Do arachnoid cysts grow?

Summary The volumes of intracranial arachnoit cysts were measured in 136 CT scans of 86 patients. Absolute and relative cyst size was calculated. Left hemisphere and middle cranial fossa location prevailed. A slight negative correlation of relative cyst size with age (r=–0.21, NS) disappeared when analysis was restricted to the adult age group (20 years). After the sample was divided into two groups according to relative cyst size (cysts less than mean volume vs cysts greater than mean volume), small AC showed no correlation with age, while large AC correlated positively with age (r=0.79,P<0.05). A subgroup of large AC appears to expand with time, while the majority of small AC remain unchanged.     

Possibilities of application of the fixateur externe at the femur - indications, results (author's transl)

Besides the methods of screwing of plates and medullary nailing, the fixateur externe (F.E.) is another method which can be considered for treating bone fractures at the femur, F.E. being an exceptional indication. In fresh fractures of the femur, open fractures of the second and third grade as well as debris and multiple-plane fractures are typical indications for F.E. Over and above, F.E. is almost always indicated as an emergency measure in case of initial inoperability (polytrauma, shock, loss of blood, craniocerebral trauma) or continuing general inoperability. F.E. has been found useful to an even greater extent especially in old fractures, refractures, pseudarthroses and infected pseudarthroses. Combined treatment of the infected pseudarthroses with F.E. and Septopal balls has proved particularly effective. The special advantages of F.E. application at the femur are blood-saving surgery requiring relatively little time and technical equipment, avoidance of surgically conditioned infection risk in the fractured region, avoidance of additional denudation of free fracture fragments, long-term applicability, good external stabilization with selective possibility between compression, distraction and neutral positioning of the fractured area, postoperative treatment without dressing, and free access to the fractured area without interfering with the F.E.; furthermore, exchangeability of the F.E., possibility of correcting the position and axis without surgical intervention, non-fixation of the adjacent joints and maintenance of physiotherapeutic treatment possibilities. F.E. is "panacea" and should not be applied without exact knowledge of the static and mechanical and biomechanical conditions and effects. Before resorting to F.E. this must be carefully weighed against the use of internal osteosynthesis methods. It is not a rival method to plate screwing and medullary nailing but rather an auxiliary system whenever these methods are inapplicable or would entail disadvantages.     

Vergleich der Bromcyanbruchstücke von Glaskörperkollagen und Typ II Kollagen

Zusammenfassung Aus Rinderglaskörper wurde pepsin-lösliches Kollagen isoliert, das bei der Untersuchung mit der Disk-Elektrophorese eine -Komponente zeigte, die im 1-Bereich wanderte. Auffallend sind mehrere Farblinien zwischen der - und der -Komponente. Bei der Disk-Elektrophorese der Bromcyan-Peptide von pepsin-löslichem Glaskörperkollagen kann festgestellt werden, daß das Peptidmuster nicht mit dem identisch ist, das aus pepsin-löslichem Typ II Kollagen erhalten werden kann.

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Comparison of the cyanogen bromide peptides of vitreous body collagen and type II collagen

Summary Pepsin-soluble collagen was isolated from bovine vitreous humor. This collagen showed only one -chain in disc electrophoresis, migrating in the 1-chain position and between the - and -components some colored bands were visible. The disc electrophoretic patterns of the cyanogen bromide peptides of pepsinsoluble vitreous body collagen and pepsin-soluble type II collagen revealed no identity.

     

Selective neuronal survival and upregulation of PCNA in the rat inner retina following transient ischemia

In this study we investigated the extent and time course of neuronal cell death and the regulation of the proliferating cell nuclear antigen (PCNA) in the different retinal cell layers following ischemia-reperfusion injury. Retinal ischemia was induced by controlled elevation of the intraocular pressure for a duration of 60 min. Changes in thickness and cell numbers in the retinal cell layers were analyzed at various time points (1 h to 4 weeks) after reperfusion. In parallel, apoptotic cell death was determined by the TUNEL method and the expression of PCNA analyzed by immunocytochemistry. In addition, we tested whether PCNA is expressed in neurons by double immunocytochemistry. The reduction in thickness was found to be less pronounced in the inner nuclear layer (INL). Correspondingly, cell numbers decreased by only 33% in the inner retina, but by more than 80% in the outer nuclear layer (ONL). Alterations in glial cell numbers did not contribute significantly to postischemic changes in the INL and ONL as assessed by using immunocytochemical markers for microglial and Müller cells. The time course of cell death determined by the TUNEL technique also differed markedly in the retinal layers being rapid and transient in the inner retina but delayed and prolonged in the ONL. PCNA immunoreactivity was undetectable in the normal retina, but was specifically induced in neurons of the inner retina within 1 h after reperfusion and was sustained for at least 4 weeks. We conclude that in contrast to photoreceptors in the ONL, a significant proportion of inner retinal neurons is resistant to ischemic insult induced by transiently increased intraocular pressure and that PCNA may possibly play a role in the selective postischemic survival of these cells.     

Disease-specific alterations in frontal cortex brain proteins in schizophrenia, bipolar disorder, and major depressive disorder. The Stanley Neuropathology Consortium

Severe psychiatric disorders such as schizophrenia, bipolar disorder and major depressive disorder are brain diseases of unknown origin. No biological marker has been documented at the pathological, cellular, or molecular level, suggesting that a number of complex but subtle changes underlie these illnesses. We have used proteomic technology to survey postmortem tissue to identify changes linked to the various diseases. Proteomics uses two-dimensional gel electrophoresis and mass spectrometric sequencing of proteins to allow the comparison of subsets of expressed proteins among a large number of samples. This form of analysis was combined with a multivariate statistical model to study changes in protein levels in 89 frontal cortices obtained postmortem from individuals with schizophrenia, bipolar disorder, major depressive disorder, and non-psychiatric controls. We identified eight protein species that display disease-specific alterations in level in the frontal cortex. Six show decreases compared with the non-psychiatric controls for one or more diseases. Four of these are forms of glial fibrillary acidic protein (GFAP), one is dihydropyrimidinase-related protein 2, and the sixth is ubiquinone cytochrome c reductase core protein 1. Two spots, carbonic anhydrase 1 and fructose biphosphate aldolase C, show increase in one or more diseases compared to controls. Proteomic analysis may identify novel pathogenic mechanisms of human neuropsychiatric diseases.     

Removal of immunoglobulins by a protein A versus an antihuman immunoglobulin G-based system: evaluation of 602 sessions of extracorporeal immunoadsorption

Elimination of IgG can be achieved by extracorporeal immunoadsorption (IA) based on specific binding to either staphylococcal protein A (Excorim) or sheep polyclonal antibodies directed against human IgG (Therasorb). In 602 analyzed sessions of IA, elimination of IgG was 60% through 80% depending on the treated plasma volume, with no significant difference between the mentioned systems. However, the decrease of IgM and IgA was approximately 50% in the anti-IgG compared to 20-40% in the protein A system. Plasma albumin concentration decreased by 20% in the anti-IgG system compared to 15% in the protein A system, and hemoglobin values increased by 2% in the anti-IgG system and decreased by 6% in the protein A system. In conclusion, a clinical relevance for these findings cannot be ruled out, and the individual choice might depend on the clinical situation and laboratory findings.     

Particle release in extracorporeal low-density lipoprotein lowering therapies

Release of microparticles into the blood during extracorporeal circulation must be kept low because of possibly serious acute and chronic adverse effects. Concentration and size distribution of microparticles were measured during simulated treatments (n = 7) on original equipment for 2 standard low-density lipoprotein (LDL) elimination procedures (DALI 750, Fresenius AG, St. Wendel, Germany and Liposorber, Kaneka Corporation, Osaka, Japan) and compared to hemofiltration solutions. For both systems as well as in hemofiltration solutions, the mean particle concentrations in 500 ml portions gathered from the efferent blood line stayed below 10% of pharmacopoeia standards for infusion solutions (United States Pharmacopoeia, European Pharmacopoeia) in all measured size classes. Although particle concentrations were comparable in all systems, the mean total number of particles > or =2 microm released per session was lowest in the DALI (167,000) compared to the Liposorber (465,000) and hemofiltration solutions (2,240,000). This was mainly due to different total processed blood volumes necessary to achieve the required LDL reduction.     

Diagnostic imaging in femur head necrosis

Diagnosis of avascular necrosis (AVN) of the hip has been improved by the technical progress of imaging modalities during the last decade. For a long period, only plain radiographs had been available. Scintigraphy and computed tomography contributed to differential diagnosis and early detection of bone necrosis. In the meantime, MR imaging has gained special value in the evaluation of AVN. It is now the method of choice for early detection as well as for assessment in later stage disorders. Using the ARCO system, all imaging modalities and their diagnostic viability are described. Findings regarding the different stages of AVN are correlated to tissue-specific changes.     

Differential regulation of ciliary neurotrophic factor and its receptor in the rat hippocampus following transient global ischemia

To investigate a potential role of ciliary neurotrophic factor (CNTF) in transient global ischemia, we have studied the postischemic regulatory changes in the expression of CNTF and its receptor, the ligand-binding alpha-subunit (CNTFRalpha). Immunoblot analysis demonstrated CNTF levels were slightly upregulated already during the first day after ischemia and then increased markedly by more than 10-fold until 2 weeks postischemia. Immunoreactivity for CNTF became detectable 1 day after ischemia and was localized in reactive astrocytes. The intensity of the immunolabeling was maximal in CA1 during the phase of neuronal cell death (days 3-7 postischemia) and in the deafferented inner molecular layer of the dentate gyrus. Upregulation of CNTF expression was less pronounced in CA3 and absent in the stratum lacunosum moleculare and the outer molecular layer of the dentate gyrus and thus did not simply correlate with astroliosis as represented by upregulation of glial fibrillary acidic protein (GFAP). As shown by in situ hybridization, expression of CNTFRalpha mRNA was restricted to neurons of the pyramidal cell and granule cell layers in control animals. Following ischemia, reactive astrocytes, identified by double labeling with antibodies to GFAP, transiently expressed CNTFRalpha mRNA with a maximum around postischemic day 3. This astrocytic response was most pronounced in CA1 and in the hilar part of CA3. These results show that CNTF and its receptor are differentially regulated in activated astrocytes of the postischemic hippocampus, indicating that they are involved in the regulation of astrocytic responses and the neuronal reorganizations occurring after an ischemic insult.