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Biomedical subjects

J Palo

Publications and source records attributed to J Palo.

At least 55 records · Page 3Linked to original sources

The aetiology of dizziness and how to examine a dizzy patient.

Dizziness embraces various sensations of spatial disorientation. A common symptom, it has been experienced by at least one third of the population by the age of 65. Peripheral causes include disorders of the labyrinth and vestibular nerve such as Ménière's disease, benign paroxysmal positional vertigo, acute vestibulopathy (vestibular neuronitis) and acoustic neuroma. The most common lesions of the central nervous system that cause dizziness are infratentorial ischaemia, mechanical trauma, multiple sclerosis and cerebellar atrophy. Other aetiological factors include intoxications, psychogenic causes, cervical problems and cardiovascular diseases. The history and physical examination are the cornerstones of the search for the cause of dizziness. The most valuable otological methods are electronystagmography and audiometry. Of the clinical neurophysiological methods, brainstem auditory evoked potentials are more useful than electroencephalography. Computed tomography and magnetic resonance imaging should be used when a CNS disorder is suspected.

Dizziness↗

Finnish type of familial amyloidosis: cosegregation of Asp187----Asn mutation of gelsolin with the disease in three large families.

Familial amyloidosis of Finnish type (FAF) is one of the familial amyloidotic polyneuropathy (FAP) syndromes, a group of inherited disorders characterized by extracellular accumulation of amyloid and by clinical symptoms and signs of polyneuropathy. FAF, an autosomal dominant trait, belongs to those rare monogenic disorders which occur with increased frequency in the Finnish population: only single FAF cases have been reported from other populations. In most types of FAP syndromes the accumulating protein is a transthyretin variant. However, recent evidence has suggested that the amyloid peptides in FAF are related to gelsolin, an actin modulating protein. The gelsolin fragments isolated from at least one patient with amyloidosis have been reported to have an amino acid substitution, with asparagine replacing aspartic acid at position 187 of the plasma gelsolin. In this study allele-specific oligonucleotides were used to analyze three large FAF families with multiple affected individuals as well as healthy family members. We found the corresponding G-A mutation in nucleotide 654 of the plasma gelsolin gene to cosegregate with the disease. The result was confirmed by sequencing and strongly suggests that the mutation has caused all the FAF cases of these families. Since the disease is clustered in restricted areas on the southern coast of Finland, this mutation most probably causes the majority, if not all, of FAF cases in Finland.

Amyloidosis↗

Amyloid protein in familial amyloidosis (Finnish type) is homologous to gelsolin, an actin-binding protein.

Familial amyloidosis, Finnish type, is clinically characterized by cranial neuropathy and lattice corneal dystrophy. It is an autosomal dominant form of systemic amyloidosis with small deposits of congophilic material occurring in most tissues, particularly in association with blood vessel walls and basement membranes. Amyloid fibrils were extracted from the kidney of patient VUO, and rabbit antiserum raised against the 12 kDa purified amyloid subunit displayed strong immunohistochemical reactivity with the amyloid deposits. The amino terminal sequence of this 12 kDa amyloid protein (ATEVPVSWESFNNGD) showed homology with gelsolin (or actin depolymerizing factor), a 93 kDa plasma protein. The amyloid peptide is a degradation product, starting at position 173, of the gelsolin molecule.

Actins↗

Elevated levels of serum dolichol in aspartylglucosaminuria.

Slightly elevated serum dolichol levels have so far been demonstrated only in alcoholics. We now report two diseases with exceptionally high serum dolichol levels. They are autosomal, recessively inherited lysosomal storage diseases, aspartylglucosaminuria (AGU) and mannosidosis. In 16 patients with AGU the mean serum level of total dolichols (457 +/- 43 ng/ml) was more than two-fold when compared to healthy controls (170 +/- 4 ng/ml). In two patients with mannosidosis the levels were almost two-fold. The percentage distribution of the dolichol homologues with 18, 19 or 20 isoprene units did not differ between the patients and controls. The inclusion of an additional control group excluded the possible influence of mental retardation and imparied moving ability on the results. Elevated serum dolichols in patients with lysosomal storage diseases may reflect a disturbance in lysosomal function and serve as a diagnostic marker. The biochemical mechanisms leading to this phenomenon remain to be established.

Acetylglucosamine↗

CT findings in neuronal ceroid lipofuscinoses.

Forty patients suffering from neuronal ceroid lipofuscinosis, 33 of the juvenile type (JNCL) and 7 of the infantile type (INCL), underwent a brain CT. All INCL patients showed severe atrophic changes which were most pronounced supratentorially and in the brainstem. The white matter was hypodense and markedly reduced and the cortical gray matter was quite thin in the oldest patients. The CT signs appeared early and can be used in differential diagnosis. In the JNCL group, CT findings were normal under the age of nine, but in the older patients (n = 28) atrophic changes were detected in all but two. Both supra- and infratentorial atrophy was detected and the severity of the alterations increased with age. No abnormal densities in the brain parenchyma were detected on CT. The severity of the cerebellar atrophy correlated positively with disturbances in motor functions, balance, co-ordination and EEG.

Adolescent↗

Leukocyte glutamate dehydrogenase and CSF amino acids in late onset ataxias.

Leukocyte glutamate dehydrogenase (GDH) activity was measured in 11 healthy control subjects, 16 neurological controls, 12 patients with dominant late onset ataxia, 15 patients with sporadic late onset ataxia and 8 with alcoholic cerebellar ataxia. Serum hexosaminidase activity was also determined in ataxic patients. Concentrations of free amino acids were determined in the lumbal CSF of 16 neurological controls, 8 patients with late onset ataxia and 5 with alcoholic ataxia. Mean total GDH activity was reduced significantly in dominant (p less than 0.05) and sporadic (p less than 0.01) cerebellar ataxia, while the heat-labile form was decreased significantly (p less than 0.01) only in sporadic ataxia. All GDH activities were within normal range in patients with alcoholic ataxia. The serum hexosaminidase activities were also within reference range in all patient groups. The CSF concentrations of alanine, glycine, methionine and valine were significantly elevated and those of GABA and glutamate were normal in patients with late onset ataxia as compared to neurological controls. The most significant (p less than 0.01) increase was found for methionine. The amino acid levels of patients with alcoholic ataxia did not differ from those of the controls. The results suggest that GDH activity is only partially decreased in some ataxic patients and that altered amino acid metabolism may be reflected in the CSF.

Adult↗

Leukocyte glutamate dehydrogenase and CSF amino acids in late onset ataxias.

Leukocyte glutamate dehydrogenase (GDH) activity was measured in 11 healthy control subjects, 16 neurological controls, 12 patients with dominant late onset ataxia, 15 with sporadic late onset ataxia and 8 with alcoholic cerebellar ataxia. Serum hexosaminidase activity was also determined in ataxic patients. Concentrations of free amino acids were determined in the lumbal CSF of 16 neurological controls, 8 patients with late onset ataxia and 5 with alcoholic ataxia. Mean total GDH activity was reduced significantly in dominant (p less than 0.05) and sporadic (p less than 0.01) cerebellar ataxia, while the heat-labile form was decreased significantly (p less than 0.01) only in sporadic ataxia. All GDH activities were within normal range in patients with alcoholic ataxia. The serum hexosaminidase activities were also within reference range in all patient groups. The CSF concentrations of alanine, glycine, methionine and valine were significantly elevated and those of GABA and glutamate were normal in patients with late onset ataxia as compared to neurological controls. The most significant (p less than 0.01) increase was found for methionine. The amino acid levels of patients with alcoholic ataxia did not differ from those of the controls. The results suggest that GDH activity is only partially decreased in some ataxic patients and that altered amino acid metabolism may be reflected in the CSF.

Adult↗

Huntington disease in Finland: linkage disequilibrium of chromosome 4 RFLP haplotypes and exclusion of a tight linkage between the disease and D4S43 locus.

The question about heterogeneity of Huntington disease (HD) at the DNA level can be approached by analyzing the RFLP haplotypes formed by several RFLP loci of the diseased chromosome in different populations. In genetically isolated populations such as Finland, it is further possible to use this approach to test the hypothesis of a single mutation enriched in this population demonstrating an exceptionally low prevalence of HD. In this study covering 70% of all diagnosed HD cases in Finland, linkage disequilibrium of RFLP haplotypes of D4S10 and D4S43 loci polymorphisms was found. This phenomenon, not so far reported in any other population, could support the hypothesis of one ancestor HD mutation in the Finnish population. Despite the lower heterozygosity obtained with some RFLP markers, the proportion of individuals receiving informative DNA test results did not significantly differ from that reported in more mixed populations. In one HD family we established a recombination event between HD and the D4S43 locus, an event which can be highly useful in the more precise mapping of the HD gene.

Chromosome Mapping↗

Amyloid in familial amyloidosis, Finnish type, is antigenically and structurally related to gelsolin.

Immunohistochemical studies of six patients with familial amyloidosis, Finnish type, showed that their amyloid deposits did not react with polyclonal antibodies against the amyloid proteins of other, established forms of systemic or cerebral amyloidosis. However, strong immunoreactivity was observed with rabbit antiserum raised against a low molecular weight purified amyloid subunit isolated from one of the patients. This immunoreactivity was abolished by absorption with the low molecular weight amyloid fraction. The amino terminal sequence of the amyloid protein subunit was homologous to gelsolin, an actin-modulating protein, and the amyloid deposits in tissues reacted with a monoclonal antibody against gelsolin. These studies show that the amyloid protein in familial amyloidosis, Finnish type, is not related to previously identified forms of amyloid, including prealbumin (transthyretin) variants, but represents a novel amyloidogenic protein related to gelsolin, a plasma and cytoplasmic protein.

Actins↗

White matter low attenuation on CT in Alzheimer's disease.

White matter low attenuation (WMLA) was seen on CT in 19.7% of 61 patients with probable Alzheimer's disease. Presence of WMLA was associated with higher age, more severe degree of dementia, and increased CSF/serum albumin ratio, but not with cardiovascular disorders. WMLA on CT might be related to minor vascular events, or Alzheimer patients with WMLA could even constitute their own subtype.

Aged↗

Dolichol and dolichyl phosphate in the neuronal ceroid-lipofuscinoses and other diseases.

Although, compared to age-matched control samples, nonphosphorylated dolichols are significantly increased in the cerebral cortex of children with the late infantile and juvenile types of neuronal ceroid-lipofuscinosis (NCL), dolichyl phosphates are increased to a much greater extent in infantile, late infantile, and juvenile forms of this disease group. Dolichyl phosphates in the cerebral cortex, expressed as a percentage of the combined nonphosphorylated and phosphorylated compounds, ranged from 59 to 85 (mean 71) in NCL, whereas in the non-NCL disease group the range is 18-36 (mean 25). This marked proportional increase in dolichyl phosphates is not unique to NCL but is also found in the brain of GM1-gangliosidosis and Tay-Sachs disease patients. In the liver from NCL patients, dolichyl phosphates are not a major proportion of the total dolichol compounds (1-9%). However, in the kidney and heart, dolichyl phosphates are again markedly increased, and this is associated with large storage of ceroid. Although to a lesser extent than in NCL, dolichols and dolichyl phosphates are significantly increased over levels in age-matched control samples in the temporal cortex in Alzheimer disease. Our interpretation of these results is that storage in secondary in secondary lysosomes in NCL and the gangliosidoses leads to a decrease in the catabolism of dolichyl phosphate compounds in the Golgi saccules or primary lysosomes.

Alzheimer Disease↗

A follow-up study of very low field MRI findings and clinical course in multiple sclerosis.

Seventy-three consecutive patients with definite multiple sclerosis (MS) were examined with very low field (0.17 and 0.02 tesla) magnetic resonance imaging (MRI) of the brain. Fifty-seven patients were examined a second time after 6 months, 41 patients a third time after 1 year, and 25 patients a fourth time after 2 years. The initial finding was abnormal in 57/73 patients (78%). The number of lesions increased with age, duration of disease, and increasing disability. Plaques were more numerous in progressive than in remitting MS. Of the patients with abnormal MRI 65% had more than 3 lesions, and in 82% lesions were smaller than 2.5 cm in diameter. After follow-ups of 1 year and 2 years the size of MRI lesions remained unchanged in 55% and 64%, respectively. Unchanged plaque numbers were found in 72% and 60%. Unchanged MRI was most common among patients with remitting MS who were in a stable phase. Decrease in size and disappearance of plaques correlated well with clinical remissions. Increase in size was rare even during relapses. New plaques could appear during all phases of clinical course although they reflected better a relapse of remitting or progressive disease.

Adult↗

The value of CT and very low field MRI in the etiological diagnosis of dizziness.

A total of 79 dizziness patients were examined by either computed tomography (CT), or very low field magnetic resonance imaging (MRI), or both. In most cases, the patients were selected for the neuroimaging because preliminary clinical examination had suggested central nervous system (CNS) involvement. Abnormal CT or MRI findings with probable clinical relevance to the etiology of dizziness were obtained in 34%. The most common abnormalities were atrophy, infarction, and demyelination.; 29% of the CT scans and 40% of the MRI showed relevant abnormalities. The present results emphasize the diagnostic usefulness of head CT and MRI when dizziness of CNS etiology is suspected.

Adult↗

Oligoclonal immunoglobulin bands in cerebrospinal fluid of patients with Alzheimer's disease and vascular dementia.

We examined serum and cerebrospinal fluid (CSF) of 16 patients with Alzheimer's disease (AD), 28 patients with vascular dementia (VD), their age-matched controls and multiple sclerosis (MS) patients in order to evaluate the humoral immune response within the central nervous system both quantitatively and qualitatively. Intra-blood-brain barrier (BBB) protein synthesis was calculated by CSF IgG index. The presence of oligoclonal banding (OCB) was investigated with agarose isoelectric focusing (IEF) followed by immunoblotting with antihuman IgG. No patient with AD and only 4 patients with VD had slightly elevated IgG indexes, and no statistically significant differences in the indexes were found between the two groups. No bands were found in the CSF of AD patients but 3 VD patients had OCB in both serum and CSF. One VD patient had bands in serum but no bands in CSF. No kappa or lambda free light chains were found in those demented patients with demonstrable bands in the CSF and serum. No OCB were found in control sera and CSF. For comparison, the majority of patients with MS had OCB in CSF. Thus, no consistent increase of intrathecal protein synthesis was found in patients with AD and VD. Methodological differences explain at least part of the conflicting results published earlier.

Aged↗

EEG in the differential diagnosis between Alzheimer's disease and vascular dementia.

Demented patients with Alzheimer's disease (AD) (n = 67), multi-infarct dementia (MID) (n = 77) and probable vascular dementia (PVD) (n = 45) were studied with electroencephalography (EEG). All patients underwent a routine EEG examination and quantitative EEG was recorded from 14 patients with AD, 20 with MID, and 12 with PVD. The patient groups did not differ in regard to sex, age, education, or degree of dementia. Diffuse abnormality of EEG increased in AD, while driving response to photic stimulation and the mean frequency of background activity decreased in all groups with increasing degree of dementia. In quantitative EEG, the percentage of alpha power decreased and those of theta and delta power increased relative to the degree of dementia. Focal abnormalities, and irritative (spikes and/or sharp waves) and slow wave paroxysms were more common in MID than in AD. Patients with different types of dementia did not differ significantly in regard to diffuse abnormality, occurrence of driving response, mean background frequency, or parameters of quantitative EEG. The mean frequency of background activity and the degree of diffuse abnormality correlated with central and cortical atrophy, white matter low attenuation seen on computed tomography, and with neuropsychological findings.

Adult↗