P11.69.B IDH1/2wildtype gliomas grade 2 and 3 with molecular glioblastoma-like profile have a distinct course of epilepsy compared toIDH1/2wildtype glioblastomas

Background

IDH1/2 wildtype (IDHwt) glioma WHO grade 2 and 3 patients with pTERT mutation and/or EGFR amplification and/or +7/−10 chromosome gain/loss have a similar overall survival time as IDHwt glioblastoma patients, and are both considered glioblastoma IDHwt according to the WHO 2021 classification. However, differences in seizure onset have been observed. This study aimed to compare the course of epilepsy in the two glioblastoma subtypes.

Material and Methods

We analyzed epilepsy data of an existing cohort including IDHwt histologically lower-grade glioma WHO grade 2 and 3 with molecular glioblastoma-like profile (IDHwt hLGG) and IDHwt glioblastoma patients. Primary outcome was the incidence proportion of epilepsy during the disease course. Major secondary outcomes included onset of epilepsy, number of seizure days and antiepileptic drug (AED) polytherapy.

Results

Out of 254 patients, 78% (50/64) IDHwt hLGG and 68% (129/190) IDHwt glioblastoma patients developed epilepsy during the disease course (p=0.121). Epilepsy onset before histopathological diagnosis occurred more frequently in IDHwt hLGG compared to IDHwt glioblastoma patients (90% versus 60%, p<0.001), with a significantly longer median time to diagnosis (3.5 versus 1.3 months, p<0.001). Median total seizure days was also longer for IDHwt hLGG patients (7.0 versus 3.0, p=0.005), and they received more often AED polytherapy (32% versus 17%, p=0.028).

Conclusion

Although the incidence proportion of epilepsy during the entire disease course is similar, IDHwt hLGG patients show a significantly higher incidence of epilepsy before diagnosis and a significantly longer median time between first seizure and diagnosis compared to IDHwt glioblastoma patients, indicating a distinct clinical course.

P04.10 CDKN2A mutational status is associated with venous thromboembolism in patients with glioblastoma

BACKGROUND

Patients with glioblastoma have a high risk of developing venous thromboembolism (VTE). However, the underlying genetic risk factors remain largely unknown. Therefore, the aim of our study was to discover whether genetic aberrations in glioblastoma associate with VTE.

MATERIAL AND METHODS

In this retrospective cohort study, all patients diagnosed with glioblastoma between February 2017 and August 2020 in two hospitals (Leiden University Medical Center and Haaglanden Medical Center) were included (n=341). Targeted DNA next-generation sequencing (NGS) had been performed of all glioblastomas for diagnostic purposes and included tumor mutational status of the genes ATRX, BRAF, CIC, FUBP1, H3F3A, IDH1, IDH2, PIK3CA, PTEN and TP53 and amplification/gain or deletion of BRAF, CDKN2A, EGFR, NOTCH1 and PTEN. Through extensive chart review, we collected data on VTE events (deep vein thrombosis and/or pulmonary embolism) three months before until two years after glioblastoma diagnosis, which were adjudicated by an independent investigator. Patients with cerebral vein thrombosis (n=3) and low quality NGS data (n=1; minimum reads/samples: <1.5M and/or minimum depth: <100 reads) were excluded. Cox regression analysis and competing risk analysis (CICR) were performed to compare patients that developed VTE with patients that did not.

RESULTS

Of the 337 patients, 215 had died, 26 were diagnosed with VTE and 37 were lost to follow-up. CDKN2A deletion was found to associate most significantly with VTE (HR: 2.65, 95%CI: 1.18–5.94, p=0.018). Competing risk analysis confirmed this finding, demonstrating a 12-month adjusted cumulative incidence of 12.7% (95%CI: 7.5–19.3) compared to 5.2% (95%CI: 2.5–9.2) in patients with CDKN2A wild-type (p=0.013). No significant association was found between any of the investigated genes, including CDKN2A deletion, and death.

CONCLUSION

This study demonstrates that CDKN2A deletion is associated with VTE in glioblastoma patients. Therefore, CDKN2A mutational status may be a promising predictor to identify patients with glioblastoma at high risk of VTE, who may benefit from thromboprophylaxis.

Lumbar disc extrusions reduce faster than bulging discs due to an active role of macrophages in sciatica

OBJECTIVE

This retrospective observational histological study aims to associate the size and type of disc herniation with the degree of macrophage infiltration in disc material retrieved during disc surgery in patients with sciatica.

METHODS

Disc tissue of 119 sciatica patients was embedded in paraffin and stained with hematoxylin and CD68. Tissue samples were categorized as mild (0-10/cm2), moderate (10-100/cm2), and considerable (> 100/cm2) macrophage infiltration. All 119 patients received an MRI at baseline, and 108 received a follow-up MRI at 1-year. MRIs were reviewed for the size and type of the disc herniations, and for Modic changes in the vertebral endplates.

RESULTS

Baseline characteristics and duration of symptoms before surgery were comparable in all macrophage infiltration groups. The degree of macrophage infiltration was not associated with herniation size at baseline, but significantly associated with reduction of size of the herniated disc at 1-year post surgery. Moreover, the degree of macrophage infiltration was higher in extrusion in comparison with bulging (protrusion) of the disc. Results were comparable in patients with and without Modic changes.

CONCLUSION

Macrophage infiltration was positively associated with an extruded type of disc herniation as well as the extent of reduction of the herniated disc during 1-year follow-up in patients with sciatica. This is an indication that the macrophages play an active role in reducing herniated discs. An extruded disc herniation has a larger surface for the macrophages to adhere to, which leads to more size reduction.

OS10.1 Survival analysis of IDH wildtype astrocytomas with molecular features of glioblastoma, WHO grade IV

BACKGROUND

Recently, isocitrate dehydrogenase wildtype (IDHwt) lower grade gliomas (LGGs) that have a telomerase reverse transcriptase (TERT) promoter mutation and/or gain of chromosome 7 combined with loss of chromosome 10 and/or epidermal growth factor receptor amplification have been reclassified as IDHwt astrocytomas with molecular features of glioblastoma, WHO grade IV (‘astrocytomas IDHwt, WHO IV’). Survival of these tumors meeting the criteria of these tumors is less well studied. The objective of this study is to compare the overall survival (OS) between the IDHwt astrocytomas, WHO IV and histological glioblastomas (GBMs).

MATERIAL AND METHODS

In this retrospective multicenter cohort study, all adult patients with a newly diagnosed IDHwt LGG (histologically WHO grade II or III) and with molecular data available were selected from the Erasmus MC and the LUMC from October 2002 to April 2019. LGG patients showing contrast enhancement with necrosis on the MRI at the time of histological diagnosis were excluded. Molecular data were determined using a diagnostic NGS panel. A historical cohort of 195 patients with IDHwt GBMs with molecular data available was used to compare OS. OS was measured from the date of the first diagnostic MR scan.

RESULTS

79 IDHwt LGG patients were identified of which 62 patients had molecular features of glioblastoma (‘astrocytomas IDHwt, WHO IV’), 11 patients did not have these molecular features (‘astrocytomas IDHwt, WHO II & III’). In the remaining 6 patients the molecular data were not conclusive (astrocytomas IDHwt, WHO NOS). Patients with astrocytomas IDHwt, WHO IV were slightly older at diagnosis (median age = 57 years) than patients with GBMs IDHwt in the reference cohort or astrocytomas IDHwt, WHO II & III (respectively: median age 55 years, p=0.032 and 47 years, p=0.035). The relatively young age of our GBM IDHwt cohort reflects more extensive molecular testing in younger patients and histologically lower grade tumors. The median OS of astrocytomas IDHwt, WHO IV (23.8 months) was similar to the median OS of GBMs (19.2 months, log-rank test p=0.37). The median OS in 19 patients with only TERT promoter mutations was 16.8 months, similar to GBMs (p=0.94).

CONCLUSION

There is no statistically significant difference between the OS of IDHwt astrocytomas with molecular features of glioblastoma and the OS of true glioblastomas. Grade II and III IDHwt astrocytoma with molecular features of glioblastoma should be designated WHO grade IV. The presence of TERT promoter mutations alone in this histological context also qualifies for this designation.

Dystrophin levels and clinical severity in Becker muscular dystrophy patients

OBJECTIVE

Becker muscular dystrophy (BMD) is characterised by broad clinical variability. Ongoing studies exploring dystrophin restoration in Duchenne muscular dystrophy ask for better understanding of the relation between dystrophin levels and disease severity. We studied this relation in BMD patients with varying mutations, including a large subset with an exon 45-47 deletion.

METHODS

Dystrophin was quantified by western blot analyses in a fresh muscle biopsy of the anterior tibial muscle. Disease severity was assessed using quantitative muscle strength measurements and functional disability scoring. MRI of the leg was performed in a subgroup to detect fatty infiltration.

RESULTS

33 BMD patients participated. No linear relation was found between dystrophin levels (range 3%-78%) and muscle strength or age at different disease milestones, in both the whole group and the subgroup of exon 45-47 deleted patients. However, patients with less than 10% dystrophin all showed a severe disease course. No relation was found between disease severity and age when analysing the whole group. By contrast, in the exon 45-47 deleted subgroup, muscle strength and levels of fatty infiltration were significantly correlated with patients' age.

CONCLUSIONS

Our study shows that dystrophin levels appear not to be a major determinant of disease severity in BMD, as long as it is above approximately 10%. A significant relation between age and disease course was only found in the exon 45-47 deletion subgroup. This suggests that at higher dystrophin levels, the disease course depends more on the mutation site than on the amount of the dystrophin protein produced.

Local injection of autologous bone marrow cells to regenerate muscle in patients with traumatic brachial plexus injury: a pilot study

Objectives

Traumatic brachial plexus injury causes severe functional impairment of the arm. Elbow flexion is often affected. Nerve surgery or tendon transfers provide the only means to obtain improved elbow flexion. Unfortunately, the functionality of the arm often remains insufficient. Stem cell therapy could potentially improve muscle strength and avoid muscle-tendon transfer. This pilot study assesses the safety and regenerative potential of autologous bone marrow-derived mononuclear cell injection in partially denervated biceps.

Methods

Nine brachial plexus patients with insufficient elbow flexion (i.e., partial denervation) received intramuscular escalating doses of autologous bone marrow-derived mononuclear cells, combined with tendon transfers. Effect parameters included biceps biopsies, motor unit analysis on needle electromyography and computerised muscle tomography, before and after cell therapy.

Results

No adverse effects in vital signs, bone marrow aspiration sites, injection sites, or surgical wound were seen. After cell therapy there was a 52% decrease in muscle fibrosis (p = 0.01), an 80% increase in myofibre diameter (p = 0.007), a 50% increase in satellite cells (p = 0.045) and an 83% increase in capillary-to-myofibre ratio (p < 0.001) was shown. CT analysis demonstrated a 48% decrease in mean muscle density (p = 0.009). Motor unit analysis showed a mean increase of 36% in motor unit amplitude (p = 0.045), 22% increase in duration (p = 0.005) and 29% increase in number of phases (p = 0.002).

Conclusions

Mononuclear cell injection in partly denervated muscle of brachial plexus patients is safe. The results suggest enhanced muscle reinnervation and regeneration.

Cite this article: Bone Joint Res 2014;3:38–47.

Typical cluster headache caused by granulomatous pituitary involvement

A young woman had typical cluster headache attacks and a pituitary mass lesion. The headache attacks resolved after transsphenoidal resection of the tumour, which was diagnosed as a granulomatous inflammation. The association between cluster headache and granulomatous enlargement of the pituitary gland has never been described before. This case reinforces the growing evidence that even in typical cases of cluster headache, neuroimaging is mandatory to exclude structural lesions.

A nasal squamous cell carcinoma complicated by a paraneoplastic syndrome consisting of a myositis and anti-Jo-1 autoantibodies

We report a female patient with the clinical features of a Jo-1-syndrome as a paraneoplastic phenomenon secondary to a nasal squamous cell carcinoma.

Associations with autoimmune disorders and HLA class I and II antigens in inclusion body myositis

Whether autoimmune mechanisms play a role in the pathogenesis of inclusion body myositis (IBM) is unknown. Human leukocyte antigen (HLA) analysis in 52 patients, including 17 with autoimmune disorders (AIDs), showed that patients were more likely to have antigens from the autoimmune-prone HLA-B8-DR3 ancestral haplotype than healthy control subjects, irrespective of the presence of AIDs. Patients lacked the apparently protective HLA-DR53 antigen. The results provide further support for an autoimmune basis in IBM.

SDHD mutations in head and neck paragangliomas result in destabilization of complex II in the mitochondrial respiratory chain with loss of enzymatic activity and abnormal mitochondrial morphology

Hereditary head and neck paragangliomas are tumours associated with the autonomic nervous system. Recently, mutations in genes coding for subunits of mitochondrial complex II, succinate-ubiquinone-oxidoreductase (SDHB, SDHC, and SDHD), have been identified in the majority of hereditary tumours and a number of isolated cases. In addition, a fourth locus, PGL2, has been mapped to chromosome 11q13 in an isolated family. In order to characterize phenotypic effects of these mutations, the present study investigated the immunohistochemical expression of the catalytic subunits of complex II (flavoprotein and iron protein), SDH enzyme activity, and mitochondrial morphology in a series of 22 head and neck paragangliomas. These included 11 SDHD-, one SDHB-, two PGL2-linked tumours, and eight sporadic tumours. In the majority of the tumours (approximately 90%), the enzyme-histochemical SDH reaction was negative and immunohistochemistry of catalytic subunits of complex II showed reduced expression of iron protein and enhanced expression of flavoprotein. Ultrastructural examination revealed elevated numbers of tightly packed mitochondria with abnormal morphology in SDHD-linked and sporadic tumours. Immuno-electron microscopy showed localization of the flavoprotein on the remnants of the mitochondrial inner membranes, whereas virtually no signal for the iron protein was detected. These results indicate that the function of mitochondrial complex II is compromised in the majority of head and neck paragangliomas.

Dementia in hereditary cerebral hemorrhage with amyloidosis-Dutch type is associated with cerebral amyloid angiopathy but is independent of plaques and neurofibrillary tangles

Cerebral amyloid angiopathy is frequently found in demented and nondemented elderly persons, but its contribution to the causation of dementia is unknown. Therefore, we investigated the relation between the amount of cerebral amyloid angiopathy and the presence of dementia in 19 patients with hereditary cerebral hemorrhage with amyloidosis-Dutch type. The advantage of studying hereditary cerebral hemorrhage in amyloidosis-Dutch type is that patients with this disease consistently have severe cerebral amyloid angiopathy with minimal neurofibrillary pathology. The amount of cerebral amyloid angiopathy, as quantified by computerized morphometry, was strongly associated with the presence of dementia independent of neurofibrillary pathology, plaque density, or age. The number of cortical amyloid beta-laden severely stenotic vessels, vessel-within-vessel configurations, and cerebral amyloid angiopathy-associated microvasculopathies was associated with the amount of cerebral amyloid angiopathy and dementia. A semiquantitative score, based on the number of amyloid beta-laden severely stenotic vessels, completely separated demented from nondemented patients. These results suggest that extensive (more than 15 amyloid beta-laden severely stenotic vessels in five frontal cortical sections) cerebral amyloid angiopathy alone is sufficient to cause dementia in hereditary cerebral hemorrhage with amyloidosis-Dutch type. This may have implications for clinicopathological correlations in Alzheimer's disease and other dementias with cerebral amyloid angiopathy.

Presence of immunoreactive beta-endorphin in human skin

The production and its induction by ultraviolet radiation (UVR) of proopiomelanocortin (POMC)-derived peptides by keratinocytes has been reported, albeit not consistently. Recently we demonstrated that only under specific culturing conditions human keratinocytes are capable of producing a beta-endorphin (betaE)-like peptide with the characteristics of beta-lipotropin (betaLPH). Here the presence and UV-induction of betaE-immunoreactivity (betaE-IR) in keratinocytes in human skin in vivo was investigated. betaE-IR was detectable by immunohistochemistry in keratinocytes of the follicular matrix and to some extent in cells of sweat ducts, but was absent from epidermal keratinocytes. Absence of betaE-IR was confirmed by radioimmunoassay of HPLC-fractionated extracts of normal epidermis. Repeated exposure to solar-simulated UVR had no effect. This investigation is the first to demonstrate the presence of betaE-immunoreactive material in the follicular matrix of corporal hairs and in duct cells of sweat glands. The possible meaning of these results is discussed.

Diagnostic strategies for the histological examination of muscle biopsy specimens for the assessment of vasculitis in rheumatoid arthritis

For the diagnosis of rheumatoid vasculitis (RV), histological examination of a blindly-taken muscle biopsy is advocated. If fibrinoid necrosis (FN) is observed in one or more tissue sections of the biopsy the diagnosis of RV is confirmed. The diagnostic value of such histological investigation depends on the prevalence of FN in biopsies of RV patients, the number of tissue sections that are investigated, and the sampling design with which the tissue sections are obtained from the biopsy. In this paper we determine the mathematical relation between the sensitivity of the RV diagnosis and these three factors for four different models for the FN distribution in RV biopsies. The goodness-of-fit of these models was assessed by analysing 18 829 tissue sections of the biopsies of 56 patients, among which were 24 (otherwise histologically proven) RV patients. It appeared that the sensitivity was moderate: FN was observed in only 14 out of 24 (58 per cent) muscle biopsies of the RV patients. The prevalence of FN in the tissue sections of those 14 biopsies was low, about 17 per cent according to the best fitting model. We proved that the sampling design, maximizing the minimum distance between tissue sections (equidistant sampling) was optimal, and that with such optimal sampling, examination of about 20 tissue sections was sufficient. With practical sampling designs, however, considerably more tissue sections had to be inspected. FN appeared to cluster in the RV biopsies, and a first-order Markov model satisfactorily described the (auto)correlation between adjacent tissue sections in RV biopsies.

Epidemiology of inclusion body myositis in the Netherlands: a nationwide study

Epidemiologic data on inclusion body myositis (IBM) are scarce, and possibly biased, because they are derived from larger neuromuscular centers. The present nationwide collaborative cross-sectional study, which culminated on July 1, 1999, resulted in identification of 76 patients with IBM and the establishment of a prevalence of 4.9 patients with IBM per million inhabitants in the Netherlands. Several discrepancies suggest that this may be an underestimation. The most frequently identified pitfall in diagnosing IBM was an erroneous diagnosis of polymyositis or motor neuron disease.

[Patient with eosinophilic polymyositis]

In a 36-year-old patient with a severe polymyositis peripheral eosinophilia and abundant infiltration of muscle tissue by eosinophilic granulocytes were observed. Eosinophilic polymyositis was diagnosed. Treatment consisted of high dose prednisone, immunoglobulin and azathioprine, resulting in complete remission of the disease. Idiopathic eosinophilic polymyositis is an uncommon disorder, first described in 1976. The eosinophilic granulocyte is essential in the pathogenesis (by releasing toxic mediators and the production of cytokines), but the cause of the activation is still unknown. Treatment is aimed at immune suppression and consists first of all in administration of prednisone.

Amyloid beta protein (Abeta) starts to deposit as plasma membrane-bound form in diffuse plaques of brains from hereditary cerebral hemorrhage with amyloidosis-Dutch type, Alzheimer disease and nondemented aged subjects

To clarify where and how beta-amyloid begins to deposit in senile plaques, we examined the ultrastructural localization of amyloid beta protein (Abeta) in diffuse plaques of brains with hereditary cerebral hemorrhage with amyloidosis-Dutch type. Alzheimer disease (AD), and from nondemented aged subjects. Serial ultrathin sections of osmium-plastic blocks were immunogold-labeled for Abetax-42 (Abeta42), and sections on grids were observed under the electron microscope (EM) after observing the exact localization of the diffuse plaques in sections on glass slides by the reflection contrast microscope. Abeta42 deposition, which was decollated with gold particles, appeared in 3 forms in all subjects under the EM: 1) Scattered small bundles of amyloid fibrils between cell processes, frequently seen in the densely stained area of diffuse plaques. 2) Scattered small foci of nonfibrillar materials between cell processes as a relatively minor form. 3) Abeta42 on a part of the cell surface plasma membrane of normal appearing cell processes, a major form in weakly immunostained areas. The last form was not associated with degenerative neurites or reactive glia. Abeta42 deposition on the cell surface plasma membrane appears to be an initial event in diffuse plaques, and then it develops into amorphous/fibrillar amyloid between cell processes.

Age-related plaque morphology and C-terminal heterogeneity of amyloid beta in Dutch-type hereditary cerebral hemorrhage with amyloidosis

The evolvement of amyloid beta (Abeta) deposition in the frontal cerebral cortex of 24 patients of increasing age with Dutch-type hereditary cerebral hemorrhage with amyloidosis (HCHWA-D) was studied using end-specific monoclonal antibodies to Abetax-42 (Abeta42) or Abetax-40 (Abeta40) and markers for degenerating neurites. Abeta42 immunostaining revealed parenchymal Abeta deposits with a heterogeneous morphology and distribution, i.e., clouds, fine/dense diffuse, coarse, and homogeneous plaques. Clouds and diffuse plaques were associated with glial Abeta granules. Abeta40 labeling was absent in clouds/fine diffuse plaques, inconsistent and variably intense in dense diffuse/coarse plaques and consistent in homogeneous plaques. In a subset of Abeta40-positive plaques, degenerating neurites--without tauopathy--and/or amyloid cores were observed. Electron microscopy revealed no apparent amyloid fibrils in fine diffuse plaques, small bundles of fibrils in dense diffuse/homogeneous plaques, and amyloid masses in coarse plaques. The parenchymal Abeta pathology was age-related: the ratio of fine to dense diffuse plaques decreased with age, clouds were limited to younger patients; coarse plaques to the oldest old. Homogeneous/cored plaques were present most consistently in older patients. Plaque density did not increase with age. Vascular Abeta deposits stained for both Abeta species, but exclusively Abeta42-positive, presumably recent deposits were also observed. This study suggests that HCHWA-D is a model of plaque evolution in which clouds leave fine diffuse plaques, which may become dense diffuse and ultimately coarse or homogeneous plaques.

Intravascular ultrasound combined with Raman spectroscopy to localize and quantify cholesterol and calcium salts in atherosclerotic coronary arteries

Coronary intravascular ultrasound (IVUS) can assess arterial wall architecture and localize large intravascular deposits, but it does not provide quantitative chemical information, which is essential in the evaluation of atherosclerotic lesions. Previously, it has been shown that Raman spectroscopy can be used to accurately quantify the relative weights of cholesterol, calcium salts, triglycerides, and phospholipids in homogenized arterial tissue. In the present study, we explore some benefits of combining IVUS and Raman spectroscopy to evaluate the intact arterial wall. IVUS images were collected in vitro from human coronary arterial segments in various stages of disease (n=7). The images were divided into radial segments (11 to 28 per image, 332 in total), each of which was classified visually as calcified or noncalcified tissue. The arteries were opened longitudinally, and Raman spectra were collected from locations at 0. 5-mm intervals across the arterial luminal circumference. The spectra were used to calculate the chemical composition of the arterial wall at the examined locations. Generally, locations containing large amounts of calcium salts, as determined with Raman spectroscopy, were classified as calcified with IVUS. However, small calcific deposits (<6% of weight) were not readily detected with IVUS. The amounts and location of cholesterol determined with Raman spectroscopy were correlated closely with the presence of cholesterol observed by histochemistry, but these deposits could not be located accurately by IVUS. The combination of Raman spectroscopy and IVUS applied in vitro provides detailed information about the amount and location of calcific deposits and lipid pools in atherosclerotic plaques. Future advances in optical fiber technology may allow simultaneous collection of Raman spectra and IVUS images through the same catheter in vivo.

Toxicity of Dutch (E22Q) and Flemish (A21G) mutant amyloid beta proteins to human cerebral microvessel and aortic smooth muscle cells

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is characterized by the deposition of amyloid beta protein (Abeta) in cortical and leptomeningeal vessels of patients with Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis, Dutch type. Smooth muscle cells (SMC) from cerebral microvessels (MV) are of particular interest as a site of Abeta-related injury because CAA is much more pronounced in the tunica media of cortical arterioles than meningeal arteries. Patients carrying point mutations at residues 22 (E22Q) and 21 (A21G) of Abeta show severe CAA with various degrees of brain parenchymal Abeta deposition. The purpose of this study was to investigate the effects of 2 mutant E22Q- and A21G-Abeta peptides on MV and aortic SMC. MERHODS: SMC were isolated from human cerebral MV and aorta. Cell morphology, viability, and proliferation as parameters of Abeta toxicity were investigated after 3 days of peptide treatment by trypan blue exclusion and [(3)H]thymidine incorporation.

RESULTS

E22Q-Abeta induced significant decreased cellular proliferation and viability, as well as obvious degeneration of both MV and aortic SMC. A21G-Abeta and wild-type Abeta did not cause significant toxicity, as judged by cell morphology, viability, or cell proliferation, on either type of SMC.

CONCLUSIONS

E22Q-Abeta induced greater toxicity in all parameters than A21G-Abeta and wild-type Abeta with respect to both MV and aortic SMC. A21G-Abeta did not show a significant toxic effect on MV and aortic SMC. This differential effect may be linked to cell type-specific processing and metabolism of mutant forms of Abeta. Mutations in amyloid precursor protein may lead to CAA by different pathogenetic mechanisms or share an unknown property that distinguishes them from wild-type Abeta.

Glioblastoma causing granulocytosis by secretion of granulocyte-colony-stimulating factor

We describe a patient with a glioblastoma multiforme with excessive granulocytosis in the peripheral blood. Shown at both protein and mRNA levels, the tumor produced very high levels of granulocyte-colony-stimulating factor (G-CSF). G-CSF is a growth factor that induces the recruitment of granulocytes. The paraneoplastic phenomenon described here partly mimicked a brain abscess. Production of G-CSF by (brain) tumor cells might be related to the granulocytosis common in malignant disease.

Ultrastructural evidence of early non-fibrillar Abeta42 in the capillary basement membrane of patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type

The C-terminal profile and ultrastructure of small and presumably early capillary amyloid beta protein (Abeta) deposits were investigated in four patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type. The C terminus of the 40 (Abeta40) or the 42 (Abeta42) amino acid form of Abeta was gold labeled in serial, ultrathin sections on glass slides for reflection contrast microscopy and on grids for electron microscopy. In all studied subjects, reflection contrast microscopy revealed capillaries with focal Abeta42 immunolabeling in the absence of Abeta40 labeling. In the adjacent electron microscopic section, Abeta42 labeling was confined to the capillary basement membrane. The majority of Abeta42(+)40(-) deposits showed no amyloid fibrils. Abeta42(+)40(-) deposits were sometimes observed in an unremarkable basement membrane but usually showed increased electron density and reticular structures. A small subset of Abeta42(+)40(-) deposits with basement membrane changes showed few amyloid fibrils. Abeta42(+)40(+) capillary deposits always showed definite fibrils and were larger than Abeta42(+)40(-) capillary deposits. The present findings suggest that in capillaries the accumulation and subsequent polymerization of Abeta42, possibly in conjunction with basement membrane changes, precedes the definite fibril formation with Abeta40.

Correlation between histopathological findings in C-5 and C-6 nerve stumps and motor recovery following nerve grafting for repair of brachial plexus injury

OBJECT

Proximal spinal nerve stumps were used as donor sites for grafts to repair brachial plexus traction lesions. The quality of the stumps was assessed histologically, and its correlation with the strength attained in the target muscle was studied.

METHODS

Four histopathological parameters in frozen tissue sections of 31 C-5 or C-6 nerve stumps were examined by a neuropathologist. The total quantity of myelin was compared with normal values. Also, thick myelinated fibers, fibrosis, and misdirected axons were assessed. Stumps embedded in plastic were used in a morphometric study of myelinated fiber profiles. The fiber density, mean size, and size distribution in five donor stumps were determined; three normal C-5 spinal nerves obtained at autopsy served as controls. Finally, the relative area occupied by fiber profiles and interspace was computed. Linear regression was used as a multivariate analysis, adjusting the outcome of surgical repair for effects of age, interval between trauma and surgery, and graft length. Histopathological examination showed that the total quantity of myelin in donor stumps used for biceps muscle reinnervation was considerably reduced. On morphometric examination the fiber density did not differ significantly between stumps obtained in patients and control stumps obtained at autopsy. However, a significant reduction of the area occupied by myelinated fibers was measured: from 46% in controls to 13% in patients (p < 0.0001). Likewise, a significant reduction was found in the mean fiber size: from 7.4 microm in controls to 3.7 microm in patients (p < 0.0001). The relationship between the myelin quantity in the proximal stump and the grade of biceps muscle recovery was statistically significant (p = 0.02). From the 95% confidence interval it was concluded that the estimated effect of a mean increase of myelinated fibers by 25% almost equals an increase in recovery of one point on the Medical Research Council scale (grade range 0-5).

CONCLUSIONS

Both histopathological and morphometric examination showed a reduction of the quantity of myelin in C-5 or C-6 stumps used as donor sites for grafts. The amount of myelin is significantly correlated with biceps muscle function after nerve grafting. Because it is possible to assess the quantity of myelin by intraoperative examination of frozen sections, this correlation is potentially useful in the decision-making process of whether to use stumps for grafting or to use nerve transfer procedures to restore biceps muscle function.

Analysis of the subcellular localization of huntingtin with a set of rabbit polyclonal antibodies in cultured mammalian cells of neuronal origin: comparison with the distribution of huntingtin in Huntington's disease autopsy brain

Huntington's disease (HD) is a neurodegenerative disorder with a midlife onset. The disease is caused by expansion of a CAG (glutamine) repeat within the coding region of the HD gene. The molecular mechanism by which the mutated protein causes this disease is still unclear. To study the protein we have generated a set of rabbit polyclonal antibodies raised against different segments of the N-terminal, central and C-terminal parts of the protein. The polyclonal antibodies were affinity purified and characterized in ELISA and Western blotting experiments. All antibodies can react with mouse and human proteins. The specificity of these antibodies is underscored by their recognition of huntingtin with different repeat sizes in extracts prepared from patient-derived lymphoblasts. The antibodies were used in immunofluorescence experiments to study the subcellular localization of huntingtin in mouse neuroblastoma NIE-115 cells. The results indicate that most huntingtin is present in the cytoplasm, whereas a minor fraction is present in the nucleus. On differentiation of the NIE-115 cells in vitro, the subcellular distribution of huntingtin does not change significantly. These results suggest that full-length huntingtin with a normal repeat length can be detected in the nucleus of cycling and non-cycling cultured mammalian cells of neuronal origin. However, in HD autopsy brain the huntingtin-containing neuronal intranuclear inclusions can be detected only with antibodies raised against the N-terminus of huntingtin. Thus several forms of huntingtin display the propensity for nuclear localization, possibly with different functional consequences.

Amyloid beta precursor protein-mRNA is expressed throughout cerebral vessel walls

To determine the presence and distribution of cerebrovascular Abeta production we investigated amyloid beta precursor protein (AbetaPP)-mRNA expression by RNA in situ hybridization in patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type, Alzheimer disease and controls. In all subjects, AbetaPP-mRNA was expressed in endothelial cells, smooth muscle cells, adventitial cells and brain pericytes and/or perivascular cells. Meningeal cells also expressed AbetaPP-mRNA. AbetaPP was detected in endothelial cells, smooth muscle cells and adventitial cells. The demonstration of AbetaPP-mRNA at all vascular sites where amyloid formation can occur supports an important contribution of locally derived Abeta to cerebrovascular amyloidosis.

Numerous and widespread alpha-synuclein-negative Lewy bodies in an asymptomatic patient

Lewy bodies (LB) and pale bodies (PB), their putative precursors, can be found in a spectrum of diseases characterized by parkinsonism and/or dementia. Furthermore, LB are occasionally observed in some other neurodegenerative diseases and in normal aging. Classical LB are typically found in the brain stem, especially in the substantia nigra, where these inclusions are associated with neuronal loss and clinical signs of idiopathic Parkinson's disease (PD). The so-called cortical LB occur in the cerebral cortex, amygdala and claustrum with little or no neuronal loss and are clinically associated with dementia in dementia with LB (DLB). We describe a patient without apparent clinical signs of parkinsonism and/or dementia, whose brain contained numerous classical-like LB, pale inclusions with features of PB and transitions between these two. These inclusions had similar immunohistological (ubiquitin positive; neurofilament positive; tau negative) and ultrastructural features as the LB in PD and DLB except for the lack of immunoreactivity for alpha-synuclein. The pons and cerebral cortex showed the highest number of LB, up to 165/1.76 mm2. These numbers were contrasted by the lack of obvious neuronal loss or gliosis. The absence of alpha-synuclein reactivity in the LB in this symptomless patient corroborates the hypothesis that alpha-synuclein accumulation in LB is an important step in neurodegeneration in PD and DLB, but tones down the role of alpha-synuclein in LB formation in general. This patient seems to represent a new variant in the spectrum of diseases associated with LB.

Microvasculopathy is associated with the number of cerebrovascular lesions in hereditary cerebral hemorrhage with amyloidosis, Dutch type

BACKGROUND AND PURPOSE

Microvascular changes such as microaneurysms and fibrinoid necrosis have been found in the presence of cerebral amyloid angiopathy (CAA). These CAA-associated microvasculopathies (CAA-AM) may contribute to the development of CAA-associated hemorrhages and/or infarcts, hereafter referred to as "cerebrovascular lesions." Hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D) is an autosomal dominant form of CAA, in which the amyloid angiopathy is pathologically and biochemically similar to sporadic CAA associated with aging and Alzheimer disease. To determine the significance of CAA-AM for CAA-associated cerebrovascular complications, we investigated the association between CAA-AM and cerebrovascular lesions in HCHWA-D patients.

METHODS

In a previous autopsy study we semiquantitatively scored CAA-AM in 29 HCHWA-D patients. In the present study we reviewed clinical charts and autopsy protocols of these same patients. We investigated whether CAA-AM was associated with age at death, number of cerebrovascular lesions, duration of clinical illness, hypertension, and atherosclerosis.

RESULTS

An association was found between CAA-AM and the number of cerebrovascular lesions (P = 0.009). The presence of microaneurysmal degeneration was most strongly associated with the number of cerebrovascular lesions (P < 0.001). In addition, we found an association between atherosclerosis and the CAA-AM score (P = 0.047). Hypertension was not associated with CAA-AM.

CONCLUSIONS

Our findings support previous reports suggesting an important role of secondary microvascular degenerative changes in CAA-associated cerebrovascular lesions and suggest an aggravating effect of systemic atherosclerosis, but not hypertension, on the evolution of CAA-AM. These findings may be of relevance to understanding cerebrovascular complications of sporadic or Alzheimer disease-associated CAA.

Fatal cerebral oedema associated with primary dengue infection

Encephalopathy associated with dengue fever is considered to be a rare condition in adults. We describe a patient with a primary dengue infection who, in the absence of overt signs of dengue shock syndrome, died due to progressive cerebral oedema. Autopsy findings demonstrated loss of integrity of cerebral vascular endothelium and involvement of complement activation.

Very long chain acyl-coenzyme A dehydrogenase deficiency with adult onset

Very long chain acyl-coenzyme A (acyl-CoA) dehydrogenase (VLCAD) deficiency is a severe disorder of mitochondrial beta-oxidation in infants. We report adult onset of attacks of painful rhabdomyolysis. Gas chromatography identified strongly elevated levels of tetradecenoic acid, 14:1(n-9), tetradecadienoic acid, 14:2(n-6), and hexadecadienoic acid, 16:2(n-6). Palmitoyl-CoA and behenoyl-CoA dehydrogenase in fibroblasts were deficient. Muscle VLCAD activity was very low. DNA analysis revealed compound heterozygosity for two missense mutations in the VLCAD gene. The relatively mild clinical course may be due to residual enzyme activity as a consequence of the two missense mutations. Treatment with L-carnitine and medium chain triglycerides in the diet did not reduce the attacks of rhabdomyolysis.

['Inclusion body'-myositis]

In 3 patients, a 72-year-old man, a 62-year-old man and a 73-year-old woman with weakness of respectively the quadriceps femoris, the finger flexors and the pharyngeal muscles, the diagnosis of 'inclusion body myositis' was made. This is a rare, slowly progressive skeletal muscle disorder which is more common in men and after the age of fifty. The activity of serum creatine kinase is often 2-5 times the highest normal value. The electromyogram pattern is myopathic, but can also display neuropathic changes (exclusively). Inclusion body myositis is often misdiagnosed, which can lead to an inappropriate treatment or approach. A frozen muscle biopsy is needed to make cryostat sections for demonstration of myositis with rimmed vacuoles.

Secondary microvascular degeneration in amyloid angiopathy of patients with hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D)

Various secondary microvascular degenerative and inflammatory alterations may complicate cerebral amyloid angiopathy (CAA) and contribute to the morbidity of CAA-associated stroke. We have investigated the severity of CAA-associated microangiopathy in a genetically determined Dutch form of CAA (HCHWA-D) that has major similarities to the type of CAA that more commonly occurs with aging or Alzheimer's disease (AD). The presence and extent of the following vascular abnormalities was assessed: (1) hyalinization/fibrosis, (2) microaneurysm formation, (3) chronic (especially lymphocytic) inflammation, (4) perivascular multinucleated giant cells/granulomatous angiitis, (5) macrophages/histiocytes within the vessel wall, (6) vessel wall calcification, (7) fibrinoid necrosis, and (8) mural or occlusive thrombi. (Of these, calcification of CAA-affected vessel walls has, to our knowledge, been described in only a single patient with CAA-associated cerebral hemorrhage.) Some of the changes, such as histiocytes in blood vessel walls and the relationship of vascular hyalinosis to amyloid beta/A4 protein deposition, were highlighted by immunohistochemistry. By assessing the numbers of sections in which the changes were present for each case, a 'score' reflective of CAA-associated angiopathy could be obtained. This 'score' was reproducible among several observers. We suggest that it might also be applicable to quantifying severe CAA and related microvascular degenerative changes in patients with AD. beta/A4 immunoreactivity was often sparse and adventitial (or almost absent) in severely hyalinized arterioles and microaneurysms. However, macrophages were prominent in the walls of such vessels and may play a role in the pathogenesis and progression of CAA-related microvasculopathy.

The diagnostic value of perivascular infiltrates in muscle biopsy specimens for the assessment of rheumatoid vasculitis

OBJECTIVE

To determine the diagnostic value of perivascular infiltrates (PVI) in randomly obtained muscle biopsy specimens for the assessment of rheumatoid vasculitis (RV).

METHODS

The number and size of PVIs, defined as the presence of mononuclear or polymorphonuclear cells around > or = 50% of the circumference of a vessel wall, as well as the presence of fibrinoid necrosis were determined in frozen sections of muscle samples of RV patients with histologically confirmed vasculitis in fixed muscle tissue (n = 12). The findings were compared with those observed in frozen sections of muscle biopsy specimens of rheumatoid arthritis (RA) patients not suspected of vasculitis (n = 14) and patients with osteoarthritis (OA) (n = 11). The presence of PVIs and of fibrinoid necrosis were sought in four frozen sections of the muscle biopsy specimen.

RESULTS

PVIs were observed in 75% of the RV patients, which was significantly (p < 0.05) higher than the frequency found in RA (14%) or OA (18%) patients. PVIs with > or = three cell layers were found in 67% of the RV patients and in none of the RA and OA patients (p < 0.05). Fibrinoid necrosis was found in least one of four frozen section in 33% of the RV patients. There was a good intra-observer and inter-observer concordance on the presence of fibrinoid necrosis and of PVIs with > or = three cell layers.

CONCLUSIONS

The assessment of PVIs with > or = three cell layers in a muscle biopsy specimen is a specific and reliable test in discriminating RV from RA without vasculitis. The demonstration in muscle of PVIs with > or = three cell layers is more sensitive than that of fibrinoid necrosis in the diagnosis of RV.

Oligoastrocytomas: a clinicopathological study of 52 cases

Oligoastrocytomas form a poorly defined subgroup of glial tumors, and few clinical series have been reported. We performed a retrospective study to elucidate the histopathological features of these tumors and to relate the clinical signs and symptoms and proliferative potential to survival. Oligoastrocytomas were defined as glial tumors with at least 10% neoplastic astrocytes and 10% neoplastic oligodendrocytes; tumors were graded with the St. Anne-Mayo criteria for astrocytomas and oligodendrogliomas. Proliferative potential was estimated with antibodies against proliferating cell nuclear antigen (PCNA). Median survival of 52 patients (median age, 42 years) was 75 weeks (range 2-703 weeks). Actuarial 1-, 2-, 3-, and 5-year survival rates were 67%, 43%, 40%, and 29%, respectively. For 15 patients with grade 3 and 33 with grade 4 lesions (St. Anne-Mayo astrocytoma classification), median survival was 217 and 55 weeks, respectively. For 19 patients with grade 2 and 33 with grade 3 lesions (St. Anne-Mayo oligodendroglioma classification), median survival was 305 and 55 weeks, respectively. Interobserver agreement between three experienced neuropathologists on identification of astrocytes, oligodendrocytes, and unclassifiable cells was low, indicating considerable subjectivity in the histopathological diagnosis. Median PCNA labeling indices correlated with tumor grade, but individual values varied so widely within grades that they had no predictive value for survival. In a multivariate analysis, symptoms of increased intracranial pressure and microvascular proliferation were independently associated with poor prognosis. The biological behavior of subgroups appeared to be distinctly less aggressive than that of 'pure' astrocytomas of similar grade. Better histopathological definition of oligoastrocytomas and improved assessment of percentages of constituent cell types may allow more accurate prognosis.

Association of vascular amyloid beta and cells of the mononuclear phagocyte system in hereditary cerebral hemorrhage with amyloidosis (Dutch) and Alzheimer disease

Arterial and arteriolar amyloid-beta (A beta) deposition in hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) and Alzheimer disease (AD) cerebral amyloid angiopathy (CAA) were studied as to morphology, extent, and association with mononuclear phagocyte system (MPS) cells using A beta, a-smooth muscle actin, and monocyte/macrophage marker (HLA-DR, CD68, CD11c, CD45) immunohistochemistry. The HCHWA-D/AD arterial/arteriolar media showed compact A beta deposits, first appearing at the media/adventitia junction, and concomitant smooth muscle loss. Only HCHWA-D CAA featured (a) severe involvement of larger arteries and (b) arterioles showing a single or double ring of radial A beta surrounding compact A beta. Radial A beta appeared to develop at the media/adventitia junction. Monocyte/macrophage marker-positive foci/cells co-localized with HCHWA-D arterial A beta. Focal HLA-DR/CD11c positivity was observed at the media/adventitia junction of AD/HCHWA-D arteries in the absence of local A beta, but not in controls. Monocyte/macrophage marker positivity co-localizing with radial A beta appeared continuous with perivascular cells and microglia clustering perivascularly. These results suggest that (a) MPS cells are topographically associated with HCHWA-D arterial A beta and radial arteriolar A beta, and (b) HLA-DR/CD11c immunoreactivity may appear at the media/adventitia junction prior to A beta. The latter finding and the assumed formation of radial A beta at the media/adventitia junction may relate to involvement of the abluminal basement membrane in CAA pathogenesis. The role of MPS cells in this process remains to be established.

Optic nerve glioma mimicking an optic nerve meningioma

The case is described of an optic nerve glioma, mimicking an optic nerve meningioma in a man aged 41 years. CT, MRI and DSA revealed an enhancing tumor surrounding the optic nerve. Histopathologic examination of the removed optic nerve revealed a centrally located glioma surrounded by normal optic nerve fibres.

[A patient with Creutzfeldt-Jakob disease following treatment with human growth hormone]

In a 39-year old woman Creutzfeldt-Jakob disease was diagnosed. More than twenty years prior to the first clinical symptoms she had been treated with human pituitary growth hormone. After four months of illness she died of Creutzfeldt-Jakob disease, as was shown by the post-mortem finding of spongiform encephalopathy immunochemically positive for abnormal prion protein. The patient represented the first case of Creutzfeldt-Jakob disease associated with the use of human growth hormone in the Netherlands.

Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D): II--A review of histopathological aspects

Cerebral amyloid-beta (A beta) angiopathy is the histopathological hallmark of hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D). A beta deposits are found mainly in the cerebral and cerebellar meningocortical blood vessels and as plaques throughout the cerebrocortical gray matter. A beta deposition in arteries and arterioles starts at the junction of media and adventitia and proceeds to involve the media causing degeneration of the vascular smooth muscle cells. Cerebrocortical arterioles often show one or two layers of radial A beta around a layer of homogenous A beta that replaces the media. Degenerating neurites, reactive astrocytes and microglial cells may surround cerebrocortical angiopathic arterioles and capillaries, probably in reaction to invasion of the perivascular neuropil by A beta fibrils. Furthermore, clusters of coarse extracellular matrix deposits may be found near A beta-laden cerebrocortical arterioles. The amyloid-associated proteins, cystatin C, and beta PP colocalize diffusely with Dutch vascular A beta, whereas HLA-DR immunoreactivity is found only in the periphery of the diseased vessel wall. The latter phenomenon may be related to the presence of perivascular cells. Angiopathic blood vessels frequently show structural changes. The relation of the described pathology to the development of hemorrhage, infarction and leukoencephalopathy needs further elucidation.

Cortical tissue of patients with hereditary cerebral hemorrhage with amyloidosis (Dutch) contains various extracellular matrix deposits

BACKGROUND

Hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) and Alzheimer's disease (AD) have certain clinical and histopathologic features in common; both are characterized by cerebral amyloid beta deposits. Extracellular matrix (ECM) components have been demonstrated in plaques and in vascular amyloid of AD, suggesting a causative relation.

EXPERIMENTAL DESIGN

We studied the immunohistochemical expression of the ECM components collagen type I, III, and IV, heparan sulfate proteoglycan (HSPG), laminin, and fibronectin in cortical tissue of six HCHWA-D patients, two AD patients, and five controls.

RESULTS

The vasculature of control patients and the noncongophilic vessels in HCHWA-D and AD patients stained for all ECM components, with the exception of collagen type I in part of the capillaries. The media of normal larger vessels stained for collagen type I and III and fibronectin; a similar pattern was found in the vascular amyloid in HCHWA-D and AD patients. The plaques in HCHWA-D and AD reacted for HSPG and weakly for collagen III and IV and laminin. Furthermore, with the exception of anti-collagen type I, all anti-ECM Ab decorated coarse deposits clustered in the vicinity of thick-walled, amyloid-laden vessels in HCHWA-D patients; these deposits were not spatially related to amyloid beta-positive plaques.

CONCLUSIONS

This study demonstrates the presence of ECM components in the main pathologic features of HCHWA-D and as perivascular deposits. The observed distribution of matrix molecules is partly different from AD. The ECM may well be essential for the evolvement of the pathology of HCHWA-D.

Application of chromosome 16 markers in the differential diagnosis of neuronal ceroid-lipofuscinosis

Accurate diagnosis of neuronal ceroid lipofuscinosis (NCL) is important for a correct prognosis of the disease and for genetic counseling. Up to now, no direct diagnostic test has been available for NCL. The clinical diagnosis is made on the basis of symptoms, neurophysiological, neuroradiological, and specific lipopigment pattern data. Recent advances in the genetics of NCL have enabled us to use polymorphic DNA markers linked to the CLN1 and CLN3 loci as a tool in the differential diagnosis of NCL. We have applied genetic analysis with polymorphic DNA markers flanking the CLN3 gene on chromosome 16 to two consanguineous families in which NCL occurs. In the first family, which is of Turkish extraction, two patients suffering from a protracted form of juvenile NCL previously had been diagnosed with juvenile NCL. Haplotypes from this family indicate that the patients and their healthy sibling are haplo-identical, suggesting that this protracted form of juvenile NCL is not linked to the CLN3 locus. In the second family, which is of Moroccan origin, one patient suffers from the early juvenile variant of NCL (Lake-Cavanagh). In this family, the patient and one of the healthy siblings have identical haplotypes, excluding linkage of early juvenile NCL to the CLN3 locus on 16p12.1-11.2. Therefore, these cases from different populations demonstrate that haplotype analysis can be used as an additional method to exclude the diagnosis of juvenile NCL.

Hereditary cerebral hemorrhage with amyloidosis (Dutch): a model for congophilic plaque formation without neurofibrillary pathology

Plaque-like lesions and amyloid angiopathy were investigated in the frontal cerebral cortex of four patients with hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D), using immunohistochemical [antibodies to beta amyloid protein (A beta), beta protein precursor (beta PP), synaptophysin, ubiquitin (UBQ), cathepsin D, paired helical filaments (PHF) and glial fibrillary acidic protein (GFAP)], enzymehistochemical (acid phosphatase) and silver [methenamine silver (MS) and Palmgren] staining methods. Whereas A beta- and MS-positive diffuse plaques were found in all patients, only the three older patients showed neuritic or congophilic plaques, which were acid phosphatase and cathepsin D positive and contained beta PP-, synaptophysin- and UBQ-positive, but PHF-negative neurites. These plaques were surrounded by reactive astrocytes. Similar immuno- and enzymereactivity was found around congophilic blood vessels. Thus, apart from neuronal degeneration in a subset of plaque-like lesions and around blood vessels, this study shows an age-related morphology of the plaques in HCHWA-D, corresponding to that in Down's syndrome (DS), with the difference that neurofibrillary (NF) pathology is absent in HCHWA-D in contrast to DS. HCHWA-D may be considered as a model for congophilic plaque formation not associated with NF pathology.

Microglia in diffuse plaques in hereditary cerebral hemorrhage with amyloidosis (Dutch). An immunohistochemical study

In hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) beta/A4 amyloid deposition is found in meningocortical blood vessels and in diffuse plaques in the cerebral cortex. Diffuse plaques putatively represent early stages in the formation of senile plaques. Microglia are intimately associated with congophilic plaques in Alzheimer's disease (AD), but microglial involvement in diffuse plaque formation is controversial. Therefore, we studied the relationship between microglia and diffuse plaques in the cerebral cortex of four patients with HCHWA-D using a panel of macrophage/microglia markers (mAbs LCA, LeuM5, LeuM3, LN3, KP1, OKIa, CLB54, Mac1, Ki-M6, AMC30 and the lectin RCA-1). Eight AD patients, one demented Down's syndrome (DS) patient and four non-demented controls were included for comparison. In controls and HCHWA-D patients ramified or "resting" microglia formed a reticular array in cortical gray and subcortical white matter. Microglial cells in or near HCHWA-D diffuse plaques retained their normal regular spacing and ramified morphology. In AD/DS gray matter more microglial cells were stained than in controls and HCHWA-D patients. Intensely immunoreactive microglia with enlarged cell bodies and short, thick processes clustered in congophilic plaques. In contrast to the resting microglia, these "activated microglia" strongly expressed class II major histocompatibility complex antigen, HLA-DR, and were AMC30-immunoreactive. These findings support the view that microglia play a role in the formation of congophilic plaques but do not initiate diffuse plaque formation. Another finding in this study is the presence of strong monocyte/macrophage marker immunoreactivity in the wall of cortical congophilic blood vessels in HCHWA-D.

Co-localization of beta/A4 and cystatin C in cortical blood vessels in Dutch, but not in Icelandic hereditary cerebral hemorrhage with amyloidosis

Based on the recent discovery of co-localization of beta/A4 and cystatin C in cortical blood vessels of patients with cerebral hemorrhages due to sporadic amyloid angiopathy and patients with Alzheimer's disease we investigated the presence of these two proteins in the cortical blood vessels of patients suffering from hereditary cerebral hemorrhage with amyloidosis of the Dutch (n = 11) and the Icelandic (n = 2) type. The brains of three patients with sporadic cerebral amyloid angiopathy were also investigated. Blood vessels of the Dutch patients clearly showed immunostaining with beta/A4 as well as with cystatin C antibodies, whereas the blood vessels of Icelandic patients showed only staining with cystatin C. In one of the three sporadic amyloid angiopathy patients co-localization was shown as well. The co-localization of mutated beta/A4 with normal cystatin C in the Dutch patients suggests that cystatin C deposition occurs secondarily to beta/A4 deposition. This is probably also the case in sporadic amyloid angiopathy and Alzheimer's disease. Cystatin C deposition may play a role in the development of cerebral hemorrhages and leukoencephalopathy.

Morphology of cerebral plaque-like lesions in hereditary cerebral hemorrhage with amyloidosis (Dutch)

We studied the presence and morphology of plaque-like lesions in the frontal cortex of six patients, aged 40 to 76 years, with hereditary cerebral hemorrhage with amyloidosis--Dutch type (HCHWA-D), using beta/A4 immuno-, silver, Congo red and thioflavin S staining. Two types of beta/A4 immunoreactive and Congo red-negative plaques were detected. The first type was composed of argyrophilic fibrous material in periodic acid-methenamine silver (PAM) and modified Bielschowsky staining and lacked silver-stained degenerating neurites. Therefore, this type of plaque has the same staining properties as the diffuse plaque described in Alzheimer's disease, Down's syndrome and nondemented elderly. The second type of plaque, occurring only in the three oldest patients and numerically increasing with age, consisted of a spherical non-argyrophilic area of granular texture with a rim of PAM-positive material. The PAM-positive fibrous material of both types of plaques was mingled with coarser and compact, irregular-shaped argyrophilic structures in the oldest patient. The described plaques did not show bright fluorescence with thioflavin S staining. These results indicate, that the morphology of plaques, encountered in HCHWA-D, is diverse and changes with age.

Interphase cytogenetics: a new tool for the study of genetic changes in brain tumors

Interphase cytogenetics is the application of nonradioactive in situ hybridization with chromosome-specific DNA probes to interphase nuclei. In this study, interphase cytogenetics was used to investigate 66 primary brain tumors (33 gliomas, 30 meningiomas, and three medulloblastomas) for numerical chromosomal aberrations of chromosomes 1, 6, 7, 10, 11, 17, 18, X, and Y. Of the 33 gliomas (17 astrocytomas grades II, III, and IV, five oligoastrocytomas, seven oligodendrogliomas, and four ependymal tumors), 22 were near diploid, while the remaining 11 showed a significant triploid or tetraploid component. The predominant specific aberrations in gliomas were an over-representation of chromosome 7 (13 cases) and an under-representation of chromosome 10 (16 cases). These changes were observed in grade III and grade IV astrocytomas, as well as in oligodendrogliomas. Other frequent numerical changes were a gain of chromosome 17 (six cases) and a loss of chromosome 18 (seven cases). This loss of chromosome 18 seemed relatively specific for gliomas with an oligodendroglial component (six cases). Only two of 33 gliomas displayed no genetic abnormality with the probes used. Seven patients with astrocytomas died of their brain tumor during the clinical follow-up period. Their astrocytomas did not show a different chromosomal constitution compared to the other gliomas. For the meningiomas, the probe panel was extended with a probe specific for chromosome 22. Loss of chromosome 22 was obvious in 21 of the 30 meningiomas, and was the sole abnormality in 11 meningiomas; in the other 10, this loss was associated with other chromosomal changes. Five of these tumors with additional aberrations were recurrent or atypical meningiomas. It is suggested that interphase cytogenetics can contribute to a better understanding of the biological behavior of these tumors and possibly result in better insights into prognosis and strategies for therapy.

Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).

Expression of a normal and variant Alzheimer's beta-protein gene in amyloid of hereditary cerebral hemorrhage, Dutch type: DNA and protein diagnostic assays

Amyloid fibrils deposited in cerebral vessel walls in Dutch patients with hereditary cerebral hemorrhage with amyloidosis (HCHWA-D) are formed by polymerization of a 39-residue peptide similar to the beta-protein of Alzheimer's disease, Down syndrome, sporadic cerebral amyloid angiopathy and normal aging. Sequence analysis of genomic DNA in HCHWA-D patients demonstrated a point mutation, cytosine for guanine at position 1852 of the precursor beta-protein gene, which causes a single amino acid substitution (glutamine for glutamic acid) corresponding to position 22 of the amyloid protein. The normal allele was also present in these patients. To examine the expression of normal and variant beta-protein alleles in HCHWA-D we analyzed all the tryptic peptides obtained from several amyloid fractions from leptomeningeal vascular walls. Amino acid sequence of two peptides (T3a and T3b) with identical amino acid composition revealed that T3a had glutamine and T3b had glutamic acid at position 22. Thus both the normal and variant Alzheimer's beta-protein alleles are expressed in vascular amyloid in HCHWA-D and may be detected by tryptic peptide mapping. Moreover, we have developed a diagnostic assay for high risk populations and prenatal evaluation that is based on the existence of the mutation.