Visual and visuospatial short-term memory in mild cognitive impairment and Alzheimer disease: role of attention.

It has been proposed that visual recognition memory and certain attentional mechanisms are impaired early in Alzheimer disease (AD). Little is known about visuospatial recognition memory in AD. The crucial role of the hippocampus on spatial memory and its damage in AD suggest that visuospatial recognition memory may also be impaired early. The aim of the present study was to evaluate which modality, i.e. visual or visuospatial, is more implicated in the early memory impairment in AD. First, to determine onset of memory impairment, we compared the performances of patients with AD to those with amnestic mild cognitive impairment (MCI). Second, to determine the relative contribution of attentional impairment on the performance of MCI and AD patients, we tested the influence of a distractor in the interval between the memory image and recognition tests. Results showed that visuospatial short-term deficits appear earlier than visual short-term ones. In addition to mnemonic deficits, results showed attentional deficiency in both MCI and AD patients. Deficits of performances in visual modality seemed of attentional origin whereas those of visuospatial modality seemed of memory origin. The combination of attentional and mnemonic evaluation is likely to be a promising approach to finding predictive markers that distinguish MCI patients that convert to AD.

Correlation between active E-rosettes and antigens defined on peripheral lymphocytes by OKT 4 and OKT 8 monoclonal antibodies.

A relationship has been sought between the classical marker, active E-rosette and the surface antigens of T-lymphocytes, defined by OKT 4 and 8 monoclonal antigens, in the peripheral blood of normal human people. It was found that no significant correlation existed in the case of OKT 4 antigen; conversely the OKT 8-positive cells were significantly enriched after E-rosette-forming cell isolation (about 2.5 times in comparison with the negatively selected cells). In this latter case, some partial correlation could exist between SRBC-high affinity of T-lymphocytes and the subsets defined by OKT 8 antigen.

Pharmacokinetics of cyclophosphamide administered alone or in combination with vindesin or cisplatin in 5 patients with bronchial adenocarcinoma.

The pharmacokinetics of cyclophosphamide (CPH) administered intravenously at doses between 200-400 mg alone or in combination with vindesin (VDS) or cisplatin (cisPt) were studied in 5 patients who had bronchial adenocarcinoma, with normal liver and kidney functions. The linearity and the reproducibility of CPH kinetics were confirmed and its pharmacokinetic parameters were found to be unaffected by simultaneous or sequential administration of either vindesin or cisplatin. Total clearance was 7.69 +/- 3.53 1.hr-1 for CPH administered alone and 6.76 +/- 1.63 1.hr-1 for CPH administered with vindesin. Biological half-life was 4.3 +/- 1.5 hr (CPH alone) and 5.1 +/- 2.2 hr (CPH + VDS).

[Treatment of bullous pemphigoid by plasma exchange and prednisolone]. / Traitement de la pemphigoïde bulleuse par échanges plasmatiques et prednisolone.

Between March, 1983 and March 1984, 12 previously untreated patients (7 men, 5 women) with biopsy proven active bullous pemphigoid entered this open study. Their initial therapy associated oral prednisolone 0.5 mg/kg in divided daily doses with 4 large volume plasma exchanges (one and half the theoretical plasma volume) over 2 weeks. The disease was considered under control when new blisters and pruritus were absent for 2 consecutive weeks. This initial treatment was well tolerated by these elderly patients (mean age 80 +/- 9 years), with no death and no major complication. Eight patients were controlled within 29 +/- 4 days. During progressive decrease of steroid dosage 5 of these 8 patients remained well (mean follow-up 7 months), 2 relapsed and one died of marasmus. Among the 4 patients who were not controlled, 3 needed only a slight increase in prednisolone doses (0.75 mg/kg/d) and 1 required up to 1 mg/kg/d and 4 additional plasma exchanges. This study suggests that a combined treatment with moderate doses of prednisolone and 4 large volume plasma exchanges is well tolerated and highly effective in bullous pemphigoid.

An Adaptive Resonance Theory account of the implicit learning of orthographic word forms.

An Adaptive Resonance Theory (ART) network was trained to identify unique orthographic word forms. Each word input to the model was represented as an unordered set of ordered letter pairs (open bigrams) that implement a flexible prelexical orthographic code. The network learned to map this prelexical orthographic code onto unique word representations (orthographic word forms). The network was trained on a realistic corpus of reading textbooks used in French primary schools. The amount of training was strictly identical to children's exposure to reading material from grade 1 to grade 5. Network performance was examined at each grade level. Adjustment of the learning and vigilance parameters of the network allowed us to reproduce the developmental growth of word identification performance seen in children. The network exhibited a word frequency effect and was found to be sensitive to the order of presentation of word inputs, particularly with low frequency words. These words were better learned with a randomized presentation order compared with the order of presentation in the school books. These results open up interesting perspectives for the application of ART networks in the study of the dynamics of learning to read.

Assessment of metastable atom bombardment (MAB) ionization mass spectrometry for the fast determination of heterocyclic aromatic amines in cooked meat.

An investigation of metastable atom bombardment (MAB) ionization mass spectrometry for the fast characterization of mutagenic/carcinogenic heterocyclic aromatic amines (HAAs) formed during heating processes of meats is presented. The aim of our study was to use the selective ionization of MAB to develop a detection method for HAAs in non-purified meat extracts, thus avoiding purification and concentration steps and reducing analysis time. Sample introduction into the MAB ion source was achieved by pyrolysis, allowing the direct and fast insertion of complex food extracts into the mass spectrometer. Analysis conditions were optimized on standard HAAs by using different ionization gases for the MAB process. Metastable nitrogen was selected as the best MAB gas for the analysis of HAAs. Ionization selectivity is shown by the detection of heterocyclic amines in non-purified chicken meat extracts spiked with HAAs. A quantitative approach is also presented by using pyrograms as chromatograms for quantification purposes. HAAs determination using Py-MAB-ToF was finally performed on cooked chicken breast extracts and compared to an LC-APCI-MS/MS method. Although Py-MAB-ToF sensitivity remains to be improved in the present state of development of our prototype device, only 2 h from the cooking were required to obtain quantitative results in good agreement with HAAs concentrations measured by LC-MS/MS in 36 h. Figure Experimental set-up for pyrolysis-MAB-ToF mass spectrometry experiments.

[Sialography of the submaxillary glands. A technique for catheterization of Wharton's duct (author's transl)]. / Sialographie des glandes sous maxillaires. A propos d'une technique de cathétérisme du canal de Wharton.

Except in cases where stones are present, it is often difficult to catheterize Wharton's duct through the opening when conducting sialography of the submaxillary glands. When direct catheterization is impossible the authors perform indirect catheterization proximal to the opening by turning back a periorificial mucous flap, posteriorly concave, after exposing the canal.

[Bypass whartonostomy (author's transl)]. / Whartonostomie de dérivation. Indications, technique, résultats.

Submaxillary salivary retention, associated with the typical sign of a painful swelling, is usually but not specifically due to the presence of stones. Other factors may indeed be involved (reflex secretory dysfunction, stenosis from a scar, inflammation or tumor of wharton's duct). The authors describe a technique, employed in 14 patients, which involves a permanent bypass of "salivary flow" by the creation of a new excretory orifice in wharton's duct proximal to the obstacle producing salivary stasis. This technique is used as a complement to treatment of the cause of salivary retention, and appears to improve long-term results especially in some types of disorders due to submaxillary stones.

[The stomatological complications of Steinert's disease. Apropos of a case]. / Incidences stomatologiques de la maladie de Steinert. A propos d'une observation.

Steinert's disease is a myotonic dystrophy associated with diffuse visceral involvement. A severe hereditary disorder, it is characterised from a maxillo-facial standpoint by a special dysmorphism which the authors emphasize in the light of one case. They then suggest that a wider study of this condition might be envisaged.

How many plasma exchanges to cure thrombotic thrombocytopenic purpura?

7 patients were treated by plasma exchanges and antiplatelet drugs for thrombotic thrombocytopenic purpura (TTP). The effectiveness of therapy was reviewed daily and retrospectively estimated on day 3, d6, d9, and d12. 6 of these 7 patients were cured. The low predictive value of the initial response to therapy is underlined. The clinical and biological status on d12 seems to have the best predictive value for the final outcome. These data encourage us to continue the plasma exchanges until d12, whatever the initial response to therapy in TTP.

[In vitro cloning of human tumor stem cells]. / Clonage in vitro de cellules souches tumorales humaines.

This study summarizes a one-year work experience in the area of human tumor stem cells cloning techniques. We found that it was more advisable to use an enzymatic method for dissociating solid tumors. The breast tumors possessing an unfavourable histoprognostic grade were found to grow up more easily in culture, which is a confirmation of known relationships between cell differentiation degree and cell proliferation. The high frequency of failures in the obtention of colonies did not allow to use this technique in daily clinical practice to study the in vitro sensitivity to drugs of a definite tumor. An improvement in the conditions of culture and the comparison with other in vitro methods for the prediction of response to oncostatics--particularly the incorporation of radioactive precursors (Livingston and coll., 1980)--will be attempted in future work.

Evidence of 3 beta-hydroxysteroid dehydrogenase activity in several murine embryonal carcinoma cell lines.

This report describes, for the first time to our knowledge, a possible steroidogenic activity in established murine embryonal carcinoma cell lines (PCC3, PCC4, F9), revealed by a 3 beta-hydroxysteroid dehydrogenase activity (revelation of NADH2 by staining, and RIA assessment of delta 4-androstenedione). The remarkable analogy between such totipotent cells and embryonal cells may suggest that this activity could be present before histologic organization of the embryonal testis. Nonmalignant embryonal cells such as fibroblasts (3/A/1/D-3) or myoblasts (T984) were also found to possess a 3 beta-hydroxysteroid dehydrogenase activity, thus suggesting that this enzyme is not specific to hormone-secreting cells, but the sign of a more general phenomenon.