Inhibition of Induced Lymphocyte Proliferation by Lipid and Protein Components of the Syncytiotrophoblast Plasma Membrane

PROBLEM : The aim of this work was to define the respective responsibilities of the lipid and protein components of syncytiotrophoblast plasma membranes on the inhibition of lymphocyte proliferation induced in vitro. METHOD : A fractionation method using octyl-β-D-glucopyranoside enabled lipoprotein, lipid, and protein fractions to be isolated from the membrane. RESULTS: The lipid fraction was shown nonspecifically to inhibit lymphocyte proliferation, to a lower extent compared with the native membrane. Alternatively, the protein fraction used as a proteoliposome contained the totality of the cytostatic effect of the native fraction. CONCLUSION : These results are discussed generally in the context of the immunoregulatory role of membrane lipids and proteins and in relation to the local properties of syncytiotrophoblast plasma membrane components in fetal graft tolerance.     

Immediate effects of captopril in acute left ventricular failure secondary to myocardial infarction

Abstract. In eight patients with acute left ventricular failure secondary to myocardial infarction the haemo-dynamic effects of captopril (25 mg), an orally active converting enzyme inhibitor, were measured. Haemo-dynamic modifications were maximal at 60 min and lasted for 2–3 h. Pulmonary wedge pressure fell from 23–5± 4.9(mean ± SD)to 16–8 ± 4.7 mmHg(P<0–01), cardiac output rose from 3–24 ± 1 to 4–05 ± 0–91 1/min (P<001). Systemic vascular resistance decreased from 27–34 ± 3–81 to 17.52 ± 1–65 mmHg min 1^-1 (P<001). Mean arterial pressure fell from 89.6 ± 13.9 to 75.7±0 16.3 mmHg (P<0001) while heart rate was not significantly modified. Six patients who had high pretreatment plasma renin activity values responded by a decrease in ventricular filling pressure and/or an increase in cardiac output. One patient with normal initial plasma renin activity value showed similar haemodynamic effects. These data suggest that in the short term captopril is a vasodilator with both arterial and venous effects and improves cardiac function in acute left ventricular failure secondary to myocardial infarction.     

Percutaneous Mechanical Mitral Commissurotomy with the Metallic Valvulotome: Detailed Technical Aspects and Overview of the Results of the Multicenter Registry on 882 Patients

Percutaneous mechanical mitral commissurotomy (PMMC) is a new technique that has been developed over the last 3 years for the treatment of mitral stenosis. The device used opens the commissures by a direct action of two parallel bars located in a metallic head screwed at the distal end of a 13Fr catheter. Opening of the bars is obtained with the use of activating pliers attached at the proximal end of the catheter. The metallic dilator and the pliers can be safely reused after sterilization. The device and the direrent steps of the procedure are detailed in this article. The results of an international registry including 882 patients are reported here. PMMC could be achieved in 863 (98%) cases. Maximal opening of the bars was 40 mm in 90% of the cases. The technique resulted in an increase of the mitral valve area from 0.94 ± 0.2 cm² to 2.12 ± 0.4 cm². Bilateral splitting of the commissures was achieved in 85% of the cases. Complications occurred in 33 (3.7%) patients: pericardial tamponade in 1.4% (12 cases, one death), mitral regurgitation > grade 2 in 2.1% (18 cases, surgery required in 4), and transient stroke in 0.3% (3 patients). The role of the learning curve in the occurrence of complications has been clearly demonstrated. The cost of the procedure has been markedly decreased in developing countries due to multiple reuses of the device after sterilization.     

Algorithms for sleep–wake identification using actigraphy: a comparative study and new results

The aim of this study was to investigate two new scoring algorithms employing artificial neural networks and decision trees for distinguishing sleep and wake states in infants using actigraphy and to validate and compare the performance of the proposed algorithms with known actigraphy scoring algorithms. The study employed previously recorded longitudinal physiological infant data set from the Collaborative Home Infant Monitoring Evaluation (CHIME) study conducted between 1994 and 1998 [ http://dccwww.bumc.bu.edu/ChimeNisp/Main_Chime.asp ; Sleep 26 (1997) 553 ] at five clinical sites around the USA. The original CHIME data set contains recordings of 1079 infants <1 year old. In our study, we used the overnight polysomnography scored data and ankle actimeter (Alice 3) raw data for 354 infants from this data set. The participants were heterogeneous and grouped into four categories: healthy term, preterm, siblings of SIDS and infants with apparent life‐threatening events (apnea of infancy). The selection of the most discriminant actigraphy features was carried out using Fisher’s discriminant analysis. Approximately 80% of all the epochs were used to train the artificial neural network and decision tree models. The models were then validated on the remaining 20% of the epochs. The use of artificial neural networks and decision trees was able to capture potentially nonlinear classification characteristics, when compared to the previously reported linear combination methods and hence showed improved performance. The quality of sleep–wake scoring was further improved by including more wake epochs in the training phase and by employing rescoring rules to remove artifacts. The large size of the database (approximately 337 000 epochs for 354 patients) provided a solid basis for determining the efficacy of actigraphy in sleep scoring. The study also suggested that artificial neural networks and decision trees could be much more routinely utilized in the context of clinical sleep search.     

Trainee impact on advanced diagnostic bronchoscopy: An analysis of 607 consecutive procedures in an interventional pulmonary practice

Background and objective: Complications during advanced diagnostic bronchoscopy are rare and include: pneumothorax, bleeding, mediastinitis and lymphadenitis. Increased complications have been demonstrated in patients undergoing routine bronchoscopy procedures performed by trainees. This study aimed to determine the impact of trainees during advanced diagnostic bronchoscopy on procedure time, sedation use and complications. Methods: A retrospective review of a quality improvement database including consecutive pulmonary procedures performed by an interventional pulmonologist (D.R.S.) at the University of Calgary, from 1 July 2007 to 1 April 2011. Results: Six hundred seven (55.2%) of the 1100 procedures involved an advanced diagnostic procedure defined as: endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA), electromagnetic navigation bronchoscopy (ENB) and/or peripheral EBUS. A trainee participated in 512 (84.3%) procedures. A complication occurred in 25 patients (4.1%), with a trend towards increased complication rates in the trainee group (4.7% vs 1.1%, difference 3.6%, P = 0.076). Significant differences were seen when a trainee participated versus when no trainee participated for procedure length (58.32 min vs 37.69 min, difference 20.63 min (95% confidence interval: 19.07–22.19), P = 0.001) and for the dose of propofol (178.3 mg vs 137.1 mg, difference 41.2 mg (95% confidence interval: 19.81–63.38), P = 0.002). Conclusions: In an academic interventional pulmonology practice utilizing the apprenticeship model, trainee participation in advanced diagnostic bronchoscopy increased procedure time, increased the amount of sedation used and resulted in a trend to increased complications. Attempts to modify trainee procedural training to reduce the burden of procedural learning for patients are warranted.     

BCL6 gene rearrangements also occur in marginal zone B-cell lymphoma

Marginal zone B-cell lymphoma (MZBCL) represents a distinct subtype of B-cell non-Hodgkin's lymphoma (NHL) which has been recently recognized and defined as a disease entity. Cytogenetically, these lymphomas reveal a high prevalence of trisomy 3, and recent data obtained by comparative genomic hybridization indicate that the chromosomal regions 3q21-23 and 3q25-29 might be of particular pathogenetic significance. We identified structural chromosomal abnormalities involving the region 3q27 and rearrangements of the BCL6 proto-oncogene in three out of 34 (9%) well-defined cases of extranodal, nodal and splenic MZBCL using cytogenetic analysis, Southern blot, and fluorescence in situ hybridization (FISH). All three cases were characterized by a t(3;14)(q27;q32). Two of them showed additional chromosomal abnormalities including trisomy 3, which was found in one case. The patients displayed extranodal disease and did not demonstrate any striking clinical and histological differences when compared with MZBCL lacking BCL6 rearrangement. The present study for the first time demonstrates the occurrence of t(3;14)/ BCL6 gene rearrangement in MZBCL, thus suggesting a role of the BCL6 proto-oncogene in the pathogenesis of MZBCL.     

Perceptual context and the selective attention effect on auditory event-related brain potentials

Two experiments examined the effect of the perceptual context established through tonal grouping on neuroelectric responses during selective listening. Subjects monitored one of the extreme pitches in four-pitch tone sequences and detected rare longer tones of the designated pitch. In the first study, tonal grouping was manipulated by changing the tonal separation between the extreme pitches and their nearest neighbor, keeping the extreme pitches constant. Grouping increased the negativity of the attended–unattended difference potential. A second study examined the effect of grouping on the attention-related negativity when it opposed the effect of physical similarity. The proximity of extreme pitches varied, keeping the middle pitches constant. The effect of grouping on event-related potentials (ERPs) for the middle pitches was varied according to the tone being attended. ERPs for the middle tone adjacent to the attended tone became more negative with grouping, whereas ERPs for the distant middle tone became less negative with grouping. These effects suggest that the attention-related negativity is sensitive to contextual information.     

Platelet alpha2 adrenoceptors in Parkinson''s disease: decreased number in untreated patients and recovery after treatment

[3H]-yohimbine binding sites were quantified in platelets from Parkinsonians with no clinical signs of dysautonomia. Never-treated Parkinsonians had a lower specific binding than control subjects. This alteration was associated with decreased epinephrine-induced platelet aggregation. Treatment with dopaminergic agents induced a significant increment of [3H]-yohimbine binding sites. These results show that Parkinson's disease is associated with a reduced number of peripheral alpha 2 adrenoceptors and that dopaminergic agents induce partial recovery.     

DISCURSIVE STRATEGIES OF SUBJECTS WITH HIGH ALTITUDE HYPOXIA: EXTREME ENVIRONMENT

A discourse analysis was carried out on nine European lowlanders during a 2-month scientific expedition at high altitude including a 3-week stay in extreme survival conditions at the summit of Mt Sajama (6542 m), in order to contribute to the understanding of psychological adaptation to extreme environments. This discourse analysis was part of a wide-ranging scientific investigation involving 12 scientific and medical research protocols which targeted human adaptation to high altitude chronic hypoxia. The objective of this study is to better understand the presence of linguistic markers capable of translating the subject's psychological state when faced with a threatening environment. This study was based on a method of propositional speech analysis developed by Ghiglione and Blanchet which emphasizes the cognitive function of verb categories, modalizers and adjuncts used by subjects. The method was developed in conjunction with psychopathological studies of the depressive state. Speech was recorded at time T 1, 4 days after reaching the summit of Mt Sajama, and at time T 2, 2 days before descending the mountain peak. These results revealed that in the absence of depression in any psychopathological sense of the word, normal subjects would react to their environment with a depressive component. However, the results of this study equally illustrate for some subjects a correspondence between those states with a depressive component and a physiological incomplete adaptation to high altitude. This correspondence could reflect the pathogenic effect of an adaptation deficit or could be in keeping with the literature concerning an incomplete adaptation effect induced by a latent depressive state.©1997 John Wiley & Sons,Ltd.