Diffuse Enhancement Research Articles

Patient with AIP gene mutation presenting with pituitary adenomatosis

Abstract Introduction/Objective Familial isolated pituitary adenoma (FIAP) is frequently associated with germline mutation in the AIP gene. Clinically, it is characterized by the occurrence of isolated pituitary adenoma in 2 or more members of a family. In this case report, we describe a patient who presented with a pituitary adenoma and concurrent disseminated leptomeningeal adenomatosis. Methods/Case Report A 17-year-old female presented with amenorrhea and visual impairment. Brain MRI showed a 2.6 x 2.8 x 2.4 cm mass in the sella turcica extending to the suprasellar region. Multiple separate smaller (5-7 mm) masses in the leptomeninges of the anterior and middle cranial fossa, and small enhancing masses within the internal auditory canals bilaterally were also seen. She underwent craniotomy for resection of the pituitary tumor which was diagnosed pathologically as sparsely granulated somatotroph adenoma with co-expression of human growth hormone and prolactin. Postoperatively, she was found to have persistent hormone imbalance for which she received proton beam therapy. Genetic testing revealed mutations in the AIP gene. No mutations were detected in NF2, MEN1, and CDKN1B. At age 21, radiologic follow-up revealed recurrent pituitary adenoma, for which she underwent trans- sphenoidal resection, revealing the same histopathologic diagnosis. At age 22, MRI showed diffuse nodular enhancement throughout the subarachnoid spaces, most pronounced within the Sylvian fissures. Cytologic examination of cerebrospinal fluid (CSF) showed several loose aggregates of neuroendocrine cells, positive for synaptophysin by immunocytochemistry, consistent with the diagnosis with dissemination of pituitary adenoma cells in the leptomeninges. Results (if a Case Study enter NA) N/A Conclusion In all 136 previously reported cases, leptomeningeal dissemination of pituitary adenoma has been exclusively described in post-surgical settings or after pituitary apoplexy. To our knowledge, this is the first case of disseminated pituitary adenomatosis noted at initial clinical presentation

Optimization of the structure and cathode operating parameters of a serpentine PEMFC with longitudinal vortex generators by response surface method

An improved method based on a concept for enhancing heat and mass transfer based on longitudinal vortex system is proposed for optimizing the performance and water-thermal management of proton exchange membrane fuel cells (PEMFCs). A certain number of rectangular plates are added to the cathode channel of the serpentine plate to create the longitudinal vortex to enhance the diffusion of fuel gas, the discharge of water, and temperature distribution uniformity of the fuel cell. A series of numerical studies are conducted employing the response surface method to evaluate the effect of cathode operating parameters on the efficiency and power density of the fuel cell system. The results obviously suggest that the installation of twenty groups of Longitudinal vortex generators(LVGs) in the first four straight flow channels can enhance the mean current density by 5.02 % compared with the condition without LVGs. Meanwhile, LVGs in the cathode flow channel close to the inlet can also enhance the distribution uniformity of membrane temperature by 11.38 %, which can contribute to the diffusion enhancement of oxygen by 36.94 % at the cathode and the improvement of water distribution uniformity by 10.87 %. The main reason for this phenomenon is that the rectangular-plate longitudinal vortex generator can increase the local turbulence intensity of the fuel gas in the cathode channel; therefore, more fuel gas can be transported from the channel to the diffusion layer, leading to a greater current density, in addition to the fact that the generated longitudinal vortex system can assist the exiting of the generated water from the channel. In addition to these, increasing pressure or reducing temperature or relative humidity can enhance power density, while reducing relative humidity is beneficial for improving system efficiency.

Enhanced diffusion of tracer particles in nonreciprocal mixtures.

We study the diffusivity of a tagged particle in a binary mixture of Brownian particles with nonreciprocal interactions. Numerical simulations reveal that, for a broad class of interaction potentials, nonreciprocity can significantly increase the long-time diffusion coefficient of tracer particles and that this diffusion enhancement is associated with a breakdown of the Einstein relation. These observations are quantified and confirmed via two different and complementary analytical approaches: (i) a linearized stochastic density field theory, which is particularly accurate in the limit of soft interactions, and (ii) a reduced two-body description, which is exact at leading order in the density of particles. The latter reveals that diffusion enhancement can be attributed to the formation of transiently propelled dimers of particles, whose cohesion and speed are controlled by the nonreciprocal interactions.

Strain-induced clustering in Al alloys

Solute clusters represent the start of decomposition during aging of aluminum alloys and can generate strengthening while keeping the strain hardening high in comparison with shearable precipitates. In this study, clusters in a pre-aged AlMgSiCu 6xxx-series and a recently developed AlMgZnCu crossover alloy were investigated by atom probe tomography (APT) and tensile testing before and after straining. Pre-aging was performed at 100 °C and 60 °C respectively, and a tensile strain of 5% was applied. The key feature detected was the formation of clusters during plastic deformation, referred to here as “strain-induced clustering”. It is explained based on diffusion enhancement by the strain-induced formation of excess vacancies during tensile testing, and evaluated by means of a simple modeling approach. In addition to the significant intrinsic contribution of clusters to strain hardening via dislocations, strain-induced clustering adds a hypothetical non-dislocation-based component to strain hardening.

NCOG-28. RECURRENCE OF PLEOMORPHIC XANTHOASTROCYTOMA PRESENTING WITH DIFFUSE LEPTOMENINGEAL SPREAD

Abstract Pleomorphic xanthoastrocytomas (PXAs) are rare primary brain tumors that mainly affect children and young adults. We report a case of recurrent PXA in an adult and review the literature. To our knowledge, this is the first adult report highlighting clinical, CSF, and imaging findings of recurrent PXA with leptomeningeal spread. A 60-year-old woman presented with a 2-month history of fluctuating mental status, aphasia, low-back pain, progressive paraparesis, and urinary retention. She was previously diagnosed with a left temporal PXA 17 years prior and underwent gross total resection with no evidence of tumor recurrence for the next several years. Approximately 10 months prior to her current presentation, she was found to have radiographic recurrence of the left temporal PXA. She underwent gross total resection, with final pathology revealing anaplastic transformation, WHO grade 3, BRAF V600E mutation positive. She next underwent photon radiotherapy, and chemotherapy with temozolomide. She had good clinical and radiographic response to treatment for 8 months prior to developing her current symptomatology. MRI of the brain and spine showed local recurrence with new diffuse contrast enhancement of the spinal cord and nerve roots. Cerebrospinal fluid (CSF) analysis showed a total nucleated cell count of 10/mcL, protein >1250 mg/dL, glucose < 20 mg/dL, and xanthochromia. CSF cytology was positive for malignant cells consistent with PXA. Although PXA is often associated with a favorable prognosis, recurrence with anaplastic transformation can be associated with dissemination throughout the nervous system and worse outcomes. Despite the rarity of such cases, clinicians should remain vigilant, especially when anaplastic transformation occurs. Early detection of leptomeningeal involvement through thorough CSF analysis and appropriate imaging can facilitate prompt intervention and potentially improve patient outcomes.

RADT-33. ANALYSIS OF PATIENTS DIAGNOSED WITH ATYPICAL TERATOID RHABDOID TUMOR OF BRAIN AT TERTIARY CARE CENTER

Abstract Atypical Teratoid Rhabdoid Tumor (ATRT) of brain is highly malignant neoplasm with incidence of 1-2% among all pediatric CNS tumors characterized by mutations and subsequent inactivation of SMARCB1 (INI1, hSNF5) gene with dismal prognosis of about 6-18 months. On retrospective analysis of patients between 2010-2021 from Medical Record Department, only five cases of ATRT brain were retrieved. All patients were of pediatric age group (6 yr/F, 2yr/M, 6yr/F, 4yr/F, and 1yr/M – Median 4 yrs). On radiological findings, in four patients lesion was primarily in brain and in one patient with diffuse leptomeningeal enhancement. Three patients underwent craniotomy and gross total excision, and, in 2 patients only biopsy was done. In molecular analysis immunohistochemistry (IHC) markers were as follows. In all patients Vimentin and Synaptophysin were positive. EMA was positive in 3 patients, GPAP was positive in 3 patients, CD99 was positive in 2 patients, AE1 was positive in 2 patients. A specific marker for ATRT (INI1 loss) was seen in 3 patients. In other patients INI1 assessment could not be done. In two patients CSF cytology was negative, and, in all patients bone marrow examination was normal. One patient (4yr/F) received local radiotherapy with concurrent Vincristine based chemotherapy and lost to follow up (after 1 year of treatment). One patient (6yr/F) received vincristine based chemotherapy and local palliative radiotherapy and expired (after 1 month of treatment). One patient (6yr/F) received St Jude HR/IRS III protocol chemotherapy and craniospinal irradiation (CSI) and is still on follow up (total follow up period – 9 years). Two patients did not take any kind of treatment in whom one patient expired, another lost to follow up. Looking at rarity of tumors and with the review of literature, multiagent chemotherapy and Craniospinal irradiation seems to be promising approach for treatment of ATRT brain.

Seizure as the first symptom of cavernous sinus dural arteriovenous fistula: A case report and literature review

Cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication associated with a variety of clinical manifestations. The previous literature has rarely reported the occurrence of CS-DAVF with seizures and cerebral hemorrhage, signaling the need for more case reports and literature review in this area. A 62-year-old Chinese female presented with a paroxysmal loss of consciousness, accompanied with involuntary eye movement to the left, chewing issues, salivation at the right corner of the mouth, and bit tongue. The brain computed tomography revealed that the left temporal lobe was hemorrhagic. Brain scan and contrast-enhanced magnetic resonance imaging showed diffuse meningeal enhancement and lesions in the left frontoparietal temporal lobe, insular lobe, and hippocampal head region. Electroencephalography demonstrated continuous emission of spike and slow waves in the left hemisphere. With the aid of digital subtraction angiography, the patient was confirmed with a diagnosis of CS-DAVF draining into the ipsilateral cavernous sinus, intercavernous sinus, contralateral cavernous sinus, left superior ophthalmic vein, left lateral fissure vein, and left pterygoid venous plexus. The fistula was closed with interventional embolization through the femoral vein, and immediate angiography showed complete resolution of CS-DAVF after operation. The patient did not manifest any post-operative complications. This case highlights that the prevention of epilepsy, cerebral hemorrhage, and other serious complications is extremely important for good prognosis, especially in some patients presenting with serious clinical symptoms. It also sheds light on the necessity to consider the diagnosis of CS-DAVF if seizures, although extremely rare, are present.

Abstract 18975: First Reported Case of SLE Associated Recurrent Pericarditis Treated With Rilonacept

Description of case: A 42 year old female presented with a 1 month history of exertional dyspnea and intermittent pleuritic chest pain. She had a 12-year history of systemic lupus erythematosus (SLE) and non-specific interstitial pneumonitis being managed with mycophenolate mofetil. Labs showed an ESR of 76 mm/hr and CRP of 5.5 mg/dL. CT chest ruled out pulmonary embolism but showed a moderate pericardial effusion, also seen on an echocardiogram. A cardiac MRI (cMRI) showed moderate diffuse circumferential pericardial enhancement. She was diagnosed with lupus pericarditis and initially treated with ibuprofen, colchicine, prednisone, and hydroxychloroquine; however, continued to have persistent symptoms over the next few months. Repeat cMRI showed a transition to effusive constrictive physiology. She was offered pericardiectomy but following shared decision making and multi-disciplinary discussion, she was started on Rilonacept. She experienced significant and sustained relief in symptoms, improvement in inflammatory markers and reduction of pericardial enhancement on cMRI. Discussion To the best of our knowledge, this is the first case of Rilonacept used to successfully treat recurrent pericarditis from SLE. Recurrence in chronic idiopathic pericarditis is thought to be driven by the innate immune system and Interleukin-1 (IL-1), while in autoimmune diseases, it is mediated by the adaptive immune system and Type 1 Interferon, which is associated with a poorer prognosis. The RHAPSODY and AIRTRIP trials demonstrating efficacy of IL-1 blockers in recurrent pericarditis excluded patients with autoimmune diseases. Use of IL-1 blockers to treat Lupus pericarditis has only been reported in 2 cases using Anakinra. Our patient’s positive response to Rilonacept suggests the presence of additional target pathways in autoimmune diseases that may mediate pericarditis recurrence. Future prospective studies are needed to elucidate this further.

Supratentorial extra-axial anaplastic ependymoma: a rare case report.

Ependymomas are central nervous system tumors arising from the ependymal lining of the ventricle and spinal cord. Supratentorial extra-axial ependymomas are very rare, most commonly affecting the pediatric population and rarely in adults. The authors report a case of a 71-year-old female with a headache and blurred vision. An MRI scan revealed a lesion at the parafalcine region of the occipital lobe. A parieto-occipital craniotomy was performed. When the dura was opened during the operation, the extra-axially located, well-circumscribed, dirty yellow-white tumor dissected from the surrounding tissue was excised entirely by microdissection. Histopathological examination revealed supratentorial extra-axial anaplastic ependymoma. The patient received postoperative radiation therapy (54 Gray over 30 fractions). No recurrence of the tumor was observed during the 4-year follow-up. Supratentorial ependymomas at the extra-axial region are uncommon; extra-axial anaplastic ependymoma and meningiomas have similar radiological findings, such as a dural tail, subarachnoid plane, and diffuse enhancement after contrast injection. This close similarity might cause misdiagnoses. Total surgical resection was followed by adjuvant radiotherapy and close follow-up in the gold standard of the treatment. The authors report a rare case of anaplastic ependymomas located at the extra-axial region. Anaplastic tumors are prone to recurrence despite total resection and radiation therapy; hence, a close follow-up is warranted.

Bickerstaff’s brainstem encephalitis: a rare case of neurologic complication in Ulcerative Colitis

Bickerstaff’s brainstem encephalitis is a rare autoimmune disorder that presents with ataxia, ophthalmoplegia, disturbance of consciousness and quadriplegia. A 45-year-old man with a history of ulcerative colitis (UC) taking mesalazine (5-aminosalicylic acid) visited the emergency room presenting with ataxia, ophthalmoplegia and a progressively worsening cognitive impairment. Cerebrospinal fluid analysis showed mild elevation in protein and white blood cell count and increased intracranial pressure. Anti-GQ1b autoantibodies were found positive in the patient’s serum and contrast-enhanced brain magnetic resonance imaging showed diffuse leptomeningeal enhancement and pontine lesions. Based on these findings and the patient’s clinical course and history, he was diagnosed with Bickerstaff’s brainstem encephalitis. Mesalazine was discontinued and high-dose steroid pulse therapy was started, followed by intravenous immunoglobulin, which resulted in gradual improvement of the neurologic symptoms. When an ulcerative colitis patient presents with progressive cognitive impairment, quadriplegia and disturbance of consciousness and gait, Bickerstaff brainstem encephalitis should be considered in the differential diagnosis and prompt immunotherapy may lead to favorable prognosis.

Likelihood of Discovering a CSF Leak Based on Intracranial MRI Findings in Patients without a Spinal Longitudinal Extradural Collection: A New Probabilistic Scoring System.

The likelihood of discovering a CSF leak can be determined by assessing intracranial abnormalities. However, the Dobrocky scoring system, which is used to determine this likelihood, did not incorporate patients with CSF-venous fistulas. This study sought to create a new probabilistic scoring system applicable to patients without a spinal longitudinal extradural collection. A retrospective review was completed of patients with suspected spontaneous intracranial hypotension who underwent brain MR imaging followed by digital subtraction myelography with same-day CT myelography. Patients with and without leaks found on digital subtraction myelography were included. MRIs were assessed for numerous reported stigmata of spontaneous intracranial hypotension and were compared between cohorts. One hundred seventy-four patients were included; 113 (64.9%) were women (average age, 52.0 [SD, 14.3] years). A CSF leak was found in 98 (56.3%) patients, nearly all of which (93.9%) were CSF-venous fistulas. Diffuse dural enhancement, internal auditory canals dural enhancement, non-Chiari cerebellar descent, pituitary engorgement, brain sag, dural venous sinus engorgement, and decreased suprasellar cistern size were associated with a CSF leak. A probabilistic scoring system was made in which a single point value was assigned to each of those findings: 0-2 considered low probability and ≥3 considered intermediate-to-high probability of a CSF leak. This study offers a new probabilistic scoring system for evaluating the likelihood of discovering a CSF leak on the basis of intracranial MR imaging findings, though the new system is not superior to that of the Dobrocky method for predicting the presence of CSF leaks.

Diffusely invasive supratentorial rosette-forming glioneuronal tumor: illustrative case.

Rosette-forming glioneuronal tumors (RGNTs) are rare tumors composed of mixed glial and neurocytic components. Most lesions are confined to the posterior fossa, especially in the region of the fourth ventricle, in young adults. In few instances, diffuse involvement of the supratentorial region is identified, thereby creating significant challenges in diagnosis, surgical intervention, and prognostication. The authors present a 23-year-old female with chronic headaches, papilledema, and hydrocephalus who underwent radiographic evaluation revealing obstructive hydrocephalus and diffuse supratentorial enhancing and nonenhancing cystic and nodular lesions. The patient underwent a right frontal craniotomy and septostomy. An exophytic nonenhancing right frontal horn lesion was resected, and an enhancing third-ventricular lesion was biopsied. Final pathology of both of the lesions sampled was consistent with RGNT. Next-generation sequencing demonstrated tumor alterations in the FGFR-1 and PIK3CA genes. Targeted therapy with the FGFR inhibitor erdafitinib demonstrated a partial remission. Diffuse supratentorial spread of RGNT is an extremely rare presentation of an already uncommon pathology. In some cases, gross-total resection may not be feasible. Goals of surgery include acquiring tissue for diagnosis, maximizing safe resection, and treating any associated hydrocephalus. FGFR inhibitors may be of benefit in cases of disease progression.

OR32-04 The Usefulness Of The Contrast-enhanced Ultrasound (CEUS) In Evaluating The Risk Of Malignancy In Thyroid Nodules

Abstract Disclosure: A. Zylka: None. K. Dobruch-Sobczak: None. M. Jedrzejczyk: None. H. Piotrzkowska-Wroblewska: None. P. Goralski: None. J. Galczynski: None. E. Bakula-Zalewska: None. M. Dedecjus: None. Objectives Ultrasonography (US) is a primary method used in the evaluation of the thyroid nodules, but there is no single feature predicting malignancy preoperatively with high accuracy. Contrast-enhanced ultrasound (CEUS) provides information about the vascular perfusion and hemodynamics in the thyroid nodules. Therefore, the aim of this paper was to evaluate the usefulness of CEUS in the differential diagnosis of thyroid nodules. Methods Between the years 2021 and 2022, 182 adult patients (149 women and 33 men, aged 18-85) underwent CEUS of a thyroid nodule classified after fine-needle aspiration biopsy with II-VI Bethesda category. During CEUS examination 1.5 ml of SonoVue contrast has been injected and followed by analysing of qualitative CEUS enhancement patterns. All patients subsequently underwent thyroid operation and histopathologic results were used to confirm or exclude the risk of malignancy. Analysis of the visual CEUS enhancement patterns was performed by two experienced specialists in thyroid ultrasonography. Fifteen CEUS qualitative parameters of nodules were estimated and compared with normal thyroid parenchyma including: ring enhancement; low-, iso- and high enhancement; homo- or heterogenous enhancement; slow, fast or equal wash-in and wash-out and centripetal, centrifugal or diffuse enhancement. The statistical analysis of the obtained results was performed using the logistic regression. First sensitivity, specificity and AUC were calculated only for CEUS qualitative features. Then the model was extended using the results based on US B-mode imaging which involved three suspicious features: irregular margins, microcalcifications and marked hypoechogenicity. Results Histopathologic results included 61 benign thyroid nodules (in 51 women and 10 men) and 121 thyroid carcinomas (in 99 women and 22 men). The analysis has pointed five CEUS parameters statistically significant in differential diagnosis between benign and malignant thyroid nodules: low, homogenous and centrifugal enhancement, ring enhancement and slow-wash-out of the contrast. The model, using the above parameters evaluated the risk of malignancy of thyroid nodules with sensitivity of 85.12% and specificity of 45.90% with 0.75 AUC. Including the B-mode features, the sensitivity, specificity and AUC were 85.95%, 62.30% and 0.86, respectively. Conclusions Preliminary results indicate that CEUS is an useful tool in the evaluation of the risk of malignancy in thyroid nodules. The combination of the qualitative enhancement parameters and US B-mode sonographic features increases the usefulness of the method in differential diagnosis between benign and malignant nodules. However, further multicenter studies should be performed in order to standardize qualitative and quantitative CEUS features. Presentation: Sunday, June 18, 2023

FRI326 Hypophysitis: A Formidable Diagnostic Challenge

Abstract Disclosure: S. Pandey: None. C. Houston: None. Background: Hypophysitis, defined as inflammation of the pituitary gland, may pose a formidable diagnostic challenge due to its protean clinical manifestations and growing spectrum of potential causes. We present a case of a young man with presumed hypophysitis in whom the etiology remains unknown. Case Summary: A previously healthy 20-year-old male with bilateral gynecomastia was referred to the endocrinology clinic. He reported a 1-year history of worsening fatigue, weight gain, intermittent headaches, bilateral breast enlargement, lack of morning erections, polydipsia, and polyuria. His childhood growth and pubertal development were reportedly normal. He denied prior head or testicular trauma, major systemic illnesses, and chronic opiate or glucocorticoid use. His physical exam was remarkable only for scant facial hair and bilateral nontender gynecomastia. His visual fields were normal, and sense of smell was intact. Laboratory evaluation at 8am revealed low total and free testosterone of 32 ng/dL (240-950) and 0.98 ng/dL (5.25-20.7), respectively, with LH of 1.4 mIU/mL (1.0-12.0) and FSH of 1.9 mIU/mL (1.0-12.0). Free T4, prolactin, IGF-1, and serum sodium were all within normal ranges. Serum cortisol was modestly elevated at 22.3 ug/dL (3.7-19.4) with normal ACTH of 49 pg/mL (7.2-63.0). Pituitary MRI showed diffuse thickening and enhancement of the pituitary stalk, compatible with infundibular hypophysitis, without evidence of mass effect upon the native gland or surrounding structures. Additional testing showed normal levels of serum calcium, iron, ferritin, ESR, and antinuclear antibodies. After overnight water deprivation, his serum sodium was elevated at 156 mmol/L (134-144) with low urine osmolality of 121 mOsmol/kg (300-900). He was started on desmopressin and testosterone, and close clinical monitoring was enacted. Conclusion: The diagnosis of hypophysitis poses multiple challenges. Its clinical manifestations can vary widely, including symptoms related to mass effect and/or symptoms of pituitary dysfunction. Diagnosis is often presumptive based on history and exam, biochemical evaluation, and neuroimaging. The spectrum of potential causes is broad and growing, including infiltrative, infectious, neoplastic, immunoglobulin G4-related, immunotherapy-induced, other autoimmune, and paraneoplastic causes. It is often a humbling experience for clinicians to narrow this exhaustive differential. Pituitary biopsy is the gold standard for diagnosis but poses significant risks, so is reserved for cases when the diagnosis remains uncertain or malignancy is suspected. Close clinical monitoring and re-evaluation is an acceptable alternative in select cases. Presentation: Friday, June 16, 2023

SAT624 Neurosarcoidosis Presenting With Panhypopituitarism

Abstract Disclosure: E.M. Niedzialkowska: None. T. Blazin: None. K. Strubchevska: None. M. Kozyk: None. N. Saini: None. Introduction: Neurosarcoidosis is estimated to occur in approximately 5-15% patients with sarcoidosis. Pituitary involvement may be present in up to 5% of those cases and can manifest as hypothalamus, adenohypophysis dysfunction or arginine vasopressin deficiency (AVP-D) in isolated fashion or variedly combined. Clinical case: 32 year old male presented with chief complaint of worsening bilateral lower extremity weakness, urinary incontinence, polyuria and polydipsia. 9 months prior to admission the patient was diagnosed with neurosarcoidosis. At that time brain MRI showed diffuse leptomeningeal enhancement, chest CT showed hilar lymphadenopathy, lumbar puncture with CSF analysis showed protein 227 mg/dl (N<38), ACE 6 U/l (N <2.5), WBC 10 (N<5) with 88% lymphocytes. Hilar lymph node biopsy was consistent with non-caseating granuloma. The patient was diagnosed with neurosarcoidosis and started on prednisone and methotrexate. The patient was referred to our institution for further evaluation. On examination gait ataxia and gynecomastia were noted. Laboratory results showed urine specific gravity of 1.001, LH 0.4 mIU/ml (N 0.6-1.2), FSH 1.1 mIU/ml (N 1-12), ACTH <5 pg/ml (N 6-46), cortisol 2.1 ug/dl (N 2.9-19.4), prolactin 10.5 ng/ml (N 2-18), total testosterone 4 ng/dl (N 240-1080), free testosterone 0.1 ng/dl (N 4.8-19), TSH 0.58 uIU/ml (N 0.4-4.5), free ft3 1.5 pg/ml (N 1.7-3.7), free ft4 0.6 ng/dl (N 0.7-1.5), IGF-1 52 ng/ml (N 71-234), Copeptin proAVP of <2.8 pmol/l( N>13.2), urine osmolality of 72 mOsmol/kg, blood osmolality of 297 mOsmol/kg (N <295), vit D 25-OH 9 ng/ml (N 30-100), vit D 1,25-OH 57.3 pg/ml (N 19.9-79.3). MRI of the spine showed extensive nodular enhancement of the leptomeninges of the cervical, thoracic spine and lumbar cauda equina nerve roots. Brain MRI was positive for numerous small nodular enhancement involving leptomeninges and pituitary stalk. The patient was started on desmopressin with significant improvement of symptoms and increase in urine osmolality to 709 mOsmol/kg. Due to risk of hypercalcemia and normal vit D 1,25-OH vitamin D supplementation was not initiated. For neurosarcoidosis the patient was started on pulse dose methylprednisolone and infliximab infusion. Upon discharge he was transitioned to oral hydrocortisone and started on levothyroxine and testosterone replacement therapy. Conclusion: We present a case of pituitary neurosarcoidosis presenting with AVP-D, secondary hypothyroidism, secondary adrenal insufficiency, hypogonadism and growth hormone deficiency. Panhypopituitarism with complete anterior and posterior pituitary dysfunction is extremely rare and might be found in up to 13% cases of pituitary sarcoidosis. The diagnosis should be considered in patients with sarcoidosis and endocrine dysfunctions. Presentation: Saturday, June 17, 2023

Rectification behavior of a conical nanopore subject to extra simultaneously applied concentration and thermal gradients

The transport of ions in biological cells can be efficiently regulated by a uniformly distributed salt concentration and temperature in their ion channels. Attempting to understand the interactions between these two factors, we consider the ionic transport of a conical nanopore functionalized with bipolar polyelectrolyte (PE) layers subject to applied electric field, concentration gradient (∇C), and thermal gradient (∇T). The electrokinetic behavior of the system considered is primarily governed by ∇C which contributes to diffusion flow. In contrast, the contribution of ∇T is only auxiliary. Through varying the directions of ∇C and ∇T (four possible combinations), we show that the accumulation and depletion of ions in the nanopore are mainly influenced by the shielding effect of the charged region of PE layers. If a small negative voltage bias is applied, an anion-selective nanopore switches to a cation-selective one, and this phenomenon is pronounced when a higher concentration is placed on the nanopore tip side. However, that phenomenon is temperature independent. When ∇C is applied, the ionic current rectification factor Rf shows a maximum value as a higher concentration is placed on the nanopore tip side, while it monotonically decreases as a higher concentration is placed on the other side. As for applying ∇T, the rectification capability of the nanopore is only slightly affected. The ion selectivity S under opposite polarities of voltage bias shows unique phenomena: If V=+1V, S mainly depends on temperature, which is almost uniform in the nanopore. In contrast, S is dominated by concentration when V=−1V, which arises from the enhancement or offset of diffusion and migration fluxes.

Effect of Simultaneous Changes in Asphalt Binder Bee Structure Components on Mechanical Properties during the Aging and Rejuvenation Process

The bee structure of an asphalt binder surface changes during the aging and rejuvenation process, and the effect of this microstructural change on the mechanical properties of the asphalt binder is not clear. Therefore, in this paper, a two-dimensional finite element model of an asphalt binder microstructure was constructed based on processed AFM images, and the contents of bee phases and bee casings were varied at the same time to analyze the stress and strain distribution law of the asphalt binder microstructure. The results of the study show that in the bee structure, the stress in the bee phase is obviously greater than that in the bee casing, and the stress in the interstitial phase is the lowest. With the simultaneous enhancement in the proportion of the bee phase and the bee casing, the stresses in the asphalt samples increased in all phase structures. Under the combined effect of the decrease in the content of the bee phase and the increase in the content of the bee casing, there is a certain degree of increase in the internal stresses and strains in the asphalt binder, the effect of the bee casing on the internal stresses in the asphalt binder is more pronounced, and the bee phase and the bee casing play better roles in resisting the external deformation due to the increase in the volume fraction. For a recycled asphalt binder, whether there is an increase in the dosage of the old asphalt binder or an enhancement in the interfacial diffusion and a fusion of new and old asphalt binders, the level of tensile strain within the recycled asphalt binder will increase to a certain extent, which, in turn, will put forward a higher requirement for its anti-cracking ability.

Importance of satisfying thermodynamic consistency in optoelectronic device simulations for high carrier densities

We show the importance of using a thermodynamically consistent flux discretization when describing drift–diffusion processes within light emitting diode simulations. Using the classical Scharfetter–Gummel scheme with Fermi–Dirac statistics is an example of such an inconsistent scheme. In this case, for an (In,Ga)N multi quantum well device, the Fermi levels show an unphysical hump within the quantum well regions. This result originates from neglecting diffusion enhancement associated with Fermi–Dirac statistics in the numerical flux approximation. For a thermodynamically consistent scheme, such as the SEDAN scheme, the humps in the Fermi levels disappear. We show that thermodynamic inconsistency has far reaching implications on the current–voltage curves and recombination rates.

P16.01.A THE CASE OF AGGRESSIVE DIFFUSE LEPTOMENINGEAL GLIONEURONAL TUMOR IN ADULT TREATED WITH CRANIOSPINAL IRRADIATION AND TEMOZOLOMIDE

Abstract BACKGROUND Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare tumor, which was introduced as a separate entity in the 2016 World Health Organization classification of central nervous system tumors. It is most common in pediatric age, but very rare in adults. Literature demonstrates limited reports regarding treatment strategy in adult. We present a case of young female affected by DLGNT with aggressive behavior. MATERIAL AND METHODS A 28-year-old woman presented with severe headache and vomiting. Brain MRI showed diffuse leptomeningeal enhancement with hydrocephalus. At first, she was under suspicion of tuberculosis meningitis with mild increased protein level in CSF study. Her symptom rapidly improved after ventriculoperitoneal shunt and she started anti-tuberculosis medication. Despite 8-month of medication, her neurological status gradually deteriorated with paraparesis and follow-up MR images showed progression of disease. She underwent open biopsy of superficial brain lesions. RESULTS Intraoperatively, multiple nodular masses were attached inner side of dura mater and diffuse adhesion on subarachnoid space of brain surface. Histological examination revealed small round cells with oligodendroglial-like aspects. Immunohistochemistry showed positivity for Olig2, synaptophysin and S100. Chromosome 1p deletion was confirmed by FISH. Next-generation sequencing profile disclosed mutation of H3K28M, FGFR1 and ATRX. Diagnosis was consistent with DLGNT. She received craniospinal irradiation of 36 Gy in 20 fractions, then started chemotherapy with temozolomide (TMZ) at a dose 200mg/m2/day for 5 days in 4 weeks. After 4 cycles of TMZ, MR images demonstrated stable disease. CONCLUSION DLGNT is a very rare tumor in adult. Diagnosis needed high level of suspicion and histological confirmation. We present a very rare adult DLGNT patient with aggressive clinical features who showed stable state treated with craniospinal irradiation and TMZ chemotherapy.

T2-weighted imaging and dynamic contrast‑enhanced imaging in predicting the prognosis in patients with acute-on-chronic liver failure.

Acute-on-chronic liver failure (ACLF) is a syndrome with high 28- and 90-day mortality rates. Magnetic resonance imaging (MRI) has been widely used to diagnose and evaluate liver disease. Our purpose is to determine the value of the imaging features derived from Gd-DTPA-enhanced MRI for predicting the poor outcome of patients with ACLF and develop a clinically practical radiological score. This retrospective study comprised 175 ACLF patients who underwent Gd-DTPA-enhanced abdominal MRI from January 2017 to December 2021. The primary end-point was 90-day mortality. Imaging parameters, such as diffuse hyperintense of the liver on T2WI, patchy enhancement of the liver at the arterial phase, uneven enhancement of the liver at the portal vein phase, gallbladder wall edema, periportal edema, ascites, esophageal and gastric varix, umbilical vein patefac, portal vein thrombosis, and splenomegaly were screened. Cox proportional hazard regression models were used to evaluate prognostic factors and develop a prediction model. The accuracy of the model was evaluated by receiver operating characteristic (ROC) curves. During the follow-up period, 31 of the 175 ACLF patients died within 90 days. In the multivariate analysis, three imaging parameters were independently associated with survival: diffuse hyperintense on T2WI (p = 0.007; HR = 3.53 [1.40-8.89]), patchy enhancement at the arterial phase (p = 0.037; HR = 2.45 [1.06-5.69]), moderate ascites (vs. mild) (p = 0.006; HR = 4.12 [1.49-11.36]), and severe ascites (vs. mild) (p = 0.005; HR = 4.29 [1.57-11.71]). A practical radiological score was proposed, based on the presence of diffuse hyperintense (7 points), patchy enhancement (5 points), and ascites (6, 8, and 8 points for mild, moderate, and severe, respectively). Further analysis showed that a cut-off at 14 points was optimum to distinguish high-risk (score > 14) from the low-risk group (score ≤ 14) for 90-day survival and demonstrated a mean area under the ROC curve of 0.774 in ACLF patients. Gd-DTPA-enhanced MR imaging features can predict poor outcomes in patients with ACLF, based on which we proposed a clinically practical radiological score allowing stratification of the 90-day survival.