Peroxiredoxins and antioxidant enzymes in pilocytic astrocytomas.

OBJECTIVE: Peroxiredoxins are antioxidant enzymes (AOEs), which are redox-regulated thiol proteins with potential effects on the growth, invasion and drug resistance of neoplastic cells. In this study, their biology and clinical significance were examined in pilocytic astrocytomas (PAs). MATERIAL AND METHODS: The expression of peroxiredoxins (Prx I-VI) was investigated in 105 PAs by the means of immunohistochemistry and compared with the expression of selected other antioxidant enzymes, cell proliferation, angiogenesis, apoptosis, p53, histopathology and patient survival. RESULTS: Peroxiredoxins were strongly expressed in general suggesting that oxidative damage and consequent defense takes place during the progression of pilocytic astrocytomas. In agreement with this hypothesis, several other AOEs correlated with the degenerative features and angiogenesis possibly associated with reactive oxygen species-derived cellular damage. Moreover, the expression of the AOEs was associated with each other indicating a concurrent activation of the enzymes. With the exception of manganese superoxide dismutase (MnSOD), a strong expression of AOEs was generally associated with higher cell proliferation. Prx VI seemed to have a positive association with a longer recurrence-free interval while other AOEs had no association with patient survival. Many AOEs, such as MnSOD, induce chemo- and radioresistance and are highly elevated in aggressive malignancies. PAs lack this confounding factor, and these tumors are treated only by surgery. CONCLUSIONS: Taken together, the results of this study on pilocytic astrocytomas suggest that the levels of Prxs and other AOEs and their related thiol proteins are generally strongly expressed in these tumors. At least Prx VI can contribute to tumor behavior which can make it a potential prognostic factor.

Preoperative clinical evaluation, outline of surgical technique and outcome in temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) is the most common type of refractory epilepsy. The mechanisms of epileptogenesis and seizure semiology of the mesial and neocortical temporal lobe epilepsy are discussed. The evaluation and selection of patients for TLE surgery requires team work: the different clinical aspects of neuropsychological evaluation, magnetic resonance and functional imaging (positron emission tomography, single photon emission computed tomography and magnetoenephalography) are reviewed. In our programme of epilepsy surgery at Kuopio University Hospital, Finland, we have performed 230 temporal resections from 1988 until 2002. Preoperative diagnostic EEG-videotelemetry often required intracranial monitoring and it has proved to be safe and efficient. The indications and technique for tailored temporal lobe resection with amygdalohippocampectomy used in our institution, as well as the complications, are described. Our analysis of outcome after temporal lobe surgery included 140 consecutive adult patients between 1988 and 1999; one year after the operation in unilateral TLE the Engel I-II outcome was observed in 68% of the patients. Outcome of surgery improved significantly after introduction of the standardised MR imaging protocol from 1993; 74% of patients with unilateral TLE achieved Engel I-II outcome.

Five-year outcome of normal pressure hydrocephalus with or without a shunt: predictive value of the clinical signs, neuropsychological evaluation and infusion test.

BACKGROUND: Between 1993-1995, 51 patients under 75 years of age with clinical symptoms and CT-based diagnosis of normal pressure hydrocephalus were investigated prospectively in order to clarify the value of neuropsychological tests, clinical symptoms and signs and infusion test in the differential diagnosis and prediction of outcome in normal pressure hydrocephalus. METHODS: Patients had a thorough neurological examination, and neuropsychological evaluation. A 24-hour intraventricular ICP-measurement, infusion test, neurophysiological investigations and MRI study were performed, and a cortical biopsy was obtained. The ICP measurement defined the need for a shunt. All 51 patients were re-examined three and twelve months later. The final follow-up was accomplished five years postoperatively. FINDINGS: 25 of the patients needed a shunt operation. One year after a shunt placement 72% of these patients had a good recovery concerning activities of daily living, 58% benefited in their urinary incontinence and 57% walked better. During the 5 years of follow-up 8 patients with shunt and 9 without shunt had died. Positive effect of shunting remained. Only one neuropsychological test, recognition of words test, distinguishes the patients with the need for a shunt. Simple mini mental examination test was not different in those who improved. In the postoperative follow-up patients with shunt showed no change in neuropsychological tests even if they were subjectively better. The infusion test was of no value in diagnosing NPH. The 16 patients with Alzheimer's disease did worse after one year than those without pathological changes, but the mortality was not increased. INTERPRETATION: Specific neuropsychological tests are of little value in diagnosing NPH. Mini-Mental status examination was neither of value in diagnosing NPH nor in prediction of the outcome. In this study the infusion test did not improve diagnostic accuracy of NPH, but shunt placement relieves urinary incontinence and walking disability in patients with increased ICP. The patients with positive Alzheimer diagnosis on biopsy did not improve.

Auditory event-related potentials differentiate patients with normal pressure hydrocephalus and patients with concomitant Alzheimer's disease verified by brain biopsy.

We studied 51 patients with clinical symptoms and CT findings suggesting normal pressure hydrocephalus (NPH). Tests included head MRI, auditory event-related potentials (ERPs), thorough neuropsychological testing and intraventricular intracranial 24 h pressure recording and infusion testing. A brain biopsy was also obtained to verify a concomitant dementing process (Alzheimer's disease; AD). Patients were divided into subgroups according to the need of shunt and the biopsy findings, and their ERPs were analysed blindly. The present results suggest that non-invasive ERPs aid in the differentiation of pure NPH from NPH with concomitant AD.

Cell cycle regulators (p21, p53, pRb) in oligodendrocytic tumors: a study by novel tumor microarray technique.

Using the novel tissue microarray technique, we studied immunohistochemical expression of cell cycle regulators p53, p21, pRb in 42 grade II oligodendrogliomas, 16 grade III anaplastic oligodendrogliomas, 10 primary and 4 recidive grade II oligoastrocytomas, 10 grade III oligoastrocytomas and 2 other grade II mixed gliomas. The p53 immunopositivity associated with malignant histology of the tumor (p = 0.01, Mann-Whitney test) and high pRb expression (p = 0.015). The p21 score associated strongly with histological grade (p < 0.001). The immunopositive tumors had a significantly higher rate of proliferation (p = 0.021). The p21 immunopositivity correlated positively with p53 immunopositivity: among the 33 p21 immunopositive tumors 30 (91%) were p53 immunopositive and only 3 were p53 immunonegative (p = 0.017). Patients with p21 immunonegative primary tumors had significantly better prognosis: among them 42 of the 46 (91%) survived, whereas only 18 of the 30 patients (60%) with p21 immunopositive primary tumors survived until the follow-up date (p = 0.0017). Statistical significance was reached in multivariate analysis as well (p = 0.01, exp(B) = 5.5). The pRb immunopositive tumors had higher proliferation rate than immunonegative tumors (p = 0.002). In multivariate variance analysis, comparing the effects of different regulatory proteins on cell proliferation, only the amount of pRb expression reached statistical significance (p = 0.004). In conclusion, the expression of p21 in oligodendrocytic tumors seems to be upregulated by p53 expression which rises with cell proliferation and malignancy as in attempt to halt cell cycle but seems to be overrun by other factors. The amount of p21 expression has independent prognostic significance and could be used in diagnosis to help the difficult evaluation of the malignancy potential of oligodendrogliomas and oligoastrocytomas.

High topoisomerase IIalpha expression associates with high proliferation rate and and poor prognosis in oligodendrogliomas.

The role of molecular markers predicting the prognosis and the selection of patients for further adjuvant therapies is not well established in oligodendroglioma patients. A potential prognostic as well as a therapeutically predictive factor, topoisomerase IIalpha (topoIIalpha), is a molecular target for certain cytotoxic drugs. Its expression has been shown to correlate with the prognosis in a number of different cancers and with the chemosensitivity of cancer cells in vitro. The expression of topoIIalpha was evaluated immunohistochemically in 59 oligodendrogliomas and in 29 mixed gliomas with a predominating oligodendroglioma component by the use of a tissue microarray technique. In the gliomas, the percentage of topoIIalpha immunopositive cells protein expression varied from 0.0 to 49.1% (5.2 +/- 8.3%, mean+/- SD). In oligoastrocytomas, the mean topoIIalpha score was significantly higher in the oligodendroglioma than in the astrocytoma component of the tumour (5.37 +/- 5.58% vs. 1.89 +/- 2.49%, P = 0.018). A significant association was found between the high proportion of topoIIalpha positive cells and high grade of the tumour (P < 0.0001), high tumour proliferation rate (P < 0.0001), p53 overexpression (P = 0.01) and high expression of tumour suppressing retinoblastoma protein (P = 0.023). TopoIIalpha expression was not associated with the age or sex of patient, and the rate of apoptosis. TopoIIalpha expression associated highly significantly with patient prognosis; a significantly higher proportion of patients with low rather than with high topoIIalpha score was alive at the end of the 5-year follow-up (P = 0.03). Cox analysis was used to demonstrate that topoIIalpha had an independent prognostic value for survival (P = 0.034). In conclusion, high topoIIalpha expression characterizes oligodendrogliomas and oligoastrocytomas which are poorly differentiated, have high proliferation rate, and has prognostic value for overall survival of these patients. Therefore, topoIIalpha may be a useful marker for better targeted selection of poor prognosis oligodendroglioma patients for adjuvant therapy.

Thymidine kinase gene therapy for human malignant glioma, using replication-deficient retroviruses or adenoviruses.

Herpes simplex virus thymidine kinase (HSV tk) gene therapy combined with ganciclovir (GCV) medication is a potential new method for the treatment of malignant glioma. We have used both retrovirus-packaging cells (PA317/tk) and adenoviruses (Adv/tk) for gene therapy for malignant glioma. Retrovirus-packaging cells were used for eight tumors in seven patients and adenoviruses were used for seven tumors in seven patients. As a control group, seven tumors in seven patients were transduced with lacZ marker gene 4-5 days before tumor resection. Safety and efficacy of the gene therapy were studied with clinical evaluation, blood and urine samples, MRI follow-up, and survival of the patients. Four patients with adenovirus injections had a significant increase in anti-adenovirus antibodies and two of them had a short-term fever reaction. Frequency of epileptic seizures increased in two patients. No other adverse events possibly related to gene therapy were detected. In the retrovirus group, all treated gliomas showed progression by MRI at the 3-month time point, whereas three of the seven patients treated with Adv/tk remained stable (p < 0.05). Mean survival times for retrovirus, adenovirus, and control groups were 7.4, 15.0, and 8. 3 months, respectively. The difference in the survival times between the adenovirus and retrovirus groups was significant (p < 0.012). It is concluded that HSV tk gene therapy is safe and well tolerated. On the basis of these results further trials are justified, especially with adenovirus vectors.

Association between the density of mossy fiber sprouting and seizure frequency in experimental and human temporal lobe epilepsy.

PURPOSE: If the sprouting of granule cell axons or mossy fibers in the dentate gyrus is critical for the generation of spontaneous seizures in temporal lobe epilepsy (TLE), one could hypothesize that epileptic animals or humans with increased sprouting would have more frequent seizures. This hypothesis was tested by analyzing the data gathered from experimental and human epilepsy. METHODS: In experiment I (rats with "newly diagnosed" TLE), self-sustained status epilepticus was induced in rats by electrically stimulating the amygdala. Thereafter, the appearance of spontaneous seizures was monitored by continuous video-electroencephalography (EEG) until the animal developed two spontaneous seizures and for 11 d thereafter. Rats were perfused for histology, and mossy fibers were stained using the Timm method. In experiment II (rats with "recently diagnosed" TLE), status epilepticus was induced in rats and the development of seizures was monitored by video-EEG for 24 h/d every other day for 60 days. All animals were then perfused for histology. In experiment III (rats with "chronic" TLE), animals were monitored by video-EEG for 24 h/d every other day for 6 months before histologic analysis. To assess mossy fiber sprouting in human TLE, hippocampal sections from 31 patients who had undergone surgery for drug-refractory TLE were stained with an antibody raised against dynorphin. RESULTS AND CONCLUSIONS: Our data indicate that the density of mossy fiber sprouting is not associated with the total number of lifetime seizures or the seizure frequency in experimental or human TLE.

MR imaging of the hippocampus in normal pressure hydrocephalus: correlations with cortical Alzheimer's disease confirmed by pathologic analysis.

BACKGROUND AND PURPOSE: MR studies have shown hippocampal atrophy to be a sensitive diagnostic feature of Alzheimer's disease (AD). In this study, we measured the hippocampal volumes of patients with a clinical diagnosis of normal pressure hydrocephalus (NPH), a potentially reversible cause of dementia when shunted. Further, we examined the relationship between the hippocampal volumes and cortical AD pathologic findings, intracranial pressure, and clinical outcomes in cases of NPH. METHODS: We measured hippocampal volumes from 37 patients with a clinical diagnosis of NPH (27 control volunteers and 24 patients with AD). The patients with NPH underwent biopsy, and their clinical outcomes were followed for a year. RESULTS: Compared with those for control volunteers, the findings for patients with NPH included a minor left-side decrease in the hippocampal volumes (P < .05). Compared with those for patients with AD, the findings for patients with NPH included significantly larger hippocampi on both sides. Although not statistically significant, trends toward larger volumes were observed in patients with NPH who had elevated intracranial pressure, who benefited from shunting, and who did not display cortical AD pathologic findings. CONCLUSIONS: Measurements of hippocampal volumes among patients with a clinical diagnosis of NPH have clear clinical implications, providing diagnostic discrimination from AD and possibly prediction of clinical outcome after shunting.

Prevalence of Alzheimer's disease in patients investigated for presumed normal pressure hydrocephalus: a clinical and neuropathological study.

During 1991-1995, 223 patients were investigated in the Department of Neurosurgery, Kuopio University Hospital because of a clinical and CT diagnosis of NPH. All patients underwent intracranial pressure measurements and were formed into 3 biopsy groups. Group A included incidentally biopsied patients (104 patients, 34 biopsies) seen during 1991-1992; Group B was a prospective study group from 1993-1995 (all 51 patients biopsied); and Group C patients excluded from Group B (68 patients, 34 biopsies) by age and concomitant diseases. A cortical biopsy was taken before intracranial pressure recording altogether in 118 of the 223 patients. The biopsy revealed normal brain tissue in 66 patients. Prevalence of Alzheimer's disease (AD) in biopsied patients was 42% in Group A, 31.3% in Group B and 50% in Group C. A shunt was placed according to pressure measurement in 110 patients; of these, 8 had both AD and raised ICP. Two patients with both AD and raised ICP improved after shunt placement during the first follow-up year, 4 patients deteriorated and the condition of 2 was similar to that before shunting. The frequency of haematomas after biopsy was 2.9% in groups A and C; in Group B patients had no postoperative haematomas. There was no difference in the incidence of complications in patients who had or did not have a biopsy. The relatively high prevalence of AD in patients with NPH may explain the unsuccessful recovery of many patients after shunt placement. Cortical biopsy is an effective and safe method for finding the co-existence of AD and thus improving the diagnosis of NPH and may prevent unnecessary shunt surgery.

CDKN2/p16 predicts survival in oligodendrogliomas: comparison with astrocytomas.

Cyclin-dependent kinase 4 inhibitor (CDKN2/p16) is a cell cycle regulatory protein that has been demonstrated to be inactivated by mutations, deletions or transcriptional silencing during pathogenesis of a variety of human malignancies. We studied the correlation of CDKN2/p16 expression with cell proliferation activity and patient survival in 42 oligodendrogliomas and 36 astrocytomas. CDKN2/p16 expression was frequently decreased in grade II and anaplastic oligodendrogliomas (17/42) where lack of CDKN2/p16 protein predicted poor survival (p = 0.0045). In astrocytomas low CDKN2/p16 expression was associated with high histologic malignancy grade (p = 0.002): CDKN2/p16 protein level was decreased in 9 out of 10 glioblastomas, in 5 out of 9 anaplastic astrocytomas, in 3 out of 10 grade II astrocytomas and in none of pilocytic astocytomas (0/7). Low CDKN2/p16 expression was also associated with high cell proliferation activity (MIB-1 immunocytochemistry: p = 0.004; mitotic index: p = 0.007) and poor patient survival (p = 0.025) in astrocytomas. Low CDKN2/p16 mRNA expression had the same topographic distribution as nuclear CDKN2/p16 immunoreactivity proving for reliability of the immunocytochemical findings. Our results are in agreement with earlier studies demonstrating CDKN2/p16 inactivation during tumorigenesis of astrocytic tumors. Furthermore, our findings suggest that loss of CDKN2/p16 expression may also play an important role in the progression of oligodendrogliomas. According to our findings CDKN2/p16 immunocytochemistry could be used as a tool to identify those oligodendrogliomas and low grade astrocytomas that are likely to progress and have poor outcome, and thus would need more aggressive therapy.

Clinicopathological correlation of cell proliferation, apoptosis and p53 in cerebellar pilocytic astrocytomas.

We have analysed 78 cerebellar pilocytic astrocytomas to assess whether histopathology, cell proliferation, apoptosis rate, p53 immunoreactivity, or flow cytometry could predict their long-term behaviour. Classic pilocytic/microcystic pattern was seen in 62 patients and 16 patients had mixed pattern with an additional non-pilocytic glial component. The overall 5-year survival was 93%, complete resection providing 100% survival. The four patients who died during the follow-up were more than 14 years of age, their primary operation had been incomplete and three of them were mixed variants. In 15 cases the tumour recurred giving a recurrence-free 5-year survival of 77%. The proliferation indices were low: Ki-67MIB-1 (median 2.0%), PCNA (1.2%) and S-phase fraction (4.4%). The Ki-67MIB-1-labelling index was significantly higher in young patients, but did not differ between the classic and mixed variants. Twenty-two per cent of the tumours were aneuploid with a significantly higher S-phase fraction than in diploid tumours. p53 seems to act as ardian of the genome' in pilocytic astrocytomas, because aberrant/increased expression of p53 and aneuploidy associated with enhanced apoptosis. Only patient age (P = 0.01), radicality of the primary operation (P = 0.0001) and histology (classic vs mixed, P=0.008) significantly correlated with survival. The poorer prognosis of the mixed variant suggests that this may represent a distinct entity. Although none of the novel parameters significantly predicted recurrence or survival, they indicate substantial biological variation among cerebellar pilocytic astrocytomas.

Remodeling of neuronal circuitries in human temporal lobe epilepsy: increased expression of highly polysialylated neural cell adhesion molecule in the hippocampus and the entorhinal cortex.

Neuronal loss and axonal sprouting are the most typical histopathological findings in the hippocampus of patients with drug-refractory temporal lobe epilepsy (TLE). It is under dispute, however, whether remodeling of neuronal circuits is a continuous process or whether it occurs only during epileptogenesis. Also, little is known about the plasticity outside of the hippocampus. We investigated the immunoreactivity of the highly polysialylated neural cell adhesion molecule (PSA-NCAM) in the surgically removed hippocampus and the entorhinal cortex of patients with drug-refractory TLE (n=25) and autopsy controls (n=7). Previous studies have shown that the expression of PSA-NCAM is associated with the induction of synaptic plasticity, neurite outgrowth, neuronal migration, and events requiring remodeling or repair of tissue. In patients with TLE, the optical density (OD) of punctate PSA-NCAM immunoreactivity was increased both in the inner and outer molecular layers of the dentate gyrus, compared with controls. The intensity of PSA-NCAM immunoreactivity in the inner molecular layer correlated with the duration of epilepsy, severity of hippocampal neuronal loss, density of mossy fiber sprouting, and astrogliosis. In TLE patients with only mild neuronal loss in the hippocampus, the density of infragranular immunopositive neurons was increased twofold compared with controls, whereas in TLE patients with severe neuronal loss, the infragranular PSA-NCAM-positive cells were not present. In the hilus, the somata and tortuous dendrites of some surviving neurons were intensely stained in TLE. PSA-NCAM immunoreactivity was also increased in CA1 and in layer II of the rostral entorhinal cortex, where immunopositive neurons were surrounded by PSA-NCAM-positive fibers and puncta. Our data provide evidence that synaptic reorganization is an active process in human drug-refractory TLE. Moreover, remodeling is not limited to the dentate gyrus, but also occurs in the CA1 subfield and the entorhinal cortex.

Quantitative 1H nuclear magnetic resonance diffusion spectroscopy of BT4C rat glioma during thymidine kinase-mediated gene therapy in vivo: identification of apoptotic response.

We have investigated the effects of thymidine kinase-mediated gene therapy in a malignant rat BT4C glioma by using 1H nuclear magnetic resonance spectroscopy in vivo. Ganciclovir has been successfully used in thymidine kinase gene therapy as treatment for various experimental malignancies. The cell damaging effect seems to be mediated by apoptosis, optimally leading to eradication of tumor tissue. In this study, we show that ganciclovir treatment of tumors transfected with the herpes simplex thymidine kinase gene causes profound changes in water, metabolites, and macromolecules observable by diffusion spectroscopy. During treatment, a 50% reduction from 0.14 +/- 0.01 x 10(-9) m2/s in the apparent diffusion coefficient of choline-containing compounds can be observed, concomitant with a 219% increase in the apparent diffusion coefficient of the rapidly diffusing water component. These changes are associated with an increase in the relative fraction of this water component from 87 to 94%. The apparent diffusion coefficients of the slowly diffusing water component and macromolecules remain unaltered. The results imply a reduction in cell size and number, a significant increase in intracellular viscosity, and a possible reduction in the hydrodynamic radii of macromolecular components, which are ascribed as biophysical signatures for apoptotic cell death.

Beta-galactosidase gene transfer to human malignant glioma in vivo using replication-deficient retroviruses and adenoviruses.

Both retro- and adenovirus-mediated gene therapy have been suggested as a novel approach to the treatment of malignant brain tumors. However, little information is available about the gene transfer efficiency in human malignant glioma in vivo. We compared the feasibility and safety of retrovirus- and adenovirus-mediated beta-galactosidase gene transfer in human malignant glioma. Beta-galactosidase gene was transferred to 10 patients with malignant glioma via a catheter inserted into the tumor. The catheter was left in place until the tumor resection. To maximize gene transfer efficiency, gene transfer vectors (BAG retroviruses, titer, 6 x 10(5) CFU; and adenoviruses, titer from 3 x 10(8) to 3 x 10(10) PFU) were injected into the tumor via the catheter once a day for three consecutive days, followed by tumor resection 1-2 days later. Tumor was resected in such a way that the catheter was still in place inside the tumor, which permitted accurate histological analysis of the transduced tumors. X-Gal staining for beta-galactosidase activity was used to study gene transfer efficiency and distribution of the marker gene. Beta-galactosidase gene transfer was well tolerated with both vectors. Except for two patients with clear increases in serum adenovirus antibody titers, no adverse tissue responses or systemic complications were noticed in any of the patients. Gene transfer was successful in all patients. Gene transfer efficiency varied between <0.01 and 4% with retroviruses and between <0.01 and 11% with adenoviruses. However, the transgene activity was not evenly distributed in the tumors. Both glioma cells and endothelium in the tumor blood vessels were transduced with retro- and adenovirus vectors. In conclusion, the safety and feasibility of in vivo gene transfer to human malignant glioma was established with retro- and adenovirus vectors. Adenoviruses were more efficient than retroviruses in achieving in vivo gene transfer. Transduction of endothelial cells may have important consequences for the proposed treatment strategies and selection of treatment genes. The results justify clinical gene therapy trials for malignant glioma.

Calretinin-immunoreactive terminals make synapses on calbindin D28k-immunoreactive neurons in the lateral nucleus of the human amygdala.

A double-labeling immunohistochemical procedure and correlated light and electron microscopy were used to examine if calretinin-immunoreactive terminals make synapses on calbindin D28k-positive cells. In the lateral nucleus of the human amygdala, calretinin terminals make symmetric-like synapses on the somata and proximal dendrites of calbindin D28k-labeled cells. Our data provide the first evidence that neurons which contain two different calcium-binding proteins form synaptic contacts with each other in the human amygdala.

Apolipoprotein E genotype and amyloid load in Alzheimer disease and control brains.

We investigated the effect of apolipoprotein E (apoE) genotype on amyloid load in the frontal and cerebellar cortices of 24 patients with definite Alzheimer disease (AD) and 19 controls. Amyloid load was examined by using two methods: 1) acid-extractable amyloid beta-protein (A beta) and insoluble A beta levels of frontal and cerebellar cortices were measured by using enzyme-linked immunosorbent assay, and 2) all types of amyloid plaques and neurofibrillary tangles (NFT) in the frontal cortices were counted after silver staining. Acid-extractable A beta and insoluble A beta levels were higher in AD brains than controls, although there was an overlap between the groups. Acid-extractable A beta and insoluble A beta levels were higher from AD and controls with the apoE epsilon 4 alleles than those without such alleles. However, the differences did not reach statistical significance in AD group. There was no correlation between acid-extractable A beta or insoluble A3 levels and the number of amyloid plaques in AD and control brains. However, insoluble A beta levels correlated positively with the number of NFT in AD brains. Our results show that although apoE epsilon 4 influences the accumulation of A beta, multiple processes may be involved in deposition of A beta in the brain.

Apolipoprotein E (apoE) levels in brains from Alzheimer disease patients and controls.

We measured apolipoprotein E (apoE) level in neutral and acidic pH extracts of the frontal, temporal and cerebellar cortices from patients with definite Alzheimer's disease (AD) and controls, and analyzed the relationship among apoE levels, clinical and neuropathological findings, and apoE genotype. Our data showed that the levels varied in different brain regions being lowest in the frontal cortex and highest in the cerebellum in Ad brains. ApoE levels in neutral pH extracts from the frontal cortex from AD patients were significantly lower than those of controls, and correlated negatively with the number of neurofibrillary tangles. ApoE genotype was not associated with the levels of apoE. There was no correlation between apoE levels and amyloid load or synaptophysin-immunoreactivity in the brain. We conclude that apoE levels are not increased in AD brains. However, apoE levels vary in different brain regions, and local factors related to the synthesis and metabolism of apoE may be crucial in the pathogenesis of AD.

Pseudoexfoliation syndrome with poorly dilating pupil: a light and electron microscopic study of the sphincter area.

BACKGROUND: The study was carried out to examine histological changes in the iris sphincter muscle and surrounding tissue in eyes with pseudoexfoliation syndrome (PXS). METHODS: Seventeen patients with PXS, 14 of them having capsular glaucoma, were enrolled into the study. Iris biopsies were obtained during extracapsular cataract extractions (ECCE) requiring sphincterotomies. Thirteen biopsy specimens underwent histological examination by light microscopy, and four were examined with the electron microscope. Three iris biopsies from cadaver eyes and one obtained during ECCE from a patient with a miotic pupil (no PXS) served as control specimens on light microscopy. Electron microscopic controls included three iris specimens from cadavers. RESULTS: In the light microscopic examination, blood vessel walls were stained with Congo Red in seven of the 13 PXS specimens. In three of these seven specimens the stromal tissue was extensively fibrotized, and in two specimens fibrosis was moderate. Distinct stromal fibrosis was also observed in one and moderate fibrosis in two PXS specimens negative for amyloid. The control specimens were not positive for Congo Red, but stromal tissue was moderately fibrotized in one specimen. Light microscopy did not reveal differences in muscle tissue between PXS and control specimens. Electron microscopically, however, the muscle tissue was fibrotic or disorganized in three PXS specimens and in one control specimen. Fibrils, similar to the fibrillar component of pseudoexfoliation material described in previous studies, were found in intimate association with the capillary basal lamina in all of the PXS specimens showing muscular fibrosis. CONCLUSIONS: These findings support the theory that PXS is associated with amyloid, and in some PXS eyes miosis is connected with degenerative changes both in the stromal tissue and in the muscular layer of the iris.