PubMed Health⌕ Search

Biomedical subjects

A Paetau

Publications and source records attributed to A Paetau.

At least 19 recordsLinked to original sources
PubMed2006

Cerebroretinal microangiopathy with calcifications and cysts.

BACKGROUND: Extensive cerebral calcifications and leukoencephalopathy have been reported in two rare disorders Coats plus and leukoencephalopathy with calcifications and cysts. In the latter, a progressive formation of parenchymal brain cysts is a special feature, whereas Coats plus is characterized by intrauterine growth retardation, bilateral retinal telangiectasias and exudations (Coats disease), sparse hair, and dysplastic nails without cyst formation. METHODS: We identified 13 patients, including two pairs of siblings, with extensive cerebral calcifications and leukoencephalopathy. We reviewed clinical, ophthalmologic, radiologic and neuropathologic data of seven deceased patients and studied five patients prospectively. RESULTS: Eleven patients were small for gestational age; the other symptoms emerged from infancy to adolescence. All patients had neurologic symptoms including seizures, spasticity, dystonia, ataxia, and cognitive decline. Progressive intracerebral calcifications involved deep gray nuclei, brainstem, cerebral and cerebellar white matter, and dentate nuclei and were accompanied by diffuse white matter signal changes and, in five patients, cerebral cysts. Eleven patients had retinal telangiectasias or angiomas. Additional features were skeletal and hematologic abnormalities, intestinal bleeding, and poor growth. Neuropathologic examination showed extensive calcinosis and abnormal small vessels with thickened, hyalinized wall and reduced lumen. CONCLUSIONS: Our data suggest that Coats plus syndrome and leukoencephalopathy with calcifications and cysts belong to the same spectrum. The primary abnormality seems to be an obliterative cerebral angiopathy involving small vessels, leading to dystrophic calcifications via slow necrosis and finally to formation of cysts and secondary white matter abnormalities.

Adolescent↗
PubMed2005

Independent component analysis to proton spectroscopic imaging data of human brain tumours.

In proton magnetic resonance spectroscopic imaging (1H MRSI), the recorded spectra are often linear combinations of spectra from different cell and tissue types within the voxel. This produces problems for data analysis and interpretation. A sophisticated approach is proposed here to handle the complexity of tissue heterogeneity in MRSI data. The independent component analysis (ICA) method was applied without prior knowledge to decompose the proton spectral components that relate to the heterogeneous cell populations with different proliferation and metabolism that are present in gliomas. The ability to classify brain tumours based on IC decomposite spectra was studied by grouping the components with histopathology. To this end, 10 controls and 34 patients with primary brain tumours were studied. The results indicate that ICA may reveal useful information from metabolic profiling for clinical purposes using long echo time MRSI of gliomas.

Algorithms↗
PubMed2005

Cerebral amyloid angiopathy in a 95+ cohort: complement activation and apolipoprotein E (ApoE) genotype.

There is growing evidence that in Alzheimer's disease (AD) amyloid beta-protein (Abeta) triggers a chronic inflammatory reaction in cerebral amyloid plaques, including complement proteins. Abeta also accumulates cerebrovascularly in age- and AD-associated cerebral amyloid angiopathy (CAA). We investigated complement proteins in CAA in a population-based series using histological and immunohistochemical staining methods. The 74 subjects, aged 95 years or more, had undergone clinical neurological examination and apolipoprotein E (ApoE) genotyping. The brains had been studied for AD post-mortem, allowing us to relate the histopathological findings to clinical and genetic conditions. CAA with congophilic amyloid was found in 36/74 individuals (48.6%). The vascular amyloid deposits immunoreacted with antibodies to Abeta and complements 3d (C3d) and 9 (C9). The positivity in complement stains increased with growing severity of CAA (P = 0.001). The presence of CAA associated with ApoE epsilon4 (P = 0.0005) and overrepresentation of epsilon4 among those with moderate or severe vs. mild CAA (P = 0.03) was demonstrated. The presence of CAA associated with dementia (P = 0.01), which was contributed by both epsilon4+ (P = 0.02) and epsilon4- (P = 0.06) subjects. Our study shows that complement proteins are deposited in the affected vessels in Abeta-associated CAA. They may solely represent the cerebral Abeta- burden associated to inflammatory stimuli, or signal a contribution in the clearance of cerebral Abeta, thereby contributing to the events associated with evolution of clinical dementia. Our results demonstrate a strong association between CAA and ApoE epsilon4 as well as dementia and suggest that the contribution of CAA to dementia is largely independent of ApoE epsilon4.

Aged, 80 and over↗
PubMed2004

Ezrin expression in tissue microarray of primary and recurrent gliomas.

Malignant progression, infiltrative growth pattern and recurrencies after surgery are characteristic features of diffuse gliomas. Ezrin is a membrane-cytoskeleton linker protein expressed in several types of neoplasms. In experimental models, increased ezrin expression correlates with invasion of malignant glioma cells. We studied ezrin expression and its correlation with patient survival in 229 primary and recurrent astrocytomas (WHO grades II-IV), oligodendrogliomas (II-III) and oligoastrocytomas (II-III) of 113 patients. Ezrin expression as evaluated by immunohistochemistry and immunoblotting was detected in all studied glioma types. Staining intensity and number of immunoreactive cells correlated with increasing malignancy of astrocytomas and oligoastrocytomas (P = 0.001). Ezrin expression was strongest in astrocytomas (P = 0.006). Also oligodendrogliomas were positive for ezrin. High ezrin expression in primary gliomas correlated with shorter time to recurrence (P < 0.05) and poor overall survival (P < 0.05) of the patients. Ezrin expression increased during progression of the tumours (P < 0.05). However, ezrin was not an independent prognostic factor. The results of this study show that ezrin expression is associated with progression of gliomas and correlates with histological cell type and WHO tumour grade.

Adolescent↗
PubMed2003

A distinct phenotype of distal myopathy in a large Finnish family.

OBJECTIVES: The authors carried out clinical, histopathologic, immunocytochemical, electrophysiologic, and imaging investigations and molecular genetic analysis in seven patients with distal myopathy belonging to a Finnish family. RESULTS: The disease showed autosomal dominant inheritance. Age at onset ranged from 32 to 45 years. The first symptoms for referral were clumsiness with the hands and frequent stumbling from a steppage gait. Muscle weakness was characterized by early involvement of the small muscles of the hands, gluteus medium, and both anterior and posterior muscle compartments of the legs. The disease progressed to involve other intrinsic muscles of the hands, as well as the forearm muscles, triceps and infraspinatus, and proximal lower limbs. Asymmetry of muscle involvement was common. EMG showed myopathic features, serum CK was normal or slightly elevated, and muscle biopsy showed many rimmed vacuoles and dystrophic changes. There was no evidence of linkage to Welander distal myopathy or tibial muscular dystrophy loci. CONCLUSION: These patients may have a distinct distal myopathy. Genome-wide scan is undertaken in order to identify the disease locus.

Adult↗
PubMed2003

Histopathological differences of myotonic dystrophy type 1 (DM1) and PROMM/DM2.

Muscle biopsy findings in DM2 have been reported to be similar to those in DM1. The authors used myosin heavy chain immunohistochemistry and enzyme histochemistry for fiber type differentiation on muscle biopsies. Their results show that DM2 patients display a subpopulation of type 2 nuclear clump and other very small fibers and, hence, preferential type 2 fiber atrophy in contrast to type 1 fiber atrophy in DM1 patients.

Adult↗
PubMed2003

Central nervous system aspergillosis in allogeneic stem cell transplant recipients.

Invasive aspergillosis (IA) is relatively common in allogeneic stem cell transplant (SCT) recipients. Although lungs are the most common site, central nervous system (CNS) involvement is also observed in this setting. We have retrospectively studied 14 cases of CNS aspergillosis found in a cohort of 455 allogeneic SCT recipients (incidence 3%). All patients, except one, had experienced acute graft-versus-host disease treated with high-dose methylprednisolone, and eight patients (57%) had also received ATG. The median time to the diagnosis of CNS aspergillosis was 124 days (range 49-347 days) from SCT. Pulmonary aspergillosis had been diagnosed earlier in four patients (29%). The most common initial symptoms of CNS aspergillosis were convulsions, hemiparesis, and mental alteration. Neuroradiological studies revealed single (two patients) or multiple (seven patients) focal lesions of 0.2-9 cm in diameter. Despite clinical suspicion in many patients, a confirmed diagnosis of CNS aspergillosis was made during life in only one patient. A total of 12 patients (86%) received amphotericin B. Despite therapy, all patients died 0-27 days (median seven days) after the initial CNS symptoms. CNS aspergillosis is not uncommon in allogeneic SCT recipients. Clinical manifestations are usually dramatic and progress quickly. Earlier and more effective treatment of IA is needed to prevent dissemination of infection into the CNS.

Adolescent↗
PubMed2003

Pure quadriceps myopathy in two sisters.

The authors carried out a clinical, laboratory and muscle computed tomographgy CT follow-up study of 18-21 years on two sisters affected by quadriceps myopathy (QM). The onset in the fourth decade was a weakness in the thighs. During the follow-up study, the patients showed only vasti muscles involvement, normal creatine kinase (CK) levels, myopathic muscle biopsy and electromyography (EMG) and normal membrane protein expression on immunocytochemical analysis. Therefore, all muscle pathologies known to have quadriceps involvement as a leading feature have been ruled out. We conclude that our patients have pure QM with probable autosomal recessive inheritance.

Biopsy↗
PubMed2002

Axial myopathy--an unrecognised entity.

Axial myopathy (AM) is a rare neuromuscular disorder characterised by selective involvement of the spinal muscles with a bent spine and/or drooping head as leading clinical features. We here report the results of clinical, histopathological, MRI, molecular genetics and electrophysiological investigations carried out on six patients affected by pure axial myopathy. Symptoms appeared within an age range of 35 to 56 years. The first symptoms were difficulty in keeping the trunk and head in an upright position. Both bent spine and dropped head were reduced in a supine position. The disease was slowly progressive. Muscle strength examination and muscle imaging revealed involvement of the spinal and neck extensor muscles only. Serum CK was normal to slightly increased. EMG and muscle biopsy specimens obtained from spinal muscles showed an advanced chronic myopathic pattern. We conclude that axial myopathy may be much more common than previously thought, because gradual progression of cervical kyphosis may often be explained as a feature of normal ageing or as an associated sign of several neurological disorders and vertebral degeneration diseases.

Aged↗
PubMed2001

Adult-onset autosomal recessive ataxia with thalamic lesions in a Finnish family.

OBJECTIVE: To describe an unusual kindred with adult-onset ataxia and thalamic lesions detected by brain MRI. METHODS: The authors characterized clinical, laboratory, and pathologic features of the disease and sought linkage to previously recognized ataxia loci. RESULTS: Two sisters and a brother developed progressive ataxia, dysarthria, mild cognitive impairment, and sensorimotor neuropathy at age 30, combined with epilepsy in one sibling. MRI showed symmetric thalamic lesions, changes in brainstem gray matter, and white matter changes in the cerebellum. Autopsy in one of the patients revealed neuronal degeneration with a peculiar vacuolar change in thalamus, probably representing transsynaptic degeneration in response to deafferentation. Neuronal and secondary tract degeneration was observed in the spinal cord, cerebellum, and brainstem suggesting a spinocerebellar degeneration. The disorder appears to be transmitted as an autosomal recessive trait. Genetic and sequence analysis of the FRDA gene and comprehensive laboratory examinations excluded Friedreich's ataxia and other similar recessive diseases. CONCLUSION: Adult-onset recessive ataxia with bilateral thalamic lesions in this family may represent a distinct hereditary spinocerebellar ataxia.

Adult↗
PubMed2001

Gain of chromosome 3 and loss of 13q are frequent alterations in pituitary adenomas.

Genetic changes underlying the tumorigenesis of pituitary adenomas (PA) are poorly characterized. To search for characteristic genomic imbalances involved in PA, we examined 38 cases: 12 hormone-secreting (HS) and 26 non-functioning (NF) PA, by comparative genomic hybridization. The most frequent DNA copy number change in both kinds of tumors was loss of 13q. Gains of chromosomes 3, 7 and 14, 6p, and 20q were more frequent in HSPA than in NFPA. These data indicate that the 13q region may harbor tumor suppressor genes determining the tumorigenesis of PA and gain in chromosome 3 may be related to hormone secretion. These findings provide a basis to search for candidate diagnostic markers of HSPA.

Adenoma↗
PubMed2001

Adverse long-term effects of brain radiotherapy in adult low-grade glioma patients.

OBJECTIVE: To study the long-term effects of radiotherapy on cognitive function in adult patients operated on for low-grade glioma. METHODS: A cohort of 160 patients who underwent surgery for low-grade gliomas of cerebral hemisphere between 1980 and 1992 in a single institution serving a defined population was studied. At a mean follow-up time of 7 years, 28 of the 101 patients who had postoperative irradiation (and no second surgery or chemotherapy) were still alive and eligible for MRI and neuropsychological study. Twenty-three of 59 patients who did not have radiotherapy, second surgery, or chemotherapy were alive and eligible at a mean of 10 years. RESULTS: The group that had postoperative irradiation performed significantly worse than the group that did not in cognitive tests. This difference was not accounted for by histologic diagnosis; location, extent of removal, or progression of the tumor; or any patient factor. Leukoencephalopathy was more severe in the group that had postoperative irradiation than in the group without radiotherapy, and correlated to poor memory performances only in the postoperative radiotherapy group. Average Karnofsky performance scale score was significantly lower in the group that had postoperative irradiation than in the group that did not. CONCLUSION: In adults with low-grade glioma, postoperative radiotherapy poses a significant risk of long-term leukoencephalopathy and cognitive impairment.

Adult↗
PubMed2001

ATP, phosphocreatine and lactate in exercising muscle in mitochondrial disease and McArdle's disease.

We studied exercise-induced changes in the adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels in the skeletal muscle of mitochondrial patients and patients with McArdle's disease. Needle muscle biopsy specimens for biochemical measurement were obtained before and immediately after maximal short-term bicycle exercise test from 12 patients suffering from autosomal dominant and recessive forms of progressive external ophthalmoplegia and multiple deletions of mitochondrial DNA (adPEO, arPEO, respectively), five patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) 3243 A-->G point mutation, and four patients with McArdle's disease. Muscle ATP and PCr levels at rest or after exercise did not differ significantly from those of the controls in any patient group. In patients with mitochondrial disease, muscle lactate tended to be lower at rest and increase more during exercise than in controls, the most remarkable rise being measured in patients with adPEO with generalized muscle symptoms and in patients with MELAS point mutation. In McArdle patients, the muscle lactate level decreased during exercise. No correlation was found between the muscle ATP and PCr levels and the respiratory chain enzyme activity.

Adenosine Triphosphate↗
PubMed2001

Variant Alzheimer disease with spastic paraparesis: neuropathological phenotype.

Variant Alzheimer disease (varAD) is clinically characterized by the combination of presenile dementia with spastic paraparesis and is caused by certain mutations of the presenilin 1 (PS-1) gene. We now present the unusual neuropathological phenotype of varAD as seen in 5 affected members of the original Finnish family with a genomic deletion encompassing exon 9 of the PS-1 gene. Their primary and association cortices and hippocampus showed a profusion of eosinophilic, roundish structures with distinct borders termed "cotton wool" plaques (CWPs). The CWPs were immunoreactive for Abeta42/43 but weakly or not at all for Abeta40 isoforms of the amyloid beta peptide (Abeta). They were devoid of a congophilic core, and fibrillar amyloid could not be identified within them by electron microscopy. Confocal microscopy showed reduced density of axons within individual CWPs and only few CWP-related PHF-tau-positive dystrophic neurites. CWPs were particularly numerous in the medial motor cortex representing the lower extremities, and degeneration of the lateral corticospinal tracts was observed at the level of the medulla oblongata and the spinal cord. In addition to the predominant CWPs, variable numbers of diffuse and cored plaques were found in the cerebral cortex. Diffuse and non-neuritic cored amyloid plaques but no CWPs occurred in the cerebellum. In conclusion, varAD in this Finnish family is distinct from classic AD because of the degeneration of lateral corticospinal tracts, predominance of CWPs devoid of fibrillar amyloid cores in the cerebral cortex, and presence of non-neuritic amyloid plaques in the cerebellum.

Alzheimer Disease↗
PubMed2001

Evolution of cerebral tumor necrosis factor-alpha production during human ischemic stroke.

BACKGROUND AND PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is detected in ischemic brain cells in experimental animal models and is believed to play an important role in apoptosis. However, the natural expression of TNF-alpha during human stroke is not known. METHODS: We examined TNF-alpha immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) in brain samples of stroke victims (n=16) after variable survival (15 hours to 18 days). Systemic TNF-alpha content from a separate cohort including severe or lethal stroke cases (n=26) was also assayed. RESULTS: Neuronal TNF-alpha was demonstrated from 0.6 to 5.4 days after the onset of stroke symptoms, peaking bilaterally during days 2 and 3. Bilateral glial TNF-alpha immunoreactivity was detected during the acute phase, with the astrocytic TNF-alpha expression dominating in later phases and persisting contralaterally to the infarct in more matured phases (17 to 18 days). Invading inflammatory cells were TNF-alpha immunopositive beginning on the third day. Besides, vascular wall structures showed immunoreactivity sporadically. TNF-alpha levels were mostly nondetectable in peripheral blood. TUNEL labeling and TNF-alpha staining overlapped, although not completely, during the first days. CONCLUSIONS: The data support the hypothesis that TNF-alpha may be involved both in the acute propagation of inflammatory processes and cell death and possibly in the more delayed reconstitutive processes of human ischemic stroke.

Adult↗
PubMed2000

In situ hybridization detection of human herpesvirus 6 in brain tissue from fatal encephalitis.

A 23-month-old girl died after 2 days' illness with rash, fever, and convulsions. Neuropathologic findings were consistent with viral hemorrhagic encephalitis in pontine tegmentum and medial thalamic areas. Human herpesvirus 6 (HHV-6) DNA was detected in pontine nuclei by in situ hybridization. In addition, polymerase chain reaction for HHV-6 of serum and paraffin-embedded pontine tissue was positive, and serology indicated an acute primary infection. This is the first case showing HHV-6 DNA in the brain cells of an immunocompetent patient with acute encephalitis.

Brain↗
PubMed2000

Variant Alzheimer's disease with spastic paraparesis and cotton wool plaques is caused by PS-1 mutations that lead to exceptionally high amyloid-beta concentrations.

We describe 3 new families affected by Alzheimer's disease with spastic paraparesis. In affected individuals, including the earliest known patient with this clinical syndrome, neuropathological examination revealed large "cotton wool" plaques similar to those we have previously described in a Finnish family. In the families in which DNA was available, presenilin-1 mutations were observed. Transfection of cells with these mutant genes caused exceptionally large increases in secreted Abeta42 levels. Furthermore, brain tissue from individuals with this syndrome had very high amyloid-beta concentrations. These findings define the molecular pathogenesis of an important subgroup of Alzheimer's disease and have implications for the pathogenesis of the disease in general.

Alzheimer Disease↗