Localization of claudin-3 in tight junctions of the blood-brain barrier is selectively lost during experimental autoimmune encephalomyelitis and human glioblastoma multiforme

In the central nervous system (CNS) complex endothelial tight junctions (TJs) form a restrictive paracellular diffusion barrier, the blood-brain barrier (BBB). During inflammation, BBB properties are frequently lost, resulting in brain edema. To investigate whether BBB leakiness correlates with molecular changes at BBB TJs, we performed immunofluorescence stainings for TJ molecules in a mouse model of experimental autoimmune encephalomyelitis (EAE) and in human tissue with glioblastoma multiforme (GBM). In TJs of healthy CNS vessels in both mouse and man we detected occludin, ZO-1, claudin-5 and claudin-3. In EAE brain and spinal cord sections we observed the selective loss of claudin-3 immunostaining from TJs of venules surrounded by inflammatory cuffs, whereas the localization of the other TJ proteins remained unchanged. In addition, selective loss of claudin-3 immunostaining was also observed in altered cerebral microvessels of human GBM. Our data demonstrate the selective loss of claudin-3 from BBB TJs under pathological conditions such as EAE or GBM when the integrity of the BBB is compromised, and therefore suggest that claudin-3 is a central component determining the integrity of BBB TJs in vivo.     

Childhood cerebellar hemangioblastoma does not predict germline or somatic mutations in the von Hippel-Lindau tumor suppressor gene

Tumor suppressor gene "knockout" models would predict that children who present with hemangioblastoma are likely to harbor germline mutation of the von Hippel-Lindau gene. We screened 6 pediatric patients with cerebellar hemangioblastoma for germline or somatic mutations of the von Hippel-Lindau gene. Two had prior clinical manifestations of von Hippel-Lindau disease and, as expected, had germline von Hippel-Lindau gene mutations. Four children with solitary hemangioblastoma did not have a detectable germline deletion, rearrangement, or point mutation in their von Hippel-Lindau gene, and tumor specimens in 3 of these 4 showed no somatic von Hippel-Lindau allelic loss. Solitary cerebellar hemangioblastoma in children does not predict a germline or somatic mutation in the von Hippel-Lindau tumor suppressor gene. The tumorigenesis of hemangioblastoma in younger patients may differ from that in adults, and may involve a molecular process unrelated to the von Hippel-Lindau tumor suppressor pathway.     

Relevance of Image Fusion for Target Point Determination in Functional Neurosurgery

Summary. Summary.   Background: For the treatment of medically refractory movement disorders such as Parkinson's disease, essential tremor and primary dystonia, deep brain stimulation (DBS) has become one of the main treatment options. The targets for implantation of the stimulation electrodes are various nuclei within the basal ganglia or the thalamic and subthalamic area. Accurate target localisation is of major importance for outcome and patient safety. The goal of this study was to evaluate the role of image fusion in the determination of target co-ordinates.   Method: We conducted a retrospective study on 10 patients in whom 17 DBS electrodes had been implanted. Coordinates of the anterior and posterior commissures and of the DBS targets were compared on pre- and postoperative computerised tomography (CT) and fused CT/magnetic resonance scans. The targets as defined on the images were further compared with the targets derived intra-operatively with microelectrode recordings (MER) and macrostimulation.   Findings: The achievable mean target accuracy was of the order of the diameter of the DBS electrode and of the accuracy of the image fusion algorithm, i.e. about 1 mm. However, the maximal differences were between 1.8 mm and 3.2 mm.   Interpretation: Image fusion is a helpful tool for accurate determination of target point co-ordinates in DBS. In combination with intraoperative, electrophysiological recordings and stimulation which are still considered to be the most reliable localisation methods, image fusion may help to discern the anatomical and functional three-dimensionality of the target nuclei. Image fusion may reduce the number of trajectories needed for intraoperative electrophysiological determination of the optimal electrode localisation and thus lower the risk of complications.     

Mucinous cystadenoma of the ovary in a 15-year-old girl

Benign neoplasms of the ovary originating from epithelial tissue are common tumors in adult women. They are, however, rarely seen in children or adolescent girls. Here the authors present a case of an ovarian mucinous cystadenoma in a premenarchal girl. To our knowledge, there are only 5 other cases reported in the literature.     

Salivary concentrations and plasma protein binding of carbamazepine and carbamazepine 10,11-epoxide in epileptic patients.

1. The relationships between saliva, free and total plasma concentrations of carbamazepine (CBZ) and carbamazepine 10,11-epoxide (CBZ-EP) were studied in 24 chronically medicated epileptic patients. Four patients were taking CBZ alone, while 20 were taking one or more additional anticonvulsant drugs. 2. The free fraction of CBZ in plasma ranged from 0.19 to 0.33 (mean 0.24) while the saliva:plasma (S:P) concentration ratios ranged from 0.20 to 0.35 (mean 0.27). The free fraction of CBZ-EP in plasma ranged from 0.16 to 0.50 (mean 0.32), while the S:P ratios ranged from 0.14 to 0.70 (mean, 0.43). The plasma protein binding and S:P ratios of these compounds appeared to be independent of age, sampling time and concurrently administered anticonvulsant drugs. 3. Significant linear relationships between saliva and total plasma concentrations and between saliva and free plasma concentrations were observed for both compounds (P less than 0.001). However, salivary concentrations of CBZ and CBZ-EP were significantly more reliable as predictors of their respective free plasma concentrations than of their respective total plasma concentrations (P less than 0.01). 4. It is concluded that measurement of CBZ and CBZ-EP in the saliva of chronically medicated epileptic patients provides a more reliable estimate of the pharmacodynamically active, free concentrations of these compounds in plasma.     

Real Time-PCR HBV-DNA Analysis: Significance and First Experience in Armed Forces

Background

HBV DNA quantitation is used extensively world wide for the diagnosis and monitoring of treatment of Hepatitis B virus (HBV) infection. However, it has still to be popular in India. The aim of this study was to quantitate HBV – DNA by Real time – PCR method in Hepatitis B and in immuno-compromised patients, to compare the results with HBeAg detection and to monitor the response to therapy of chronic Hepatitis B patients to antivirals.

Methods

Ninety one serum samples of Hepatitis group of patients (all HBsAg positive), 41 samples from immuno-compromised patients (all HBsAg negative) and 49 patients of Chronic Hepatitis B group (all HBsAg positive) were the subjects of this first ever study in Armed Forces. Twenty serum samples from healthy volunteers and non-hepatitis B patients served as negative controls. The amplification detection was carried out in a Rotor-Gene 2000-sequence detector

Results

Amongst Hepatitis B group, 33% (30/91) of the samples were positive for HBV-DNA and 26% (24/91) of samples were positive for HBeAg. In the immuno-compromised group of patients 14.6% (6/11) of samples were positive for HIV-DNA and 9.7% (4/41) were positive for HBeAg. Of the Chronic Hepatitis B patients on treatment, all (100%) were positive by HBV-DNA, whereas 29/49 (59.2%) were positive by HBeAg before treatment. After treatment with antivirals, 06/49 (12.2%) were positive by both tests and 11/49 (22.5%) were positive only by HBV-DNA. 32/49 (65.3%) patients became negative serologically after therapy.

Conclusion

HBeAg status did not necessarily reflect HBV-DNA level in the serum, as 10/91 (11%) in the Hepatitis B group, 2/41 (4.9%) in the immuno compromised group and 20/49 (40.8%) patients in the Chronic Hepatitis B group were positive for HBV-DNA but negative for HBeAg. HBV-DNA was not found to be positive amongst any of the negative controls. Real time – PCR is a sensitive and reproducible assay for HBV-DNA quantitation and may be started in Armed Forces referral centers in the near future.Key Words: Real time – PCR, Chronic Hepatitis B, HBV – DNA, Antivirals     

Anatomy of the cerebral ventricular system for endoscopic neurosurgery: a magnetic resonance study

Summary ?Background. Endoscopy has developed into an integral part of minimally invasive neurosurgery. For further technological innovations, detailed knowledge about the pathological anatomy is essential. The gross anatomy of the cerebral ventricular system has been meticulously investigated with ventriculography and casts. Extensive volumetric measurements based on neuroradiological images have been performed, but only little is known about the surgically relevant linear distances in patients with hydrocephalus. Method. Thirty healthy volunteers and thirty patients suffering from hydrocephalus were scanned with high-resolution 3-D magnetic resonance imaging sequences. The image volumes were sliced identically with the help of Siemens Prominence^? software. Individual anatomical measurements of the ventricular system were carried out, mean values and standard deviations were calculated, and different endoscopic approaches were investigated. Findings. In healthy volunteers the measurements confirmed the results obtained from ventriculography and anatomic casts. In hydrocephalic patients the ventricular system was found to be enlarged asymmetrically. The optimal neuroendoscopic approach showed considerable, interindividual variation. Interpretation. This 3-D magnetic resonance imaging study revealed surgically and clinically relevant aspects of the pathologic anatomy of hydrocephalic patients, in comparison to healthy volunteers. Individualized planning of the endoscopic approach appears to be warranted. Finally, the data provided a sound basis for the further development of neuroendoscopes. Published online June 4, 2003