Predictive and preimplantation genetic testing for Huntington's disease and other late onset dominant disorders: not in conflict but complementary.
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Age of Onset↗
Biomedical subjects
R Dom
Publications and source records attributed to R Dom.
Prediction of psychological functioning one year after the predictive test for Huntington's disease and impact of the test result on reproductive decision making.
For people at risk for Huntington's disease, the anxiety and uncertainty about the future may be very burdensome and may be an obstacle to personal decision making about important life issues, for example, procreation. For some at risk persons, this situation is the reason for requesting predictive DNA testing. The aim of this paper is two-fold. First, we want to evaluate whether knowing one's carrier status reduces anxiety and uncertainty and whether it facilitates decision making about procreation. Second, we endeavour to identify pretest predictors of psychological adaptation one year after the predictive test (psychometric evaluation of general anxiety, depression level, and ego strength). The impact of the predictive test result was assessed in 53 subjects tested, using pre- and post-test psychometric measurement and self-report data of follow up interviews. Mean anxiety and depression levels were significantly decreased one year after a good test result; there was no significant change in the case of a bad test result. The mean personality profile, including ego strength, remained unchanged one year after the test. The study further shows that the test result had a definite impact on reproductive decision making. Stepwise multiple regression analyses were used to select the best predictors of the subject's post-test reactions. The results indicate that a careful evaluation of pretest ego strength, depression level, and coping strategies may be helpful in predicting post-test reactions, independently of the carrier status. Test result (carrier/ non-carrier), gender, and age did not significantly contribute to the prediction. About one third of the variance of post-test anxiety and depression level and more than half of the variance of ego strength was explained, implying that other psychological or social aspects should also be taken into account when predicting individual post-test reactions.
Adult↗
Recovery of corticosteroid-induced changes in contractile properties and morphology of rat diaphragm.
Treatment with the fluorinated steroid triamcinolone (TR) induced type IIb fiber atrophy and the contractile profile of a slow muscle in rat diaphragm. In contrast, the nonfluorinated steroid prednisolone (PR) caused myogenic changes without fiber atrophy, and increased fatigability. The aim of the present study was to investigate the extent to which these changes were reversed 2 mo after discontinuation of treatment. Adult rats were randomly assigned to receive saline, PR 1.25 or 5 mg/kg, or TR 0.25, 0.5, or 1 mg/kg, intramuscularly daily during 4 wk. Administration of TR resulted in severe loss of body weight and dose-dependent mortality. During recovery, body weight in the TR groups increased gradually, still remaining reduced compared with the other groups. Two months after discontinuation of treatment, diaphragm weight was increased in proportion to body weight. Twitch characteristics, maximal tetanic force, force-frequency curve, and fatigue resistance of isolated diaphragm bundles were similar in all groups. Histologic examination of the diaphragm revealed no gross abnormalities in the PR and TR groups. Mild but significant type IIb fiber atrophy was still present in the diaphragm and gastrocnemius muscle of all TR-treated animals. In conclusion, recovery of alterations in morphology of respiratory and peripheral skeletal muscles induced by administration of TR is prolonged.
Animals↗
Effects of acute steroid administration on ventilatory and peripheral muscles in rats.
Occasional case reports have shown that acute myopathy may occur in patients treated with massive doses of corticosteroids. The mechanism of this myopathy is poorly understood. Therefore, 60 male rats were randomly assigned to receive daily injection of saline (C), methylprednisolone (M), or triamcinolone (T) 80 mg/kg/d for 5 d. Nutritional intake, measured daily in 15 animals, showed a significant reduction of food intake in the steroid-treated groups (-50 and -79% in M and T, respectively). This was associated with a similar loss in body weight. In the 45 remaining animals, diaphragm contractility and histopathologic features of several muscles were studied. Weights of respiratory and peripheral muscles were similarly decreased after steroid treatment. Maximal twitches of the diaphragm were lower in the C group (653 +/- 174 g/cm(2)) than in the M group (837 +/- 171 g/cm(2); p < 0.05) and the T group (765 +/- 145 g/cm(2), NS). Half-relaxation time was prolonged in both steroid groups, and time to peak tension was longer with M, whereas tetanic tensions were similar. Steroid treatment also induced a leftward shift of the force-frequency curve at 25 and 50 Hz when compared with saline treatment (p < 0.05). ATPase staining of the diaphragm, scalenus medius, and gastrocnemius showed type IIb fiber atrophy in the steroid groups and also diaphragmatic type IIa atrophy with T, whereas histologic examinations revealed a normal muscular pattern with absence of necrosis. Finally, a pair-fed (PF) study, performed in 18 rats (C, T, and PF), showed that muscle atrophy was considerably less pronounced in PF animals than in T-treated animals. We conclude that (1) short-term treatment with massive doses of steroids induced severe respiratory and limb muscle wasting; (2) both types of steroids induced predominantly type IIb atrophy, resulting in the expected alterations in diaphragm contractile properties; (3) neither steroid caused muscle necrosis; (4) type IIb atrophy was not caused by acute nutritional deprivation alone.
Adrenal Glands↗
Functional and histologic picture of steroid-induced myopathy in chronic obstructive pulmonary disease.
The functional and histologic picture of steroid-induced myopathy was systematically examined in eight patients with chronic obstructive pulmonary disease (COPD) and compared with control patients with COPD matched for age, sex, and degree of airflow obstruction. Steroid-induced myopathy was associated with severe peripheral muscle weakness, quadriceps force being 23 +/- 14 versus 71 +/- 23% in control patients with COPD (p < 0.001). In addition, clear ventilatory muscle weakness was present. PImax was 37 +/- 15 versus 67 +/- 24% in control patients (p < 0.001 ), and PEmax averaged 34 +/- 10 versus 74 +/- 23% (p < 0.001). Vital capacity tended to be slightly reduced compared with that in control patients (69 +/- 21 versus 80 +/- 16%, p = 0.11). The only biochemical abnormalities associated to steroid-induced myopathy were a moderately increased lactic dehydrogenase level (697 +/- 301 versus 421 +/- 128 IU/L, p < 0.001) and an increased creatine excretion in 24-h urine (990 +/- 609 versus 159 +/- 219 mg/24 h, p< 0.001). On quadriceps biopsy steroid-induced myopathy was characterized by increased variation in diameter of fibers, with several angular atrophic fibers and diffuse necrotic and basophilic fibers. In addition, increased amount of connective tissue in between fibers and increased number of subsarcolemmal and central nuclei were present. On ATPase stain diffuse fiber atrophy predominantly affecting fast fibers was present, but there was no indication that atrophy was confined to type IIb fibers in contrast to conventional thinking. On follow-up, survival of patients with steroid-induced myopathy was reduced in comparison with control patients with COPD with similar degree of airflow obstruction (p < 0.025).
Aged↗
Correlations between triplet repeat expansion and clinical features in Huntington's disease.
OBJECTIVE: To investigate possible correlations between the length of the (CAG)n trinucleotide repeat in Hungtington's disease gene IT15 and clinical features (age at onset, symptoms at onset, and mode of progression) in Huntington's disease. DESIGN: In 59 patients with Huntington's disease, the expansion of the (CAG)n trinucleotide repeat was determined and clinical data were obtained retrospectively. SETTING: The Center for Human Genetics, affiliated with a university hospital. PATIENTS: All patients belonged to an initial group of 248 individuals tested in an indirect predictive testing procedure. RESULTS: A good correlation was found between the expansion of the (CAG)n trinucleotide repeat and the age at onset (r = -.71). No correlation was found between the repeat length of the normal allele and the age at onset. No correlations were found between repeat expansion and other clinical features, such as the nature of the symptoms at onset (neurologic, psychiatric/cognitive, or both) and the mode of progression. CONCLUSION: Factors that determine the nature of symptoms at onset and the mode of progression of Huntington's disease seem to be operating independently of the (CAG)n trinucleotide repeat in gene IT15.
Age Factors↗
Chordoma of the lower cervical spine.
Vertebral chordomas are rather rare tumours, especially in the lower cervical region. We present a patient with a C7 vertebral body chordoma and a discussion of pertinent literature is given. Only three C7 chordomas have been reported previously. Diagnosis is sometimes difficult to establish and is based on radiological examinations. Once the histological diagnosis is available, one should aim at a total resection. If this is not possible, adjuvant radiotherapy should be given. For limited cervical lesions, we advise a corporectomy with fusion by an iliac crest graft and osteosynthetic plate stabilisation.
Cervical Vertebrae↗
Corticosteroid treatment and nutritional deprivation cause a different pattern of atrophy in rat diaphragm.
Triamcinolone (TR) causes type IIb fiber atrophy in the rat diaphragm, which is associated with changes in contractile properties. We investigated whether this is a direct effect of TR or the result of an accompanying loss of body and diaphragm weights. For 6 wk, adult rats received saline intramuscularly, TR (0.5 mg/kg im), or nutritional depletion (ND) that resulted in a similar (approximately 40%) reduction in body weight as TR. In these animals, the half-relaxation time of the diaphragm bundles increased, the force-frequency relationship shifted leftward, and the resistance to fatigue was increased. No histological changes were found in the ND diaphragm, in contrast to severe myogenic alterations in the TR diaphragm. Type IIb fiber cross-sectional area (CSA) in the TR diaphragm was reduced by 51%, whereas type I and IIa CSAs were unaffected. In the ND animals, the CSAs of type I, IIa, and IIb fibers were reduced by 31, 33, and 52%, respectively. Similar changes occurred in the deep part of the m. gastrocnemius. In conclusion, myogenic changes and selective type IIb fiber atrophy were caused by TR, whereas ND induced generalized fiber type atrophy without histological changes.
Adrenal Cortex Hormones↗
[Gait disorders and repeated falls in Steele-Richardson-Olszewski syndrome].
Progressive supranuclear palsy (syndrome of Steele-Richardson-Olszewski) represents one of the neuro-degenerative diseases, difficult to distinguish from other forms of parkinsonism. Although uncommon, the syndrome should be included in the differential diagnosis of recurrent falls in the elderly, especially in cases of parkinsonism presenting with axial rigidity and associated with gaze paralysis and/or poor response to L-dopa-therapy. The diagnosis is mainly based on the clinical findings. At present, no effective therapy is known.
Accidental Falls↗
Rat diaphragm contractility and histopathology are affected differently by low dose treatment with methylprednisolone and deflazacort.
The extent to which treatment with low doses of the nonfluorinated steroid methylprednisolone affects diaphragm contractility and morphology is unknown. In the present study, we compared the effects of equipotent doses of methylprednisolone and deflazacort, an oxazoline derivate of prednisolone with less systemic side-effects on bone structure and carbohydrate metabolism. Twenty six male adult rats were randomized to receive daily saline (control), methylprednisolone 0.4 mg.kg-1 or deflazacort 0.5 mg.kg-1 i.m. Contractile properties and histopathology were measured after a 6 week treatment period. During treatment, body weight increased in control and methylprednisolone-treated animals, but decreased by 4.2 +/- 1.1% (mean +/- SD) in the deflazacort group. Similarly, diaphragm mass in the deflazacort group was decreased compared to control and methylprednisolone groups. Twitch tension and twitch characteristics of isolated diaphragm bundles were similar in the three groups. Maximal tetanic tension was decreased in the deflazacort group. The force-frequency curve of the deflazacort bundles shifted downwards compared to control. Fatigue occurring during this protocol was greatest in the methylprednisolone- and deflazacort-treated animals. Microscopic examination revealed no gross abnormalities in the three groups. Histochemical analysis after staining for myosin adenosine triphosphatase (ATP-ase) showed that in the deflazacort group cross-sectional area of type I, IIa and IIb fibres were decreased. We conclude that low doses of methylprednisolone caused subtle and negligible changes in rat diaphragm contractile properties without affecting fibre dimensions, while deflazacort at an equipotent dose induced generalized fibre atrophy and changes in diaphragm contractility.
Animals↗
Neurocysticercosis: a poorly understood disease.
A 22-year-old male patient of Indian origin presented with generalized seizures. Brain magnetic resonance imaging (MRI) showed two cystic lesions. Extensive screening only revealed positive skin tests for tuberculosis. Immunoassays for cysticerosis were negative in serum and cerebrospinal fluid. Biopsy of the temporal lesion revealed a cysticercus. Although neurocysticercosis is a common cause of seizures in patients from countries where cysticercosis is endemic, the diagnosis can be difficult in a patient with evidence of multiple infections or in whom serological evidence is lacking, as is illustrated by the present case. Furthermore, because the pathogenic factors determining the activity of the disease are poorly understood, its management represents a similar problem as it depends upon the activity of the disease as estimated by clinical, radiological and laboratory tests. The present case report illustrates these difficulties.
Adult↗
Predictive testing for Huntington's disease: risk perception, reasons for testing and psychological profile of test applicants.
In the Center for Human Genetics in Leuven, predictive DNA-testing for Huntington's disease is available as a clinical service since November 1987, initially by DNA-linkage and since mid 1993 by direct mutation analysis. The multidisciplinary approach as well as the detailed test protocol are described. The present paper gives a sociodemographic description of the test applicants, their subjective evaluation of the risk and their motives for requesting the predictive test. Major attention is paid to the personality profile of the applicants who proceeded with testing. Psychometric testing revealed that this group of test applicants did not differ significantly from the general population for most characteristics and even had a number of more positive characteristics e.g. a higher ego-strength. The latter may reflect a self-selection of a more resourceful and emotionally healthier subgroup of at-risk persons. Nevertheless psychological evaluation also has identified a number of applicants with extremely high anxiety levels and other problems, who needed extra pretest and posttest counseling. The relatively high number of withdrawals from the test programme is another indication of the importance of adequate pretest counseling.
Adult↗
Appearance of localized immunoreactivity for the alpha 4 integrin subunit and for fibronectin in brains from Alzheimer's, Lewy body dementia patients and aged controls.
The localization of alpha 4 integrin subunit and of fibronectin in Alzheimer's disease (AD), Down's syndrome, Lewy body dementia (DLB) and normal brains was immunohistochemically investigated. Antibodies against the alpha 4 subunit and a fibronectin specific antibody stained 'neuritic' plaques in AD and Down's syndrome, while 'preamyloid' and 'burned-out' plaques remained negative. No alpha 4 integrin subunit or fibronectin immunoreactivity was detected in the plaques of DLB consistent with the absence of neuritic plaques. In addition, hippocampal pyramidal neurons and some neocortical neurons showed immunoreactivity with alpha 4 subunit and fibronectin antibodies in all aged individuals, but not in younger controls. These results suggest an age-related and localized expression of alpha 4 integrin subunit and fibronectin in the brain.
Adolescent↗
Deletion in the CMT1A locus on chromosome 17p11.2 in hereditary neuropathy with liability to pressure palsies.
Hereditary neuropathy with liability to pressure palsies (NHPP) is an autosomal dominant disease of peripheral nerves, characterized by recurrent focal neuropathies often with an underlying asymptomatic polyneuropathy. We report the clinical, electrophysiological, and histopathological findings in three families with HNPP and confirm the presence of a deletion on chromosome 17p11.2, including all the markers known to be duplicated in Charcot-Marie-Tooth disease type 1A. This deletion appears to be the underlying molecular deficit in this disease and provides additional evidence for the importance of this locus for peripheral nerve function.
Adolescent↗
Diagnosis of atypical intracerebral Langerhans cell histiocytosis suggested by concomitant lung abnormalities. A case report.
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Adult↗
Limited expansion of the (CAG)n repeat of the Huntington gene: a premutation (?).
Huntington's disease (HD) is an autosomal dominant disorder with choreic movements, psychiatric manifestations and cognitive dysfunction. Recently the IT15 gene on chromosome 4p has been identified containing an unstable and expanded trinucleotide repeat in patients with HD. We report on the characteristics of this repeat in 248 individuals from 41 Belgian HD families. The length of the expanded repeat was defined precisely and reproducibly on an ALF sequencer and correlated well with the age of onset (r = -0.72). Paternal transmission of the expanded repeat resulted on average in a significantly longer repeat length (+2.79 repeats) than maternal transmission (-0.29 repeats). (CAG)n repeat of a premutation (?) size was observed in this population with subsequent expansion in the disease range. Presymptomatic or prenatal testing using only linked markers may be problematic in these cases.
Adult↗
Tacrine in Alzheimer's disease.
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Alzheimer Disease↗
Towards an improved survival of rat brain neurons in culture by cerebrospinal fluid of patients with senile dementia of Alzheimer's type.
Neuronal cell survival was investigated in rat brain cortical cultures in the presence of increasing concentrations of human brain extracts or cerebrospinal fluid (CSF) from control and Senile Dementia of Alzheimer's type (SDAT) patients. Using hippocampal brain extracts, converted 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) was compared to the content of the neuronal marker MAP2 in foetal rat brain neuronal cultures in order to test converted MTT as a quantitative parameter for neuronal cell survival. A significant correlation was found between both parameters. SDAT frontal cortex brain extracts induced a two four-fold increase in neuronal cell survival at 25 to 125 micrograms protein extract, whereas control brain extracts induced at similar protein concentrations a decline in neuronal cell survival. The enhanced survival yielded by SDAT brain extracts was fully abolished in the presence of control brain extract. Control CSF concentration-dependently increased neuronal cell survival in postnatal rat brain neuronal cultures independent of the difference in the protein content of CSF samples and age of the patients. SDAT CSF also concentration-dependently enhanced neuronal cell survival, however, the effect was more pronounced compared to control CSF. These observations are in favour of the hypothesis that there might be a higher neurotrophic activity in SDAT brain tissue.
Adult↗