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  1. Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Algahtani, Abdulhadi; Aldarmahi, Ahmad; Hmoud, Mohammed; Marzuk, Yousef; Shirah, Bader

    2016-01-01

    Objectives: Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological syndrome characterized by headache, altered mental status, seizures, or loss of vision. In this study, we report the largest series of PRES coming from Saudi Arabia and explore the etiology, clinical presentation, and outcome. We also report new imaging findings associated with this condition. Methods: We performed a retrospective study of all cases of PRES admitted to King Abdulaziz Medical City, Jeddah, Saudi Arabia, between the years 2005 and 2015. A neurologist reviewed all charts and analyzed the clinical presentations, etiological factors, and outcomes, and a neuroradiologist reviewed the imaging studies. Only patients with clinical and imaging features consistent with PRES were included in the study. Results: We collected 31 patients who had clinical and radiological features consistent with PRES. Females were more affected than males (18 females and 13 males), and patients’ age ranged from 6 to 95 years, with a mean of 38.3 years. Patients were treated by removing the precipitating causes and treating the underlying conditions. Resolution of neurologic signs occurred within 2 to 3 weeks in all patients. Conclusion: In our opinion, PRES itself is usually a benign condition with complete recovery if the condition is recognized early and managed appropriately. Although clinical signs are nonspecific, the constellation of symptoms including headache, visual problems, seizures, and altered level of consciousness should suggest the possibility of PRES, especially in high-risk group. Abnormalities on magnetic resonance imaging are often characteristic and may be the first clue to the diagnosis. PMID:28042366

  2. Reversible cortical blindness: posterior reversible encephalopathy syndrome.

    PubMed

    Bandyopadhyay, Sabyasachi; Mondal, Kanchan Kumar; Das, Somnath; Gupta, Anindya; Biswas, Jaya; Bhattacharyya, Subir Kumar; Biswas, Gautam

    2010-11-01

    Cortical blindness is defined as visual failure with preserved pupillary reflexes in structurally intact eyes due to bilateral lesions affecting occipital cortex. Bilateral oedema and infarction of the posterior and middle cerebral arterial territory, trauma, glioma and meningioma of the occipital cortex are the main causes of cortical blindness. Posterior reversible encephalopathy syndrome (PRES) refers to the reversible subtype of cortical blindness and is usually associated with hypertension, diabetes, immunosuppression, puerperium with or without eclampsia. Here, 3 cases of PRES with complete or partial visual recovery following treatment in 6-month follow-up are reported.

  3. [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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26515750

  5. 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.

  6. Reversible posterior leucoencephalopathy syndrome associated with bone marrow transplantation.

    PubMed

    Teive, H A; Brandi, I V; Camargo, C H; Bittencourt, M A; Bonfim, C M; Friedrich, M L; de Medeiros, C R; Werneck, L C; Pasquini, R

    2001-09-01

    Reversible posterior leucoencephalopathy syndrome (RPLS) has previously been described in patients who have renal insufficiency, eclampsia, hypertensive encephalopathy and patients receiving immunosuppressive therapy. The mechanism by which immunosuppressive agents can cause this syndrome is not clear, but it is probably related with cytotoxic effects of these agents on the vascular endothelium. We report eight patients who received cyclosporine A (CSA) after allogeneic bone marrow transplantation or as treatment for severe aplastic anemia (SSA) who developed posterior leucoencephalopathy. The most common signs and symptoms were seizures and headache. Neurological dysfunction occurred preceded by or concomitant with high blood pressure and some degree of acute renal failure in six patients. Computerized tomography studies showed low-density white matter lesions involving the posterior areas of cerebral hemispheres. Symptoms and neuroimaging abnormalities were reversible and improvement occurred in all patients when given lower doses of CSA or when the drug was withdrawn. RPLS may be considered an expression of CSA neurotoxicity.

  7. Management of Posterior Reversible Syndrome in Preeclamptic Women

    PubMed Central

    Poma, S.; Delmonte, M. P.; Gigliuto, C.; Imberti, R.; Delmonte, M.; Arossa, A.; Iotti, G. A.

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological syndrome associated with a number of conditions including preeclampsia. It is characterized by seizures, alteration of consciousness, visual disturbances, and symmetric white matter abnormalities, typically in the posterior parietooccipital regions of the cerebral hemispheres, at computed tomography (CT) and magnetic resonance (MRI). We report three new cases of PRES in preeclamptic patients and describe the management of these patients. We present a brief review of other cases in the literature, with particular attention to the anesthetic management. PMID:25506009

  8. Posterior reversible encephalopathy syndrome associated with left horizontal gaze palsy

    PubMed Central

    Studyvin, Sarah; Al-Halawani, Moh’d; Amireh, Sawsan; Thawabi, Mohammad

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by rapid onset of symptoms including headache, seizures, altered consciousness, and visual disturbance, as well as radiologic findings of focal reversible vasogenic edema. Multiple visual disturbances have been described in PRES, such as hemianopia, visual neglect, auras, visual hallucinations, and cortical blindness. However, horizontal gaze palsy has not been previously reported. We report a 72-year-old female who presented with blurred vision, severe headache, lethargy, and later developed seizures. She was found to have left horizontal gaze palsy with intact vestibulo-ocular reflex. Brain magnetic resonance imaging (MRI) showed severe edema throughout the subcortical white matter, and signal in the posterior parietal and occipital lobes. She was diagnosed with PRES associated with supranuclear gaze palsy. PMID:28361069

  9. Epinephrine-induced posterior reversible encephalopathy syndrome: a case report.

    PubMed

    Gharabawy, Ramez; Pothula, Vijayasimha R; Rubinshteyn, Vladimir; Silverberg, Michael; Gave, Asaf A

    2011-09-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare disorder that is usually associated with hypertensive crises. It is often missed but may be diagnosed by head computed tomographic (CT) scan or magnetic resonance imaging. An adolescent man presented for elective right shoulder arthroscopic bankart repair. Arthroscopy was performed using a solution of normal saline with 3.3 mg/L of epinephrine for irrigation. Postoperatively, the patient presented with hypertension and epileptiform activity. A CT scan of the head showed PRES.

  10. Posterior reversible encephalopathy syndrome in children: a case series

    PubMed Central

    Emeksiz, Serhat; Kutlu, Nurettin Onur; Çaksen, Hüseyin; Alkan, Gülsüm; Yıkmaz, Hülya Şeker; Tokgöz, Hüseyin

    2016-01-01

    Posterior reversible encephalopathy syndrome is characterized by hypertension, seizure, headache, clouding of consciousness, and visual disturbance, and is diagnosed in the presence of typical lesions on magnetic resonance imaging. We retrospectively evaluated five patients who were diagnosed as having posterior reversible encephalopathy syndrome and followed up in Meram Medical Faculty, Pediatric Intensive Care and Hematology wards, between January 2010 and January 2014. We reviewed the demographic and clinical data, and neuroimaging findings. The primary diseases of the subjects included acute lymphocytic leukemia (n=2), Henoch-Schönlein purpura (n=1), systemic lupus erythematous (n=1), and acute poststreptococcal glomerulonephritis (n=1). The mean age was 10±4.58 years (range, 5–14 years). Acute elevation of blood pressure was found in all patients (n=5). Initial neurologic manifestations included seizure, clouding of consciousness, headache, and visual disturbance. After the diagnosis was made through clinical evaluations and magnetic resonance imaging, complete clinical recovery was obtained in all patients with the appropriate therapeutic approach. In conclusion, posterior reversible encephalopathy syndrome should be considered in the differential diagnosis of patients who present with encephalopathy and underlying diseases such as nephritis, vasculitis, malignancy accompanied by hypertension, and a history of use of medication. PMID:28123335

  11. Posterior reversible encephalopathy syndrome following a scorpion sting.

    PubMed

    Porcello Marrone, Luiz Carlos; Marrone, Bianca Fontana; Neto, Felipe Kalil; Costa, Francisco Cosme; Thomé, Gustavo Gomes; Aramburu, Martin Brandolt; Schilling, Lucas Porcello; Pascoal, Tharick Ali; Gadonski, Giovani; Huf Marrone, Antônio Carlos; da Costa, Jaderson Costa

    2013-10-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity not yet understood, that is present with transient neurologic symptoms and particular radiological findings. The most common imaging pattern in PRES is the presence of edema in the white matter of the posterior portions of both cerebral hemispheres. The cause of PRES is unclear. We report a case of 13-year-old male who was stung by a scorpion and developed a severe headache, visual disturbance, and seizures and had the diagnosis of PRES with a good outcome. Numerous factors can trigger this syndrome, most commonly: acute elevation of blood pressure, abnormal renal function, and immunosuppressive therapy. There are many cases described showing the relationship between PRES and eclampsia, transplantation, neoplasia and chemotherapy treatment, systemic infections, renal disease acute, or chronic. However, this is the first case of PRES following a scorpion sting.

  12. A reversible posterior leucoencephalopathy syndrome including blindness caused by preeclampsia

    PubMed Central

    Vandenbossche, G; Maquet, J; Vroonen, P; Lambert, G; Nisolle, M; Kridelka, F; Emonts, E

    2016-01-01

    Complications of (pre)eclampsia may involve multiple systems and organs. Neurological symptoms may occur. Visual symptoms concern up to 25% the of patients with severe preeclampsia and 50% of the patients with eclampsia. An uncommon effect of severe preeclampsia is sudden blindness. Blindness may be part of a clinical and radiological presentation named Posterior Reversible Encephalopathy Syndrome (PRES). PRES may lead to permanent neurological deficit, recurrences or death. We report the case of a 24-year-old Caucasian patient, gravida 5 para 2 who developed preeclampsia and PRES complicated with blindness at 32 weeks of gestation. Optimal care allowed visual symptoms to resolve within 24 hours and a favourable maternal outcome and no long- term sequelae. We describe different causes and manifestations of PRES and highlight the need for immediate care in order to optimize the chance of symptoms reversibility. PMID:28003872

  13. Acute Pancreatitis and Posterior Reversible Encephalopathy Syndrome: A Case Report.

    PubMed

    Magno Pereira, Vítor; Marote Correia, Luís; Rodrigues, Tiago; Serrão Faria, Gorete

    2016-09-01

    The posterior reversible encephalopathy syndrome is a neurological syndrome characterized by headache, confusion, visual disturbances and seizures associated with identifiable areas of cerebral edema on imaging studies. The authors report the case of a man, 33 years-old, leukodermic with a history of chronic alcohol and tobacco consumption, who is admitted to the emergency department for epigastric pain radiating to the back and vomiting with about six hours of evolution and an intense holocranial headache for two hours. His physical examination was remarkable for a blood pressure of 190/100 mmHg and tenderness in epigastrium. His analytical results revealed emphasis on amylase 193 U/L and lipase 934 U/L. During the observation in the emergency department,he presented a generalized tonic-clonic seizure. Abdominal ultrasonography was performed and suggestive of pancreatitis withoutgallstones signals. Head computed tomography showed subarachnoid haemorrhage and a small right frontal cortical haemorrhage. The brain magnetic resonance imaging done one week after admission showed areas of a bilateral and symmetrical T2 / FLAIR hyperintensities in the subcortical white matter of the parietal and superior frontal regions, suggesting a diagnosis of posterior reversible encephalopathy syndrome. Abdominal computed tomography (10 days after admission) demonstrated a thickened pancreas in connection with inflammation and two small hypodense foci in the anterior part of the pancreas body, translating small foci of necrosis. The investigation of a thrombophilic defect revealed a heterozygous G20210A prothrombin gene mutation. The patient was discharged without neurological sequelae and asymptomatic. The follow-up brain magnetic resonance imaging confirmed the reversal of the lesions, confirming the diagnosis.

  14. Posterior reversible encephalopathy syndrome caused by presumed Takayasu arteritis

    PubMed Central

    Lee, Ki Wuk; Lee, Sang Taek

    2016-01-01

    Takayasu arteritis (TA) is a chronic inflammatory disease of unknown etiology that affects mainly the aorta, main aortic branches, and pulmonary arteries. Diverse neurological manifestations of TA have rarely been reported in children. Posterior reversible encephalopathy syndrome (PRES) is a neuroradiological condition that presents with headache, seizure, visual disturbances, and characteristic lesions on imaging. Inflammatory condition and severe hypertension in TA can cause PRES. We report of a 5-year-old girl with presumed TA who presented with PRES and chronic total occlusion in the renal artery. The findings on magnetic resonance imaging suggested PRES. Left nephrectomy was performed for total occlusion of the left renal artery, and the confirmatory diagnosis of TA was based on the pathologic findings of the renal artery. PMID:28018468

  15. Permanent bilateral cortical blindness due to reversible posterior leukoencephalopathy syndrome.

    PubMed

    Iwama, Mayumi; Takahashi, Hiroshi; Takagi, Ryo; Hiraoka, Miki

    2011-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is induced by acute cerebral edema. Its symptoms include seizures, headache, altered mental status, and visual disturbances. The clinical and radiological findings are usually transient. This report describes a case of RPLS resulting in bilateral total blindness. A 40-year-old man presented with lethargy and bilateral visual loss. He had a 20-year history of hypertension, but had never been treated. On presentation, the left eye was able to perceive light, but the right eye was not. Radiological examination showed diffuse edema in the brain, and ocular fundus examination revealed severe bilateral hypertensive retinopathy. Antihypertensive therapy improved the patient's general condition, including blood pressure. Radiological findings 5 months later showed resolution of most of the abnormal signal areas. However, total blindness had developed in both eyes by day 15, and two courses of pulsed corticosteroid therapy failed to restore the visual loss.

  16. Acute cortical blindness due to posterior reversible encephalopathy.

    PubMed

    Nguyen-Lam, Jenny; Kiernan, Matthew C

    2008-10-01

    An acutely hypertensive 55 year-old male experienced seizures and cortical blindness post-operatively. CT scans demonstrated hypointensities in the occipital lobes bilaterally. MRI revealed symmetrical bilateral hyperintense signals in the same region, involving both grey and white matter. Thromboembolic screening investigations including vertebral artery doppler studies were normal and echocardiography demonstrated borderline left ventricular hypertrophy. A diagnosis of posterior reversible encephalopathy syndrome (PRES) was reached and there was complete resolution of blindness with antihypertensive therapy. This case supports the vasogenic theory of PRES which suggests that sustained high grade fluctuations in blood pressure lead to a reduction in cerebral vascular autoregulatory function. The resultant failure of compensatory vasoconstriction to prevent hyperperfusion causes fluid to extravasate into the occipital lobes, which in the present case resulted in cortical blindness.

  17. [Posterior Reversible Encephalopathy Syndrome Associated with Cancer Therapy].

    PubMed

    Mitsuya, Koichi; Nakasu, Yoko; Hayashi, Nakamasa; Yasui, Hirofumi; Ikeda, Takashi; Kuji, Shiho; Onozawa, Yusuke; Endo, Masahiro

    2016-03-01

    Posterior reversible encephalopathy syndrome(PRES)is a subacute neurological syndrome typically manifesting with headache, cortical blindness, and seizures. This syndrome is associated with risk factors such as malignant hypertension, eclampsia, and renal failure. Numerous case reports depict its occurrence in cancer patients. The direct causal mechanisms of PRES in cancer patients have not yet been identified. Cytotoxic chemotherapy may cause direct endothelial damage, which would impact the blood brain barrier. Angiogenesis inhibitors also cause elevation in blood pressure;this is significant, because PRES onset may be solely related to hypertension. An increased number of case reports involving new molecular targeted agent suggests that incidence of PRES as an oncological emergency may increase in the future.

  18. Neuropathology of a fatal case of posterior reversible encephalopathy syndrome.

    PubMed

    Kheir, John N; Lawlor, Michael W; Ahn, Edward S; Lehmann, Leslie; Riviello, James J; Silvera, V Michelle; McManus, Michael; Folkerth, Rebecca D

    2010-01-01

    The pathology of posterior reversible encephalopathy syndrome (PRES) is undefined, since it is rarely fatal and is biopsied in only exceptional circumstances. We describe rapidly progressive PRES following stem cell transplant for acute lymphoblastic leukemia. After development of altered mental status, this 8-year-old girl had T2 prolongation of the white matter in a posterior-dominant distribution, eventually developing cerebellar edema, hemorrhage, hydrocephalus, and herniation. Despite surgical and medical management, she died 36 hours later. At autopsy, the occipital and cerebellar white matter and focal occipital cortical gray matter showed a spectrum of microvascular changes, including dilated perivascular spaces containing proteinaceous exudates and macrophages, as well as fibrinoid necrosis and acute hemorrhage, in a distribution corresponding to the neuroimaging abnormalities and reminiscent of those seen in patients with acute hypertensive encephalopathy. Of note, similar microvascular changes were not seen in the kidney or other systemic sites. Thus, the findings indicate a brain-specific microvascular compromise as the substrate of PRES, at least in the rare instance of cases progressing to fatal outcome.

  19. Study of Posterior Reversible Encephalopathy Syndrome in Children With Acute Lymphoblastic Leukemia After Induction Chemotherapy.

    PubMed

    Tang, Ji-Hong; Tian, Jian-Mei; Sheng, Mao; Hu, Shao-Yan; Li, Yan; Zhang, Li-Ya; Gu, Qing; Wang, Qi

    2016-03-01

    Increasing occurrence of posterior reversible encephalopathy syndrome has been reported in children with acute lymphoblastic leukemia. However, the etiology of posterior reversible encephalopathy syndrome is not clear. To study the possible pathogenetic mechanisms and treatment of this complication, we reported 11 cases of pediatric acute lymphoblastic leukemia who developed posterior reversible encephalopathy syndrome after induction chemotherapy. After appropriate treatment, the clinical symptoms of posterior reversible encephalopathy syndrome in most cases disappeared even though induction chemotherapy continued. During the 1-year follow-up, no recurrence of posterior reversible encephalopathy syndrome was observed. Although the clinical and imaging features of posterior reversible encephalopathy syndrome may be diverse, posterior reversible encephalopathy syndrome should be recognized as a possible important complication of acute lymphoblastic leukemia when neurologic symptoms appear. In line with previous reports, our study also indicated that posterior reversible encephalopathy syndrome was reversible when diagnosed and treated at an early stage. Thus, the occurrence of posterior reversible encephalopathy syndrome should be considered and investigated to optimize the early induction scheme of acute lymphoblastic leukemia treatment.

  20. Posterior reversible encephalopathy syndrome (PRES) and hypomagnesemia: A frequent association?

    PubMed

    Chardain, A; Mesnage, V; Alamowitch, S; Bourdain, F; Crozier, S; Lenglet, T; Psimaras, D; Demeret, S; Graveleau, P; Hoang-Xuan, K; Levy, R

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a serious neurological condition encountered in various medical fields. Pathophysiological factor(s) common to PRES cases of apparently unrelated etiologies are yet to be found. Based on the hypothesis that hypomagnesemia might participate in the cascade leading to PRES, our study sought to verify whether hypomagnesemia is frequently associated with PRES regardless of etiology. From a retrospective study of a cohort of 57 patients presenting with PRES of different etiologies, presented here are the findings of 19 patients with available serum magnesium levels (SMLs) during PRES. In the acute phase of PRES, hypomagnesemia was present in all 19 patients in spite of differences in etiology (including immunosuppressive drugs, hypertensive encephalopathy, eclampsia, systemic lupus erythematosus, iatrogenic etiology and unknown). SMLs were within normal ranges prior to PRES and below normal ranges during the first 48h of PRES, with a significant decrease in SMLs during the acute phase. In this retrospective study, constant hypomagnesemia was observed during the acute phase of PRES regardless of its etiology. These results now require larger studies to assess the particular importance of acute hypomagnesemia in PRES and especially the possible need to treat PRES with magnesium sulfate.

  1. [Reversible posterior leukoencephalopathy syndrome associated with carbamazepine-induced hypertension].

    PubMed

    Furuta, Natsumi; Fujita, Yukio; Sekine, Akiko; Ikeda, Masaki; Okamoto, Koichi

    2009-04-01

    A 21-year-old man developed idiopathic trigeminal neuralgia, and was admitted to our hospital. Although neuralgia was promptly resolved after oral carbamazepine (CBZ) administration, he developed arterial hypertension (from 110/60 mmHg to 170/126 mmHg) followed by consciousness disturbance several days after the initiation of carbamazepine. MRI T2-weighted, FLAIR and ADC images demonstrated transient hyperintense lesions of the bilateral fronto-parieto-occipital subcortical white matter. These lesions showed isointensity on diffusion-weighted images. Since these alterations suggested the presence of vasogenic edema induced by hypertension, we diagnosed him as having reversible posterior leukoencephalopathy syndrome (RPLS) induced by hypertension. Persistent hypertension despite the administration of various anti-hypertension drugs finally improved after oral CBZ therapy was discontinued. Therefore, we considered that hypertension was induced by oral CBZ therapy. This is a rare case in which high blood pressure was caused by CBZ. There is no previous report of RPLS induced by CBZ administration. Further investigation to determine whether CBZ is capable of causing arterial hypertension is warranted.

  2. 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.

  3. 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.

  4. Posterior reversible encephalopathy syndrome is not associated with mutations in aquaporin-4.

    PubMed

    Matiello, Marcelo; Muralidharan, Rajanandini; Sun, David; Rabinstein, Alejandro A; Weinshenker, Brian G

    2015-08-01

    Posterior reversible encephalopathy syndrome (PRES) is characterized by acute reversible subcortical vasogenic edema that is typically bilateral and self-limiting. It preferentially affects posterior regions of the brain. Clinical manifestations include encephalopathy, seizures, headache, and cortical blindness. PRES may be precipitated by hypertensive crises such as eclampsia and by immunosuppressive agents. The pathophysiology of PRES is incompletely understood. Disordered cerebral autoregulation leading to protein and fluid extravasation is thought to be important.(1) Other theories implicate endothelial dysfunction or vasospasm.(2).

  5. Reversible posterior leukoencephalopathy syndrome in children with nephrotic syndrome: a case report.

    PubMed

    Liu, Sheng-da; Shen, Qing-min; Lv, Chun-feng

    2014-03-01

    REVERSIBLE posterior leukoencephalopathy syndrome (RPLS) is a rare neurological syndrome characterized by headache, altered mental status, seizures, and visual disturbance, associated with reversible white matter changes.1 It has been commonly reported in patients with severe hypertension and pre-eclampsia. Here we report a case with nephrotic syndrome complicated by RPLS.

  6. Posterior Reversible Encephalopathy Syndrome in a Postpartum Preeclamptic Woman without Seizure

    PubMed Central

    Ural, Ülkü Mete; Balik, Gülsah; Şentürk, Şenol; Üstüner, Işık; Çobanoğlu, Uğur; Şahin, Figen Kır

    2014-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a cliniconeuroradiological entity presenting with headache, confusion, visual disturbances or blindness, and seizures. Parieto-occipital white matter changes due to vasogenic oedema can be observed on imaging modalities. It rarely occurs without seizures and after delivery. We report a 33-year-old multigravida with a history of preeclampsia in term pregnancy complicated by PRES without seizures at the postpartum period. Clinical improvement with complete resolution without any complications was observed on the 6th day after delivery. Posterior reversible encephalopathy syndrome is reversible when early diagnosis is established and appropriate treatment is started without delay. PMID:24592342

  7. Posterior Reversible Encephalopathy Syndrome with Extensive Deep White Matter Lesions Including the Temporal Pole

    PubMed Central

    Ohira, Junichiro; Mori, Nobuyuki; Kajikawa, Shunsuke; Nakamura, Takeshi; Arisato, Tetsuya; Takahashi, Makio

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) typically affects the posterior subcortical white matter. We report the case of a 55-year-old man with atypical PRES, who had malignant hypertension and renal dysfunction. Magnetic resonance imaging of the brain revealed extensive vasogenic edema in the deep white matter including the temporal pole, as well as in the brainstem and cerebellum. Antihypertensive therapy and hemodialysis contributed to both clinical and radiological improvement. Involvement of the deep white matter including the temporal pole, which is rarely affected in an ischemic stroke, should be recognized as a potential sign of PRES. PMID:27904123

  8. The reverse Segond fracture: not associated with knee dislocation and rarely with posterior cruciate ligament tear.

    PubMed

    Peltola, Erno K; Lindahl, Jan; Koskinen, Seppo K

    2014-06-01

    The aims of this study were to assess the incidence of reverse Segond fracture, to examine the associated ligamentous injuries, and to examine how often reverse Segond fracture coexists with a knee dislocation. At a level 1 trauma center, an 11-year period of emergency department multidetector-row computed tomography (MDCT) examinations for knee trauma was evaluated for reverse Segond and Segond fractures. Surgical findings served as the reference standard for intra-articular injuries. The hospital discharge register was searched for the diagnosis of knee dislocation from August 2000 through the end of August 2011. A total of 1,553 knee MDCT examinations were evaluated. Ten patients with a reverse Segond fracture were found, comprising 0.64 % of emergency room acute knee trauma MDCT examinations. Seven patients who had a reverse Segond fracture were operated: Three had an avulsion fracture of the anterior cruciate ligament, one had an avulsion fracture of posterior cruciate ligament, two had a lateral meniscal tear, and two had a medial collateral ligament tear. The ratio of reverse Segond fractures to Segond fractures was 1:4. None of the 71 knee dislocation patients had a reverse Segond fracture. Reverse Segond fracture is a rare finding even in a level 1 trauma center. Cruciate ligament injuries appear to be associated with avulsion fracture, but every patient does not have PCL injury, as previously reported. Our results do not support the association of knee dislocation with reverse Segond fracture.

  9. Recurarization in a successfully managed case of posterior reversible encephalopathy syndrome (PRES) for emergency caesarean section

    PubMed Central

    Parikh, Suchita; Tavri, Snehlata; Mohite, Shubha

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic syndrome of headache, visual changes, altered mental status and seizures with radiologic findings of posterior cerebral white matter edema. It is seen in hypertensive encephalopathy, renal failure, and autoimmune disorders or in patients on immunosuppressants. We report a case of 24-year-old primigravida who presented at term with sudden onset hypertension, neurological deficits, and an episode of the visual blackout. Magnetic resonance imaging showed features suggestive of PRES. She was posted for emergency lower segment cesarean section. General anesthesia was administered and blood pressure managed with antihypertensives. Postoperatively, she developed acute respiratory depression after prophylactic administration of injection magnesium sulfate. This case highlights that good clinical acumen along with early neuroimaging helps in prompt diagnosis, treatment and prevention of long-term neurological sequelae in PRES and the anesthetic implications of administering magnesium sulfate in the immediate post neuromuscular block reversal phase. PMID:27212776

  10. [Prolonged cerebral salt wasting following craniopharyngioma surgery and posterior reversible encephalopathy syndrome: a case report].

    PubMed

    Ohtonari, Tatsuya; Hashimoto, Masanori; Urasaki, Eiichiro; Yokota, Akira; Araki, Shunsuke; Asayama, Koutaro; Shirahata, Akira

    2005-01-01

    A 9-year-old boy was admitted to our hospital with daytime urinary incontinence for the past one year. MRI showed craniopharyngioma occupying the third ventricle. The tumor was excised by interhemispheric approach. Because hyponatremia and polyuria with high renal loss of sodium were observed on postoperative day 3, hydrocortisone and DDAVP were replaced. On postoperative day 24, successive general convulsions and hyponatremia recurred, and MRI FLAIR imaging showed marked brain edema in the bilateral parieto-occipital lobes. This finding disappeared late in the course of treatment, and the case was diagnosed as posterior reversible encephalopathy syndrome. The pathophysiology of cerebral salt wasting and posterior reversible encephalopathy syndrome in a craniopharyngioma patient are also discussed in the article.

  11. Posterior reversible encephalopathy syndrome--Insight into pathogenesis, clinical variants and treatment approaches.

    PubMed

    Granata, Guido; Greco, Antonio; Iannella, Giannicola; Granata, Massimo; Manno, Alessandra; Savastano, Ersilia; Magliulo, Giuseppe

    2015-09-01

    Posterior reversible encephalopathy syndrome is a rare clinicoradiological entity characterized by typical MRI findings located in the occipital and parietal lobes, caused by subcortical vasogenic edema. It was first described as a distinctive syndrome by Hinchey in 1996. Etiopathogenesis is not clear, although it is known that it is an endotheliopathy of the posterior cerebral vasculature leading to failed cerebral autoregulation, posterior edema and encephalopathy. A possible pathological activation of the immune system has been recently hypothesized in its pathogenesis. At clinical onset, the most common manifestations are seizures, headache and visual changes. Besides, tinnitus and acute vertigo have been frequently reported. Symptoms can be reversible but cerebral hemorrhage or ischemia may occur. Diagnosis is based on magnetic resonance imaging, in the presence of acute development of clinical neurologic symptoms and signs and arterial hypertension and/or toxic associated conditions with possible endotheliotoxic effects. Mainstay on the treatment is removal of the underlying cause. Further investigation and developments in endothelial cell function and in neuroimaging of cerebral blood flow are needed and will help to increase our understanding of pathophysiology, possibly suggesting novel therapies.

  12. Posterior reversible encephalopathy syndrome after intrathecal methotrexate infusion: a case report and literature update

    PubMed Central

    Pavlou, Evangelos; Anastasiou, Athanasia; Pana, Zoi; Tsotoulidou, Vasiliki; Kinali, Maria; Hatzipantelis, Emmanuel

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare clinical-radiological entity characterised by seizures, severe headache, mental status instability and visual disturbances. Hypertension is typically present. We report a case of a 13-year old boy with Burkitt lymphoma/leukaemia, who presented with posterior leukoencephalopathy 24 hours after intrathecal methotrexate (MTX) infusion. The child presented with headache, seizures, elevated blood pressure and gradual deterioration of his neurological status. Midazolam, dexamethazone and furosemide were initiated leading to reduction of cerebral oedema and clinical improvement. A thorough literature review is discussed in this report. Pathophysiology of leukoencephalopathy remains unclear. It develops within 5–14 days after intrathecal MTX and resolves within a week usually without permanent neurological sequelae. Broad use of MRI has led to an increasing number of identified cases of PRES. Treatment approach is mainly to manage the underlying cause of PRES. Prognosis is generally benign; however delayed diagnosis and improper management may result in permanent brain insult. PMID:27942481

  13. Cortical blindness and posterior reversible encephalopathy syndrome in an older patient.

    PubMed

    Ait, Sabrina; Gilbert, Thomas; Cotton, Francois; Bonnefoy, Marc

    2012-05-26

    Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological entity. It associates, to varying extents, neurological symptoms such as headaches, confusion, seizures and visual alterations from haemianopsia to cortical blindness. The diagnosis relies on brain MRI, showing signs of subcortical and cortical oedema in the posterior regions of the brain, with hypersignals in T2/fluid attenuated inversion recovery (FLAIR) or diffusion sequences. With early diagnosis and control of the causal factors, the symptoms and radiological signs can be - as the name implies - totally regressive. PRES can be caused by various heterogeneous factors, such as hypertension, side effect of drug therapies, eclampsia, sepsis or autoimmune diseases. The authors report here the case of an 86-year-old woman, presenting totally regressive cortical blindness and seizures, with compatible imaging.

  14. 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

  15. 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. PMID:27322924

  16. 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

  17. Posterior reversible encephalopathy syndrome in patient of severe preeclampsia with Hellp syndrome immediate postpartum.

    PubMed

    Babahabib, Moulay Abdellah; Abdillahi, Ibrahima; Kassidi, Farid; Kouach, Jaouad; Moussaoui, Driss; Dehayni, Mohammed

    2015-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a rare clinico-neuroradiologic condition, not commonly reported in the literature. PRES is an uncommon complication of severe preeclampsia/eclampsia. We report the management of one patient with postpartum preeclampsia as an association of HELLP syndrome presenting with status-epileptics. Early diagnosis along with timely supportive therapy resulted in the successful management of this challenging case. Recent understanding on the pathophysiology of this uncommon condition is discussed. We highlight the importance to obstetricians, intensive-care physicians and anesthesiologists of recognizing such cases.

  18. Cortical visual loss in posterior reversible encephalopathy syndrome in late postpartum eclampsia: case series.

    PubMed

    Karuppannasamy, Divya; Vikrant, K; Raghuram, A; Kumaar, T M Sathish

    2014-05-01

    The purpose of this study was to determine the prevalence of visual disturbances in patients with posterior reversible encephalopathy syndrome (PRES) associated with late postpartum eclampsia. We retrospectively reviewed the clinical records of late postpartum eclampsia patients with features of PRES for the presence of visual disturbances and location of radiological abnormalities. We found a higher prevalence of cortical visual loss in patients with PRES associated with late postpartum eclampsia. Bilateral symmetrical vasogenic edema of the parieto-occipital lobe was the most common magnetic resonance imaging (MRI) abnormality noted. No significant differences were observed in the extent of edema in patients with and without visual loss.

  19. Posterior reversible encephalopathy syndrome complicating diabetic ketoacidosis; an important treatable complication.

    PubMed

    Jones, Rachel; Redler, Kasey; Witherick, Jonathan; Fuller, Geraint; Mahajan, Tripti; Wakerley, Benjamin R

    2017-03-01

    Development of acute neurological symptoms secondary to cerebral oedema is well described in diabetic ketoacidosis (DKA) and often has a poor prognosis. We present the clinical and radiological data of a 17-yr-old girl who developed cortical blindness, progressive encephalopathy, and seizures caused by posterior reversible encephalopathy syndrome (PRES) that developed after her DKA had resolved. Vasogenic oedema in PRES resolves if the underlying trigger is identified and eliminated. In this case, hypertension was identified as the likely precipitating factor and following treatment her vision and neurological symptoms rapidly improved. We suggest how recent DKA may have contributed to the development of PRES in this patient.

  20. Posterior reversible encephalopathy syndrome in alcoholic hepatitis: Hepatic encephalopathy a common theme.

    PubMed

    John, Elizabeth S; Sedhom, Ramy; Dalal, Ishita; Sharma, Ranita

    2017-01-14

    Posterior reversible encephalopathy syndrome (PRES) is a neuro-radiologic diagnosis that has become more widely recognized and reported over the past few decades. As such, there are a number of known risk factors that contribute to the development of this syndrome, including volatile blood pressures, renal failure, cytotoxic drugs, autoimmune disorders, pre-eclampsia, and eclampsia. This report documents the first reported case of PRES in a patient with severe alcoholic hepatitis with hepatic encephalopathy and delves into a molecular pathophysiology of the syndrome.

  1. An unusual presentation of a rare disease: posterior reversible encephalopathy syndrome following abdominal sepsis

    PubMed Central

    Richards, Carly R.N.; McMurray, Robert C.; Criman, Erik T.; Clark, Margaret E.; Gillern, Suzanne

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is an unusual disease of unknown incidence and cause. There are a wide range of associated, predisposing medical causes to include pregnancy, renal failure, immunosuppressive medication administration and hypertension. The diagnosis is made following the radiographic identification of characteristic vasogenic edema in the setting of neurologic impairment. A significant portion of patients will have long-term, if not permanent, sequelae of the disease. We present a patient who developed PRES following a hemicolectomy that was complicated by an anastomotic leak. She went on to a complete recovery following surgical treatment of the leak and supportive care. PMID:27887021

  2. Posterior reversible encephalopathy syndrome in alcoholic hepatitis: Hepatic encephalopathy a common theme

    PubMed Central

    John, Elizabeth S; Sedhom, Ramy; Dalal, Ishita; Sharma, Ranita

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neuro-radiologic diagnosis that has become more widely recognized and reported over the past few decades. As such, there are a number of known risk factors that contribute to the development of this syndrome, including volatile blood pressures, renal failure, cytotoxic drugs, autoimmune disorders, pre-eclampsia, and eclampsia. This report documents the first reported case of PRES in a patient with severe alcoholic hepatitis with hepatic encephalopathy and delves into a molecular pathophysiology of the syndrome. PMID:28127211

  3. [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.

  4. Gemcitabine and Cisplatin induced posterior reversible encephalopathy syndrome: A case report with review of literature

    PubMed Central

    Kabre, Rohit Santosh; Kamble, Krishna Marotirao

    2016-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a recently described, scarcely documented clinical entity. PRES is caused by various factors, the most common being hypertension, followed by nonhypertensive causes such as renal diseases and immunosuppressive therapy. Recently, some cases have been reported about the association of increased use of cytotoxic and immunosuppressive agents in cancer patients, and relevant reports have increased with advances in radiological examinations. Here, we report a case of gallbladder cancer with liver metastasis undergoing gemcitabine- and cisplatin-based chemotherapy who presented with complaints of seizures, headache, and bilateral lower limb weakness. Thorough clinical examination, biochemical analysis, and radiological evaluation led to diagnosis of PRES. It is important to recognize this syndrome which will facilitate early diagnosis and prompt symptomatic management. Removal of causative agent is an important aspect of management. Studies are needed to identify factors of adverse prognostic significance and to develop neuroprotective strategies. PMID:27843969

  5. 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

  6. Perioperative posterior reversible encephalopathy syndrome in 2 pediatric neurosurgery patients with brainstem ependymoma.

    PubMed

    Gephart, Melanie G Hayden; Taft, Bonnie P; Giese, Anne-Katrin; Guzman, Raphael; Edwards, Michael S B

    2011-03-01

    Posterior reversible encephalopathy syndrome (PRES) has been described in pediatric neurooncology patients, although it has not been documented perioperatively in pediatric neurosurgery patients not actively receiving chemotherapy. Recently at the authors' facility, 2 cases of PRES were diagnosed perioperatively in children with brainstem ependymoma. Both patients had presented with hypertension, altered mental status, and seizures and demonstrated MR imaging features consistent with PRES. The patients were treated with antiseizure and antihypertension medications, leading to improvement in both clinical symptoms and neuroimaging findings. These cases are the first to document PRES in perioperative pediatric neurosurgery patients not actively receiving chemotherapy. Both patients had ependymoma involving the brainstem, which may have led to intra- and perioperative hemodynamic instability (including hypertension) and predisposed them to this syndrome. An awareness of PRES in similar scenarios will aid in the prevention, diagnosis, and treatment of pediatric neurosurgery patients with this syndrome.

  7. Rare Case of Posterior Reversible Leukoencephalopathy Syndrome Secondary to Acute Chest Syndrome

    PubMed Central

    Klein, Daniel; El-Sherif, Yasir

    2016-01-01

    We present a case of 29/m with a history of sickle cell disease who presented to the emergency department with sudden onset of chest, trunk, extremity, and back pain, consistent in quality and severity with the patient's usual pain crises. Soon after admission to the medical unit for acute chest syndrome (ACS), the patient developed sudden onset of hypertension associated with left sided hemiplegia, lethargy, dysarthria, aphasia, and left sided facial droop. Neuroimaging revealed that on MRI Brain there was multifocal extensive signal abnormality and a small focal areas of hemorrhage compatible with posterior reversible leukoencephalopathy syndrome (PRES). Patient was treated with levetiracetam and phenytoin and improved soon afterwards, with resolution seen on follow-up MRI two months later. PMID:27957377

  8. Associative encoding in posterior piriform cortex during odor discrimination and reversal learning.

    PubMed

    Calu, Donna J; Roesch, Matthew R; Stalnaker, Thomas A; Schoenbaum, Geoffrey

    2007-06-01

    Recent proposals have conceptualized piriform cortex as an association cortex, capable of integrating incoming olfactory information with descending input from higher order associative regions such as orbitofrontal cortex and basolateral amygdala (ABL). If true, encoding in piriform cortex should reflect associative features prominent in these areas during associative learning involving olfactory cues. We recently reported that neurons in anterior piriform cortex (APC) in rats exhibited significant plasticity in their responses to odor cues during associative learning. Here, we have repeated this study, recording from neurons in posterior piriform cortex (PPC), a region of piriform cortex that receives much stronger input from ABL. If associative encoding in piriform cortex is driven by inputs from ABL, then we should see more plasticity in PPC neurons than we observed in APC. Consistent with this hypothesis, we found that PPC neurons were highly associative and appeared to be somewhat more likely than neurons recorded in APC to alter their responses to the odor cues after reversal of the odor-outcome associations in the task. Further, odor-selective PPC populations exhibited markedly different firing patterns based on the valence of the odor cue. These results suggest associative encoding in piriform cortex is represented in a topographical fashion, reflecting the stronger and more specific input from olfactory bulb concerning the sensory features of odors in anterior regions and stronger input from ABL concerning the meaning of odors in posterior regions.

  9. 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

  10. Status Epilepticus and Blindness in a Patient with Carfilzomib-Associated Posterior Reversible Encephalopathy Syndrome

    PubMed Central

    Ebrahem, Rawaa; Cooper, Scott; Manlove, Emily; Lee, Ricky

    2017-01-01

    Posterior reversible encephalopathy syndrome (PRES) is a neurological condition characterized by headaches, visual disturbances, and seizures. A magnetic resonance imaging (MRI) scan of an affected brain typically shows symmetrical white matter edema in the posterior cerebral hemispheres. The onset of PRES can constitute a medical emergency, especially when accompanied by status epilepticus. If promptly recognized and treated, the clinical syndrome and associated radiological findings are usually resolved in a matter of weeks or months. Carfilzomib is a proteasome inhibitor that is newly approved for relapsing myeloma in a patient who has received one or more lines of therapy. In this paper, we report on a 52-year-old female on carfilzomib for multiple myeloma who developed PRES following her second dose of treatment. She was admitted for chronic obstructive pulmonary disease (COPD) exacerbation, and while she was in the hospital, she developed a severe headache, blindness, and status epilepticus. A brain MRI showed signs consistent with PRES. After carfilzomib was discontinued, her symptoms resolved within three days. Unfortunately, the patient passed away shortly after being discharged, so there was no opportunity to perform a repeat MRI. PMID:28357173

  11. 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

  12. Various Imaging Manifestations of Posterior Reversible Encephalopathy Syndrome (PRES) on Magnetic Resonance Imaging (MRI)

    PubMed Central

    Raman, Rajesh; Devaramane, Radhika; Jagadish, Geetha Mukunda; Chowdaiah, Sanjana

    2017-01-01

    Summary Background Posterior reversible encephalopathy syndrome (PRES), also called the acute hypertensive encephalopathy and reversible posterior leukoencephalopathy syndrome (RPLS), is a neurotoxic syndrome of cerebral vasoregulation classically characterized by bilaterally symmetrical parieto-occipital edema. However, the imaging findings are variable and may occur in other locations such as the frontal lobes, thalami, basal ganglia and brainstem. Most commonly, PRES presents with hyperintense signals on T2 and FLAIR sequences. Restricted diffusion and hemorrhage are rare. This study presents the typical and atypical manifestations of PRES on 3T MR images. Material/Methods It is a retrospective study analyzing a radiology report database and MR images of 92 patients with a clinical and radiological diagnosis of PRES. The brain MRI images of these patients were evaluated. The regions involved and the signal intensity of the affected areas on T1, T2, FLAIR and DW sequences were recorded. The location of the abnormal signal intensity as well as the presence or absence of atypical features such as diffusion restriction and hemorrhage were also recorded. Results The most commonly affected region was the parieto-occipital lobes (100%), however, other atypical regions involved were the frontal lobes (30.4%), temporal lobes (8.69%), basal ganglia (22%), cerebellum(17.39%), brainstem(9%) and thalamus(4%). Some of the cases showed restricted diffusion (43%) and hemorrhage (9%). Conclusions The involvement of the parieto-occipital, frontal and temporal lobes is common in PRES. Occasionally, there may be an involvement of the basal ganglia, cerebellum and brainstem, with or without hemorrhage and restricted diffusion. Radiologists should be aware of the typical and atypical imaging manifestations of PRES in order to make an accurate diagnosis. PMID:28243339

  13. 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.

  14. Posterior Reversible Encephelopathy Syndrome Presenting as Quadriparesis in Pregnancy Induced Hypertension

    PubMed Central

    Pranita; Kumar, Ajit; Shahi, Seema

    2015-01-01

    Pregnancy Induced Hypertension (PIH) is a condition characterised by raised blood pressure in pregnancy. It affects approximately one out of every 14 pregnant women. Although PIH more commonly occurs during first pregnancy, it can also occur in subsequent pregnancies. It can present with variable complications related to vasospasm. But focal neurologic deficits are extremely rare in patients with PIH. We report a case of quadriparesis due to posterior reversible encephalopathy syndrome (PRES). A 36 year old full term pregnant female was admitted for emergency lower segment caesarean section (LSCS) as a result of uncontrolled PIH with early clinical signs of left ventricular failure. She was recovering well from pulmonary oedema after being provided with mechanical ventilation. However on 4th day she developed sudden onset quadriparesis without any alteration in sensorium, bladder & bowel disturbance or any sensory deficit. Diffusion weighted neuroimaging (DWI) was carried out which revealed finding suggestive of PRES. The patient was treated with antihypertensive which followed improvement in neurological deficit. Although rare, PRES should be considered as a potential cause of acute onset focal neurological deficit in pregnant females with PIH. With this case report we have tried to create awareness and vigilance about rare but potentially serious yet salvageable condition like PRES. PMID:26023585

  15. Muscle force and excursion requirements and moment arm analysis of a posterior-superior offset reverse total shoulder prosthesis.

    PubMed

    Onstot, Brian R; Jacofsky, Marc C; Hansen, Matthew L

    2013-01-01

    Current reverse total shoulder arthroplasty prosthesis designs do not permit offset of the humerus in the sagittal plane. Posteriorly shifting the humerus has the theoretical benefit of lengthening the infraspinatus and teres minor muscles and their external rotation moment arms, thereby improving the tension and efficiency of each external rotator and subsequently requiring each muscle to produce less force to rotate the arm. A cadaveric shoulder controller was used to quantify the impact of a novel posterior-superior offset reverse shoulder prosthesis on muscle length, moment arms, and muscle forces relative to a non-offset reverse shoulder design during two different motions: scapular plane abduction and internal/external rotation. The results of this study demonstrate that both the non-offset and offset reverse shoulder designs had similar force and excursion demands of the infraspinatus and teres minor muscles during both scapular abduction and internal and external rotation. Additionally, the offset reverse shoulder design was associated with significantly less over-tensioning of the middle and posterior deltoid and significantly more anatomic tensioning of the teres minor than the non-offset design. However, the offset reverse shoulder was observed to have more impingement than the non-offset design. These findings support the feasibility of this design: by restoring a more anatomic resting length to the deltoid and teres minor, the posterior-superior offset rTSA design may provide better teres minor function and rotational strength and may decrease the incidence of acromial stress fractures relative to the non-offset design. Clinical follow-up is required to confirm these findings.

  16. [Patient with posterior reversible encephalopathy syndrome with prolonged disturbance of consciousness and convulsion after cerebral aneurysm surgery].

    PubMed

    Ueda, Kayo; Hoshi, Takuo; Yorozu, Shinko; Okazaki, Junko; Motomura, Yuji; Masumoto, Tomohiko; Tsubokawa, Tsunehisa; Tanaka, Makoto

    2011-02-01

    A 73-year-old patient developed convulsion and prolonged disturbance of consciousness after clipping surgery for unruptured cerebral aneurysm. The patient's consciousness improved four days after surgery, and radiological findings suggested posterior reversible encephalopathy syndrome (PRES). The cause of PRES is thought to be dysfunction of blood brain barrier by a sudden increase in blood pressure. In case of unexplained convulsion and decreased level of consciousness, PRES should be considered with radiographic examinations including CT and MRI.

  17. Postpartum posterior reversible encephalopathy syndrome (PRES) in a twin pregnancy complicated by preeclampsia-eclampsia: case report.

    PubMed

    Papoutsis, D; El-Attabi, N; Sizer, A

    2014-01-01

    This is the second case in literature of posterior reversible encephalopathy syndrome (PRES) in a twin pregnancy complicated by preeclampsia-eclampsia. A 27-year-old primigravida with dichorionic diamniotic twin pregnancy was admitted at 36 weeks of gestation for induction of labour due to preeclampsia. On the second day postpartum, the patient developed severe hypertension, visual symptoms, confusion, headache, and eclamptic fits. Head computed tomography (CT) showed hypodense basal ganglia lesions. The patient was treated in the intensive treatment unit with hydralazine and labetalol infusions and anticonvulsants. Five days later, there was complete clinical improvement and follow-up magnetic resonance imaging (MRI) was normal. The patient was discharged 11 days post-delivery. Diagnosis of PRES is based on the presence of clinical features of acute neurologic compromise, abnormal neuroimaging findings, and complete reversibility of findings after prompt treatment. Early recognition and proper treatment result in complete reversibility of this condition.

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

    PubMed

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

    2016-03-01

    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.

  19. 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

  20. [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.

  1. The Number of Perforators Included in Reversed Flow Posterior Interosseous Artery Flap: Does It Affect the Incidence of Venous Congestion?

    PubMed Central

    Shaker, Ayman A.; Elbarbary, Amir S.; Sayed, Mohamed A.; Elghareeb, Mohamed A.

    2016-01-01

    Background: The purpose of this study is to decrease the incidence of venous congestion occurring in the reversed flow posterior interosseous artery flap used for coverage of hand defects. Methods: This may be achieved by studying the incidence of venous congestion in flaps including only 1 perforator and comparing the results with others including more than 1 perforator both in small and large sized flaps. Results: This study showed that inclusion of only 1 perforator in the flap decreased the incidence of venous congestion with complete flap loss in flaps to 5%. Also, it decreased the incidence of venous congestion with partial flap loss in flaps to 10%. Conclusions: The small sized reversed flow posterior interosseous artery flap should be less than 40 cm2 and should include only 1 perforator to decrease the incidence of venous congestion with partial and complete loss of the flap. The level of evidence for this study is the type II prospective comparative study. PMID:28293513

  2. Posterior Reversible Encephalopathy Syndrome (PRES): Restricted Diffusion does not Necessarily Mean Irreversibility

    PubMed Central

    Wagih, Alaa; Mohsen, Laila; Rayan, Moustafa M.; Hasan, Mo’men M.; Al-Sherif, Ashraf H.

    2015-01-01

    Summary Background Restricted diffusion is the second most common atypical presentation of PRES. This has a very important implication, as lesions with cytotoxic edema may progress to infarction. Several studies suggested the role of DWI in the prediction of development of infarctions in these cases. Other studies, however, suggested that PRES is reversible even with cytotoxic patterns. Our aim was to evaluate whether every restricted diffusion in PRES is reversible and what factors affect this reversibility. Material/Methods Thirty-six patients with acute neurological symptoms suggestive of PRES were included in our study. Inclusion criteria comprised imaging features of atypical PRES where DWI images and ADC maps show restricted diffusion. Patients were imaged with 0.2-T and 1.5-T machines. FLAIR images were evaluated for the severity of the disease and a FLAIR/DWI score was used. ADC values were selectively recorded from the areas of diffusion restriction. A follow-up MRI study was carried out in all patients after 2 weeks. Patients were classified according to reversibility into: Group 1 (reversible PRES; 32 patients) and Group 2 (irreversible changes; 4 patients). The study was approved by the University’s research ethics committee, which conforms to the declaration of Helsinki. Results The age and blood pressure did not vary significantly between both groups. The total number of regions involved and the FLAIR/DWI score did not vary significantly between both groups. Individual regions did not reveal any tendency for the development of irreversible lesions. Similarly, ADC values did not reveal any significant difference between both groups. Conclusions PRES is completely reversible in the majority of patients, even with restricted diffusion. None of the variables under study could predict the reversibility of PRES lesions. It seems that this process is individual-dependent. PMID:25960819

  3. Task-specific reversal of visual hemineglect following bilateral reversible deactivation of posterior parietal cortex: a comparison with deactivation of the superior colliculus.

    PubMed

    Lomber, S G; Payne, B R

    2001-01-01

    The purpose of the present study was to compare and contrast behavioral performance on three different tasks of spatial cognition during unilateral and bilateral reversible deactivation of posterior parietal cortex. Specifically, we examined posterior middle suprasylvian (pMS) sulcal cortex in adult cats during temporary and reversible cooling deactivation. In Task 1, the cats oriented to a high-contrast, black visual stimulus moved into the visual field periphery. In Task 2, the cats oriented to a static light-emitting diode (LED). Task 3 examined the cats' ability to determine whether a black-and-white checkered, landmark box was closer to the right or left side of the testing apparatus. Following training on all tasks, cryoloops were implanted bilaterally within the pMS sulcus. Unilateral deactivation of pMS sulcal cortex resulted in virtually no responses to either moved or static stimuli and virtually no responses to landmarks presented in the contralateral hemifield, and a profound contralateral hemifield neglect was induced. Responses to stimuli and landmarks presented in the ipsilateral hemifield were unimpaired. Additive, bilateral cooling of the homotopic region in the contralateral hemisphere, but not an adjacent region, resulted in reversal of the initial hemineglect for the moved stimulus, yet induced a complete failure to orient to peripheral static LED stimuli. Bilateral cooling also reversed the contralateral neglect of the landmark, but then cats could not accurately determine position of the landmark anywhere in the visual field because performance was reduced to chance levels for all landmark loci in both hemifields. In this instance, as the contralateral neglect disappeared during bilateral cooling of pMS cortex, a new spatial discrimination deficit was revealed across the entire visual field. We conclude that pMS cortex contributes in multiple ways to the analyses of space, and that these contributions cannot be safely predicted from analyses

  4. Posterior reversible encephalopathy syndrome as a complication of Henoch-Schönlein purpura in a seven-year-old girl.

    PubMed

    Dos Santos, Daiane; Langer, Felipe Welter; Dos Santos, Tatiane; Rafael Tronco Alves, Giordano; Feiten, Marisa; Teixeira de Paula Neto, Walter

    2017-02-01

    Introduction Henoch-Schönlein purpura is a multisystem small vessel vasculitis. Neurologic manifestations are uncommon. Posterior reversible encephalopathy syndrome is a rare complication of Henoch-Schönlein purpura with typical clinical and neuroimaging findings that occurs most commonly in the setting of severe hypertension and renal injury. Case presentation A seven-year-old girl was admitted to our institution presenting with clinical and laboratory findings suggestive of Henoch-Schönlein purpura. Glucocorticoid therapy was initiated, but five days following her admission, she developed altered consciousness, seizures, arterial hypertension, and cortical blindness. Brain MRI scan revealed areas of vasogenic oedema in parieto-occipital lobes, consistent with posterior reversible encephalopathy syndrome. She was immediately initiated on antihypertensives and antiepileptics, which successfully improved her neurologic symptoms. Further laboratory work-up disclosed a rapidly progressive glomerulonephritis secondary to Henoch-Schönlein purpura that was the likely cause of her sudden blood pressure elevation. Immunosuppressive therapy was undertaken, and at one-year follow-up, the patient exhibited complete renal and neurologic recovery. Conclusion Posterior reversible encephalopathy syndrome is a severe complication of Henoch-Schönlein purpura. If promptly diagnosed and treated, children with Henoch-Schönlein purpura presenting with posterior reversible encephalopathy syndrome usually have a good prognosis. Clinicians should be familiar with the characteristic presentation of posterior reversible encephalopathy syndrome and be aware that hypertension and renal injury may predispose Henoch-Schönlein purpura patients to developing this complication.

  5. Posterior leukoencephalopathy syndrome as a cause of reversible blindness during pregnancy.

    PubMed

    Onderoglu, Lutfu S; Dursun, Polat; Gultekin, Murat; Celik, Nilufer Y

    2007-08-01

    Cortical blindness is a rare and dramatic complication of pre-eclampsia. The precise nature of the pathogenesis of this condition has not previously been understood. Three preeclamptic patients with unremarkable previous medical history presented with acute blindness between the 28th and 33rd weeks of pregnancy. They were all diagnosed as posterior leukoencephalopathy syndrome (PLES). In all these patients, MRI study revealed the typical feature of gray-white matter edema localized to the temporo-parieto-occipital areas. Vision and MRI findings were restored in all patients after delivery. Although PLES has been described as a puerperal clinicoradiologic entity, it may be seen in preeclamptic-eclamptic patients during the pregnancy. Therefore neuro-imaging studies should be carried out in pregnant patients with visual disturbances in order to exclude PLES. Prompt diagnosis, immediate control of blood pressure, and elimination of possible causes resolves clinical and imaging findings.

  6. [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.

  7. TESTING BASAL GANGLIA MOTOR FUNCTIONS THROUGH REVERSIBLE INACTIVATIONS IN THE POSTERIOR INTERNAL GLOBUS PALLIDUS

    PubMed Central

    Desmurget, M.; Turner, R.S.

    2010-01-01

    To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually-directed reaching. Injections were made in 2 monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly-selected target locations. Following sGPi inactivations: (1) Peak velocity and acceleration were decreased in nearly all sessions whereas movement duration lengthened inconsistently. (2) Reaction times were unaffected on average, although minor changes were observed in several individual sessions. (3) Outward reaches showed a substantial hypometria that correlated closely with bradykinesia, but directional accuracy was unaffected. (4) End-point accuracy was preserved for the slow visually-guided return movements. (5) No impairments were found in the rapid chaining of out-and-back movements, in the selection or initiation of four independent reaches in quick succession, or in the quick on-line correction of initially mis-directed reaches. (6) Inactivation-induced reductions in the magnitude of movement-related muscle activity (EMG) correlated with the severity of slowing and hypometria. There was no evidence for inactivation-induced alterations in the relative timing of EMG bursts, excessive co-contraction, or impaired suppression of antagonist EMG. Therefore, disconnecting the BG motor pathway consistently produced bradykinesia and hypometria, but seldom affected movement initiation time, feedback-mediated guidance, the capacity to produce iterative reaches, or the ability to abruptly reverse movement direction. These results are discussed with reference to the idea that the BG motor loop may regulate energetic expenditures during movement (i.e., movement “vigor”). PMID:18077663

  8. Learning and recall of form discriminations during reversible cooling deactivation of ventral-posterior suprasylvian cortex in the cat.

    PubMed

    Lomber, S G; Payne, B R; Cornwell, P

    1996-02-20

    Extrastriate visual cortex of the ventral-posterior suprasylvian gyrus (vPS cortex) of freely behaving cats was reversibly deactivated with cooling to determine its role in performance on a battery of simple or masked two-dimensional pattern discriminations, and three-dimensional object discriminations. Deactivation of vPS cortex by cooling profoundly impaired the ability of the cats to recall the difference between all previously learned pattern and object discriminations. However, the cats' ability to learn or relearn pattern and object discriminations while vPS was deactivated depended upon the nature of the pattern or object and the cats' prior level of exposure to them. During cooling of vPS cortex, the cats could neither learn the novel object discriminations nor relearn a highly familiar masked or partially occluded pattern discrimination, although they could relearn both the highly familiar object and simple pattern discriminations. These cooling-induced deficits resemble those induced by cooling of the topologically equivalent inferotemporal cortex of monkeys and provides evidence that the equivalent regions contribute to visual processing in similar ways.

  9. A case of posterior reversible encephalopathy syndrome associated with gilenya(®) (fingolimod) treatment for multiple sclerosis.

    PubMed

    Lindå, Hans; von Heijne, Anders

    2015-01-01

    We describe posterior reversible encephalopathy syndrome (PRES) in a woman with multiple sclerosis treated with Gilenya(®) (Fingolimod). The first symptoms appeared after 21 months of fingolimod treatment. She experienced headache, altered mental status, cognitive deficits, seizures, and visual disturbances. Not at any time during the course of the disease could any signs of infection or rheumatic disorder be detected. Test for anti-neuronal antibodies was also negative. Her blood pressure was normal. MRI showed widespread cortical and subcortical changes with some mass-effect in the temporo-occipital-parietal lobes in the left hemisphere. Contrast enhancement was seen in the leptomeninges and, in addition, there were no areas with restricted diffusion and no signs of hemorrhage. Her condition deteriorated until fingolimod was discontinued. Slowly her condition improved and after 8 months, the only symptoms that remained were two small, non-corresponding, right inferior scotomas. We believe that all symptoms, the clinical course, and the MRI findings in this case can all be explained by considering PRES, a probably rare, but serious, side effect of fingolimod treatment.

  10. Delayed onset of posterior reversible encephalopathy syndrome in a case of scleroderma renal crisis with maintenance hemodialysis

    PubMed Central

    Chen, Ching-Yang; Hung, Shin-Yuan; Lee, Yi-Jer; Lin, Yi-Chan; Pai, Chu-Cheng

    2016-01-01

    Abstract Introduction: In some cases, scleroderma renal crisis (SRC) is not easily distinguishable from other thrombotic microangiopathies such as thrombotic thrombocytopenic purpura, especially when the presentation includes neurological or extra-renal manifestations. Here, we present a case of SRC who developed a rare neurotoxic complication, posterior reversible encephalopathy syndrome (PRES). A 36-year-old man with a history of diffuse cutaneous systemic sclerosis developed SRC and acute-on-chronic renal failure and ultimately required maintenance hemodialysis. Three weeks after starting hemodialysis, the patient presented with confusion and a new-onset seizure disorder. Laboratory examinations revealed thrombocytopenia, a low haptoglobin level, and schizocytes on a blood smear. SRC-related PRES was considered first after PRES was confirmed by brain magnetic resonance imaging. Antihypertensive therapy comprising captopril and amlodipine was administered, and the patient experienced a complete neurological recovery 3 days later without plasma exchange. In all previously reported cases of SRC-associated PRES, PRES developed before hemodialysis. Our report is, therefore, the first to describe a case of onset of SRC-related PRES 3 weeks after the initiation of maintenance hemodialysis. Conclusion: This case demonstrates that microangiopathy and extra-renal manifestations can develop even in SRC patients with end-stage renal disease and that these manifestations can be successfully managed with angiotensin-converting enzyme inhibitors (ACEIs) and aggressive blood pressure control. We recommend continuing ACEI therapy if elevated blood pressure persists after maintenance hemodialysis. PMID:28033278

  11. 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

  12. A Grave Outcome of Posterior Reversible Encephalopathy Syndrome in a Patient Receiving Avastin (Bevacizumab) for Metastatic High-Grade Serous Ovarian Cancer

    PubMed Central

    Elmalik, Hind H.; ElAzzazy, Shereen; Salem, Khaled S.; Bujassoum, Salha

    2015-01-01

    A 45-year-old female developed neurological symptoms and elevated diastolic blood pressure while on bevacizumab (Avastin) and gemcitabine for recurrent carboplatin-resistant high-grade serous ovarian cancer. A brain MRI diagnosed our patient with posterior reversible encephalopathy syndrome. We are discussing her presenting symptoms in this paper as well as the management and the outcome. We emphasize the importance of keeping this rare but very serious complication in all patients receiving bevacizumab. PMID:26351436

  13. 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…

  14. Cortical blindness after contrast-enhanced CT scan in a patient of sarcoidosis - Is it related to posterior reversible encephalopathy syndrome?

    PubMed

    Suri, Vinit; Agarwal, Ritu; Jadhao, Nilesh; Ahuja, Gulshan K

    2011-10-01

    Transient cortical blindness (TCB) is a well known but rare complication of administration of contrast agent. In this case report, we present a 53-year-old woman who is a follow-up case of sarcoidosis and developed TCB with focal neurological symptoms following contrast-enhanced computed tomography scan. Magnetic resonance imaging revealed bilateral T2/Flair hyperintensities in parieto-occipital, high frontal, and cerebellar hemispheres with involvement of corpus callosum. Clinically and radiologically patient improved significantly in 4 days. The exact mechanism is still speculative and its possible relationship with posterior reversible encephalopathy syndrome is briefly discussed. The patient's symptoms were presumed to be exacerbated by presence of hypertension, underlying autoimmune disorder, sepsis, and high osmolality of contrast agent. Though there is no definite evidence to suggest that a certain treatment regimen improves the natural history of this disease but control of risk factors can possibly prevent this rare but devastating complication.

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

    PubMed

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

    2016-04-01

    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.

  16. 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

  17. 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…

  18. 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

  19. Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC) affects differently working and long-term memory on two foraging tasks.

    PubMed

    Espina-Marchant, Pablo; Pinto-Hamuy, Teresa; Bustamante, Diego; Morales, Paola; Robles, Luis; Herrera-Marschitz, Mario

    2006-01-01

    Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC) was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable.

  20. Percutaneous Posterior Calcaneal Osteotomy.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Different types of posterior calcaneal osteotomy are used for calcaneal realignment in the management of hindfoot deformity. We describe a percutaneous technique of posterior calcaneal osteotomy that can be either a Dwyer-type closing wedge osteotomy or displacement osteotomy.

  1. Posterior Cruciate Ligament Injury

    MedlinePlus

    ... ACL connect your thighbone (femur) to your shinbone (tibia). If either ligament is torn, it might cause ... ligaments connect the thighbone (femur) to the shinbone (tibia). The anterior and posterior cruciate ligaments form an " ...

  2. Posterior ankle impingement syndrome.

    PubMed

    Maquirriain, Javier

    2005-10-01

    Posterior ankle impingement syndrome is a clinical disorder characterized by posterior ankle pain that occurs in forced plantar flexion. The pain may be acute as a result of trauma or chronic from repetitive stress. Pathology of the os trigonum-talar process is the most common cause of this syndrome, but it also may result from flexor hallucis longus tenosynovitis, ankle osteochondritis, subtalar joint disease, and fracture. Patients usually report chronic or recurrent posterior ankle pain caused or exacerbated by forced plantar flexion or push-off maneuvers, such as may occur during dancing, kicking, or downhill running. Diagnosis of posterior ankle impingement syndrome is based primarily on clinical history and physical examination. Radiography, scintigraphy, computed tomography, and magnetic resonance imaging depict associated bone and soft-tissue abnormalities. Symptoms typically improve with nonsurgical management, but surgery may be required in refractory cases.

  3. 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.

  4. Posterior Fossa Tumors.

    PubMed

    Brandão, Lara A; Young Poussaint, Tina

    2017-02-01

    Pediatric brain tumors are the leading cause of death from solid tumors in childhood. The most common posterior fossa tumors in children are medulloblastoma, atypical teratoid/rhabdoid tumor, cerebellar pilocytic astrocytoma, ependymoma, and brainstem glioma. Location, and imaging findings on computed tomography (CT) and conventional MR (cMR) imaging may provide important clues to the most likely diagnosis. Moreover, information obtained from advanced MR imaging techniques increase diagnostic confidence and help distinguish between different histologic tumor types. Here we discuss the most common posterior fossa tumors in children, including typical imaging findings on CT, cMR imaging, and advanced MR imaging studies.

  5. Posterior crossbites in children.

    PubMed

    Zhu, J F; Crevoisier, R; King, D L; Henry, R; Mills, C M

    1996-11-01

    Posterior crossbite, the most common malocclusion in young children, can be caused by a variety of skeletal, muscular, or dental factors. This condition produces insufficient maxillary arch width and is frequently associated with various oral sucking and postural habits. If left untreated, this problem can result in adverse skeletal growth changes. Various mechanical treatment modalities designed to expand the posterior maxillary arch width are available to correct this problem. The appropriate treatment method depends on the patient's age and level of cooperation as well as the determined etiology of the constriction.

  6. 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.

  7. 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

  8. Posterior Circulation Ischemic Stroke.

    PubMed

    Go, Steven

    2015-01-01

    Approximately 20-25% of all acute strokes occur in the posterior circulation. These strokes can be rather difficult to diagnose because they present in such diverse ways, and can easily be mistaken for more benign entities. A fastidious history, physical exam, high clinical suspicion, and appropriate use of imaging are essential for the emergency physician to properly diagnose and treat these patients. Expert stroke neurologist consultation should be utilized liberally.

  9. Posterior interosseous neuropathy

    PubMed Central

    Kele, Henrich; Xia, Annie; Weiler, Markus; Schwarz, Daniel; Bendszus, Martin; Pham, Mirko

    2016-01-01

    Objective: To investigate the spatial pattern of lesion dispersion in posterior interosseous neuropathy syndrome (PINS) by high-resolution magnetic resonance neurography. Methods: This prospective study was approved by the local ethics committee and written informed consent was obtained from all patients. In 19 patients with PINS and 20 healthy controls, a standardized magnetic resonance neurography protocol at 3-tesla was performed with coverage of the upper arm and elbow (T2-weighted fat-saturated: echo time/repetition time 52/7,020 milliseconds, in-plane resolution 0.27 × 0.27 mm2). Lesion classification of the radial nerve trunk and its deep branch (which becomes the posterior interosseous nerve) was performed by visual rating and additional quantitative analysis of normalized T2 signal of radial nerve voxels. Results: Of 19 patients with PINS, only 3 (16%) had a focal neuropathy at the entry of the radial nerve deep branch into the supinator muscle at elbow/forearm level. The other 16 (84%) had proximal radial nerve lesions at the upper arm level with a predominant lesion focus 8.3 ± 4.6 cm proximal to the humeroradial joint. Most of these lesions (75%) followed a specific somatotopic pattern, involving only those fascicles that would form the posterior interosseous nerve more distally. Conclusions: PINS is not necessarily caused by focal compression at the supinator muscle but is instead frequently a consequence of partial fascicular lesions of the radial nerve trunk at the upper arm level. Neuroimaging should be considered as a complementary diagnostic method in PINS. PMID:27683851

  10. 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

  11. Symptomatic posterior mediastinal angioleiomyoma.

    PubMed

    I, Hoseok; Jeong, Yeon Joo; Choi, Kyung Un; Kim, Yeong-Dae

    2008-08-30

    We report a case of a symptomatic angioleiomyoma in the left posterior mediastinum. A 66-year-old woman presented with left back and flank pain for 6 months. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-circumscribed 4.3 cm round mass. The mass was initially diagnosed as nerve sheath tumor, because of her symptoms and its close location to the sympathetic trunk and intercostal nerve. It was uneventfully removed through video-assisted thoracoscopic surgery. The pathology revealed an angioleiomyoma.

  12. 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

  13. Posterior Fossa Meningioma

    PubMed Central

    Saleh, Essam A.; Taibah, Abdel Kader; Achilli, Vittorio; Aristegui, Miguel; Mazzoni, Antonio; Sanna, Mario

    1994-01-01

    Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far. ImagesFigure 1Figure 2Figure 3Figure 4p206-bFigure 5p207-bFigure 5 PMID:17171173

  14. Negative participation of the left posterior fascicle in the reentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia.

    PubMed

    Morishima, Itsuro; Nogami, Akihiko; Tsuboi, Hideyuki; Sone, Takahito

    2012-05-01

    Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the sinus beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.

  15. 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.

  16. Posterior pole tumor update.

    PubMed

    Ou, Judy I; Wheeler, Sharon M; O'Brien, Joan M

    2002-12-01

    This chapter focuses on the diagnosis and management of choroidal melanoma in light of recent findings from the COMS. Retinoblastoma is emphasized to describe recent trends in primary treatment away from EBRT and toward chemoreduction with local therapy. In addition, vascular and glial tumors of the retina and tumors of the retinal pigment epithelium are described because of the association between these lesions and systemic disease. Recent advances in treatment and genetic testing for these diseases are discussed. Finally, ocular metastasis, intraocular lymphoid tumors, and intraocular leukemia are included because of their importance in determining systemic treatment and prognosis. The chapter gives an overview of important posterior pole tumors and highlights recent developments in the management of each intraocular disease process.

  17. Posterior Probability and Fluctuation Theorem in Stochastic Processes

    NASA Astrophysics Data System (ADS)

    Ohkubo, Jun

    2009-12-01

    A generalization of fluctuation theorems in stochastic processes is proposed. The new theorem is written in terms of posterior probabilities, which are introduced via Bayes’ theorem. In conventional fluctuation theorems, a forward path and its time reversal play an important role, so that a microscopically reversible condition is essential. In contrast, the microscopically reversible condition is not necessary in the new theorem. It is shown that the new theorem recovers various theorems and relations previously known, such as the Gallavotti-Cohen-type fluctuation theorem, the Jarzynski equality, and the Hatano-Sasa relation, when suitable assumptions are employed.

  18. 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

  19. Posterior sampling with improved efficiency

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.

    1998-12-01

    The Markov Chain Monte Carlo (MCMC) technique provides a means to generate a random sequence of model realizations that sample the posterior probability distribution of a Bayesian analysis. That sequence may be used to make inferences about the model uncertainties that derive from measurement uncertainties. This paper presents an approach to improving the efficiency of the Metropolis approach to MCMC by incorporating an approximation to the covariance matrix of the posterior distribution. The covariance matrix is approximated using the update formula from the BFGS quasi-Newton optimization algorithm. Examples are given for uncorrelated and correlated multidimensional Gaussian posterior distributions.

  20. 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.

  1. 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.

  2. 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.

  3. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    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,…

  4. 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

  5. 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)

  6. 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

  7. 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

  8. Distortions of posterior visual space.

    PubMed

    Phillips, Flip; Voshell, Martin G

    2009-01-01

    The study of spatial vision is a long and well traveled road (which, of course, converges to a vanishing point at the horizon). Its various distortions have been widely investigated empirically, and most concentrate, pragmatically, on the space anterior to the observer. The visual world behind the observer has received relatively less attention and it is this perspective the current experiments address. Our results show systematic perceptual distortions in the posterior visual world when viewed statically. Under static viewing conditions, observer's perceptual representation was consistently 'spread' in a hyperbolic fashion. Directions to distant, peripheral locations were consistently overestimated by about 11 degrees from the ground truth and this variability increased as the target was moved toward the center of the observer's back. The perceptual representation of posterior visual space is, no doubt, secondary to the more immediate needs of the anterior visual world. Still, it is important in some domains including certain sports, such as rowing, and in vehicular navigation.

  9. 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

  10. Reversible Computing

    DTIC Science & Technology

    1980-02-01

    will have been introduced. 9. Reversible celular autemata We shall assume the reader to have some familiarity with the concept of cel- lular...10003 Mr. Kin B. Thcmpson 1 copy Technical Director Information Systems Divisia.i Naval Research Laboratory (OP-91T) Technical Information Division

  11. REVERSE OSMOSIS,

    DTIC Science & Technology

    acetate membranes. Mechanisms of the process and porous cellulose acetate membrane technology are briefly reviewed. Based on a general capillary...The reverse osmosis process is discussed with particular reference to systems involving aqueous solutions and Loeb-Sourirajan-type porous cellulose

  12. Posterior commissure of the human larynx revisited.

    PubMed

    Tucker, John A; Tucker, Sean T

    2010-05-01

    The existence of the posterior commissure (PC) of the human larynx has been disputed (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). "The term posterior commissure has no relevance to anatomical structure. The term commissure means a joining together. The bilateral vocal folds never join at their posterior ends. The posterior aspect of the glottis is a wall. The posterior lateral aspect of the posterior glottis is also the lateral wall of the posterior glottis" (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). This study is intended to clarify the development of anatomical and morphological aspects of the PC in conjunction with a clinical classification of the larynx in sagittal view. This study uses human embryo and fetal laryngeal sections from the Carnegie Collection of Human Embryos (the world standard) and whole organ laryngeal sections from the Tucker Laryngeal Fetal Collection. Correlation of histologic and gross anatomical structure is made with the Hirano et al atlas, the Vidić Photographic Atlas of the Human Body, and the O'Rahilly Embryonic Atlas. Embryologic data clearly describe and illustrate the posterior union of the cricoid cartilage with formation of the PC. The anatomical functional aspects of the posterior lateral cricoid lamina as the supporting buttress of the articulating arytenoid cartilages are illustrated.

  13. Isolated posterior cruciate ligament calcification

    PubMed Central

    Koukoulias, Nikolaos E; Papastergiou, Stergios G

    2011-01-01

    The authors present a case of calcified posterior cruciate ligament (PCL). A 61-year-old female presented in our department reporting 12 months history of knee pain that was getting worse during the night. The patient was under medication for epileptic seizure, osteoporosis and hyperthyroidism. X-rays demonstrated calcification of the PCL. CT and MRI excluded any other intra-articular and extra-articular pathology. Arthroscopic debridement of the calcium deposits was performed and the symptoms resolved immediately, while the postoperative x-rays were normal. Histological examination confirmed the calcium nature of the lesion. Two years postoperatively the patient remains asymptomatic. PMID:22669889

  14. 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

  15. 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

  16. 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.

  17. Imaging of the Posterior Skull Base.

    PubMed

    Job, Joici; Branstetter, Barton F

    2017-01-01

    The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures.

  18. Posterior peritoneal recesses: assessment using CT

    SciTech Connect

    Rubenstein, W.A.; Auh, Y.H.; Zirinsky, K.; Kneeland, J.B.; Whalen, J.P.; Kazam, E.

    1985-08-01

    Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces and particularly their appearance on computed tomographic scans, are illustrated in this paper.

  19. Posterior ankle impingement in the dancer.

    PubMed

    Moser, Brad R

    2011-01-01

    Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiographic studies needed to further evaluate a dancer with suspected posterior ankle impingement.

  20. Treatment of Locked Posterior Shoulder Dislocation With Bone Defect.

    PubMed

    Khira, Yousuf M; Salama, Adel M

    2017-03-14

    Locked posterior shoulder dislocation is an uncommon condition and is associated with a reverse Hill-Sachs lesion in 50% of cases. The condition is likely to occur in cases of violent trauma, seizures, or electric shock. Unrecognized dislocation with humeral head fracture affects joint function and humeral head vascularity and may lead to chronic instability, osteonecrosis, and osteoarthritis. A group of 12 patients, including 10 men and 2 women, with neglected locked posterior shoulder dislocation with a reverse Hill-Sachs lesion were treated with the modified McLaughlin technique. The added bone graft from the iliac crest was impacted in the defect and fixed with screws. Mean follow-up was 30 months (range, 24-48 months). The range of forward flexion was 150˚ to 175˚ (average, 165˚), external rotation ranged from 60˚ to 80˚ (average, 75˚), internal rotation ranged from 40˚ to 60˚ (average, 50˚), and average abduction was 150˚ (range, 145˚-160˚). The modified University of California Los Angeles (UCLA) scoring system was used for postoperative clinical evaluation. Total UCLA scores immediately postoperatively ranged from 22 to 28 points (average, 26.5 points) and averaged 30 points (range, 28-33 points) at last follow-up. No recurrence of dislocation occurred during the follow-up period. Of the study patients, 10 returned to their previous job and 2 modified their manual work. The modified McLaughlin technique with added iliac crest bone graft to fill the defect and prevent humeral head deformity is a successful technique for the treatment of patients with chronic locked posterior shoulder dislocation. [Orthopedics. 201x; xx(x):xx-xx.].

  1. Posterior repair and sexual function

    PubMed Central

    Komesu, Yuko M.; Rogers, Rebecca G.; Kammerer-Doak, Dorothy N.; Barber, Matthew D.; Olsen, Ambre L.

    2011-01-01

    OBJECTIVE The purpose of this study was to determine the effect of posterior repair (PR) on sexual function in patients who have undergone incontinence and/or pelvic reconstructive surgery. STUDY DESIGN A cohort study of women who underwent incontinence and/or prolapse surgery was performed. Participants completed the pelvic organ prolapse urinary incontinence sexual questionnaire (PISQ) before and after the operation. PISQ scores were compared between women who underwent PR and women who did not. RESULTS Of 73 study participants, 30 women underwent PR; 43 women did not (no PR). Although there was no difference in dyspareunia between groups pre-op, dyspareunia prevalence post-op was significantly lower in the no PR group. Preoperative PISQ scores were similar between groups. After the operation, both groups significantly improved their PISQ scores, without a difference between groups. CONCLUSION Although the incidence of dyspareunia differed between PR and no PR groups, overall improvement in sexual function was reflected in improved total PISQ scores that occurred irrespective of PR performance. PMID:17618777

  2. Simultaneous bilateral posterior dislocation of the shoulder: diagnostic problems and management. A case report.

    PubMed

    Iosifidis, Michael I; Giannoulis, Ioannis; Traios, Stavros; Giantsis, Georgios

    2006-08-01

    We present the case of a patient who sustained simultaneous bilateral posterior dislocation of the shoulder after a possible epileptic fit. The confirmation of the diagnosis was reached only by a computed tomography (CT) scan, after the clinical suspicion. Under general anesthesia, close reduction of both shoulder dislocations was done. Posterior dislocation of the shoulder-especially the bilateral one-is very rare. When the history describes an electric shock or convulsive seizure, any shoulder injury demands a careful clinical and radiological evaluation. It is usually associated with reverse Hill-Sachs lesion (an impression defect of the anteromedial aspect of the humeral head), in which the size determines the treatment options.

  3. Treatment implications of posterior fossa ependymoma subgroups.

    PubMed

    Ramaswamy, Vijay; Taylor, Michael D

    2016-11-15

    Posterior fossa ependymoma comprises two distinct molecular entities, ependymoma_posterior fossa A (EPN_PFA) and ependymoma_posterior fossa B (EPN_PFB), with differentiable gene expression profiles. As yet, the response of the two entities to treatment is unclear. To determine the relationship between the two molecular subgroups of posterior fossa ependymoma and treatment, we studied a cohort of 820 patients with molecularly profiled, clinically annotated posterior fossa ependymomas. We found that the strongest predictor of poor outcome in patients with posterior fossa ependymoma across the entire age spectrum was molecular subgroup EPN_PFA, which was recently reported in the paper entitled "Therapeutic impact of cytoreductive surgery and irradiation of posterior fossa ependymoma in the molecular era: a retrospective multicohort analysis" in the Journal of Clinical Oncology. Patients with incompletely resected EPN_PFA tumors had a very poor outcome despite receiving adjuvant radiation therapy, whereas a substantial proportion of patients with EPN_PFB tumors can be cured with surgery alone.

  4. Congenital basis of posterior fossa anomalies

    PubMed Central

    Cotes, Claudia; Bonfante, Eliana; Lazor, Jillian; Jadhav, Siddharth; Caldas, Maria; Swischuk, Leonard

    2015-01-01

    The classification of posterior fossa congenital anomalies has been a controversial topic. Advances in genetics and imaging have allowed a better understanding of the embryologic development of these abnormalities. A new classification schema correlates the embryologic, morphologic, and genetic bases of these anomalies in order to better distinguish and describe them. Although they provide a better understanding of the clinical aspects and genetics of these disorders, it is crucial for the radiologist to be able to diagnose the congenital posterior fossa anomalies based on their morphology, since neuroimaging is usually the initial step when these disorders are suspected. We divide the most common posterior fossa congenital anomalies into two groups: 1) hindbrain malformations, including diseases with cerebellar or vermian agenesis, aplasia or hypoplasia and cystic posterior fossa anomalies; and 2) cranial vault malformations. In addition, we will review the embryologic development of the posterior fossa and, from the perspective of embryonic development, will describe the imaging appearance of congenital posterior fossa anomalies. Knowledge of the developmental bases of these malformations facilitates detection of the morphological changes identified on imaging, allowing accurate differentiation and diagnosis of congenital posterior fossa anomalies. PMID:26246090

  5. Recurrent posterior shoulder instability. Diagnosis and treatment.

    PubMed

    Pollock, R G; Bigliani, L U

    1993-06-01

    Recurrent posterior glenohumeral instability is regarded as a difficult problem to diagnose and treat. A careful history and physical examination are the most helpful tools in making this diagnosis. A positive posterior stress test, demonstrable posterior subluxation, and a sulcus sign are frequently present on examination. Special roentgenographic studies, such as the computerized arthrotomography (arthro-CT) scan, may be used in cases in which plain roentgenographs suggest bony glenoid abnormalities. When conservative therapy fails, there is no consensus on the operative treatment. Procedures that address the soft tissues, such as capsulorrhaphy and posterior labral repair, as well as those that alter the bony geometry of the joint, such as posterior bone blocks and glenoid or humeral osteotomies, have been described. Capsular laxity is the most common pathologic finding in the authors' experience, and they favor the use of a posterior-inferior capsular shift procedure to correct this problem. Augmentation of the repair with a posterior bone block is reserved for unusual cases, such as when glenoid hypoplasia is present or in certain revision situations.

  6. 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.

  7. 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

  8. Posterior cruciate ligament (PCL) injury - aftercare

    MedlinePlus

    Adib F, Curtis C, Bienkowski P Micheli LJ. Posterior cruciate ligament sprain. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, ...

  9. Gibbs Sampling for Marginal Posterior Expectations

    DTIC Science & Technology

    1991-11-19

    Achcar and Smith (1989) shows that performance of the Laplace method is often very sensitive to parametrization. Morris (1988) offers expansions based on...Berkeley Symp. 1, 453-468. Lindley, D.V. (1980). "Approximate Bayesian Methods" in Bayesian Statistics, J.M. Bernardo, M.H. DeGroot , D.V. Lindley...A.F.M. Smith, University Press, Valencia, Spain. Morris , C. "Approximating Posterior Distributions and Posterior Moments" In: Bayesian Statistics 3, J.M

  10. [Posterior cortical atrophy (Benson-syndrome)].

    PubMed

    Rózsa, Anikó; Szilvássy, Ildikó; Kovács, Krisztina; Boór, Krisztina; Gács, Gyula

    2010-01-30

    We present the characteristics of posterior cortical atrophy--a very rare cortical dementia--in a 69 year old woman's case. Our patient's symptoms began with a visual problem which was initially explained by ophthalmological disorder. After neurological exam visual agnosia was diagnosed apart from other cognitive disorder (alexia without agraphia, acalculia, prosopagnosia, constructional disorder, clock-time recognition disorder, dressing apraxia, visuospatial disorientation). The brain MRI showed bilateral asymmetric parieto-occipital atrophy which is characteristic of posterior cortical atrophy.

  11. 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.

  12. 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.

  13. 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.

  14. Spatio-Temporal Updating in the Left Posterior Parietal Cortex

    PubMed Central

    Wada, Makoto; Takano, Kouji; Ikegami, Shiro; Ora, Hiroki; Spence, Charles; Kansaku, Kenji

    2012-01-01

    Adopting an unusual posture can sometimes give rise to paradoxical experiences. For example, the subjective ordering of successive unseen tactile stimuli delivered to the two arms can be affected when people cross them. A growing body of evidence now highlights the role played by the parietal cortex in spatio-temporal information processing when sensory stimuli are delivered to the body or when actions are executed; however, little is known about the neural basis of such paradoxical feelings resulting from such unusual limb positions. Here, we demonstrate increased fMRI activation in the left posterior parietal cortex when human participants adopted a crossed hands posture with their eyes closed. Furthermore, by assessing tactile temporal order judgments (TOJs) in the same individuals, we observed a positive association between activity in this area and the degree of reversal in TOJs resulting from crossing arms. The strongest positive association was observed in the left intraparietal sulcus. This result implies that the left posterior parietal cortex may be critically involved in monitoring limb position and in spatio-temporal binding when serial events are delivered to the limbs. PMID:22768126

  15. 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.

  16. Posterior cruciate ligament removal contributes to abnormal knee motion during posterior stabilized total knee arthroplasty.

    PubMed

    Cromie, Melinda J; Siston, Robert A; Giori, Nicholas J; Delp, Scott L

    2008-11-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20-60 degrees ) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1 +/- 4.3 mm to 10.4 +/- 5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2 +/- 9.6 degrees to 49.3 +/- 7.3 degrees). Implanting the prosthesis increased the amount of anterior translation (to 16.1 +/- 4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0-60 degrees) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis.

  17. Fundus autofluorescence imaging in posterior uveitis.

    PubMed

    Durrani, Khayyam; Foster, C Stephen

    2012-01-01

    Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.

  18. Posterior cortical atrophy: a brief review.

    PubMed

    Kirshner, Howard S; Lavin, Patrick J M

    2006-11-01

    Posterior cortical atrophy is a striking clinical syndrome in which a dementing illness begins with visual symptoms. Initially, the problem may seem to be loss of elementary vision, but over time the patient develops features of visual agnosia, topographical difficulty, optic ataxia, simultanagnosia, ocular apraxia (Balint's syndrome), alexia, acalculia, right-left confusion, and agraphia (Gerstmann's syndrome), and later a more generalized dementia. Occasional patients have visual hallucinations and signs of Parkinson's disease or Lewy body dementia. A number of different neuropathologic disorders are associated with posterior cortical atrophy.

  19. 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.

  20. Treatment rationale of fractured posterior teeth.

    PubMed

    Silvestri, A R; Singh, I

    1978-11-01

    The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

  1. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  2. 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)

  3. Complicated posterior capsulorhexis: aetiology, management, and outcome

    PubMed Central

    Van Cauwenberge, F.; Rakic, J.; Galand, A.

    1997-01-01

    BACKGROUND—A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome.
METHODS—Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue.
RESULTS—There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p=0.002 and p=0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of ≥ 20/40 was obtained in 93% of the patients.
CONCLUSION—Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

 PMID:9135382

  4. Fuchs's heterochromic cyclitis and posterior capsulotomy.

    PubMed Central

    Roussel, T J; Coster, D J

    1985-01-01

    We report a case of intractable glaucoma following an uncomplicated secondary posterior capsulotomy in a 48-year-old male with Fuchs's heterochromic cyclitis. The patient had been free of inflammation and glaucoma since cataract extraction 27 years previously. We also report the results of phenotypic analysis of lymphocytes removed from the anterior chamber. Images PMID:3859323

  5. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  6. BAER suppression during posterior fossa dural opening

    PubMed Central

    Shields, Christopher B.; Shields, Lisa B. E.; Jiang, Yi Dan; Yao, Tom; Zhang, Yi Ping; Sun, David A.

    2015-01-01

    Background: Intraoperative monitoring with brainstem auditory evoked responses (BAER) provides an early warning signal of potential neurological injury and may avert tissue damage to the auditory pathway or brainstem. Unexplained loss of the BAER signal in the operating room may present a dilemma to the neurosurgeon. Methods: This paper documents two patients who displayed a unique mechanism of suppression of the BAER apparent within minutes following dural opening for resection of a posterior fossa meningioma. Results: In two patients with anterior cerebellopontine angle and clival meningiomas, there was a significant deterioration of the BAER soon after durotomy but prior to cerebellar retraction and tumor removal. Intracranial structures in the posterior fossa lying between the tumor and dural opening were shifted posteriorly after durotomy. Conclusion: We hypothesized that the cochlear nerve and vessels entering the acoustic meatus were compressed or stretched when subjected to tissue shift. This movement caused cochlear nerve dysfunction that resulted in BAER suppression. BAER was partially restored after the tumor was decompressed, dura repaired, and bone replaced. BAER was not suppressed following durotomy for removal of a meningioma lying posterior to the cochlear complex. Insight into the mechanisms of durotomy-induced BAER inhibition would allay the neurosurgeon's anxiety during the operation. PMID:25883849

  7. 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.

  8. Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

    PubMed Central

    Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

    2015-01-01

    Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

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

    PubMed Central

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

    2015-01-01

    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. PMID:26556349

  10. Differential effects of dopamine D2 and GABAA receptor antagonists on dopamine neurons between the anterior and posterior ventral tegmental area of female Wistar rats

    PubMed Central

    Ding, Zheng-Ming; Liu, Wen; Engleman, Eric A.; Rodd, Zachary A.; McBride, William J.

    2010-01-01

    Previous findings indicated differences in neuronal circuitries mediating drug reinforcement between the anterior and posterior ventral tegmental area (VTA). The objective of the present study was to examine the effects of the dopamine D2 antagonist sulpiride and the GABAA antagonist picrotoxin administered in the anterior and posterior VTA on the activity of mesoaccumbal dopamine neurons in female Wistar rats. Sulpiride and picrotoxin were administered in the anterior and posterior VTA. Extracellular dopamine levels were measured in sub-regions of the VTA and nucleus accumbens (ACB). Reverse-microdialysis of sulpiride (100 µM) into the posterior VTA increased extracellular dopamine levels locally (80% above baseline) and in the ACB shell and core (70% above baseline), whereas reverse-microdialysis into the anterior VTA produced a much smaller effect locally (30% above baseline) and in the ACB shell and core. In contrast, microinjection of picrotoxin (80 and 160 µM) into the anterior, but not posterior VTA, increased dopamine release in the ACB shell. The results suggest that dopamine neurons in the posterior VTA, compared to the anterior VTA, may be under greater D2 receptor-mediated tonic inhibition, whereas dopamine neurons in the anterior VTA, compared to the posterior VTA, may be under greater GABAA receptor-mediated tonic inhibition. PMID:19480073

  11. Vasectomy and its reversal.

    PubMed

    Belker, A M

    1985-12-01

    Techniques, results, complications, and medicolegal aspects of vasectomy are discussed in this article. Emphasis is placed on techniques that prevent spontaneous recanalization of the ends of the vas deferens after vasectomy. Factors that affect the reversibility of vasectomy are discussed. New microsurgical techniques of vasectomy reversal are described, and results of these new techniques are compared with results of nonmicrosurgical techniques of vasectomy reversal. Indications for bypass vasoepididymostomy during vasectomy reversal procedures, as well as techniques for performing vasoepididymostomy, are discussed.

  12. [Manual rotation of occiput posterior presentation].

    PubMed

    Le Ray, C; Goffinet, F

    2011-10-01

    Delivery in occiput posterior position is associated with a higher risk of cesarean section, operative vaginal delivery and severe perineal tears. We report the technic of manual rotation described by Tarnier and Chantreuil and used daily in our maternity center. Only five studies were published on this topic; all of them demonstrate that manual rotation decreases the risk of cesarean section. Moreover, it could decrease the risk of prolonged second stage, chorioamnionitis and third and fourth degree tears in comparison with expectant management. However, manual rotation is associated with a two-fold higher risk of cervical and vaginal lacerations. Manual rotation performed with an adequate technic is an efficient and safe manœuvre to avoid complications associated with occiput posterior vaginal delivery.

  13. Acute traumatic posterior elbow dislocation in children.

    PubMed

    Lieber, Justus; Zundel, Sabine M; Luithle, Tobias; Fuchs, Jörg; Kirschner, Hans-Joachim

    2012-09-01

    Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

  14. Posterior tibial nerve lesions in ankle arthroscopy.

    PubMed

    Cugat, Ramon; Ares, Oscar; Cuscó, Xavier; Garcia, Montserrat; Samitier, Gonzalo; Seijas, Roberto

    2008-05-01

    Ankle arthroscopy provides a minimally invasive approach to the diagnosis and treatment of certain ankle disorders. Neurological complications resulting from ankle arthroscopy have been well documented in orthopaedic and podiatric literature. Owing to the superficial location of the ankle joint and the abundance of overlying periarticular neurovascular structures, complications reported in ankle arthroscopy are greater than those reported for other joints. In particular, all reported neurovascular injuries following ankle arthroscopy have been the direct result of distractor pin or portal placement. The standard posteromedial portal has recognized risks because of the proximity of the posterior neurovascular structures. There can be considerable variability in the course of these portals and their proximity to the neurovascular structures. We found one report of intra-articular damage to the posterior tibial nerve as a result of ankle arthroscopy in the English-language literature and we report this paper as a second case described in the literature.

  15. Reverse Correlation in Neurophysiology

    ERIC Educational Resources Information Center

    Ringach, Dario; Shapley, Robert

    2004-01-01

    This article presents a review of reverse correlation in neurophysiology. We discuss the basis of reverse correlation in linear transducers and in spiking neurons. The application of reverse correlation to measure the receptive fields of visual neurons using white noise and m-sequences, and classical findings about spatial and color processing in…

  16. Progressive visual agnosia with posterior cortical atrophy.

    PubMed

    Mizuno, M; Sartori, G; Liccione, D; Battelli, L; Campo, R

    1996-05-01

    A patient of posterior cortical atrophy characterized by early signs of progressive visual agnosia documented by repeated neuropsychological tests, is reported. SPECT and MRI findings showed left unilateral parieto-occipital involvement in the earlier stage. A PET study executed eight months later showed bilateral parieto-occipital hypometabolism, but predominantly in the left hemisphere. This suggests that the degeneration may have developed asymmetrically, progressing from left unilateral to bilateral.

  17. Endoscopic posterior interhemispheric complete corpus callosotomy.

    PubMed

    Sood, Sandeep; Asano, Eishi; Altinok, Deniz; Luat, Aimee

    2016-12-01

    Traditionally corpus callosotomy is done through a craniotomy centered at the coronal suture, with the aid of a microscope. This involves dissecting through the interhemispheric fissure below the falx to reach the corpus callosum. The authors describe a posterior interhemispheric approach to complete corpus callosotomy with an endoscope, which bypasses the need to perform interhemispheric dissection because the falx is generally close to the corpus callosum in this region.

  18. Material Properties of the Posterior Human Sclera☆

    PubMed Central

    Grytz, Rafael; Fazio, Massimo A.; Girard, Michael J.A.; Libertiaux, Vincent; Bruno, Luigi; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2013-01-01

    To characterize the material properties of posterior and peripapillary sclera from human donors, and to investigate the macro- and micro-scale strains as potential control mechanisms governing mechanical homeostasis. Posterior scleral shells from 9 human donors aged 57–90 years were subjected to IOP elevations from 5 to 45 mmHg and the resulting full-field displacements were recorded using laser speckle interferometry. Eye-specific finite element models were generated based on experimentally measured scleral shell surface geometry and thickness. Inverse numerical analyses were performed to identify material parameters for each eye by matching experimental deformation measurements to model predictions using a microstructure-based constitutive formulation that incorporates the crimp response and anisotropic architecture of scleral collagen fibrils. The material property fitting produced models that fit both the overall and local deformation responses of posterior scleral shells very well. The nonlinear stiffening of the sclera with increasing IOP was well reproduced by the uncrimping of scleral collagen fibrils, and a circumferentially-aligned ring of collagen fibrils around the scleral canal was predicted in all eyes. Macroscopic in-plane strains were significantly higher in peripapillary region then in the mid-periphery. In contrast, the meso- and micro-scale strains at the collagen network and collagen fibril level were not significantly different between regions. The elastic response of the posterior human sclera can be characterized by the anisotropic architecture and crimp response of scleral collagen fibrils. The similar collagen fibril strains in the peripapillary and mid-peripheral regions support the notion that the scleral collagen architecture including the circumpapillary ring of collagen fibrils evolved to establish optimal load bearing conditions at the collagen fibril level. PMID:23684352

  19. Iris fixation of posterior chamber intraocular lenses.

    PubMed

    Yazdani-Abyaneh, Alireza; Djalilian, Ali R; Fard, Masoud Aghsaei

    2016-12-01

    We introduce a technique for iris fixation of a posterior chamber intraocular lens (IOL) in which most of the procedure is done outside the eye. This minimizes intraocular manipulation, maximizes corneal endothelial preservation, and avoids the risk for IOL drop into the vitreous cavity intraoperatively. The IOL is fixated to the most peripheral part of the iris, resulting in a rounder pupil. Sutures are placed at exact positions on the haptics, resulting in a well-centered IOL.

  20. 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

  1. Posterior fossa syndrome—a narrative review

    PubMed Central

    Wahab, Salima S.; Hettige, Samantha; Mankad, Kshtij

    2016-01-01

    Posterior fossa syndrome (PFS), or cerebellar mutism syndrome (CMS), is a collection of neurological symptoms that occur following surgical resection of a posterior fossa tumour, and is characterised by either a reduction or an absence of speech. Some authors suggest that CM is only one symptom of the CMS complex that also includes ataxia, hypotonia and irritability as well as cranial nerve deficits, neurobehavioral changes and urinary retention or incontinence. It is seen almost exclusively in children. In 1985 Rekate et al. published the first work describing CM as a clinical entity, occurring as a consequence of bilateral cerebellar injury. Other associated symptoms include visual impairment, altered mood, impaired swallowing and significant gross and fine motor deficits. The effects of this can have a devastating impact on both the patient and their carers, posing a significant clinical challenge to neurorehabilitation services. The reported incidence was between 8% and 31% of children undergoing surgery for posterior fossa tumour. The underlying pathologies include vasospasm, oedema, and axonal/neuronal injury. Neuroimaging has contributed to a better understanding of the anatomical location of postoperative injury. There have been a number of suggestions for treatment interventions for PFS. However, apart from some individual reports, there have been no clinical trials indicating possible benefit. Occupational therapy, speech and language therapy, as well as neurocognitive support, contribute to the recovery of these patients. PMID:27942479

  2. 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.

  3. 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.

  4. The eyeglass reversal.

    PubMed

    Oh, Songjoo

    2011-07-01

    Some figures, such as the Necker cube, are spontaneously reversible between alternative percepts. Before learning those skilled reversals, how do people achieve reversals for the very first time? It has been known that, in the case of a first reversal, people can be expected to see the reversal when given specific information about how the figures are ambiguous. This point was confirmed by using drawing versions of reversible figures. To demonstrate how intention plays a role in the initial reversal of a real object, a pair of regular eyeglasses, reversible in perspective, were presented to naïve observers in monocular vision. When the eyeglasses were viewed inwardly and the observers were given information that the eyeglasses could be ambiguous, they were able to easily see the reversal. When the eyeglasses were viewed outwardly, observers saw it only after they had been informed of exactly what the two alternative percepts were.Interestingly, many observers often mistakenly saw the inwardly viewed eyeglasses as placed outwardly from the beginning of the observation, while they saw the outwardly viewed eyeglasses correctly. Taking these results together, for the first reversal of a real object, the specificity of intention varies with the ambiguity of the object.

  5. Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse†

    PubMed Central

    Woo, Y. Joseph; MacArthur, John W.

    2013-01-01

    OBJECTIVES Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues. METHODS Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM. RESULTS Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well. CONCLUSION This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface. PMID:23449863

  6. Talar Osteochondroma Fracture Presenting as Posterior Ankle Impingement.

    PubMed

    Ercin, Ersin; Bilgili, Mustafa Gokhan; Gamsizkan, Mehmet; Avsar, Serdar

    2016-05-01

    Osteochondromas are the most common benign bone tumors. They are usually asymptomatic and found incidentally. When symptomatic, the symptoms are usually due to its location and size. Fracture of an osteochondroma presenting as posterior ankle impingement is a rare condition. We describe a 22-year-old man with solitary exostosis who presented with a posterior ankle mass and posterior ankle impingement with 2 years of follow-up. Surgical intervention was the treatment of choice in this patient, and histologic examination revealed a benign osteochondroma. Osteochondromas found in the posterior aspect of the talus can be complicated by fracture due to persistent motion of the ankle. Talar osteochondroma should be included in the differential diagnosis of posterior ankle impingement causes. Posterior talar osteochondromas, especially when a stalk is present, should be treated surgically before it is more complicated by a fracture and posterior ankle impingement.

  7. 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

  8. Surgical management of posterior fossa metastases.

    PubMed

    Sunderland, Geraint J; Jenkinson, Michael D; Zakaria, Rasheed

    2016-12-01

    The diagnosis of brain metastases is associated with a poor prognosis reflecting uncontrolled primary disease that has spread to the relative sanctuary of the central nervous system. 20 % of brain metastases occur in the posterior fossa and are associated with significant morbidity. The risk of acute hydrocephalus and potential for sudden death means these metastases are often dealt with as emergency cases. This approach means a full pre-operative assessment and staging of underlying disease may be neglected and a proportion of patients undergo comparatively high risk surgery with little or no survival benefit. This study aimed to assess outcomes in patients to identify factors that may assist in case selection. We report a retrospective case series of 92 consecutive patients operated for posterior fossa metastases between 2007 and 2012. Routine demographic data was collected plus data on performance status, primary cancer site, details of surgery, adjuvant treatment and survival. The only independent positive prognostic factors identified on multivariate analysis were good performance status (if Karnofsky performance score >70, hazard ratio (HR) for death 0.36, 95 % confidence interval (CI) 0.18-0.69), adjuvant whole brain radiotherapy (HR 0.37, 95 % CI 0.21-0.65) and adjuvant chemotherapy where there was extracranial disease and non-synchronous presentation (HR 0.51, 95 % CI 0.31-0.82). Patients presenting with posterior fossa metastases may not be investigated as thoroughly as those with supratentorial tumours. Staging and assessment is essential however, and in the meantime emergencies related to tumour mass effect should be managed with steroids and cerebrospinal fluid diversion as required.

  9. 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.

  10. [Posterior dislocation of the sternoclavicular joint].

    PubMed

    Mäkinen, Tatu; Madanat, Rami; Heinänen, Mikko; Brinck, Tuomas; Pajarinen, Jarkko

    2013-01-01

    Posterior dislocation of the sternoclavicular joint is a rare injury. It can be associated with life-threatening complications. Computed tomography is the imaging modality of choice with which possible associated injuries can be detected. Acute injuries are managed with closed reduction under general anaesthesia. A fracture-dislocation is inherently more unstable than an isolated dislocation. Surgical treatment is advocated in cases of delayed diagnosis or failed closed reduction. With early diagnosis and treatment, the long-term outcome of this injury is good.

  11. Perspective: reverse evolution.

    PubMed

    Teotónio, H; Rose, M R

    2001-04-01

    For some time, the reversibility of evolution was primarily discussed in terms of comparative patterns. Only recently has this problem been studied using experimental evolution over shorter evolutionary time frames. This has raised questions of definition, experimental procedure, and the hypotheses being tested. Experimental evolution has provided evidence for multiple population genetic mechanisms in reverse evolution, including pleiotropy and mutation accumulation. It has also pointed to genetic factors that might prevent reverse evolution, such as a lack of genetic variability, epistasis, and differential genotype-by-environment interactions. The main focus of this perspective is on laboratory studies and their relevance to the genetics of reverse evolution. We discuss reverse evolution experiments with Drosophila, bacterial, and viral populations. Field studies of the reverse evolution of melanism in the peppered moth are also reviewed.

  12. Reversible logic for supercomputing.

    SciTech Connect

    DeBenedictis, Erik P.

    2005-05-01

    This paper is about making reversible logic a reality for supercomputing. Reversible logic offers a way to exceed certain basic limits on the performance of computers, yet a powerful case will have to be made to justify its substantial development expense. This paper explores the limits of current, irreversible logic for supercomputers, thus forming a threshold above which reversible logic is the only solution. Problems above this threshold are discussed, with the science and mitigation of global warming being discussed in detail. To further develop the idea of using reversible logic in supercomputing, a design for a 1 Zettaflops supercomputer as required for addressing global climate warming is presented. However, to create such a design requires deviations from the mainstream of both the software for climate simulation and research directions of reversible logic. These deviations provide direction on how to make reversible logic practical.

  13. Decompression of Posterior Ankle Impingement With Concomitant Anterior Ankle Pathology by Posterior Ankle Arthroscopy in the Supine Position.

    PubMed

    Lui, Tun Hing

    2016-10-01

    Posterior ankle endoscopy is a safe and effective approach for treatment of posterior ankle impingement. This is usually performed with the patient in prone position. The purpose of this technical note is to describe an arthroscopic approach of decompression of posterior ankle impingement with the patient in supine position. This is indicated if there is posterior ankle impingement together with other ankle pathology requiring anterior ankle arthroscopy. This approach allows treatment of both anterior ankle and posterior ankle pathology with the patient in the supine position. Concomitant anterior ankle arthroscopy can be performed with the usual orientation without the need of change of patient's position.

  14. Traumatic posterior dislocation of hip in children.

    PubMed

    Kutty, S; Thornes, B; Curtin, W A; Gilmore, M F

    2001-02-01

    Traumatic posterior dislocation of the hip joint in children is an uncommon injury. It constitutes a true orthopedic emergency. It makes up over 80% of pediatric hip dislocations. In children, it can occur as a result of minimal trauma, which is attributed to a soft pliable acetabulum and ligamentous laxity. In skeletally mature adolescents, a greater force is required to dislocate the hip joint. Delay in reduction is associated with long-term complications such as avascular necrosis and degenerative arthritis. Avascular necrosis is related to the duration of dislocation. A poorer prognosis is associated with delay in reduction beyond 6 hours, advanced skeletal maturity, or multiple traumas. Prompt reduction minimizes complications. We report two cases of traumatic posterior dislocation of hip in children aged 3 and 14 years. Both were reduced within 6 hours of dislocation, and review at 6 months revealed normal examination and no evidence of any post-traumatic changes. Post-reduction treatment remains without a consensus. This review highlights the clinical presentation, management, and time-sensitive complications of the injury.

  15. Management of an Uncomplicated Posterior Elbow Dislocation

    PubMed Central

    Blackard, Douglas; Sampson, Jo-Ann

    1997-01-01

    Objective: To present a case of an uncomplicated posterior elbow dislocation in a US World Cup athlete and discuss her rehabilitation. Background: Traditional protocol for management of this injury has been splint immobilization for several weeks, but research suggests a shortened duration of immobilization and early active motion. Differential Diagnosis: Elbow dislocation with possible fracture. Treatment: The dislocation was reduced and a compression bandage and sling were applied. The sports medicine staff and athlete determined that rehabilitation would involve limited immobilization with a posterior splint. Also, active range-of- motion exercises were to be incorporated early in the range-of- motion program to decrease pain at the articulation. Uniqueness: The athlete was not immobilized and her aggressive five-phase rehabilitation program progressed according to decrease in inflammation and increase in range of motion and strength. Conclusions: Shortened immobilization and return to World Championship competition 6 weeks postinjury had no longterm adverse effects on the athlete. ImagesFig 1.Fig 2.Fig 3.Fig 4.Fig. 5. PMID:16558436

  16. Posterior malleolar fractures of the ankle.

    PubMed

    Bartoníček, J; Rammelt, S; Tuček, M; Naňka, O

    2015-12-01

    Despite an increasing awareness of injuries to PM in ankle fracture-dislocations, there are still many open questions. The mere presence of a posterior fragment leads to significantly poorer outcomes. Adequate diagnosis, classification and treatment require preoperative CT examination, preferably with 3D reconstructions. The indication for surgical treatment is made individually on the basis of comprehensive assessment of the three-dimensional outline of the PM fracture and all associated injuries to the ankle including syndesmotic instability. Anatomic fixation of the avulsed posterior tibiofibular ligament will contribute to syndesmotic stability and restore the integrity of the incisura tibiae thus facilitating anatomic reduction of the distal fibula. A necessary prerequisite is mastering of posterolateral and posteromedial approaches and the technique of direct reduction and internal fixation. Further clinical studies with higher numbers of patients treated by similar methods and evaluation of pre- and postoperative CT scans will be necessary to determine reliable prognostic factors associated with certain types of PM fractures and associated injuries to the ankle.

  17. Microsurgical anatomy of the posterior fossa cisterns.

    PubMed

    Matsuno, H; Rhoton, A L; Peace, D

    1988-07-01

    The microsurgical anatomy of the posterior fossa cisterns was examined in 15 cadavers using 3X to 40X magnification. Liliequist's membrane was found to split into two arachnoidal sheets as it spreads upward from the dorsum sellae: an upper sheet, called the diencephalic membrane, which attaches to the diencephalon at the posterior edge of the mamillary bodies, and a lower sheet, called the mesencephalic membrane, which attaches along the junction of the midbrain and pons. Several other arachnoidal membranes that separate the cisterns were identified. These include the anterior pontine membrane, which separates the prepontine and cerebellopontine cisterns; the lateral pontomesencephalic membrane, which separates the ambient and cerebellopontine cisterns; the medial pontomedullary membrane, which separates the premedullary and prepontine cisterns; and the lateral pontomedullary membrane, which separates the cerebellopontine and cerebellomedullary cisterns. The three cisterns in which the arachnoid trabeculae and membranes are the most dense and present the greatest obstacle at operation are the interpeduncular and quadrigeminal cisterns and the cisterna magna. Numerous arachnoid membranes were found to intersect the oculomotor nerves. The neural and vascular structures in each cistern are reviewed.

  18. Prehension Movements in a Patient (AC) with Posterior Parietal Cortex Damage and Posterior Callosal Section

    ERIC Educational Resources Information Center

    Frak, Victor; Paulignan, Yves; Jeannerod, Marc; Michel, Francois; Cohen, Henri

    2006-01-01

    Prehension movements of the right hand were recorded in a right-handed man (AC), with an injury to the left posterior parietal cortex (PPC) and with a section of the left half of the splenium. The kinematic analysis of AC's grasping movements in direct and perturbed conditions was compared to that of five control subjects. A novel effect in…

  19. 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.

  20. Visual input to the mouse lateral posterior and posterior thalamic nuclei: photoreceptive origins and retinotopic order

    PubMed Central

    Allen, Annette E.; Procyk, Christopher A.; Howarth, Michael; Walmsley, Lauren

    2016-01-01

    Key points The lateral posterior and posterior thalamic nuclei have been implicated in aspects of visually guided behaviour and reflex responses to light, including those dependent on melanopsin photoreception.Here we investigated the extent and basic properties of visually evoked activity across the mouse lateral posterior and posterior thalamus.We show that a subset of retinal projections to these regions derive from melanopsin‐expressing retinal ganglion cells and find many cells that exhibit melanopsin‐dependent changes in firing.We also show that subsets of cells across these regions integrate signals from both eyes in various ways and that, within the lateral posterior thalamus, visual responses are retinotopically ordered. Abstract In addition to the primary thalamocortical visual relay in the lateral geniculate nuclei, a number of other thalamic regions contribute to aspects of visual processing. Thus, the lateral posterior thalamic nuclei (LP/pulvinar) appear important for various functions including determining visual saliency, visually guided behaviours and, alongside dorsal portions of the posterior thalamic nuclei (Po), multisensory processing of information related to aversive stimuli. However, despite the growing importance of mice as a model for understanding visual system organisation, at present we know very little about the basic visual response properties of cells in the mouse LP or Po. Prompted by earlier suggestions that melanopsin photoreception might be important for certain functions of these nuclei, we first employ specific viral tracing to show that a subset of retinal projections to the LP derive from melanopsin‐expressing retinal ganglion cells. We next use multielectrode electrophysiology to demonstrate that LP and dorsal Po cells exhibit a variety of responses to simple visual stimuli including two distinct classes that express melanopsin‐dependent changes in firing (together comprising ∼25% of neurons we recorded). We also

  1. 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.

  2. 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.

  3. Polycythemia causing posterior segment vascular occlusions

    PubMed Central

    Ganesan, Suganeswari; Raman, Rajiv; Sharma, Tarun

    2017-01-01

    A 44-year-old male patient presented with features suggestive of transient central retinal artery occlusion (CRAO) followed by permanent CRAO and lateral posterior ciliary artery occlusion. He had diagnostic features of polycythemia vera (PV). When presented for the first time, the patient had features of ocular ischemia such as ocular pain, conjunctival congestion, and retinal opacification but with normal arm-to-retina time and normal arteriovenous transit time. During the second presentation, he had ocular pain, congested conjunctiva, retinal opacification, cherry red spot with box-carrying of retinal vessels, and choroidal infarct (Amalric's sign). He had lost light perception in that eye. Patients with polycythemia are prone to multifocal vascular occlusions and this can be the presenting feature in PV. A timely diagnosis and prompt management can prevent these repeated thromboembolic occlusive episodes. PMID:28298862

  4. 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.

  5. 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

  6. 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.

  7. An algebra of reversible computation.

    PubMed

    Wang, Yong

    2016-01-01

    We design an axiomatization for reversible computation called reversible ACP (RACP). It has four extendible modules: basic reversible processes algebra, algebra of reversible communicating processes, recursion and abstraction. Just like process algebra ACP in classical computing, RACP can be treated as an axiomatization foundation for reversible computation.

  8. Posterior tibial subluxation and short-term arthritis resulting from failed posterior cruciate ligament reconstruction.

    PubMed

    Mavrodontidis, Alexandros N; Papadonikolakis, Anastasios; Moebius, Ulf G; Gelalis, Ioannis; Motsis, Efstathios; Soucacos, Panayotis N

    2003-01-01

    Posterior tibial subluxations because of combined or isolated posterior cruciate ligament (PCL) injuries require detailed evaluation. PCL reconstructions are difficult procedures because of the low rate of such injuries and the complex anatomy of the ligament. We report on 2 cases of failed PCL reconstruction because of malpositioned femoral tunnels. These 2 cases support the existing biomechanical evidence that the correct placement of the tunnels, especially in the femur, is a major factor in defining the outcome. It seems that the drilling of the tunnels, especially in the femur, during PCL reconstruction must be performed with accuracy and always be evaluated in cases of graft failure. In addition, failed PCL reconstructions are usually accompanied by a short-term excessive arthritis that results in poor functional outcome.

  9. Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding.

    PubMed

    Calandrelli, Rosalinda; D'Apolito, Gabriella; Marco, Panfili; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-06-01

    This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects.PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV.Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume. The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS.

  10. Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding

    PubMed Central

    D’Apolito, Gabriella; Panfili, Marco; Zampino, Giuseppe; Tartaglione, Tommaso; Colosimo, Cesare

    2015-01-01

    This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects. PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV. Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS. PMID:26246091

  11. Generalizing Swendsen-Wang to sampling arbitrary posterior probabilities.

    PubMed

    Barbu, Adrian; Zhu, Song-Chun

    2005-08-01

    Many vision tasks can be formulated as graph partition problems that minimize energy functions. For such problems, the Gibbs sampler provides a general solution but is very slow, while other methods, such as Ncut and graph cuts are computationally effective but only work for specific energy forms and are not generally applicable. In this paper, we present a new inference algorithm that generalizes the Swendsen-Wang method to arbitrary probabilities defined on graph partitions. We begin by computing graph edge weights, based on local image features. Then, the algorithm iterates two steps. 1) Graph clustering: It forms connected components by cutting the edges probabilistically based on their weights. 2) Graph relabeling: It selects one connected component and flips probabilistically, the coloring of all vertices in the component simultaneously. Thus, it realizes the split, merge, and regrouping of a "chunk" of the graph, in contrast to Gibbs sampler that flips a single vertex. We prove that this algorithm simulates ergodic and reversible Markov chain jumps in the space of graph partitions and is applicable to arbitrary posterior probabilities or energy functions defined on graphs. We demonstrate the algorithm on two typical problems in computer vision--image segmentation and stereo vision. Experimentally, we show that it is 100-400 times faster in CPU time than the classical Gibbs sampler and 20-40 times faster then the DDMCMC segmentation algorithm. For stereo, we compare performance with graph cuts and belief propagation. We also show that our algorithm can automatically infer generative models and obtain satisfactory results (better than the graphic cuts or belief propagation) in the same amount of time.

  12. 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

  13. 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

  14. Grammont reverse prosthesis: design, rationale, and biomechanics.

    PubMed

    Boileau, Pascal; Watkinson, Duncan J; Hatzidakis, Armodios M; Balg, Frederic

    2005-01-01

    Combined destruction of the rotator cuff and the glenohumeral joint may lead to a painful and pseudo-paralyzed shoulder. In this situation a nonconstrained shoulder prosthesis yields a limited functional result or may even be contraindicated. Previous constrained prostheses (ball-and-socket or reverse ball-and-socket designs) have failed because their center of rotation remained lateral to the scapula, which limited motion and produced excessive torque on the glenoid component, leading to early loosening. The reverse prosthesis designed by Paul Grammont, unlike any previous reverse ball-and-socket design, has introduced 2 major innovations that have led to its success: (1) a large glenoid hemisphere with no neck and (2) a small humeral cup almost horizontally oriented with a nonanatomic inclination of 155 degrees, covering less than half of the glenosphere. This design medializes and stabilizes the center of rotation, minimizes torque on the glenoid component, and helps in recruiting more fibers of the anterior and posterior deltoid to act as abductors. Furthermore, the humerus is lowered relative to the acromion, restoring and even increasing deltoid tension. The Grammont reverse prosthesis imposes a new biomechanical environment for the deltoid muscle to act, thus allowing it to compensate for the deficient rotator cuff muscles. The clinical experience does live up to the biomechanical concept: the reverse prosthesis restores active elevation above 90 degrees in patients with a cuff-deficient shoulder. However, external rotation often remains limited, particularly in patients with an absent or fat-infiltrated teres minor. Internal rotation is also rarely restored after a reverse prosthesis. Failure to restore sufficient tension in the deltoid may result in prosthetic instability. The design does appear to protect against early loosening of the glenoid component, but impingement of the humeral cup on the scapular neck can lead to scapular notching and polyethylene

  15. Radial head fracture associated with posterior interosseous nerve injury.

    PubMed

    Terra, Bernardo Barcellos; Sassine, Tannus Jorge; Lima, Guilherme de Freitas; Rodrigues, Leandro Marano; Padua, David Victoria Hoffmann; Nadai, Anderson de

    2016-01-01

    Fractures of the radial head and radial neck correspond to 1.7-5.4% of all fractures and approximately 30% may present associated injuries. In the literature, there are few reports of radial head fracture with posterior interosseous nerve injury. This study aimed to report a case of radial head fracture associated with posterior interosseous nerve injury.

  16. 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.

  17. Wnt signaling and the evolution of embryonic posterior development.

    PubMed

    Martin, Benjamin L; Kimelman, David

    2009-03-10

    During vertebrate embryogenesis, most of the mesodermal tissue posterior to the head forms from a progenitor population that continuously adds blocks of muscles (the somites) from the back end of the embryo. Recent work in less commonly studied arthropods--the flour beetle Tribolium and the common house spider--provides evidence suggesting that this posterior growth process might be evolutionarily conserved, with canonical Wnt signaling playing a key role in vertebrates and invertebrates. We discuss these findings as well as other evidence that suggests that the genetic network controlling posterior growth was already present in the last common ancestor of the Bilateria. We also highlight other interesting commonalities as well as differences between posterior growth in vertebrates and invertebrates, suggest future areas of research, and hypothesize that posterior growth may facilitate evolution of animal body plans.

  18. Management of the posterior capsule during pediatric intraocular lens implantation.

    PubMed

    Buckley, E G; Klombers, L A; Seaber, J H; Scalise-Gordy, A; Minzter, R

    1993-06-15

    One of the major obstacles in pediatric intraocular lens implantation has been the subsequent dense opacification of the posterior capsule. We used a modification of the standard pediatric cataract surgical procedure, which involved endocapsular cataract extraction, posterior chamber intraocular lens implantation, pars plana posterior capsulotomy, and pars plana anterior vitrectomy in 20 consecutive patients with unilateral traumatic, radiation-induced, and developmental cataracts. Visual axes were rapidly restored in all patients without further intervention for posterior capsule opacification. Visual acuity returned to 20/40 or better in all patients and 75% of all patients (15 patients) reached maximum improvement by five weeks. No complications attributed to intraoperative removal of the posterior capsule occurred.

  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. 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

  1. Automatic quantification of posterior capsule opacification

    NASA Astrophysics Data System (ADS)

    Barman, Sarah A.; Uyyanonvara, Bunyarit; Boyce, James F.; Sanguinetti, Giorgia; Hollick, Emma J.; Meacock, William R.; Spalton, David J.; Paplinski, Andrew P.

    2000-06-01

    After Cataract surgery where a plastic implant lens is implanted into the eye to replace the natural lens, many patients suffer from cell growth across a membrane situated at the back of the lens which degrades their vision. The cell growth is known as Posterior Capsule Opacification (or PCO). It is important to be able to quantify PCO so that the effect of different implant lens types and surgical techniques may be evaluated. Initial results obtained using a neural network to detect PCO from implant lenses are compared to an established but less automated method of detection, which segments the images using texture segmentation in conjunction with co- occurrence matrices. Tests show that the established method performs well in clinical validation and repeatability trials. The requirement to use a neural network to analyze the implant lens images evolved from the analysis of over 1000 images using the established co-occurrence matrix segmentation method. The work shows that a method based on neural networks is a promising tool to automate the procedure of calculating PCO.

  2. Representation of numerosity in posterior parietal cortex

    PubMed Central

    Roitman, Jamie D.; Brannon, Elizabeth M.; Platt, Michael L.

    2012-01-01

    Humans and animals appear to share a similar representation of number as an analog magnitude on an internal, subjective scale. Neurological and neurophysiological data suggest that posterior parietal cortex (PPC) is a critical component of the circuits that form the basis of numerical abilities in humans. Patients with parietal lesions are impaired in their ability to access the deep meaning of numbers. Acalculiac patients with inferior parietal damage often have difficulty performing arithmetic (2 + 4?) or number bisection (what is between 3 and 5?) tasks, but are able to recite multiplication tables and read or write numerals. Functional imaging studies of neurologically intact humans performing subtraction, number comparison, and non-verbal magnitude comparison tasks show activity in areas within the intraparietal sulcus (IPS). Taken together, clinical cases and imaging studies support a critical role for parietal cortex in the mental manipulation of numerical quantities. Further, responses of single PPC neurons in non-human primates are sensitive to the numerosity of visual stimuli independent of low-level stimulus qualities. When monkeys are trained to make explicit judgments about the numerical value of such stimuli, PPC neurons encode their cardinal numerical value; without such training PPC neurons appear to encode numerical magnitude in an analog fashion. Here we suggest that the spatial and integrative properties of PPC neurons contribute to their critical role in numerical cognition. PMID:22666194

  3. Dynamic properties of the posterior cricoarytenoid muscle.

    PubMed

    Cooper, D S; Shindo, M; Sinha, U; Hast, M H; Rice, D H

    1994-12-01

    The aim of this research was to investigate the contractile properties of the posterior cricoarytenoid (PCA) muscle. Simultaneous measurements were made of the isometric force, temperature, and electromyographic activity of the dorsal cricoarytenoid muscle of anesthetized dogs during supramaximal stimulation of the recurrent laryngeal nerve for twitch and tetanic contraction. The conduction delay between stimulation of the recurrent nerve at the level of the larynx and the onset of the muscle action potential averaged 2.0 +/- 0.2 milliseconds (ms), and the latent period between the onset of electrical activity of the muscle and the onset of contraction had a mean duration of 3.3 +/- 0.8 ms. The mean of isometric contraction times found was 33.3 +/- 2.0 ms, shorter than most previous studies of canine PCA muscle. Tetanic frequency defined as smooth contraction was higher than previous estimates. Considerations of scaling of physiological time based on animal mass were applied to analysis of the experimental findings to make possible systematic comparison of previous findings across species and animal size.

  4. Ganglion cysts of the posterior cruciate ligament.

    PubMed

    Shetty, Gautam M; Nha, Kyung Wook; Patil, Sachin P; Chae, Dong Ju; Kang, Ki Hoon; Yoon, Jung Ro; Choo, Suk Kyu; Yi, Jeong Woo; Kim, Ji Hoon; Baek, Jong Ryoon

    2008-08-01

    Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals.

  5. Posterior Probability Matching and Human Perceptual Decision Making.

    PubMed

    Murray, Richard F; Patel, Khushbu; Yee, Alan

    2015-06-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models' performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  6. Mitral Valve Mechanics Following Posterior Leaflet Patch Augmentation

    PubMed Central

    Rahmani, Azadeh; Rasmussen, Ann Q.; Honge, Jesper L.; Ostli, Bjorn; Levine, Robert A.; Hagège, Albert; Nygaard, Hans; Nielsen, Sten L.; Jensen, Morten O.

    2013-01-01

    Background and aim of the study Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation. Methods Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 × 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted on the chordae tendineae. Data were acquired before and after 12 mm posterior and 5 mm apical posterior papillary muscle displacement to simulate the effect from one of the main contributors of FIMR, before and after patch augmentation. Results The effect of displacing the posterior papillary muscle induced tethering on the intermediate chordae tendineae to the posterior leaflet, and resulted in a 39.8% force increase (p = 0.014). Posterior leaflet patch augmentation of the FIMR valve induced a 31.1% force decrease (p = 0.007). There was no difference in force between the healthy and the repaired valve simulations (p = 0.773). Conclusion Posterior leaflet patch augmentation significantly reduced the forces exerted on the intermediate chordae tendineae from the posterior papillary muscle following FIMR simulation. As changes in chordal tension lead to a redistribution of the total stress exerted on the valve, patch augmentation may have an adverse long-term influence on mitral valve function and remodeling. PMID:23610985

  7. Posterior Probability Matching and Human Perceptual Decision Making

    PubMed Central

    Murray, Richard F.; Patel, Khushbu; Yee, Alan

    2015-01-01

    Probability matching is a classic theory of decision making that was first developed in models of cognition. Posterior probability matching, a variant in which observers match their response probabilities to the posterior probability of each response being correct, is being used increasingly often in models of perception. However, little is known about whether posterior probability matching is consistent with the vast literature on vision and hearing that has developed within signal detection theory. Here we test posterior probability matching models using two tools from detection theory. First, we examine the models’ performance in a two-pass experiment, where each block of trials is presented twice, and we measure the proportion of times that the model gives the same response twice to repeated stimuli. We show that at low performance levels, posterior probability matching models give highly inconsistent responses across repeated presentations of identical trials. We find that practised human observers are more consistent across repeated trials than these models predict, and we find some evidence that less practised observers more consistent as well. Second, we compare the performance of posterior probability matching models on a discrimination task to the performance of a theoretical ideal observer that achieves the best possible performance. We find that posterior probability matching is very inefficient at low-to-moderate performance levels, and that human observers can be more efficient than is ever possible according to posterior probability matching models. These findings support classic signal detection models, and rule out a broad class of posterior probability matching models for expert performance on perceptual tasks that range in complexity from contrast discrimination to symmetry detection. However, our findings leave open the possibility that inexperienced observers may show posterior probability matching behaviour, and our methods provide new tools

  8. Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis

    PubMed Central

    Torrens, Carlos; Corrales, Monica; Gonzalez, Gemma; Solano, Alberto; Cáceres, Enrique

    2008-01-01

    Purpose The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component. Methods Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column. Results The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50°–52°) and type II (mean 62,50°–64°), with significant differences between them (p < 0,001). The angle between the major craneo-caudal glenoid axis and the base of the coracoid process averaged 18,25° while the angle with the upper posterior column of the scapula averaged 8°. Conclusion Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation. PMID:18847487

  9. Effect of reverse shoulder design philosophy on muscle moment arms.

    PubMed

    Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

    2015-04-01

    This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively.

  10. Reversibility of liver fibrosis.

    PubMed

    Sun, Mengxi; Kisseleva, Tatiana

    2015-09-01

    Liver fibrosis is a serious health problem worldwide, which can be induced by a wide spectrum of chronic liver injuries. However, until today, there is no effective therapy available for liver fibrosis except the removal of underlying etiology or liver transplantation. Recent studies indicate that liver fibrosis is reversible when the causative agent(s) is removed. Understanding of mechanisms of liver fibrosis regression will lead to the identification of new therapeutic targets for liver fibrosis. This review summarizes recent research progress on mechanisms of reversibility of liver fibrosis. While most of the research has been focused on HSCs/myofibroblasts and inflammatory pathways, the crosstalk between different organs, various cell types and multiple signaling pathways should not be overlooked. Future studies that lead to fully understanding of the crosstalk between different cell types and the molecular mechanism underlying the reversibility of liver fibrosis will definitely give rise to new therapeutic strategies to treat liver fibrosis.

  11. Dynamics of magnetization reversal

    NASA Astrophysics Data System (ADS)

    Safonov, Vladimir L.

    2000-03-01

    Advanced magnetic recording systems are designed for extremely high areal densities and data rate. These two aspects require both magnetization reversal at very short times (< 1 ns) and long term ( ~ 5-10 years) stability against thermal fluctuations. There are two basic physics problems associated with these requirements. The first is a characterization of thermal-dynamic reversal over very wide time range. The second is an understanding of the physics of the relaxation mechanisms. Both these subjects will be reviewed in this talk. Thermal dynamic reversal requires solution of the Landau-Lifshitz equation with fluctuations. We have solved this problem in terms of the ``random walk" dynamics of a nonlinear oscillator [1,2]. The expressions for the switching field versus pulse time are analytic and show good agreement with measurements on CrO_2. Our studies of fundamental relaxation mechanisms have involved a two step approach. First the results of computer simulations of magnetization reversal without phenomenological damping will be discussed. In this case coherent rotation of the magnetization excites spin waves during which an excess of Zeeman energy is transformed to anisotropy and exchange energies. However, for fine grains whose size is sufficiently small so that the grain magnetization is virtually uniform, non-linear spin waves cannot assist reversal [3]. A new analytic model of reversal that couples coherent rotation to impurity ions by an anisotropic exchange mechanism will be discussed. These impurity ions are assumed to relax at a very high rate to the lattice. [1] V.L.Safonov, JMMM 195, 523 (1999); J.Appl.Phys. 85, 4370 (1999). [2] V.L.Safonov, H.N.Bertram, MMM'99, CU-09. [3] V.L.Safonov, H.N.Bertram, J.Appl.Phys. 85, 5072 (1999); MMM'99, CD-11.

  12. Posterior urethral valves: long-term outcome.

    PubMed

    Caione, Paolo; Nappo, Simona Gerocarni

    2011-10-01

    Posterior urethral valves represent the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function. Long-term outcome of patients with previous PUV is evaluated. Patients over 18 years of age, treated from 1982 to 1995 before the age of 3 years were considered. Previous surgery, renal function, bladder activity, urinary incontinence, and fertility/sexual activity were evaluated. Clinical interview, creatinine clearance, uroflowmetry with ultrasound post-void urine residue, and self-administered questionnaire were recorded. Out of 45 identified records, 24 patients (53.3%) accepted to be enrolled (age 18-34 years, mean 23 years). The mean follow-up was 19.5 years (16-30 years). Out of the 21 excluded patients, 20 did not reply to the clinical interview and 1 died at age of 6 years. All the 24 patients had early endoscopic section of PUV; nine also received transient ureterocutaneostomy or vesicostomy. Ureteroneocystostomy was performed in five patients and ureterocystoplasty with unilateral nephrectomy in two. At follow-up chronic renal failure was detected in 13 patients (54.1%) and 9 (37.5%) had arterial hypertension. End-stage renal disease developed in five patients (20.8%): three had successful renal transplantation and two were in dialysis. Lower urinary tract symptoms were present in seven patients (29.1%). No significant fertility deficit and sexual dysfunction were observed in 23 patients, while 1 patient was azoospermic. No paternity was reported so far. Long-term outcome of patients with previously treated PUV is mandatory. Kidney, bladder, and sexual functions should be monitored till adulthood to verify any modified behaviour.

  13. The language profile of Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J.; Lehmann, Manja; Warren, Jason D.; Rohrer, Jonathan D.

    2015-01-01

    Background Posterior Cortical Atrophy (PCA) is typically considered to be a visual syndrome, primarily characterised by progressive impairment of visuoperceptual and visuospatial skills. However patients commonly describe early difficulties with word retrieval. This paper details the first systematic analysis of linguistic function in PCA. Characterising and quantifying the aphasia associated with PCA is important for clarifying diagnostic and selection criteria for clinical and research studies. Methods Fifteen patients with PCA, 7 patients with logopenic/phonological aphasia (LPA) and 18 age-matched healthy participants completed a detailed battery of linguistic tests evaluating auditory input processing, repetition and working memory, lexical and grammatical comprehension, single word retrieval and fluency, and spontaneous speech. Results Relative to healthy controls, PCA patients exhibited language impairments across all the domains examined, but with anomia, reduced phonemic fluency and slowed speech rate the most prominent deficits. PCA performance most closely resembled that of LPA patients on tests of auditory input processing, repetition and digit span, but was relatively stronger on tasks of comprehension and spontaneous speech. Conclusions The study demonstrates that in addition to the well-reported degradation of vision, literacy and numeracy, PCA is characterised by a progressive oral language dysfunction with prominent word retrieval difficulties. Overlap in the linguistic profiles of PCA and LPA, which are both most commonly caused by Alzheimer’s disease, further emphasises the notion of a phenotypic continuum between typical and atypical manifestations of the disease. Clarifying the boundaries between AD phenotypes has important implications for diagnosis, clinical trial recruitment and investigations into biological factors driving phenotypic heterogeneity in AD. Rehabilitation strategies to ameliorate the phonological deficit in PCA are required

  14. 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

  15. 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.

  16. Origin of subcortical somatosensory evoked potentials in response to posterior tibial nerve stimulation in humans.

    PubMed

    Urasaki, E; Wada, S; Yokota, A; Tokimura, T; Yasukouchi, H

    1993-06-01

    To identify the origin of short latency somatosensory evoked potentials (SSEPs) to posterior tibial nerve stimulation, direct recordings were made from the cervical cord, the ventricular system and the frontal subcortex during 8 neurosurgical operations. The origin of each component of SSEPs was also studied in 7 selected patients with various lesions in the central nervous system. In addition, SSEPs to median nerve stimulation were investigated in 4 of 8 surgical cases and all 7 cases of the lesion study group. Bilateral posterior tibial nerve stimulation in 10 normal subjects showed spinal N28 on the skin of the posterior neck and far-field P30 and N33 components followed by a cortical P38 component at the scalp. Direct recordings made to the mid-brain through the medulla oblongata showed a negative potential with gradually increasing latency. The peak of the negativity in the vicinity of the dorsal column nucleus showed almost the same latency as that of the scalp far-field P30, and positivity with a stationary peak was found above the dorsal column nucleus. Above the mid-pons, there was a stationary negativity with no latency shift, showing the same peak latency as that of scalp N33. The spatiotemporal distributions of P30 and N33 to posterior tibial nerve stimulation were analogous to those of P14 and N18 by median nerve stimulation. Transesophageal and direct cervical cord recordings showed that the spinal N13 phase to median nerve stimulation was reversed between the dorsal and ventral sides of the cervical cord. No such reversal occurred for the spinal N28 potential. Clinical lesion studies showed that changes in P30 and P14, and in N33 and N18 correlated with one another: that is, 1) prolongation of latency of N33 was also observed for N18; 2) absence of P30 was paralleled by the absence of P14. These data suggest that spinal N28 originates from ascending activity such as a dorsal column volley, and scalp P30 comes from activity near the dorsal column

  17. Neural correlates of cognitive impairment in posterior cortical atrophy.

    PubMed

    Kas, Aurélie; de Souza, Leonardo Cruz; Samri, Dalila; Bartolomeo, Paolo; Lacomblez, Lucette; Kalafat, Michel; Migliaccio, Raffaella; Thiebaut de Schotten, Michel; Cohen, Laurent; Dubois, Bruno; Habert, Marie-Odile; Sarazin, Marie

    2011-05-01

    With the prospect of disease-modifying drugs that will target the physiopathological process of Alzheimer's disease, it is now crucial to increase the understanding of the atypical focal presentations of Alzheimer's disease, such as posterior cortical atrophy. This study aimed to (i) characterize the brain perfusion profile in posterior cortical atrophy using regions of interest and a voxel-based approach; (ii) study the influence of the disease duration on the clinical and imaging profiles; and (iii) explore the correlations between brain perfusion and cognitive deficits. Thirty-nine patients with posterior cortical atrophy underwent a specific battery of neuropsychological tests, mainly targeting visuospatial functions, and a brain perfusion scintigraphy with 99mTc-ethyl cysteinate dimer. The imaging analysis included a comparison with a group of 24 patients with Alzheimer's disease, matched for age, disease duration and Mini-Mental State Examination, and 24 healthy controls. The single-photon emission computed tomography profile in patients with posterior cortical atrophy was characterized by extensive and severe hypoperfusion in the occipital, parietal, posterior temporal cortices and in a smaller cortical area corresponding to the frontal eye fields (Brodmann areas 6/8). Compared with patients with Alzheimer's disease, the group with posterior cortical atrophy showed more severe occipitoparietal hypoperfusion and higher perfusion in the frontal, anterior cingulate and mesiotemporal regions. When considering the disease duration, the functional changes began and remained centred on the posterior lobes, even in the late stage. Correlation analyses of brain perfusion and neuropsychological scores in posterior cortical atrophy highlighted the prominent role of left inferior parietal damage in acalculia, Gerstmann's syndrome, left-right indistinction and limb apraxia, whereas damage to the bilateral dorsal occipitoparietal regions appeared to be involved in B

  18. Detection of Neisseria gonorrhoeae Isolates from Tonsils and Posterior Oropharynx

    PubMed Central

    Whiley, D. M.; Lee, D. M.; Snow, A. F.; Fairley, C. K.; Peel, J.; Bradshaw, C. S.; Hocking, J. S.; Lahra, M. M.; Chen, M. Y.

    2015-01-01

    We examined the factors influencing gonorrhea detection at the pharynx. One hundred men infected with Neisseria gonorrhoeae were swabbed from the tonsils and posterior oropharynx. N. gonorrhoeae was reisolated from the tonsils and posterior oropharynx in 62% and 52%, respectively (P = 0.041). Culture positivity was greater with higher gonococcal DNA loads at the tonsils (P = 0.001) and oropharynx (P < 0.001). N. gonorrhoeae can be cultured from the tonsils and posterior oropharynx with greater isolation rates where gonococcal loads are higher. PMID:26292303

  19. Immunopathology of the noninfectious posterior and intermediate uveitides.

    PubMed

    Boyd, S R; Young, S; Lightman, S

    2001-01-01

    The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

  20. 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.

  1. 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

  2. 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

  3. Ossification of the posterior longitudinal ligament: a case report

    PubMed Central

    Aker, PD; O’Connor, SM; Mior, SA; Beauchemin, D

    1989-01-01

    Ossification of the posterior longitudinal ligament (OPLL) has recently been recognized as a clinical entity. It is a rare condition, having a higher incidence in the Japanese population. It is characterized by hyperplasia of cartilage cells with eventual endochondral ossification of the posterior longitudinal ligament. The radiographic signs are characteristic and consist of a linear band of ossified tissue along the posterior margin of the vertebral body. OPLL can be associated with mild to serious neurological complications due to spinal cord or nerve root compression, or it may be asymptomatic. This paper reviews the radiological, clinical and therapeutic aspects of this rare condition. ImagesFigures 1 and 2Figures 3 and 4

  4. 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

  5. Reverse homeosis in homeotically reconstructed ribbonworms

    PubMed Central

    Tarpin, Michel; Gehring, Walter J.; Bièrne, Jacques

    1999-01-01

    Homeosis is the replacement of one body part by another, which may be caused by either developmental or genetic variations. It is particularly obvious in segmented animals, like insects, in which one body segment may be transformed into another. However, homeosis also occurs in animals without overt segmentation that also have detailed positional information specifying their body plan. By grafting, we have artificially generated homeotic ribbonworms of the species Lineus ruber with a duplicated ocellar region replacing the postocellar region anterior to the brain. Such chimeric animals are capable of complete morphogenetic regulation of the anterior–posterior (A–P) pattern. The missing postocellar region is restored by intercalary regeneration, and the anterior duplicated ocellar region is eliminated by a process called transgeneration. Thus, homeosis is reversed, and a completely normal pattern along the A–P axis is restored. This reverse homeosis involves the elimination of the syngeneic eyes and the survival of the grafted allogeneic eye region. LsPax-6, the Lineus sanguineus ortholog of the mammalian Pax-6 gene, which is considered to be a master control gene for eye morphogenesis, is expressed specifically in regenerating, regenerated, and intact eye regions. Our data show that ribbonworm eyes are either maintained or they regress according to their position along the A–P axis, even though there are no obvious segmental boundaries. This system allows us to test the function of LsPax-6 protein not only during eye regeneration but also during maintenance and regression of the eyes. PMID:10518548

  6. 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.

  7. 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.

  8. Tubal Ligation Reversal

    MedlinePlus

    ... depending on a woman's age and other factors. Success rates may be as high as 80 percent or ... details of the procedure Discuss the likelihood of success and your ability to get pregnant after the procedure Discuss other options for pregnancy, such as IVF A tubal ligation reversal can be done as ...

  9. Language Reversion Revisited.

    ERIC Educational Resources Information Center

    De Bot, Kees; Clyne, Michael

    1989-01-01

    A longitudinal study on language maintenance and loss among Dutch-English bilinguals in Australia revealed little loss in both languages over the years. This leads to the hypothesis of a "critical threshold" that must be reached to retain the second language. First language reversion appears commonly among immigrants who did not reach this…

  10. Rhinocerebral mucormycosis with extension to the posterior fossa: case report.

    PubMed

    Soloniuk, D S; Moreland, D B

    1988-11-01

    A 25-year-old man with juvenile onset diabetes presented with rhinoorbital mucormycosis. He was treated aggressively with orbital extirpation and amphotericin B. Six months later, he presented with posterior fossa extension of the mucormycosis.

  11. Modified posterior vertebral column resection for Kümmell disease

    PubMed Central

    Liu, Feng-Yu; Huo, Li-Shuang; Liu, Sen; Wang, Hui; Zhang, Li-Jun; Yang, Da-Long; Ding, Wen-Yuan

    2017-01-01

    Abstract Rationale: Kümmell's disease is defined as delayed traumatic vertebral collapse disease in which patients develop a kyphosis after asymptomatic minor spinal trauma. Both anterior approach and posterior approach have been reported, however, there is no standard treatment for Kümmell's disease. Patient concerns: We described a successful modified posterior vertebral column resection in a patient with Kümmell's disease. A 65-year-old woman reported persistent back pain for almost three months. Diagnoses: Kümmell's disease was diagnosed based on computer tomography (CT) and magnetic resonance imaging (MRI). Interventions: Modified posterior vertebral column resection combined with short-segment fixation was designed to treat this disease. Outcomes: The procedure was successful without any complications. Patient reported that symptoms were obviously improved in one week after operation. Lessons: Modified posterior vertebral column resection combined with short-segment fixation is an effective treatment option for Kümmell's disease. PMID:28151882

  12. Aneurysms of the posterior cerebral artery in children.

    PubMed

    Romero, F J; Tàpies, C; Ibarra, B; Rovira, M

    1988-01-01

    Two cases of aneurysms of the posterior cerebral artery, diagnosed by CT and confirmed angiographically, are reported. In the first case, the aneurysm was discovered fortuitously. The second began with intracerebral haemorrhage. A review of the literature is reported.

  13. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery.

    PubMed

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-12-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as "resection at an anterior site of the spinal cord from a posterior approach" (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

  14. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery

    PubMed Central

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-01-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis. PMID:27853667

  15. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    PubMed

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal 'visual dementia' and most common atypical Alzheimer's disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients' (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer's disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer's disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer's disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with 'sticky fixation'. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer's disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large saccadic intrusions

  16. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy

    PubMed Central

    Kaski, Diego; Yong, Keir X. X.; Paterson, Ross W.; Slattery, Catherine F.; Ryan, Natalie S.; Schott, Jonathan M.; Crutch, Sebastian J.

    2015-01-01

    The clinico-neuroradiological syndrome posterior cortical atrophy is the cardinal ‘visual dementia’ and most common atypical Alzheimer’s disease phenotype, offering insights into mechanisms underlying clinical heterogeneity, pathological propagation and basic visual phenomena (e.g. visual crowding). Given the extensive attention paid to patients’ (higher order) perceptual function, it is surprising that there have been no systematic analyses of basic oculomotor function in this population. Here 20 patients with posterior cortical atrophy, 17 patients with typical Alzheimer’s disease and 22 healthy controls completed tests of fixation, saccade (including fixation/target gap and overlap conditions) and smooth pursuit eye movements using an infrared pupil-tracking system. Participants underwent detailed neuropsychological and neurological examinations, with a proportion also undertaking brain imaging and analysis of molecular pathology. In contrast to informal clinical evaluations of oculomotor dysfunction frequency (previous studies: 38%, current clinical examination: 33%), detailed eyetracking investigations revealed eye movement abnormalities in 80% of patients with posterior cortical atrophy (compared to 17% typical Alzheimer’s disease, 5% controls). The greatest differences between posterior cortical atrophy and typical Alzheimer’s disease were seen in saccadic performance. Patients with posterior cortical atrophy made significantly shorter saccades especially for distant targets. They also exhibited a significant exacerbation of the normal gap/overlap effect, consistent with ‘sticky fixation’. Time to reach saccadic targets was significantly associated with parietal and occipital cortical thickness measures. On fixation stability tasks, patients with typical Alzheimer’s disease showed more square wave jerks whose frequency was associated with lower cerebellar grey matter volume, while patients with posterior cortical atrophy showed large

  17. The influence of posterior occlusion when restoring anterior teeth.

    PubMed

    Reshad, Mamaly; Jivraj, Sajid

    2008-08-01

    When any type of esthetic restorative procedure is being considered or performed, a comprehensive diagnosis and treatment plan is required. Attention to the diagnostic signs of the loss of posterior support (LPS) and their influence on the anterior dentition will guarantee a more predictable outcome. Historical solutions and their inadequacies are addressed. Patient presentations are utilized to demonstrate contemporary treatment of patients requiring esthetic rehabilitations who are lacking posterior support.

  18. 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. PMID:27709081

  19. [Tuberculosis of the posterior vertebral arch. A case report].

    PubMed

    Nassar, I; Mahi, M; Semlali, S; Kacemi, L; El Quessar, A; Chakir, N; El Hassani, M R; Jiddane, M

    2002-09-01

    Tuberculosis of the spine usually involves the vertebral body and intervertebral disk. Involvement of the posterior arch is rare. We report a case of tuberculosis involving the posterior elements of the T4 and T5 vertebrae in a 38 year old woman. CT is helpful to assess bony structures whereas MRI is ideal to evaluate the neural structures. Clinical, radiographic, and therapeutic considerations regarding tuberculosis of the spine are reviewed.

  20. Posterior polymorphous dystrophy and keratoglobus in a child.

    PubMed

    Patel, Sangita P; Sajnani, Manoj M; Pineda, Roberto

    2011-01-01

    A 13-year-old boy presented with gradually progressive deterioration of vision in both eyes, bilateral photophobia, and regular headaches. Clinical examination, anterior segment findings, and specular microscopy findings were consistent with the diagnosis of posterior polymorphous dystrophy and keratoglobus. To the authors' knowledge, this is the first pediatric case and the second case overall of the simultaneous occurrence of posterior polymorphous dystrophy and keratoglobus.

  1. Imaging in spinal posterior epidural space lesions: A pictorial essay.

    PubMed

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

  2. 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

  3. Imaging in spinal posterior epidural space lesions: A pictorial essay

    PubMed Central

    Gala, Foram B; Aswani, Yashant

    2016-01-01

    Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication. PMID:27857455

  4. 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.

  5. 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

  6. URCHIN: Reverse ray tracer

    NASA Astrophysics Data System (ADS)

    Altay, Gabriel; Theuns, Tom

    2014-12-01

    URCHIN is a Smoothed Particle Hydrodynamics (SPH) reverse ray tracer (i.e. from particles to sources). It calculates the amount of shielding from a uniform background that each particle experiences. Preservation of the adaptive density field resolution present in many gas dynamics codes and uniform sampling of gas resolution elements with rays are two of the benefits of URCHIN; it also offers preservation of Galilean invariance, high spectral resolution, and preservation of the standard uniform UV background in optically thin gas.

  7. Reversing Glass Wettability

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Smith, J. E., Jr.; Kaukler, W. F.

    1985-01-01

    Treatment reverses wettability of glassware: Liquids that normally wet glass no longer do, and those that do not wet glass are made to do so. Useful in research on container effects in nucleation and growth of secondary phase from solution. Treatment consists of spreading 3 percent (by weight) solution of silicone oil in hexane isomers over glass, drying in air, and curing at 300 degrees C in vacuum for one hour.

  8. Time reversal interactive objects

    NASA Astrophysics Data System (ADS)

    Ing, Ros Ki; Quieffin, Nicolas; Catheline, Stefan; Fink, Mathias

    2001-05-01

    Time reversal has shown to be a fruitful concept in nondestructive testing in underwater acoustic or in ultrasonic imaging. In this paper this technique is adapted in the audible range to transform every day objects into tactile sensitive interfaces. A quick historical background is presented in the ultrasonic field and specially in chaotic cavity. In all time reversal experiments, it is demonstrated that a wave field spatially and temporally recorded is able to back propagate to its source. In other words, the field contains all the information on the location of the source. In the interactive experiments, it is shown that touching an object like a window, a table or a world globe generates an acoustic field easily detectable with one or two acoustic sensors. Using the concept of time reversal, the source location is deduced in real time. Then, touching objects at specific locations (virtual switches) is used to activate devices. Such devices are for example lights, stereo volume, or computer software. From a technical point of view, all these interactive experiments just use some computation easily performed with a standard personnel computer.

  9. Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

    PubMed Central

    Huang, Yun-Peng; Du, Cheng-Fei; Cheng, Cheng-Kung; Zhong, Zheng-Cheng; Chen, Xuan-Wei; Wu, Gui; Li, Zhe-Cheng; Ye, Jin-Duo; Lin, Jian-Hua; Wang, Li Zhen

    2016-01-01

    Objective To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries. Methods A finite element model of the L1–S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.5-N.m moment of flexion, extension, torsion, and lateral bending. The range of motion (ROM), intradiscal pressure (IDP), and ligament force were compared. Results In Flexion, the ROM, IDP and ligament force of posterior longitudinal ligament, intertransverse ligament, and capsular ligament remarkably increased at the proximal adjacent segment in the PLIF-LAM model, and slightly increased in the PLIF-HEMI model. There was almost no difference for the ROM, IDP and ligament force at L5-S1 level between the two PLIF models although the ligament forces of ligamenta flava remarkably increased compared with the intact lumbar spine (INT) model. For the other loading conditions, these two models almost showed no difference in ROM, IDP and ligament force on the adjacent discs. Conclusions Preserved posterior complex acts as the posterior tension band during PLIF surgery and results in less ROM, IDP and ligament forces on the proximal adjacent segment in flexion. Preserving the posterior complex during decompression can be effective on preventing adjacent segment degeneration (ASD) following PLIF surgeries. PMID:27870867

  10. Posterolateral versus posterior interbody fusion in isthmic spondylolisthesis.

    PubMed

    Farrokhi, Majid Reza; Rahmanian, Abdolkarim; Masoudi, Mohammad Sadegh

    2012-05-20

    Spondylolisthesis is a heterogeneous disorder characterized by subluxation of a vertebral body over another in the sagittal plane. Its most common form is isthmic spondylolisthesis (IS). This study aims to compare clinical outcomes of posterolateral fusion (PLF) with posterior lumbar interbody fusion (PLIF) with posterior instrumentation in the treatment of IS. We performed a randomized prospective study in which 80 patients out of a total of 85 patients with IS were randomly allocated to one of two groups: PLF with posterior instrumentation (group I) or PLIF with posterior instrumentation (group II). Posterior decompression was performed in the patients. The Oswestry low back pain disability (OLBP) scale and Visual Analogue Scale (VAS) were used to evaluate the quality of life (QoL) and pain, respectively. Fisher's exact test was used to evaluate fusion rate and the Mann-Whitney U test was used to compare categorical data. Fusion in group II was significantly better than in group I (p=0.012). Improvement in low back pain was statistically more significant in group I (p=0.001). The incidence of neurogenic claudication was significantly lower in group I than in group II (p=0.004). In group I, there was no significant correlation between slip Meyerding grade and disc space height, radicular pain, and low back pain. There was no significant difference in post-operative complications at 1-year follow-up. Our data showed that PLF with posterior instrumentation provides better clinical outcomes and more improvement in low back pain compared to PLIF with posterior instrumentation despite the low fusion rate.

  11. Interoceptive awareness changes the posterior insula functional connectivity profile.

    PubMed

    Kuehn, Esther; Mueller, Karsten; Lohmann, Gabriele; Schuetz-Bosbach, Simone

    2016-04-01

    Interoceptive awareness describes the ability to consciously perceive inner bodily signals, such as one's own heartbeat. The right anterior insula is assumed to mediate this ability. The role of the posterior insula, particularly posterior-to-anterior insula signal flows is less clear in this respect. We scanned 27 healthy people with either high or low interoceptive awareness using 3T fMRI, while they either monitored their own heartbeats, or external tones, respectively. We used a combination of network centrality and bivariate connectivity analyses to characterize changes in cortical signal flows between the posterior insula and the anterior insula during interoceptive awareness or exteroceptive awareness, respectively. We show that heartbeat monitoring was accompanied by reduced network centrality of the right posterior insula, and decreased functional connectivity strengths between the right posterior insula and the right mid and anterior insula. In addition, decreased signal flows between the right posterior insula and the bilateral anterior cingulate cortices, and the bilateral orbitofrontal cortices were observed during interoceptive awareness. Functional connectivity changes were only shown by people with high interoceptive awareness, and occurred specifically within the low-frequency range (i.e., <0.1 Hz). Both groups did not differ in their functional connectivity profiles during rest. Our results show for the first time that interoceptive awareness changes intra-insula signal flows in the low-frequency range. We speculate that the selective inhibition of slow signal progression along the posterior-to-anterior insula pathway during interoceptive awareness allows the salient and noiseless detection of one's own heartbeat.

  12. Posterior scissors-bite: masticatory jaw movement and muscle activity.

    PubMed

    Tomonari, H; Kubota, T; Yagi, T; Kuninori, T; Kitashima, F; Uehara, S; Miyawaki, S

    2014-04-01

    Scissors-bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case-control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors-bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors-bite malocclusion and 18 subjects with normal occlusion in a case-control study. The chewing pattern on the scissors-bite side significantly differed from that of the non-scissors-bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0.01; cycle width, P < 0.01), a longer closing duration (P < 0.05), a slower closing velocity (P < 0.01) and lower activities of both the temporalis (P < 0.05) and the masseter (P < 0.05) muscles on the working side. In 96% of the patients with unilateral posterior scissors-bite, the preferred chewing side was the non-scissors-bite side (P = 0.005). These findings suggest that scissors-bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors-bite.

  13. 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

  14. Reversible brazing process

    DOEpatents

    Pierce, Jim D.; Stephens, John J.; Walker, Charles A.

    1999-01-01

    A method of reversibly brazing surfaces together. An interface is affixed to each surface. The interfaces can be affixed by processes such as mechanical joining, welding, or brazing. The two interfaces are then brazed together using a brazing process that does not defeat the surface to interface joint. Interfaces of materials such as Ni-200 can be affixed to metallic surfaces by welding or by brazing with a first braze alloy. The Ni-200 interfaces can then be brazed together using a second braze alloy. The second braze alloy can be chosen so that it minimally alters the properties of the interfaces to allow multiple braze, heat and disassemble, rebraze cycles.

  15. Reversal bending fatigue testing

    DOEpatents

    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.

  16. Treatment of noninfectious posterior uveitis with dexamethasone intravitreal implant

    PubMed Central

    Myung, Jane S; Aaker, Grant D; Kiss, Szilárd

    2010-01-01

    Purpose To report our experience with dexamethasone 0.7 mg sustained-release intravitreal implant (Ozurdex®; Allergan, Inc, Irvine, CA) in noninfectious posterior uveitis. Methods A retrospective chart review of patients with noninfectious uveitis treated with sustained-release dexamethasone 0.7 mg intravitreal implant was performed. Complete ophthalmic examination including signs of inflammatory activity, visual acuity, fundus photography, fluorescein angiography, optical coherence tomography, and tolerability of the implant were assessed. Results Six eyes of 4 consecutive patients treated with a total of 8 dexamethasone 0.7 mg sustained-release intravitreal implants for posterior noninfectious uveitis were included. Two patients presented with unilateral idiopathic posterior uveitis; 2 patients had bilateral posterior uveitis, one secondary to sarcoidosis and the other to Vogt-Koyanagi-Harada syndrome. All eyes showed clinical and angiographic evidence of decreased inflammation following implant placement. Mean follow-up time post-injection was 5.25 months. Four eyes received 1 and 2 eyes received 2 Ozurdex implants during the follow-up period. The duration of effect of the implant was 3 to 4 months. No serious ocular or systemic adverse events were noted during the follow-up period. Conclusions In patients with noninfectious posterior uveitis, sustained-release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option for controlling intraocular inflammation. PMID:21188153

  17. 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

  18. Arthroscopic subtalar arthrodesis: the posterior approach in the prone position.

    PubMed

    Carro, Luis Perez; Golanó, Pau; Vega, Jordi

    2007-04-01

    Arthroscopic subtalar arthrodesis, as reported by Tasto, is done in the lateral decubitus position, and the portal sites are lateral. This report describes a new alternative method in which the patient is in the prone position and a posterior 2-portal approach is used, as described by van Dijk et al. The initial debridement and synovectomy are performed with 4- and 5-mm resectors. Debridement and decortication are done posterior to the interosseous ligament because only the posterior facet is fused. Denudation of the articular surfaces is performed with curettes, as well as 4.5- and 5.5-mm burs, to remove 2 mm of subchondral bone. Stabilization in 5 degrees of hindfoot valgus is accomplished with 2 percutaneous cannulated headless screws from the non-weight-bearing portion of the calcaneal tuberosity directed to a point 5 to 10 mm posterior to the anterior margin of the posterior facet. The advantages of this alternative treatment are better intra-articular visualization, more thorough preparation of the fusion site, and minimal bone removal of the lateral side with better control of the arthrodesis position and with less chance of malunion, as well as the possibility to perform a concomitant surgical fusion or debridement of the ankle joint during the same operative procedure with no need for additional portals or orientation.

  19. Instrumented Posterior Lumbar Interbody Fusion in Adult Spondylolisthesis

    PubMed Central

    Yu, Ching-Hsiao; Wang, Chen-Ti

    2008-01-01

    It is unclear whether using artificial cages increases fusion rates compared with use of bone chips alone in posterior lumbar interbody fusion for patients with lumbar spondylolisthesis. We hypothesized artificial cages for posterior lumbar interbody fusion would provide better clinical and radiographic outcomes than bone chips alone. We assumed solid fusion would provide good clinical outcomes. We clinically and radiographically followed 34 patients with spondylolisthesis having posterior lumbar interbody fusion with mixed autogenous and allogeneic bone chips alone and 42 patients having posterior lumbar interbody fusion with implantation of artificial cages packed with morselized bone graft. Patients with the artificial cage had better functional improvement in the Oswestry disability index than those with bone chips alone, whereas pain score, patient satisfaction, and fusion rate were similar in the two groups. Postoperative disc height ratio, slip ratio, and segmental lordosis all decreased at final followup in the patients with bone chips alone but remained unchanged in the artificial cage group. The functional outcome correlated with radiographic fusion status. We conclude artificial cages provide better functional outcomes and radiographic improvement than bone chips alone in posterior lumbar interbody fusion for lumbar spondylolisthesis, although both techniques achieved comparable fusion rates. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18846411

  20. Biochemical and Clinical Assessments of Segmental Maxillary Posterior Tooth Intrusion

    PubMed Central

    Tasanapanont, Jintana; Wattanachai, Tanapan; Apisariyakul, Janya; Pothacharoen, Peraphan; Kongtawelert, Prachya; Midtbø, Marit

    2017-01-01

    Objective. To compare chondroitin sulphate (CS) levels around maxillary second premolars, first molars, and second molars between the unloaded and the loaded periods and to measure the rates of intrusion of maxillary posterior teeth during segmental posterior tooth intrusion. Materials and Methods. In this prospective clinical study, 105 teeth (from 15 patients exhibiting anterior open bite and requiring maxillary posterior tooth intrusion) were studied. Competitive ELISA was used to detect CS levels. Dental casts (during the unloaded and loaded periods) were scanned, and posterior tooth intrusion distances were measured. Results. During the unloaded period, the median CS levels around maxillary second premolars, first molars, second molars (experimental teeth), and mandibular first molars (negative control) were 0.006, 0.055, 0.056, and 0.012 and during the loaded period were 2.592, 5.738, 4.727, and 0.163 ng/μg of total protein, respectively. The median CS levels around experimental teeth were significantly elevated during the loaded period. The mean rates of maxillary second premolar and first and second molar intrusion were 0.72, 0.58, and 0.40 mm/12 weeks, respectively. Conclusions. Biochemical and clinical assessments suggested that the segmental posterior tooth intrusion treatment modality with 50 g of vertical force per side was sufficient. Trial Registration. The study is registered as TCTR20170206006. PMID:28321256

  1. Sural artery perforator flap with posterior tibial neurovascular decompression for recurrent foot ulcer in leprosy patients

    PubMed Central

    Ismail, Hossam El-din Ali; El Fahar, Mohamed Hassan

    2017-01-01

    Introduction: The sensory loss and alteration of the shape of the foot make the foot liable to trauma and pressure, and subsequently cause more callus formation, blisters, and ulcers. Foot ulcers usually are liable to secondary infection as cellulitis or osteomyelitis, and may result in amputations. Foot ulcers are a major problem and a major cause of handicaps in leprosy patients. The current study is to present our clinical experience and evaluate the use of sural flap with posterior tibial neurovascular decompression (PTND) in recurrent foot ulcers in leprosy patients. Patient and methods: A total number of 9 patients were suffering from chronic sequelae of leprosy as recurrent foot ulcers. All the patients were reconstructed with the reverse sural artery fasciocutaneous flap with posterior tibial neurovascular decompression from September 2012 to August 2015. Six patients were male and three were female with a mean age of 39.8 years (range, 30–50 years). All the soft tissue defects were in the weight-bearing area of the inside of the foot. The flap sizes ranged from 15/4 to 18/6 cm. Mean follow-up period was 21.2 months (range, 35–2 months). Results: All the flaps healed uneventfully. There was no major complication as total flap necrosis. Only minor complications occurred which were treated without surgical intervention except in two patients who developed superficial necrosis of the skin paddle. Surgical debridement was done one week later. The flap was completely viable after surgery, and the contour of the foot was restored. We found that an improvement of sensation occurred in those patients in whom the anesthesia started one year ago or less and no sensory recovery in patient in whom the anesthesia had lasted for more than two years. Conclusion: The reverse sural artery flap with posterior tibial neurovascular decompression provides a reliable method for recurrent foot soft tissue reconstruction in leprosy patients with encouraging function and

  2. 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…

  3. Reverse engineering molecular hypergraphs.

    PubMed

    Rahman, Ahsanur; Poirel, Christopher L; Badger, David J; Estep, Craig; Murali, T M

    2013-01-01

    Analysis of molecular interaction networks is pervasive in systems biology. This research relies almost entirely on graphs for modeling interactions. However, edges in graphs cannot represent multiway interactions among molecules, which occur very often within cells. Hypergraphs may be better representations for networks having such interactions, since hyperedges can naturally represent relationships among multiple molecules. Here, we propose using hypergraphs to capture the uncertainty inherent in reverse engineering gene-gene networks. Some subsets of nodes may induce highly varying subgraphs across an ensemble of networks inferred by a reverse engineering algorithm. We provide a novel formulation of hyperedges to capture this uncertainty in network topology. We propose a clustering-based approach to discover hyperedges. We show that our approach can recover hyperedges planted in synthetic data sets with high precision and recall, even for moderate amount of noise. We apply our techniques to a data set of pathways inferred from genetic interaction data in S. cerevisiae related to the unfolded protein response. Our approach discovers several hyperedges that capture the uncertain connectivity of genes in relevant protein complexes, suggesting that further experiments may be required to precisely discern their interaction patterns. We also show that these complexes are not discovered by an algorithm that computes frequent and dense subgraphs.

  4. Reversal of sterilisation.

    PubMed

    Cartwright, A

    1977-09-03

    It is difficult to know what conclusions one can reach in a study of 103 women who asked for reversal of sterilization (Mr. R.M.L. Winston, July 30, p. 305) when there are no data about the numbers and characteristics of the women who were sterilized and have not asked for reversal. And Mr. Winston's conclusion that it "seems unwise to sterilise women under 30 particularly immediately after pregnancy or if their marriage is in jeopardy" is therefore difficult to justify and has a disconcertingly paternalistic ring. It also implies that the stability or otherwise of a marriage should be a prime concern of obstetricians when women request sterilization. But what distrubed me most about Mr. Winston's article was his statement that "most women in this survey had been told that termination would not be undertaken without sterilisation." I wonder if this form of ultimatum, which Mr. Winston condemns, is likely to increase now that this operation is performed under a fee-for-service system?

  5. Subjective experience, involuntary movement, and posterior alien hand syndrome

    PubMed Central

    Bundick, T; Spinella, M

    2000-01-01

    The alien hand syndrome, as originally defined, was used to describe cases involving anterior corpus callosal lesions producing involuntary movement and a concomitant inability to distinguish the affected hand from an examiner's hand when these were placed in the patient's unaffected hand. In recent years, acceptable usage of the term has broadened considerably, and has been defined as involuntary movement occurring in the context of feelings of estrangement from or personification of the affected limb or its movements. Three varieties of alien hand syndrome have been reported, involving lesions of the corpus callosum alone, the corpus callosum plus dominant medial frontal cortex, and posterior cortical/subcortical areas. A patient with posterior alien hand syndrome of vascular aetiology is reported and the findings are discussed in the light of a conceptualisation of posterior alien hand syndrome as a disorder which may be less associated with specific focal neuropathology than are its callosal and callosal-frontal counterparts.

 PMID:10601408

  6. Local estimation of posterior class probabilities to minimize classification errors.

    PubMed

    Guerrero-Curieses, Alicia; Cid-Sueiro, Jesús; Alaiz-Rodríguez, Rocío; Figueiras-Vidal, Aníbal R

    2004-03-01

    Decision theory shows that the optimal decision is a function of the posterior class probabilities. More specifically, in binary classification, the optimal decision is based on the comparison of the posterior probabilities with some threshold. Therefore, the most accurate estimates of the posterior probabilities are required near these decision thresholds. This paper discusses the design of objective functions that provide more accurate estimates of the probability values, taking into account the characteristics of each decision problem. We propose learning algorithms based on the stochastic gradient minimization of these loss functions. We show that the performance of the classifier is improved when these algorithms behave like sample selectors: samples near the decision boundary are the most relevant during learning.

  7. ‘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

  8. 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.

  9. 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.

  10. Ligamentous and capsular restraints to experimental posterior elbow joint dislocation.

    PubMed

    Deutch, Søren R; Olsen, Bo S; Jensen, Steen L; Tyrdal, Stein; Sneppen, Otto

    2003-10-01

    Pathological external forearm rotation (PEFR) relates to posterolateral elbow joint instability, and is considered a possible requisite step in a simple posterior elbow joint dislocation. The aim of this study was to evaluate the capsuloligamentous restraint to PEFR. In all, 18 elbow joint specimens were examined in a joint analysis system developed for experimental elbow dislocation. Sequential cutting of capsule and ligaments followed by stability testing provided specific data relating to each capsuloligamentous structure. The primary stabilizers against PEFR in the extended elbow were the anterior capsule and the lateral collateral ligament complex (LCLC), whereas in the flexed elbow the anterior capsule did not have a stabilizing effect. In flexed joint positions, the LCLC seems to be the only immediate stabilizer against PEFR, and thereby against posterolateral instability and possibly against posterior dislocation. The medial collateral ligament did not have any immediate stabilizing effect, but it prevented the final step of the posterior dislocation.

  11. Ossification of the posterior atlantoaxial membrane associated with atlas hypoplasia

    PubMed Central

    Meng, Yichen; Zhou, Dongxiao; Gao, Rui; Ma, Jun; Wang, Ce; Zhou, Xuhui

    2016-01-01

    Abstract Rationale: Hypoplasia with an intact posterior arch of the atlas and ossification of the posterior atlantoaxial membrane (PAAM) are individually rare. Patient concerns: The patient presented with a 6-month history of progressive weakness and paresthesia of his lower extremities. Diagnoses: Cervical myelopathy resulting from atlas hypoplasia and ossification of the posterior atlantoaxial membrane. Interventions: Laminectomy of the atlas with duroplasty. Outcomes: Preoperative symptoms were alleviated. Lessons: In most reported cases, either atlas hypoplasia or ossification of the PAAM is responsible for patients’ myelopathy. The case illustrated here, to the best of our knowledge, is the first one with coexistent atlas hypoplasia and ossification of the PAAM. And laminectomy of the atlas with duroplasty provided satisfied outcome. PMID:27902623

  12. Language Disorders due to Posterior System Strokes - An Ignored Dysfunction

    PubMed Central

    ÖZTÜRK, Şerefnur; EGE, Fahrettin; EKMEKÇİ, Hakan

    2014-01-01

    The anterior system is primarily responsible for the clinical picture in a patient that presents with clinical aphasia. However, recent reports have shown that injuries to posterior structures, the cerebellum in particular, may have a role in language processing. Herein, we will look first at the linguistic role of the cerebellum in light of the literature, then of the thalamus and some described clinical syndromes, and finally, specific syndromes resulting from occipital lobe lesions, all of which are supported by the posterior vascular system. The human brain is such a complex organization that in addition to the thalamus and occipital cortex, we can see the involvement of the cerebellum in high cognitive functions. Posterior system strokes may lead to clinical findings of cognitive deficits, including neurolinguistic components. Determining these defects in stroke patients may precipitate changes in current management strategies. PMID:28360648

  13. [Segmental posterior spinal osteosynthesis using the Luque-Dove technic].

    PubMed

    Kerboul, B; Courtois, B

    1989-03-01

    The Hartshill frame is method for segmental osteosynthesis of the spine. It is attached at each vertebral level by sub-laminal metal wires. This frame therefore ensures immediate stability and avoids the need for a post-operative corset. It enables correction of frontal deformities (scoliosis) whilst retaining sagittal physiological curves (lumbar lordosis--dorsal kyphosis). It ensures the fixation of posterior spinal instability (destruction of posterior ligaments and bone tissue, spondylolisthesis, etc.). The Hartshill frame can thus be seen to be a posterior brace. It has been used in 92 patients, (53 lumbar disorders, 10 cases of scoliosis, 4 of kyphosis, 19 tumors, 6 fractures). Results are generally entirely satisfactory in the mid term apart from fractures (recurrence of initial displacement). Specific complications are of a neurological nature (cases of cutaneous hyperesthesia, one severe motor deficit) long-term problems with device and material are uncommon; rupture of sub-laminar wire 8 cases; secondary incurving of frame 1 case.

  14. Ganglion cyst of the posterior cruciate ligament in a child.

    PubMed

    Hameed, Shamsi Abdul; Sujir, Premjit; Naik, Monappa A; Rao, Sharath K

    2012-04-01

    Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children.

  15. Posterior Wall Gastric Leiomyoma: Endoscopic Tattooing Facilitates Laparoscopic Resection

    PubMed Central

    Mehta, Dhiren; Zelen, Johnathan; Fogler, Richard

    1998-01-01

    Objective: To demonstrate the application of tattooing for the intraoperative localization of posterior wall gastric leiomyoma during laparoscopic resection. The preoperative injection of Indian ink in the tumor-bearing area of the posterior gastric wall eliminates the need to perform anterior wall gastrostomy or intraoperative upper endoscopic tumor localization. Methods: A patient with posterior wall gastric leiomyoma was marked with Indian ink during preoperative upper endoscopy. The dye was visualized intraoperatively facilitating wedge resection of the tumor-bearing area with the Endo GIA. Results: The patient had an uneventful surgery and recovery. Complete excision of the tumor was accomplished. Conclusion: The preoperative endoscopic marking of gastric lesions, facilitates the intraoperative localization and resection of these lesions. PMID:9876718

  16. Structural Position of the Posterior Vagina and Pelvic Floor in Women with and without Posterior Vaginal Prolapse

    PubMed Central

    LEWICKY-GAUPP, Christina; YOUSUF, Aisha; LARSON, Kindra A; FENNER, Dee E; DeLANCEY, John OL

    2012-01-01

    Objective Compare pelvic structure location on MRI during maximal Valsalva among women with posterior prolapse and those with normal support. Methods and Materials Cases (n=37) had posterior vaginal wall (PVW) prolapse > +1cm. All underwent mid-sagittal, dynamic MRI. Structure locations (distal vagina, apex, perineal body, external anal sphincter) were determined. PVW length, levator and urogenital hiatus diameters, and prolapse diameter were measured. Results Cases had more caudal structures (p<0.001) and larger hiatus diameters (p<0.005); the posterior wall was longer, while the straight-line distance between the apex and distal vagina was shorter. In enteroceles, the apex was more ventrally displaced compared to rectoceles (p=0.003). Unlike apical descent (r=-0.3, p=0.1), PVW length and point Bp were correlated with MRI prolapse size (r=0.5, p=0.002; r=0.7, P<0.001, respectively). Conclusion At maximal Valsalva on MRI, structures are more caudal in women with posterior prolapse. The posterior vaginal wall is longer; this length strongly correlates with prolapse size. PMID:20452497

  17. Posterior clinoidectomy: dural tailoring technique and clinical application.

    PubMed

    Youssef, A Samy; van Loveren, Harry R

    2009-05-01

    The posterior clinoid process, a bony prominence at the superolateral aspect of the dorsum sellae, has a strategic importance in a transcavernous approach to basilar tip aneurysms. To further optimize this microsurgical technique during posterior clinoidectomy, we performed a cadaveric study of this regional anatomy, describe a technique called dural tailoring, and report initial results in the surgical treatment of upper basilar artery (BA) aneurysm. After 10 adult cadaver heads (silicone-injected) were prepared for dissection, a posterior clinoidectomy with dural tailoring was performed. The dura overlying the upper clivus was coagulated with bipolar electrocoagulation and incised. Stripping dura off the clivus and lateral reflection then exposed the ipsilateral posterior clinoid process and dorsum sellae, thus creating a dural flap. Posterior clinoidectomy with dural tailoring was then used in seven patients with upper BA aneurysms. Our stepwise modification of the posterior clinoidectomy with dural tailoring created a flap that afforded protection of the cavernous sinus and oculomotor nerve. During surgery, there were no recorded intraoperative injuries to neurovascular structures. One patient died postoperatively from morbidity related to severe-grade subarachnoid hemorrhage. Postoperative oculomotor nerve palsy occurred in 3 patients (43%). In all cases, the nerve was anatomically preserved and partial to complete recovery was recorded during the first postoperative year. This technique effectively provided exposure of retrosellar upper basilar aneurysms in seven patients (basilar tip 43% and superior cerebellar artery aneurysms 57%). Outcomes and safety are at least equivalent to or better than basilar aneurysm surgery performed without surgical adjuncts, presumably a less complex subset.

  18. Teaching of posterior composites in dental schools in Japan.

    PubMed

    Hayashi, M; Seow, L L; Lynch, C D; Wilson, N H F

    2009-04-01

    The teaching of posterior composites has undergone considerable refinement and development in western countries in recent years. However, little information exists on this teaching in other parts of the world. The aim of this paper is to investigate the teaching of posterior composites to undergraduate dental students in Japan. In late 2007/early 2008, a questionnaire seeking information on the teaching of posterior composites was distributed by email to the person responsible for teaching operative dentistry in each of the 29 dental schools having undergraduate dental degree programmes in Japan. Twenty-three completed responses were returned (response rate = 79%). While all 23 schools taught the placement of composite in occlusal cavities in premolars and molars, 7 schools did not teach the placement of two-surface occlusoproximal composites in premolars (n = 1) and molars (n = 6) and 14 schools and 15 schools do not teach placement of three surface occlusoproximal composites in premolars and molars, respectively. While composite at the time of the survey accounted for 45% of posterior direct restorations placed by students, it is anticipated that this proportion will increase to 59% in 5 years time. Variations were noted between schools in the teaching of principles of cavity design, techniques for restoring proximal contours and light-curing technologies; however, more consistency was observed in techniques used for protecting operatively exposed dentine than that observed in western countries. Despite variations between dental schools being noted in the teaching of certain techniques for posterior composites, the overall extent and content of teaching of posterior composites in Japan could be described as comparable, if not exceeding, than that observed in western countries.

  19. Posterior tibial vein aneurysm presenting as tarsal tunnel syndrome.

    PubMed

    Ayad, Micheal; Whisenhunt, Anumeha; Hong, EnYaw; Heller, Josh; Salvatore, Dawn; Abai, Babak; DiMuzio, Paul J

    2015-06-01

    Tarsal tunnel syndrome is a compressive neuropathy of the posterior tibial nerve within the tarsal tunnel. Its etiology varies, including space occupying lesions, trauma, inflammation, anatomic deformity, iatrogenic injury, and idiopathic and systemic causes. Herein, we describe a 46-year-old man who presented with left foot pain. Work up revealed a venous aneurysm impinging on the posterior tibial nerve. Following resection of the aneurysm and lysis of the nerve, his symptoms were alleviated. Review of the literature reveals an association between venous disease and tarsal tunnel syndrome; however, this report represents the first case of venous aneurysm causing symptomatic compression of the nerve.

  20. Posture and posterior crossbite in oral and nasal breathing children.

    PubMed

    Costa, Jecilene Rosana; Pereira, Silvia Regina Amorim; Pignatari, Shirley S N; Weckx, Luc Louis Maurice

    2010-01-01

    The most known etiologic factors of oral breathing may influence the craniofacial development leading to anatomical and functional alterations. A proper head and cervical spine posture allows a well functioning of the stomatognathic system structures and vice versa. This study was conducted to evaluate the prevalence of posterior crossbite in a group of oral breathing children (OB) and nasal (NB) and associate the type of bite with the head and cervical spine posture. It was concluded that most of the children, either oral or nasal breathers, did not present a crossbite and any kind of head posture and cervical spine can vary independently of a posterior crossbite.

  1. Posterior dislocation of the sternoclavicular joint: report of two cases.

    PubMed

    Labronici, Pedro José; Souza, Fabrício Cardoso de; Pires, Robinson Esteves Santos; Santos Filho, Fernando Claudino Dos; Gameiro, Vinicius Schott; Labronici, Gustavo José

    2016-01-01

    The authors report the cases of two young patients who had suffered a sporting accident with posterior traumatic dislocation of sternoclavicular joint. In one of the patients closed reduction was accomplished by keeping the limb in a sling. The second patient, after reduction was done, presented recurrence of the dislocation, thus requiring surgical treatment. It is important to observe the relevance of computed tomography to help diagnosing, as well as monitoring the reduction procedure. The objective of this study was to demonstrate two different types of treatment in a rare injury such as the posterior dislocation of sternoclavicular joint.

  2. Posterior shoulder dislocation while lifting weights: a missed diagnosis

    PubMed Central

    Cuffolo, Giulio; Coomber, Ross; Burtt, Simon; Gray, Jim

    2014-01-01

    Summary We present a case of a 24-year-old man who suffered acute shoulder pain and subsequent inability to move his arm while lifting weights in the bench-press position. He attended A&E where he was examined and X-rays were performed. He was diagnosed with presumed pectoralis major tendon rupture and was discharged to fracture clinic the following day with analgesia. On review in clinic he was found to have a posterior shoulder dislocation and was taken to theatre for relocation under anaesthesia. This case report examines the mechanism, investigations and management of posterior shoulder dislocation. PMID:24557475

  3. Spectral domain optical coherence tomography finding in posterior microphthalmos.

    PubMed

    Kumar, Mukesh; Das, Taraprasad; Kesarwani, Siddharth

    2012-11-01

    An eight-year-old boy presented with decreased vision in both eyes. At presentation, the visual acuity was 6/60 in both eyes with high plus spheres. Anterior segment examination was normal. Fundus examination and spectral domain optical coherence tomography were consistent with posterior microphthalmos and showed an elevated foveal contour and fold in the outer plexiform layer. External limiting membrane, photoreceptor and retinal pigment epithelium were not involved in the fold. To the best of our knowledge this is the first such case report with optical coherence tomography imaging of the retinal layer involved in a case of posterior microphthalmos.

  4. Recanalization of an occluded popliteal artery following posterior knee dislocation.

    PubMed

    Kirby, L; Abbas, J; Brophy, C

    1999-11-01

    Posterior knee dislocation results in popliteal artery injury in up to one-third of cases. Prompt recognition and treatment of arterial injury is essential for limb salvage. We report a case of complete occlusion of the popliteal artery following posterior knee dislocation treated with saphenous vein bypass without exclusion of the injured arterial segment. Follow-up duplex scanning demonstrated a patent vein graft and a patent ipsilateral popliteal artery. This report suggests that, in some instances, a traumatically occluded popliteal artery may recanalize, and that revascularization with a bypass graft may be the preferred method of repair, particularly in young patients.

  5. Bilateral epididymitis in a child with undiagnosed posterior urethral valves.

    PubMed

    Kwong, Justin; Lorenzo, Armando J; DeMaria, Jorge; Braga, Luis H P

    2013-07-01

    Posterior urethral valves are most commonly detected in the early neonatal period, the diagnosis often antenatally suspected from ultrasound findings. Nevertheless, some cases might go undetected and become manifest later in life with lower urinary tract symptoms. We describe the unusual case of a 5-year-old boy with a 2-month history of bladder distension, urinary dribbling, and epididymitis. Cystourethrography revealed posterior urethral valves with reflux into the seminal vesicles, vas deferens, and epididymis, bilaterally. A review of the published data is provided in the context of this unusual presentation pattern.

  6. Double triangular resection for a widely prolapsed posterior mitral leaflet†

    PubMed Central

    Sawazaki, Masaru; Tomari, Shiro; Tsunekawa, Tomohiro; Izawa, Naoto

    2013-01-01

    A wide and redundant prolapse of the posterior mitral leaflet in active infective endocarditis cannot be easily repaired. A sliding plasty can be attempted, but the range of annular plication is often too large. Chordal replacement is another option, but is prone to long-term degeneration because the redundant leaflet still exists. Here, we describe a simple resection technique that utilizes only two small triangular resections. The resections are sutured with no need to shorten the annulus. The leaflet tissue between the two triangular resections must be preserved to make an appropriately shaped posterior leaflet. PMID:23223672

  7. Recurrent Massive Epistaxis from an Anomalous Posterior Ethmoid Artery

    PubMed Central

    Mattioli, Francesco; Alberici, Maria Paola; Presutti, Livio

    2016-01-01

    A 50-year-old man, with no previous history of epistaxis, was hospitalized at our facility for left recurrent posterior epistaxis. The patient underwent surgical treatment three times and only the operator's experience and radiological support (cranial angiography) allowed us to control the epistaxis and stop the bleeding. The difficult bleeding management and control was attributed to an abnormal course of the left posterior ethmoidal artery. When bleeding seems to come from the roof of the nasal cavity, it is important to identify the ethmoid arteries always bearing in mind the possible existence of anomalous courses. PMID:28025632

  8. Posterior Trans-Dural Repair of Iatrogenic Spinal Cord Herniation after Resection of Ossification of Posterior Longitudinal Ligament

    PubMed Central

    Kim, Hong-Ki; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

    2016-01-01

    Iatrogenic spinal cord herniation is a rare complication following spinal surgery. We introduce a posterior trans-dural repair technique used in a case of thoracic spinal cord herniation through a ventral dural defect following resection of ossification of the posterior longitudinal ligament (OPLL) in the cervicothoracic spine. A 51-year-old female was suffering from paraplegia after laminectomy alone for cervicothoracic OPLL. Magnetic resonance imaging revealed a severely compressed spinal cord with pseudomeningocele identified postoperatively. Cerebrospinal fluid leak and iatrogenic spinal cord herniation persisted despite several operations with duroplasty and sealing agent. Finally, the problems were treated by repair of the ventral dural defect with posterior trans-dural duroplasty. Several months after surgery, the patient could walk independently. This surgical technique can be applied to treat ventral dural defect and spinal cord herniation. PMID:27114779

  9. 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.

  10. 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.

  11. Reverse slapper detonator

    DOEpatents

    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.

  12. Reversible fluctuation rectifier

    NASA Astrophysics Data System (ADS)

    Sokolov, I. M.

    1999-10-01

    The analysis of a Feynman's ratchet system [J. M. R. Parrondo and P. Español, Am. J. Phys. 64, 1125 (1996)] and of its electrical counterpart, a diode engine [I. M. Sokolov, Europhys. Lett. 44, 278 (1998)] has shown that ``fluctuation rectifiers'' consisting of a nonlinear element (ratchet, diode) and a linear element (vane, resistor) kept at different temperatures always show efficiency smaller than the Carnot value, thus indicating the irreversible mode of operation. We show that this irreversibility is not intrinsic for a system in simultaneous contact with two heat baths at different temperatures and that a fluctuation rectifier can work reversibly. This is illustrated by a model with two diodes switched in opposite directions, where the Carnot efficiency is achieved when backward resistivity of the diodes tends to infinity.

  13. 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.

  14. Reverse shoulder arthroplasty.

    PubMed

    Smithers, Christopher J; Young, Allan A; Walch, Gilles

    2011-12-01

    The reverse shoulder arthroplasty emerged as a potential solution for those patients who could not be managed effectively with a conventional total shoulder arthroplasty. Grammont revolutionized the design by medializing and distalizing the center of rotation and utilizing a large convex glenoid surface and concave humeral component with a neck-shaft angle of 155°. This design has been highly successful in cuff deficient shoulders, and indications continue to broaden. Many mid-term studies have improved upon the early encouraging results. Long-term studies are starting to emerge, demonstrating good survivorship, but progressive functional and radiographic deterioration continue to be concerning. Careful patient selection and attention to appropriate technique are required to reduce the current high rate of complications. New prosthesis designs are continuing to develop to address some of these limitations.

  15. 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.¬

  16. 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.

  17. 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.

  18. 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.

  19. Posterior Predictive Assessment of Item Response Theory Models

    ERIC Educational Resources Information Center

    Sinharay, Sandip; Johnson, Matthew S.; Stern, Hal S.

    2006-01-01

    Model checking in item response theory (IRT) is an underdeveloped area. There is no universally accepted tool for checking IRT models. The posterior predictive model-checking method is a popular Bayesian model-checking tool because it has intuitive appeal, is simple to apply, has a strong theoretical basis, and can provide graphical or numerical…

  20. 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

  1. Missed C1 posterior arch fracture: a case report

    PubMed Central

    Munro, Donald S

    1990-01-01

    A case of a C1 posterior arch fracture following a fall is presented. The need to perform a thorough history and examination, regardless of previous examination findings, is emphasized. This is especially true when there is a history of recent trauma. A brief discussion of the characteristics and management of C1 fractures follows. ImagesFigure 1Figure 2Figure 3

  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. Covering Your Posterior: Teaching Signaling Games Using Classroom Experiments

    ERIC Educational Resources Information Center

    Turocy, Theodore L.

    2009-01-01

    The author describes a protocol for classroom experiments for courses that introduce undergraduates to signaling games. Signaling games are conceptually difficult because, when analyzing the game, students are not naturally inclined to think in probabilistic, Bayesian terms. The experimental design explicitly presents the posterior frequencies of…

  4. Atrial natriuretic factor-like activity in rat posterior pituitary

    SciTech Connect

    Gutkowska, J.; Debinski, W.; Racz, K.; Thibault, G.; Garcia, R.; Kuchel, O.; Genest, J.; Cantin, M.

    1986-03-05

    The presence of a biologically active peptide: Atrial Natriuretic Factor (ANF) has been demonstrated in rat and human circulation and ANF is considered now as a new hormone. ANF may be involved in body fluid regulation. A very sensitive radioimmunoassay for rat ANF allowed the authors to search for immunoreactive ANF (IR-ANF) in rat posterior pituitary. Serial dilutions of homogenates of rat posterior pituitary showed a good parallelism with a reference curve in a radioimmunoassay system. The IR-ANF was extracted from rat posterior pituitary homogenates by activated Vycor glass beads. The lyophilized extract was purified by HPLC on C/sub 18/ ..mu.. Bondapak column. The HPLC yielded two IR-ANF peaks. Both isolated ANF-like material showed biological activity. The IR-ANF eluted with 33% acetonitrile, inhibited ACTH-stimulated aldosterone secretion with a similar potency as synthetic (Arg 101 - Tyr 126) ANF (0.7 x 10/sup -10/M). A much less potent ANF-like material was found in the second peak eluted with 36% acetonitrile. They conclude that ANF-like material is present in rat posterior pituitary and this suggest a possible role in ANF on AVP secretion directly in situ.

  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.

  6. The posterior meniscofemoral ligament: morphologic study and anatomic classification.

    PubMed

    Han, Seung-Ho; Kim, Deog-Im; Choi, Seung-Gyu; Lee, Jun-Hee; Kim, Yi-Suk

    2012-07-01

    The meniscofemoral ligaments (MFLs) run from the medial femoral condyle to the posterior horn of the lateral meniscus and consist of anterior MFL (aMFL) and/or posterior MFL (pMFL) components according to whether it passes anterior or posterior to the posterior cruciate ligament (PCL). The purpose of this study was to analyze the incidence and morphologic features of the MFLs in Koreans and formulate an anatomic classification system of MFLs to aid the detailed interpretation of medical imaging or biomechanical data. One hundred knees from 52 cadavers were studied. Eighty-seven knees had pMFLs, whereas an aMFL was only found in one knee from a male cadaver. The pMFLs and PCLs were longer in males than in females (P < 0.05). The most common type of MFL was the high crossing of a typical pMFL against the PCL in both genders. Regarding other types, the incidence of absent pMFLs was higher in males than in females and the oblique bundle of the PCL was easily confused with the pMFL in several cases in both genders. These results provide the basis for the classification system of the MFL and will contribute to better outcomes for evaluating the MFL and PCL when using medical imaging such as arthro-CT scan or MRI through a better understanding of the anatomy of the MFL and PCL.

  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. Roseomonas spinal epidural abscess complicating instrumented posterior lumbar interbody fusion.

    PubMed

    Maraki, Sofia; Bantouna, Vasiliki; Lianoudakis, Efstratios; Stavrakakis, Ioannis; Scoulica, Efstathia

    2013-07-01

    The first case of a spinal epidural abscess caused by Roseomonas mucosa following instrumented posterior lumbar fusion is presented. Although rare, because of its highly resistant profile, Roseomonas species should be included in the differential diagnosis of epidural abscesses in both immunocompromised and immunocompetent hosts.

  9. Distinguishing torpedo maculopathy from similar lesions of the posterior segment.

    PubMed

    Villegas, Victor M; Schwartz, Stephen G; Flynn, Harry W; Capó, Hilda; Berrocal, Audina M; Murray, Timothy G; Harbour, J William

    2014-01-01

    Torpedo maculopathy is a congenital solitary, oval-shaped lesion typically located temporal to the center of the macula. Congenital hypertrophy of the retinal pigment epithelium (RPE), RPE lesions of Gardner syndrome, and other lesions can present with similar characteristics. Because of its unique clinical and imaging features, torpedo maculopathy generally can be differentiated from other posterior segment lesions.

  10. Posterior Predictive Model Checking for Multidimensionality in Item Response Theory

    ERIC Educational Resources Information Center

    Levy, Roy; Mislevy, Robert J.; Sinharay, Sandip

    2009-01-01

    If data exhibit multidimensionality, key conditional independence assumptions of unidimensional models do not hold. The current work pursues posterior predictive model checking, a flexible family of model-checking procedures, as a tool for criticizing models due to unaccounted for dimensions in the context of item response theory. Factors…

  11. 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

  12. Trypan blue-assisted posterior capsulorhexis in pediatric cataract surgery

    PubMed Central

    Lotfy, Ayman; Abdelrahman, Ayman

    2017-01-01

    Purpose To evaluate the safety and efficacy of staining the posterior capsule with trypan blue during capsulorhexis in pediatric cataract surgery. Patients and methods This was a prospective randomized comparative study carried out at Alpha Vision Center, Zagazig, Egypt. This study included 2 groups of children with pediatric cataract randomly allocated to undergo irrigation and aspiration. In the trypan group, which included 11 eyes, trypan blue was used to stain the posterior capsule during posterior capsulorhexis. In the control group, which included 10 eyes, no staining was performed. All surgeries were performed by the same surgeon. The 2 groups were compared for criteria such as completion of capsulorhexis, disruption of vitreous face and in-the-bag intraocular lens implantation. Results This study included 21 eyes of 16 patients (age range: 6 months–4 years). A statistically significant difference was observed for the following parameters between the 2 groups: capsulorhexis completion (P=0.04), vitreous face disruption (P=0.01) and in-the-bag intraocular lens implantation (P=0.022). Conclusion This study suggests that staining of the posterior capsule during capsulorhexis in pediatric cataract operation gives better results than capsulorhexis without staining. The stain changes the capsule texture making capsulorhexis easier with fewer complications. PMID:28182152

  13. Tibialis posterior tendon rupture: a cause of rheumatoid flat foot.

    PubMed

    Downey, D J; Simkin, P A; Mack, L A; Richardson, M L; Kilcoyne, R F; Hansen, S T

    1988-03-01

    Flat foot, a major cause of foot pain and disability, may result from rupture of the tibialis posterior tendon. We describe 2 patients with rheumatoid arthritis who developed flat feet secondary to surgically confirmed tendon rupture, and we discuss the anatomy and diagnosis of this condition. In the second patient, we also present the results of tendon imaging with both magnetic resonance and ultrasound.

  14. Accuracy of Posterior Subtalar Joint Injection Without Fluoroscopy

    PubMed Central

    Kirk, Kevin L.; Campbell, John T.; Guyton, Gregory P.

    2008-01-01

    Injection into the posterior subtalar joint has not been validated for accuracy using radiographic end points. We asked whether needle placement into a normal posterior subtalar joint could be performed accurately and selectively by experienced surgeons without fluoroscopic guidance. Three fellowship-trained orthopaedic foot and ankle surgeons each injected the posterior subtalar joint of 20 cadaveric specimens using an anterolateral approach. Fluoroscopic images were obtained by an independent investigator and blinded. A separate fellowship-trained foot and ankle surgeon interpreted the images. Of 60 injections, 58 were accurate and two were extraarticular based on interpretation by an independent foot and ankle surgeon. Extravasation into the ankle occurred in 14 samples and into the peroneal sheath in two samples. Experienced surgeons can place intraarticular injections into a radiographically normal posterior subtalar joint without fluoroscopy with a high degree of accuracy. However, extravasation into the ankle or peroneal tendon sheath occurred in an unpredictable fashion, suggesting selectivity of injection placement is relatively limited without the use of fluoroscopy. Fluoroscopy may not be necessary for injections used solely for therapeutic purposes. However, if the injection is intended for diagnostic purposes or to assist in surgical decision-making or if the joint is abnormal, we recommend fluoroscopy to ensure the subtalar joint is the only anatomic structure impacted by the injection. PMID:18404293

  15. Posterior crossbite and temporomandibular disorders (TMDs): need for orthodontic treatment?

    PubMed

    Thilander, Birgit; Bjerklin, Krister

    2012-12-01

    The aim of this work was to update the bibliography regarding the concept of 'temporomandibular disorder (TMD)' and 'posterior crossbite' and try to find out if there is any association between some special signs/symptoms of TMD and type of posterior crossbite. A literature search from 1970 to 2009, due to specified criterion, resulted in 14 publications that were found to be relevant for the present systematic review. An association between TMD and posterior crossbite (Yes-group) was reported as often as absence of such a relationship (No-group). The samples in the two groups showed similarities as well as differences with respect to number, gender, and age. Most articles reported only on 'presence' or 'absence' of crossbite and only few on type of crossbite opposite to a thorough account of clinical signs and symptoms of TMD. This review seems, however, to state that a functional posterior crossbite (mandibular guidance with midline deviation) is associated with headache, temporomandibular joint and muscular pain, and clicking. As evident from the discussion, such type needs orthodontic treatment to rehabilitate the asymmetric muscular activity between the crossbite and non-crossbite sides and the changed condyle/temporal relationship caused by mandibular deviation. Whether this treatment also will avoid future TMD problems can be answered only after clinical follow-up studies have been performed.

  16. Magnetic reversals and mass extinctions

    NASA Technical Reports Server (NTRS)

    Raup, D. M.

    1985-01-01

    The results of a study of reversals of the earth's magnetic field over the past 165 Myr are presented. A stationary periodicity of 30 Myr emerges which predicts pulses of increased reversal activity centered at 10, 40, 70, . . . Myr before the present. The correlation between the reversal intensity and biological extinctions is examined, and a nontrivial discrepancy is found between the magnetic and extinction periodicity.

  17. Anterior and posterior corneal stroma elasticity assessed using nanoindentation

    PubMed Central

    Dias, Janice; Ziebarth, Noël M.

    2013-01-01

    Corneal biomechanics is an essential parameter for developing diagnostic and treatment methods of corneal-related diseases. It is widely accepted that corneal mechanical strength stems from the stroma's collagenous composition. However, more comprehensive insight into the mechanical properties within the stroma is needed to improve current corneal diagnostic and treatment techniques. The purpose of this study was to perform elasticity characterization of anterior and posterior stromal regions of human corneas using atomic force microscopy (AFM). Nine pairs of human whole globes were placed in 20% Dextran solution, cornea side down, to restore the corneal thickness to physiological levels (400-600μm). The epithelium and Bowman's membrane were removed from all eyes. Anterior stromal AFM elasticity testing was then performed on left (OS) eyes. Additional stroma was removed from right (OD) eyes to allow posterior stromal measurements at a depth of 50% of the original thickness. All experiments were performed with corneas submerged in 15% Dextran to maintain corneal hydration. The results of the study showed that the Young's modulus of elasticity of the anterior stroma (average: 281 ± 214kPa; range: 59-764kPa) was significantly higher than that of the posterior stroma (average: 89.5 ± 46.1kPa; range: 29-179kPa) (p=0.014). In addition, a linear relationship was found between the posterior stromal elasticity and anterior stromal elasticity (p=0.0428). On average, the elasticity of the posterior stroma is 39.3% of the anterior stroma. In summary, there appears to be an elasticity gradient within the corneal stroma, which should be considered in the design and development of corneal diagnostic and treatment methods to enhance efficacy. PMID:23800511

  18. Morphofunctional Compensation of Masseter Muscles in Unilateral Posterior Crossbite Patients

    PubMed Central

    Cutroneo, G.; Vermiglio, G.; Centofanti, A.; Rizzo, G.; Runci, M.; Favaloro, A.; Piancino, M.G.; Bracco, P.; Ramieri, G.; Bianchi, F.; Speciale, F.; Arco, A.; Trimarchi, F.

    2016-01-01

    Unilateral posterior crossbite is a widespread, asymmetric malocclusion characterized by an inverse relationship of the upper and lower buccal dental cusps, in the molar and premolar regions, on one side only of the dental arch. Patients with unilateral posterior crossbite exhibit an altered chewing cycles and the crossbite side masseter results to be less active with respect to the contralateral one. Few studies about morphological features of masticatory muscle in malocclusion disorders exist and most of these have been performed on animal models. The aim of the present study was to evaluate morphological and protein expression characteristics of masseter muscles in patients affected by unilateral posterior crossbite, by histological and immunofluorescence techniques. We have used antibody against PAX-7, marker of satellite cells, and against α-, β-, γ-, δ-, ε- and ζ-sarcoglycans which are transmembrane glycoproteins involved in sarcolemma stabilization. By statistical analysis we have evaluated differences in amount of myonucley between contralateral and ipsilateral side. Results have shown: i) altered fibers morphology and atrophy of ipsilateral muscle if compared to the contralateral one; ii) higher number of myonuclei and PAX-7 positive cells in contralateral side than ipsilateral one; iii) higher pattern of fluorescence for all tested sarcoglycans in contralateral side than ipsilateral one. Results show that in unilateral posterior crossbite hypertrophic response of contralateral masseter and atrophic events in ipsilateral masseter take place; by that, in unilateral posterior crossbite malocclusion masticatory muscles modify their morphology depending on the function. That could be relevant in understanding and healing of malocclusion disorders; in fact, the altered balance about structure and function between ipsilateral and contralateral muscles could, long-term, lead and/ or worsen skeletal asymmetries. PMID:27349311

  19. Posterior Eye Shape Measurement With Retinal OCT Compared to MRI

    PubMed Central

    Kuo, Anthony N.; Verkicharla, Pavan K.; McNabb, Ryan P.; Cheung, Carol Y.; Hilal, Saima; Farsiu, Sina; Chen, Christopher; Wong, Tien Y.; Ikram, M. Kamran; Cheng, Ching Y.; Young, Terri L.; Saw, Seang M.; Izatt, Joseph A.

    2016-01-01

    Purpose Posterior eye shape assessment by magnetic resonance imaging (MRI) is used to study myopia. We tested the hypothesis that optical coherence tomography (OCT), as an alternative, could measure posterior eye shape similarly to MRI. Methods Macular spectral-domain OCT and brain MRI images previously acquired as part of the Singapore Epidemiology of Eye Diseases study were analyzed. The right eye in the MRI and OCT images was automatically segmented. Optical coherence tomography segmentations were corrected for optical and display distortions requiring biometry data. The segmentations were fitted to spheres and ellipsoids to obtain the posterior eye radius of curvature (Rc) and asphericity (Qxz). The differences in Rc and Qxz measured by MRI and OCT were tested using paired t-tests. Categorical assignments of prolateness or oblateness using Qxz were compared. Results Fifty-two subjects (67.8 ± 5.6 years old) with spherical equivalent refraction from +0.50 to −5.38 were included. The mean paired difference between MRI and original OCT posterior eye Rc was 24.03 ± 46.49 mm (P = 0.0005). For corrected OCT images, the difference in Rc decreased to −0.23 ± 2.47 mm (P = 0.51). The difference between MRI and OCT asphericity, Qxz, was −0.052 ± 0.343 (P = 0.28). However, categorical agreement was only moderate (κ = 0.50). Conclusions Distortion-corrected OCT measurements of Rc and Qxz were not statistically significantly different from MRI, although the moderate categorical agreement suggests that individual differences remained. This study provides evidence that with distortion correction, noninvasive office-based OCT could potentially be used instead of MRI for the study of posterior eye shape. PMID:27409473

  20. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  1. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  2. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  3. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  4. 49 CFR 230.89 - Reverse gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  5. Reversible MRI findings in a case of acute intermittent porphyria with a novel mutation in the porphobilinogen deaminase gene.

    PubMed

    Yang, Jing; Yang, Hang; Chen, Qianlong; Hua, Baolai; Zhu, Tienan; Zhao, Yongqiang; Yu, Xuezhong; Zhu, Huadong; Zhou, Zhou

    2017-03-01

    Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by a partial deficiency of porphobilinogen deaminase (PBGD), the third enzyme in the of heme biosynthetic pathway. It can affect the autonomic, peripheral, and central nervous system. Posterior reversible encephalopathy syndrome is a clinicoradiological entity characterized by headache, seizures, altered consciousness, and visual disorder associated with potentially reversible neuroradiological abnormalities predominantly in the parieto-occipital lobes. Establishing accurate diagnoses of the patient and asymptomatic family members with AIP involves identifying the PBGD enzyme mutations directly. In this study, we report a 28-year-old woman with acute intermittent porphyria who presented with radiological manifestations suggestive of posterior reversible encephalopathy syndrome, she had a novel PBGD frame shift mutation, base 875 and 876 have been deleted resulting in glutamine to a stop codon (Gln292fs), in a Chinese family.

  6. Posterior Capsular Opacification in Preschool- and School-Age Patients after Pediatric Cataract Surgery without Posterior Capsulotomy

    PubMed Central

    Batur, Muhammed; Gül, Adem; Seven, Erbil; Can, Ertuğrul; Yaşar, Tekin

    2016-01-01

    Objectives: We aimed to evaluate the development of posterior capsular opacification (PCO) in preschool- and school-age children with cataract who underwent cataract surgery without posterior capsulotomy and anterior vitrectomy. Materials and Methods: The records of 30 eyes of 21 patients who underwent pediatric cataract surgery and intraocular lens (IOL) implantation were retrospectively reviewed. Patients’ age, PCO status and duration, need for neodymium-doped yttrium aluminium garnet (Nd:YAG) laser treatment based on coverage of visual axis, and follow-up period were recorded. Results: The mean age of the patients was 7.6±2.83 (4-12) years. Unilateral cataract surgery and IOL implantation were performed in 12 patients (57.14%) and bilateral cataract surgery and IOL implantation were performed in nine patients (42.86%). Average follow-up time was 17.7±22.67 (3-83) months. PCO developed in 21 eyes (70%) and covered the visual axis in 15 eyes (50%), which therefore required Nd:YAG laser posterior capsulotomy. The mean duration of postoperative PCO development was 8.91±18.7 months (1 week-71 months). Conclusion: We believe that with adequately experienced surgeons, performing both cataract surgery and posterior capsulotomy with anterior vitrectomy in the same session is appropriate for selected preschool- and school-age children with cataract. PMID:28058161

  7. 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.

  8. 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.

  9. 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.

  10. Reversibility in nucleocytoplasmic transport

    PubMed Central

    Kopito, Ronen Benjamine; Elbaum, Michael

    2007-01-01

    Nucleocytoplasmic exchange of proteins and RNAs is mediated by receptors that usher their cargo through the nuclear pores. Peptide localization signals on each cargo determine the receptors with which it will interact. Those interactions are normally regulated by the small GTPase Ran. Hydrolysis of GTP provides the chemical energy required to create a bona fide thermodynamic pump that selectively and directionally accumulates its substrates across the nuclear envelope. A common perception is that cargo delivery is irreversible, e.g., a protein imported to the nucleus does not return to the cytoplasm except perhaps via a specific export receptor. Quantitative measurements using cell-free nuclei reconstituted in Xenopus egg extract show that nuclear accumulation follows first-order kinetics and reaches steady state at a level that follows a Michaelis–Menten function of the cytoplasmic cargo concentration. This saturation suggests that receptor-mediated translocation across the nuclear pore occurs bidirectionally. The reversibility of accumulation was demonstrated directly by exchange of the cytosolic medium and by fluorescence recovery after photobleaching. Based on our results, we offer a simple biophysical model that predicts the observed behavior. A far-reaching consequence is that the nuclear localization signal dictates the fate of a protein population rather than that of the individual molecules that bear it, which remain free to shuttle back and forth. This implies an open communication between the nucleus and cytoplasm and a ubiquitous mechanism for signaling in both directions. PMID:17646647

  11. Reverse genetics of avian metapneumoviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An overview of avian metapneumovirus (aMPV) infection in turkeys and development of a reverse genetics system for aMPV subgroup C (aMPV-C) virus will be presented. By using reverse genetics technology, we generated recombinant aMPV-C viruses containing a different length of glycoprotein (G) gene or...

  12. Play: The Reversal Theory Perspective.

    ERIC Educational Resources Information Center

    Kerr, J. H.

    The intention of this theoretical paper is to present a reversal theory interpretation of play phenomena. Reversal theory, a developing theory in psychology, concerns the complex relationship between experience and motivation. One of the central charactieristics of the theory is that it attempts to understand why so much of human behavior is…

  13. 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…

  14. 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…

  15. Posterior arch C-1 screw technique: a cadaveric comparison study.

    PubMed

    Moisi, Marc; Fisahn, Christian; Tkachenko, Lara; Jeyamohan, Shiveindra; Reintjes, Stephen; Grunert, Peter; Norvell, Daniel C; Tubbs, R Shane; Page, Jeni; Newell, David W; Nora, Peter; Oskouian, Rod J; Chapman, Jens

    2017-03-17

    OBJECTIVE Posterior atlantoaxial stabilization and fusion using C-1 lateral mass screw fixation has become commonly used in the treatment of instability and for reconstructive indications since its introduction by Goel and Laheri in 1994 and modification by Harms in 2001. Placement of such lateral mass screws can be challenging because of the proximity to the spinal cord, vertebral artery, an extensive venous plexus, and the C-2 nerve root, which overlies the designated starting point on the posterior center of the lateral mass. An alternative posterior access point starting on the posterior arch of C-1 could provide a C-2 nerve root-sparing starting point for screw placement, with the potential benefit of greater directional control and simpler trajectory. The authors present a cadaveric study comparing an alternative strategy (i.e., a C-1 screw with a posterior arch starting point) to the conventional strategy (i.e., using the lower lateral mass entry site), specifically assessing the safety of screw placement to preserve the C-2 nerve root. METHODS Five US-trained spine fellows instrumented 17 fresh human cadaveric heads using the Goel/Harms C-1 lateral mass (GHLM) technique on the left and the posterior arch lateral mass (PALM) technique on the right, under fluoroscopic guidance. After screw placement, a CT scan was obtained on each specimen to assess for radiographic screw placement accuracy. Four faculty spine surgeons, blinded to the surgeon who instrumented the cadaver, independently graded the quality of screw placement using a modified Upendra classification. RESULTS Of the 17 specimens, the C-2 nerve root was anatomically impinged in 13 (76.5%) of the specimens. The GHLM technique was graded Type 1 or 2, which is considered "acceptable," in 12 specimens (70.6%), and graded Type 3 or 4 ("unacceptable") in 5 specimens (29.4%). In contrast, the PALM technique had 17 (100%) of 17 graded Type 1 or 2 (p = 0.015). There were no vertebral artery injuries found

  16. 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.

  17. The posterior neural plate in axolotl gives rise to neural tube or turns anteriorly to form somites of the tail and posterior trunk.

    PubMed

    Taniguchi, Yuka; Kurth, Thomas; Weiche, Susanne; Reichelt, Saskia; Tazaki, Akira; Perike, Srikanth; Kappert, Verena; Epperlein, Hans-Henning

    2017-02-15

    Classical grafting experiments in the Mexican axolotl had shown that the posterior neural plate of the neurula is no specified neuroectoderm but gives rise to somites of the tail and posterior trunk. The bipotentiality of this region with neuromesodermal progenitor cell populations was revealed more recently also in zebrafish, chick, and mouse. We reinvestigated the potency of the posterior plate in axolotl using grafts from transgenic embryos, immunohistochemistry, and in situ hybridization. The posterior plate is brachyury-positive except for its more anterior parts which express sox2. Between anterior and posterior regions of the posterior plate a small domain with sox2+ and bra+ cells exists. Lineage analysis of grafted GFP-labeled posterior plate tissue revealed that posterior GFP+ cells move from dorsal to ventral, form the posterior wall, turn anterior bilaterally, and join the gastrulated paraxial presomitic mesoderm. More anterior sox2+/GFP+ cells, however, are integrated into the developing spinal cord. Tail notochord is formed from axial mesoderm involuted already during gastrulation. Thus the posterior neural plate is a postgastrula source of paraxial mesoderm, which performs an anterior turn, a novel morphogenetic movement. More anterior plate cells, in contrast, do not turn anteriorly but become specified to form tail spinal cord.

  18. 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.

  19. 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.

  20. Transoral decompression and posterior stabilisation in Morquio's disease.

    PubMed Central

    Ashraf, J; Crockard, H A; Ransford, A O; Stevens, J M

    1991-01-01

    A 3.5 year old boy with Morquio's disease was referred with a persisting left hemiparesis four months after a fall and was found to have craniocervical junction compression due to atlantoaxial subluxation and significant anterior soft tissue compression. Transient unconsciousness at the time of the fall was probably due to medullary concussion as a result of hyperextension, not a head injury. Spinal cord compression due to atlantoaxial subluxation at the craniovertebral junction is a major cause of disability and death in these patients. Once cervical myelopathy appears, early posterior occipitocervical fusion has been advocated in order to arrest the progression of neurological disability and this is successful in most cases. This conventional approach was considered unsafe because of the significant anterior compression. A combined anterior transoral decompression with posterior fusion to deal with this particularly difficult problem is described. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1755646

  1. [Macular threshold after ECCE and posterior chamber IOL implantation].

    PubMed

    Baltatzis, S; Georgopoulos, G; Andreanos, D

    1989-01-01

    In the present paper, the macular threshold after ECCE and posterior chamber intraocular lens implantation, was studied in an effort to determine the time period needed for full postoperative recovery of macular function. We evaluated 22 eyes in 20 patients who underwent extracapsular cataract extraction and posterior chamber IOL implantation. There were 12 men and 8 women between the ages of 40 and 62 years with mean age of 53 years. Postoperative visual field testing was performed within the central 4 degrees with an automated static perimeter (Humphrey Visual Field Analyser), using a macular threshold test pattern. It has been established that central retinal sensitivity in pseudophakia shows a postoperative decrease and consequently recovers to almost normal levels within one month. The exact cause of this reduction remains under discussion and further control mainly with fluorescein angiography is necessary.

  2. Clinical Characteristics of Posterior and Lateral Semicircular Canal Dehiscence

    PubMed Central

    Spasic, Marko; Trang, Andy; Chung, Lawrance K.; Ung, Nolan; Thill, Kimberly; Zarinkhou, Golmah; Gopen, Quinton S.; Yang, Isaac

    2015-01-01

    The objective of this study was to evaluate the characteristic symptoms of and treatments for lateral semicircular canal dehiscence (LSCD) and posterior semicircular canal dehiscence (PSCD) and its proposed mechanism. A dehiscence acquired in any of the semicircular canals may evoke various auditory symptoms (autophony and inner ear conductive hearing loss) or vestibular symptoms (vertigo, the Tullio phenomenon, and Hennebert sign) by creating a “third mobile window” in the bone that enables aberrant communication between the inner ear and nearby structures. A PubMed search was performed using the keywords lateral, posterior, and semicircular canal dehiscence to identify all relevant cases. Our data suggest that PSCD, although clinically rare, is most likely associated with a high-riding jugular bulb and fibrous dysplasia. Patients may experience auditory manifestations that range from mild conductive to extensive sensorineural hearing loss. LSCD is usually associated with chronic otitis media with cholesteatoma. PMID:26682120

  3. Posterior polymorphous dystrophy of the cornea. An ultrastructural study.

    PubMed

    de Felice, G P; Braidotti, P; Viale, G; Bergamini, F; Vinciguerra, P

    1985-01-01

    A corneal button excised from a 2-month-old infant with congenital posterior polymorphous dystrophy of the cornea, a rare disease affecting Descemet's membrane and endothelium, was examined by electron microscopy. We observed irregularly arranged, sometimes multilayered cells with marked epithelial features, lining the posterior surface of the cornea in place of the endothelium, and Descemet's membrane with focal alterations sometimes involving all of its layers. We interpreted these abnormal cells as epithelial-like cells. As these findings were in a very young patient, which is unusual, we concluded that the onset of the disease may take place in the early period of intrauterine life, corresponding to the beginning of Descemet's membrane production.

  4. 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

  5. Posterior left atrial wall hematoma mimicking cystic intracavitary atrial mass.

    PubMed

    Bahnacy, Yasser; Suresh, Cheriyil; Dawoud, Hamed; Zubaid, Mohammad

    2010-10-01

    Atrial myxoma is the most common benign primary tumor of the heart most commonly in the left atrium (LA). Cystic or cavitated intracardiac masses are rare. We report the case of a 43-year-old male patient admitted with chest infection, hemoptysis, and severe respiratory distress, who had to be ventilated. Chest computed tomography showed bilateral lung consolidation with large mass occupying the region of the LA. Transthoracic echocardiography and transesophageal echocardiography showed a large intracavitary left atrial cystic mobile mass. Open-heart surgical exploration did not show any mass inside the LA. A posterior left atrial wall hematoma was found and evacuated. Biopsies confirmed the presence of blood clots. Posterior left atrial wall hematoma may appear as left atrial intracavitary cystic mass and should be included in the differential diagnosis of cystic left atrial mass.

  6. [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.

  7. Downregulation of the posterior medial frontal cortex prevents social conformity.

    PubMed

    Klucharev, Vasily; Munneke, Moniek A M; Smidts, Ale; Fernández, Guillén

    2011-08-17

    We often change our behavior to conform to real or imagined group pressure. Social influence on our behavior has been extensively studied in social psychology, but its neural mechanisms have remained largely unknown. Here we demonstrate that the transient downregulation of the posterior medial frontal cortex by theta-burst transcranial magnetic stimulation reduces conformity, as indicated by reduced conformal adjustments in line with group opinion. Both the extent and probability of conformal behavioral adjustments decreased significantly relative to a sham and a control stimulation over another brain area. The posterior part of the medial frontal cortex has previously been implicated in behavioral and attitudinal adjustments. Here, we provide the first interventional evidence of its critical role in social influence on human behavior.

  8. 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

  9. Posterior sternoclavicular dislocations--a diagnosis easily missed.

    PubMed Central

    Thomas, D. P.; Davies, A.; Hoddinott, H. C.

    1999-01-01

    Posterior dislocation of the sternoclavicular joint is a relatively rare injury and can be difficult to diagnose acutely. We report 3 cases of posterior dislocation of the sternoclavicular joint who presented to the Accident & Emergency Department within a 3 month period. All 3 patients had sustained a significant injury to the shoulder region and complained of pain around the medial clavicle. Two patients had also complained of dysphagia following the injury. Plain X-rays of the shoulder and chest were reported as normal by junior and senior medical staff. The diagnosis was delayed until CT scans were performed, and once this was established, open reduction and stabilisation was performed. Images Figure 1 Figure 2 Figure 3 p204-a PMID:10364956

  10. Absence of Posterior Triangle: Clinical and Embryological Perspective

    PubMed Central

    Singh, Shikha; Loh, Hitendra Kumar; Mehta, Vandana; Suri, Rajesh Kumar

    2017-01-01

    Sternocleidomastoid (SCM) and Trapezius (TM) muscle present in the cervical region serves as an important landmark in forming boundaries of posterior triangle of neck. This case reports a continuous muscle sheet obscuring the left posterior triangle in the neck of a 60-year-old Indian male cadaver. An unfamiliar oval gap was observed in its posterosuperior portion. Description of such a variant in anatomical literature is rare and is scarcely reported. An attempt has been made to portray its embryological and phylogenetic basis. In addition authors have endeavoured to discuss its clinical implications. Awareness of such anatomical variations is relevant for the operating surgeons in their endeavour to perform various reconstruction surgeries of head and neck, radiologists while concluding various levels in Computed Tomography (CT) and Magnetic Resonance Images (MRI) of the region and to the anaesthetists in their search for nerves and vessels while attempting various anaesthetic procedures. PMID:28384846

  11. Lumbo-costo-vertebral syndrome with posterior spinal dysraphism.

    PubMed

    Kumar, G Samson Sujit; Kulkarni, Vaijayantee; Haran, R P

    2005-09-01

    Lumbo-costo-vertebral syndrome, which includes abnormalities of the vertebral bodies, ribs and trunk musculature, is very rare and only few cases have been reported. We report a case of 18-month-old female child with absent ribs, hemivertebrae, superior lumbar hernia (features of lumbo-costo-vertebral syndrome) and posterior spinal dysraphism, which to our knowledge is the first case in the English literature with such a combination of defects. Embryology and management of the case is discussed.

  12. Detachments of the retinal pigment epithelium at the posterior pole.

    PubMed

    Noble, K G; Levitzky, M J; Carr, R E

    1976-08-01

    Multiple vitelliform cysts of the retina, a disorder of unknown cause in which there are multiple detachments of the retinal pigment epithelium at the posterior pole, occurred in five patients. In four patients all lesions were located outside the parafoveal area while one patient showed bilateral foveal elevations associated with more eccentric detachments. Several patients showed slow resolution of some of the detachments with mild disturbances of the pigment epithelium.

  13. Stenting for a symptomatic posterior cerebral artery stenosis.

    PubMed

    Xu, Gelin; Zheng, Ling; Zhou, Zhiming; Liu, Xinfeng

    2009-05-01

    Evolvement of endovascular devices and increase of operator expertise have made angioplasty and stenting in intracranial vessels technically possible. Stenting has been reported in treating stenosis in middle and anterior cerebral arteries with favorable outcomes. However, the feasibility of stenting for stenosis in posterior cerebral artery (PCA) has not been established. We report a patient with progressive focal cerebral ischemic symptoms, which were arrested after reconstruction of the associated PCA stenosis with stenting.

  14. Classical caesarean section through the posterior uterine wall.

    PubMed

    Bolaji, I I; Rafla, N M; Mylotte, M J

    1992-02-01

    We report a case of myomectomy and classical caesarean section through the posterior uterine wall necessitated by 180 degrees dextro-rotation of a gravid uterus with large fibroids. The non-specific clinical course and rarity of pathological torsion of the gravid uterus makes the preoperative diagnosis difficult. Ultrasound recognition antenatally of a fibroid changing its position should help with the prediction preoperatively of uterine rotation.

  15. Cadherin-mediated adhesion regulates posterior body formation

    PubMed Central

    Harrington, Michael J; Hong, Elim; Fasanmi, Oluwafoyinsa; Brewster, Rachel

    2007-01-01

    Background The anterior-posterior axis of the vertebrate embryo undergoes a dramatic elongation during early development. Convergence and extension of the mesoderm, occurring during gastrulation, initiates the narrowing and lengthening of the embryo. However the lengthening of the axis continues during post-gastrula stages in the tailbud region, and is thought to involve convergent extension movements as well as other cell behaviors specific to posterior regions. Results We demonstrate here, using a semi-dominant N-cadherin allele, that members of the classical cadherin subfamily of cell-cell adhesion molecules are required for tailbud elongation in the zebrafish. In vivo imaging of cell behaviors suggests that the extension of posterior axial mesodermal cells is impaired in embryos that carry the semi-dominant N-cadherin allele. This defect most likely results from a general loss of cell-cell adhesion in the tailbud region. Consistent with these observations, N-cadherin is expressed throughout the tailbud during post-gastrulation stages. In addition, we show that N-cadherin interacts synergistically with vang-like 2, a member of the non-canonical Wnt signaling/planar cell polarity pathway, to mediate tail morphogenesis. Conclusion We provide the first evidence here that N-cadherin and other members of the classical cadherin subfamily function in parallel with the planar cell polarity pathway to shape the posterior axis during post-gastrulation stages. These findings further highlight the central role that adhesion molecules play in the cellular rearrangements that drive morphogenesis in vertebrates and identify classical cadherins as major contributors to tail development. PMID:18045497

  16. Trigeminal autonomic cephalgia caused by recurrent posterior scleritis.

    PubMed

    Alim-Marvasti, Ali; Ho, Jason; Weatherall, Mark; Patel, Maneesh; George, Sheena; Viegas, Stuart

    2016-12-01

    A 40-year-old woman presented with a side-locked headache with autonomic features, which then switched sides before reverting to the original side. The atypical features of side swapping, partial response to indometacin and abnormal optic disc appearances ultimately led to a diagnosis of recurrent posterior scleritis. We discuss the differential diagnosis of trigeminal autonomic cephalgias and its secondary causes, and provide practical pointers for its investigation and management.

  17. Pure alexia and right hemiachromatopsia in posterior dementia.

    PubMed Central

    Freedman, L; Costa, L

    1992-01-01

    A 66 year old, right handed woman presented with pure alexia and right hemiachromatopsia (PARH) in the context of a posterior dementia. PARH was accompanied by prosopagnosia, 2-D object agnosia, and environmental agnosia. Visual fields were normal to confrontation testing. The pathological anatomy of PARH involves circumscribed damage to the lingual and fusiform gyri and paraventricular white matter of the left occipital cortex, two contiguous cortical regions functionally specialised for processing colour and word form information, respectively. PMID:1619420

  18. Early treatment of posterior crossbite - a randomised clinical trial

    PubMed Central

    2013-01-01

    Background The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis. Methods This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the ‘Digimodel’ software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded. Results Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite. Conclusions Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced. Trial registration Registration trial DRKS00003497 on DRKS PMID:23339736

  19. 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.

  20. An Injectable Method for Posterior Lateral Spine Fusion

    DTIC Science & Technology

    2013-09-01

    spine area but is also used to treat diseases in the cervical and thoracic spine regions [2]. Spinal fusion has been developed with the bone...Lateral Spine Fusion PRINCIPAL INVESTIGATOR: Dr. Elizabeth Olmsted-Davis CONTRACTING ORGANIZATION: Baylor College of Medicine...Method for Posterior Lateral Spine Fusion 5b. GRANT NUMBER W81XWH-12-1-0475 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr. Elizabeth A

  1. 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

  2. Anterior and posterior centers jointly regulate Bombyx embryo body segmentation.

    PubMed

    Nakao, Hajime

    2012-11-15

    Insect embryo segmentation is largely divided into long and short germ types. In the long germ type, each segment primordium is represented on a large embryonic rudiment of the blastoderm, and segmental patterning occurs nearly simultaneously in the syncytium. In the short germ type, however, only anterior segments are represented in the small embryonic rudiment, usually located on the egg posterior, and the rest of the segments are added sequentially from the posterior growth zone in a cellular context. The long germ type is thought to have evolved from the short germ type. It is proposed that this transition, which appears to have occurred multiple times over the course of evolution, was realized through the acquisition of a localized anterior instruction center. Here, I examined the early segmentation process in the silkmoth Bombyx mori, a lepidopteran insect, in which the mechanisms of anterior-posterior (AP) axis formation have not been well analyzed. In this insect, both the long germ and short germ features have been reported. The mRNAs for two key genes involved in insect AP axis formation, orthodenticle (Bm-otd) and caudal (Bm-cad), are localized maternally in the germ anlage, where they act as anterior and posterior instruction centers, respectively. RNAi studies indicate that, while Bm-cad affects the formation of all the even skipped (Bm-eve) stripes, there is also anterior Bm-eve stripe formation activity that involves Bm-otd. Thus, there is redundancy in Bm-eve stripe formation activity that must be coordinated. Some genetic interactions, identified either experimentally or hypothetically, are also introduced, which might enable robust AP formation in this organism.

  3. 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.

  4. 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.

  5. Evaluating pathogenic dementia variants in posterior cortical atrophy

    PubMed Central

    Carrasquillo, Minerva M.; Barber, Imelda; Lincoln, Sarah J.; Murray, Melissa E.; Camsari, Gamze Balci; Khan, Qurat ul Ain.; Nguyen, Thuy; Ma, Li; Bisceglio, Gina D.; Crook, Julia E.; Younkin, Steven G.; Dickson, Dennis W.; Boeve, Bradley F.; Graff-Radford, Neill R.; Morgan, Kevin; Ertekin-Taner, Nilüfer

    2015-01-01

    Posterior cortical atrophy (PCA) is an understudied visual impairment syndrome most often due to “posterior Alzheimer’s disease (AD)” pathology. Case studies detected mutations in PSEN1, PSEN2, GRN, MAPT and PRNP in subjects with clinical PCA. To detect the frequency and spectrum of mutations in known dementia genes in PCA, we screened 124 European-American subjects with clinical PCA (n=67) or posterior AD neuropathology (n=57) for variants in genes implicated in AD, frontotemporal dementia, and prion disease using NeuroX, a customized exome array. Frequencies in PCA of the variants annotated as pathogenic or potentially pathogenic were compared against ~4,300 European-American population controls from the NHLBI Exome Sequencing Project (ESP). We identified two rare variants not previously reported in PCA, TREM2 Arg47His and PSEN2 Ser130Leu. No other pathogenic or potentially pathogenic variants were detected in the screened dementia genes. In this first systematic variant screen of a PCA cohort, we report two rare mutations in TREM2 and PSEN2, validate our previously reported APOE ε4 association, and demonstrate the utility of NeuroX. PMID:26507310

  6. 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.

  7. Congenital posterior urethral obstruction: re-do fulguration.

    PubMed

    Imaji, Reisuke; Dewan, Paddy A

    2002-09-01

    In patients with congenital posterior urethral obstruction, transurethral fulguration (TUF) is usually the treatment of choice if the patient is in a stable condition. However, few papers have described the proportion of patients who need further fulguration. We reviewed 83 boys with a congenital obstructive posterior urethral membrane (COPUM) to assess the role of re-do fulguration, as judged by prospective video recordings. Between December 1990 and March 2000, 83 boys (aged from newborn to 15 years) underwent cystourethroscopy for investigation of a urethral anomaly and were found to have a COPUM. TUF was performed endoscopically with a hook diathermy electrode. Two to 3 months later boys who had cauterisation had a further urethroscopy and diathermy as required. Of the 83 membranous lesions in the posterior urethra, 38 were considered severe, 20 moderate, and 21 minor. Four patients had inadequate data to be properly classified. Eighteen (47.4%) of the 38 patients who had a severe obstructive membrane equired further endoscopic intervention to obliterate residual membrane elements. As over 45% of patients who had a severe obstructing membrane needed further fulguration, it is important to follow patients carefully and to repeat the cystourethroscopy.

  8. Effect of four different intraocular lenses on posterior capsule opacification

    PubMed Central

    Duman, Rahmi; Karel, Fatih; Özyol, Pelin; Ateş, Can

    2015-01-01

    AIM To evaluate the impact of 4 different intraocular lenses (IOLs) on posterior capsule opacification (PCO) by comparing the neodymium: yttrium-aluminum-garnet (Nd:YAG) laser capsulotomy rates. METHODS This retrospective study included 4970 eyes of 4013 cataract patients who underwent phacoemulsification and IOL implantation between January 2000 and January 2008 by the same surgeon at one clinic. Four different IOLs were assessed. The outcome parameter was the incidence of Nd:YAG laser posterior capsulotomies. RESULTS An Nd:YAG laser posterior capsulotomy was performed in 153 (3.07%) of the 4970 eyes. The mean follow-up time was 84mo for all of the IOL groups. The percentage of eyes developing PCO was significantly greater for the acrylic hydrophilic IOLs than for the hydrophobic IOLs, although eyes with acrylic hydrophilic IOLs did not require Nd:YAG laser capsulotomy as soon as eyes with acrylic hydrophobic IOLs. There was no difference between the long-term PCO rates when 1- and 3-piece acrylic hydrophobic IOLs were compared or when IOLs made of the same material but with different haptic angles were compared. CONCLUSION In this study, eyes with acrylic hydrophilic IOLs were more likely to develop PCO than those with acrylic hydrophobic IOLs. The lens design (1-piece versus 3-piece and varying haptic angles) did not affect the PCO rate. PMID:25709920

  9. 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.

  10. Macular Development in Aggressive Posterior Retinopathy of Prematurity

    PubMed Central

    Pandya, Hemang K.; Faia, Lisa J.; Robinson, Joshua; Drenser, Kimberly A.

    2015-01-01

    Purpose. To report anatomic outcomes after early and confluent laser photocoagulation of the entire avascular retina, including areas in close proximity to the fovea, in patients with APROP. We aspire to demonstrate fundoscopic evidence of transverse growth and macular development following laser treatment in APROP. Methods. Retrospective review of 6 eyes with APROP that underwent confluent laser photocoagulation of the entire avascular retina. Photographic fundoscopic imaging was performed using the RetCam to compare outcomes after treatment. Results. Mean birth weight and gestational age were 704.8 g and 24.33 weeks, respectively. There were 2 females and 1 male. The average time to laser was 9.3 weeks after birth, with the mean postmenstrual age of 34 weeks. Two eyes had zone 1 and 4 eyes had posterior zone 2 disease. Three eyes developed 4A detachments, which were successfully treated. All 6 eyes experienced transverse growth, with expansion of the posterior pole and anterior displacement of the laser treatment. Conclusion. Confluent photocoagulation of the entire avascular retina, regardless of foveal proximity, should be the mainstay for treating APROP. Examination should be conducted within 5–10 days to examine areas previously hidden by neovascularization to ensure prudent therapy. Macular development involves both transverse and anterior-posterior growth. PMID:26167498

  11. Macular Development in Aggressive Posterior Retinopathy of Prematurity.

    PubMed

    Pandya, Hemang K; Faia, Lisa J; Robinson, Joshua; Drenser, Kimberly A

    2015-01-01

    Purpose. To report anatomic outcomes after early and confluent laser photocoagulation of the entire avascular retina, including areas in close proximity to the fovea, in patients with APROP. We aspire to demonstrate fundoscopic evidence of transverse growth and macular development following laser treatment in APROP. Methods. Retrospective review of 6 eyes with APROP that underwent confluent laser photocoagulation of the entire avascular retina. Photographic fundoscopic imaging was performed using the RetCam to compare outcomes after treatment. Results. Mean birth weight and gestational age were 704.8 g and 24.33 weeks, respectively. There were 2 females and 1 male. The average time to laser was 9.3 weeks after birth, with the mean postmenstrual age of 34 weeks. Two eyes had zone 1 and 4 eyes had posterior zone 2 disease. Three eyes developed 4A detachments, which were successfully treated. All 6 eyes experienced transverse growth, with expansion of the posterior pole and anterior displacement of the laser treatment. Conclusion. Confluent photocoagulation of the entire avascular retina, regardless of foveal proximity, should be the mainstay for treating APROP. Examination should be conducted within 5-10 days to examine areas previously hidden by neovascularization to ensure prudent therapy. Macular development involves both transverse and anterior-posterior growth.

  12. Ganglion cyst on the posterior cruciate ligament: a case report

    PubMed Central

    Durante, Jaclyn A.

    2009-01-01

    Objective: To present the diagnostic and clinical features of a ganglion cyst located on the posterior cruciate ligament and create awareness amongst clinicians of this uncommon diagnosis. Clinical Features: A 24-year old woman complaining of intermittent left knee pain brought on by an increase in mileage during her training for a half-marathon. A diagnosis of mild chondromalacia patella and a ganglion cyst on the posterior cruciate ligament was made via diagnostic imaging. Intervention and outcome: Patient was followed up with imaging. The patient chose to withdraw a surgical consult due to patient preference. No conservative treatment was provided. Conclusion: Although chondromalacia patella is the more probable, a secondary diagnostic consideration in this patient could be a ganglion cyst. A ganglion cyst on the posterior cruciate ligament is an uncommon diagnosis and the clinical manifestations are variable and non-specific. It is important to be aware of its clinical features and to obtain appropriate methods of imaging to generate the diagnosis promptly. PMID:20037698

  13. Frontal-posterior coherence and cognitive function in older adults.

    PubMed

    Fleck, Jessica I; Kuti, Julia; Brown, Jessica; Mahon, Jessica R; Gayda-Chelder, Christine

    2016-12-01

    The reliable measurement of brain health and cognitive function is essential in mitigating the negative effects associated with cognitive decline through early and accurate diagnosis of change. The present research explored the relationship between EEG coherence for electrodes within frontal and posterior regions, as well as coherence between frontal and posterior electrodes and performance on standard neuropsychological measures of memory and executive function. EEG coherence for eyes-closed resting-state EEG activity was calculated for delta, theta, alpha, beta, and gamma frequency bands. Participants (N=66; mean age=67.15years) had their resting-state EEGs recorded and completed a neuropsychological battery that assessed memory and executive function, two cognitive domains that are significantly affected during aging. A positive relationship was observed between coherence within the frontal region and performance on measures of memory and executive function for delta and beta frequency bands. In addition, an inverse relationship was observed for coherence between frontal and posterior electrode pairs, particularly within the theta frequency band, and performance on Digit Span Sequencing, a measure of working memory. The present research supports a more substantial link between EEG coherence, rather than spectral power, and cognitive function. Continued study in this area may enable EEG to be applied broadly as a diagnostic measure of cognitive ability.

  14. 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

  15. Evidence for extra radiation? Profile likelihood versus Bayesian posterior

    SciTech Connect

    Hamann, Jan

    2012-03-01

    A number of recent analyses of cosmological data have reported hints for the presence of extra radiation beyond the standard model expectation. In order to test the robustness of these claims under different methods of constructing parameter constraints, we perform a Bayesian posterior-based and a likelihood profile-based analysis of current data. We confirm the presence of a slight discrepancy between posterior- and profile-based constraints, with the marginalised posterior preferring higher values of the effective number of neutrino species N{sub eff}. This can be traced back to a volume effect occurring during the marginalisation process, and we demonstrate that the effect is related to the fact that cosmic microwave background (CMB) data constrain N{sub eff} only indirectly via the redshift of matter-radiation equality. Once present CMB data are combined with external information about, e.g., the Hubble parameter, the difference between the methods becomes small compared to the uncertainty of N{sub eff}. We conclude that the preference of precision cosmological data for excess radiation is 'real' and not an artifact of a specific choice of credible/confidence interval construction.

  16. Bacillus Panophthalmitis with Posterior Extension to the Prechiasmatic Optic Nerve

    PubMed Central

    Notz, Gregory M.

    2016-01-01

    A rare case of Bacillus panophthlamitis with extension to the prechiasmatic optic nerve secondary to hematogenous spreading after intravenous drug use is presented. A 27-year-old man with a recent history of trauma to the left eye presented with severe left eye pain following a binge of intravenous drug use. Visual acuity (VA) was LP. On examination he had chemosis, proptosis, elevated intraocular pressure, and a complete hyphema. CT-scan identified preseptal swelling, but no evidence of any posterior extension of the anterior process or orbital fractures. Topical and systemic therapy were initiated. On follow-up clinical examination less than 12 hours after presentation he had signs of a keratitis with worsening ophthalmoplegia and repeat imaging demonstrated posterior extension to the prechiasmatic optic nerve. Shortly after the cornea ruptured with cultures growing Bacillus. The patient underwent enucleation and has had no further progression of infection. To the best of our knowledge, this is the first report of Bacillus panophthalmitis presenting with signs of trauma with posterior extension to the prechiasmatic optic nerve. PMID:27994900

  17. Surgical management of unruptured posterior carotid artery wall aneurysms.

    PubMed

    O'Shaughnessy, Brian A; Getch, Christopher C; Bendok, Bernard R; Batjer, H Hunt

    2003-07-15

    Intracranial aneurysms arising from the posterior wall of the supraclinoid carotid artery are extremely common lesions. The aneurysm dilation typically occurs in immediate proximity to the origin of the posterior communicating artery and, less commonly, the anterior choroidal artery (AChA). Because of the increasingly widespread use of noninvasive neuroimaging methods to evaluate patients believed to harbor cerebral lesions, many of these carotid artery aneurysms are now documented in their unruptured state, prior to occurrence of subarachnoid hemorrhage. Based on these factors, the management of unruptured posterior carotid artery (PCA) wall aneurysms is an important element of any neurosurgical practice. Despite impressive recent advances in endovascular therapy, the placement of microsurgical clips to exclude aneurysms with preservation of all afferent and efferent vasculature remains the most efficacious and durable therapy. To date, an optimal outcome is only achieved when the neurosurgeon is able to combine systematic preoperative neurovascular assessment with meticulous operative technique. In this report, the authors review their surgical approach to PCA wall aneurysms, which is greatly based on the extensive neurovascular experience of the senior author. Focus is placed on their methods of preoperative evaluation and operative technique, with emphasis on neurovascular anatomy and the significance of oculomotor nerve compression. They conclude by discussing surgery-related complications, with a particular focus on intraoperative rupture of aneurysms and their management, and the postoperative ischemic AChA syndrome.

  18. Aspects of treatment for posterior heel pain in young athletes

    PubMed Central

    Elengard, Thomas; Karlsson, Jón; Silbernagel, Karin Grävare

    2010-01-01

    Posterior heel pain occurs in young athletes involved in running and jumping. Due to the pain, the child often limits his/her physical activity level, with a possible negative effect on health and well-being. Although numerous research studies have examined the cause and treatment of heel and Achilles tendon pain in adults, there are no randomized clinical trials on treatment in children and adolescents. Therefore, there is limited evidence for how to treat young athletes with this type of complaint. The purpose of this review was to analyze critically and summarize the literature in regards to the cause and treatment of posterior heel pain in young athletes. The various diagnoses and clinical presentations relating to posterior heel and Achilles tendon pain are discussed. The theory and mechanism behind various recommended treatment strategies are also reviewed in the context of use in the young athlete. In summary, it is important to perform a thorough evaluation of each young athlete with heel pain to determine the appropriate diagnosis and to treat the deficits found and allow for a gradual progression to training. However, the recommendations at this time are based on clinical experience and a few retrospective studies, so further well designed prospective studies with validated outcome measures are urgently needed for the young athlete. PMID:24198561

  19. 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.

  20. 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.

  1. [Kocher-Langenbeck approach in the surgical management of posterior wall fractures of the acetabulum].

    PubMed

    Fernández-Palomo, L J

    2016-01-01

    Surgical treatment of acetabular fractures is indicated in displaced cases in order to restore and stabilize the hip joint and the pelvic ring integrity. Posterior structure fractures must be treated through posterior pelvic surgical approaches. The Kocher-Langenbeck is the most recommended approach for the majority of posterior acetabular fractures.

  2. 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

  3. Factors predicting surgical site infection after posterior lumbar surgery

    PubMed Central

    Wang, Tao; Wang, Hui; Yang, Da-Long; Jiang, Li-Qiang; Zhang, Li-Jun; Ding, Wen-Yuan

    2017-01-01

    Abstract This is a retrospective study. The purpose of this study is to explore incidence and risk factors for surgical site infection (SSI) after posterior lumbar surgery. SSI is a common complication after posterior lumbar surgery, bringing mental and physical pain and prolonging hospital stay. However, predisposing factors, as reported less, remain controversial. Patients who underwent posterior lumbar surgery at 3 centers between 2006 and 2016 were included. The possible factors include 3 aspects: demographic variables-age, sex, body mass index (BMI), waist-to-hip radio (WHR), hypertension, diabetes, heart disease, smoking, drinking, steroidal injection, surgical time between June and September, preoperative shower; blood test variables-white blood cell (WBC), neutrophil, red blood cell (RBC), hemoglobin (Hb), total protein (TP), albumin, albumin/globulin (A/G), C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR) and surgical related variables-operation time, blood loss, operative level, instrumentation, incision length. Factors related with SSI were also performed by multivariate analysis. The prevalence of SSI was 3.00% (267 cases of 8879) had a postoperative wound infection. There were significant difference in WHR (0.92 vs 0.83), WBC (4.31 vs 6.69), TP (58.7 vs 65.2), albumin (36.9 vs 43.2), CRP (2.01 vs 0.57), PCT (0.097 vs 0.067), operation time (217.9 vs 195.7), blood loss (997.1 vs 915.3) and operative level (3.05 vs 2.45) and incision length (24.1 vs 20.0) between SSI group and non-SSI group. >60 years old, female, BMI <18.5 and >30.0, diabetes, male smoking, preoperative steroidal injection, surgical time between June and September, no preoperative shower, instrumentation surgery were risk factors for SSI after posterior lumbar surgery. Many factors, >60 years old, female, BMI, WHR, diabetes, male smoking, preoperative steroidal injection, surgical time between June and September, preoperative shower, WBC, TP, albumin

  4. Vascular Complications in Arthroscopic Repair Of Posterior Cruciate Ligament

    PubMed Central

    Agotegaray, Juan Ignacio; Comba, Ignacio; Bisiach, Luciana; Grignaffini, María Emilia

    2017-01-01

    Introduction: Posterior cruciate ligament is the primary stabilizer of the knee. Among the potential complications in arthroscopic repair of this ligament, there are vascular lesions, due to laceration, thrombosis and injury of the intima of the popliteal artery. We used one case to show the vascular complications that may arise in arthroscopic repair of the posterior cruciate ligament, how to handle it and the results. Methods: One patient, 33 years old, with a history of traffic accident. In a physical exam the patient shows pain and swelling of the knee, positive posterior drawer test and positive Godfrey test. X-rays on the knee show posterior tibial translation and MRI a complete fibers rupture at the middle third of the posterior cruciate ligament. An arthroscopic repair surgery was scheduled three weeks after trauma, with PCL reconstruction using simple band technique.After surgical intervention, hemostatic cuff was released, no peripheral pulse, paleness and coldness of the member was confirmed. An arteriography was carried out, which confirmed absences of distal vascular filling in the popliteal artery. An urgent referral was carried out with Vascular Surgery Services, who had been informed of the surgery previously (a notification that is part of our routine for this kind of interventions). Arteriorrhaphy and venorrhaphy of the popliteal arteries was fulfilled 12 hours later, with a leg fasciotomy. Daily monitoring was performed, and after 72 hours, muscle necrosis is seen with wound drainage, analysis shows presence of gram-negative bacilli, Proteus Mirabilis-Pseudomonas spp and the lab results showed leukocytes: 8.700/ml, ESR: 58, CRP: 48. A new surgery is performed with complete resection of the anterior external compartment of the leg, and a system of continuous cleansing is applied with physiological saline solution and boric acid for 14 days until drainage is eliminated. Vancomycin and ceftazidime EV was indicated for 14 days and, after a good

  5. Reverse engineering quantum field theory

    NASA Astrophysics Data System (ADS)

    Oeckl, Robert

    2012-12-01

    An approach to the foundations of quantum theory is advertised that proceeds by "reverse engineering" quantum field theory. As a concrete instance of this approach, the general boundary formulation of quantum theory is outlined.

  6. Dielectrophoresis of reverse phase emulsions.

    PubMed

    Flores-Rodriguez, N; Bryning, Z; Markx, G H

    2005-08-01

    Reverse miniemulsions, emulsions of droplets of size 200 nm-1 microm of a polar liquid dispersed in an apolar continuous liquid phase, exhibit strong electrokinetic responses in low-frequency electric fields. The electrokinetic behaviour of a reverse miniemulsion, previously developed for use as electronic paper, has been investigated under static and flow conditions, in uniform and non-uniform electric fields. Results reveal that when using frequencies lower than 10 Hz strong aggregation of the droplets occurs. In uniform electric fields, under static conditions, droplets reversibly aggregate into honeycomb-like or irregular aggregates. Under flow conditions, droplets aggregate into approximately equidistant streams. In non-uniform electric fields the droplets reversibly aggregate in high-field regions, and can be guided along regions of high field strength in a flow. The potential of the technique for the formation of structured materials is discussed.

  7. 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.

  8. FGF2 antagonizes aberrant TGFβ regulation of tropomyosin: role for posterior capsule opacity.

    PubMed

    Kubo, Eri; Shibata, Shinsuke; Shibata, Teppei; Kiyokawa, Etsuko; Sasaki, Hiroshi; Singh, Dhirendra P

    2016-12-15

    Transforming growth factor (TGF) β2 and fibroblast growth factor (FGF) 2 are involved in regulation of posterior capsule opacification (PCO) and other processes of epithelial-mesenchymal transition (EMT) such as cancer progression, wound healing and tissue fibrosis as well as normal embryonic development. We previously used an in vivo rodent PCO model to show the expression of tropomyosin (Tpm) 1/2 was aberrantly up-regulated in remodelling the actin cytoskeleton during EMT. In this in vitro study, we show the Tpms family of cytoskeleton proteins are involved in regulating and stabilizing actin microfilaments (F-actin) and are induced by TGFβ2 during EMT in lens epithelial cells (LECs). Importantly, we found TGFβ2 and FGF2 played contrasting roles. Stress fibre formation and up-regulation of α-smooth muscle actin (αSMA) induced by TGFβ2 could be reversed by Tpm1/2 knock-down by siRNA. Expression of Tpm1/2 and stress fibre formation induced by TGFβ2 could be reversed by FGF2. Furthermore, FGF2 delivery to TGFβ-treated LECs perturbed EMT by reactivating the mitogen-activated protein kinase (MAPK)/ extracellular signal-regulated kinase (ERK) pathway and subsequently enhanced EMT. Conversely, MEK inhibitor (PD98059) abated the FGF2-mediated Tpm1/2 and αSMA suppression. However, we found that normal LECs which underwent EMT showed enhanced migration in response to combined TGFβ and FGF2 stimulation. These findings may help clarify the mechanism reprogramming the actin cytoskeleton during morphogenetic EMT cell proliferation and fibre regeneration in PCO. We propose that understanding the physiological link between levels of FGF2, Tpm1/2 expression and TGFβs-driven EMT orchestration may provide clue(s) to develop therapeutic strategies to treat PCO based on Tpm1/2.

  9. 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.

  10. Reversible jump Markov chain Monte Carlo for deconvolution.

    PubMed

    Kang, Dongwoo; Verotta, Davide

    2007-06-01

    To solve the problem of estimating an unknown input function to a linear time invariant system we propose an adaptive non-parametric method based on reversible jump Markov chain Monte Carlo (RJMCMC). We use piecewise polynomial functions (splines) to represent the input function. The RJMCMC algorithm allows the exploration of a large space of competing models, in our case the collection of splines corresponding to alternative positions of breakpoints, and it is based on the specification of transition probabilities between the models. RJMCMC determines: the number and the position of the breakpoints, and the coefficients determining the shape of the spline, as well as the corresponding posterior distribution of breakpoints, number of breakpoints, coefficients and arbitrary statistics of interest associated with the estimation problem. Simulation studies show that the RJMCMC method can obtain accurate reconstructions of complex input functions, and obtains better results compared with standard non-parametric deconvolution methods. Applications to real data are also reported.

  11. Posterior femoral condylar offset after total knee replacement in the risk of knee flexion contracture.

    PubMed

    Onodera, Tomohiro; Majima, Tokifumi; Nishiike, Osamu; Kasahara, Yasuhiko; Takahashi, Daisuke

    2013-08-01

    The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

  12. 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.

  13. Isolation, purification, and characterization of avian antimicrobial glycopeptide from the posterior salivary gland of Sepia pharaonis.

    PubMed

    Karthik, R; Saravanan, R; Ebenezar, K Kumar; Sivamalai, T

    2015-02-01

    A proteinaceous glycopeptide was isolated from the posterior salivary gland (PSG) of Sepia pharaonis by gel (Sephadex G-100) filtration chromatography and purified by reversed-phase high-performance liquid chromatography (RP-HPLC). Among the collected fractions, fraction 12 showed a retention time (RT) of 31 min. The total protein and neutral sugar contents of the purified glycopeptide were recorded as 68.14 and 2.95 mg, respectively. The molecular weight of the purified glycopeptide was found to be ~50 kDa. The infrared (IR) and circular dichroism (CD) spectroscopy confirmed the presence of peptide and secondary structure in the purified glycopeptide. The antibacterial activity of the purified glycopeptide against avian bacterial strains was also determined. Gas chromatography-mass spectrometry (GC-MS) of the purified glycopeptide revealed the likely compounds for the antibacterial activity such as 22, 23-dibromostigmasterol acetate, 3-methyl 2-(2-oxypropyl) furan, and 2,4,4-trimethyl-3-hydroxymethyl-5A-(3-methyl-but-2-enyl)-cyclohexene. These three compounds found in the purified glycopeptide could be responsible for the antibacterial activity against the avian pathogens. The results of this study suggest that the purified glycopeptide from the PSG of S. pharaonis could be an antibacterial agent against avian bacterial pathogens.

  14. Differential mechanisms for insulin-induced relaxations in mouse posterior tibial arteries and main mesenteric arteries.

    PubMed

    Qu, Dan; Liu, Jian; Lau, Chi Wai; Huang, Yu

    2014-12-01

    The characteristics of endothelium-dependent relaxations in response to insulin and acetylcholine (ACh) in the mouse posterior tibial artery (PTA) were studied on wire myograph, and compared to those in the mouse main mesenteric artery (MMA). Insulin-induced relaxation in PTA was reversed by PI3K and Akt inhibitors, LY294002 and triciribine, but not by nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME) or guanylate cyclase inhibitor, ODQ. The relaxation in PTA was also inhibited by apamin (small-conductance Ca(2+)-activated K(+) channel blocker) plus charybdotoxin (intermediate-conductance Ca(2+)-activated K(+) channel blocker), elevated KCl or ouabain (Na(+)-K(+) ATPase inhibitor) plus BaCl(2) [inwardly rectifying K(+) (K(IR)) channel inhibitor]; whereas L-NAME but not triciribine inhibited ACh-induced relaxation in PTA. On the other hand, nitric oxide and endothelium-derived hyperpolarizing factor albeit to a less extent mediated both insulin- and ACh-induced relaxations in MMA. The present study is for the first time dissecting out the components of endothelium-dependent relaxation in mouse PTA and suggesting differential responses to different agonists in distinctive blood vessels.

  15. 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

  16. 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'.

  17. 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.

  18. Cortical subarachnoid hemorrhage associated with reversible cerebral vasoconstriction syndrome after elective triplet cesarean delivery.

    PubMed

    Albano, Beatrice; Del Sette, Massimo; Roccatagliata, Luca; Gandolfo, Carlo; Primavera, Alberto

    2011-06-01

    Reversible cerebral vasoconstriction syndromes (RCVS) comprise a group of disorders characterized by prolonged, but reversible vasoconstriction of the cerebral arteries, usually associated with acute-onset, severe, recurrent headaches, with or without additional neurological signs and symptoms. Various complications of this condition have been observed, such as cortical subarachnoid hemorrhages (cSAH), intracerebral hemorrhages, reversible posterior leukoencephalopathy, ischaemic strokes and transient ischaemic attacks. It is important to include RCVS in thunderclap headache differential diagnosis and among non-aneurismatic subarachnoid hemorrhage causes. In the past years, thanks to the major diffusion of new diagnostic tools such as magnetic resonance, computed tomography and digital subtraction angiography, RCVS have been demonstrated to be more frequent than previously thought. We report an illustrative case of a woman affected by a small cSAH, associated to RCVS, after elective triplet cesarean delivery. To our knowledge, this is the first case of cSAH associated to RCVS after a triplet pregnancy.

  19. Posterior patterning by the Caenorhabditis elegans even-skipped homolog vab-7.

    PubMed

    Ahringer, J

    1996-05-01

    Patterning of the posterior end in animals is not well understood. Homologs of Drosophila even-skipped (eve) have a similar posterior expression pattern in many animals, and in vertebrates they are linked physically to the "posterior" ends of homeotic clusters (HOM-C), suggesting a conserved role in posterior development. However, the function of this posterior expression is not known. Here I show that the Caenorhabditis elegans gene vab-7 encodes an eve homolog that is required for posterior development and expressed in a pattern strikingly similar to that of vertebrate eve genes. Using a four-dimensional recording system, I found that posterior body muscles and the posterior epidermis are patterned abnormally in vab-7 mutants, but commitment to muscle and epidermal fates is normal. Furthermore, vab-7 activity is required for the complete expression of the most posterior HOM-C gene egl-5 in muscle cells, supporting the idea that eve homologs may act with the HOM-C to determine posterior cell fates. The conservation of sequence and expression pattern between vab-7 and eve homologs in other animals argues that most eve genes have posterior mesodermal and ectodermal patterning functions.

  20. Posterior compartment defect repair in vaginal surgery: update on surgical techniques.

    PubMed

    Ginger, Van Anh T; Kobashi, Kathleen C

    2007-09-01

    Posterior colporrhaphy has been the most common surgical technique for the repair of posterior compartment defects. Traditional posterior colporrhaphy involves plication of the levator ani, which may result in dyspareunia related to narrowing of the introitus. Current posterior compartment repairs either plicate the midline fascia or repair the specific site of fascial weakness. Despite insubstantial data, the use of grafts to reinforce posterior repairs has gained popularity. Grafts such as allografts, xenografts, and synthetic meshes have been used to reinforce the posterior wall. Complications include infection and erosion, as well as recurrence of prolapse. Minimally invasive techniques have been developed to recreate the apical support of the vaginal vault and repair the posterior prolapse. Properly conducted randomized prospective trials are needed to adequately assess these new approaches.

  1. 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

  2. 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.

  3. Reversible Rings with Involutions and Some Minimalities

    PubMed Central

    Fakieh, W. M.; Nauman, S. K.

    2013-01-01

    In continuation of the recent developments on extended reversibilities on rings, we initiate here a study on reversible rings with involutions, or, in short, ∗-reversible rings. These rings are symmetric, reversible, reflexive, and semicommutative. In this note we will study some properties and examples of ∗-reversible rings. It is proved here that the polynomial rings of ∗-reversible rings may not be ∗-reversible. A criterion for rings which cannot adhere to any involution is developed and it is observed that a minimal noninvolutary ring is of order 4 and that a minimal noncommutative ∗-reversible ring is of order 16. PMID:24489510

  4. Human posterior auditory cortex gates novel sounds to consciousness

    PubMed Central

    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.

    2004-01-01

    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 (≈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. PMID:15096618

  5. 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.

  6. Minimally invasive tubular access for posterior cervical foraminotomy

    PubMed Central

    Branch, Byron C.; Hilton, Donald L.; Watts, Clark

    2015-01-01

    Background: Minimally invasive tubular access for posterior cervical foraminotomy can be an effective and safe technique for decompression of the nerve root utilizing minimally invasive muscle splitting with routine outpatient discharge. This technique has come under scrutiny calling into question the associated learning curve, a subjective limited exposure provided, and an argument that the risks and complications are largely unknown. In response to previously published critiques, this study aims to describe the outcomes and complications associated with this technique in a large patient series. Methods: A retrospective chart review was performed from 1999 to 2013 capturing a single surgeon's experience with the minimally invasive tubular access for posterior cervical foraminotomy technique from a single institution, encompassing 463 patients. Surgical outcome documented at follow-up and complications were obtained from this patient series. Additional variables analyzed include: Hospital length of stay, number of levels operated, targeted root for decompression, side operated, length of surgery, and estimated blood loss. Results: Outpatient discharge was achieved in 91.6% of cases. There were 10 complications (2.2%) among the 463 patients undergoing this technique from 1999 to 2013. Patients were followed for an average of 1 year and 2 months postoperatively. Improvement from the preoperative condition was observed in 98.2% of patients and excellent outcomes with patients reporting complete relief of symptoms with no or mild residual discomfort was seen in 92.2%. Conclusions: Compared with open techniques, minimally invasive tubular access for posterior cervical foraminotomy demonstrates comparable, if not superior, complication rates, and patient outcomes. PMID:26009705

  7. 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.

  8. Posterior Lumbar Interbody Fusion via a Unilateral Approach

    PubMed Central

    Shin, Hyun Chul; Yi, Seong; Kim, Sang Hyun; Yoon, Do Heum

    2006-01-01

    This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK™ (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain. PMID:16807980

  9. Management of Cerebrospinal Fluid Leak following Posterior Cranial Fossa Surgery

    PubMed Central

    Altaf, Imran; Vohra, Anjum Habib; Shams, Shahzad

    2016-01-01

    Objective: Cerebrospinal fluid leakage remains a significant cause of morbidity following posterior fossa surgery, and its treatment remains a difficult problem. The aim of the study was to propose a treatment algorithm for its management. Methods: A retrospective, single-center study was conducted on 147 patients who underwent elective posterior fossa surgery for a variety of diseases. Patients with post operative CSF leakage had either been treated initially with conservative measures including re-suturing of the wound, with CSF lumbar drainage to be employed in case the CSF leakage didn’t stop, or the initial intervention was the institution of CSF lumbar drainage simultaneously with conservative measures. VP (ventriculo-peritoneal) shunt was done in patients with gross hydrocephalus on postoperative CT brain. Results: There were 25 (17%) cases of CSF leakage, including 24 incisional CSF leaks and one case of CSF otorrhea. In eight patients with incisional CSF leakage treated initially with conservative measures including re-suturing of the wound, CSF leakage stopped in only two cases. CSF lumbar drainage instituted later on in six cases with persistent leakage stopped the CSF leakage. In fourteen patients managed initially with re-suturing of the wound and concomitant CSF lumbar drainage, CSF leakage settled in all the cases. Two patients with gross hydrocephalus on post operative CT were managed successfully with VP shunt. Re-suturing of the wound with concomitant CSF lumbar drainage was found to be significantly associated (p=0.003) with the stoppage of CSF leakage, and the settlement of meningitis (p= 0.014). Conclusion: Incisional CSF leaks after posterior fossa surgery should be managed with re-suturing of the wound and concomitant CSF lumbar drainage, instead of an initial trial of conservative therapy alone. PMID:28083041

  10. Evaluation of posterior clinoid process pneumatization by multidetector computed tomography.

    PubMed

    Burulday, Veysel; Akgül, Mehmet Hüseyin; Muluk, Nuray Bayar; Ozveren, Mehmet Faik; Kaya, Ahmet

    2016-10-21

    In the present study, we investigated the types and ratio of posterior clinoid process (PCP) pneumatization in paranasal sinus multidetector computed tomography (MDCT). Paranasal MDCT images of 541 subjects (227 males, 314 females), between 15 and 65 years old, were included into the study. Pneumatization of anterior clinoid process and pneumatization types (I, II, or III) were evaluated in the males and females. PCP pneumatization was detected in 20.7 % of the males and 11.5 % of the females. Right, left, and bilateral PCP pneumatizations were detected in 7.9, 5.7, and 7.0 % of the males and 2.9, 3.2, and 4.5 % of the females, respectively. PCP pneumatization of the males is significantly higher than the females. The most detected type of pneumatization was type I (61.2 %) for all groups. In right, left, and bilateral pneumatizations separately, type I pneumatization was the most detected pneumatization type with the ratio of the 70.4, 65.2, and 50.0 %, respectively. In males, type I (61.7 %), and similarly in females, type I (60.6 %) pneumatization were detected more. Type II and type III pneumatizations were detected in decreasing order in both groups. In younger subjects, pneumatization of posterior clinoid process was found as higher, and in older subjects, PCP pneumatization was found as lower. Sclerosis process related to the aging may be responsible for the lower pneumatization ratios in older subjects. Structure of the surrounding regions of PCP is important for surgical procedures related to cavernous sinus, basilar apex aneurysms, and mass lesions. Preoperative radiological examinations are useful for operative planning. Any anomalies to PCP can cause unnecessary injury to the neurovascular complex structure around the cavernous sinus or postclinoidectomy CSF fistulas. Posterior clinoidectomies should be avoided in patients with type III PCP pneumatization to prevent CSF fistulas.

  11. Characteristic clinical features associated with aggressive posterior retinopathy of prematurity.

    PubMed

    Ahn, Y J; Hong, K E; Yum, H R; Lee, J H; Kim, K S; Youn, Y A; Park, S H

    2017-02-24

    PurposeTo identify the risk factors for, and clinical features and treatment outcomes of aggressive posterior retinopathy of prematurity (APROP) in Korean infants.MethodsAmong 770 premature infants who underwent screening, 105 infants (198 eyes, 13.63%) received treatment for ROP. A total of 24 infants (48 eyes, 3.12%) developed APROP while 81 infants (150 eyes, 10.52%) developed non-APROP treatment-requiring type. The medical records of ROP-treated infants were reviewed retrospectively. The associated systemic and maternal risk factors were analyzed and anatomical outcomes were compared according to the severity of ROP and treatment modalities.ResultsThe mean gestational age and birth weight at birth in the APROP group were significantly lower than those in the non-APROP group (P=0.019, P<0.001, respectively). Infants who were born small for their GA developed APROP more frequently than non-APROP patients (P<0.001). Chorioamnionitis-positive infants also showed higher incidence rate of APROP (APROP vs non-APROP; P<0.001 and zone I APROP vs posterior zone II APROP; P=0.036, respectively). Infants with APROP required heavier laser treatment with a higher retreatment rate compared to infants with non-APROP. Favorable anatomical outcomes were achieved in 95.3% from treatment-requiring non-APROP group, 85.7% from zone I APROP and 84.6% from posterior zone II APROP group.ConclusionIntrauterine growth restriction and chorioamnionitis were associated with development of APROP. These findings suggest that perinatal maternal environment inhibiting normal retinal vascular growth in utero may contribute to increasing the risk of APROP in premature infants.Eye advance online publication, 24 February 2017; doi:10.1038/eye.2017.18.

  12. Robotic mitral valve repair for degenerative posterior leaflet prolapse

    PubMed Central

    Javadikasgari, Hoda; Suri, Rakesh M.; Tappuni, Bassman; Lowry, Ashley M.; Mihaljevic, Tomislav; Mick, Stephanie

    2017-01-01

    Background Robotic mitral valve (MV) repair is the least invasive surgical approach to the MV and provides unparalleled access to the valve. We sought to assess technical aspects and clinical outcomes of robotic MV repair for isolated posterior leaflet prolapse by examining the first 623 such cases performed in a tertiary care center. Methods We reviewed the first 623 patients (mean age 56±9.7 years) with isolated posterior leaflet prolapse who underwent robotic primary MV repair from 01/2006 to 11/2013. All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. Results MV repair was attempted in all patients; 622 (99.8%) underwent MV repair and only 1 (0.2%) converted to replacement. After an initial attempt at robotic MV repair, 8 (1.3%) patients were converted to sternotomy as a result of management of residual mitral regurgitation (n=3), bleeding (n=1), difficulties with surgical exposure (n=2), aortic valve injury (n=1), and aortic dissection (n=1). Intraoperative post-repair echocardiography confirmed that all patients left the operating room with MR graded as mild or less, and pre-discharge echocardiography confirmed mild or less MR in 573 (99.1%). There was no hospital death, sternal wound infection, or renal failure. Seven (1.1%) patients suffered a stroke, 11 (1.8%) patients underwent re-exploration for bleeding, and 111 (19%) experienced new-onset atrial fibrillation. The mean intensive care unit length of stay and hospital length of stay were 29±17 hours and 4.6±1.6 days, respectively. Conclusions At a large tertiary care referral center, robotic MV repair for posterior prolapse is associated with zero mortality, infrequent operative morbidity, and near 100% successful repair. The combination of a patient selection algorithm and increased experience improved clinical outcomes and procedural efficiency. PMID:28203538

  13. Multi-Electrode Array for Transcutaneous Lumbar Posterior Root Stimulation.

    PubMed

    Krenn, Matthias; Hofstoetter, Ursula S; Danner, Simon M; Minassian, Karen; Mayr, Winfried

    2015-10-01

    Interest in transcutaneous electrical stimulation of the lumbosacral spinal cord is increasing in human electrophysiological and clinical studies. The stimulation effects on lower limb muscles depend on the depolarization of segmentally organized posterior root afferents and, thus, the rostro-caudal stimulation site. In previous studies, selective stimulation was achieved by varying the positions of single self-adhesive electrodes over the thoracolumbar spine. Here, we developed a multi-electrode surface array consisting of 3 × 8 electrode pads and tested its stimulation-site specificity. The array was placed longitudinally over the spine covering the T10-L2 vertebrae. Two different hydrogel layer configurations were utilized: a single layer adhered to all electrode pads of the array and a configuration comprised of eight separate strips attached to the three transverse electrode pads of each level. Voltage measurements demonstrated that an effectively focused field distribution along the longitudinal extent of the array was not accomplished when using the single continuous hydrogel layer, and segmental selective stimulation of the posterior root afferents was not possible. The separate strips produced a focused electric field distribution at the rostro-caudal level of the electrode pads selected for stimulation. This configuration allowed for the preferential elicitation of posterior root-muscle reflexes in either the L2-L4 innervated quadriceps or the L5-S2 innervated triceps surae muscle groups. Such multi-electrode array for transcutaneous spinal cord stimulation shall allow for improved control of stimulation conditions in electrophysiological studies and time-dependent and site-specific stimulation patterns for neuromodulation applications.

  14. Large radiopaque lesion in the posterior mandible: A challenging case

    PubMed Central

    Sasirekha, B.; Mathew, Philips; Ganeshkumar, M.; Austin, Ravi David; Prabhu, Raj

    2016-01-01

    Radiopaque lesions of the jawbones are frequently encountered in dental radiographs. A variety of conditions such as chronic inflammation, soft tissue calcifications, fibrosseous lesions, odontogenic tumors, and bone neoplasms can manifest as radiopaque lesions on the jawbones. These radiopaque lesions are often difficult to distinguish from each other, hence making the formulation of differential diagnosis challenging. A thorough patient's history and clinical examination supplemented by appropriate investigations will enable the clinician in narrowing down the differential diagnosis and to identify the condition accurately. Presented here is a case of the large radiopaque lesion on posterior mandible surrounded by lytic areas in a 20-year-old male patient. PMID:27829771

  15. 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

  16. Consolidation of Complex Events via Reinstatement in Posterior Cingulate Cortex

    PubMed Central

    Keidel, James L.; Ing, Leslie P.; Horner, Aidan J.

    2015-01-01

    It is well-established that active rehearsal increases the efficacy of memory consolidation. It is also known that complex events are interpreted with reference to prior knowledge. However, comparatively little attention has been given to the neural underpinnings of these effects. In healthy adults humans, we investigated the impact of effortful, active rehearsal on memory for events by showing people several short video clips and then asking them to recall these clips, either aloud (Experiment 1) or silently while in an MRI scanner (Experiment 2). In both experiments, actively rehearsed clips were remembered in far greater detail than unrehearsed clips when tested a week later. In Experiment 1, highly similar descriptions of events were produced across retrieval trials, suggesting a degree of semanticization of the memories had taken place. In Experiment 2, spatial patterns of BOLD signal in medial temporal and posterior midline regions were correlated when encoding and rehearsing the same video. Moreover, the strength of this correlation in the posterior cingulate predicted the amount of information subsequently recalled. This is likely to reflect a strengthening of the representation of the video's content. We argue that these representations combine both new episodic information and stored semantic knowledge (or “schemas”). We therefore suggest that posterior midline structures aid consolidation by reinstating and strengthening the associations between episodic details and more generic schematic information. This leads to the creation of coherent memory representations of lifelike, complex events that are resistant to forgetting, but somewhat inflexible and semantic-like in nature. SIGNIFICANCE STATEMENT Memories are strengthened via consolidation. We investigated memory for lifelike events using video clips and showed that rehearsing their content dramatically boosts memory consolidation. Using MRI scanning, we measured patterns of brain activity while

  17. Neuralgic Amyotrophy Manifesting as Mimicking Posterior Interosseous Nerve Palsy

    PubMed Central

    Yang, Jin Seo; Kang, Suk Hyung; Choi, Eun Hi

    2015-01-01

    The upper trunk of the brachial plexus is the most common area affected by neuralgic amyotrophy (NA), and paresis of the shoulder girdle muscle is the most prevalent manifestation. Posterior interosseous nerve palsy is a rare presentation in patients with NA. It results in dropped finger on the affected side and may be misdiagnosed as entrapment syndrome or compressive neuropathy. We report an unusual case of NA manifested as PIN palsy and suggest that knowledge of clinical NA phenotypes is crucial for early diagnosis of peripheral nerve palsies. PMID:26713154

  18. Thoracic duct cyst of posterior mediastinum: a "challenging" differential diagnosis.

    PubMed

    Electra, Michalopoulou-Manoloutsiou; Evangelia, Athanasiou; Mattheos, Bobos; Dimitris, Hatzibougias I; Zarogoulidis, Paul; Tsavlis, Drosos; Kougioumtzi, Ioanna; Machairiotis, Nikolaos; Charalampidis, Chralampos; Fassiadis, Nikolaos; Mparmpetakis, Nikolaos; Pavlidis, Pavlos; Andreas, Mpakas; Stamatis, Arikas; Alexandros, Kolettas; Kosmas, Tsakiridis

    2016-05-01

    Thoracic duct cysts of the mediastinum are extremely rare entities and their pathogenesis still remains unknown. Imaging methods are not specific and show a cystic mass, however the real nature of the lesion is confirmed only with the help of histopathological examination after surgical excision. Here, we present a case of thoracic cyst in a 28-year-old female, lining in posterior lower mediastinum. The cyst was removed by video-assisted thoracic surgery (VATS) and the histopathological findings were that of thoracic duct cyst. Through this case, we propose an ideal surgical approach and diagnostic procedure.

  19. Outcomes of Short Segment Posterior Instrumentation in Unstable Thoracolumbar Fractures

    PubMed Central

    Gajjar, Sharvil H; Chaudhari, Nitin; Chaudhari, Vipul

    2016-01-01

    Introduction The spinal traumas are common and leading problem in orthopaedics practice. The individuals are at a risk of high energy trauma in modern era. Unstable thoracolumbar burst fractures are serious injuries of concern, if left untreated may result in marked morbidity and disability to the patient. Thoracolumbar is the second most common segment involved in the spinal cord following spinal injuries followed by cervical segment. The goal of treatment of any spinal injury is restoration of the patient to maximum possible function with disability free life. Aim To analyse the outcomes of unstable thoracolumbar burst fractures stabilized with short segment posterior instrumentation with transpedicular screws. Materials and Methods This prospective interventional study consisted of 32 patients with unstable thoracolumbar burst fractures carried out at Department of Orthopaedics, New Civil Hospital, Surat during Jan 2014 to Dec 2015. We stabilized the patients with unstable thoracolumbar spinal fractures with short segment posterior instrumentation by using the intermediate screw option in the fractured vertebra level as a method of augmentation. Patients were evaluated for maintenance of spinal correction and neurological improvement after short segment posterior instrumentation in unstable thoracolumbar burst fractures. Results The mean age for males was 35.57 ± 11.62 years and for females was 33.56 ± 11.2 years. The most common vertebra involved in the study group was T12 (31.25%). In the study, about 66% patients had a fall from height as the mode of injury, whereas 34% injuries were due to road traffic accident. In the study group, the mean regional angle observed during pre-operative stages was 16.0°±5.1°. There was a statistically significant (p<0.05) difference between pre-op and post-operative regional angles as well as anterior wedge angles. There was a statistically significant difference (p<0.05) in the vertebral height between pre-operative and

  20. Posterior Parietal Cortex: An Interface between Attention and Learning?

    PubMed Central

    Bucci, David J.

    2009-01-01

    The posterior parietal cortex (PPC) of rats has most recently been defined based on patterns of thalamic and cortical connectivity. The anatomical characteristics of this area suggest that it may be homologous to the PPC of primates and contribute to similar functions. This review summarizes evidence for and against a role for the rat PPC in attention and working memory and evaluates how the function of the rat PPC compares to that of primates on these dimensions. Theories of how the rat PPC contributes to behavior are presented, including the notion that PPC may serve as an interface between attention and learning. Finally, several avenues for future research are considered. PMID:18675370

  1. 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

  2. Prodromal Posterior Cortical Atrophy: Clinical, Neuropsychological and Radiological Correlation

    PubMed Central

    Chan, Lung Tat Andrew; Lynch, Whitney; De May, Mary; Horton, Jonathan C.; Miller, Bruce L.

    2015-01-01

    We present longitudinal clinical, cognitive and neuroimaging data from a 63-year-old woman who enrolled in research as a normal control and evolved posterior cortical atrophy (PCA) over five year follow-up. At baseline she reported only subtle difficulty driving and performed normally on cognitive tests, but already demonstrated atrophy in left visual association cortex. With follow-up she developed insidiously progressive visuospatial and visuoperceptual deficits, correlating with progressive atrophy in bilateral visual areas. Amyloid PET was positive. This case tracks the evolution of PCA from the prodromal stage, and illustrates challenges to early diagnosis as well as the utility of imaging biomarkers. PMID:24308559

  3. 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.

  4. 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

  5. Left hand tactile agnosia after posterior callosal lesion.

    PubMed

    Balsamo, Maddalena; Trojano, Luigi; Giamundo, Arcangelo; Grossi, Dario

    2008-09-01

    We report a patient with a hemorrhagic lesion encroaching upon the posterior third of the corpus callosum but sparing the splenium. She showed marked difficulties in recognizing objects and shapes perceived through her left hand, while she could appreciate elementary sensorial features of items tactually presented to the same hand flawlessly. This picture, corresponding to classical descriptions of unilateral associative tactile agnosia, was associated with finger agnosia of the left hand. This very unusual case report can be interpreted as an instance of disconnection syndrome, and allows a discussion of mechanisms involved in tactile object recognition.

  6. 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.

  7. 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 .

  8. Posterior fossa ruptured dermoid cyst presenting with hydrocephalus

    PubMed Central

    A. Wani, Abrar; Raswan, Uday S.; Malik, Nayil K.; Ramzan, Altaf U.

    2016-01-01

    Dermoid cysts are rare, benign lesions of embryological origin that represent 0.1-0.7% of all intracranial tumors. They are mainly located in the supra tentorial space, especially in the parasellar region. Their location in the posterior fossa remains uncommon. Rupture of intracranial dermoid cysts is a rare phenomenon. We present a case of dermoid cyst, which had ruptured into ventricular system. Computed Tomography and MRI revealed fat in the fourth ventricle, prepontine cistern, and cerebellomedullary cistern. Hydrocephalus was noted. We performed right ventriculo-peritoneal shunt on which patient improved and he continues to remain asymptomatic one year after. PMID:27744466

  9. 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

  10. Posterior maxillary segmental osteotomy for mandibular implants placement: case report.

    PubMed

    Meningaud, Jean-Paul; Pitak-Arnnop, Poramate; Corcos, Laurent; Bertrand, Jacques-Charles

    2006-11-01

    The loss of mandibular molars can result in a maxillary dentoalveolar extrusion, leading to an insufficient interarch space. In severe cases, this space must be regained before the prosthetic reconstruction of the opposite edentulous area. The posterior maxillary segmental osteotomy (PMSO) is a simple but precision technique to manage this problem; without which one can achieve a good surgical outcome but a poor final occlusion. The purpose of this paper was to present a case of PMSO for mandibular implant placement and to discuss the important steps.

  11. 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

  12. 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.

  13. Comparison of one-stage anteroposterior and posterior-alone hemivertebrae resection combined with posterior correction for hemivertebrae deformity

    PubMed Central

    Wang, Lei; Song, Yuemin; Pei, Fuxing; Liu, Limin; Liu, Hao; Kong, Qingquan; Li, Tao; Zeng, Jiancheng

    2011-01-01

    Background: The surgical technique of hemivertebrae excision varies from anteroposterior procedures to posterior-alone resections according to the experience and preference of surgeons. Both the approaches are reliable and give relatively good results. This study aims to evaluate and compare the clinical and radiological results of these two approaches for hemivertebrae resection. Materials and Methods: Sixty patients were retrospectively enrolled between 2006 and 2009. The subjects included 32 women and 28 men, with a mean age of 12.9 years (range: 5–24 years). Thirty patients who underwent one-stage anteroposterior hemivertebrae resection (the AP group) were followed for 38.5 months, and the other 30 patients who underwent posterior resection (the P group) were followed for 20.6 months. Clinical and radiological assessments were performed preoperatively, 1 week postoperatively, and at the final follow-up. The operation time, blood loss, degree of correction of the main curve/segmental curve/kyphosis, the average hospital stay, and complications were reviewed and compared between the two groups. Results: The mean operation time, blood loss, and hospital stay of the AP group and the P group were 451 min vs 248.5 min, 1290 ml vs 910 ml, and 21.93 days vs 18.97 days, respectively (P<.05). The average correction rate of the main curve/segmental curve/kyphosis of the AP group and the P group was 68.5% vs 66.2%, 71.5% vs 69.6%, and 57.4% vs 56.1%, respectively (P>.05). Overall complication rate was 6.7% in the AP group vs 10% in the P group (P>.05). Conclusion: Posterior hemivertebrael resection is a promising approach for congenital scoliosis in terms of relative safety, degree of correction achieved, reduced operative time and blood loss. PMID:22144739

  14. Posterior Cerebral Artery Insufficiency in Pediatric Moyamoya Disease

    PubMed Central

    Lee, Ji Yeoun; Kim, Seung-Ki; Phi, Ji Hoon

    2015-01-01

    The majority of clinical studies on moyamoya disease (MMD) have focused on anterior circulation. The disease involvement of posterior circulation in MMD, mainly in the posterior cerebral artery (PCA), has been mentioned since the early 1980s, and it has been repeatedly emphasized as one of the most important factors related to poor prognosis in MMD. However, its clinical features and outcome have only been elucidated during the last few years. In this review, the angiographic definition of PCA stenosis is summarized. The clinical features are elucidated as being either early-onset or delayed-onset, according to the time of PCA stenosis diagnosis in reference to the anterior circulation revascularization surgeries. The surgical strategy and hypothesis on the mechanism of PCA stenosis is also briefly mentioned. It appears that some MMD patients may show PCA stenosis during the early or late course of the disease and that the presenting symptoms may vary. Because the hemodynamic compromise caused by PCA stenosis may respond well to surgical treatment, clinicians should be aware of the condition, especially during follow-up of MMD patients. PMID:26180612

  15. 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

  16. 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

  17. 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.

  18. 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

  19. A PCR survey for posterior Hox genes in amphibians.

    PubMed

    Mannaert, An; Roelants, Kim; Bossuyt, Franky; Leyns, Luc

    2006-02-01

    Hox genes encode transcription factors that play a key role in specifying the body plan in metazoans and are therefore essential in explaining patterns of evolutionary diversity. As an ancient tetrapod group with diverse limb types, amphibians are important for understanding the origin and diversification of limbs in land vertebrates. We conducted a PCR survey in two species of each amphibian order to identify Hox-9 to Hox-13, known to function in limb development. Fifteen distinct posterior Hox genes and one retro-pseudogene were identified, and the former confirm the existence of four Hox clusters in each amphibian order. Some genes expected to occur in all tetrapods, based on the posterior Hox complement of mammals, fishes and coelacanth, were not recovered from our survey, and may have been lost. Hoxd-12 is absent in frogs and possibly other amphibians. Considering its function in autopodial development, the loss of this gene may be related to the absence of the fifth finger in frogs and salamanders.

  20. Latissimus Dorsi Transfer in Posterior Irreparable Rotator Cuff Tears

    PubMed Central

    Anastasopoulos, Panagiotis P.; Alexiadis, George; Spyridonos, Sarantis; Fandridis, Emmanouil

    2017-01-01

    Background: Massive rotator cuff tears pose a difficult and complex challenge even for the experienced surgeon; inability to repair these tears by conventional means designates them as irreparable, while management becomes quite taxing. Several operative options have been suggested for the management of such lesions with varying degrees of success, while it is imperative to match patient demands and expectations to the predicted outcome. Methods: Research articles are examined and key concepts are discussed, in order to provide an evidence based review of the available literature. The anatomy and pathomechanics along with the indications, contraindications and surgical techniques are reported. Results: Transfer of the Latissimus dorsi has been used with success to restore shoulder function in deficits of the posterior rotator cuff. Although it can be used in a variety of settings, the ideal patient for a Latissimus dorsi tendon transfer is a young and active individual, with no glenohumeral osteoarthritis that has a severe disability and weakness related to an irreparable posterior cuff tear. Conclusion: Tendon transfers have proved to be a successful treatment option in salvaging this difficult problem, providing pain relief and restoring shoulder function. Despite the excellent functional outcomes and pain suppression following operation, a variety of factors may affect the outcome; thus making indications and preoperative assessment a valuable component.

  1. Improvements in interpretation of posterior capsular opacification (PCO) images

    NASA Astrophysics Data System (ADS)

    Paplinski, Andrew P.; Boyce, James F.; Barman, Sarah A.

    2000-06-01

    We present further improvements to the methods of interpretation of the Posterior Capsular Opacification (PCO) images. These retro-illumination images of the back surface of the implanted lens are used to monitor the state of patient's vision after cataract operation. A common post-surgical complication is opacification of the posterior eye capsule caused by the growth of epithelial cells across the back surface of the capsule. Interpretation of the PCO images is based on their segmentation into transparent image areas and opaque areas, which are affected by the growth of epithelial cells and can be characterized by the increase in the image local variance. This assumption is valid in majority of cases. However, for different materials used for the implanted lenses it sometimes happens that the epithelial cells grow in a way characterized by low variance. In such a case segmentation gives a relatively big error. We describe an application of an anisotropic diffusion equation in a non-linear pre-processing of PCO images. The algorithm preserves the high-variance areas of PCO images and performs a low-pass filtering of small low- variance features. The algorithm maintains a mean value of the variance and guarantees existence of a stable solution and improves segmentation of the PCO images.

  2. Cortical connections of the rat lateral posterior thalamic nucleus.

    PubMed

    Kamishina, Hiroaki; Conte, William L; Patel, Sarika S; Tai, Rachel J; Corwin, James V; Reep, Roger L

    2009-04-06

    Spatial processing related to directed attention is thought to be mediated by a specific cortical-basal ganglia-thalamic-cortical network in the rat. Key components of this network are associative cortical areas medial agranular cortex (AGm) and posterior parietal cortex (PPC), dorsocentral striatum (DCS), and lateral posterior (LP) thalamic nucleus, all of which are interconnected. Previously, we found that thalamostriatal projections reaching DCS arise from separate populations of neurons of the mediorostral part of LP (LPMR). The far medial LPMR (fmLPMR) terminates in central DCS, a projection area of AGm, whereas central LPMR terminates in dorsal DCS, a projection area of PPC. This represents segregated regional convergence in DCS from different sources of thalamic and cortical inputs. In the present study, thalamocortical and corticothalamic projections arising from and terminating in LPMR and neighboring thalamic nuclei were studied by anterograde and retrograde tracing techniques in order to further understand the anatomical basis of this neural circuitry. A significant finding was that within LPMR, separate neuronal populations provide thalamic inputs to AGm or PPC and that these cortical areas project to separate regions in LPMR, from which they receive thalamic inputs. Other cortical areas adjacent to AGm or PPC also demonstrated reciprocal connections with LP or surrounding nuclei in a topographic manner. Our findings suggest that the cortical-basal ganglia-thalamic network mediating directed attention in the rat is formed by multiple loops, each having reciprocal connections that are organized in a precise and segregated topographical manner.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. The right posterior paravermis and the control of language interference

    PubMed Central

    Filippi, Roberto; Richardson, Fiona M.; Dick, Frederic; Leech, Robert; Green, David W.; Thomas, Michael S.C.; Price, Cathy J.

    2011-01-01

    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 where 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 where grey 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 most likely region to be excluded. PMID:21775616

  9. 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.

  10. 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.

  11. Reversible Switching of Cooperating Replicators

    NASA Astrophysics Data System (ADS)

    Urtel, Georg C.; Rind, Thomas; Braun, Dieter

    2017-02-01

    How can molecules with short lifetimes preserve their information over millions of years? For evolution to occur, information-carrying molecules have to replicate before they degrade. Our experiments reveal a robust, reversible cooperation mechanism in oligonucleotide replication. Two inherently slow replicating hairpin molecules can transfer their information to fast crossbreed replicators that outgrow the hairpins. The reverse is also possible. When one replication initiation site is missing, single hairpins reemerge from the crossbreed. With this mechanism, interacting replicators can switch between the hairpin and crossbreed mode, revealing a flexible adaptation to different boundary conditions.

  12. 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

  13. Marburg Virus Reverse Genetics Systems.

    PubMed

    Schmidt, Kristina Maria; Mühlberger, Elke

    2016-06-22

    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.

  14. Long-acting reversible contraception.

    PubMed

    Peck, Susan A

    2013-10-01

    Although short-acting reversible hormonal contraceptives, such as oral contraceptives and the contraceptive patch and vaginal ring, remain the most commonly used contraceptive methods in the United States, they are also associated with the highest failure rates. Long-acting reversible contraception (LARC) methods, such as intrauterine devices and contraceptive implants, offer high continuation rates and very low failure rates, and are safe for use in most women. The provision of LARC methods to adolescent, young adult and nulliparous women is a relatively new concept that offers an innovative option for these populations.

  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. Novel Classification of the Posterior Auricular Artery Based on Angiographical Appearance

    PubMed Central

    Tokugawa, Joji; Cho, Narisumi; Suzuki, Hiroharu; Sugiyama, Natsuki; Akiyama, Osamu; Nakao, Yasuaki; Yamamoto, Takuji

    2015-01-01

    Purpose To investigate the length variation of the posterior auricular artery and propose a novel classification of the posterior auricular artery based on angiographical appearance. Patients and Methods A series of 234 consecutive patients who had undergone conventional cerebral angiography was analyzed. The posterior auricular artery was examined on the lateral projection of the external carotid or common carotid arteriography. The posterior auricular artery was classified into four groups by length, using the external auditory canal and the top of the helix as radiographical landmarks. Our proposed classification is as follows: Type A, posterior auricular artery terminates between its origin and the center of the external auditory canal; Type B, posterior auricular artery terminates between the center of the external auditory canal and the top of the helix; Type C, posterior auricular artery terminates between the top of the helix and the vertex; and Type D, posterior auricular artery reaches up to the vertex. Results A total of 424 (right, 214; left, 210) posterior auricular arteries were analyzed in 111 men and 123 women aged 11 to 91 years (mean, 61.0 years) examined for aneurysms in 78 cases, occlusive vascular diseases in 56, intracranial hemorrhages in 41, tumors in 35, and others in 24. Types A, B, C, and D were found in 15.1%, 34.9%, 48.8%, and 1.2% of the patients, respectively. Conclusion A novel classification of the posterior auricular artery identifies four types based on its length on cerebral angiography. PMID:26030595

  17. 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.

  18. Nickel-hydrogen cell reversal characteristics

    NASA Technical Reports Server (NTRS)

    Lurie, Charles

    1994-01-01

    Nickel-hydrogen cell reversal characteristics are being studied as part of a TRW program directed towards development of a high current battery cell bypass switch. The following are discussed: cell bypass switch; nickel-hydrogen cell reversal characteristics; and nickel-hydrogen cell chemistry: discharge/reversal and overdischarge (reversal) with nickel and hydrogen precharge.

  19. 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.

  20. Response Reversals in Recognition Memory

    ERIC Educational Resources Information Center

    Van Zandt, Trisha; Maldonado-Molina, Mildred M.

    2004-01-01

    Using a dynamic sequential sampling model and a recently proposed model for confidence judgments in recognition memory (T. Van Zandt, 2000b), the authors examine the tendency for rememberers to reverse their responses after a primary decision. In 4 experiments, speeded "old"-"new" decisions were made under bias followed by a 2nd response', either…

  1. Reversible energy quenching and conservation

    NASA Astrophysics Data System (ADS)

    Fedorenko, S. G.; Burshtein, A. I.

    2010-05-01

    The kinetics of reversible energy transfer from photo-excited donors to energy acceptors is studied at arbitrary concentrations of both and any relationship between the decay-times of the reactants. The backward reaction of transfer products in a bulk is included in the consideration. Its contribution to delayed fluorescence, resulting from the energy conservation on the long-lived acceptors, is specified.

  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. 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...

  4. REVERSING THE SPIRAL TOWARD FUTILITY.

    ERIC Educational Resources Information Center

    PROCTOR, SAMUEL D.

    CONDITIONS THAT ENGENDER FUTILITY AND HOSTILITY AMONG NEGROES CAN BE REVERSED BY COMPETENT, DEDICATED TEACHERS. FACTORS LEADING TO NEGRO ATTITUDES OF DEFEAT ARE ANALYZED. EXPERIENCE OF REJECTION AND AWARENESS OF BEING DIFFERENT AND INFERIOR ARE AMONG THE FIRST REALIZATIONS OF THE NEGRO. FROM REJECTION GROWS FEAR OF WHITE INSTITUTIONS AND OF…

  5. Multiligament Injury of the Knee. First Intrarticular or Posterior

    PubMed Central

    Calderón, Nils

    2017-01-01

    Objectives: Show our experience about the multiligament injury of the knee. In the surgical technique it is most popular and recommended stabilized first all posterior and lateral (Ligament cruciate Posterior (LCP) and postero-lateral corner) if is a case. We show our experience stabilized first all intra-articular ACL and LCP. Methods: Prospective study and Case Series. The study includes, 45 cases in 15 years of experience. The patients have two or more ligaments with rupture, and associated lesions, like meniscus, cartilages, fractures, etc. 45 cases with a ACL rupture, 40 PCL, 7 posteromedial corner, 25 postero-lateral corner, 30 meniscus medial, 28 meniscus lateral, 1 vascular lesion, and 3 fibular nerve. In the surgical technique always use autograft. Prefer hamstrings, quadricipital tendon, contralateral hamstrings, BTB and sometimes peroneus brevis. We hope 1 or 2 weeks for the surgery. I never use pump, and use tourniquet for two hours. We start for the meniscus lesions and cartilage lesion and first reconstruction ligaments intra-articular. Finalized we open the tourniquet and stabilized the postero-lateral o posteromedial corner if is necessary. In the first cases we did a surgery in two times, but now we stabilized in one surgical time. Results: 3 to 6 days in the hospital 2 weeks immobilized and star rehabilitation with brace for more two weeks. Use crutches for 4-6 weeks. Worked in rehabilitation for a one year and star competition in one year. Complications: 1 case of amputation for vascular lesion, 9 arthrofibrosis, 2 medial instability, 1 lateral instability and1 LCP instability. One case needs a revision two years after the first surgery, for a new trauma in the work. All other cases had a new surgery for revision the residual instability. Conclusion: The multiligament injury of the knee it is not frequently, but every year I receive more cases, and more difficult. In the surgical technique have two options. The more recommended stabilized first

  6. 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

  7. Incidence of Recurrence in Posterior Circulation Childhood Arterial Ischemic Stroke

    PubMed Central

    Uohara, Michael Y.; Beslow, Lauren A.; Billinghurst, Lori; Jones, Brianna M.; Kessler, Sudha K.; Licht, Daniel J.; Ichord, Rebecca N.

    2017-01-01

    IMPORTANCE Childhood arterial ischemic stroke (CAIS) affects approximately 1.6 per 100 000 children per year, while stroke recurs in up to 20%of patients at 5 years. Factors determining the risk of recurrence are incompletely understood. OBJECTIVE To investigate the incidence of the recurrence of CAIS in the posterior and anterior circulations to determine if the risk differs between the 2 locations. DESIGN, SETTING, AND PARTICIPANTS A retrospective analysis of CAIS was conducted among children enrolled in a single-center prospective consecutive cohort at The Children’s Hospital of Philadelphia between January 1, 2006, and January 1, 2015. Children with confirmed CAIS occurring between 29 days and 17.99 years were evaluated for inclusion. Patients were excluded if infarcts were located in both the anterior and posterior distributions or if CAIS occurred as a complication of intracranial surgery or brain tumor. MAIN OUTCOMES AND MEASURES Stroke recurrence. RESULTS The study population included 107 patients (75 boys [70.1%] and 32 girls [29.9%]; median age at AIS, 7.7 years [interquartile range, 3.1–13.6 years]). Sixty-one children had anterior circulation CAIS (ACAIS) and 46 had posterior circulation CAIS (PCAIS). Median follow-up was 20.9 months (interquartile range, 8.7–40.4 months). For ACAIS, recurrence-free survival was 100% at 1 month and 96%(95%CI, 85%–99%) at 1 and 3 years. For PCAIS, recurrence-free survival was 88%(95%CI, 75%–95%) at 1 month and 81%(95% CI, 66%–90%) at 1 and 3 years. The hazard ratio for recurrence after PCAIS compared with ACAIS was 6.4 (95%CI, 1.4–29.8; P = .02) in univariable analysis and 5.3 (95%CI, 1.1–26.4; P = .04) after adjusting for sex and cervical dissection. CONCLUSIONS AND RELEVANCE We identified a subgroup of patients that comprise more than 80% of recurrences of CAIS. Three years after incident stroke, 19% of children with PCAIS had a recurrence compared with 4%of patients with ACAIS. Different mechanisms of

  8. 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

  9. Lesion analysis of cortical regions associated with the comprehension of Nonreversible and Reversible yes/no questions.

    PubMed

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

    2012-07-01

    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 associated with semantic and syntactic processing. In addition, we administered lexical tasks (i.e., Picture-Word Verification, Picture Naming) to help determine the extent to which deficits in sentence processing were related to deficits in lexical processing. We found that errors on the lexical tasks were associated with ischemia in posterior-temporal Brodmann Areas (BA 21, 22, 37) and inferior parietal regions (BA 39, 40). Nonreversible question comprehension was associated with volume of tissue dysfunction, while Reversible question comprehension was associated with posterior regions (BA 39, 40) as well as one anterior region (BA 6). We conclude that deficits in Nonreversible questions required extensive dysfunction that affected language processing across multiple levels, while Reversible question comprehension was associated with regions involved in semantics as well as working memory that indirectly influenced syntactic processing. Overall, this suggests that yes/no question comprehension relies on multiple regions and that the importance of certain regions increases in relation to semantic, phonological, and syntactic complexity.

  10. Acute Tetraplegia after Posterior Cervical Laminectomy for Chronic Myelopathy.

    PubMed

    Iorio, Justin A; Jakoi, Andre M; Wetzel, Franklin T

    2015-11-01

    Spinal cord injury (SCI) during revision surgery for persistent multilevel cervical myelopathy (MCM) after an initial anterior procedure is rare. However, the pathophysiology of MCM, even prior to surgery, is a risk-factor for neurological deterioration due to the development of a "sick cord", which reflects pathological changes in the spinal cord that lower the threshold for injury. We report a case of persistent MCM despite a three-level ACDF and corpectomy who developed an incomplete C6 tetraplegia during revision cervical laminectomy and posterior instrumentation. Intraoperative neuromonitoring signal-changes occurred in the absence of mechanical trauma. Postoperative MRI of the cervical spine demonstrated increased T2 hyperintensity and cord expansion at C3 and C4 compared to the pre-laminectomy MRI. The patient has not made improvements in her neurological status at 13 months postoperatively. The pathophysiology of MCM is discussed in addition to perioperative imaging, neuromonitoring, and use of steroids.

  11. [Posterior uveitis caused by highly malignant B cell lymphoma].

    PubMed

    Held, R; Eckardt, C; Brix, F; Feller, A C

    1989-01-01

    A diagnostic vitrectomy was performed on three patients with posterior uveitis of unknown origin and whose vitrous body was markedly affected. In all cases, cells of high-grade B-cell lymphoma (earlier referred to as reticulum cell sarcoma) were identified by cytological analysis of the specimen. In addition to the ocular findings, one of the three patients showed clinical and radiological evidence of a tumorous mass in the area of the right thalamus at the time of diagnosis. This was interpreted as a cerebral manifestation of the lymphoma. Initially, the other two patients did not show any cerebral involvement. One of them, however, developed clinical symptoms 9 months after diagnosis, which were radiologically verified as tumor infiltration of the cerebellum and the diencephalon. Under radiation therapy, the ocular findings disappeared within a few weeks.

  12. 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.

  13. Disrupting posterior cingulate connectivity disconnects consciousness from the external environment.

    PubMed

    Herbet, Guillaume; Lafargue, Gilles; de Champfleur, Nicolas Menjot; Moritz-Gasser, Sylvie; le Bars, Emmanuelle; Bonnetblanc, François; Duffau, Hugues

    2014-04-01

    Neurophysiological and neuroimaging studies including both patients with disorders of consciousness and healthy subjects with modified states of consciousness suggest a crucial role of the medial posteroparietal cortex in conscious information processing. However no direct neuropsychological evidence supports this hypothesis and studies including patients with restricted lesions of this brain region are almost non-existent. Using direct intraoperative electrostimulations, we showed in a rare patient that disrupting the subcortical connectivity of the left posterior cingulate cortex (PCC) reliably induced a breakdown in conscious experience. This acute phenomenon was mainly characterized by a transient behavioral unresponsiveness with loss of external connectedness. In all cases, when he regained consciousness, the patient described himself as in dream, outside the operating room. This finding suggests that functional integrity of the PPC connectivity is necessary for maintaining consciousness of external environment.

  14. The cracked-tooth syndrome and fractured posterior cusp.

    PubMed

    Snyder, D E

    1976-06-01

    1. Even from such a small sample as that reported in this study, it is evident that the fractured cusp and cracked-tooth syndrome are common problems. The large number of fractured cusps compared to the cracked-tooth syndrome suggests that some of the cases of fractured cusp could have been diagnosed earlier. 2. It is most important that dentists be aware of the cracked-tooth syndrome in order to relieve the patient's discomfort, prevent the possible eventual loss of the pulp or tooth, and avoid unnecessary and possibly damaging treatment for misdiagnosed facial pain. 3. Conservation of tooth structure in restorative procedures is most necessary in order to prevent the cracked-tooth syndrome or fractured posterior cusp.

  15. Synchronous anterior celiotomy and posterior drainage of pancreatic abscess.

    PubMed

    Berne, T V; Donovan, A J

    1981-05-01

    Pancreatic abscess has been characterized by a high rate of reoperation for persistent sepsis and by a high mortality. Nine patients with pancreatic abscess have undergone synchronous anterior celiotomy and posterior drainage following resection of the 12th rib. Pancreatic abscess was secondary to acute pancreatitis in seven of the cases. In two cases, the combined procedure was a secondary operation to treat abscess that developed following surgery for pancreatic trauma. All of these nine patients survived. One patient required reoperation for drainage of a left retrocolic abscess. A synchronous approach permits adequate exploration of the abdomen, provides the exposure necessary to remove necrotic tissue, and allows dependent drainage of the left subphrenic space without fear of splenic, pancreatic, or vascular injury.

  16. [Treatment of vulvar vestibulitis by posterior vestibulectomy. Twelve case reports].

    PubMed

    Berville, S; Moyal-Barracco, M; Paniel, B J

    1997-01-01

    Many patients with dyspareunia suffer from vulvar vestibulitis syndrome. When all conservative treatments have failed, surgery is attempted. We appreciated results and complications of this treatment. During 1993 and 1994, at the gynecological department of the intercommunal hospital of Creteil (France), twelve women suffering from this condition for longer than six months had undergone a posterior crescent-shaped vestibular excision followed by vaginal advancement. Three weeks after surgery, three partial dehiscences have been observed, which secondary healed. The average duration of follow-up was 8 months. The interview of the patients in January 1995 revealed: six patients obtained painless sexual intercourse, four patients improved significantly, one had no improvement and one complained of severe vulvar burning instead of dyspareunia. Our results are weighing against the initial enthusiasm to surgical treatment. Collaboration between gynecologists and psychologists to specify the indications and previous treatment of an associated vaginismus should be helpful for the treatment of these patients.

  17. 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

  18. 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

  19. 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

  20. Spontaneous Posterior Uterine Rupture in Twin-Twin Transfusion Syndrome

    PubMed Central

    Smid, Marcela C.; Waltner-Toews, Rebecca; Goodnight, William

    2015-01-01

    Background The maternal and fetal risks of uterine distension in rapidly progressive twin-twin transfusion syndrome (TTTS) in the setting of prior uterine scar are poorly characterized. Case We present the case of a 42-year-old woman, G4P1201, at 21 weeks gestation with stage-1 TTTS who developed a spontaneous posterior uterine rupture necessitating emergent laparotomy and delivery of previable fetuses, possibly due to prior uterine scar from a displaced intrauterine device. Conclusion TTTS may be a risk factor for uterine rupture, including uterine rupture in atypical anatomic locations. Prior unrecognized uterine scars, including perforations, may magnify the risk for atypical uterine rupture in the setting of excessive uterine distension. PMID:26929874

  1. Long-term consequences of posterior urethral valves.

    PubMed

    Lopez Pereira, Pedro; Martinez Urrutia, M J; Espinosa, L; Jaureguizar, E

    2013-10-01

    Posterior urethral valves (PUV) are the most common congenital cause of bladder outlet obstruction in infancy, and it is the effect of this obstruction on the bladder and the kidneys that will decide a patient's prognosis. With the improvements in diagnosis and treatments, what was previously a poor prognosis for boys with PUV has improved, and more patients will encounter the long-term sequelae of PUV during puberty and adulthood. In these patients the long-term prognosis in terms of renal and bladder function and fertility, as well as the risk of malignancy in those whose bladders were augmented with gastrointestinal segments, is still a matter of great concern and all of these topics will be discussed in this article.

  2. 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

  3. Posterior Vertebral Column Resection for VATER/VACTERL Associated Spinal Deformity: A Case Report

    PubMed Central

    Cunningham, Matthew E.; Charles, Gina

    2006-01-01

    The VATER/VACTERL association is a syndrome notable for congenital vertebral malformations, anal atresia, cardiovascular anomalies, tracheoesophageal fistula, esophageal atresia, and renal or limb malformations. Vertebral malformations may include the entire spectrum of congenital spinal deformities, including kyphosis, as was seen in this case. A 14-year-old girl presented to our institution with severe rigid sagittal deformity in the thoracolumbar spine that had recurred following three prior spinal fusion surgeries: the first posterior only, the second anterior and posterior, and the third a posterior only proximal extension. These surgeries were performed to control progressive kyphosis from a complex failure of segmentation that resulted in a 66° kyphosis from T11 to L3 by the time she was 9 years old. Our evaluation revealed solid arthrodesis from the most recent procedures with resultant sagittal imbalance, and surgical options to restore balance included anterior and posterior revision spinal fusion with osteotomies, multiple posterior extension osteotomies with circumferential spine fusion, and posterior vertebral column resection with circumferential spine fusion. She was advised that multiple posterior extension osteotomies would likely be insufficient to restore sagittal balance in the setting of solid arthrodesis from anterior and posterior surgery, and that the posterior-only vertebral column resection would provide results equivalent to revision anterior and posterior surgery, without the morbidity of the anterior approach. She successfully underwent posterior vertebrectomy and circumferential spinal fusion with instrumentation and is doing well 2 years postoperatively. Severe rigid sagittal deformity can be effectively managed with a posterior-only surgical approach, vertebrectomy, and circumferential spinal fusion with instrumentation. PMID:18751773

  4. Longterm remission of left posterior fascicular ventricular tachycardia due to mechanical trauma.

    PubMed

    Parizek, Petr; Popelka, Jiri; Haman, Ludek

    2010-08-01

    We present a case of a 28 year old woman with paroxysmal left posterior fascicular ventricular tachycardia (LPFVT). Ventricular tachycardia was not inducible after completing of left ventricle 3D reconstruction. Even though catheter ablation was not performed, no LPFVT recurrence has been documented during 60 months follow-up. We surmise that we caused mechanical trauma during the mapping of the posterior fascicle that damaged arrhythmogenic structures and subsequently led to long term remission of the left posterior fascicular ventricular tachycardia.

  5. The role of the posterior fusiform gyrus in reading.

    PubMed

    Devlin, Joseph T; Jamison, Helen L; Gonnerman, Laura M; Matthews, Paul M

    2006-06-01

    Studies of skilled reading [Price, C. J., & Mechelli, A. Reading and reading disturbance. Current Opinion in Neurobiology, 15, 231-238, 2005], its acquisition in children [Shaywitz, B. A., Shaywitz, S. E., Pugh, K. R., Mencl, W. E., Fulbright, R. K., Skudlarski, P., et al. Disruption of posterior brain systems for reading in children with developmental dyslexia. Biological Psychiatry, 52, 101-110, 2002; Turkeltaub, P. E., Gareau, L., Flowers, D. L., Zeffiro, T. A., & Eden, G. F. Development of neural mechanisms for reading. Nature Neuroscience, 6, 767-773, 2003], and its impairment in patients with pure alexia [Leff, A. P., Crewes, H., Plant, G. T., Scott, S. K., Kennard, C., & Wise, R. J. The functional anatomy of single word reading in patients with hemianopic and pure alexia. Brain, 124, 510-521, 2001] all highlight the importance of the left posterior fusiform cortex in visual word recognition. We used visual masked priming and functional magnetic resonance imaging to elucidate the specific functional contribution of this region to reading and found that (1) unlike words, repetition of pseudowords ("solst-solst") did not produce a neural priming effect in this region, (2) orthographically related words such as "corner-corn" did produce a neural priming effect, but (3) this orthographic priming effect was reduced when prime-target pairs were semantically related ("teacher-teach"). These findings conflict with the notion of stored visual word forms and instead suggest that this region acts as an interface between visual form information and higher order stimulus properties such as its associated sound and meaning. More importantly, this function is not specific to reading but is also engaged when processing any meaningful visual stimulus.

  6. Regional Variations in Mechanical Strain in the Posterior Human Sclera

    PubMed Central

    Fazio, Massimo A.; Grytz, Rafael; Bruno, Luigi; Girard, Michael J. A.; Gardiner, Stuart; Girkin, Christopher A.; Downs, J. Crawford

    2012-01-01

    Purpose. The goal of this study was to establish sectorial and regional variability in the mechanical strain of peripapillary and mid-peripheral sclera in normal eyes from elderly human donors. Methods. Ten pairs of normal eyes from human donors aged 57 to 90 years old were mechanically inflation-tested within 48 hours post mortem. The intact posterior scleral shells were pressurized from 5 to 45 mm Hg while the full-field three-dimensional displacements of the scleral surface were measured using laser speckle interferometry. The displacement field was fit to continuous and differentiable analytical functions, from which the full strain tensor of the outer scleral surface was calculated. Mean maximum principal (tensile) strain was computed for eight circumferential sectors (45° wide) within the peripapillary and mid-peripheral regions surrounding the optic nerve head (ONH). Results. Overall, the peripapillary sclera exhibited significantly higher tensile strain (1.2%) than mid-peripheral sclera (0.95%) for a 40 mm Hg IOP elevation (P < 0.00001). In the peripapillary region, the inferotemporal sector exhibited the highest tensile strain (1.45%) while the superior sector had the lowest (1.19%; P < 0.00001). Mid-peripheral scleral strains were lower but exhibited a similar sectorial pattern. Conclusions. Human posterior sclera exhibits complex regional mechanical behavior in response to acute IOP elevations from 5 to 45 mm Hg. Results indicate 1) the peripapillary sclera is subjected to significantly higher tensile strain than the adjacent mid-peripheral sclera, and 2) strains are significantly higher in the temporal and inferior quadrants of the peripapillary sclera, which may contribute to the increased prevalence of glaucomatous damage associated with these regions of the ONH. PMID:22700704

  7. Magnetic resonance properties of hydrogen: imaging the posterior fossa

    SciTech Connect

    Young, I.R.; Burl, M.; Clarke, G.J.

    1981-11-01

    Posterior fossa scans were performed on five healthy volunteers using a nuclear magnetic resonance (NMR) machine constructed by Thorn-EMI Ltd. Three different NMR scanning sequences were used. In the first, a type of saturation-recovery technique was used to produce images strongly dependent on the density of hydrogen nuclei, but with some dependence on the spin-lattice relaxation time (T/sub 1/). In the second, an inversion-recovery technique was used to produce images with a stronger dependence on the spin-lattice relaxation time. In the third, a spin-echo technique was used to obtain images with a dependence on the spin-spin relaxation time (T/sub 2/). All three types of NMR image were unaffected by bone artifact. Visualization of brain adjacent to the skull base was obtained without loss of detail due to partial-volume effect from bone. The saturation-recovery images highlighted arteries and veins that were clearly visible without the use of contrast agents. The inversion-recovery images showed remarkable gray-white matter differentiation enabling internal structure to be seen within the brainstem and cerebellum. The trigeminal nerve and ganglion were also seen outside the brain. Experience with the spin-echo technique is limited, but the images at the base of the brain show considerable soft-tissue detail. The NMR images of the posterior fossa in this study were comparable in quality to those obtained from a new rotate-rotate x-ray computed tomography machine and were superior in several respects.

  8. Sex Differentiation in Meloidogyne incognita and Anatomical Evidence of Sex Reversal

    PubMed Central

    Papadopoulou, Joanna; Traintaphyllou, A. C.

    1982-01-01

    Sex differentiation was studied by examining the cellular structure of gonad primordia extracted from second-stage juveniles developing under different environmental conditions. In female jnveniles, divisions of the two somatic cells of the primordium occurred in mid-sccond stage and resulted in 12 cells. Two of them were differentiated as cap cells, two occupied the anterior central and eight the posterior central part of the V-shaped primordium. The two germinal cells divided at the 6-8 somatic-cell stage of the primordium; i.e., earlier than in any other plant-parasitic nematode. In male juveniles of similar developmental stage, divisions of somatic cells resulted in 10 cells: one cap cell at the posterior tip and nine cells at the anterior part of the rod-shaped primordium. Germinal cells divided at the 6-8 sontatic-cell stage. On the basis of gonad anatomy it was concluded that some female juveniles undergo sex reversal and proceed with further development as males. The degree of expression of intersexual features depends on the period at which sex reversal occurs. Sex reversal at an early period gives rise to males with one testis, almost indistinguishable front true males. Sex reversal at mid-second stage involves degeneration of the nucleus of one of the cap cells resulting in males with an atrophied testis and a well-developed testis. More delayed sex reversal results in males with two testes of approximately equal size. To explain these patterns of development, it is assumed that sex differentiation is hormonally controlled and that the environment influences hormonal balance by affecting gene expression. PMID:19295752

  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. 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.

  11. Determining the zone of reflection for posterior corneal surface comparison phakometry.

    PubMed

    Carkeet, Andrew

    2009-01-01

    Although comparison phakometry has been used by a number of studies to measure posterior corneal shape, these studies have not calculated the size of the posterior corneal zones of reflection they assessed. This paper develops paraxial equations for calculating posterior corneal zones of reflection, based on standard keratometry equations and equivalent mirror theory. For targets used in previous studies, posterior corneal reflection zone sizes were calculated using paraxial equations and using exact ray tracing, assuming spherical and aspheric corneal surfaces. Paraxial methods and exact ray tracing methods give similar estimates for reflection zone sizes less than 2 mm, but for larger zone sizes ray tracing methods should be used.

  12. Reconstruction of posterior interosseous nerve injury following biceps tendon repair: case report and cadaveric study.

    PubMed

    Mokhtee, David B; Brown, Justin M; Mackinnon, Susan E; Tung, Thomas H

    2009-06-01

    Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the terminal branches of the posterior interosseous nerve that makes this reconstruction possible. Finally, we advocate consideration for identification of the posterior interosseous nerve prior to reattachment of the biceps tendon to the radial tuberosity.

  13. Posterior capsule opacification and neovascularization treated with intravitreal bevacizumab and Nd:YAG capsulotomy

    PubMed Central

    Sánchez-Castro, Grimelda Yuriana; Hitos-Fájer, Alejandra; Mendoza-Schuster, Erick; Velez-Montoya, Raul; Velasco-Barona, Cecilio Francisco

    2008-01-01

    We reported a 75-year-old diabetic man, who developed opacification and neovascularization of the posterior capsule after extracapsular cataract extraction and posterior chamber intraocular lens implantation. The patient was treated with two injections of 2.5 mg of intravitreal bevacizumab. The treatment produced an important regression of the posterior capsular new vessels, allowing us to perform a successful Nd:YAG capsulotomy, clearing the visual axis and improving the visualization of the posterior pole. Even though, best corrected visual acuity was 20/200 due to diabetic macular edema. PMID:19668770

  14. Probing the interaction of the ipsilateral posterior parietal cortex with the premotor cortex using a novel transcranial magnetic stimulation technique

    PubMed Central

    Shields, Jessica; Park, Jung E.; Srivanitchapoom, Prachaya; Paine, Rainer; Thirugnanasambandam, Nivethida; Kukke, Sahana N.; Hallett, Mark

    2015-01-01

    Objective Functional imaging studies have shown that control of planned movement involves a distributed network that involves the premotor (PMv) and posterior parietal cortices (PPC). Similarly, anatomical studies show that these regions are densely interconnected via white matter tracts. We therefore hypothesized that the PPC influence over the motor cortex is partly via a connection with the PMv. Methods Using a novel three-pulse ipsilateral transcranial magnetic stimulation technique, we preconditioned the PPC (80%RMT) at ISIs from 4–15ms prior to stimulating the PMv and M1 at ISIs of 4 and 6ms. Results As previously shown, PMv-M1 paired-pulse stimulation resulted in inhibition of the MEP (90% RMT, 4–6ms) and PPC-M1 paired-pulse stimulation resulted in facilitation of the MEP (90% RMT, 4–8ms). PPC-M1 paired-pulse stimulation at 80%RMT preconditioning had no effect on M1. PPC-PMv-M1 stimulation resulted in reversal of inhibition observed with PMv-M1 stimulation at ISIs ranging from 6–15ms. Conclusions The reversal of inhibition observed with PPC-PMv-M1 stimulation suggests that the parietal connection to the PMv plays a role in the modulation of M1. Significance This is the first study to stimulate three intrahemispheric regions in order to test a disynaptic connection with M1. The described network may be important in a variety of movement disorders. PMID:26253032

  15. Reversion phenomena of Cu-Cr alloys

    NASA Technical Reports Server (NTRS)

    Nishikawa, S.; Nagata, K.; Kobayashi, S.

    1985-01-01

    Cu-Cr alloys which were given various aging and reversion treatments were investigated in terms of electrical resistivity and hardness. Transmission electron microscopy was one technique employed. Some results obtained are as follows: the increment of electrical resistivity after the reversion at a constant temperature decreases as the aging temperature rises. In a constant aging condition, the increment of electrical resistivity after the reversion increases, and the time required for a maximum reversion becomes shorter as the reversion temperature rises. The reversion phenomena can be repeated, but its amount decreases rapidly by repetition. At first, the amount of reversion increases with aging time and reaches its maximum, and then tends to decrease again. Hardness changes by the reversion are very small, but the hardness tends to soften slightly. Any changes in transmission electron micrographs by the reversion treatment cannot be detected.

  16. Diabetes insipidus and Langerhans cell histiocytosis: a case report of reversibility with 2-chlorodeoxyadenosine.

    PubMed

    Ottaviano, Fabio; Finlay, Jonathan L

    2003-07-01

    Diabetes insipidus (DI) is the most common manifestation of central nervous system involvement in Langerhans cell histiocytosis (LCH). Patients with LCH involving the head and neck region are reported to have about a 40% lifetime chance of developing DI. The clinical and biochemical diagnosis of DI is sometimes supported by the absence of the posterior pituitary bright signal on magnetic resonance images. Cladribine (2-chlorodeoxyadenosine, 2-CDA) has been reported as an active drug in children and adults with relapsed or refractory LCH. The authors report the successful reversal of DI in a 3-year-old child with established LCH using 2-CDA.

  17. Reversing the Brazil Nut Effect

    NASA Astrophysics Data System (ADS)

    Ludewig, F.; Vandewalle, N.

    2005-12-01

    We propose a lattice model for studying the Brazil Nut Effect (BNE), i.e. the phase segregation occuring when a granular material is vertically shaked. The model considers the tap intensity and the mobility μ of the grains as the main physical parameters. Different mobilities for different grain species lead to segregation (BNE) patterns, reverse segregation (RBNE) patterns, “sandwhich" layered structures or vertical domains. A phase diagram (decompaction χ, mobility difference between both species Δ μ) is obtained in which the different phases are emphasized. In a narrow region of the diagram, different phases coexist. It is shown that the BNE segregation could be reversed by increasing the tap intensity or the characteristics of the grains. Numerical results are compared with earlier experimental works.

  18. [Pneumothorax after "reversed" bungee jump].

    PubMed

    Pedersen, M N; Jensen, B N

    1999-10-04

    We here present a case of pneumothorax in a 24 year-old previously healthy man who had performed an uncomplicated "reversed" bungee jump a few hours before. A high resolution CT scan of the thorax taken three weeks later was normal. The high energy produced during a "reversed" bungee jump, up to 7-8 g corresponds to the threshold value for NASA astronauts, and can cause injuries in healthy persons. In this case we believe that there is a correlation between the pneumothorax and the high energy jump. Bungee jumping is a very popular amusement, millions of jumps have been carried out since 1979, when the sport was introduced. No register and therefore no ratio of risk exists.

  19. Molecular Simulation of Reverse Micelles

    NASA Astrophysics Data System (ADS)

    Chowdhary, Janamejaya; Ladanyi, Branka

    2009-03-01

    Reverse micelles (RM) are surfactant assemblies containing a nanosized water pool dissolved in a hydrophobic solvent. Understanding their properties is crucial for insight into the effect of confinement on aqueous structure, dynamics as well as physical processes associated with solutes in confinement. We perform molecular dynamics simulations for the RM formed by the surfactant Aerosol-OT (AOT) in isooctane (2,2,4-trimethyl pentane) in order to study the effect of reverse micelle size on the aqueous phase. The structure of the RM is quantified in terms of the radial and pair density distributions. Dynamics are studied in terms of the mean squared displacements and various orientational time correlation functions in different parts of the RM so as to understand the effect of proximity to the interface on aqueous dynamics. Shape fluctuations of the RM are also analyzed.

  20. Reverse osmosis water purification system

    NASA Technical Reports Server (NTRS)

    Ahlstrom, H. G.; Hames, P. S.; Menninger, F. J.

    1986-01-01

    A reverse osmosis water purification system, which uses a programmable controller (PC) as the control system, was designed and built to maintain the cleanliness and level of water for various systems of a 64-m antenna. The installation operates with other equipment of the antenna at the Goldstone Deep Space Communication Complex. The reverse osmosis system was designed to be fully automatic; with the PC, many complex sequential and timed logic networks were easily implemented and are modified. The PC monitors water levels, pressures, flows, control panel requests, and set points on analog meters; with this information various processes are initiated, monitored, modified, halted, or eliminated as required by the equipment being supplied pure water.