Evidence of impaired carbohydrate assimilation in euthyroid patients with Hashimoto's thyroiditis.

BACKGROUND/OBJECTIVES: Hashimoto's thyroiditis (HT) represents a wide-spread autoimmune disease. In euthyroid patients with HT, an impaired assimilation of common carbohydrates has been observed. Our objectives were to compare the frequency of (1) fructose (FM), lactose (LM) and sorbitol malassimilation (SM), (2) gastrointestinal symptoms (GS) following carbohydrate ingestion and (3) recurrent GS relevant to the participants' daily lives. SUBJECTS/METHODS: We conducted a prospective case-control study of 45 ambulatory patients with HT and 38 healthy volunteers, matched with regard to age, gender and area of origin. Hydrogen breath tests with fructose, lactose, sorbitol and glucose were performed, the lactose testing additionally comprising measurements of capillary blood glucose (cBG). GS during the tests and recurrent GS concerning the participants' daily lives were assessed. A food-frequency questionnaire was administered. RESULTS: FM was diagnosed in 48.9% of patients compared with 26.3% of the control group (P=0.035). In all, 42.2% of patients with HT and 21.1% of healthy controls showed LM (P=0.04). FM and/or LM was present in 73.3% of the patients and in 42.1% of healthy controls (P=0.004). GS after the ingestion of fructose (P=0.003) or lactose (P=0.025) and recurrent GS were significantly more prevalent in the case group. The consumption of free fructose, lactose or sorbitol did not differ. CONCLUSIONS: Carbohydrate malassimilation and gastrointestinal complaints are frequent in euthyroid patients with HT, leading to novel clinical and pathophysiological considerations and concepts.

Successful treatment of Erdheim-Chester disease with combination of interleukin-1-targeting drugs and high-dose glucocorticoids.

Erdheim-Chester disease (ECD) is a rare histocytic disorder. We report a case of a 45-year-old male ECD patient with severe clinical manifestation (urinary obstruction due to retroperitoneal mass with hydronephrosis, involvement of long bones) and central nervous system involvement (hemiparesis, aphasia and diabetes insipidus). Diagnosis was confirmed by typical clinical, radiological and histological findings. Under immunosuppressive therapy with prednisolone and interleukin-1A receptor antagonist (Anakinra, Kineret, Swedish Orphan Biovitrum AB, Stockholm, Sweden), a rapid improvement of the patients' symptoms and condition was observed. This is the first report of a successful combination therapy of Anakinra and glucocorticoids. Furthermore, current literature about ECD and treatment options are discussed.

Common and uncommon imaging findings in progressive multifocal leukoencephalopathy (PML) with differential diagnostic considerations.

OBJECTIVE: To provide a practical review of the spectrum of possible imaging findings in patients with progressive multifocal leukoencephalopathy (PML) and to address differentials. CONCLUSION: PML manifests with a broad spectrum of imaging features. Besides knowledge of preferential location, extent, temporal course, enhancement, results of functional imaging and clinical setting, recognition of imaging findings reflecting active demyelination may help the clinician in appropriately narrowing down the differential diagnosis.

T2 and DWI in pilocytic and pilomyxoid astrocytoma with pathologic correlation.

OBJECTIVE: To quantify and compare T2 signal and apparent diffusion coefficient (ADC) in pilocytic and pilomyxoid astrocytoma (PA and PMA) and correlate results with myxoid content. METHODS: Echo-planar diffusion weighted images (DWI) and standard magnetic resonance imaging (MRI) findings were reviewed retrospectively in patients with PA (n=34) and PMA (n=8). Regions of interest (ROIs) were drawn on ADC maps within tumor parts with lowest ADC values. Apparent diffusion coefficient values in tumor were normalized to those in cerebrospinal fluid (ADC/CSF). The ratio of T2 signal intensity in solid tumor parts to CSF (T2/CSF) was registered. Myxoid matrix was histologically quantified retrospectively in 8 PMAs and 17 PAs and correlated with imaging findings. RESULTS: Mean ADC/CSF for PA and PMA was 0.53±0.10 and 0.69±0.10 (p<0.01). Mean T2/CSF for PA and PMA was 0.78±0.19 and 0.93±0.09 (p<0.01). Mean proportion of myxoid tumor matrix in PA was 50% (range, 10-100%) and 93% (range, 90-100%) in PMA (p=0.004). Eight patients (32%; all PA) had less than 50% myxoid content and 17 (68%; 8 PA; 9 PMA) had more. There was positive correlation of ADC/CSF, T2/CSF and ADC (r2=0.61, 0.65 and 0.60 respectively) and significant difference between the groups with more and less than 50% myxoid content (p=0.01 for ADC/CSF and T2/CSF and p=0.02 for ADC). CONCLUSIONS: General imaging features of PA and PMA are non-specific, ADC values and T2 signal intensity are generally higher in the latter, reflecting the proportion of myxoid matrix in these tumors.

Novel cell nucleus directed fluorescent tetraazacyclododecane-tetra-acetic acid compounds.

Peptide conjugates derived from the SV 40 T antigen nuclear localisation sequence (NLS) have been successfully used to translocate both fluorescein isothiocyanate (FITC) and Gadolinium (Gd)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) into the cytoplasm and nucleus of glioma cells. However, uptake occurred only in up to 35% of cells. To improve cellular uptake, we designed three novel FITC-labelled Gd-DOTA conjugates. In the first conjugate, the commonly used Gd-DOTA-complex was coupled to the nuclear localization sequence (NLS) of the Simian Virus (SV) 40 T antigen alone as a control. In the second conjugate, the Gd-DOTA-coupled SV 40 T antigen NLS was elongated by the HIV-1 tat peptide (HIV-NLS). A third conjugate, in which the Gd-DOTA-complex was coupled to the SV 40 T antigen NLS elongated by a peptide containing seven arginines and six aminohexanoic acids (Ahx6R7) was also synthesized (AHX-NLS). By means of confocal laser scanning microscopy, fluorescence activated cell sorting, magnetic resonance imaging (MRI) and viability tests we were able to demonstrate that the first conjugate containing only the NLS of the SV 40 T antigen stained the nuclei of no more than 10-12% of U373 and LN18 glioma cells, resulting in low signal intensity in MRI. The stained cells remained viable. After incubation with conjugates HIV-NLS and AHX-NLS the nuclei of up to 73% of U373 and LN18 glioma cells were stained. This was associated with high signal intensity in MRI and cell death. As previously shown, the gadolinium ion reduces cellular uptake of DOTA conjugates. To confirm this, the conjugates were produced with or without gadolinium. The gadolinium-free DOTA conjugates showed a higher cellular uptake rate and an increased cytotoxic potential.

Cellular uptake of cationic gadolinium-DOTA peptide conjugates with and without N-terminal myristoylation.

Cellular and nuclear uptake of dual labelled conjugates could be of great value for chemotherapy and cancer diagnostics. Therefore we designed conjugates in which gadolinium (Gd)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a contrast agent for magnetic resonance imaging and fluorescein isothiocyanate (FITC), a fluorescence marker were coupled to membrane translocation sequences (MTS). The MTSs we employed were the third helix of the Antennapedia homeodomain, the HIV-1 Tat peptide and the N-myristoylated HIV-1 Tat peptide. We used confocal laser scanning microscopy, fluorescence activated cell sorting, magnetic resonance imaging (MRI) and viability tests to examine the cellular and nuclear uptake of these conjugates into U373 glioma cells, as well as their cytotoxic effects. We found that the Antennapedia conjugate was taken up by no more than 20% of the cells. The HIV-1 Tat conjugate showed even lower uptake into less than 3% of cells. Interestingly, N-myristoylation of the HIV-1 Tat conjugate drastically improved its cellular uptake. Up to 70% of cells showed cellular and nuclear uptake of the N-myristoylated HIV-1 Tat conjugate. Conjugate cytotoxicity appears to correlate with cellular uptake.

A novel polyarginine containing Smac peptide conjugate that mediates cell death in tumor and healthy cells.

The seven N-terminal amino acids AVPIAQK (SmacN7) of the mitochondrial protein Smac (second mitochondria-derived activator of caspase) promote caspase activation by binding specifically to inhibitor of apoptosis proteins (IAPs) and blocking their inhibitory activity. SmacN7 cannot pass through the cell membrane, but to be of therapeutic use it would be essential for it to enter the cell. To achieve transmembrane transport of SmacN7 we coupled it to a novel fluorescein isothiocyanate (FITC)-labelled transmembrane transport peptide RRRRK(FITC)RRRR via ss-alanine to produce the conjugate AVPIAQKssA RRRRK(FITC)RRRR. Because IAPs are much more strongly expressed in the cytoplasm of tumor cells, we expected this conjugate to produce staining of the cytoplasm, and for this to be stronger in tumor cells than in healthy cells. Surprisingly, we found strong nuclear uptake of the Smac conjugate and of the transport peptide alone without subsequent release in both tumor cells and healthy cells from the bladder, prostate, and brain. This was accompanied by cell death. In contrast to expectations, it appears that the apoptotic effects observed do not result from the SmacN7 cargo alone.

Novel dual labelled nucleus-directed conjugates containing correct and mutant nuclear localisation sequences.

Gadolinium (Gd)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) is commonly used as contrast agent in magnetic resonance imaging (MRI), but cannot enter the cytoplasm or cell nucleus. We designed a tetrapeptide carrying fluorescein isothiocyanate (FITC) and Gd-DOTA. This conjugate was coupled to the nuclear localisation sequence (NLS) of the Simian Virus (SV) 40 T antigen elongated by four arginines. In a second conjugate one lysine of the original SV 40 T antigen NLS was replaced by threonine. An FITC-labelled DOTA-tetrapeptide conjugate lacking the NLS peptide served as a negative control. We tried to achieve sequence specific entry of the Gd-DOTA-complex into the cytoplasm and nucleus of human U373 and LN18 glioma cells. Using confocal laser scanning microscopy (CLSM), fluorescence activated cell sorting (FACS), magnetic resonance imaging (MRI) and viability tests we found that both NLS conjugates stained the cell nuclei of U373 and LN18 glioma cells, represented also by a rise in signal intensity compared to the native control in MRI. The majority of stained cells remained viable. All conjugates were also produced without Gd. The Gd-free DOTA-conjugates showed an increase in cellular uptake rate. Conjugate cytotoxicity correlated closely to cellular uptake. Gd-containing DOTA-conjugates directed to the cytoplasm or the nucleus may be the basis for the development of novel diagnostic agents.

Image-guided craniotomy for frontal sinus preservation during meningioma surgery.

OBJECTIVE: Preservation of the frontal sinus (FS) during the frontolateral approach to the skull base reduces morbidity, enhances patient comfort, and speeds up the surgical procedure. Due to its irregular outline, mental reconstruction of the borders of FS from two-dimensional images is challenging during surgery. This study was designed to evaluate the impact of neuronavigation on identification and preservation of the FS during frontolateral craniotomies. METHODS: Forty-five patients with pathologies located in the anterior skull base and in the parasellar region were included. A standard computed tomography (CT) sequence was obtained from each patient and uploaded onto an image-guidance system for volumetric rendering of 3D images. The outline of the FS was visualized and the distance between its lateral border and the mid-pupillary line (MPL) was measured. The results were used for navigated craniotomies and compared to the intra-operative findings. RESULTS: The FS was located medial, on and lateral to the MPL in 32, 4 and 9 cases, respectively. The individual outline of the FS could be identified with a mean target registration error of 1.4mm (+/-0.7 mm). The craniotomy could be custom-tailored for each patient according to the individualized landmarks while visualizing the lesion and the surgical landmarks simultaneously. Unintended opening of the frontal sinus or orbit did not occur in any of these cases. CONCLUSION: Image-guided craniotomies based on 3D volumetric image rendering allow for fast and reliable demarcation of complex anatomical structures hidden from direct view in frontolateral approaches. The outline of the frontal sinus and the orbit can be appraised at a glance providing additional safety and precision during craniotomy.

The use of high-frequency electromagnetics in brain tumour surgery.

OBJECTIVE: The first commercially available high-frequency electromagnetic field (EMF) system promises additional functionality for neurosurgical procedures. In a prospective study, we evaluated the optimal use as well as the limitations of this system designed for vaporizing tissue and for coagulation in brain tumour surgery. METHODS: For the microsurgical treatment of 63 consecutive patients with various intracranial tumours, the EMF system was used in addition to the standard neurosurgical instrumentarium. The system was assessed with respect to its compatibility with the operating room environment. Furthermore, attention was given to the particular techniques required to use the system most effectively. The efficiency of the investigated tool was monitored throughout the study. RESULTS: The EMF system functioned properly in all procedures and did not cause any complications. Specific handling techniques and electrode tip configurations could be defined for optimal use of high-frequency electromagnetics for vaporization and coagulation in different intraoperative settings. Thereby, the efficiency of the device could be increased throughout the study while ineffective use decreased from 7 to 2 cases. Although this tool is designed ergonomically and offers high tactile control, it cannot be used submerged in cerebrospinal fluid or under continuous irrigation, which makes it necessary to use it in tandem with suction devices to obtain a clear view on the surgical field. CONCLUSION: Maneuvering with the EMF system was substantially different to both monopolar and bipolar systems, clearly necessitating a learning curve for the surgeon. This device was found to be a valuable complementary tool to standard electrosurgical instruments when applied effectively and with elaborated techniques.

Surgical planning for retrosigmoid craniotomies improved by 3D computed tomography venography.

OBJECTIVE: It is impossible to precisely anticipate the crooked course of the transverse and sigmoid sinuses and their individual relationship to superficial landmarks such as the asterion during retrosigmoid approaches. This study was designed to evaluate this anatomical relationship with the help of a surgical planning system and to analyze the impact of these in vivo findings on trepanation placement in retrosigmoid craniotomies. METHODS: In a consecutive series of 123 patients with pathologies located in the cerebellopontine angle, 72 patients underwent surgical planning for retrosigmoid craniotomies based on 3D volumetric renderings of computed tomography venography. By opacity modulation of surfaces in 3D images the position of the asterion was assessed in relationship to the transverse-sigmoid sinus transition (TST) and compared to its intraoperative localization. We evaluated the impact of this additional information on trepanation placement. RESULTS: The spatial relationship of the asterion and the underlying TST complex could be identified and recorded in 66 out of 72 cases. In the remaining 6 cases the sutures were ossified and not visible in the 3D CT reconstructions. The asterion was located on top of the TST in 51 cases, above the TST in 4 cases, and below the TST in 11 cases. The location of the trepanation was modified in 27 cases due to the preoperative imaging findings with major and minor modifications in 10 and 17 cases, respectively. CONCLUSION: Volume-rendered images provide reliable 3D visualization of complex and hidden anatomical structures in the posterior fossa and thereby increase the precision in retrosigmoid approaches.

Transient encephalopathy after intrathekal methotrexate chemotherapy: diffusion-weighted MRI.

Methotrexate (MTX) is an indispensable antimetabolite for the treatment of oncological and immunological disorders in all age groups. Chronic leukoencephalopathy is a well know side effect of MTX, especially in conjunction with intrathecal administration and whole brain radio therapy. However, acute neurotoxicity with confusion, disorientation, seizures and focal deficits has also been reported. Because acute neurological symptoms in patients under chemotherapy for neoplastic disorders may have many reasons, MR-imaging is usually necessary to identify the underlying pathology. Apart from conventional sequences, diffusion-weighted imaging (DW-MRI) is frequently performed. We report on clinical and imaging findings of reversibly restricted diffusion in a patient with transient encephalopathy after intrathecal administration of MTX for recurrent acute lymphatic leukaemia.