique. This study had the aims of alerting the medical community, especially knee surgeons, regarding a severe surgical complication and discussing the ways of preventing it.

  10. Transient Presyncope Secondary to Posterior Descending Artery Occlusion

    PubMed Central

    Moffat, Andrew D.; Al-Khatib, Jamal T.; Michael, Jennifer; Nguyen, Vien X.

    2011-01-01

    We describe the case of a 64-year-old male initially presenting with presyncope and bradycardia, without any anginal symptoms or objective evidence of myocardial ischemia. A stress test induced no physical symptoms but revealed a left bundle branch block with multiple preventricular contractions on electrocardiogram. Subsequent catheterization revealed severe obstructive disease throughout the coronary arteries. He was treated percutaneously on two separate heart catheterizations. The presyncope and bradycardia resolved after reperfusion of the posterior descending artery. PMID:24826229

  11. Expression Patterns of Extracellular Matrix Proteins during Posterior Commissure Development

    PubMed Central

    Stanic, Karen; Saldivia, Natalia; Förstera, Benjamín; Torrejón, Marcela; Montecinos, Hernán; Caprile, Teresa

    2016-01-01

    Extracellular matrix (ECM) molecules are pivotal for central nervous system (CNS) development, facilitating cell migration, axonal growth, myelination, dendritic spine formation, and synaptic plasticity, among other processes. During axon guidance, the ECM not only acts as a permissive or non-permissive substrate for navigating axons, but also modulates the effects of classical guidance cues, such as netrin or Eph/ephrin family members. Despite being highly important, little is known about the expression of ECM molecules during CNS development. Therefore, this study assessed the molecular expression patterns of tenascin, HNK-1, laminin, fibronectin, perlecan, decorin, and osteopontin along chick embryo prosomere 1 during posterior commissure development. The posterior commissure is the first transversal axonal tract of the embryonic vertebrate brain. Located in the dorso-caudal portion of prosomere 1, posterior commissure axons primarily arise from the neurons of basal pretectal nuclei that run dorsally to the roof plate midline, where some turn toward the ipsilateral side. Expressional analysis of ECM molecules in this area these revealed to be highly arranged, and molecule interactions with axon fascicles suggested involvement in processes other than structural support. In particular, tenascin and the HNK-1 epitope extended in ventro-dorsal columns and enclosed axons during navigation to the roof plate. Laminin and osteopontin were expressed in the midline, very close to axons that at this point must decide between extending to the contralateral side or turning to the ipsilateral side. Finally, fibronectin, decorin, and perlecan appeared unrelated to axonal pathfinding in this region and were instead restricted to the external limiting membrane. In summary, the present report provides evidence for an intricate expression of different extracellular molecules that may cooperate in guiding posterior commissure axons. PMID:27733818

  12. Mesh erosion after laparoscopic posterior rectopexy: A rare complication.

    PubMed

    Mathew, Mittu J; Parmar, Amit K; Reddy, Prasanna K

    2014-01-01

    Laparoscopic posterior mesh rectopexy (LPMR) is now an accepted surgical treatment for complete rectal prolapse. It is associated with complications such as partial mucosal prolapse, fecal impaction, constipation, and rarely recurrence. Erosion of the mesh into the rectum after LPMR is very rare. We report herein the case of 40-year-old man who presented with mesh erosion into the rectum and managed successfully by the laparoscopic excision of mesh. This is probably the first such case managed by the laparoscopic approach.

  13. Posterior dislocation of the hip while playing basketball.

    PubMed

    Tennent, T D; Chambler, A F; Rossouw, D J

    1998-12-01

    Injuries in basketball are usually to the ankles and knees. Dislocation of the hip is usually associated with severe trauma--for example, road traffic accidents. A case is reported here in which a 22 year old club basketball player slipped on landing from a jump shot, forcing him into a side splits position from which he sustained a posterior dislocation of the hip resulting in a sciatic nerve palsy.

  14. Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors.

    PubMed

    Fujiwara, Yasushi; Manabe, Hideki; Sumida, Tadayoshi; Tanaka, Nobuhiro; Hamasaki, Takahiko

    2015-12-01

    Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations. The posterior extradural approach is the most common; however, it remains challenging due to severe epidural veins. Although regression of pseudotumors after fusion surgery has been reported, direct decompression and a pathologic diagnosis are ideal when the pseudotumor is large. We therefore developed a new microscopic surgical technique; transdural resection. After C1 laminectomy, the dorsal and ventral dura was incised while preserving the arachnoid. Removal of the pseudotumor was performed and both of the dura were repaired. The patient's clinical symptoms subsequently improved and the pathologic findings showed degenerative fibrocartilaginous tissue. In addition, no neurological deterioration, central spinal fluid leakage, or arachnoiditis was observed. Currently, the usefulness of the transdural approach has been reported for cervical and thoracic disk herniation. According to our results, the transdural approach is recommended for resection of retro-odontoid pseudotumors because it enables direct decompression of the spinal cord and a pathologic diagnosis. PMID:26544168

  15. Automated measurement of anterior and posterior acetabular sector angles

    NASA Astrophysics Data System (ADS)

    Ibragimov, Bulat; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

    2012-03-01

    In this paper, we propose a segmentation algorithm by which anatomical landmarks on the pelvis are extracted from computed tomography (CT) images. The landmarks are used to automatically define the anterior (AASA) and posterior acetabular sector angles (PASA) describing the degree of hip misalignment. The center of each femoral head is obtained by searching for the point at which most intensity gradient vectors defined at edge points intersect. The radius of each femoral head is computed by finding the sphere, positioned at the center of the femoral head, for which the normalized sum of gradient vector magnitudes on the sphere surface is maximal. The anterior and posterior corners of each acetabulum are searched for on a curve representing the acetabulum and defined by dynamic programming. The femoral head centers and anterior and posterior corners are used to calculate the AASA and PASA. The algorithm was applied to CT images of 120 normal subjects and the results were compared to ground truth values obtained by manual segmentation. The mean absolute difference (+/- standard deviation) between the obtained and ground truth values was 1.3 +/- 0.3 mm for the femoral head centers and 2.1 +/- 1.3 degrees for the acetabular angles.

  16. Is biologic width of anterior and posterior teeth similar?

    PubMed

    Rasouli Ghahroudi, Amir Alireza; Khorsand, Afshin; Yaghobee, Siamak; Haghighati, Farideh

    2014-01-01

    The biologic width (BW) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD) as well as the distance between free gingival margin and the bone crest (FB) of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm) was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002). BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments. PMID:25325207

  17. Human posterior auditory cortex gates novel sounds to consciousness.

    PubMed

    Jääskeläinen, Iiro P; Ahveninen, Jyrki; Bonmassar, Giorgio; Dale, Anders M; Ilmoniemi, Risto J; Levänen, Sari; Lin, Fa-Hsuan; May, Patrick; Melcher, Jennifer; Stufflebeam, Steven; Tiitinen, Hannu; Belliveau, John W

    2004-04-27

    Life or death in hostile environments depends crucially on one's ability to detect and gate novel sounds to awareness, such as that of a twig cracking under the paw of a stalking predator in a noisy jungle. Two distinct auditory cortex processes have been thought to underlie this phenomenon: (i) attenuation of the so-called N1 response with repeated stimulation and (ii) elicitation of a mismatch negativity response (MMN) by changes in repetitive aspects of auditory stimulation. This division has been based on previous studies suggesting that, unlike for the N1, repetitive "standard" stimuli preceding a physically different "novel" stimulus constitute a prerequisite to MMN elicitation, and that the source loci of MMN and N1 are different. Contradicting these findings, our combined electromagnetic, hemodynamic, and psychophysical data indicate that the MMN is generated as a result of differential adaptation of anterior and posterior auditory cortex N1 sources by preceding auditory stimulation. Early ( approximately 85 ms) neural activity within posterior auditory cortex is adapted as sound novelty decreases. This alters the center of gravity of electromagnetic N1 source activity, creating an illusory difference between N1 and MMN source loci when estimated by using equivalent current dipole fits. Further, our electroencephalography data show a robust MMN after a single standard event when the interval between two consecutive novel sounds is kept invariant. Our converging findings suggest that transient adaptation of feature-specific neurons within human posterior auditory cortex filters superfluous sounds from entering one's awareness.

  18. Conservative management of posterior ankle impingement: a case report

    PubMed Central

    Senécal, Isabelle; Richer, Nadia

    2016-01-01

    Objective: To describe the pain and functional improvements of a patient with posterior ankle impingement following a treatment plan incorporating soft tissue therapy, chiropractic adjustment and a progressive rehabilitation program. Clinical Features: A 37-year- old male presented with posterolateral ankle pain exacerbated by plantar flexion two weeks after sustaining an inversion ankle sprain. Oedema was present and the patient was describing a sensation of instability while walking. The initial diagnosis of lateral ankle sprain was found to be complicated by a posterior ankle impingement caused by a tenosynovitis of the flexor hallucis longus sheath suspected during the physical examination and confirmed by MRI. Intervention and Outcome: The patient was treated over a 14-week period. Soft tissue therapy, a rehabilitation program and cortisone injection were used to treat this condition. A precise description of the rehabilitation program that contains open kinetic chain, closed kinetic chain, proprioception, and conditioning exercises prescribed to the patient is given. After the treatment plan, the patient returned to play pain free and had no daily living restrictions. Summary: A protocol including rest, soft tissue therapy, open and closed kinetic chain exercises, sport-specific exercises and cortisone injection appeared to facilitate complete recovery of this patient’s posterior ankle impingement. PMID:27385836

  19. Wear of composite resins in permanent posterior teeth.

    PubMed

    Swift, E J

    1987-10-01

    Although improvements in wear resistance have accompanied the development of newer materials, the routine use of composite resins in permanent posterior teeth cannot be justified. Clinical studies have not yet proved the long-term wear resistance of these materials. However, they may be used if case selection and material selection are kept within certain guidelines. In terms of case selection, a composite resin might be used in areas of esthetic concern, or where minimal cavity preparation is possible. Resins might also be used in areas of low functional stress, and in premolars instead of molars. In selecting a material, the conventional resins should never be used for posterior teeth. Instead, a material with smaller, softer filler particles should be used. Also, light-cured materials are preferred to the self-cured types. Long-term clinical evaluation of the posterior composite resins is required before they can be accepted as a substitute for amalgam. If the problem of wear cannot be eliminated, but only reduced, then the effects of wear in terms of occlusal stability and function must be determined.

  20. Posterior segment findings in a patient with immunotactoid glomerulonephritis

    PubMed Central

    Gupta, Aditi; Prabhu, Rangarajan Venugopal; Patel, Amit K.; Sivaraj, Ramesh

    2015-01-01

    Purpose: To present a case with posterior segment findings in a patient with cloudy corneas secondary to immunotactoid glomerulonephritis (ITG). Methods: A 57-year-old female was known to have bilateral cloudy corneas diagnosed 12 years ago secondary to immunotactoid glomerulonephritis. Clinically, fundus examination was difficult to visualise due to the density of her corneal opacities. Results: B-scan ultrasound revealed significant retino-choroidal & non-inflammatory scleral thickening. The macula also showed signs of thickening in both eyes. Optical coherence tomography (OCT) showed thinning of the inner retinal layers and significant choroidal folds in both eyes. Electrodiagnostic tests (EDT) concluded loss of retinal ganglion cells with preservation of retinal function in both eyes. Conclusion: This case widens the spectrum of findings seen in patients diagnosed with Immunotactoid Glomerulonephritis and alerts us to undertake detailed posterior segment examination where possible. Ocular coherence tomography (OCT) and B-scan ultrasonography are important adjuvants to help assess the posterior segment in patients with corneal opacities secondary to ITG.

  1. The evolution of alexia and simultanagnosia in posterior cortical atrophy.

    PubMed

    Mendez, M F; Cherrier, M M

    1998-04-01

    Early alexia and higher visual impairments characterize Posterior cortical atrophy (PCA), a progressive dementing syndrome most often caused by Alzheimer disease. Posterior cortical atrophy is rare, and the nature of the visual impairments in PCA are unclear. The authors observed two patients who had an insidiously progressive reading difficulty characterized by letter-by-letter reading and otherwise intact cognitive functions. Over time, these patients developed "ventral simultanagnosia" with preserved detection of multiple stimuli but inability to interpret whole scenes. Subsequently, they progressed to Balint syndrome with "dorsal simultanagnosia," optic ataxia, and oculomotor apraxia. Structural imaging was normal, but functional imaging revealed posterior cortical dysfunction. On a letter reading task, both patients had a word superiority effect, and on a whole word reading task, they could not read most words with missing or crosshatched letters. An inability to assess whole scenes progressed to an inability to detect more than one stimulus in an array. These findings suggest an evolution of PCA with progressive difficulty in visual integration beginning with letters, progressing to whole scenes, and culminating in Balint syndrome. These changes may reflect an extension of the pathophysiology of PCA from the extrastriate visual cortex to its occipitotemporal and occipitoparietal connections. PMID:9652488

  2. Intensity-Modulated Arc Therapy for Pediatric Posterior Fossa Tumors

    SciTech Connect

    Beltran, Chris; Gray, Jonathan; Merchant, Thomas E.

    2012-02-01

    Purpose: To compare intensity-modulated arc therapy (IMAT) to noncoplanar intensity-modulated radiation therapy (IMRT) in the treatment of pediatric posterior fossa tumors. Methods and Materials: Nine pediatric patients with posterior fossa tumors, mean age 9 years (range, 6-15 years), treated using IMRT were chosen for this comparative planning study because of their tumor location. Each patient's treatment was replanned to receive 54 Gy to the planning target volume (PTV) using five different methods: eight-field noncoplanar IMRT, single coplanar IMAT, double coplanar IMAT, single noncoplanar IMAT, and double noncoplanar IMAT. For each method, the dose to 95% of the PTV was held constant, and the doses to surrounding critical structures were minimized. The different plans were compared based on conformity, total linear accelerator dose monitor units, and dose to surrounding normal tissues, including the entire body, whole brain, temporal lobes, brainstem, and cochleae. Results: The doses to the target and critical structures for the various IMAT methods were not statistically different in comparison with the noncoplanar IMRT plan, with the following exceptions: the cochlear doses were higher and whole brain dose was lower for coplanar IMAT plans; the cochleae and temporal lobe doses were lower and conformity increased for noncoplanar IMAT plans. The advantage of the noncoplanar IMAT plan was enhanced by doubling the treatment arc. Conclusion: Noncoplanar IMAT results in superior treatment plans when compared to noncoplanar IMRT for the treatment of posterior fossa tumors. IMAT should be considered alongside IMRT when treatment of this site is indicated.

  3. Anterior-posterior regionalized gene expression in the Ciona notochord

    PubMed Central

    Veeman, Michael

    2014-01-01

    Background In the simple ascidian chordate Ciona the signaling pathways and gene regulatory networks giving rise to initial notochord induction are largely understood and the mechanisms of notochord morphogenesis are being systematically elucidated. The notochord has generally been thought of as a non-compartmentalized or regionalized organ that is not finely patterned at the level of gene expression. Quantitative imaging methods have recently shown, however, that notochord cell size, shape and behavior vary consistently along the anterior-posterior (AP) axis. Results Here we screen candidate genes by whole mount in situ hybridization for potential AP asymmetry. We identify 4 genes that show non-uniform expression in the notochord. Ezrin/radixin/moesin (ERM) is expressed more strongly in the secondary notochord lineage than the primary. CTGF is expressed stochastically in a subset of notochord cells. A novel calmodulin-like gene (BCamL) is expressed more strongly at both the anterior and posterior tips of the notochord. A TGF-β ortholog is expressed in a gradient from posterior to anterior. The asymmetries in ERM, BCamL and TGF-β expression are evident even before the notochord cells have intercalated into a single-file column. Conclusions We conclude that the Ciona notochord is not a homogeneous tissue but instead shows distinct patterns of regionalized gene expression. PMID:24288133

  4. Functional unilateral posterior crossbite effects on mastication movements using axiography.

    PubMed

    Salioni, Marco Antonio Canada; Pellizoni, Silmara Elena Papa; Guimarães, Antonio Sérgio; Juliano, Yara; Alonso, Luís Garcia

    2005-05-01

    This prospective study investigated the influence of functional unilateral posterior crossbite on mastication movements. The study group included 16 patients (nine girls and seven boys) with functional unilateral posterior crossbite involving three or more posterior teeth. A control group comprised 15 individuals (nine girls and six boys) with normal occlusion and the mean age of both groups was 9.17 years. The mandibular masticatory movements were registered, using computer axiography, for 30 seconds during chewing to determine the preference side of chewing. The patterns of the first, third, and fifth chewing cycles were compared with the preference side to establish whether they would predict the chewing preference side. The extent of the maximal lateral and vertical displacements of the mandible during chewing were compared between study and control groups. This study found that overall the left side was the preferred mastication side in 43.7% of individuals in the study and 46.7% in the control group. There was no relationship between the side of the crossbite and the masticatory preference side (Mc Nemar test, P = .5). No correlation was present between the patterns of chewing movements in the first, third, or fifth cycles. Both study and control groups showed similar maximal lateral and vertical mandible displacement.

  5. Data analysis in emission tomography using emission-count posteriors

    NASA Astrophysics Data System (ADS)

    Sitek, Arkadiusz

    2012-11-01

    A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography.

  6. Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors

    PubMed Central

    Manabe, Hideki; Sumida, Tadayoshi; Tanaka, Nobuhiro; Hamasaki, Takahiko

    2015-01-01

    Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations. The posterior extradural approach is the most common; however, it remains challenging due to severe epidural veins. Although regression of pseudotumors after fusion surgery has been reported, direct decompression and a pathologic diagnosis are ideal when the pseudotumor is large. We therefore developed a new microscopic surgical technique; transdural resection. After C1 laminectomy, the dorsal and ventral dura was incised while preserving the arachnoid. Removal of the pseudotumor was performed and both of the dura were repaired. The patient’s clinical symptoms subsequently improved and the pathologic findings showed degenerative fibrocartilaginous tissue. In addition, no neurological deterioration, central spinal fluid leakage, or arachnoiditis was observed. Currently, the usefulness of the transdural approach has been reported for cervical and thoracic disk herniation. According to our results, the transdural approach is recommended for resection of retro-odontoid pseudotumors because it enables direct decompression of the spinal cord and a pathologic diagnosis. PMID:26544168

  7. A case of posterior element fracture in Kummell's disease.

    PubMed

    Kim, S W; Kim, H-S

    2012-05-01

    Kummell's disease is a rare, delayed posttraumatic collapse of a vertebral body that can occur several months or even years after an osteoporotic compression fracture. However, there are few reports of posterior element fractures associated with Kummell's disease. A 72-year-old man who had sustained an L1 osteoporotic compression fracture 14 months prior was admitted to our institution with incapacitating back pain. Plain radiographs showed progressive collapse of the L1 vertebral body and severe kyphosis at the thoracolumbar junction. Magnetic resonance imaging revealed a posterior element fracture as well as osteonecrosis of the L1 vertebral body. An L1 percutaneous vertebroplasty was performed, followed by bone cement-augmented screw fixation to maintain stability and correct the kyphotic deformity. After surgery, pain relief was immediate, and the patient was able to walk unassisted. This case illustrates that continuous axial distraction stress caused by aggravated kyphosis secondary to Kummell's disease may result in posterior element fractures. Our discussion concludes with a literature review.

  8. The effect of exercise on anterior-posterior knee laxity.

    PubMed

    Steiner, M E; Grana, W A; Chillag, K; Schelberg-Karnes, E

    1986-01-01

    A commercial knee laxity testing device was used to quantitate anterior and posterior laxity before and after exercise. Measurements were made at 20 degrees of knee flexion and with a displacement force of 133 N (30 pounds). In sedentary controls no significant change in laxity was noted over 2 hours. Squat power lifters sustained no significant change in laxity after a series of squats (0.4 to 0.7 cm) using 1.6 times body weight. However, 18% to 20% increases in mean anterior and posterior laxity were noted in college basketball players after 90 minutes of practice and in recreational runners after a 10 km race. The role of muscle relaxation in such tests was also evaluated by measuring laxity in normal knees before and during general anesthesia. Negligible laxity change was noted. Thus, functionally "complete" muscle relaxation can be obtained during testing in the cooperative individual. In conclusion, basketball players and distance runners experienced a transient increase in anterior and posterior laxity during exercise. Power lifters doing squats did not demonstrate a significant change in laxity. It appears that repetitive physiologic stresses at a high strain rate produce significant ligamentous laxity, while a relatively few large stresses at a low strain rate do not.

  9. Time-Reversal Violation

    NASA Astrophysics Data System (ADS)

    Bernabéu, José; Martínez-Vidal, Fernando

    2015-10-01

    The violation of CP symmetry between matter and antimatter in the neutral K and B meson systems is well established, with a high degree of consistency between all available experimental measurements and with the Standard Model of particle physics. On the basis of the up-to-now-unbroken CPT symmetry, the violation of CP symmetry strongly suggests that the behavior of these particles under weak interactions must also be asymmetric under time reversal T. Many searches for T violation have been performed and proposed using different observables and experimental approaches. These include T-odd observables, such as triple products in weak decays, and genuine observables, such as permanent electric dipole moments of nondegenerate stationary states and the breaking of the reciprocity relation. We discuss the conceptual basis of the required exchange of initial and final states with unstable particles, using quantum entanglement and the decay as a filtering measurement, for the case of neutral B and K mesons. Using this method, the BaBar experiment at SLAC has clearly observed T violation in B mesons.

  10. Reversible micromachining locator

    DOEpatents

    Salzer, Leander J.; Foreman, Larry R.

    1999-01-01

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved.

  11. Reversible micromachining locator

    DOEpatents

    Salzer, L.J.; Foreman, L.R.

    1999-08-31

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved. 7 figs.

  12. Time Reversal Violation

    SciTech Connect

    Quinn, H; /SLAC

    2009-01-27

    This talk briefly reviews three types of time-asymmetry in physics, which I classify as universal, macroscopic and microscopic. Most of the talk is focused on the latter, namely the violation of T-reversal invariance in particle physics theories. In sum tests of microscopic T-invariance, or observations of its violation, are limited by the fact that, while we can measure many processes, only in very few cases can we construct a matched pair of process and inverse process and observe it with sufficient sensitivity to make a test. In both the cases discussed here we can achieve an observable T violation making use of flavor tagging, and in the second case also using the quantum properties of an antisymmetric coherent state of two B mesons to construct a CP-tag. Both these tagging properties depend only on very general properties of the flavor and/or CP quantum numbers and so provide model independent tests for T-invariance violations. The microscopic laws of physics are very close to T-symmetric. There are small effects that give CP- and T-violating processes in three-generation-probing weak decays. Where a T-violating observable can be constructed we see the relationships between T-violation and CP-violation expected in a CPT conserving theory. These microscopic effects are unrelated to the 'arrow of time' that is defined by increasing entropy, or in the time direction defined by the expansion of our Universe.

  13. Reverse hierarchical PIV processing

    NASA Astrophysics Data System (ADS)

    Rohály, J.; Frigerio, F.; Hart, D. P.

    2002-07-01

    A novel hierarchical processing scheme is proposed to efficiently increase the spatial resolution and dynamic range of detecting particle image displacements in PIV images. The technique takes full advantage of the multi-resolution characteristic of the discrete correlation function by starting the processing at the smallest scale and, if necessary, gradually building correlation planes into larger interrogation areas based on the result of inter-level correlation correction and validation. It is shown that the algorithm can be implemented in both direct and FFT based correlation algorithms with greatly reduced computational complexity. The technique opens new perspectives for locally adaptive super-resolution processing taking flow field, seeding, and imaging anomalies into account. Processing at the lowest scale (e.g. pixel or particle image size) allows the combination of correlation planes on any shape. Hence the proposed reverse hierarchical processing represents interrogation area optimization both in size and shape in order to maximize the correlation plane signal-to-noise ratio. The method is successfully demonstrated on experimentally obtained images.

  14. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  15. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  16. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  17. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  18. 21 CFR 886.4392 - Nd:YAG laser for posterior capsulotomy and peripheral iridotomy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nd:YAG laser for posterior capsulotomy and...:YAG laser for posterior capsulotomy and peripheral iridotomy. (a) Identification. The Nd:YAG laser for... laser intended for disruption of the posterior capsule or the iris via optical breakdown. The...

  19. Arthroscopic posterior cruciate ligament reconstruction with allograft versus autograft

    PubMed Central

    Sun, Xiujiang; Zhang, Jianfeng; Qu, Xiaoyi

    2015-01-01

    Introduction The aim of the study was to compare and analyze retrospectively the outcomes of arthroscopic posterior cruciate ligament reconstruction with autograft versus allograft. Material and methods Seventy-one patients who underwent arthroscopic posterior cruciate ligament reconstruction with an autograft or allograft met our inclusion criteria. There were 36 patients in the autograft group and 35 patients in the allograft group. All the patients were evaluated by physical examination and a functional ligament test. Comparative analysis was done in terms of operation time, incision length, fever time, postoperative infection rate, incidence of numbness and dysesthesia around the incision, as well as a routine blood test. Results The average follow-up of the autograft group was 3.2 ±0.2 years and that of the allograft group was 3.3 ±0.6 years; there was no significant difference (p > 0.05). No differences existed in knee range of motion, Lysholm scores, International Knee Documentation Committee standard evaluation form and Tegner activity score at final follow-up (p > 0.05), except that patients in the allograft group had a shorter operation time and incision length and a longer fever time (p < 0.05). We found a difference in posterior drawer test and KT-2000 arthrometer assessment (p < 0.05). The posterior tibia displacement averaged 3.8 ±1.5 mm in the autograft group and 4.8 ±1.7 mm in the allograft group (p < 0.05). The incidence of numbness and dysesthesia around the incision in the autograft group was higher than that in the allograft group (p < 0.05). There was no infection postoperatively. The white blood cells and neutrophils in the allograft group increased more than those in the autograft group postoperatively (p < 0.05). Conclusions Both groups of patients had satisfactory outcomes after the operation. However, in the instrumented posterior laxity test, the autograft gave better results than the allograft. No differences in functional scores

  20. Reverse Transfer Project, Summer 1986.

    ERIC Educational Resources Information Center

    Reis, Elizabeth

    In 1986, a Reverse Transfer Project was initiated at Moraine Valley Community College (MVCC) in order to promote the summer school attendance at MVCC of "reverse transfer" students (i.e., students who attended another institution during the regular academic year). A mailing, containing a cover letter, informational brochure, summer catalog, and…

  1. Preference Reversal in Multiattribute Choice

    ERIC Educational Resources Information Center

    Tsetsos, Konstantinos; Usher, Marius; Chater, Nick

    2010-01-01

    A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three types of reversal effect reported in the decision-making literature, the attraction, compromise, and similarity…

  2. Classical Analog to Entanglement Reversibility

    NASA Astrophysics Data System (ADS)

    Chitambar, Eric; Fortescue, Ben; Hsieh, Min-Hsiu

    2015-08-01

    In this Letter we study the problem of secrecy reversibility. This asks when two honest parties can distill secret bits from some tripartite distribution pX Y Z and transform secret bits back into pX Y Z at equal rates using local operation and public communication. This is the classical analog to the well-studied problem of reversibly concentrating and diluting entanglement in a quantum state. We identify the structure of distributions possessing reversible secrecy when one of the honest parties holds a binary distribution, and it is possible that all reversible distributions have this form. These distributions are more general than what is obtained by simply constructing a classical analog to the family of quantum states known to have reversible entanglement. An indispensable tool used in our analysis is a conditional form of the Gács-Körner common information.

  3. The Geomagnetic Field During a Reversal

    NASA Technical Reports Server (NTRS)

    Heirtzler, James R.

    2003-01-01

    By modifying the IGRF it is possible to learn what may happen to the geomagnetic field during a geomagnetic reversal. If the entire IGRF reverses then the declination and inclination only reverse when the field strength is zero. If only the dipole component of the IGRF reverses a large geomagnetic field remains when the dipole component is zero and he direction of the field at the end of the reversal is not exactly reversed from the directions at the beginning of the reversal.

  4. Reversible Cerebral Vasoconstriction Syndrome Without Typical Thunderclap Headache.

    PubMed

    Wolff, Valérie; Ducros, Anne

    2016-04-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headache and diffuse segmental intracranial arterial constriction that resolve within three months. Stroke, which is the major complication of RCVS, can result in persistent neurological disability, and rarely causes death. Diagnosis of RCVS early in the clinical course might improve outcomes. Although recurrent thunderclap headache is the clinical hallmark of RCVS, the absence of such a pattern should not lead to discard the diagnosis. Our literature review shows that RCVS can also manifest as an unspecific headache, such as a single severe headache episode, a mild or a progressive headache. Moreover, a subset of patients with severe RCVS presents without any headache, but frequently with seizures, focal neurological deficits, confusion or coma, in the setting of stroke or posterior reversible encephalopathy syndrome. These patients may be aphasic or in comatose state, explaining their inability to give their own medical history. They may have forgotten the headache they had a few days before more dramatic symptoms, or may have a variant of the classical RCVS. By consequence, an RCVS should be suspected in patients with any unusual headache, whether thunderclap or not, and in patients with cryptogenic stroke or convexity subarachnoid hemorrhage, whether the patient also has headache or not. Diagnosis in such cases relies on the demonstration of reversible multifocal intracranial arterial stenosis and the exclusion of other causes. PMID:27016378

  5. Reversible Cerebral Vasoconstriction Syndrome Without Typical Thunderclap Headache.

    PubMed

    Wolff, Valérie; Ducros, Anne

    2016-04-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe headache and diffuse segmental intracranial arterial constriction that resolve within three months. Stroke, which is the major complication of RCVS, can result in persistent neurological disability, and rarely causes death. Diagnosis of RCVS early in the clinical course might improve outcomes. Although recurrent thunderclap headache is the clinical hallmark of RCVS, the absence of such a pattern should not lead to discard the diagnosis. Our literature review shows that RCVS can also manifest as an unspecific headache, such as a single severe headache episode, a mild or a progressive headache. Moreover, a subset of patients with severe RCVS presents without any headache, but frequently with seizures, focal neurological deficits, confusion or coma, in the setting of stroke or posterior reversible encephalopathy syndrome. These patients may be aphasic or in comatose state, explaining their inability to give their own medical history. They may have forgotten the headache they had a few days before more dramatic symptoms, or may have a variant of the classical RCVS. By consequence, an RCVS should be suspected in patients with any unusual headache, whether thunderclap or not, and in patients with cryptogenic stroke or convexity subarachnoid hemorrhage, whether the patient also has headache or not. Diagnosis in such cases relies on the demonstration of reversible multifocal intracranial arterial stenosis and the exclusion of other causes.

  6. Reverse osmosis reverses conventional wisdom with Superfund cleanup success

    SciTech Connect

    Collins, M. ); Miller, K. )

    1994-09-01

    Although widely recognized as the most efficient means of water purification, reverse osmosis has not been considered effective for remediating hazardous wastewater. Scaling and fouling, which can cause overruns and downtime, and require membrane replacement, have inhibited success in high-volume wastewater applications. Despite this background, a reverse osmosis technology developed in Europe recently was used successfully to treat large volumes of contaminated water at a major Superfund site in Texas. The technology's success there may increase the chances for reverse osmosis to find wider use in future cleanups and other waste treatment applications.

  7. Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

    PubMed

    Bufalari, Ilaria; Di Russo, Francesco; Aglioti, Salvatore Maria

    2014-07-01

    While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception. PMID:23438449

  8. Arm crossing updates brain functional connectivity of the left posterior parietal cortex

    PubMed Central

    Ora, Hiroki; Wada, Makoto; Salat, David; Kansaku, Kenji

    2016-01-01

    The unusual configuration of body parts can cause illusions. For example, when tactile stimuli are delivered to crossed arms a reversal of subjective temporal ordering occurs. Our group has previously demonstrated that arm crossing without sensory stimuli causes activity changes in the left posterior parietal cortex (PPC) and an assessment of tactile temporal order judgments (TOJs) revealed a positive association between activity in this area, especially the left intraparietal sulcus (IPS), and the degree of the crossed-hand illusion. Thus, the present study investigated how the IPS actively relates to other cortical areas under arms-crossed and -uncrossed conditions by analyzing the functional connectivity of the IPS. Regions showing connectivity with the IPS overlapped with regions within the default mode network (DMN) but the IPS also showed connectivity with other brain areas, including the frontoparietal control network (FPCN). The right middle/inferior frontal gyrus (MFG/IFG), which is included in the FPCN, showed greater connectivity in the arms-crossed condition than in the arms-uncrossed condition. These findings suggest that there is state-dependent connectivity during arm crossing, and that the left IPS may play an important role during the spatio-temporal updating of arm positions. PMID:27302746

  9. Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

    PubMed

    Bufalari, Ilaria; Di Russo, Francesco; Aglioti, Salvatore Maria

    2014-07-01

    While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception.

  10. Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues

    PubMed Central

    Leopold, David A.; Humphreys, Glyn W.; Welchman, Andrew E.

    2016-01-01

    The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269606

  11. Planning Movements in Visual and Physical Space in Monkey Posterior Parietal Cortex.

    PubMed

    Kuang, Shenbing; Morel, Pierre; Gail, Alexander

    2016-02-01

    Neurons in the posterior parietal cortex respond selectively for spatial parameters of planned goal-directed movements. Yet, it is still unclear which aspects of the movement the neurons encode: the spatial parameters of the upcoming physical movement (physical goal), or the upcoming visual limb movement (visual goal). To test this, we recorded neuronal activity from the parietal reach region while monkeys planned reaches under either normal or prism-reversed viewing conditions. We found predominant encoding of physical goals while fewer neurons were selective for visual goals during planning. In contrast, local field potentials recorded in the same brain region exhibited predominant visual goal encoding, similar to previous imaging data from humans. The visual goal encoding in individual neurons was neither related to immediate visual input nor to visual memory, but to the future visual movement. Our finding suggests that action planning in parietal cortex is not exclusively a precursor of impending physical movements, as reflected by the predominant physical goal encoding, but also contains spatial kinematic parameters of upcoming visual movement, as reflected by co-existing visual goal encoding in neuronal spiking. The co-existence of visual and physical goals adds a complementary perspective to the current understanding of parietal spatial computations in primates.

  12. Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues.

    PubMed

    Murphy, Aidan P; Leopold, David A; Humphreys, Glyn W; Welchman, Andrew E

    2016-06-19

    The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations.This article is part of the themed issue 'Vision in our three-dimensional world'. PMID:27269606

  13. Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues.

    PubMed

    Murphy, Aidan P; Leopold, David A; Humphreys, Glyn W; Welchman, Andrew E

    2016-06-19

    The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC (N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions (N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations.This article is part of the themed issue 'Vision in our three-dimensional world'.

  14. Supercritical fluid reverse micelle separation

    DOEpatents

    Fulton, John L.; Smith, Richard D.

    1993-01-01

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.

  15. Supercritical fluid reverse micelle separation

    DOEpatents

    Fulton, J.L.; Smith, R.D.

    1993-11-30

    A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.

  16. Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

    PubMed

    Yuan, Xiao-Ying; Yu, Sheng-Bo; Li, Yun-Fei; Chi, Yan-Yan; Zheng, Nan; Gao, Hai-Bin; Luan, Bing-Yi; Zhang, Zhao-Xi; Sui, Hong-Jin

    2016-03-01

    The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid. PMID:25859757

  17. Patterns of attachment of the myodural bridge by the rectus capitis posterior minor muscle.

    PubMed

    Yuan, Xiao-Ying; Yu, Sheng-Bo; Li, Yun-Fei; Chi, Yan-Yan; Zheng, Nan; Gao, Hai-Bin; Luan, Bing-Yi; Zhang, Zhao-Xi; Sui, Hong-Jin

    2016-03-01

    The myodural bridge was first described by Hack in 1995 and was thought to be related to chronic cervicogenic headaches. For a long time, few studies revealed the patterns of the myodural bridge considering the rectus capitis posterior minor muscle. In this study, P45 plastination technology and anatomical dissection were performed on head specimens, and four different terminal region types of the rectus capitis posterior minor muscle were observed, including the posterior atlanto-occipital interspace, posterior arch of the atlas and posterior atlanto-axial interspace. We propose that the myodural complex structures in the posterior atlanto-occipital and posterior atlanto-axial interspace have cooperative effects on cerebrospinal fluid and work together. This force might be an important source for the circulation of cerebrospinal fluid.

  18. Posterior shoulder instability following anatomic total shoulder arthroplasty: A case report and review of management

    PubMed Central

    Galvin, Joseph W.; Eichinger, Josef K.; Boykin, Robert E.; Szöllösy, Gregor; Lafosse, Laurent

    2015-01-01

    We report a case of posterior shoulder instability following anatomic total shoulder arthroplasty (TSA). In addition, we present guidelines to aid in the management of posterior instability after TSA. A 50-year-old male underwent anatomic TSA for glenohumeral osteoarthritis. Postoperatively, the patient developed posterior instability secondary to glenoid retroversion. He did not improve despite conservative treatment. He underwent an arthroscopic posterior bone block procedure, 4-month after his index arthroplasty. At 14-month follow-up, the patient had regained near full motion and strength, and radiographs demonstrated osseous integration with no evidence of component loosening. Posterior instability following TSA is a relatively rare complication and challenging to manage. The posterior, arthroscopic iliac crest bone block grafting procedure represents a treatment option for posterior instability in the setting of a stable glenoid prosthesis following TSA. PMID:26622130

  19. Lanczos iterated time-reversal.

    PubMed

    Oberai, Assad A; Feijóo, Gonzalo R; Barbone, Paul E

    2009-02-01

    A new iterative time-reversal algorithm capable of identifying and focusing on multiple scatterers in a relatively small number of iterations is developed. It is recognized that the traditional iterated time-reversal method is based on utilizing power iterations to determine the dominant eigenpairs of the time-reversal operator. The convergence properties of these iterations are known to be suboptimal. Motivated by this, a new method based on Lanczos iterations is developed. In several illustrative examples it is demonstrated that for the same number of transmitted and received signals, the Lanczos iterations based approach is substantially more accurate. PMID:19206835

  20. Reverse mortgage decision-making.

    PubMed

    Leviton, R

    2001-01-01

    Reverse mortgages have been suggested as a promising financial tool to help low-income older homeowners who want to remain in their houses. However, actual use of this option has been much below early estimates of potential demand. This study explored response to the new option through open-ended interviews of homeowners who had received reverse mortgage counseling. Decision-making was influenced by attachment to home, family input, and financial attitudes, including desire to leave a legacy. In general, homeowners took reverse mortgages only as a "last resort" that enabled them to maintain their independence.

  1. Multiple cytosolic calcium buffers in posterior pituitary nerve terminals.

    PubMed

    McMahon, Shane M; Chang, Che-Wei; Jackson, Meyer B

    2016-03-01

    Cytosolic Ca(2+) buffers bind to a large fraction of Ca(2+) as it enters a cell, shaping Ca(2+) signals both spatially and temporally. In this way, cytosolic Ca(2+) buffers regulate excitation-secretion coupling and short-term plasticity of release. The posterior pituitary is composed of peptidergic nerve terminals, which release oxytocin and vasopressin in response to Ca(2+) entry. Secretion of these hormones exhibits a complex dependence on the frequency and pattern of electrical activity, and the role of cytosolic Ca(2+) buffers in controlling pituitary Ca(2+) signaling is poorly understood. Here, cytosolic Ca(2+) buffers were studied with two-photon imaging in patch-clamped nerve terminals of the rat posterior pituitary. Fluorescence of the Ca(2+) indicator fluo-8 revealed stepwise increases in free Ca(2+) after a series of brief depolarizing pulses in rapid succession. These Ca(2+) increments grew larger as free Ca(2+) rose to saturate the cytosolic buffers and reduce the availability of Ca(2+) binding sites. These titration data revealed two endogenous buffers. All nerve terminals contained a buffer with a Kd of 1.5-4.7 µM, and approximately half contained an additional higher-affinity buffer with a Kd of 340 nM. Western blots identified calretinin and calbindin D28K in the posterior pituitary, and their in vitro binding properties correspond well with our fluorometric analysis. The high-affinity buffer washed out, but at a rate much slower than expected from diffusion; washout of the low-affinity buffer could not be detected. This work has revealed the functional impact of cytosolic Ca(2+) buffers in situ in nerve terminals at a new level of detail. The saturation of these cytosolic buffers will amplify Ca(2+) signals and may contribute to use-dependent facilitation of release. A difference in the buffer compositions of oxytocin and vasopressin nerve terminals could contribute to the differences in release plasticity of these two hormones.

  2. Posterior dental size reduction in hominids: the Atapuerca evidence.

    PubMed

    Bermúdez de Castro, J M; Nicolas, M E

    1995-04-01

    In order to reassess previous hypotheses concerning dental size reduction of the posterior teeth during Pleistocene human evolution, current fossil dental evidence is examined. This evidence includes the large sample of hominid teeth found in recent excavations (1984-1993) in the Sima de los Huesos Middle Pleistocene cave site of the Sierra de Atapuerca (Burgos, Spain). The lower fourth premolars and molars of the Atapuerca hominids, probably older than 300 Kyr, have dimensions similar to those of modern humans. Further, these hominids share the derived state of other features of the posterior teeth with modern humans, such as a similar relative molar size and frequent absence of the hypoconulid, thus suggesting a possible case of parallelism. We believe that dietary changes allowed size reduction of the posterior teeth during the Middle Pleistocene, and the present evidence suggests that the selective pressures that operated on the size variability of these teeth were less restrictive than what is assumed by previous models of dental reduction. Thus, the causal relationship between tooth size decrease and changes in food-preparation techniques during the Pleistocene should be reconsidered. Moreover, the present evidence indicates that the differential reduction of the molars cannot be explained in terms of restriction of available growth space. The molar crown area measurements of a modern human sample were also investigated. The results of this study, as well as previous similar analyses, suggest that a decrease of the rate of cell proliferation, which affected the later-forming crown regions to a greater extent, may be the biological process responsible for the general and differential dental size reduction that occurred during human evolution.

  3. Finding Thalamic BOLD Correlates to Posterior Alpha EEG

    PubMed Central

    Liu, Zhongming; de Zwart, Jacco A.; Yao, Bing; van Gelderen, Peter; Kuo, Li-Wei; Duyn, Jeff H.

    2012-01-01

    Oscillatory electrical brain activity in the alpha (8–13Hz) band is a prominent feature of human electroencephalography (EEG) during alert wakefulness, and is commonly thought to arise primarily from the occipital and parietal parts of the cortex. While the thalamus is considered to play a supportive role in the generation and modulation of cortical alpha rhythms, its precise function remains controversial and incompletely understood. To address this, we evaluated the correlation between the blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) signals in the thalamus and the spontaneous modulation of posterior alpha rhythms based on EEG-fMRI data acquired concurrently during an eyes-closed task-free condition. We observed both negative and positive correlations in the thalamus. The negative correlations were mostly seen within the visual thalamus, with a preference for the pulvinar over lateral geniculate nuclei. The positive correlations were found at the anterior and medial dorsal nuclei. Through functional connectivity analysis of the fMRI data, the pulvinar was found to be functionally associated with the same widespread cortical visual areas where the fMRI signals were negatively correlated with the posterior alpha modulation. In contrast, the dorsal nuclei were part of a distinct functional network that included brain stem, cingulate cortex and cerebellum. These observations are consistent with previous animal electrophysiology studies and the notion that the visual thalamus, and the pulvinar in particular, is intimately involved in the generation and spontaneous modulation of posterior alpha rhythms, facilitated by its reciprocal and widespread interaction with the cortical visual areas. We further postulate that the anterior and medial dorsal nuclei, being part of the ascending neuromodulatory system, may indirectly modulate cortical alpha rhythms by affecting vigilance and arousal level. PMID:22986355

  4. Prolapse of the posterior leaflet: resect or respect.

    PubMed

    Perier, Patrick; Hohenberger, Wolfgang; Lakew, Fitsum; Diegeler, Anno

    2015-05-01

    Prolapse of the posterior leaflet (PPL) is the most frequent dysfunction of the mitral valve in the western world. Quadrangular resection, first proposed by Alain Carpentier, has progressed to become the gold standard modality to repair posterior leaflet prolapse. Although this "resection technique" is safe, reproducible, and offers favorable long term results, it presents major drawbacks. Firstly, it leads to a reduced surface of coaptation, the ultimate goal of mitral valve repair; secondly, it does not respect the anatomy of the mitral valve; thirdly, it leads to a deformation of the base of the ventricle; and finally, degenerative disease of the mitral valve is a spectrum of lesions depending on the amount of excess tissue, and hence, a one technique-fits-all strategy cannot meet the absolute necessity to repair all mitral valve patients with PPL. Therefore, new approaches which have been proposed place greater emphasis on respecting, rather than only resecting, the leaflet tissue in order to avoid the drawbacks of the "resection" approach. The use of artificial chordae to correct the leaflet prolapse restores the normal anatomy and physiology of the mitral valve, thus producing an optimal surface of coaptation. However, this approach is limited by anatomical variances. As a community, we should expand our vision and define a clear and helpful strategy for PPL: to obtain a high, smooth and regular surface of coaptation located in the inflow of the left ventricle. To achieve this goal, it is necessary to have a high level of respect for the leaflet tissue in order to obtain the best surface of coaptation. Nonetheless, a limited resection may be needed to remodel the posterior leaflet, so that it will be smooth and regular. PMID:26309830

  5. Complications of Anterior and Posterior Cervical Spine Surgery

    PubMed Central

    Cheung, Jason Pui Yin

    2016-01-01

    Cervical spine surgery performed for the correct indications yields good results. However, surgeons need to be mindful of the many possible pitfalls. Complications may occur starting from the anaesthestic procedure and patient positioning to dura exposure and instrumentation. This review examines specific complications related to anterior and posterior cervical spine surgery, discusses their causes and considers methods to prevent or treat them. In general, avoiding complications is best achieved with meticulous preoperative analysis of the pathology, good patient selection for a specific procedure and careful execution of the surgery. Cervical spine surgery is usually effective in treating most pathologies and only a reasonable complication rate exists. PMID:27114784

  6. Osteochondroma of Maxilla Posterior Region: A Unique Case

    PubMed Central

    Singhal, Sachin; Goyal, Megha; Sharma, Bhuvnesh

    2015-01-01

    Osteochondroma is the most common benign neoplasm of the skeleton commonly affecting the long bones due to endochondral growth. In the craniofacial region this tumour is very rare. The sites of predilection are the coronoid process and the mandibular condyle. Here, we report an exceptional case of osteochondroma originating from the maxillary posterior region in a 26-year-old male patient, mimicking an odontome, not reported earlier in the literature. We also discuss the importance of various imaging modalities, most importantly, computed tomography (CT) in the evaluation of such lesions. However, histopathology remains the mainstay for definitive diagnosis in such conditions. PMID:26023654

  7. A new simplified onlay technique for posterior cruciate ligament reconstruction.

    PubMed

    Salim, Rodrigo; Fogagnolo, Fabricio; Kfuri, Mauricio

    2014-08-01

    The integrity of posterior cruciate ligament (PCL) is essential for the normal kinematics of the knee. Injury to the PCL has adverse consequences, with worsening of functional performance and an increased risk to develop osteoarthritis. Conservative treatment is sometimes adopted, not only because it is an acceptable option for selected patients but also due to the lack of consensus in the orthopedic literature regarding the best surgical method. Hereby we describe a simplified technique for onlay PCL reconstruction pointing out possible advantages if compared with the traditional transtibial or inlay techniques.

  8. Simple posterior frequency correction for vibrational spectra from molecular dynamics

    NASA Astrophysics Data System (ADS)

    Tikhonov, Denis S.

    2016-05-01

    Vibrational spectra computed from molecular dynamics simulations with large integration time steps suffer from nonphysical frequency shifts of signals [M. Praprotnik and D. Janežič, J. Chem. Phys. 122, 174103 (2005)]. A simple posterior correction technique was developed for compensation of this behavior. It performs through replacement of abscissa in the calculated spectra using following formula: ν corrected = /√{ 2 ṡ (" separators=" 1 - cos ( 2 π ṡ Δ t ṡ ν initial ) ) } 2 π ṡ Δ t , where ν are initial and corrected frequencies and Δt is the MD simulation time step. Applicability of this method was tested on gaseous infrared spectra of hydrogen fluoride and formic acid.

  9. Echocardiographic Manifestation of Esophagitis Mimicking a Posterior Mediastinal Mass

    PubMed Central

    Swarup, Supreeya; Kantamneni, Sowmya; Kabir, Sarah; Zeltser, Roman; Makaryus, Amgad N

    2014-01-01

    Incidental extracardiac findings (ECFs) are commonly noted on cardiac imaging. The majority of the ECFs are noticed on computed tomography (CT), cardiac magnetic resonance scanning, and myocardial perfusion imaging. Although transthoracic echocardiography (TTE) is a widely used cardiac modality, there is scarcity of data describing ECF on TTE. ECFs have the potential to alter patient management. We present a rare case of a cystic mass seen in the posterior mediastinum on TTE, which led to further evaluation and diagnosis of esophagitis with ulceration. PMID:25780343

  10. Current approach in the diagnosis and management of posterior uveitis

    PubMed Central

    Sudharshan, S; Ganesh, Sudha K; Biswas, Jyotrimay

    2010-01-01

    Posterior uveitic entities are varied entities that are infective or non-infective in etiology. They can affect the adjacent structures such as the retina, vitreous, optic nerve head and retinal blood vessels. Thorough clinical evaluation gives a clue to the diagnosis while ancillary investigations and laboratory tests assist in confirming the diagnosis. Newer evolving techniques in the investigations and management have increased the diagnostic yield. In case of diagnostic dilemma, intraocular fluid evaluation for polymerase chain testing for the genome and antibody testing against the causative agent provide greater diagnostic ability. PMID:20029144

  11. An esthetic, bonded inlay/onlay technique for posterior teeth.

    PubMed

    Jackson, R D; Ferguson, R W

    1990-01-01

    In the past, the primary focus of dentistry has been on the alleviation of pain and stopping the progression of disease. The reduction in the prevalence of dental caries, along with advances in adhesive technology, have combined to revolutionize the practice of dentistry today. The modern dentist, using the latest available cosmetic techniques, is now able to satisfy the emotional wants and needs of patients. The public, well informed about the possibilities for anterior esthetics, now desire tooth-colored restorations in the posterior. A new heat- and pressure-curing resin inlay/onlay material and the clinical and laboratory technique for its use are discussed.

  12. Clipping of ipsilateral posterior communicating and superior cerebellar artery aneurysms.

    PubMed

    Welch, Babu G

    2015-01-01

    The case is a 55-year-old female who presented with dizziness as the chief complaint. She has a family history of two relatives with subarachnoid hemorrhage. Digital subtraction angiography revealed the presence of a left-sided posterior communicating artery aneurysm and an ipsilateral superior cerebellar artery (SCA) aneurysm. Due to the smaller nature of the SCA, a decision was made to proceed with surgical clipping of both lesions through a pterional approach. A narrated video with illustrations depicts the intraoperative management of these lesions with postoperative angiography results. The video can be found here: http://youtu.be/HCHToSsXv-4 . PMID:25554845

  13. Endovascular coil embolization of unruptured posterior communicating artery aneurysm.

    PubMed

    Binning, Mandy; Hakma, Zakaria; Veznedaroglu, Erol

    2014-07-01

    The patient is a 60-year-old woman who presented to her primary care physician with new onset of headache. She was neurologically intact without cranial nerve deficit. An outpatient CT angiogram (CTA) revealed no subarachnoid hemorrhage, but showed a right-sided posterior communicating artery aneurysm measuring 11 mm by 10 mm. Digitally subtracted cerebral angiography confirmed these measurements and showed that the aneurysm was amenable to endovascular coil embolization. The patient underwent aneurysm coiling without complication and was discharged to home on postoperative Day 1. The video can be found here: http://youtu.be/MjOc3Zpv2K8 . PMID:24983726

  14. The chemotherapy of posterior fossa tumors in childhood.

    PubMed

    Friedman, H S; Oakes, W J

    1987-01-01

    Conventional therapy for brain tumors, consisting of neurosurgical intervention and radiotherapy, has not resulted in the successes achievable in other childhood malignancies. The role of adjuvant chemotherapy, well defined in many childhood cancers, has not yet contributed significantly to the treatment of children with brain tumors. Chemotherapy of recurrent tumors has produced regressions but no cures. The most active agents identified to date in the treatment of recurrent posterior fossa tumors include cisplatinum, cyclophosphamide and methotrexate. Future efforts will need to focus on the rational selection of drugs for study in limited agent histology-stratified phase II trials, with advancement of active agents into large randomized phase III adjuvant therapy trials.

  15. Conservative indirect restorations for posterior teeth. Cast versus bonded ceramic.

    PubMed

    Donovan, T E; Chee, W W

    1993-07-01

    The practitioner today has a number of alternative restorative modalities from which to chose when faced with the necessity of restoring posterior teeth. The primary options with extensively broken down posterior teeth are cast gold and bonded ceramic inlays, onlays, and partial veneer restorations. The dentist and informed patient should make the choice of which modality is appropriate based on a number of criteria. Certainly, based on the criteria of basic physical properties, potential for marginal integrity and stability of that integrity, cast gold is the material of choice. In terms of conservation of tooth structure and systemic biocompatibility, both restoration types are excellent. With regard to effects on long-term pulpal health, much remains unknown with many of the materials used with bonded restorations at the present time. Conservative cast gold restorations have proved to be very successful in this regard over the long term. The potential for tooth strengthening with bonded restorations is certainly an exciting, but as yet, unproven, clinical reality. Thus, until those clinical data are available, the most predictable means of restoration of extensively broken down posterior teeth is with partial-coverage cast gold, protecting cusps at risk as required (Fig. 9). As mentioned previously, cast gold inlays are also a very conservative and predictable restoration (Fig. 10). Both cast gold and bonded ceramic restorations are technically demanding, but the details required to produce excellent gold castings are well defined, and can be learned readily. Much remains to be learned regarding the materials and the techniques used to fabricate bonded ceramic restorations. Priority issues would seem to be reaching a consensus regarding the details of tooth preparation and the development of improved luting resins with improved wear resistance. Simplified techniques to improve the quality of the fit of these types of restoration also are of paramount importance

  16. Considerations for ceramic inlays in posterior teeth: a review

    PubMed Central

    Hopp, Christa D; Land, Martin F

    2013-01-01

    This review of ceramic inlays in posterior teeth includes a review of the history of ceramic restorations, followed by common indications and contraindications for their use. A discussion on the potential for tooth wear is followed by a review of recommended preparation design considerations, fabrication methods, and material choices. Despite the improved materials available for fabrication of porcelain inlays, fracture remains a primary mode of inlay failure. Therefore, a brief discussion on strengthening methods for ceramics is included. The review concludes with a section on luting considerations, and offers the clinician specific recommendations for luting procedures. In conclusion, inlay success rates and longevity, as reported in the literature, are summarized. PMID:23750101

  17. The use and abuse of aesthetic materials in posterior teeth.

    PubMed

    Mitchem, J C

    1988-06-01

    This paper summarizes the clinically significant concerns surrounding the use of aesthetic restoratives in posterior teeth. Composite resins are far from ideal and possess some properties that should be of real concern to the dentist. They are not amalgam substitutes. On the other hand, they do have a place in the conservative cavity where aesthetics are desired. The suggested use of composite and porcelain inlays or onlays is an attempt to circumvent some of the concerns generated by the routine use of composites. However, the relative scarcity of clinical studies suggests a limited usage at this time.

  18. Posterior cingulate cortex: adapting behavior to a changing world.

    PubMed

    Pearson, John M; Heilbronner, Sarah R; Barack, David L; Hayden, Benjamin Y; Platt, Michael L

    2011-04-01

    When has the world changed enough to warrant a new approach? The answer depends on current needs, behavioral flexibility and prior knowledge about the environment. Formal approaches solve the problem by integrating the recent history of rewards, errors, uncertainty and context via Bayesian inference to detect changes in the world and alter behavioral policy. Neuronal activity in posterior cingulate cortex - a key node in the default network - is known to vary with learning, memory, reward and task engagement. We propose that these modulations reflect the underlying process of change detection and motivate subsequent shifts in behavior.

  19. Posterior bilateral condylar displacement: its diagnosis and treatment.

    PubMed

    Weinberg, L A

    1976-10-01

    One type of condylar displacement (posterior bilateral) was discussed as an etiologic factor in TMJ dysfunction. Joint noise, tenderness on muscle palpation, and acute TMJ pain are all considered signs of TMJ dysfunction. Any joint noise is considered to be an early dysfunctional symptom because of its higher incidence in association with palpable muscle pain or acute TMJ dysfunction. Sometimes the joint noise will immediately precede acute muscle pain and/or fluctuate with the painful symptoms. The treatment of bilateral posterior condyle displacement has been described. The mandibular anterior teeth were shortened and the maxillary posterior occlusion adjusted so that the mandible could be respositioned in an anterior position without increasing the vertical dimension of occlusion. A silver-plated maxillary cast was obtained and mounted on a semiadjustable articulator (Hanau) with a face-bow. The mandibular cast was mounted in the dysfunctional (retruded) centric relation. The articulator was moved into a protrusive position by the amount of anterior correction that is needed to reposition the condyles into the middle of the fossae symmetrically on both sides. The original TMJ radiographs provide the necessary information for this clinical judgment. Acrylic resin was placed in the space created between the condylar sphere and stop on the articulator. An acrylic resin temporary repositioning prosthesis constructed on the metal cast has two functions. It provides a therapeutic trial for the anterior condylar respositioning, and it holds the mandible in the therapeutic position while TMJ radiographs confirm the corrective position of the condyles in the fossae. After a successful 6 to 8 week trial period with remission of symptoms, a gold prosthesis was constructed on the same cast in the same therapeutic position. It remains to be seen whether, after several years, the condylar suspension system changes from a dysfunctional centric relation to a new functional

  20. Surgical treatment of arteriovenous malformations of the posterior fossa.

    PubMed

    Viale, G L; Pau, A; Viale, E S

    1979-11-01

    Nine cases of arteriovenous malformations of the posterior fossa were operated upon, using microsurgical techniques. The excision was radical in eight patients. Seven of them, as well as the sole patient who had a partial removal of the malformation, returned to their previous occupations without neurological signs. In one case the preoperative deficit was unchanged. Some lesions that appear to penetrate the brain stem actually lie on its surface and can be dissected through an extrapial plane of cleavage. Extension of the malformation into the cerebellar peduncles requires dissection of the tangle and opening of the IVth ventricle.

  1. Connectivity between ventromedial prefrontal cortex and posterior superior temporal sulcus.

    PubMed

    Vallesi, Antonino

    2016-01-01

    The well-articulated Self Attention Network (SAN) framework accounts for a great portion of the available evidence on neurocognitive interactions between self-bias phenomena and attention. I argue that more work is necessary to refine our understanding about the effective and functional connectivity of the different nodes of the proposed network. In particular, the nature of the control of ventro-medial prefrontal cortex over posterior superior temporal sulcus has to be worked out further. Simple excitatory connections between these two nodes, as proposed by the SAN model, do not satisfactorily account for existing neuropsychological dissociations and are not fully warranted by neuroimaging evidence. PMID:26273997

  2. Foraminotomia cervical posterior en el tratamiento de conflictos foraminales

    PubMed Central

    Campero, Álvaro; Barrera, Ramiro; Ajler, Pablo

    2012-01-01

    Introducción: La foraminomotima cervical posterior es un procedimiento utilizado para la descompresion radicular por via posterior y constituye una alternativa a la via clásica anterior. En este trabajo evaluamos nuestra serie de pacientes tratados por esta via. Método: Desde enero de 2008 a diciembre de 2011, 17 pacientes (18 foraminotomías) fueron operados por presentar cervicobraquialgia a causa de un conflicto foraminal, realizando un foraminotomía cervical posterior. Los pacientes fueron evaluados en el postoperatorio inmediato, al mes y a los 3 meses de la cirugía. Los parámetros para valorar los resultados fueron la Escala Análoga del Dolor (VAS), la Neck Disability Index y los criterios de Odom. Resultados: El dolor radicular por conflicto foraminal secundario a hernia de disco cervical fue el síntoma y la patología predominante. El nivel más afectado fue C5-C6. La resolución completa del dolor radicular se observó en casi todos los pacientes. La VAS preoperatoria en promedio fue de 8.8 (mínimo 8 – máximo 10), con una franca mejoría en todos los casos (0.4 en el último control). La media en la Neck Disability Index al inicio fue de 35.3 (mínimo 32 – máximo 45), con una evolución favorable en la evaluación final (0.6). Los Criterios de Odom para la evaluación de pacientes operados de columna cervical fueron satisfactorios con un promedio de 1.17. Se observaron complicaciones en 4 pacientes (23%), todas tuvieron una evolución favorable. No hubo infecciones, discitis ni empeoramiento de los síntomas preexistentes en ningún paciente. Conclusión: La foraminotomía cervical posterior es un procedimiento efectivo para el tratamiento del dolor radicular en los conflictos foraminales PMID:23596556

  3. Diagnostic pitfalls: posterior ischemic optic neuropathy mimicking optic neuritis.

    PubMed

    Lysandropoulos, Andreas P; Carota, Antonio

    2011-02-01

    In young people, the most frequent cause of isolated monocular visual loss due to an optic neuropathy is optic neuritis. We present the case of a 27 year old woman who presented monocular visual loss, excruciating orbital pain and unusual temporal headache. The initial diagnosis of optic neuritis revealed later to be a posterior ischemic optic neuropathy (PION). In this case, PION was the first unique presentation of a non-traumatic carotid dissection, and it was followed 24h later by an ischemic stroke. Sudden monocular visual loss associated with a new-onset headache are clinical symptoms that should immediately prompt to a carotid dissection. PMID:21056537

  4. Mesh erosion after laparoscopic posterior rectopexy: A rare complication

    PubMed Central

    Mathew, Mittu J; Parmar, Amit K; Reddy, Prasanna K

    2014-01-01

    Laparoscopic posterior mesh rectopexy (LPMR) is now an accepted surgical treatment for complete rectal prolapse. It is associated with complications such as partial mucosal prolapse, fecal impaction, constipation, and rarely recurrence. Erosion of the mesh into the rectum after LPMR is very rare. We report herein the case of 40-year-old man who presented with mesh erosion into the rectum and managed successfully by the laparoscopic excision of mesh. This is probably the first such case managed by the laparoscopic approach. PMID:24501509

  5. Arthroscopic Management of Anterior, Posterior, and Multidirectional Shoulder Instabilities.

    PubMed

    Field, Larry D; Ryu, Richard K N; Abrams, Jeffrey S; Provencher, Matthew

    2016-01-01

    Arthroscopic shoulder stabilization offers several potential advantages compared with open surgery, including the opportunity to more accurately evaluate the glenohumeral joint at the time of diagnostic assessment; comprehensively address multiple pathologic lesions that may be identified; and avoid potential complications unique to open stabilization, such as postoperative subscapularis failure. A thorough understanding of normal shoulder anatomy and biomechanics, along with the pathoanatomy responsible for anterior, posterior, and multidirectional shoulder instability patterns, is very important in the management of patients who have shoulder instability. The treating physician also must be familiar with diagnostic imaging and physical examination maneuvers that are required to accurately diagnose shoulder instability.

  6. Posterior dislocation of the sternoclavicular joint leading to mediastinal compression.

    PubMed

    Jougon, J B; Lepront, D J; Dromer, C E

    1996-02-01

    Dislocations of the sternoclavicular joint are uncommon, and the posterior variety have a potential for considerable morbidity. We report a case with compression of the vital structures within the superior mediastinum. It was a rugby player getting run over by the scrum. The mechanism was an indirect force exerted forward and laterally against the shoulder. The patient complained of pain and dysphagia. A systolic right cervical murmur was heard. Angiography was normal and esophagography showed extrinsic esophageal compression. Surgical reduction was performed because there was a slight pneumomediastinum on the computed tomography. This case report demonstrates the mechanism, complications, and treatment of such a lesion. PMID:8572795

  7. Isolated posterior malleolus fracture: a rare injury mechanism

    PubMed Central

    Serbest, Sancar; Tiftikçi, Uğur; Tosun, Haci Bayram; Kesgin, Engin; Karataş, Metin

    2015-01-01

    Sprain of the ankle is undoubtedly a common injury during athletic activity, and the sprain can be also associated with fracture of the ankle. Isolated posterior malleolus fracture is a very rare condition, which is usually missed. Here, we are presenting a 37 years old female patient, who suffered injury secondary pressing on brake pedal during collision in a traffic accident. Clinical evaluation is based on Ottawa Ankle Rules and a fracture is diagnosed; patient is started on daily activities at postoperative Week 8. This study aims to emphasize that Ottawa Ankle Rules are usually efficient for evaluating fractures of ankle, but clinicians should always make a detailed physical examination. PMID:26097627

  8. Considerations for ceramic inlays in posterior teeth: a review.

    PubMed

    Hopp, Christa D; Land, Martin F

    2013-01-01

    This review of ceramic inlays in posterior teeth includes a review of the history of ceramic restorations, followed by common indications and contraindications for their use. A discussion on the potential for tooth wear is followed by a review of recommended preparation design considerations, fabrication methods, and material choices. Despite the improved materials available for fabrication of porcelain inlays, fracture remains a primary mode of inlay failure. Therefore, a brief discussion on strengthening methods for ceramics is included. The review concludes with a section on luting considerations, and offers the clinician specific recommendations for luting procedures. In conclusion, inlay success rates and longevity, as reported in the literature, are summarized.

  9. Reverse Discrimination and Aggressive Behavior.

    ERIC Educational Resources Information Center

    Johnson, Stephen D.

    1980-01-01

    White subjects were aggressive toward Black opponents when contest results appeared to reflect elements of reverse discrimination; but they showed less aggressive behavior toward Black opponents when they thought their loss was due to their opponents' superior ability. (RL)

  10. Deciphering records of geomagnetic reversals

    NASA Astrophysics Data System (ADS)

    Valet, Jean-Pierre; Fournier, Alexandre

    2016-06-01

    Polarity reversals of the geomagnetic field are a major feature of the Earth's dynamo. Questions remain regarding the dynamical processes that give rise to reversals and the properties of the geomagnetic field during a polarity transition. A large number of paleomagnetic reversal records have been acquired during the past 50 years in order to better constrain the structure and geometry of the transitional field. In addition, over the past two decades, numerical dynamo simulations have also provided insights into the reversal mechanism. Yet despite the large paleomagnetic database, controversial interpretations of records of the transitional field persist; they result from two characteristics inherent to all reversals, both of which are detrimental to an ambiguous analysis. On the one hand, the reversal process is rapid and requires adequate temporal resolution. On the other hand, weak field intensities during a reversal can affect the fidelity of magnetic recording in sedimentary records. This paper is aimed at reviewing critically the main reversal features derived from paleomagnetic records and at analyzing some of these features in light of numerical simulations. We discuss in detail the fidelity of the signal extracted from paleomagnetic records and pay special attention to their resolution with respect to the timing and mechanisms involved in the magnetization process. Records from marine sediments dominate the database. They give rise to transitional field models that often lead to overinterpret the data. Consequently, we attempt to separate robust results (and their subsequent interpretations) from those that do not stand on a strong observational footing. Finally, we discuss new avenues that should favor progress to better characterize and understand transitional field behavior.

  11. Reverse Current in Solar Flares

    NASA Technical Reports Server (NTRS)

    Knight, J. W., III

    1978-01-01

    An idealized steady state model of a stream of energetic electrons neutralized by a reverse current in the pre-flare solar plasma was developed. These calculations indicate that, in some cases, a significant fraction of the beam energy may be dissipated by the reverse current. Joule heating by the reverse current is a more effective mechanism for heating the plasma than collisional losses from the energetic electrons because the Ohmic losses are caused by thermal electrons in the reverse current which have much shorter mean free paths than the energetic electrons. The heating due to reverse currents is calculated for two injected energetic electron fluxes. For the smaller injected flux, the temperature of the coronal plasma is raised by about a factor of two. The larger flux causes the reverse current drift velocity to exceed the critical velocity for the onset of ion cyclotron turbulence, producing anomalous resistivity and an order of magnitude increase in the temperature. The heating is so rapid that the lack of ionization equilibrium may produce a soft X-ray and EUV pulse from the corona.

  12. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... This test may be scheduled as part of the endurance run. (b) 175 reversals must be made from flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff...

  13. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... This test may be scheduled as part of the endurance run. (b) 175 reversals must be made from flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff...

  14. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... This test may be scheduled as part of the endurance run. (b) 175 reversals must be made from flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff...

  15. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... This test may be scheduled as part of the endurance run. (b) 175 reversals must be made from flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff...

  16. REHABILITATION PROTOCOL AFTER ISOLATED POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    de Paula Leite Cury, Ricardo; Kiyomoto, Henry Dan; Rosal, Gustavo Fogolin; Bryk, Flávio Fernandes; de Oliveira, Victor Marques; de Camargo, Osmar Pedro Arbix

    2015-01-01

    To create a rehabilitation protocol following reconstruction of the posterior cruciate ligament (PCL), through a literature review. The literature review was conducted in the Medline and Embase databases, to search for data on biomechanical concepts and analyses relating to the posterior cruciate ligament of the knee. The search strategy was set up using the following rules: problem or injury in association with anatomical location terms; or surgical intervention procedure in association with rehabilitation terms. We began the process in this manner and subsequently introduced restrictions on certain terms to improve the search specificity. To design the protocol, a table was created for better data assessment, based on the time that elapsed between surgery and the start of physiotherapy. A rehabilitation protocol was created to improve weight-bearing control in the initial weeks after surgery, with the aid of a knee brace. Our aim was to achieve gains in total range of motion of the knee, which should be attained by the third month, thereby avoiding contractures resulting from the tissue healing process. Strengthening exercises and sensory-motor training were guided accordingly, thus avoiding overload on the graft and respecting the healing phases. The protocol proposed through this review was based on the current evidence relating to this subject. PMID:27047844

  17. A Generalized, Likelihood-Free Method for Posterior Estimation

    PubMed Central

    Turner, Brandon M.; Sederberg, Per B.

    2014-01-01

    Recent advancements in Bayesian modeling have allowed for likelihood-free posterior estimation. Such estimation techniques are crucial to the understanding of simulation-based models, whose likelihood functions may be difficult or even impossible to derive. However, current approaches are limited by their dependence on sufficient statistics and/or tolerance thresholds. In this article, we provide a new approach that requires no summary statistics, error terms, or thresholds, and is generalizable to all models in psychology that can be simulated. We use our algorithm to fit a variety of cognitive models with known likelihood functions to ensure the accuracy of our approach. We then apply our method to two real-world examples to illustrate the types of complex problems our method solves. In the first example, we fit an error-correcting criterion model of signal detection, whose criterion dynamically adjusts after every trial. We then fit two models of choice response time to experimental data: the Linear Ballistic Accumulator model, which has a known likelihood, and the Leaky Competing Accumulator model whose likelihood is intractable. The estimated posterior distributions of the two models allow for direct parameter interpretation and model comparison by means of conventional Bayesian statistics – a feat that was not previously possible. PMID:24258272

  18. REHABILITATION PROTOCOL AFTER ISOLATED POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION.

    PubMed

    de Paula Leite Cury, Ricardo; Kiyomoto, Henry Dan; Rosal, Gustavo Fogolin; Bryk, Flávio Fernandes; de Oliveira, Victor Marques; de Camargo, Osmar Pedro Arbix

    2012-01-01

    To create a rehabilitation protocol following reconstruction of the posterior cruciate ligament (PCL), through a literature review. The literature review was conducted in the Medline and Embase databases, to search for data on biomechanical concepts and analyses relating to the posterior cruciate ligament of the knee. The search strategy was set up using the following rules: problem or injury in association with anatomical location terms; or surgical intervention procedure in association with rehabilitation terms. We began the process in this manner and subsequently introduced restrictions on certain terms to improve the search specificity. To design the protocol, a table was created for better data assessment, based on the time that elapsed between surgery and the start of physiotherapy. A rehabilitation protocol was created to improve weight-bearing control in the initial weeks after surgery, with the aid of a knee brace. Our aim was to achieve gains in total range of motion of the knee, which should be attained by the third month, thereby avoiding contractures resulting from the tissue healing process. Strengthening exercises and sensory-motor training were guided accordingly, thus avoiding overload on the graft and respecting the healing phases. The protocol proposed through this review was based on the current evidence relating to this subject.

  19. Posterior Iris Fixated Intraocular Lens for Pediatric Traumatic Cataract

    PubMed Central

    Kavitha, V.; Balasubramanian, Preethi; Heralgi, Mallikarjun M.

    2016-01-01

    Purpose: To evaluate the postoperative visual outcomes and complications of posterior iris fixated intraocular lens (IFIOL) implantation for pediatric traumatic cataract. Methods: A retrospective clinical audit was performed of all the pediatric traumatic cataract patients who underwent lens removal and iris fixated lens implantation due to inadequate capsular support with or without corneal tear repair between January 2009 and December 2013. Data were collected and analyzed on the preoperative and postoperative visual outcomes and complications. Results: Twenty-five children (25 eyes; 21 males and 4 females) were enrolled with the mean age of 11 ± 4.0 years. There were 72% of eyes that underwent primary cataract removal with IFIOL implantation. Twenty-eight percent of eyes underwent corneal tear repair prior to intraocular lens (IOL) implantation. Preoperative best corrected visual acuity (BCVA) was hand motion in 32% eyes, counting fingers in 24%, and perception of light in 44%. Postoperative BCVA of 0-0.2 logarithm of minimum angle of resolution was reported in the 64% of eyes. One eye developed secondary glaucoma, one eye underwent re-enclavation, and none developed retinal complications. Conclusion: Posterior IFIOL implantation resulted in an improved visual outcome, low incidence of postoperative complications, and is a good alternative to other IOL, in the cases of pediatric traumatic cataract without adequate capsular support. PMID:27162456

  20. Vestibular and visual responses in human posterior insular cortex.

    PubMed

    Frank, Sebastian M; Baumann, Oliver; Mattingley, Jason B; Greenlee, Mark W

    2014-11-15

    The central hub of the cortical vestibular network in humans is likely localized in the region of posterior lateral sulcus. An area characterized by responsiveness to visual motion has previously been described at a similar location and named posterior insular cortex (PIC). Currently it is not known whether PIC processes vestibular information as well. We localized PIC using visual motion stimulation in functional magnetic resonance imaging (fMRI) and investigated whether PIC also responds to vestibular stimuli. To this end, we designed an MRI-compatible caloric stimulation device that allowed us to stimulate bithermally with hot temperature in one ear and simultaneously cold temperature in the other or with warm temperatures in both ears for baseline. During each trial, participants indicated the presence or absence of self-motion sensations. We found activation in PIC during periods of self motion when vestibular stimulation was carried out with minimal visual input. In combined visual-vestibular stimulation area PIC was activated in a similar fashion during congruent and incongruent stimulation conditions. Our results show that PIC not only responds to visual motion but also to vestibular stimuli related to the sensation of self motion. We suggest that PIC is part of the cortical vestibular network and plays a role in the integration of visual and vestibular stimuli for the perception of self motion.

  1. Case report of a dilated odontome in the posterior mandible

    PubMed Central

    Almeida, Bruno; Silva, António; Pereira, Miguel; Silva, Mariana; Nunes, Stephanie

    2016-01-01

    Introduction Dens invaginatus (dens in dente) is a developmental malformation resulting from an invagination of enamel organ into the dental papilla, beginning at the crown and sometimes extending into the root before calcification occurs. Dilated odontome is the most extreme form of dens invaginatus and it is extremely rare in the posterior mandible. Presentation of case A 47 years old female patient with occasional episodes of diffuse pain and discomfort in the left posterior mandibular region. The extra-oral examination showed slight facial asymmetry. Panoramic and intra-oral X-rays show an intraosseous circular formation with radiopaque external limits and radiolucent interior. Discussion Computerized tomography scan reveals the bone integrity around the formation, as well as the independence of the neuro-vascular structures of the region. The most likely diagnostic option was dilated odontome. The enucleation procedure was carried out, and the fragments were sent to histopathological examination that revealed a diagnosis consistent with a dilated odontome. Conclusion In this case, the conservative surgical approach after planning was effective and predictable in the treatment of the pathology and patient symptoms without major complications. PMID:26780470

  2. Human posterior parietal cortex mediates hand-specific planning

    PubMed Central

    Valyear, Kenneth F.; Frey, Scott H.

    2015-01-01

    The processes underlying action planning are fundamental to adaptive behavior and can be influenced by recent motor experience. Here, we used a novel fMRI Repetition Suppression (RS) design to test the hypotheses that action planning unfolds more efficiently for successive actions made with the same hand. More efficient processing was predicted to correspond with both faster response times (RTs) to initiate actions and reduced fMRI activity levels – RS. Consistent with these predictions, we detected faster RTs for actions made with the same hand and accompanying fMRI-RS within bilateral posterior parietal cortex and right-lateralized parietal operculum. Within posterior parietal cortex, these RS effects were localized to intraparietal and superior parietal cortices. These same areas were more strongly activated for actions involving the contralateral hand. The findings provide compelling new evidence for the specification of action plans in hand-specific terms, and indicate that these processes are sensitive to recent motor history. Consistent with computational efficiency accounts of motor history effects, the findings are interpreted as evidence for comparatively more efficient processing underlying action planning when successive actions involve the same versus opposite hand. PMID:25842294

  3. The right posterior paravermis and the control of language interference.

    PubMed

    Filippi, Roberto; Richardson, Fiona M; Dick, Frederic; Leech, Robert; Green, David W; Thomas, Michael S C; Price, Cathy J

    2011-07-20

    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions in which brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum in which gray matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity, with the lower part of the cerebellum being the region most likely to be excluded.

  4. Posterior foss avenous angiomas with drainage through the brain stem

    SciTech Connect

    Damiano, T.R.; Truwit, C.L. ); Dowd, C.F. ); Symonds, D.L. )

    1994-04-01

    To describe 11 cases of posterior fossa venous angiomas with drainage through the brain stem. Eleven cases of posterior fossa venous angioma with drainage through the brain stem were evaluated using MR. Correlation with known routes of venous drainage for the cerebellum and brain stem is made. Six of the 11 venous angiomas were found in the cerebellum, four in the brain stem; one involved both the cerebellum and brain stem. The cerebellar venous angiomas drained to subependymal veins about the fourth ventricle and dorsal pons. These then connected with an enlarged transmesencephalic or transpontine vein, to drain anteriorly to the anterior pontine veins. The brain stem angiomas had variable drainage depending on location. Evidence of hemorrhage was seen in five cases. Cerebellar and brain stem venous angiomas have several potential routes of drainage, including an enlarged vein traversing the pons, midbrain, or medulla. A knowledge of the normal venous anatomy of this region helps to understand the occurrence of these uncommon routes of venous drainage. 15 refs., 8 figs., 1 tab.

  5. Patient risk factors' influence on survival of posterior composites.

    PubMed

    van de Sande, F H; Opdam, N J; Rodolpho, P A Da Rosa; Correa, M B; Demarco, F F; Cenci, M S

    2013-07-01

    This practice-based retrospective study evaluated the survival of resin composite restorations in posterior teeth, focusing on the influence of potential patient risk factors. In total, 306 posterior composite restorations placed in 44 adult patients were investigated after 10 to 18 yrs. The history of each restoration was extracted from the dental records, and a clinical evaluation was performed with those still in situ. The patient risk status was assessed for caries and "occlusal-stress" (bruxism-related). Statistical analysis was performed by the Kaplan-Meier method and Cox-regression multivariate analysis. In total, 30% of the restorations failed, of which 82% were found in patients with 1 or 2 risk factors. Secondary caries was the main reason of failure within caries-risk patients, whereas fracture was the main reason in "occlusal-stress-risk" patients. The patient variables gender and age did not significantly affect survival, but risk did (p < .001). Tooth type (p < .001), arch (p = .013), and pulpal vitality (p = .003) significantly affected restoration survival. Within the limits of this retrospective evaluation, the survival of restorations is affected by patient risk factors, which should be included in survival analyses of restorations.

  6. Advances in Drug Delivery to the Posterior Segment

    PubMed Central

    Pearce, William; Hsu, Jason; Yeh, Steven

    2015-01-01

    Purpose Emerging developments and research for drug delivery to the posterior segment offer a promising future for the treatment of vitreoretinal disease. As new technologies enter the market, clinicians should be aware of new indications and ongoing clinical trials. Recent Findings This review summarizes the advantages and shortcomings of the most commonly used drug delivery methods including vitreous dynamics, physician sustainability and patient preferences. Currently available intravitreal corticosteroid-release devices offer surgical and in-office management of retinal vascular disease and posterior uveitis. The suprachoroidal space offers a new anatomic location for the delivery of lower dose medications directly to the target tissue. Implantable drug reservoirs would potentially allow for less frequent intravitreal injections reducing treatment burdens and associated risks. Newer innovations in encapsulated cell technology offer promising results in early clinical trials. Summary While pars plana intravitreal injection remains the mainstay of therapy for many vitreoretinal diseases, targeted delivery and implantable eluting devices are rapidly demonstrating safety and efficacy. These therapeutic modalities offer promising options for the vitreoretinal therapeutic landscape. PMID:25759965

  7. Cortical blindness following posterior lumbar decompression and fusion.

    PubMed

    Agarwal, Nitin; Hansberry, David R; Goldstein, Ira M

    2014-01-01

    Perioperative vision loss following non-ocular surgery is a well-documented phenomenon. In particular, perioperative vision loss has been frequently cited following spinal surgery. Although the rate of vision compromise in spinal surgery is relatively low, the consequences can be quite severe and devastating for the patient. We report a 60-year-old woman who initially presented with back and left leg pain as well as paraparesis. Imaging studies of the lumbar spine showed bony erosion consistent with tumor infiltration of the L3 and L4 spinal segments. Laminectomy at the L2-L4 levels for decompression of the intraspinal tumor was performed. Pathology of the resected bone was consistent with metastatic adenocarincoma. Postoperatively, the patient suffered severe anemia and bilateral infarctions of the posterior cerebral arteries and occipital lobes resulting in vision compromise. Although a definitive pathogenesis remains unknown, preoperative cardiovascular issues and intraoperative hemodynamic instabilities have typically been implicated as high risk factors. High risk factors for this novel clinical presentation of visual compromise following posterior lumbar laminectomy with decompression for an intraspinal tumor are reported. PMID:23791834

  8. Developmental origin of the posterior pigmented epithelium of iris.

    PubMed

    Wang, Xiaobing; Xiong, Kai; Lu, Lei; Gu, Dandan; Wang, Songtao; Chen, Jing; Xiao, Honglei; Zhou, Guomin

    2015-03-01

    Iris epithelium is a double-layered pigmented cuboidal epithelium. According to the current model, the neural retina and the posterior iris pigment epithelium (IPE) are derived from the inner wall of the optic cup, while the retinal pigment epithelium (RPE) and the anterior IPE are derived from the outer wall of the optic cup during development. Our current study shows evidence, contradicting this model of fetal iris development. We demonstrate that human fetal iris expression patterns of Otx2 and Mitf transcription factors are similar, while the expressions of Otx2 and Sox2 are complementary. Furthermore, IPE and RPE exhibit identical morphologic development during the early embryonic period. Our results suggest that the outer layer of the optic cup forms two layers of the iris epithelium, and the posterior IPE is the inward-curling anterior rim of the outer layer of the optic cup. These findings provide a reasonable explanation of how IPE cells can be used as an appropriate substitute for RPE cells.

  9. Neuropsychiatric Symptoms in Posterior Cortical Atrophy and Alzheimer Disease

    PubMed Central

    Crutch, Sebastian J.; Franco-Macías, Emilio; Gil-Néciga, Eulogio

    2016-01-01

    Background: Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome characterized by early progressive visual dysfunction in the context of relative preservation of memory and a pattern of atrophy mainly involving the posterior cortex. The aim of the present study is to characterize the neuropsychiatric profile of PCA. Methods: The Neuropsychiatric Inventory was used to assess 12 neuropsychiatric symptoms (NPS) in 28 patients with PCA and 34 patients with typical Alzheimer disease (AD) matched by age, disease duration, and illness severity. Results: The most commonly reported NPS in both groups were depression, anxiety, apathy, and irritability. However, aside from a trend toward lower rates of apathy in patients with PCA, there were no differences in the percentage of NPS presented in each group. All those patients presenting visual hallucinations in the PCA group also met diagnostic criteria for dementia with Lewy bodies (DLB). Auditory hallucinations were only present in patients meeting diagnosis criteria for DLB. Conclusion: Prevalence of the 12 NPS examined was similar between patients with PCA and AD. Hallucinations in PCA may be helpful in the differential diagnosis between PCA-AD and PCA-DLB. PMID:26404166

  10. [Peripheral anterior synechiae overlying the haptics of posterior chamber lenses].

    PubMed

    Li, M; Yin, Y; Chen, J

    1995-09-01

    To study the changes of the anterior chamber angle after intraocular lens implantation, 111 patients (130 eyes) with posterior chamber intraocular lens implantation at different post-operative periods were examined by gonioscopy. Peripheral anterior synechia overlying the position of the lens haptic (lens haptic PAS) was observed in up to 50.8% of eyes implanted with haptics vaulted anteriorly by 10%. The lens haptic PAS is easy to be identified, it is a broad based forward displacement of the peripheral iris adhesive to the anterior wall of the anterior chamber angle. The size of the PAS was of half to one o'clock position and occasionally it was of one and a half to two o'clock position. The differences between the rates of occurrence of lens haptic PAS were not significant at different post-operative periods (P > 0.05). 55.9% of the sulcus fixated and 42.3% of the capsular fixated eyes had lens haptic PAS (P > 0.05). There were more lens haptic PAS in eyes with horizontally oriented lens haptics (62.7%) than with lens haptics at vertical position (41.4%, P < 0.05). Regular gonioscopy for posterior chamber lens implantation was recommended.

  11. Finite Element Modeling of the Posterior Eye in Microgravity

    NASA Technical Reports Server (NTRS)

    Feola, Andrew; Raykin, Julia; Mulugeta, Lealem; Gleason, Rudolph; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian; Ethier, C. Ross

    2015-01-01

    Microgravity experienced during spaceflight affects astronauts in various ways, including weakened muscles and loss of bone density. Recently, visual impairment and intracranial pressure (VIIP) syndrome has become a major concern for space missions lasting longer than 30 days. Astronauts suffering from VIIP syndrome have changes in ocular anatomical and visual impairment that persist after returning to earth. It is hypothesized that a cephalad fluid shift in microgravity may increase the intracranial pressure (ICP), which leads to an altered biomechanical environment of the posterior globe and optic nerve sheath (ONS).Currently, there is a lack of knowledge of how elevated ICP may lead to vision impairment and connective tissue changes in VIIP. Our goal was to develop a finite element model to simulate the acute effects of elevated ICP on the posterior eye and optic nerve sheath. We used a finite element (FE) analysis approach to understand the response of the lamina cribrosa and optic nerve to the elevations in ICP thought to occur in microgravity and to identify which tissue components have the greatest impact on strain experienced by optic nerve head tissues.

  12. Chemical architecture of the posterior striatum in the human brain.

    PubMed

    Bernácer, J; Prensa, L; Giménez-Amaya, J M

    2008-01-01

    The neurochemical organization of the posterior caudate nucleus (CN) (body, gyrus and tail) and putamen (Put) was analyzed in the human brain using adjacent sections stained for acetylcholinesterase (AChE), limbic system-associated membrane protein (LAMP), enkephalin (ENK), parvalbumin (PV), calbindin (CB) and tyrosine hydroxylase (TH). Striosomes were visualized in all striatal regions but the anterior two thirds of the CN tail. They were highly immunoreactive (-ir) for ENK and LAMP, devoid of PV and AChE staining, and surrounded by a ring of tissue with pale TH- and CB-ir neuropil. In the Put, other rings of tissue completely free of ENK labeling surrounded certain striosomes (clear septa). In the CN body, gyrus and tail some markers revealed gradients and heterogeneities along the dorsoventral and mediolateral axes. A rim of striatal tissue densely stained for ENK and LAMP and poorly labeled for PV was noticeable along the lateral edge of the Put and the dorsolateral sector of the CN body. Our results illustrate a chemical architecture in the posterior striatum that is heterogeneous and slightly different from that found in the more anterior striatum.

  13. [Endoscopic interventions in tumors of the pineal area, posterior regions of the III ventricle, and the posterior cranial fossa].

    PubMed

    Sufianov, A A

    2000-01-01

    The study was undertaken to develop and introduce low-invasive differential endoneurosurgical correction of spinal fluid circulatory disorders in tumors of the pineal area, posterior portions of the third ventricle and the posteranial fossa. The authors present their experience in surgically treating 12 patients by using endoscopy. Surgical techniques, endoscopic semiotics of tumors of the above site, metastases along the liquor pathways are described. The outcomes of this treatment are analyzed. An algorithm of surgical treatment is proposed. Certain advantages of endoscopic interventions over conventional treatments in the treatment of tumor-induced occlusive hydrocephalus justify their inclusion into a comprehensive examination and treatment of patients of this study group.

  14. Topographically Organized Projection to Posterior Insular Cortex from the Posterior Portion of the Ventral Medial Nucleus (VMpo) in the Long-tailed Macaque Monkey

    PubMed Central

    Craig, A.D. (Bud)

    2014-01-01

    Prior anterograde tracing work identified somatotopically organized lamina I trigemino- and spino-thalamic terminations in a cytoarchitectonically distinct portion of posterolateral thalamus of the macaque monkey, named the posterior part of the ventral medial nucleus (VMpo; Craig, 2004b). Microelectrode recordings from clusters of selectively thermoreceptive or nociceptive neurons were used to guide precise micro-injections of various tracers in VMpo. A prior report (Craig and Zhang, 2006) described retrograde tracing results, which confirmed the selective lamina I input to VMpo and the antero-posterior (head to foot) topography. The present report describes the results of micro-injections of anterograde tracers placed at different levels in VMpo, based on the antero-posterior topographic organization of selectively nociceptive units and clusters over nearly the entire extent of VMpo. Each injection produced dense, patchy terminal labeling in a single coherent field within a distinct granular cortical area centered in the fundus of the superior limiting sulcus. The terminations were distributed with a consistent antero-posterior topography over the posterior half of the superior limiting sulcus. These observations demonstrate a specific VMpo projection area in dorsal posterior insular cortex that provides the basis for a somatotopic representation of selectively nociceptive lamina I spinothalamic activity. These results also identify the VMpo terminal area as the posterior half of interoceptive cortex; the anterior half receives input from the vagal-responsive and gustatory neurons in the basal part of the ventral medial nucleus (VMb). PMID:23853108

  15. Long-Term Outcome of Posterior Cervical Inclinatory Foraminotomy

    PubMed Central

    Heo, Juneyoung; Park, Hyung-Ki

    2016-01-01

    Objective A modified surgical technique of posterior cervical foramintomy called posterior cervical inclinatory foraminotomy (PCIF) was introduced in previous preliminary article. PCIF allows better preservation of facet joint and capsule than conventional techniques. The authors conducted a study to investigate long-term outcomes of PCIF. Methods We retrospectively reviewed demographic, radiologic, and clinical data from the patients who underwent PCIFs at our institution. Criteria included a minimum of 48 month follow-up and PCIFs for patients with radiculopathy from foraminal stenosis (C2–T1; single or multilevel) with persistent or recurrent root symptoms despite conservative treatment for more than 3 months. Patients who had undergone previous cervical operation were excluded. The visual analogue scale (VAS) score was used for clinical follow-up, and radiologic follow-up was performed to compare the changes of cervical sagittal alignment, focal angle and disc-space height of treated segment. Results The PCIFs were performed between April 2007 and March 2011 on 46 patients (32 males and 14 females) with a total of 73 levels affected. The average duration of follow-up was 74.4 months. Improvements in radiculopathic pain were seen in 39 patients (84.7%), and VAS score decreased from 6.82±1.9 to 2.19±1.9. Posterior neck pain also improved in 25 patients (71.4%) among 35 patients, and VAS score decreased from 4.97±2.0 to 2.71±1.9. The mean disc-space heights of treated segment were 5.41±1.03 mm preoperatively and decreased to 5.17±1.12 mm postoperatively. No statistically significant changes in cervical sagittal alignment, focal angle were seen during the follow-up period (Cox proportional hazards analysis and Student t-test, p>0.05). Conclusion The PCIF is highly effective in treating patients with cervical spondylotic radiculopathy, leading to long-lasting relief in pain. Long-term radiologic follow-up showed no significant spinal angular imbalance. PMID

  16. Multiple cytosolic calcium buffers in posterior pituitary nerve terminals.

    PubMed

    McMahon, Shane M; Chang, Che-Wei; Jackson, Meyer B

    2016-03-01

    Cytosolic Ca(2+) buffers bind to a large fraction of Ca(2+) as it enters a cell, shaping Ca(2+) signals both spatially and temporally. In this way, cytosolic Ca(2+) buffers regulate excitation-secretion coupling and short-term plasticity of release. The posterior pituitary is composed of peptidergic nerve terminals, which release oxytocin and vasopressin in response to Ca(2+) entry. Secretion of these hormones exhibits a complex dependence on the frequency and pattern of electrical activity, and the role of cytosolic Ca(2+) buffers in controlling pituitary Ca(2+) signaling is poorly understood. Here, cytosolic Ca(2+) buffers were studied with two-photon imaging in patch-clamped nerve terminals of the rat posterior pituitary. Fluorescence of the Ca(2+) indicator fluo-8 revealed stepwise increases in free Ca(2+) after a series of brief depolarizing pulses in rapid succession. These Ca(2+) increments grew larger as free Ca(2+) rose to saturate the cytosolic buffers and reduce the availability of Ca(2+) binding sites. These titration data revealed two endogenous buffers. All nerve terminals contained a buffer with a Kd of 1.5-4.7 µM, and approximately half contained an additional higher-affinity buffer with a Kd of 340 nM. Western blots identified calretinin and calbindin D28K in the posterior pituitary, and their in vitro binding properties correspond well with our fluorometric analysis. The high-affinity buffer washed out, but at a rate much slower than expected from diffusion; washout of the low-affinity buffer could not be detected. This work has revealed the functional impact of cytosolic Ca(2+) buffers in situ in nerve terminals at a new level of detail. The saturation of these cytosolic buffers will amplify Ca(2+) signals and may contribute to use-dependent facilitation of release. A difference in the buffer compositions of oxytocin and vasopressin nerve terminals could contribute to the differences in release plasticity of these two hormones. PMID:26880753

  17. Multiple cytosolic calcium buffers in posterior pituitary nerve terminals

    PubMed Central

    McMahon, Shane M.; Chang, Che-Wei

    2016-01-01

    Cytosolic Ca2+ buffers bind to a large fraction of Ca2+ as it enters a cell, shaping Ca2+ signals both spatially and temporally. In this way, cytosolic Ca2+ buffers regulate excitation-secretion coupling and short-term plasticity of release. The posterior pituitary is composed of peptidergic nerve terminals, which release oxytocin and vasopressin in response to Ca2+ entry. Secretion of these hormones exhibits a complex dependence on the frequency and pattern of electrical activity, and the role of cytosolic Ca2+ buffers in controlling pituitary Ca2+ signaling is poorly understood. Here, cytosolic Ca2+ buffers were studied with two-photon imaging in patch-clamped nerve terminals of the rat posterior pituitary. Fluorescence of the Ca2+ indicator fluo-8 revealed stepwise increases in free Ca2+ after a series of brief depolarizing pulses in rapid succession. These Ca2+ increments grew larger as free Ca2+ rose to saturate the cytosolic buffers and reduce the availability of Ca2+ binding sites. These titration data revealed two endogenous buffers. All nerve terminals contained a buffer with a Kd of 1.5–4.7 µM, and approximately half contained an additional higher-affinity buffer with a Kd of 340 nM. Western blots identified calretinin and calbindin D28K in the posterior pituitary, and their in vitro binding properties correspond well with our fluorometric analysis. The high-affinity buffer washed out, but at a rate much slower than expected from diffusion; washout of the low-affinity buffer could not be detected. This work has revealed the functional impact of cytosolic Ca2+ buffers in situ in nerve terminals at a new level of detail. The saturation of these cytosolic buffers will amplify Ca2+ signals and may contribute to use-dependent facilitation of release. A difference in the buffer compositions of oxytocin and vasopressin nerve terminals could contribute to the differences in release plasticity of these two hormones. PMID:26880753

  18. Recent progress in ocular drug delivery for posterior segment disease: emphasis on transscleral iontophoresis.

    PubMed

    Myles, Marvin E; Neumann, Donna M; Hill, James M

    2005-12-13

    Age-related macular degeneration, diabetic retinopathy, posterior uveitis, and retinitis due to glaucoma are leading causes of vision loss in the United States and other developed countries. Because these diseases are located in the posterior segment of the eye, topical application of ophthalmic medicines is of limited benefit, since topically applied drugs rarely reach therapeutic levels in the affected posterior tissues such as the choroid and retina. Intravitreal injections can deliver drugs to the posterior segment without the side effects associated with systemic administration. However, the repeated and long-term injections often needed may cause complications, such as vitreous hemorrhage, retinal detachment, or endophthalmitis. Recent advances in ocular drug delivery methods and the development of novel biopharmaceutical agents could lead to new regimens for the treatment of disease of the posterior retina, choroids, and macula. This review will summarize recent literature concerning ocular drug delivery of bioactive compounds to the posterior segment of the eye with emphasis on transscleral iontophoresis.

  19. Reverse shift mechanism for automotive manual transmission

    SciTech Connect

    Inui, M.; Ogawa, S.

    1987-03-03

    A reverse shift mechanism is described for an automotive manual transmission of a type having a reverse idler gear which is movable to selectively complete a reverse gear train, the reverse shift mechanism comprising: a reverse shift arm having a portion disposed adjacent the reverse idler gear and pivotally carried with respect to a transmission casing so that the portion rocks along a direction of axis of the reverse idler gear in response to shifting operation. The portion of the reverse shift arm is provided with a blind hole which is open at a first end toward the reverse idler gear and is closed at a second end away from the reverse idler gear; and a shift arm shoe carried by the portion of the reverse shift arm adjacent the reverse idler gear for pushing the reverse idler gear. The shift arm shoe has an end adapted to engage with a circumferential groove formed in the reverse idler gear and an opposing end shaped to fit in the blind hole of the reverse shift arm; whereby the shift arm shoe is prevented from coming off during assembly by virtue of a vacuum effect created by air confined in the blind hole by fitting engagement between the opposing end and the blind hole, and is held in place after assembly by being clamped between the groove of the reverse idler gear and the blind hole of the reverse shift arm.

  20. Dynamics and timing of reversals

    NASA Astrophysics Data System (ADS)

    Valet, J.-P.; Fournier, A.

    2012-04-01

    Information provided by records of geomagnetic reversals from lava sequences is constrained by irregular volcanic activity. We show that, despite different resolution, the ten most detailed volcanic records match surprisingly well and display the same dynamical characteristics after tuning to a common eruption rate. We thus infer that the reversal process has remained unchanged over the past 180Ma with the same time constants and duration. The reversing field is characterized by 3 successive episodes, a precursory event, a 180° polarity switch and a rebound. The first and third phases depict a large amplitude directional change which, by comparison with the archeological record, is estimated to last between 2 and 2.5 kyr. The transit between the two polarities does not exceed 1ka and is thus too fast for being properly recorded by most sediments. Similar results are obtained after reducing the directional clusters that are present at different periods in each record. These features and time constants are compatible with models that do not require any mantle control on reversals processes, which is also supported by the absence of preferred longitude of the pole. Lastly, based on the chronology of the successive reversal phases, the eruption rates are found to be at least twice larger for hot spots (<1flow/100yr) than for large flood basaltic provinces.

  1. Vasectomy reversal: a clinical update.

    PubMed

    Patel, Abhishek P; Smith, Ryan P

    2016-01-01

    Vasectomy is a safe and effective method of contraception used by 42-60 million men worldwide. Approximately 3%-6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and places a larger financial strain on the patient since it is usually not covered by insurance. Interest in this procedure has increased since the operating microscope became available in the 1970s, which consequently led to improved patency and pregnancy rates following the procedure. In this clinical update, we discuss patient evaluation, variables that may influence reversal success rates, factors to consider in choosing to perform vasovasostomy versus vasoepididymostomy, and the usefulness of vasectomy reversal to alleviate postvasectomy pain syndrome. We also review the use of robotics for vasectomy reversal and other novel techniques and instrumentation that have emerged in recent years to aid in the success of this surgery. PMID:26975488

  2. Vasectomy reversal: a clinical update

    PubMed Central

    Patel, Abhishek P; Smith, Ryan P

    2016-01-01

    Vasectomy is a safe and effective method of contraception used by 42–60 million men worldwide. Approximately 3%–6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and places a larger financial strain on the patient since it is usually not covered by insurance. Interest in this procedure has increased since the operating microscope became available in the 1970s, which consequently led to improved patency and pregnancy rates following the procedure. In this clinical update, we discuss patient evaluation, variables that may influence reversal success rates, factors to consider in choosing to perform vasovasostomy versus vasoepididymostomy, and the usefulness of vasectomy reversal to alleviate postvasectomy pain syndrome. We also review the use of robotics for vasectomy reversal and other novel techniques and instrumentation that have emerged in recent years to aid in the success of this surgery. PMID:26975488

  3. Reverse pupillary block associated with pigment dispersion syndrome after in-the-bag intraocular lens implantation.

    PubMed

    Itagaki, Hideo; Kunikata, Toshio; Hiratsuka, Kentaro; Saito, Junichiro; Oshika, Tetsuro

    2013-12-01

    A 61-year-old man with high myopia who had received a systemic α1A-adrenoceptor antagonist had phacoemulsification and in-the-bag intraocular lens implantation in the right eye. One day postoperatively, marked pigment dispersion in the anterior chamber, posterior bowing of the iris, and iridodonesis were noted associated with a subsequent elevation in intraocular pressure (IOP). Pharmacological pupil dilation was effective in reducing pigment dispersion and IOP, and laser peripheral iridotomy was performed to alleviate posterior bowing of the iris. We hypothesize that dynamic changes in the aqueous humor flow by cataract surgery and latent flaccidity of the iris due to the systemic α1A-adrenoceptor antagonist caused reverse pupillary block. High myopia may be another risk factor for this complication. PMID:24140374

  4. Call-fleming syndrome (reversible cerebral artery vasoconstriction) and aneurysm associated with multiple recreational drug use.

    PubMed

    Drazin, Doniel; Alexander, Michael J

    2013-01-01

    Drug abuse represents a significant health issue. Evidence suggests that recreational drug use has a direct effect on the cerebral vasculature and is of greater concern in those with undiagnosed aneurysms or vascular malformations. The authors report a case of thunderclap headache with a negative head CT and equivocal lumbar puncture after a drug-fueled weekend. The patient underwent diagnostic cerebral angiogram which demonstrated multisegmental, distal areas of focal narrowing of the middle, anterior, posterior, and posterior inferior cerebral artery and an incidental aneurysm. It is often difficult to determine the exact origin of symptoms; thus we were left with a bit of a chicken or the egg debate, trying to decipher which part came first. Either the aneurysm ruptured with associated concomitant vasospasm or it is a case of Call-Fleming syndrome (reversible cerebral artery vasoconstriction) with an incidental aneurysm. The authors proposed their management and rationale of this complex case.

  5. Complete transthoracic resection of giant posterior mediastinal goiter: case report and review of surgical strategies

    PubMed Central

    Zhao, Honglin; Ren, Dian; Liu, Yi; Li, Xin; Wu, Yi; Chen, Gang; Chen, Jun

    2016-01-01

    Intrathoracic goiters generally occupy anterior mediastinum, rarely involving the posterior mediastinal space. Reported herein is a 54-year-old female with a giant posterior mediastinal mass that was successfully resected via right posterolateral thoracotomy. The final pathologic diagnosis was giant posterior mediastinal goiter. This patient has done well postoperatively, with no evidence of local recurrence at 12-month follow-up. Related surgical strategies in past publications are summarized. PMID:27217766

  6. Identification of Bayesian posteriors for coefficients of chaos expansions

    SciTech Connect

    Arnst, M. Ghanem, R.; Soize, C.

    2010-05-01

    This article is concerned with the identification of probabilistic characterizations of random variables and fields from experimental data. The data used for the identification consist of measurements of several realizations of the uncertain quantities that must be characterized. The random variables and fields are approximated by a polynomial chaos expansion, and the coefficients of this expansion are viewed as unknown parameters to be identified. It is shown how the Bayesian paradigm can be applied to formulate and solve the inverse problem. The estimated polynomial chaos coefficients are hereby themselves characterized as random variables whose probability density function is the Bayesian posterior. This allows to quantify the impact of missing experimental information on the accuracy of the identified coefficients, as well as on subsequent predictions. An illustration in stochastic aeroelastic stability analysis is provided to demonstrate the proposed methodology.

  7. Thoracoscopic resection of functional posterior mediastinal paraganglioma: a case report

    PubMed Central

    Ma, Lin; Mei, Jianong

    2014-01-01

    A 48-year-old man with posterior mediastinal mass was diagnosed as functional mediastinal paraganglioma during surgical exploration via open thoracotomy in another hospital. The operation was terminated because of severe hypertension when touching the tumor. He was transferred to our center later. After systemic evaluation, the patient was medicated with oral alpha- and beta-blockades, as well as intravenous fluid resuscitation for two weeks. His blood pressure became stable and a second operation was planned. The tumor was removed completely via the thoracoscopic approach, and was finally confirmed as functional paraganglioma by immunohistochemistry. The patient recovered uneventfully after surgery, with no recurrence during one year follow-up visit. PMID:25589992

  8. Posterior spinal artery aneurysm rupture after 'Ecstasy' abuse.

    PubMed

    Johnson, Jeremiah; Patel, Shnehal; Saraf-Lavi, Efrat; Aziz-Sultan, Mohammad Ali; Yavagal, Dileep R

    2014-01-01

    Posterior spinal artery (PSA) aneurysms are a rare cause of subarachnoid hemorrhage (SAH). The commonly abused street drug 3,4-methylenedioxymethamphetamine (MDMA) or 'Ecstasy' has been linked to both systemic and neurological complications. A teenager presented with neck stiffness, headaches and nausea after ingesting 'Ecstasy'. A brain CT was negative for SAH but a CT angiogram suggested cerebral vasculitis. A lumbar puncture showed SAH but a cerebral angiogram was negative. After a spinal MR angiogram identified abnormalities on the dorsal surface of the cervical spinal cord, a spinal angiogram demonstrated a left PSA 2 mm fusiform aneurysm. The patient underwent surgery and the aneurysmal portion of the PSA was excised without postoperative neurological sequelae. 'Ecstasy' can lead to neurovascular inflammation, intracranial hemorrhage, SAH and potentially even de novo aneurysm formation and subsequent rupture. PSA aneurysms may be treated by endovascular proximal vessel occlusion or open surgical excision.

  9. Anatomical study of a posterior cerebral lesion producing dyslexia.

    PubMed

    Van Buren, J M

    1979-07-01

    After an "occipital lobectomy" that resulted in a severe dyslexia and a moderate dysgraphia-dyscalculia, anatomical study showed damage to the posterior extremity of the angular gyrus and degeneration in the posteroinferior pulvinar. This is in contrast to an earlier case that had degeneration in the anterosuperior pulvinor associated with a small anterior temporoparietal infarct and a well-documented receptive-expressive aphasia. However, the role of the pulvinar in speech function remains uncertain. The surgeon should be aware of the short distance between the angular gyrus and both the midline and the occipital pole because a lesion here during an "occipital lobectomy" produces a distressing and durable speech impairment. PMID:471199

  10. Popliteal pseudoaneurysm after arthroscopic posterior cruciate ligament reconstruction.

    PubMed

    van Dorp, Karin B; Breugem, Stefan J M; Driessen, Marcel J M

    2014-09-01

    This report presents the case of a 30-year-old motocross (BMX) cyclist with a third-degree posterior cruciate ligament rupture. The technique used for reconstruction was the transtibial single-bundle autologous hamstring technique. Unfortunately, the procedure was complicated by a popliteal pseudoaneurysm, which was located in line with the tibial canal. The pseudoaneurysm was treated with an end-to-end anastomosis and the patient recovered without further complaints. In this case, the popliteal artery was damaged most probably by the edge of the reamer or the guide wire during removal. Vascular complications can be limb- and life-threatening. This case report aims to increase the awareness of this serious complication with a review of the literature. PMID:25229050

  11. Tibial inlay posterior cruciate ligament reconstruction: surgical technique and results.

    PubMed

    McAllister, David R; Hussain, Suleman M

    2010-12-01

    Posterior cruciate ligament (PCL) injuries occur much less frequently than other ligament injuries of the knee such as anterior cruciate ligament injuries. There is general agreement for nonoperative treatment for lower grade injuries such as type I PCL injuries. However, for more severe injuries which may require surgery, there is no consensus on an optimal reconstruction method. Multiple arthroscopic and open techniques exist to reconstruct the PCL. Limited clinical outcomes data reveals good short-term clinical results with different reconstruction options. Biomechanical data has helped further the understanding regarding the performance of different reconstructions. This article will present a surgical technique for single bundle tibial inlay reconstruction of the PCL along with the objective biomechanical data that supports this reconstruction.

  12. Multiexpandable cage for minimally invasive posterior lumbar interbody fusion

    PubMed Central

    Coe, Jeffrey D; Zucherman, James F; Kucharzyk, Donald W; Poelstra, Kornelis A; Miller, Larry E; Kunwar, Sandeep

    2016-01-01

    The increasing adoption of minimally invasive techniques for spine surgery in recent years has led to significant advancements in instrumentation for lumbar interbody fusion. Percutaneous pedicle screw fixation is now a mature technology, but the role of expandable cages is still evolving. The capability to deliver a multiexpandable interbody cage with a large footprint through a narrow surgical cannula represents a significant advancement in spinal surgery technology. The purpose of this report is to describe a multiexpandable lumbar interbody fusion cage, including implant characteristics, intended use, surgical technique, preclinical testing, and early clinical experience. Results to date suggest that the multiexpandable cage allows a less invasive approach to posterior/transforaminal lumbar interbody fusion surgery by minimizing iatrogenic risks associated with static or vertically expanding interbody prostheses while providing immediate vertebral height restoration, restoration of anatomic alignment, and excellent early-term clinical results. PMID:27729817

  13. Transient contribution of left posterior parietal cortex to cognitive restructuring

    PubMed Central

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-01-01

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

  14. Asymptotic approximations to posterior distributions via conditional moment equations

    USGS Publications Warehouse

    Yee, J.L.; Johnson, W.O.; Samaniego, F.J.

    2002-01-01

    We consider asymptotic approximations to joint posterior distributions in situations where the full conditional distributions referred to in Gibbs sampling are asymptotically normal. Our development focuses on problems where data augmentation facilitates simpler calculations, but results hold more generally. Asymptotic mean vectors are obtained as simultaneous solutions to fixed point equations that arise naturally in the development. Asymptotic covariance matrices flow naturally from the work of Arnold & Press (1989) and involve the conditional asymptotic covariance matrices and first derivative matrices for conditional mean functions. When the fixed point equations admit an analytical solution, explicit formulae are subsequently obtained for the covariance structure of the joint limiting distribution, which may shed light on the use of the given statistical model. Two illustrations are given. ?? 2002 Biometrika Trust.

  15. Simple posterior frequency correction for vibrational spectra from molecular dynamics.

    PubMed

    Tikhonov, Denis S

    2016-05-01

    Vibrational spectra computed from molecular dynamics simulations with large integration time steps suffer from nonphysical frequency shifts of signals [M. Praprotnik and D. Janežič, J. Chem. Phys. 122, 174103 (2005)]. A simple posterior correction technique was developed for compensation of this behavior. It performs through replacement of abscissa in the calculated spectra using following formula: νcorrected=2⋅1-cos(2π⋅Δt⋅νinitial)2π⋅Δt, where ν are initial and corrected frequencies and Δt is the MD simulation time step. Applicability of this method was tested on gaseous infrared spectra of hydrogen fluoride and formic acid. PMID:27155626

  16. A case of pulmonary hyalinizing granuloma associated with posterior uveitis.

    PubMed

    Esme, Hidir; Ermis, Sitki Samet; Fidan, Fatma; Unlu, Mehmet; Dilek, Fatma Husniye

    2004-09-01

    A 48-year-old male was admitted to our hospital because of abnormal pulmonary shadows and a decrease in visual acuity. He had a history of tuberculosis 20 years ago. The chest roentgenogram showed multiple pulmonary nodules throughout both lung fields. No definitive diagnosis was established either by brushing cytology or biopsy through bronchoscopy or percutaneous needle biopsy. Pathological examination of open lung biopsy specimen revealed that extensive, hyalinized lamellar collagen bundles arranged in whorls, parallel arrays. Plasma cells and lymphocytes were found between the collagen bands and germinal centers were seen at the periphery of the lesion. A definitive diagnosis of pulmonary hyalinizing granuloma was made on the basis of these histopathological findings. Although there is no established treatment for pulmonary hyalinizing granuloma, during 1 month of follow-up, posterior uveitis mildly resolved with glucocorticoid treatment and there had been a slight increase in visual acuity. PMID:15329468

  17. Mapping genes with longitudinal phenotypes via Bayesian posterior probabilities.

    PubMed

    Musolf, Anthony; Nato, Alejandro Q; Londono, Douglas; Zhou, Lisheng; Matise, Tara C; Gordon, Derek

    2014-01-01

    Most association studies focus on disease risk, with less attention paid to disease progression or severity. These phenotypes require longitudinal data. This paper presents a new method for analyzing longitudinal data to map genes in both population-based and family-based studies. Using simulated systolic blood pressure measurements obtained from Genetic Analysis Workshop 18, we cluster the phenotype data into trajectory subgroups. We then use the Bayesian posterior probability of being in the high subgroup as a quantitative trait in an association analysis with genotype data. This method maintains high power (>80%) in locating genes known to affect the simulated phenotype for most specified significance levels (α). We believe that this method can be useful to aid in the discovery of genes that affect severity or progression of disease. PMID:25519410

  18. Posterior cerebral artery stroke presenting as alexia without agraphia.

    PubMed

    Sharma, Bhawna; Handa, Rahul; Prakash, Swayam; Nagpal, Kadam; Bhana, Indu; Gupta, Pankaj Kumar; Kumar, Sunil; Sisodiya, Mahendra Singh

    2014-12-01

    Alexia without agraphia (pure alexia) was the first of the disconnection syndromes to be described by Dejerine who reported a patient of alexia without agraphia secondary to an embolic occipital lobe infarct. We herein report a 55-year-old man who presented with alexia without agraphia with magnetic resonance imaging suggestive of left posterior cerebral artery infarct involving left occipital lobe and splenium of corpus callosum. Alexia without agraphia is a relatively uncommon clinical condition, which should always be thought in a patient presenting with difficulty in reading with normal visual acuity. Ophthalmologists should also be aware of this disconnection syndrome as many patients initially take their advice due to predominant visual complaints. Early diagnosis and treatment of this condition help in ensuring the patient and attendants about nonprogressive nature of the disease and may prevent further episodes of stroke. PMID:24935413

  19. Cellular mechanisms of posterior neural tube morphogenesis in the zebrafish.

    PubMed

    Harrington, Michael J; Chalasani, Kavita; Brewster, Rachel

    2010-03-01

    The zebrafish is a well established model system for studying neural development, yet neurulation remains poorly understood in this organism. In particular, the morphogenetic movements that shape the posterior neural tube (PNT) have not been described. Using tools for imaging neural tissue and tracking the behavior of cells in real time, we provide the first comprehensive analysis of the cellular events shaping the PNT. We observe that this tissue is formed in a stepwise manner, beginning with merging of presumptive neural domains in the tailbud (Stage 1); followed by neural convergence and infolding to shape the neural rod (Stage 2); and continued elongation of the PNT, in absence of further convergence (Stage 3). We further demonstrate that cell proliferation plays only a minimal role in PNT elongation. Overall, these mechanisms resemble those previously described in anterior regions, suggesting that, in contrast to amniotes, neurulation is a fairly uniform process in zebrafish.

  20. Laparoscopic Pancreaticoduodenectomy: Right Posterior Superior Mesenteric Artery "First" Approach.

    PubMed

    Pittau, Gabriella; Sànchez-Cabùs, Santiago; Laurenzi, Andrea; Gelli, Maximiliano; Cunha, Antonio Sa

    2015-12-01

    Pancreaticoduodenectomy (PD) is considered one of the most challenging abdominal operations for several reasons, including the anatomy, which is surrounded by vital vascular structures and also because of the serious complications that are possible in the postoperative period. Nowadays, thanks to the development of minimally invasive surgery and improvement of patients' selection, laparoscopic pancreatic resections have been proven to be technically feasible and safe especially in the case of left pancreatectomies. More recently, many series of laparoscopic PD for adenocarcinoma have been published demonstrating the feasibility of this technique. In pancreatic cancer, the advantage of superior mesenteric artery "first approach" is already known to achieve an oncological resection. The purpose of this video is to describe the different technical aspects of the laparoscopic superior mesenteric artery first approach in the right posterior fashion.

  1. Posterior spinal artery aneurysm rupture after 'Ecstasy' abuse.

    PubMed

    Johnson, Jeremiah; Patel, Shnehal; Saraf-Lavi, Efrat; Aziz-Sultan, Mohammad Ali; Yavagal, Dileep R

    2015-07-01

    Posterior spinal artery (PSA) aneurysms are a rare cause of subarachnoid hemorrhage (SAH). The commonly abused street drug 3,4-methylenedioxymethamphetamine (MDMA) or 'Ecstasy' has been linked to both systemic and neurological complications. A teenager presented with neck stiffness, headaches and nausea after ingesting 'Ecstasy'. A brain CT was negative for SAH but a CT angiogram suggested cerebral vasculitis. A lumbar puncture showed SAH but a cerebral angiogram was negative. After a spinal MR angiogram identified abnormalities on the dorsal surface of the cervical spinal cord, a spinal angiogram demonstrated a left PSA 2 mm fusiform aneurysm. The patient underwent surgery and the aneurysmal portion of the PSA was excised without postoperative neurological sequelae. 'Ecstasy' can lead to neurovascular inflammation, intracranial hemorrhage, SAH and potentially even de novo aneurysm formation and subsequent rupture. PSA aneurysms may be treated by endovascular proximal vessel occlusion or open surgical excision.

  2. Changes in artistic style after minor posterior stroke

    PubMed Central

    Annoni, J; Devuyst, G; Carota, A; Bruggimann, L; Bogousslavsky, J

    2005-01-01

    Background: Two professional painters experienced significant changes in their art as the main consequence of minor stroke located in the left occipital lobe or thalamus. Methods: The features of this artistic conversion were analysed on the basis of extensive neurological, neuropsychological, and psychiatric evaluations. Results: Both painters, initially unaware of the artistic changes, exhibited mild signs of executive dysfunction, but no general cognitive decline. The first painter, who showed mild visual-perceptive difficulties (dyschromatopsia and scotoma in his right upper visual field after left occipital stroke), together with increased anxiety and difficulty in emotional control, switched to a more stylised and symbolic art. The second painter, who also presented features of emotionalism related to his left latero-thalamic stroke, switched from an impressionist style to a more joyous and geometric, but more simplistic, abstract art. Conclusions: These findings show that mild cognitive and affective modifications due to focal posterior brain lesions can have significant repercussions on artistic expression. PMID:15897501

  3. Neglected Posterior Dislocation of Hip in Children - A Case Report

    PubMed Central

    Pal, Chandra Prakash; Kumar, Deepak; Sadana, Ashwani; Dinkar, Karuna Shankar

    2014-01-01

    Introduction: Traumatic dislocation of the hip in children is a rare injury. We report the outcome of 2 patients of neglected hip dislocation which were treated by open reduction and internal fixation by k-wires. Case Report: We treat 2 children both girls (one was of 4 years and other was 7 years of age). In both cases dislocation was unilateral and was not associated with any facture. Both cases were of posterior dislocation. in both cases open reduction and internal fixation was done by k wires. Hip spica was applied post operatively in both cases. The k wire was removed at 3 to 4 weeks. Patients were allowed to bear weight from gradual to full weight bearing after 6 weeks. Conclusion: We conclude that open reduction is a satisfactory treatment for neglected hip dislocation. It prevents not only deformity but also maintains limb length. PMID:27298953

  4. Posterior sternoclavicular epiphyseal fracture-dislocation with delayed diagnosis.

    PubMed

    Carmichael, Kelly D; Longo, Anthony; Lick, Scott; Swischuk, Leonard

    2006-08-01

    Posterior sternoclavicular joint dislocations and epiphyseal fractures are relatively rare injuries. We present a case report of a 16-year-old male who presented with a 10-day delay in diagnosis. The medial clavicular fragment was widely displaced and rested against the cervical vertebral body. Despite the degree of displacement, the patient had very few symptoms, and the diagnosis was not appreciated in the emergency department and became apparent at 10-day clinic follow-up. Treatment consisted of attempts at closed reduction, which were not successful. Open reduction was performed and the repair done with strong sutures. At 1-year follow-up the patient is doing well without any symptoms. A literature review consisting of anatomy, ossification patterns, classification systems, diagnosis and associated symptoms, imaging recommendations, treatment recommendations, outcomes, and complications is included.

  5. Ice ages and geomagnetic reversals

    NASA Technical Reports Server (NTRS)

    Wu, Patrick

    1992-01-01

    There have been speculations on the relationship between climatic cooling and polarity reversals of the earth's magnetic field during the Pleistocene. Two of the common criticisms on this relationship have been the reality of these short duration geomagnetic events and the accuracy of their dates. Champion et al. (1988) have reviewed recent progress in this area. They identified a total of 10 short-duration polarity events in the last 1 Ma and 6 of these events have been found in volcanic rocks, which also have K-Ar dates. Supposing that the speculated relationship between climatic cooling and geomagnetic reversals actually exist, two mechanisms that assume climatic cooling causes short period magnetic reversals will be investigated. These two methods are core-mantle boundary topography and transfer of the rotational energy to the core.

  6. Children's vomiting following posterior fossa surgery: A retrospective study

    PubMed Central

    Neufeld, Susan M; Newburn-Cook, Christine V; Schopflocher, Donald; Dundon, Belinda; Yu, Herta; Drummond, Jane E

    2009-01-01

    Background Nausea and vomiting is a problem for children after neurosurgery and those requiring posterior fossa procedures appear to have a high incidence. This clinical observation has not been quantified nor have risk factors unique to this group of children been elucidated. Methods A six year retrospective chart audit at two Canadian children's hospitals was conducted. The incidence of nausea and vomiting was extracted. Hierarchical multivariable logistic regression was used to quantify risk and protective factors at 120 hours after surgery and early vs. late vomiting. Results The incidence of vomiting over a ten day postoperative period was 76.7%. Documented vomiting ranged from single events to greater than 20 over the same period. In the final multivariable model: adolescents (age 12 to <17) were less likely to vomit by 120 hours after surgery than other age groups; those who received desflurane, when compared to all other volatile anesthetics, were more likely to vomit, yet the use of ondansetron with desflurane decre kelihood. Children who had intraoperative ondansetron were more likely to vomit in the final multivariable model (perhaps because of its use, in the clinical judgment of the anesthesiologist, for children considered at risk). Children who started vomiting in the first 24 hours were more likely to be school age (groups 4 to <7 and 7 to <12) and receive desflurane. Nausea was not well documented and was therefore not analyzed. Conclusion The incidence of vomiting in children after posterior fossa surgery is sufficient to consider all children requiring these procedures to be at high risk for POV. Nausea requires better assessment and documentation. PMID:19594935

  7. Posterior tibial tendon dysfunction and flatfoot: analysis with simulated walking.

    PubMed

    Watanabe, Kota; Kitaoka, Harold B; Fujii, Tadashi; Crevoisier, Xavier; Berglund, Lawrence J; Zhao, Kristin D; Kaufman, Kenton R; An, Kai-Nan

    2013-02-01

    Many biomechanical studies investigated pathology of flatfoot and effects of operations on flatfoot. The majority of cadaveric studies are limited to the quasistatic response to static joint loads. This study examined the unconstrained joint motion of the foot and ankle during stance phase utilizing a dynamic foot-ankle simulator in simulated stage 2 posterior tibial tendon dysfunction (PTTD). Muscle forces were applied on the extrinsic tendons of the foot using six servo-pneumatic cylinders to simulate their action. Vertical and fore-aft shear forces were applied and tibial advancement was performed with the servomotors. Three-dimensional movements of multiple bones of the foot were monitored with a magnetic tracking system. Twenty-two fresh-frozen lower extremities were studied in the intact condition, then following sectioning peritalar constraints to create a flatfoot and unloading the posterior tibial muscle force. Kinematics in the intact condition were consistent with gait analysis data for normals. There were altered kinematics in the flatfoot condition, particularly in coronal and transverse planes. Calcaneal eversion relative to the tibia averaged 11.1±2.8° compared to 5.8±2.3° in the normal condition. Calcaneal-tibial external rotation was significantly increased in flatfeet from mean of 2.3±1.7° to 8.1±4.0°. There were also significant changes in metatarsal-tibial eversion and external rotation in the flatfoot condition. The simulated PTTD with flatfoot was consistent with previous data obtained in patients with PTTD. The use of a flatfoot model will enable more detailed study on the flatfoot condition and/or effect of surgical treatment.

  8. Interstitial pressure measurements in the anterior and posterior compartments in athletes with shin splints.

    PubMed

    D'Ambrosia, R D; Zelis, R F; Chuinard, R G; Wilmore, J

    1977-01-01

    We found no basis for increased intercompartmental pressure in either the anterior or posterior compartments as the cause of shin splints. The pain in all 14 of the patients studied was localized to the posterior medial border of the tibia at the origin of the posterior tibial muscle, and evidence of periostitis in this area was seen in two of our patients, suggesting the possible tearing away of the posterior tibial muscle from its origin. Shin splints is a lay term which has assumed medical diagnostic significance and should be removed from common usage by more accurately localizing the focus of pain.

  9. Restoring proximal integrity in posterior composite resin restorations: innovations using Ceromers.

    PubMed

    Liebenberg, W H

    1998-03-01

    Clinicians are increasingly being called upon to satisfy the restorative demands of patients requesting tooth coloured restorations but unable to afford an optimum indirect restorative option. Consequently, in clinical practice the envelope of what was hitherto considered the limit of appropriate application of the direct posterior composite resin technique is increasingly being stretched. Although our aesthetic endeavours are fairly easily accomplished in the posterior dentition, interproximal integrity is in many instances wanting and a major cause of restorative failure. This report highlights some of the authors innovations using Ceromers which satisfy the complex variables of clinical practice optimizing proximal contour, allowing for the successful utilization of posterior composite resin in the posterior dentition.

  10. Posterior cerebral artery infarcts and semantic category dissociations: a study of 28 patients.

    PubMed

    Capitani, Erminio; Laiacona, Marcella; Pagani, Rossella; Capasso, Rita; Zampetti, Patrizia; Miceli, Gabriele

    2009-04-01

    In this study we analysed the relationship between damage in the territory of the posterior cerebral artery and semantic knowledge, with special reference to category dissociations. Twenty-eight posterior cerebral artery stroke patients (18 left, 8 right and 2 bilateral posterior cerebral artery infarctions) completed a neuropsychological battery aimed at assessing semantic knowledge. The battery included picture naming, word-picture matching, a verbal semantic questionnaire and a picture reality decision task. For each participant, the lesion was reconstructed on the basis of MRI images, and was classified according to the involvement of the areas supplied by posterior cerebral artery. Defective naming scores were observed in 12 of 18 left posterior cerebral artery cases (67%), four of eight right posterior cerebral artery cases (50%), and one of two bilateral posterior cerebral artery cases (50%). Only in the bilateral posterior cerebral artery lesion case did we observe the pattern expected in pure visual agnosia, i.e. poor picture naming, poor picture reality decision, and normal verbal semantic questionnaire. Nine left posterior cerebral artery cases and two right posterior cerebral artery cases presented with poor performance on both the picture naming task and the verbal semantic questionnaire, thus suggesting semantic impairment. For 5 of the 12 left posterior cerebral artery patients who fared poorly on the naming task, biological stimuli (overall) were significantly more impaired than artifacts. In three of these five subjects, performance on plant-life stimuli was significantly less accurate than that on animals. A further left posterior cerebral artery patient presented a disproportionate impairment on plant-life stimuli only on the word-picture matching and on the questionnaire. The patterns of performance in these subjects suggest that the observed dissociations originated at the semantic level. Among left posterior cerebral artery patients, a naming

  11. Can the human lumbar posterior columns be stimulated by transcutaneous spinal cord stimulation? A modeling study.

    PubMed

    Danner, Simon M; Hofstoetter, Ursula S; Ladenbauer, Josef; Rattay, Frank; Minassian, Karen

    2011-03-01

    Stimulation of different spinal cord segments in humans is a widely developed clinical practice for modification of pain, altered sensation, and movement. The human lumbar cord has become a target for modification of motor control by epidural and, more recently, by transcutaneous spinal cord stimulation. Posterior columns of the lumbar spinal cord represent a vertical system of axons and when activated can add other inputs to the motor control of the spinal cord than stimulated posterior roots. We used a detailed three-dimensional volume conductor model of the torso and the McIntyre-Richard-Grill axon model to calculate the thresholds of axons within the posterior columns in response to transcutaneous lumbar spinal cord stimulation. Superficially located large-diameter posterior column fibers with multiple collaterals have a threshold of 45.4 V, three times higher than posterior root fibers (14.1 V). With the stimulation strength needed to activate posterior column axons, posterior root fibers of large and small diameters as well as anterior root fibers are coactivated. The reported results inform on these threshold differences, when stimulation is applied to the posterior structures of the lumbar cord at intensities above the threshold of large-diameter posterior root fibers. PMID:21401670

  12. Posterior tibial tendon tears in young competitive athletes: two case reports.

    PubMed

    Porter, D A; Baxter, D E; Clanton, T O; Klootwyk, T E

    1998-09-01

    Unlike the Achilles tendon, the posterior tibial tendon does not typically undergo acute rupture. We report two cases of posterior tibial tendon tears occurring in young, athletic individuals (<30 years old) that required operative intervention before the patients could return to competitive sports. We believe that these are the first two reports of posterior tibial tendon tears occurring in this population without the patient having a prior history of steroid injections in the tendon. The tears we observed and described at surgical exploration were chronic and degenerative in nature. We also comment on our approach to treatment of posterior tibial tendon injuries in the athletic population.

  13. Time-reversed, flow-reversed ballistics simulations

    SciTech Connect

    Zernow, L.; Chapyak, E. J.; Scheffler, D. R.

    2001-01-01

    Two-dimensional simulations of planar sheet jet formation are studied to examine the hydrodynamic issues involved when simulations are carried out in the inverse direction, that is, with reversed time and flow. Both a realistic copper equation of state and a shockless equation of state were used. These studies are an initial step in evaluating this technique as a ballistics design tool.

  14. Marburg Virus Reverse Genetics Systems

    PubMed Central

    Schmidt, Kristina Maria; Mühlberger, Elke

    2016-01-01

    The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family and belongs to the group of nonsegmented negative-strand RNA viruses. Reverse genetics systems established for MARV have been used to study various aspects of the viral replication cycle, analyze host responses, image viral infection, and screen for antivirals. This article provides an overview of the currently established MARV reverse genetic systems based on minigenomes, infectious virus-like particles and full-length clones, and the research that has been conducted using these systems. PMID:27338448

  15. Stagnation point reverse flow combustor

    NASA Technical Reports Server (NTRS)

    Zinn, Ben T. (Inventor); Neumeier, Yedidia (Inventor); Seitzman, Jerry M. (Inventor); Jagoda, Jechiel (Inventor); Weksler, Yoav (Inventor)

    2008-01-01

    A method for combusting a combustible fuel includes providing a vessel having an opening near a proximate end and a closed distal end defining a combustion chamber. A combustible reactants mixture is presented into the combustion chamber. The combustible reactants mixture is ignited creating a flame and combustion products. The closed end of the combustion chamber is utilized for directing combustion products toward the opening of the combustion chamber creating a reverse flow of combustion products within the combustion chamber. The reverse flow of combustion products is intermixed with combustible reactants mixture to maintain the flame.

  16. Reversing: A Fundamental Idea in Computer Science

    ERIC Educational Resources Information Center

    Armoni, Michal; Ginat, David

    2008-01-01

    Reversing is the notion of thinking or working in reverse. Computer science textbooks and tutors recognize it primarily in the form of recursion. However, recursion is only one form of reversing. Reversing appears in the computer science curriculum in many other forms, at various intellectual levels, in a variety of fundamental courses. As such,…

  17. Reversible antisocial behavior in ventromedial prefrontal lobe epilepsy.

    PubMed

    Trebuchon, Agnès; Bartolomei, Fabrice; McGonigal, Aileen; Laguitton, Virginie; Chauvel, Patrick

    2013-11-01

    Frontal lobe dysfunction is known to be associated with impairment in social behavior. We investigated the link between severe pharmacoresistant frontal lobe epilepsy and antisocial trait. We studied four patients with pharmacoresistant epilepsy involving the prefrontal cortex, presenting abnormal interictal social behavior. Noninvasive investigations (video-EEG, PET, MRI) and intracerebral recording (stereoelectroencephalography (SEEG)) were performed as part of a presurgical assessment. Comprehensive psychiatric and cognitive evaluation was performed pre- and postoperatively for frontal lobe epilepsy, with at least 7years of follow-up. All patients shared a characteristic epilepsy pattern: (1) chronic severe prefrontal epilepsy with daily seizures and (2) an epileptogenic zone as defined by intracerebral recording involving the anterior cingulate cortex, ventromedial PFC, and the posterior part of the orbitofrontal cortex, with early propagation to contralateral prefrontal and ipsilateral medial temporal structures. All patients fulfilled the diagnostic criteria (DSM-IV) of antisocial personality disorder, which proved to be reversible following seizure control. Pharmacoresistant epilepsy involving a prefrontal network is associated with antisocial personality. We hypothesize that the occurrence of frequent seizures in this region over a prolonged period produces functional damage leading to impaired prefrontal control of social behavior. This functional damage is reversible since successful epilepsy surgery markedly improved antisocial behavior in these patients. The results are in line with previous reports of impairment of social and moral behavior following ventromedial frontal lobe injury.

  18. Temporal pattern of the posterior expression of Wingless in Drosophila blastoderm

    PubMed Central

    Vorwald-Denholtz, Peggy P.; De Robertis, Edward M.

    2011-01-01

    In most animals, the Antero-Posterior (A-P) axis requires a gradient of Wnt signaling. Wnts are expressed posteriorly in many vertebrate and invertebrate embryos, forming a gradient of canonical Wnt/β-Catenin activity that is highest in the posterior and lowest in the anterior. One notable exception to this evolutionary conservation is in the Drosophila embryo, in which the A-P axis is established by early transcription factors of maternal origin. Despite this initial axial establishment, Drosophila still expresses Wingless (Wg), the main Drosophila Wnt homologue, in a strong posterior band early in embryogenesis. Since its discovery 30 years ago this posterior band of Wg has been largely ignored. In this study, we re-examined the onset of expression of the Wg posterior band in relation to the expression of Wg in other segments, and compared the timing of its expression to that of axial regulators such as gap and pair-rule genes. It was found that the posterior band of Wg is first detected in blastoderm at mid nuclear cycle 14, before the segment-polarity stripes of Wg are formed in other segments. The onset of the posterior band of Wg expression was preceded by that of the gap gene products Hunchback (hb) and Krüppel (Kr), and the pair-rule protein Even-skipped (Eve). Although the function of the posterior band of Wg was not analyzed in this study, we note that in temperature-sensitive Wg mutants, in which Wg is not properly secreted, the posterior band of Wg expression is diminished in strength, indicating a positive feedback loop required for Wg robust expression at the cellular blastoderm stage. We propose that this early posterior expression could play a role in the refinement of A-P patterning. PMID:21821151

  19. Therapeutic Progress in Treating Vertebral Dissecting Aneurysms Involving the Posterior Inferior Cerebellar Artery

    PubMed Central

    Shi, Lei; Xu, Kan; Sun, Xiaofeng; Yu, Jinlu

    2016-01-01

    Among the variations of vertebral artery dissecting aneurysms (VDAs), VDAs involving the posterior inferior cerebellar artery (PICA), especially ruptured and high-risk unruptured aneurysms, are the most difficult to treat. Because the PICA is an important structure, serious symptoms may occur after its occlusion. Retained PICAs are prone to re-bleeding because VDAs are difficult to completely occlude. There is therefore confusion regarding the appropriate treatment for VDAs involving the PICA. Here, we used the PubMed database to review recent research concerning VDAs that involve the PICA, and we found that treatments for VDAs involving the PICA include (i) endovascular treatment involving the reconstruction of blood vessels and blood flow, (ii) occluding the aneurysm using an internal coil trapping or an assisted bypass, (iii) inducing reversed blood flow by occluding the proximal VDA or forming an assisted bypass, or (iv) the reconstruction of blood flow via a craniotomy. Although the above methods effectively treat VDAs involving the PICA, each method is associated with both a high degree of risk and specific advantages and disadvantages. The core problem when treating VDAs involving the PICA is to retain the PICA while occluding the aneurysm. Therefore, the method is generally selected on a case-by-case basis according to the characteristics of the aneurysm. In this study, we summarize the various current methods that are used to treat VDAs involving the PICA and provide schematic diagrams as our conclusion. Because there is no special field of research concerning VDAs involving the PICA, these cases are hidden within many multiple-cases studies. Therefore, this study does not review all relevant documents and may have some limitations. Thus, we have focused on the mainstream treatments for VDAs that involve the PICA. PMID:27429591

  20. A Note on Reverse Derivations

    ERIC Educational Resources Information Center

    Samman, M.

    2005-01-01

    In this note, the notion of reverse derivation is studied. It is shown that in the class of semiprime rings, this notion coincides with the usual derivation when it maps a semiprime ring into its centre. However, we provide some examples to show that it is not the case in general.

  1. CAPSULE REPORT: REVERSE OSMOSIS PROCESS

    EPA Science Inventory

    A failure analysis has been completed for the reverse osmosis (RO) process. The focus was on process failures that result in releases of liquids and vapors to the environment. The report includes the following: 1) A description of RO and coverage of the principles behind the proc...

  2. Reversible colour change in Arthropoda.

    PubMed

    Umbers, Kate D L; Fabricant, Scott A; Gawryszewski, Felipe M; Seago, Ainsley E; Herberstein, Marie E

    2014-11-01

    The mechanisms and functions of reversible colour change in arthropods are highly diverse despite, or perhaps due to, the presence of an exoskeleton. Physiological colour changes, which have been recorded in 90 arthropod species, are rapid and are the result of changes in the positioning of microstructures or pigments, or in the refractive index of layers in the integument. By contrast, morphological colour changes, documented in 31 species, involve the anabolism or catabolism of components (e.g. pigments) directly related to the observable colour. In this review we highlight the diversity of mechanisms by which reversible colour change occurs and the evolutionary context and diversity of arthropod taxa in which it has been observed. Further, we discuss the functions of reversible colour change so far proposed, review the limited behavioural and ecological data, and argue that the field requires phylogenetically controlled approaches to understanding the evolution of reversible colour change. Finally, we encourage biologists to explore new model systems for colour change and to engage scientists from other disciplines; continued cross-disciplinary collaboration is the most promising approach to this nexus of biology, physics, and chemistry.

  3. Can luteal regression be reversed?

    PubMed Central

    Telleria, Carlos M

    2006-01-01

    The corpus luteum is an endocrine gland whose limited lifespan is hormonally programmed. This debate article summarizes findings of our research group that challenge the principle that the end of function of the corpus luteum or luteal regression, once triggered, cannot be reversed. Overturning luteal regression by pharmacological manipulations may be of critical significance in designing strategies to improve fertility efficacy. PMID:17074090

  4. Law: Reverse Discrimination, Legal Briefs

    ERIC Educational Resources Information Center

    Nation's Schools and Colleges, 1974

    1974-01-01

    Just as schools and colleges are starting to hire more black and female faculty members through affirmative action programs, there is a new battle cry on the civil rights front: "reverse discrimination." Qualified whites claim they are being shoved aside in the scramble for less-qualified blacks, Chicanos, American Indians, and members of other…

  5. Quotas Are Not Reverse Discrimination

    ERIC Educational Resources Information Center

    McDonald, Gabrielle K.

    1975-01-01

    The findings of the Morrow v. Crisler and NAACP v. Allen civil rights cases are discussed. It is concluded from these employment discrimination cases that quotas are not reverse discrimination because no one has the right to continue to receive the benefits of racial discrimination at the expense of others. (LBH)

  6. An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

    PubMed

    Petit, Damien; Menei, Philippe; Fournier, Henri-Dominique

    2011-11-01

    The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

  7. Supratentorial Neurometabolic Alterations in Pediatric Survivors of Posterior Fossa Tumors

    SciTech Connect

    Rueckriegel, Stefan M.; Driever, Pablo Hernaiz; Bruhn, Harald

    2012-03-01

    Purpose: Therapy and tumor-related effects such as hypoperfusion, internal hydrocephalus, chemotherapy, and irradiation lead to significant motor and cognitive sequelae in pediatric posterior fossa tumor survivors. A distinct proportion of those factors related to the resulting late effects is hitherto poorly understood. This study aimed at separating the effects of neurotoxic factors on central nervous system metabolism by using H-1 MR spectroscopy to quantify cerebral metabolite concentrations in these patients in comparison to those in age-matched healthy peers. Methods and Materials: Fifteen patients with World Health Organization (WHO) I pilocytic astrocytoma (PA) treated by resection only, 24 patients with WHO IV medulloblastoma (MB), who additionally received chemotherapy and craniospinal irradiation, and 43 healthy peers were investigated using single-volume H-1 MR spectroscopy of parietal white matter and gray matter. Results: Concentrations of N-acetylaspartate (NAA) were significantly decreased in white matter (p < 0.0001) and gray matter (p < 0.0001) of MB patients and in gray matter (p = 0.005) of PA patients, compared to healthy peers. Decreased creatine concentrations in parietal gray matter correlated significantly with older age at diagnosis in both patient groups (MB patients, p = 0.009, r = 0.52; PA patients, p = 0.006, r = 0.7). Longer time periods since diagnosis were associated with lower NAA levels in white matter of PA patients (p = 0.008, r = 0.66). Conclusions: Differently decreased NAA concentrations were observed in both PA and MB groups of posterior fossa tumor patients. We conclude that this reflects a disturbance of the neurometabolic steady state of normal-appearing brain tissue due to the tumor itself and to the impact of surgery in both patient groups. Further incremental decreases of metabolite concentrations in MB patients may point to additional harm caused by irradiation and chemotherapy. The stronger decrease of NAA in MB

  8. Superior Labrum Anterior Posterior Lesions and Associated Injuries

    PubMed Central

    Beyzadeoglu, Tahsin; Circi, Esra

    2015-01-01

    Background: Superior labrum anterior posterior (SLAP) lesions often cause shoulder pain, dysfunction, and instability. Professional athletes require a high level of shoulder function for competition and overhead activities. Purpose: To evaluate elite athletes who had arthroscopic surgery for common shoulder pathologies and SLAP lesions with a follow-up of more than 3 years. The associated intra-articular pathologies and return to play were documented. Study Design: Case series; Level of evidence, 4. Methods: Thirty-five shoulders in 34 elite athletes (4 women and 30 men; mean age, 25 years [range, 18-32 years]) had arthroscopic repair of SLAP lesions and accompanying Bankart or rotator cuff tears between January 2008 and November 2011. The documentation included patient symptoms, physical examination, radiological analysis with radiographs, and magnetic resonance imaging. Shoulder function was evaluated preoperatively and at follow-up using American Shoulder and Elbow Surgeons (ASES) and Kerlan Jobe Orthopaedic Clinic (KJOC) scores. The mean follow-up was 52 months. Results: Isolated SLAP lesions were seen in 17.1% of patients, SLAP lesions and partial cuff tear occurred in 25.7%, associated Bankart lesions in 37.1%, full-thickness rotator cuff tears in 8.6%, Bankart and posterior labrum lesions in 8.6%, and Bankart and full-thickness rotator cuff tears in 2.9%. Return to play was a mean 6.4 ± 1.5 months. The mean postoperative ASES and KJOC scores were 89.6 ± 4.6 and 80.9 ± 6.8, respectively, compared with preoperative scores of 64.0 ± 7.2 and 50.5 ± 10.3 (t test, P < .01). Conclusion: The majority (88.2%) of professional athletes returned to their preinjury levels. SLAP lesions may frequently occur with Bankart lesions and rotator cuff tears. A high rate of return to sport at the same level of athletic performance can be achieved by anatomic repair and effective rehabilitation. PMID:26665050

  9. Posterior covariance versus analysis error covariance in variational data assimilation

    NASA Astrophysics Data System (ADS)

    Shutyaev, Victor; Gejadze, Igor; Le Dimet, Francois-Xavier

    2013-04-01

    The problem of variational data assimilation for a nonlinear evolution model is formulated as an optimal control problem to find the initial condition function (analysis) [1]. The data contain errors (observation and background errors), hence there is an error in the analysis. For mildly nonlinear dynamics, the analysis error covariance can be approximated by the inverse Hessian of the cost functional in the auxiliary data assimilation problem [2], whereas for stronger nonlinearity - by the 'effective' inverse Hessian [3, 4]. However, it has been noticed that the analysis error covariance is not the posterior covariance from the Bayesian perspective. While these two are equivalent in the linear case, the difference may become significant in practical terms with the nonlinearity level rising. For the proper Bayesian posterior covariance a new approximation via the Hessian of the original cost functional is derived and its 'effective' counterpart is introduced. An approach for computing the mentioned estimates in the matrix-free environment using Lanczos method with preconditioning is suggested. Numerical examples which validate the developed theory are presented for the model governed by the Burgers equation with a nonlinear viscous term. The authors acknowledge the funding through the Natural Environment Research Council (NERC grant NE/J018201/1), the Russian Foundation for Basic Research (project 12-01-00322), the Ministry of Education and Science of Russia, the MOISE project (CNRS, INRIA, UJF, INPG) and Région Rhône-Alpes. References: 1. Le Dimet F.X., Talagrand O. Variational algorithms for analysis and assimilation of meteorological observations: theoretical aspects. Tellus, 1986, v.38A, pp.97-110. 2. Gejadze I., Le Dimet F.-X., Shutyaev V. On analysis error covariances in variational data assimilation. SIAM J. Sci. Computing, 2008, v.30, no.4, pp.184-1874. 3. Gejadze I.Yu., Copeland G.J.M., Le Dimet F.-X., Shutyaev V. Computation of the analysis error

  10. Metachronous Bilateral Posterior Tibial Artery Aneurysms in Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    Hagspiel, Klaus D.; Bonatti, Hugo; Sabri, Saher; Arslan, Bulent; Harthun, Nancy L.

    2011-04-15

    Ehlers-Danlos syndrome type IV is a life-threatening genetic connective tissue disorder. We report a 24-year-old woman with EDS-IV who presented with metachronous bilateral aneurysms/pseudoaneurysms of the posterior tibial arteries 15 months apart. Both were treated successfully with transarterial coil embolization from a distal posterior tibial approach.

  11. Isolated left posterior insular infarction and convergent roles in verbal fluency, language, memory, and executive function

    PubMed Central

    Ruthirago, Doungporn; DeToledo, John C.

    2016-01-01

    The posterior insular cortex—a complex structure interconnecting various brain regions for different functions—is a rare location for ischemic stroke. We report a patient with isolated left posterior insular infarction who presented with multiple cognitive impairment, including impairment in semantic and phonemic verbal fluency. PMID:27365876

  12. Traumatic bilateral posterior hip dislocation in 10 year old male child.

    PubMed

    Garg, Vipul; Singh, Ajay Pal; Singh, Arun Pal; Bajaj, P S

    2014-09-01

    Traumatic bilateral posterior hip dislocation in skeletally immature patient is reported very less in literature. We report a 10 yr old boy presented to us following farmyard injury with bilateral posterior hip dislocation, which was reduced manually under sedation with uneventful follow-up and complete hip range of motion at 2 year. PMID:25983489

  13. Editorial Commentary: Posterior Cruciate Ligament Reconstruction--Do Not Abandon the C-Arm Quite Yet.

    PubMed

    Hunt, Timothy J

    2016-03-01

    Accurate tibial tunnel placement using the arthroscopically-assisted anatomic fovea landmark technique in transtibial posterior cruciate ligament reconstruction is possible without the use of fluoroscopic imaging. However, until a prospective, randomized controlled trial comparing the C-arm and anatomic fovea landmark techniques is completed, abandonment of the C-arm in posterior cruciate ligament reconstruction cannot be recommended.

  14. Posterior resin-based composite restorations: clinical recommendations for optimal success.

    PubMed

    Ritter, A V

    2001-01-01

    Resin-based composites are increasingly used for the restoration of defects in posterior teeth. This review describes, illustrates and discusses important clinical aspects of the posterior composite technique. A relatively new stratification concept oriented to the development of functional and anatomic restorations is proposed.

  15. 21 CFR 872.3900 - Posterior artificial tooth with a metal insert.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Posterior artificial tooth with a metal insert. 872.3900 Section 872.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3900 Posterior...

  16. 21 CFR 872.3900 - Posterior artificial tooth with a metal insert.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Posterior artificial tooth with a metal insert. 872.3900 Section 872.3900 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3900 Posterior...

  17. Reinterpretation of O'Brien test in posterior labral tears of the shoulder

    PubMed Central

    Owen, J. Matthew; Boulter, Thomas; Walton, Mike; Funk, Lennard; Mackenzie, Tanya Anne

    2015-01-01

    Background: Injuries to the posterior labrum are less common and more difficult to diagnose compared to anterior labral pathology. This may be in part due to difficulties in preoperative diagnosis. Posterior labral injuries cause abnormal loading of the rotator cuff with subsequent weakness. Examination using the O'Briens test tightens the posterior capsule and posteriorly translates the humeral head, stressing the labrum resulting in pain and weakness. Method: A retrospective study. Results: Of 74 patients diagnosed with a posterior labral tear at arthroscopy 55 had subjective weakness on performing a O'Briens test, a sensitivity of 83% and a positive predictive value (PPV) of 90%. Conclusion: Multiple tests have been described for posterior labral pathology and none of these, on their own, have a high sensitivity rate. Posterior labral injuries can often be missed on magnetic resonance imaging scanning and also at surgery if not specifically looked for. Using a sign of clinically demonstrated weakness when performing the O'Briens test, and hence reinterpretation of the test, is sensitive, with a high PPV for posterior labral pathology and can help guide further treatment. PMID:25709238

  18. Improvising a Posterior Nasal Pack with Equipment in a Basic First Aid Kit.

    PubMed

    Royer, Allison K; Royer, Mark C

    2016-09-01

    Posterior epistaxis is a serious condition that can be difficult to treat in a wilderness setting. The initial standard of care involves packing the affected nostril with a 7 to 9 cm nasal pack to tamponade the bleed. These packs are often unavailable outside of the emergency or operating room. This study set out to determine whether a posterior nasal pack could be constructed from the supplies present in a basic first aid kit in order to control massive nasal hemorrhage in a wilderness setting. A basic first aid kit was utilized to construct a posterior nasal pack that was inserted into an anatomical model and visibly compared with the Rapid Rhino (Posterior, 7.5 cm; Smith & Nephew, Austin, TX) nasal packing. The shape, size, and anatomical areas of compression (ie, into nasopharynx and posterior aspect of inferior turbinate) of this pack was similar to the commercially available posterior nasal pack. Placement in an anatomical model appears to provide similar compression as the commercially available posterior pack. This technique may provide short-term hemorrhage control in cases of serious posterior nasal hemorrhage where standard treatment options are not available. PMID:27473927

  19. Perception of Place of Articulation by Children with Cleft Palate and Posterior Placement.

    ERIC Educational Resources Information Center

    Whitehill, Tara L.; Francis, Alexander L.; Ching, Christine K-Y.

    2003-01-01

    A study examined if 10 children (ages 4-12) with repaired cleft palate who demonstrate posterior placement of alveolar targets differed from 10 children with cleft palate without such error patterns, and from 10 controls in the perception of alveolar targets. Children with posterior placement appeared unable to distinguish alveolar targets.…

  20. Isolated posterior dislocation of the radial head without fracture of the ulna in a child.

    PubMed

    Wouters, E; Fortems, Y; Mulier, E; Stuyck, J; Fabry, G

    1993-01-01

    An isolated posterior dislocation of the radial head is a rare injury. We present a case report on an 11-year-old boy with a traumatic posterior radial head dislocation without fracture or bending of the ulna. The diagnosis can be difficult and should be supported with good radiographic images, since clinically the injury can be missed or misdiagnosed. PMID:8484316