A case of arrhythmogenic right ventricular cardiomyopathy without arrhythmias

ABSTRACT: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by recurrent coma, ventricular tachycardias and the replacement of the myocardium with fatty and fibrous tissue. We described a 42-year-old female patient without clinical arrhythmias which was diagnosed as ARVC by magnetic resonance imaging (MRI), but the transvenous endomyocardial biopsy was not specific. The patient received heart transplantation due to her refractory heart failure and the pathology of explanted heart demonstrated typical replacement of fatty and fibrous tissue and piles of infiltrated lymphocytes in myocardial tissue. It is concluded that ARVC might not have any arrhythmias and inflammatory process may be involved in the mechanism of ARVC. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6573514507145351.     

Accurate state estimation from uncertain data and models: an application of data assimilation to mathematical models of human brain tumors

Background

Data assimilation refers to methods for updating the state vector (initial condition) of a complex spatiotemporal model (such as a numerical weather model) by combining new observations with one or more prior forecasts. We consider the potential feasibility of this approach for making short-term (60-day) forecasts of the growth and spread of a malignant brain cancer (glioblastoma multiforme) in individual patient cases, where the observations are synthetic magnetic resonance images of a hypothetical tumor.

Results

We apply a modern state estimation algorithm (the Local Ensemble Transform Kalman Filter), previously developed for numerical weather prediction, to two different mathematical models of glioblastoma, taking into account likely errors in model parameters and measurement uncertainties in magnetic resonance imaging. The filter can accurately shadow the growth of a representative synthetic tumor for 360 days (six 60-day forecast/update cycles) in the presence of a moderate degree of systematic model error and measurement noise.

Conclusions

The mathematical methodology described here may prove useful for other modeling efforts in biology and oncology. An accurate forecast system for glioblastoma may prove useful in clinical settings for treatment planning and patient counseling.

Reviewers

This article was reviewed by Anthony Almudevar, Tomas Radivoyevitch, and Kristin Swanson (nominated by Georg Luebeck).     

Noninvasive Cardiac Flow Assessment Using High Speed Magnetic Resonance Fluid Motion Tracking

Cardiovascular diseases can be diagnosed by assessing abnormal flow behavior in the heart. We introduce, for the first time, a magnetic resonance imaging-based diagnostic that produces sectional flow maps of cardiac chambers, and presents cardiac analysis based on the flow information. Using steady-state free precession magnetic resonance images of blood, we demonstrate intensity contrast between asynchronous and synchronous proton spins. Turbulent blood flow in cardiac chambers contains asynchronous blood proton spins whose concentration affects the signal intensities that are registered onto the magnetic resonance images. Application of intensity flow tracking based on their non-uniform signal concentrations provides a flow field map of the blood motion. We verify this theory in a patient with an atrial septal defect whose chamber blood flow vortices vary in speed of rotation before and after septal occlusion. Based on the measurement of cardiac flow vorticity in our implementation, we establish a relationship between atrial vorticity and septal defect. The developed system has the potential to be used as a prognostic and investigative tool for assessment of cardiac abnormalities, and can be exploited in parallel to examining myocardial defects using steady-state free precession magnetic resonance images of the heart.     

Effects of acute and chronic hyperglycemia on the neurochemical profiles in the rat brain with streptozotocin-induced diabetes detected using in vivo ¹H MR spectroscopy at 9.4 T

Chronic hyperglycemia could lead to cerebral metabolic alterations and CNS injury. However, findings of metabolic alterations in poorly managed diabetes in humans and animal models are rather inconsistent. We have characterized the cerebral metabolic consequences of untreated hyperglycemia from the onset to the chronic stage in a streptozotocin-induced rat model of diabetes. In vivo 1H magnetic resonance spectroscopy was used to measure over 20 neurochemicals longitudinally. Upon the onset of hyperglycemia (acute state), increases in brain glucose levels were accompanied by increases in osmolytes and ketone bodies, all of which remained consistently high through the chronic state of over 10 weeks of hyperglycemia. Only after over 4 weeks of hyperglycemia, the levels of other neurochemicals including N-acetylaspartate and glutathione were significantly reduced and these alterations persisted into the chronic stage. However, glucose transport was not altered in chronic hyperglycemia of over 10 weeks. When glucose levels were acutely restored to euglycemia, some neurochemical changes were irreversible, indicating the impact of prolonged uncontrolled hyperglycemia on the CNS. Furthermore, progressive changes in neurochemical levels from control to acute and chronic conditions demonstrated the utility of 1H magnetic resonance spectroscopy as a non-invasive tool in monitoring the disease progression in diabetes.     

Spontaneous renal artery dissection

Spontaneous renal artery dissection (SRAD) is a rare event, and thus may be a challenge for physicians to diagnose and treat. We report a case of SRAD in a healthy 56-year-old male who presented with flank pain, fever, and elevated white blood cell count. The patient was initially diagnosed with nephrolithiasis versus pyelonephritis and was admitted for observation. Multiple imaging modalities, including non-contrast computed tomography (CT), magnetic resonance imaging (MRI) with gadolinium, CT angiogram, and intraoperative angiogram, were used to make the final diagnosis of SRAD. The patient was treated with endovascular stent placement and is currently free of pain with normal laboratory values and blood pressure.     

Endocrine Dysfunction in A Patient with Phace Syndrome,Including Port-Wine Stain of the Right Periorbital Area

ObjectiveTo report a case of PHACE syndrome— Posterior fossa brain abnormalities, Hemangioma (usually facial), Arterial anomalies, Coarctation of the aorta along with cardiac defects, and Eye abnormalities—in a 16-yearold female patient with a port-wine stain of the right periorbital area present since birth in conjunction with hypoplasia of the contralateral internal carotid artery.MethodsThyroid-stimulating hormone, free thyroxine, and growth hormone (GH) levels were measured, and insulin-induced hypoglycemia and arginine infusion tests were done. Radiologic investigations included sagittal enhanced T1-weighted magnetic resonance imaging of the brain and the pituitary gland as well as computed tomography and magnetic resonance angiography of the head and neck.ResultsThe patient had a normal karyotype. Her height and weight were below the 5th percentile for her chronologic age, and she had amenorrhea. Laboratory investigations revealed both thyroid and GH deficiencies and confirmed the diagnosis of hypogonadotropic hypogonadism. The imaging studies showed a right intraorbital hemangioma as well as an enhancing mass in the right internal auditory canal at the cerebellopontine angle, consistent with a posterior fossa hemangioma. Initiation of both thyroid and GH replacement therapy improved her growth rate and yielded a good clinical outcome.ConclusionIn patients with facial or neck hemangiomas, PHACE syndrome should be suspected, and brain imaging and cardiac, ophthalmologic, and endocrinologic evaluations are recommended to screen for other potential PHACE abnormalities. (Endocr Pract. 2010;16:255-259)     

In vivo nuclear magnetic resonance spectroscopy studies of the relationship between the glutamate-glutamine neurotransmitter cycle and functional neuroenergetics.

In this article we review recent studies, primarily from our laboratory, using 13C NMR (nuclear magnetic resonance) to non-invasively measure the rate of the glutamate-glutamine neurotransmitter cycle in the cortex of rats and humans. In the glutamate-glutamine cycle, glutamate released from nerve terminals is taken up by surrounding glial cells and returned to the nerve terminals as glutamine. 13C NMR studies have shown that the rate of the glutamate-glutamine cycle is extremely high in both the rat and human cortex, and that it increases with brain activity in an approximately 1:1 molar ratio with oxidative glucose metabolism. The measured ratio, in combination with proposals based on isolated cell studies by P. J. Magistretti and co-workers, has led to the development of a model in which the majority of brain glucose oxidation is mechanistically coupled to the glutamate-glutamine cycle. This model provides the first testable mechanistic relationship between cortical glucose metabolism and a specific neuronal activity. We review here the experimental evidence for this model as well as implications for blood oxygenation level dependent magnetic resonance imaging and positron emission tomography functional imaging studies of brain function.     

First report of glucose transporter 1 deficiency syndrome in Korea with a novel splice site mutation

Glucose transporter type 1 deficiency syndrome (Glut-1DS) is caused by autosomal dominant haplodeficiency or autosomal recessive with homozygous mutation of the glucose transporter 1 (SLC2A1) gene and is characterized by severe seizures, developmental delay, ataxia and acquired microcephaly. We describe the first known Korean patient with glucose transporter 1 deficiency syndrome, who had a novel mutation in the splice site. The patient began having intractable seizures at 4days of age that initially presented as eye blinking and apnea, evolving into generalized tonic seizures. A lumbar puncture revealed low glucose concentration in the cerebrospinal fluid (CSF) in the setting of normoglycemia (blood glucose, 106mg/dl; CSF glucose 21mg/dl, and CSF to blood glucose ratio 0.20). The results of a 3-O-methylglucose uptake study in erythrocytes (RBC) revealed that glucose uptake reduced to 48% of his parents in the patient. The patient responded to a ketogenic diet that was initiated at 4months of age and currently is on the modified Atkins diet (MAD) without seizures. He does not require antiepileptic medication. We diagnosed the first Glut-1 patient in Korea with a novel splice site mutation on the basis of clinical features, deficient glucose uptake and a mutation in the SLC2A1 gene.     

Plurihormonal Pituitary Adenoma Immunoreactive for Thyroid-Stimulating Hormone,Growth Hormone,Follicle-Stimulating Hormone,and Prolactin

ObjectiveTo describe the case of a patient with an unusual plurihormonal pituitary adenoma with immunoreactivity for thyroid-stimulating hormone (TSH), growth hormone, follicle-stimulating hormone, prolactin, an α-subunit.MethodsWe report the clinical, laboratory, imaging, and pathology findings of a patient symptomatic from a plurihormonal pituitary adenoma and describe her outcome after surgical treatment.ResultsA 60-year-old woman presented to the emergency department with headaches, blurry vision, fatigue, palpitations, sweaty hands, and weight loss. Her medical history was notable for hyperthyroidism, treated intermit with methimazole. Magnetic resonance imaging disclosed a pituitary macroadenoma (2.3 by 2.2 by 2.0 cm), and preoperative blood studies revealed elevated levels of TSH at 6.11 mIU/L, free thyroxine at 3.6 ng/dL, and free triiodothyronine at 6.0 pg/mL. She underwent an uncomplicated transsphenoidal resection of the pituitary adenoma. Immunostaining of tumor tissue demonstrated positivity for not only TSH but also growth hormone, follicle-stimulating hormone, prolactin, and α-subunit. The Ki-67 index of the tumor was estimated at 2% to 5%, and DNA repair enzyme O6-methylguanine-DNA methyltransferase immunostaining was mostly negative. Electron microscopy showed the ultrastructural phenotype of a glycoprotein-producing adenoma. Postoperatively, her symptoms and hyperthyroidism resolved.ConclusionThyrotropin-secreting pituitary adenomas are rare. Furthermore, recent reports suggest that 31% to 36% of adenomas may show evidence of secretion of multiple pituitary hormones. This case emphasizes the importance of considering pituitary causes of thyrotoxicosis and summarizes the clinical and pathology findings in a patient with a plurihormonal pituitary adenoma. (Endocr Pract. 2012;18:e121-e126)     

Autoimmune Hyperthyroidism due to Secondary Adrenal Insufficiency: Resolution with Glucocorticoids

ObjectiveTo describe the course of autoimmune hyperthyroid disease in a patient with corticotropin (ACTH) deficiency treated with glucocorticoids.MethodsWe report the clinical presentation, laboratory data, imaging studies, and management of a patient with weight loss, fatigue, apathy, hallucinations, and arthritis.ResultsAutoimmune hyperthyroidism (positive thyroperoxidase and thyroglobulin antibodies and borderline positive thyrotropin receptor antibody) was diagnosed in a 71-year-old woman. New psychotic symptoms prompted brain magnetic resonance imaging, which revealed a partially empty sella. Undetectable morning cortisol, undetectable ACTH, and failure to stimulate cortisol with synthetic ACTH (cosyntropin 250 mcg) secured the diagnosis of long-standing secondary adrenal insufficiency. Hydrocortisone replacement improved the patient’s symptoms, resolved the thyroid disease, and decreased thyroid antibody titers. In retrospect, the patient recalled severe postpartum hemorrhage requiring blood transfusion at age 38 years. A Sheehan event probably occurred 33 years before the patient presented with corticotropin deficiency. Hyperthyroidism accelerated cortisol metabolism and provoked symptoms of adrenal insufficiency.ConclusionsThe hypocortisolemic state may precipitate hyperimmunity and autoimmune thyroid disease. Rapid resolution of hyperthyroidism and decreased thyroid antibody titers with glucocorticoid treatment support this hypothesis. (Endocr Pract. 2011;17:85-90)     

Proton correlation nuclear magnetic resonance study of anaerobic metabolism of Escherichia coli.

Proton correlation nuclear magnetic resonance has been used to investigate anaerobic metabolism of glucose in Escherichia coli cells. The time course of the concentrations of six metabolites (ethanol, lactate, acetate, pyruvate, succinate, and formate) has been followed at the very early state of fermentation, and used to discuss dynamical aspects of the mixed-acid fermentation of glucose by E. coli.     

Potentialities of magnetic resonance imaging in the study of renal morphofunctional state in girls with internal genital malformations and space-occupying lesions

The diagnosis of the anatomic and functional state of urinary organs in girls with internal genital malformations and space-occupying lesions involves magnetic resonance imaging by administering the optimized dose of a magnetic resonance contrast agent (MRCA). The technology makes it possible to evaluate the anatomic features of the urinary tract (magnetic resonance urography), to perform abdominal vascular magnetic resonance angiography, and to draw a conclusion on renal functional status in the use of dynamic magnetic resonance renography. Within a study using one injected MRCA dose, both the anatomic and functional state of the kidney status can be examined, by evaluating MRCA passage singly in the cortical and medullary substances and pelvises, which increases diagnostic accuracy by 46% and promotes the optimization of management tactics in this category of patients.     

Bilateral Ovary Adrenal Rest Tumor in a Congenital Adrenal Hyperplasia Following Adrenalectomy

Objective:In contrast to the high incidence of testicular adrenal rest tumors in adult male patients with congenital adrenal hyperplasia (CAH), ovarian adrenal rest tumors (OARTs) in female CAH patients are rare. In this case report, we describe a case of bilateral OART in a female patient with CAH due to 21-hydroxylase deficiency.Methods:We present a detailed case report with the clinical, imaging, and laboratory findings of the patient. The pertinent literature is also reviewed.Results:A 17-year-old patient was known to have CAH due to 21-hydroxylase deficiency. Since the second month of her gestational age, her mother was treated with cortisone-replacement therapy. The patient was treated with hydrocortisone and fludrocortisone since the neonatal period. Her pertinent history included a bilateral adrenalectomy at the age of 13 years in 2006, and for 3 years she led a normal puberty life with no complaint with hormonal replacement therapy. Nevertheless, in 2009, she developed a virilizing syndrome. Subsequently, she underwent surgery in December 2009 for right adnexectomy. However, the regression of the masculinizing mass was not complete and worsened several months after the surgery. A new pelvic magnetic resonance image showed the activation of a contralateral ovarian mass, necessitating a left adnexectomy in August 2010.Conclusion:This case demonstrates some interesting features of OART that pose challenges to its management. If an OART is detected early enough and glucocorticoid therapy is received, it is possible that the OART will decrease in size following suppression of adrenocorticotropic hormone levels. (Endocr Pract. 2014;20:e69-e74)     

Malaria parasite-infected erythrocytes inhibit glucose utilization in uninfected red cells

The erythrocytic stages of the malaria parasite depend on anaerobic glycolysis for energy. Using [2-13C]glucose and nuclear magnetic resonance, the glucose utilization rate and 2,3-diphosphoglycerate (2,3-DPG) level produced in normal RBCs and Plasmodium falciparum infected red blood cell populations (IRBCs, with <4% parasite infected red cells), were measured. The glucose flux in IRBCs was several-folds greater, was proportional to parasitemia, and maximal at trophozoite stage. The 2,3-DPG levels were disproportionately lower in IRBCs, indicating a downregulation of 2,3-DPG flux in non-parasitized RBCs. This may be due to lowered pH leading to selective differential inhibition of the regulatory glycolytic enzyme phosphofructokinase. This downregulation of the glucose utilization rate in the majority (>96%) of uninfected RBCs in an IRBC population may have physiological implications in malaria patients.     

Apoplexy of A Microprolactinoma During Pregnancy: Case Report and Review of Literature

ObjectiveTo report a rare case of apoplexy in a microprolactinoma during pregnancy.MethodsWe present the initial clinical manifesta tions, laboratory results, radiologic findings, and man agement in a patient who had pituitary apoplexy during early pregnancy. The pertinent literature and management options are also reviewed.ResultsA 37-year-old woman with a history of a microprolactinoma presented during the 16th week of her first pregnancy with a sudden onset of severe headache, nausea, vomiting, and blurred vision. Magnetic resonance imaging showed a sellar heterogeneous mass with supra sellar extension and contact with the optic chiasm, com patible with adenoma apoplexy. The patient’s visual fields were normal. Conservative management was followed by rapid clinical improvement and a notable regression of the sellar mass after 5 weeks of cabergoline therapy. Uneventful pregnancy resulted in the delivery of a healthy baby. Repeated magnetic resonance imaging was per formed 1 week after delivery and showed resolution of the microadenoma. At 3 months after delivery, the patient had recovered regular menses and had sustained normal prolac tin levels without treatment.ConclusionThis case illustrates a rare occurrence of apoplexy in a microprolactinoma during pregnancy, which was managed conservatively and led to a complete regression of the pituitary tumor. 3Endocr Pract. 2012;18:e147-e150)     

Brain Metabolism and Intracellular pH During Ischaemia and Hypoxia: An In Vivo 31P and 1H Nuclear Magnetic Resonance Study in the Lamb

Brain metabolism and intracellular pH were studied during and after episodes of ischaemia and hypoxia-ischaemia in lambs anaesthetised with sodium pentobarbitone. 31P and 1H magnetic resonance spectroscopy methods were used to monitor brain pHi and brain concentrations of Pi, phosphocreatine (PCr), beta--nucleoside triphosphate (beta NTP), and lactate. Simultaneous measurements were made of cerebral blood flow and cerebral oxygen and glucose consumption. Cerebral ischaemia sufficient to reduce oxygen delivery to 75% of control values was associated with a fall in brain pHi and increase in brain Pi. Progressively severe hypoxia-ischaemia was associated with a progressive fall in brain pHi, PCr, and beta NTP and increase in brain Pi. In two animals the increase in brain lactate during hypoxia-ischaemia measured by 1H nuclear magnetic resonance (NMR) could be quantitatively accounted for by the increased net uptake of glucose by the brain in relation to oxygen, but was insufficient to account for the concomitant acidosis according to previous estimates of brain buffering capacity. In four animals brain pHi, PCr, Pi, and beta NTP had returned to normal 1 h after the hypoxic-ischaemic episode. In one animal brain pHi had reverted to normal at a time when 1H NMR indicated persistent elevation of brain lactate.     

Quantitative assessment of acute kidney injury by noninvasive arterial spin labeling perfusion MRI: a pilot study

The kidneys are essential for maintaining homeostasis, are responsible for the reabsorption of water, glucose and amino acids, and filter the blood by removing waste. Acute kidney injury (AKI) is a syndrome characterized by the rapid loss of renal excretory function and the accumulation of end metabolic products of urea and creatinine. AKI is associated with the later development of chronic kidney disease and end-stage kidney disease, and may eventually be fatal. Early diagnosis of AKI and assessments of the effects of treatment, however, are challenging. The pathophysiological mechanism of AKI is thought to be the imbalance between oxygen supply and demand in the kidneys. We have assessed the ability of arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI), without the administration of contrast media, to quantify renal blood flow (RBF) non-invasively. We found that RBF was significantly lower in AKI patients than in healthy volunteers. These results suggest that ASL perfusion MRI, a noninvasive measurement of RBF, may be useful in the early diagnosis of AKI.     

Primary leiomyosarcoma of the inferior vena cava presenting as a renal mass

Leiomyosarcoma of the inferior vena cava (IVC) is an extremely rare entity. We present the case of a 62-year-old woman who was found to have a large right upper quadrant mass upon examination by her primary care physician in evaluation for diffuse abdominal pain accompanied by anorexia and weight loss. A computed tomographic scan and magnetic resonance imaging demonstrated a 13-cm retroperitoneal lesion that appeared to stem from the right kidney and yielded a tumor thrombus up to the level of the hepatic venous confluence. The patient underwent a right radical nephrectomy and IVC thrombectomy for treatment of a presumed renal cell carcinoma. Instead, pathology revealed the tumor to be a leiomyosarcoma of the IVC. We document this unusual presentation of an extremely rare tumor entity.     

Silicone breast implants and magnetic resonance imaging screening for rupture: do U.S. Food and Drug Administration recommendations reflect an evidence-based practice approach to patient care?

Regular magnetic resonance imaging has been recommended for the purpose of screening for silicone implant rupture. However, when its use as a screening test is critically examined, it appears that evidence to support its use is lacking. For example, there is no conclusive evidence at this time to show that using magnetic resonance imaging screening of asymptomatic women leads to a reduction in patient morbidity. Furthermore, based on existing data, it is unclear whether the potential benefits of screening magnetic resonance imaging tests outweigh the risks and potential costs for the patient. In the face of this uncertainty, shared medical decision making can be recommended. For different women, underlying beliefs and values will sway decision making in different directions. By engaging a woman in the process of shared medical decision making, however, the plastic surgeon and her or his patients can make a mutually agreeable choice that reflects the patient's individual values and health preferences.     

Precocious Puberty Due to Rathke Cleft Cyst in a Child

ObjectiveTo report a case of a child with precocious puberty attributable to Rathke cleft cyst (RCC).MethodsThe clinical features, laboratory results, and findings on ultrasonography of the pelvis and magnetic resonance imaging of the pituitary gland are presented.ResultsA 16-month-old child had breast enlargement, height increase, and an increase in growth velocity. On examination, she was found to have Tanner stage 3 breast development, and her vaginal mucosa was estrogenized. Her height was above the 97th percentile. Biochemically, she was diagnosed as having central precocious puberty, and magnetic resonance imaging of her pituitary gland disclosed RCC. Treatment with leuprolide resulted in normalization of her growth rate and regression of the breast development; the vaginal mucosa also became unestrogenized.ConclusionAlthough RCC is a relatively common finding, it is a rare cause of precocious puberty. Magnetic resonance imaging of the pituitary gland should be performed in all children younger than 6 years of age who have precocious puberty, in an effort to detect any organic lesions. (Endocr Pract. 2009;15:134-137)