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Biomedical subjects

L Cartier

Publications and source records attributed to L Cartier.

At least 73 records · Page 4Linked to original sources
PubMed1991

Creutzfeldt-Jacob disease associated with the PRNP codon 200Lys mutation: an analysis of 45 families.

200Lys mutation in the human PRNP coding region has been identified in 45 of the 55 CJD-affected families thus far presented to our NIH laboratory. These codon 200Lys families have a total of 87 patients, and originate from 7 different countries: Slovakia, Poland, Germany, Tunisia, Greece, Libya, and Chile. Forty-seven patients were neuropathologically verified, and brain tissue from 14 patients transmitted disease to experimental primates. The mutation was found by direct sequencing in 4 patients, and it was detected by restriction endonuclease analysis with BsmA 1 and/or the single nucleotide extension reaction in 36 other patients and 45 of 109 first degree relatives (1 parent, 14 siblings, and 30 children). The mutation is associated with all known geographical clusters of CJD (Slovakia, Libyan Jews, Chile) in which the annual mortality rate is tens or hundreds of times higher than the world average of 1 per million. All patients originating from the cluster areas carried the mutation, but it was seen in only 1 of 103 unrelated control individuals from the same areas, and in none of 102 controls from other areas, indicating a strong association between the mutation and disease. The penetrance of the mutation was estimated to be 0.56. Branches of some families migrating from cluster areas to other countries continue to have CJD over several generations, suggesting that CJD in these families is a genetic disorder, in which the 200Lys mutation is responsible for the disease.

Africa↗
PubMed1991

Evoked potential abnormalities in progressive spastic paraparesis associated to HTLV-1.

The electrophysiological features of progressive spastic paraparesis (PSP) associated with HTLV-1 in Chile, a non-tropical country, are presented. Twenty-two of 45 PSP subjects were positive for HTLV-1 antibodies. Trimodal evoked potentials were all normal in only 2 of these cases (9.1%). Somatosensory evoked potentials (SSEPs) were abnormal in 19 patients (86.3%) with a mean amplitude of 1.31 uV SD 0.92. Visual evoked potentials (VEPs) and brainstem auditory evoked potentials (BAEPs) were normal in all patients except four. Peripheral nerve conduction was normal in all but one who showed discrete slowness of the motor conduction velocity in the peroneal nerves. EMG was normal in 15 cases in whom it was performed. SSEP's were abnormal in 2 (8.7%) of 23 HTLV-1 negative cases with a mean amplitude of 2.4 uV SD 1.5, which is statistically different with respect to the positive cases (p less than 0.001). These results support an involvement of the spinal cord not restricted to the pyramidal tracts but also including subclinical damage of the posterior columns in PSP associated to HTLV-1.

Adult↗
PubMed1991

Simultaneous adult T-cell leukemia/lymphoma and sub-acute polyneuropathy in a patient from Chile.

This paper reports a case of adult T-cell leukemia/lymphoma associated with human T-cell lymphotropic virus type I (HTLV-I) diagnosed in a Chilean patient who developed after 1 1/2 years a crisis with a progressive sensorimotor polyneuropathy. Serum and cerebrospinal fluid HTLV-I antibody tests were positive and HTLV-I DNA was clonally integrated in peripheral lymphocytes. This case is unusual in having simultaneous neurological disease. Along with other recent data from South America, this suggests that the endemic area of HTLV-I may spread far beyond the Caribbean area.

Adult↗
PubMed1990

[HTLV-I retrovirus in Chile: study on 140 neurological patients].

We screened 140 patients with different neurological diseases for the presence of anti HTLV-1 virus antibodies. ELISA test confirmed with Western Blot analysis was performed in CSF and blood. Positive findings were obtained in 23 out of 52 patients with progressive spastic paraparesis (44%). All patients with multiple sclerosis, polymyositis, amyotrophic lateral sclerosis or chronic polyneuropathy were negative. Patients with progressive spastic paraparesis and positive HTLV-1 antibodies were most commonly women (78%) and middle aged (mean 46 years old), with a history of surgical interventions (70%) or blood transfusion (35%). A slowly progressive spastic paraparesis with asymmetric onset and minimal sensory complaints was observed in some cases. Mononuclear pleocytosis in the CSF was observed in 35% with an increased IgG index in 88%. A delayed latency and low amplitude of somatosensory evoked potentials was observed in 89% of patients.

Adolescent↗
PubMed1989

The nucleus basalis of Meynert in 20 definite cases of Creutzfeldt-Jakob disease.

The population of neurons and the neuronal size in the nucleus basalis of Meynert (nbM) were studied in 20 patients with definite Creutzfeldt-Jakob disease (CJD). When compared with a normal control group, the 20 CJD brains showed a significant loss of neurons and reduction of neuronal size, mainly in the middle level of the nbM and mostly affecting the right side. Since these findings show some parallelism with the amount of cortical damage and given the scarce gliosis and spongiosis found in only six of the 20 CJD brains, we postulate that the involvement of the nbM in CJD is a retrograde abnormality secondary to the damage of the neocortex.

Adult↗
PubMed1987

Neuropathological changes in the rat brain cortex in vitro: effects of kainic acid and of ion substitutions.

The ionic mechanisms that may contribute to the neurotoxicity of kainic acid, were studied in a system of rat thin neocortical slices superfused in vitro. Slices superfused for 3 h under control conditions showed an essentially normal aspect when studied by light microscopy. Presence of 30 microM kainate in the superfusion fluid induced neuronal swelling, nuclear condensation and signs of necrosis in some cells, while other neurons, especially in deeper layers, appeared dark and condensed, with microvacuolation. The neuropil presented numerous profiles of swollen dendrites. When the slices were superfused with chloride-free medium, a large number of pyknotic neurons was seen. This was further enhanced by 30 microM kainate, which produced no swelling in this medium. These effects of Cl-free medium were almost entirely prevented in Cl-free medium without calcium and with 0.1 mM of EGTA. Sodium-free medium induced a marked neuronal swelling that was not much changed by kainate. When calcium in an otherwise normal superfusion fluid was reduced to 0.1 mM, a large number of pyknotic neurons, some with incrustations, were seen. Kainate (30 microM) in this low calcium medium led to a very large swelling and destruction of neurons, and to a spongy neuropil. These effects of kainate were greatly intensified in calcium-free-EGTA (0.1 mM) medium. Ca-free-EGTA medium by itself induced considerable neuronal and neuropil swelling. It is concluded that kainate induces neuronal swelling by a sodium- and chloride-dependent mechanism, and the enhancement of swelling in low calcium is due to an increased sodium uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Chorionic villi sampling: women's attitudes.

To determine the acceptability of chorionic villi sampling (CVS) to women eligible for prenatal diagnosis, we undertook a survey to identify aspects of this new procedure that made it more or less preferable than amniocentesis. All women greater than or equal to 35 years scheduled for amniocentesis were asked to read some detailed descriptive material about amniocentesis and CVS, to rate the importance of the specific differences between procedures, and to indicate which procedure they would prefer, first considering each difference between them independently and then considering all the factors jointly. In the absence of precise estimates of CVS-associated risk at the time of the survey, almost equal proportions preferred amniocentesis and CVS (50.2 and 45.1%, respectively). Risk information was the most important factor to women preferring amniocentesis; the timing of the test or nature of the termination procedure was most important to those preferring CVS. In the hypothetical case where CVS was stipulated to have the same attributable risk as amniocentesis, 82% of respondents would prefer it. However, if the spontaneous abortion rate following CVS was stipulated to be 5% more than the amniocentesis risk, preferences reversed and only 22% would still prefer it. Thus, the data suggest that the ultimate acceptability of the new procedure for women over 35 years seeking prenatal diagnosis will depend on the risk associated with it and underscore the importance of ongoing trials aimed at establishing this risk.

Abortion, Induced↗
PubMed1985

Familial clustering of the ataxic form of Creutzfeldt-Jakob disease with Hirano bodies.

A family cluster of the ataxic form of Creutzfeldt-Jakob disease with one probable and two autopsy proven cases that occurred in a single generation between 1974 and 1982 is reported. The clinical characteristics of the cases are closely similar to those of kuru patients, with a fair correlation between the prominent truncal ataxia and the intense devastation of the cerebellar cortex most marked in the vermis. Pathologically, the marked hippocampal involvement rarely seen in typical transmissible Creutzfeldt-Jakob disease and the finding of Hirano bodies in the Ammon's horn without specific Alzheimer's senile changes are noteworthy features.

Caudate Nucleus↗
PubMed1984

A private view of heterozygosity: eight-year follow-up study on carriers of the Tay-Sachs gene detected by high school screening in Montreal.

We surveyed 264 persons (132 carriers, 132 matched noncarriers) screened for Tay-Sachs heterozygosity during 1974-76 in a program directed at senior high school students in Montreal. Among 198 who apparently received the questionnaire in 1982, the response rate was 42% (38 carriers, 45 noncarriers; age range 21-26 yr). Respondents and nonrespondents had no apparent demographic differences. Of eight unable to remember their genotype only one was a carrier (these persons were excluded from the study). The subjects were: single (75%), married (20%), engaged (3%), divorced (1%); 32% of carriers were engaged or married vs 16% of noncarriers. (There were no carrier couples in our sample, but one such couple, who married after being screened in the high school program, requested amniocentesis in 1981.) Only three of the 12 spouses or fiancé(s) of carriers have not been tested (vs 3 of 6 noncarrier partners). Only 19% of carriers now attach any "worry" to heterozygosity (vs 46% at the earlier time of test disclosure, P = 0.001); carriers with spouses or fiancé(e)s are less "worried" than unattached carriers. Only 3% of carriers claim they would change marriage plans if their fiancé(e) was also a carrier. Carriers and noncarriers uniformly approve (96%) genetic screening for themselves and for other mutant genotypes; 92% of carriers and 95% of noncarriers approve being screened in high school. These findings indicate that Canadians screened in high school: 1) have largely positive attitudes toward genetic screening long after the experience, and 2) are making appropriate use of the test result.

Adult↗
PubMed1984

Computed tomography findings in 15 cases of Creutzfeldt-Jakob disease with histological verification.

Computed tomography (CT) was normal in twelve of fifteen patients with definite Creutzfeldt-Jakob disease. In two patients CT showed mild sulcal widening, while marked ventricular enlargement and moderate cortical atrophy were seen in a patient who had both Creutzfeldt-Jakob disease and normal pressure hydrocephalus. No correspondence was observed between CT findings, severity of the clinical picture and postmorten gross brain examination. According to these results, a normal CT in a demented patient should suggest Creutzfeldt-Jakob disease. Conversely, CT is of value for the diagnosis of other potentially reversible illnesses clinically resembling Creutzfeldt-Jakob disease.

Adult↗
PubMed1984

Beta-thalassemia disease prevention: genetic medicine applied.

We report here an evaluation of a program for thalassemia-disease prevention, comprising education, population screening for heterozygotes, and reproductive counseling; the evaluation includes cost analysis. A preprogram survey in 1978 of 3,247 citizens in the high-risk communities (85% were high-school students) showed that 88% favored a program but that only 31% considered fetal diagnosis as an acceptable option. Screening in high school or before marriage was preferred by 56%. In a 25-month period (December 1979-December 1982), we screened 6,748 persons, including 5,117 senior high-school students, using MCV/HbA2 indices. The participation rate was 80% in the high-school group. The frequency for beta-thalassemia heterozygosity was 4.7% with 10-fold variation among ethnic groups at risk; the overall frequency for all variants found was 5.4%. We surveyed 60 carriers and 120 noncarriers after screening high-school students (response rate 77%): most carriers told parents (95%) and friends (67%) the test result; and 38% of the carriers' parents (vs. 18% of the noncarriers' parents) were also screened. Carriers would ascertain their spouses' genotype (91%) and approved uniformly (95%) the high-school screening experience and its goal. We performed 11 fetal diagnoses in a 25-month interval (greater than 75% participation in target population) either by fetoscopy and globin-chain analysis or by amniocentesis and genomic DNA analysis; two of three affected fetuses were aborted at parental request, there was one spontaneous abortion (after fetoscopy), and seven live births. The at-risk couples claimed pregnancy would not be contemplated without the fetal-diagnosis option. We analyzed economic costs of the program: cost per case prevented is approximately equal to $ 6,700, slightly less than cost-per-patient-treatment-year or about 4% of undiscounted treatment cost incurred in the first 25 years of life for an affected individual. These findings indicate: collective acceptance of the program, appropriate attitudes among carriers, general acceptance and efficacy of fetal diagnosis, and global cost-effectiveness.

Adolescent↗
PubMed1983

Familial Creutzfeldt-Jakob disease in Chile.

Of the 87 cases of Creutzfeldt-Jakob disease (CJD) ascertained in Chile since 1931, 39 are familial accounting for 45% of all cases, and 25% of the 51 definite cases. There are 11 affected families with an average of 3.5 affected members per family, and a rate of occurrence consistent with autosomal dominant transmission. There is no evidence for maternal lineage, and age at death is not significantly different from that of sporadic cases. About half of the cases died around the same age, suggesting some form of vertical transmission. Three pairs of affected members in 3 different families died at the same time, possibly indicating common exposure to CJD agent. The study of absolute death intervals and temporal and spatial separations between affected members suggests minimum incubation periods ranging from 2 to 37 years, assuming case-to-case transmission. CJD occurring in a woman related by marriage to one of the affected families strongly argues for horizontal transmission. The high proportion of familial CJD observed in Chile is probably the result of both a genetically determined susceptibility to the CJD virus, and a high degree of case ascertainment. However, the present study leaves unanswered the mode of transmission of the agent within the affected families.

Adult↗
PubMed1982

[Syndromic diversities in Creutzfeldt-Jakob disease: neurophysiological and histopathological correlates].

Two syndromatic forms of Creutzfeldt-Jakob disease are illustrated with data from two cases confirmed by necropsy and studied by means of electroencephalogram, evoked potential recording and neuropathological techniques. One of the cases presented the typical hypersynchronous periodic discharges through to be characteristic of this disease. The other did not exhibit epileptiform discharges, showing an evolution in which progressive diffuse slowing was the prominent feature. Cortical spongyosis, gliosis, and neuronal lose were intense in the case showing spikes, and moderate in the one without spikes. Subcortical involvement was similar in both cases. This different topography of pathological involvement might explain, in addition to electroencephalographic findings, the different behavior of somatosensory evoked potentials, which were of larger amplitude in the case showing epileptiform discharges, although in both cases deterioration of clinical state was accompanied by a progressive amplitude decrement in the evoked potential. Sleep induced by barbiturates was disrupted in the case with spikes, its pattern being closer to normal in the case with less severe cortical involvement. A Wada test demonstrated that discharges in the hemispheres were independent. Spike periodicity is discussed. It is postulated that the heavier involvement of cortical layers II to IV deprive the remaining pyramidal cells of inhibitory influences, a condition which might explain the generation of periodic spike discharges.

Adult↗