Suicide attempts and job insecurity: a complex association

Objective:

Since Durkheim, epidemiological studies have revealed a significant, complex association between unemployment and suicidal behaviour. The aim of this study was to analyse the relationship between parasuicide and job instability, including unemployment, French social measures against unemployment and occasional work.

Method:

Demographic data, personal and familial characteristics were collected in 541 suicide attempters.

Results:

Seventy-seven per cent were socially active, with 61.5% in regular employment, and 38.5% in precarious employment. The female-to-male ratio approached 2 in the securely employed sample, and fell to 1 for those with poor social and professional integration. Depression, parasuicide, and alcohol abuse were more common in the families of repeaters in secure employment. The impact of the familial psychiatric background was no longer significant in the job insecurity group. Fostering in childhood was a risk factor for repeat suicidal behaviour in the group with job insecurity.

Predictive value for paravalvular regurgitation of 3-dimensional anatomic aortic annulus shape assessed by multidetector computed tomography post-transcatheter aortic valve replacement

AIMS

Paravalvular regurgitation (PAR) remains a serious complication after trans-catheter aortic valve replacement (TAVR). Multidetector computed tomography (MDCT)-based measurements of the aortic basal virtual ring (BVR) are considered the gold standard for trans-catheter heart valve (THV) sizing. However, the real anatomic aortic annulus is a 3-dimensional structure. To compare measurement of 3D-anatomic annulus with BVR and secondly to assess independent predictive parameters that may impact on PAR > mild post-TAVR (PAR+).

METHODS AND RESULTS

MDCT was performed in 92 patients before and after balloon or self-expandable TAVR. 3D-AA shape was obtained point by point following the semilunar attachment of aortic cusps (Osirix-MD 2.8.2). 3D-oversizing index (nominal THV area/3D-AA area - 1) × 100 was calculated as well as 2D-oversizing index using BVR area instead of 3D-AA area. PAR was quantified by planimetry of vena-contracta in transthoracic echocardiography short-axis view. Valvular calcium volume and annulus calcium area were measured using Hounsfield-intensity detection. ROC curves and logistic regression for PAR(+) were performed. BVR area overall underestimated 3D-AA area by 19 ± 9% (P< 0.001), significantly more in PAR(+) (26 ± 7%) vs. PAR(-) (17 ± 9%, P< 0.001). 3D-oversizing index had greater predictive value for PAR > mild (area under the curve, AUC = 0.88) with 88% sensibility (Se) and 82% specificity (Sp) than 2D-oversizing index (AUC = 0.68) with 84% Se, but only 41% Sp (P< 0.0001). Also, valvular calcium volume and annulus calcium area were less predictors for PAR > mild (AUC = 0.68, respectively, AUC = 0.75, P = 0.002). In a multivariate analysis, only 3D-oversizing index showed an independent value for PAR > mild (OR = 18.6, P< 0.001).

CONCLUSION

Basal ring CT measurement significantly underestimated the real 3D-anatomic aortic annulus area. This may impact on THV sizing and PAR incidence. 3D-oversizing index is the most predictive factor for PAR > mild.

Unipolar Signal Modification as a Guide for Lesion Creation During Radiofrequency Application in the Left Atrium

Background—

In patients treated for paroxysmal atrial fibrillation, the pulmonary vein (PV) reconnection rate is substantial and may be related to the lack of transmurality achievement while performing PV isolation (PVI). It has been experimentally demonstrated that positive unipolar atrial electrogram completion, when applying radiofrequency energy, was associated with transmural lesions. In this regard, we seek to determine whether the unipolar signal modification may be an appropriate end point for point-by-point radiofrequency application and find out whether it could improve the paroxysmal atrial fibrillation ablation results in humans.

Methods and Results—

Fifty consecutive patients (61±8 years old, 41 men) with paroxysmal atrial fibrillation underwent PVI using Carto and Lasso. Each radiofrequency application lasted until development of a completely positive unipolar electrogram. Fifty patients (63±9 years old, 40 men), who previously underwent PVI following the standard approach of our institution, corresponded to the control group. All PVs were isolated in all patients of both groups. However, the procedural and ablation times were significantly lower in the unipolar group compared with those of the control group, whereas the PV reconnection rate, after 30 minutes of waiting time, was not significantly different. Overall, 21±4 months after 1 PVI session, the sinus rhythm maintenance rate without antiarrhythmic drugs was significantly higher ( P =0.027) in the unipolar group (88%) compared with that of the control group (70%).

Conclusions—

Unipolar signal modification is a useful end point for radiofrequency energy delivery in patients with paroxysmal atrial fibrillation who undergo PVI and leads to a substantial midterm sinus rhythm maintenance rate.

Impact of body mass index on the one-year clinical outcome of patients undergoing multivessel revascularization with sirolimus-eluting stents (from the Arterial Revascularization Therapies Study Part II)

The differential safety and efficacy profiles of sirolimus-eluting stents when implanted in patients with multivessel coronary artery disease who have increased body mass indexes (BMIs) compared with those with normal BMIs are largely unknown. This study evaluated the impact of BMI on 1-year outcomes in patients with multivessel coronary artery disease treated with sirolimus-eluting stents as part of the Arterial Revascularization Therapies Study Part II (ARTS II). From February to November 2003, 607 patients were included at 45 centers; 176 patients had normal BMIs (<25 kg/m(2)), 289 were overweight (> or =25 and < or =30 kg/m(2)), and 142 were obese (>30 kg/m(2)). At 30 days, the cumulative incidence of the primary combined end point of death, myocardial infarction, cerebrovascular accident, and repeat revascularization (major adverse cardiac and cerebrovascular events) was 3.4% in the group with normal BMIs, 3.1% in overweight patients, and 2.8% in obese patients (p = 0.76). At 1 year, the cumulative incidence of major adverse cardiac and cerebrovascular events was 10.8%, 11.8%, and 7.0% in the normal BMI, overweight, and obese groups, respectively (p = 0.31). In conclusion, BMI had no impact on 1-year clinical outcomes in patients with multivessel coronary artery disease treated with sirolimus-eluting stents in ARTS II.

Premorbid IQ estimates from a multiple aptitude test battery: regression vs. equating

Estimation of premorbid abilities remains an integral part of neuropsychological evaluations. Several methods of indirect estimation have been suggested in the literature. Many of these methods are based in prediction via linear regression. Unfortunately, linear regression has the well-reported tendency to underpredict high IQ scores and overpredict low IQ scores. This can be shown to be an unavoidable statistical artifact of linear regression. We demonstrate a procedure to estimate premorbid IQ without the regression artifact. The procedure has two steps: confirmation of construct equivalence and psychometric equating. An example using real data is presented which shows the regression to the mean problem with prediction and compares it to the results from equating.

TP-10 (AVANT Immunotherapeutics)

AVANT Immunotherapeutics is developing TP-10, a recombinant soluble complement receptor type 1 (sCR1), for the potential treatment of reperfusion injury (following surgery, ischemic disease and organ transplantation), organ rejection, acute inflammatory injury to the lungs and autoimmune diseases [348669]. TP-10 has been awarded Orphan Drug status from the FDA for the prevention and reduction of adult respiratory distress syndrome (ARDS) and as a treatment for infants undergoing cardiac surgery [180849], [359588]. A placebo-controlled phase II trial, conducted at approximately 30 sites in the US and involving approximately 600 adult patients undergoing cardiac surgery utilizing cardiopulmonary bypass, was initiated in November 2000. This safety and efficacy study was designed to assess the ability of TP-10 to mitigate the injury to the heart, brain and other organs that occurs when patients are placed on cardiopulmonary bypass circuits, thus potentially improving postoperative outcomes [391437]. In September 2000, the company was planning a double-blind, placebo controlled phase IIb trial in infants undergoing cardiac surgery; AVANT expected to initiated in 30 infants in January 2001 [395086]. The data from this trial will enable the company to further define its clinical endpoints before inititating a pivotal phase III trial in 2001 [382529]. A phase I/II trial of TP-10 involving 15 infants, under 12 months of age, undergoing cardiac surgery for congenital heart defects was initiated by the company in September 1999. The trial will evaluate the ability of TP-10 to mitigate the injury to the heart and other organs when patients are placed on cardiopulmonary bypass circuits [340602]. Enrollment was complete by January 2000 [352458]. Phase I safety trials of TP-10, including studies in adult patients at risk for adult respiratory distress syndrome (ARDS), adult patients with first-time myocardial infarction (heart attack), and pediatric patients undergoing cardiac surgery demonstrated that TP-10 is well tolerated. However, after completion, in December 1997, of a phase IIa trial in nine patients with ARDS, AVANT decided to cease development for this indication. TP-10 was licensed to Novartis AG for use in xeno- and allotransplantation in July 1999. Extensive animal studies have shown TP-10 to have potential in a wide variety of complement-mediated conditions, including organ transplantation, multiple sclerosis, rheumatoid arthritis and lupus [238093]. Early work demonstrated favorable results in animal models of reperfusion injury [180849] and hyperacute xenograft rejection in guinea pig to rat and pig to primate organ transplants [191552]. AVANT has received Notices of Allowance (July 1998) from the USPTO for three separate patent applications covering pharmaceutical compositions of TP-10, methods of purification and methods of certain TP-10 glycoforms for treating diseases or disorders resulting from inappropriate complement activation [291776]. In January 1999, the company was awarded US-05856297 which covers pharmaceutical compositions of TP-10. US-05856300 was also awarded covering compositions and methods of producing the drug [312267].

Use of brook char (Salvelinus fontinalis) physiological responses to stress as a teaching exercise

Fish hematological changes during osmotic and cold stress are used to introduce the physiological reactions of the animal to an acute stress. Brook char (Salvelinus fontinalis) were subjected to 1 h of stress before being anesthetized and having blood taken from their caudal vein. Glucose, hemoglobin, hematocrit, and osmolarity were determined in the blood samples. Analyses showed that glucose concentration tends to increase and hematocrit tends to decrease in stressed fish. Changes in hemoglobin concentration occurred only in cold-stressed fish. A rise in blood glucose concentration is the result of cortisol secreted by the hypothalamic-pituitary-adrenal axis. The glucose produced is used as an osmolyte or energy source to resist or combat the stress. In stressed fish, changes in hematocrit could be the result of the osmoconcentration of the blood plasma, as shown by the increase in osmolarity for the same group. In cold-stressed fish, a decrease in hemoglobin concentration could be the result of hemodilution by body cell water.

Selective killing of cancer cells based on loss of heterozygosity and normal variation in the human genome: a new paradigm for anticancer drug therapy

Most drugs for cancer therapy are targeted to relative differences in the biological characteristics of cancer cells and normal cells. The therapeutic index of such drugs is theoretically limited by the magnitude of such differences, and most anticancer drugs have considerable toxicity to normal cells. Here we describe a new approach for developing anticancer drugs. This approach, termed variagenic targeting, exploits the absolute difference in the genotype of normal cells and cancer cells arising from normal gene sequence variation in essential genes and loss of heterozygosity (LOH) occurring during oncogenesis. The technology involves identifying genes that are: 1) essential for cell survival; 2) are expressed as multiple alleles in the normal population because of the presence of one or more nucleotide polymorphisms; and 3) are frequently subject to LOH in several common cancers. An allele-specific drug inhibiting the essential gene remaining in cancer cells would be lethal to the malignant cell and would have minimal toxicity to the normal heterozygous cell that retains the drug-insensitive allele. With antisense oligonucleotides designed to target two alternative alleles of replication protein A, 70-kDa subunit (RPA70) we demonstrate in vitro selective killing of cancer cells that contain only the sensitive allele of the target gene without killing cells expressing the alternative RPA70 allele. Additionally, we identify several other candidate genes for variagenic targeting. This technology represents a new approach for the discovery of agents with high therapeutics indices for treating cancer and other proliferative disorders.

CAMPATH-1H (Cambridge University)

CAMPATH-1H, a T-cell-depleting, humanized monoclonal antibody, is under development by LeukoSite and ILEX for the potential treatment of chronic lymphocytic leukemia (CLL). In August 1998, ILEX completed enrollment of a pivotal clinical trial of CAMPATH-1H in the treatment of CLL. The study has enrolled 94 patients at 20 centers in the US and Europe. It is anticipated that achievement of the target response would result in a biologics license application being filed with the FDA in mid-1999. Preliminary unaudited results reported by one of the clinical sites were positive. Additional potential therapeutic areas include vasculitis and multiple sclerosis. Preliminary studies have also shown the antibody may reverse acute renal transplant rejection episodes and be useful in ex vivo purging of bone marrow to remove potentially malignant cells. The US FDA has granted Fast Track designation to CAMPATH. The product has orphan drug status.

Risk factors associated with suicide attempt in young French people

Demographic data, personal and familial characteristics, as well as DSM-III-R-based psychiatric diagnoses were collected in 369 adolescents and young adults aged between 15 and 29 years, referred to an Emergency Department for psychological problems. In total, 60% of them were suicide attempters. Separations before the age of 12 years and depression in the family emerged as the main features distinguishing the suicidal group from the psychiatric control group. Fifty per cent of suicide attempters were repeaters. Fostering during childhood, suicide attempts and depression in the family were found to be risk factors for repeated self-attempts. These results support the view that significant levels of dysfunction, together with increased psychiatric morbidity, especially suicidal behaviour, characterize the families of young self-attempters.

Genome structure and gene content in protist mitochondrial DNAs

Although the collection of completely sequenced mitochondrial genomes is expanding rapidly, only recently has a phylogenetically broad representation of mtDNA sequences from protists (mostly unicellular eukaryotes) become available. This review surveys the 23 complete protist mtDNA sequences that have been determined to date, commenting on such aspects as mitochondrial genome structure, gene content, ribosomal RNA, introns, transfer RNAs and the genetic code and phylogenetic implications. We also illustrate the utility of a comparative genomics approach to gene identification by providing evidence that orfB in plant and protist mtDNAs is the homolog of atp8 , the gene in animal and fungal mtDNA that encodes subunit 8 of the F0portion of mitochondrial ATP synthase. Although several protist mtDNAs, like those of animals and most fungi, are seen to be highly derived, others appear to be have retained a number of features of the ancestral, proto-mitochondrial genome. Some of these ancestral features are also shared with plant mtDNA, although the latter have evidently expanded considerably in size, if not in gene content, in the course of evolution. Comparative analysis of protist mtDNAs is providing a new perspective on mtDNA evolution: how the original mitochondrial genome was organized, what genes it contained, and in what ways it must have changed in different eukaryotic phyla.

The Organelle Genome Database Project (GOBASE)

The taxonomically broad organelle genome database (GOBASE) organizes and integrates diverse data related to organelles (mitochondria and chloroplasts). The current version of GOBASE focuses on the mitochondrial subset of data and contains molecular sequences, RNA secondary structures and genetic maps, as well as taxonomic information for all eukaryotic species represented. The database has been designed so that complex biological queries, especially ones posed in a comparative genomics context, are supported. GOBASE has been implemented as a relational database with a web-based user interface (http://megasun.bch.umontreal.ca/gobase/gobas e.html ). Custom software tools have been written in house to assist in the population of the database, data validation, nomenclature standardization and front-end design. The database is fully operational and publicly accessible via the World Wide Web, allowing interactive browsing, sophisticated searching and easy downloading of data.

Early versus late coronary stenting following acute myocardial infarction: results of the STENTIM I Study (French Registry of Stenting in Acute Myocardial Infarction)

This study was undertaken to determine the feasibility and safety of coronary stenting in acute myocardial infarction (AMI). In AMI, primary percutaneous transluminal coronary angioplasty (PTCA) is accepted as the preferred method of reperfusion for patients presenting at highly experienced centres. Until recently, however, stenting has been avoided during AMI because of a potential high risk of thrombosis. This prospective observational study carried out in 20 centres and included 648 consecutive patients who underwent PTCA with stent implantation for AMI. Of these 648 patients, 269 (41.5%, Group 1) were dilated early (< 24 hr) after the onset of the symptoms (75% treated by direct PTCA) and 379 (58.5%, Group 2) were dilated between 24 hr and 14 days after AMI. Combined therapy with ticlopidin and aspirin was used after the procedure. Bailout stenting occurred more often in Group 1 than in Group 2 (17% vs. 9.5%)(P < 0.05). Angiographic successful stenting was similar in both groups of patients (96% vs. 97%). During the hospital follow-up period, stent thrombosis occurred in eight patients (3%) in Group 1 and in six patients (1.6%) in Group 2 (NS). There was 14 deaths (5.2%) in Group 1 and 11 deaths (3.9%) in Group 2 (NS). After multivariate analysis bailout stenting was identified as the sole predictor of stent thrombosis (P < 0.0001). Vascular access-site complications occurred in six patients (1%) with no difference between the two groups. This study indicates that patients who receive a coronary stent in AMI can be managed safely with antiplatelet therapy. Randomized studies are needed to determine the precise indication for coronary stenting as an adjunct to primary PTCA.

[Prospective study of attempted suicide]

The present study involves a prospective review of all patients who visited the Emergency Psychiatric Service during the period from December, 6, 1993 to June, 5, 1994. A questionnaire was proposed to 1073 subjects (57.2% females; 42.8% males; mean age = 36.6 +/- 0.89). Demographic data, familial and personal characteristics, previous contacts with professional health services, and diagnosis (DSM III-R criteria) were collected. 52% of them were self-attempters, significatively younger (mean age 34.03 +/- 1.14) and more frequently females (61.5%). The parasuicides were more frequent in their families and in their personal past history. The previous contacts with health services (hospitalizations, consultations) were more frequent among patients who were admitted for psychological and/or psychiatric problems. 54% of self-attempters were repeating suicidal patients. There were more depressive disorders, parasuicides and drug/alcohol abuse in their families. A logistic regression analysis (stepwise) revealed the role of these factors in the repetition of parasuicides. This data supports the significance of a better knowledge of the potential significant factors for parasuicide. Preventive measures are necessary.

Relationships between high oxygen extraction fraction in the acute stage and final infarction in reversible middle cerebral artery occlusion: an investigation in anesthetized baboons with positron emission tomography

Studies in humans suggest that regions that show maximal increases in brain oxygen extraction fraction (OEF) in the hours following an ischemic episode are those most vulnerable for infarction and are often, although not always, associated with the final site of infarction. To clarify this issue, we followed the hemodynamic and metabolic characteristics of regions with an initially maximally increased OEF and compared them with the ultimately infarcted region in an experimental stroke model. Positron emission tomography (PET) was used to obtain functional images of the brain prior to and following reversible unilateral middle cerebral artery occlusion (MCAO) in 11 anesthetized baboons. To model early reperfusion, the clips were removed 6 h after occlusion. Successive measurements of regional CBF (rCBF), regional CMRO2 (rCMRO2), regional cerebral blood volume, and regional OEF (rOEF) were performed during the acute (up to 2 days) and chronic (> 15 days) stage. Late magnetic resonance imaging (MRI) scans (co-registered with PET) were obtained to identify infarction. Reversible MCAO produced an MRI-measurable infarction in 6 of 11 baboons; the others had no evidence of ischemic damage. Histological analysis confirmed the results of the MRI investigation but failed to show any evidence of cortical ischemic damage. The lesion was restricted to the head of the caudate nucleus, internal capsule, and putamen. The infarct volume obtained was 0.58 +/- 0.31 cm3. The infarcts were situated in the deep MCA territory, while the area of initially maximally increased OEF was within the cortical mantle. The mean absolute rCBF value in the infarct region of interest (ROI) was not significantly lower than in the highest-OEF ROI until 1-2 days post-MCAO. Cerebral metabolism in the deep MCA territory was always significantly lower than that of the cortical mantle; decreases in CMRO2 in the former region were evident as early as 1 h post-MCAO. In the cortical mantle, the rOEF was initially significantly higher than in the infarct-to-be zone. Subsequently, the OEF declined in both regions. The differences in the time course of changes in CMRO2 and OEF between these two regions, with the eventually infarcted area showing earlier metabolic degradation and in turn decline in OEF, presumably underlie their different final outcomes. In conclusion, following MCAO, the region that shows an early maximal increase in the OEF is both topographically and physiologically distinct from the region with final consolidated infarction if reperfusion is allowed at 6 h. This high OEF, although indicative of a threatened condition, is not an indicator of inescapable consolidated infarction and is thus a situation in which therapy could be envisaged. Whether or not it is at risk of infarction and thus constitutes one target for therapy remains to be seen.

Unilateral eyeball enucleation differentially alters AMPA-, NMDA- and kainate glutamate receptor binding in the newborn rat brain

The aim of the present work was to evaluate the neurochemical effects of early unilateral visual deprivation as a model of impaired visual maturation. For this purpose, binding to the different ionotropic glutamate receptor subtypes was quantified in vision-related and vision-unrelated brain structures of control and unilaterally deprived newborn rats. At post-natal (PN) day 10, male Sprague-Dawley rats underwent either unilateral eyeball enucleation (enucleation group, n = 12) or sham operation (control group, n = 12). In each group, brains were obtained either at post-natal day 20 (n = 6) or post-natal day 30 (n = 6) and processed for quantitative in vitro autoradiography selective for NMDA, kainate, and AMPA glutamate-binding sites, as well as for the presynaptic adenosine A1 receptor as a control of the deafferentation efficacy. In control animals, quantitative autoradiography revealed an increase in NMDA (e.g. +45% in superior colliculus) and kainate receptor binding (e.g. +55% in visual cortex, layer IV) from post-natal day 20 to post-natal day 30, associated with stable levels of AMPA receptor binding, in the vision-related structures. In the deafferented visual structures, monocular enucleation induced a marked decrease in A1 site density (e.g. -38 to -52%, in the superficial layer of superior colliculi, at PN day 20 and PN day 30, respectively) in parallel with a mild increase in both NMDA (e.g. +8 to 9%, in superior colliculi and visual cortex, layer IV at PN day 30, respectively) and AMPA (e.g. +16%, in layer IV of the visual cortex at PN day 30). Superimposed on marked bilateral decreases at PN day 30 in the enucleated rats, kainate receptor binding also revealed a slight but significant decrease (-5%) in the deafferented superior colliculus as compared to the non-deafferented side. The present findings (different time-courses of, and differential effects of deafferentation on, the NMDA, kainate and AMPA glutamate receptor subtypes throughout the visual brain structures) further support the involvement of these receptors in distinctive roles during maturation of the visual system.

Intracoronary stent implantation without ultrasound guidance and with replacement of conventional anticoagulation by antiplatelet therapy. 30-day clinical outcome of the French Multicenter Registry

BACKGROUND

Stenting reduces both acute complications of coronary angioplasty and restenosis rates but increases subacute thrombosis rates and hemorrhagic complications when used with coumadin anticoagulation.

METHODS AND RESULTS

To simplify postcoronary stenting treatment and to reduce these drawbacks, we evaluated the 1-month outcome of a prospective registry of 2900 patients in whom successful coronary artery stenting was performed without coumadin anticoagulation. Patients received 100 mg/d aspirin and 250 mg/d ticlopidine for 1 month. Low-molecular-weight heparin (LMWH) treatment was progressively reduced in four consecutive stages, from 1-month treatment to none. Event-free outcome at 1 month was achieved in 2816 patients (97.1%). Major stent-related cardiac events were subacute closure in 51 patients (1.8%), including death in 12 (0.5%), acute myocardial infarction in 17 (0.6%), and coronary artery bypass graft surgery in 9 (0.3%). Stent thrombosis was more frequent with balloon size of < 3.0 mm (< or = 2.5 mm, 10%; 3.0 mm, 2.3%; > or = 3.5 mm, 1.0%; P < .001), bail-out situations (6.67% versus 1.38%, P < .001), and patients with unstable angina or acute myocardial infarction (2.2% versus 1.12%, P = .02). Bleeding complications that required transfusion, surgical repair, or both occurred in 55 patients (1.9%). Bleeding complications were related to female gender (4.0% versus 1.51%, P < .001), duration of LMWH treatment (3.83% in phase II/III versus 0.69% in phase IV/V, P < .001), sheath size (6F, 0.52%; 7F, 1.04%; > or = 8F, 4.23%; P < .001), bail-out situations (4.76% versus 1.67%, P < .01), and saphenous graft stenting (4.38% versus 1.75%, P = .04).

CONCLUSIONS

These results suggest that poststenting treatment by ticlopidine/aspirin is an effective alternative to coumadin anticoagulation, achieving low rates of subacute closure and bleeding complications. LMWH treatment does not improve subacute reocclusion rates but increases bleeding complications. Furthermore, as bleeding complications were independently related to sheath size, we suggest that stenting with 6F guiding catheters may prevent local complications. Furthermore, the ticlopidine/aspirin combination allows a low-cost stenting strategy without ultrasound assessment of stent deployment and permits short inhospital stay.

[Epidemiological study of patients and suicidal patients admitted to a psychiatric emergency department of a general hospital]

The present study involves a review of all patients who visited the Emergency Psychiatric Service during the period from December, 6, 1993 to June, 5, 1994. A questionnaire was proposed to 1073 subjects (57.2% females; 42.8% males; mean age = 36.6). Demographic data, familial and personal characteristics, previous contacts with professional health services, and diagnosis (DSM III R criteria) were collected. 52% of them were self-attempters, younger than the general population and more frequently females (61.5%). The parasuicides were more frequent in their families and in their personal past history. The previous contacts with health services (hospitalizations, consultations) were more frequent among patients who were admitted for psychological and/or psychiatric problems. 54% of self-attempters were repeating suicidal patients. There were more depressive disorders, parasuicides and drug/alcohol abuse in their families. A logistic regression analysis (stepwise) revealed the role of these factors in the repetition of parasuicides. This study supports the significance of a better knowledge of the potential significant factors for parasuicide. Preventive measures are necessary.

Memory disorders in Alzheimer's disease and the organization of human memory

The Squire and Zola-Morgan parallel organization model of the memory and the Tulving hierarchical model were developed mainly through the study of amnesic patients. The predictions of these two models are different, the first being more open to double dissociations and less restrictive than the second. Alzheimer's Disease is characterized by a differential impairment of the memory systems and by an interindividual variability which may take the form of dissociations between preserved and disturbed abilities in some patients. The objective of this study was to use the memory dysfunctions of patients with AD to test the validity of the two models. Analysis of the group data provided an average profile of memory disturbance consistent both with much of the data given in AD literature and with the two models. Using a multiple single-case strategy, we demonstrated several simple dissociations which are for the greater part compatible with the two models. Two of the dissociations underline the limits of the Tulving model, which otherwise accounts for a lot of results. The study supports the relevance of AD for the understanding of the cognitive architecture of the human memory.

Do changes in oxygen metabolism in the unaffected cerebral hemisphere underlie early neurological recovery after stroke? A positron emission tomography study

BACKGROUND AND PURPOSE

Whether an initial depression of function in the unaffected hemisphere ("transcallosal diaschisis") plays a role in early neurological recovery after acute stroke remains controversial. Previous studies were confounded by lack of acute-stage assessment with follow-up and by the problem of defining a suitable control group, since preexisting stroke risk factors may influence prestroke cerebral metabolism. We evaluated with positron emission tomography (PET) the relationships between unaffected-hemisphere (ie, contralateral) oxygen consumption (cCMRO2) and quantitative neurological assessments (and their respective evolution over time) after ischemic stroke.

METHODS

Among 30 consecutive patients with first-ever middle cerebral artery ischemic stroke studied with the (15)O equilibrium method, we selected all survivors (n=19; mean age, 74.6 years) who were investigated both within the first 18 hours after stroke onset (PET1; mean, 11 +/- 4 hours) and 15 to 30 days later (PET2; mean, 24 +/- 10 days), with each patient serving as his/her own control. Neurological deficits were quantified using Orgogozo's middle cerebral artery scale (N score) at each PET session. Neurological changes were calculated as changes in the N score. A late CT scan coregistered with PET provided infarct topography and volume index.

RESULTS

At PET2, we observed the overall expected neurological recovery. There was a nearly significant trend for a decrease in cCMRO2 from PET1 to PET2, especially for the neocortex (P=.08, F test); in a subgroup of eight patients with large infarcts, this CMRO2 decline was significant (P<.05) in the mirror region to the infarct. There was no significant correlation (Spearman's tests) between acute-stage cCMRO2 and same-day N scores or between changes in cCMRO2 versus changes in N score from PET1 to PET2 (any region). There was a nearly significant trend for lower PET2 cCMRO2 in the subgroup of eight patients with large compared with small infarcts (P=.06).

CONCLUSIONS

We found no evidence for an influence of cCMRO2 on acute-stage neurological deficit or for a role of the unaffected hemisphere in early recovery after acute MCA ischemic stroke. The decline in unaffected-hemisphere metabolism from the acute to the subacute stage in the face of overall clinical recovery appears clinically irrelevant. The fact that the neocortical cCMRO2 at PET2 tended to be lower, and declined significantly from PET1 to PET2 in the mirror region in the subgroup of patients with large infarcts, suggests that this delayed effect represents transcallosal fiber degeneration.

Agraphia in Alzheimer's disease: an independent lexical impairment

This study was conducted to delineate the pattern of the writing impairments in 12 patients with Alzheimer type dementia. The patients performed writing tasks involving regular and irregular words and nonwords given by dictation as well as a decision test composed of printed words and pictures requiring phonologic, lexical, and semantic processing. Writing from dictation demonstrated a predominant, but nonisolated, lexical deficit. In order to better evaluate this lexical disorder, the correlation between the dictation writing scores and the decision task scores was analyzed. No significant correlation was found among scores for irregular words, phonologically plausible errors, and scores of the lexical or semantic decision tasks, but there was a significant correlation among scores for the nonwords, nonphonological spelling errors, and scores of the phonologic decision task using printed words. These results would suggest that the "lexical" deficit in agraphia, i.e., difficulty in retrieval or loss of the spelling representations of words, is independent of the lexical or semantic capacities involved in other modalities.

Prolonged persistence of substantial volumes of potentially viable brain tissue after stroke: a correlative PET-CT study with voxel-based data analysis

BACKGROUND AND PURPOSE

The existence in humans of brain tissue at risk for infarction but potentially viable (eg, the penumbra) remains unproven. One retrospective operational definition of such tissue includes its final infarction despite a relatively preserved or even normal cerebral metabolic rate of oxygen (CMRO2) in the early hours after stroke onset. Although previous positron emission tomography (PET) studies identified tissue whose CMRO2 declined from the acute to the subacute stage, in principle compatible with deteriorating penumbra, they all lacked a coregistered CT scan mapping of final infarct and an objective three-dimensional PET data analysis, while many patients were studied in the subacute (up to 48 hours) phase. We have evaluated whether tissue with CMRO2 ranging above a threshold for presumably irreversible damage in the first 18 hours of middle cerebral artery territory stroke, but below it in the chronic stage, could be retrospectively identified within the final infarct volume.

METHODS

Our data bank comprises 30 consecutive patients with first-ever middle cerebral artery territory stroke prospectively studied with PET within the first 18 hours after clinical onset; the 15O equilibrium method was used to measure cerebral blood flow and CMRO2. All survivors with the following criteria were eligible for the present study: (1) technically adequate chronic-stage PET performed in the same stereotaxic conditions, (2) coregistered CT scan also performed in the chronic stage, and (3) an infarct of sufficient dimension (>16mm diameter) on late CT. Corresponding CT scan cuts and PET slices were exactly realigned, and the outlines of CT hypodensities were superimposed on the corresponding CMRO2 matrix. Infarcted voxels with CMRO2 values less than or greater than 1.40 mL/100 mL per minute (ie, the generally accepted threshold for irreversible damage) were automatically identified and projected on matrices of all other PET parameters and for both PET studies.

RESULTS

Eight patients (mean age, 78 Years) were eligible for the present study. The acute-stage PET study was performed 7 to 17 hours after stroke onset and the chronic-stage PET 13 to 41 days later. Within the final infarct, mean CMRO2 fell significantly from the acute- to the chronic-stage PET study (P<.001). Eventually infarcted voxels with acute-stage CMRO2 values above the threshold were found in each of these eight patients; they were most often situated near the infarct borders and constituted 10% to 52% (mean, 32%) of the final infarct volume. The acute-stage CMRO2 in these voxels ranged up to 4.13 mL/100 mL per minute but fell below 1.40 mL/100 mL per minute in 93% of them at the chronic-stage PET. in 7 of 8 patients the acute-stage mean cerebral blood flow ranged from 10 to 22 mL/100 mL per minute, and the mean oxygen extraction fraction was markedly increased (>0.70) in these voxels, consistent with a penumbral state.

CONCLUSION

In a strictly homogeneous sample of prospectively studied patients, we have identified, up to 17 hours after stroke onset, substantial volumes of tissue with CMRO2 well above the assumed threshold for viability that nevertheless spontaneously evolved toward necrosis. This tissue exhibited penumbral ranges of both cerebral blood flow and oxygen extraction fraction and thus could represent the part of penumbra that might be saved with appropriate therapy.

Early spontaneous hyperperfusion after stroke. A marker of favourable tissue outcome?

To clarify the relationships between early hyperperfusion (i.e. the hallmark of early, efficient recanalization in animal stroke models) and ultimate infarction, we have compared acute-stage perfusion PET images and chronic-stage CT scans in patients with middle cerebral artery (MCA) stroke. We used PET and the oxygen-15 (15O) equilibrium method to obtain cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen consumption (CMRO2) parametric images in 30 consecutive, still symptomatic, first-ever MCA territory stroke patients without sign of haemorrhage at admission CT scan. Each subject was studied twice, first within 5-18 h of stroke onset, and, in survivors, approximately 1 month later; a plain CT scan (co-registered with PET) was performed approximately 1 month after onset. Following initial screening based on acute-stage perfusion images, 10 survivors with focal hyperperfusion in the appropriate MCA territory confirmed by computer were declared eligible. In each patient, the topography and volume of both hyperperfusion and infarction (delineated on late CT scan) were recorded, and all PET parameters were obtained for both areas and both times. The hyperperfused areas affected the cortical MCA territory, often widely so and in a patchy fashion; they were topographically distinct from, and consistently larger than (P < 0.01, Wilcoxon sign test) the final infarcts, which were small and generally deep-seated. In none of the nine patients in whom it was successfully performed did transcranial Doppler reveal MCA stem occlusion. In the hyperperfused regions, the acute-stage perfusion, blood volume and oxygen consumption were significantly increased, and the OEF significantly reduced, while all these variables had significantly returned toward normality in the chronic-stage PET study. The ultimately infarcted area did not exhibit significant hyperperfusion in the acute stage. The areas with acute-stage hyperperfusion exhibited haemodynamic and metabolic abnormalities consistent with post-recanalization hyperperfusion, i.e. vasodilatation and "luxury perfusion'. Increased oxidative metabolism, previously reported only in animals, presumably reflects an overshoot of protein synthesis. The fact that the areas with hyperperfusion, though extensive, were topographically distinct from the infarcted region, suggests that spontaneous non-haemorrhagic hyperperfusion, when documented 5-18 h after onset, is a harmless and even perhaps beneficial phenomenon. These results have implications for clinical trials.

A comprehensive investigation of plasma and brain regional pharmacokinetics of imipramine and its metabolites during and after chronic administration in the rat

The relationship between the serum imipramine concentration and its antidepressant effects remain undefined despite > 30 years of clinical investigation. No study to date has assessed the kinetic relationships between the concentrations of imipramine and its metabolites in plasma and in various brain structures. In this study, we examine the pharmacokinetics of imipramine (IMI) and its desmethylated and hydroxylated metabolites in rats given IMI chronically (20 mg/kg, intraperitoneally twice a day for 14 days). The concentrations in serum, cerebrospinal fluid, and six brain structures were measured by high-performance liquid chromatography at 13 different times from 0.5 to 120 h after the end of treatment. The concentrations of IMI, desipramine (DMI), and didesmethylimipramine (DDMI) in brain tissue were much higher than in the serum; concentrations were maximal at 1-2 h in the serum and the brain, which is indicative of the rapid metabolism of IMI with immediate and massive entry of the metabolites into the brain. The elimination halflives of desmethylated compounds increased with the degree of desmethylation, and DDMI was still present in brain tissue 96 h after the end of treatment. These results suggest that DDMI should be taken into account in clinical investigations of the effects of serum concentrations of IMI. The hydroxylated metabolites 2-OH imipramine (2-OH IMI) and 2-OH desipramine (2-OH DMI) were detected in serum, but not in cerebral tissue. The 10-OH metabolites were detected in both serum and brain, but the antidepressant action of these metabolites have not been clearly established. Finally, there were significant differences in the distributions of IMI and several of its metabolites in brain structures. Such differences may have clinical relevance if they also occur in humans.

Central benzodiazepine receptor occupancy by zolpidem in the human brain as assessed by positron emission tomography

The central benzodiazepine receptor occupancy by zolpidem in man is unknown. The present study used positron emission tomography (PET) and [11C]flumazenil to assess in five healthy volunteers, central benzodiazepine receptor occupancy in brain regions with high receptor densities 1 h following an acute oral administration of twice the usual hypnotic dose of zolpidem (20 mg). Receptor occupancy was measured in five discrete structures (middle frontal gyrus, middle temporal gyrus, posterior occipital cortex, lateral parietal cortex, and cerebellar cortex) and in a large neocortical area as the fractional change in the [11C]flumazenil bound/free ratio for the interval 15-40 min post-administration of the radiotracer. The free-radioligand concentration was estimated from the pons, a reference structure virtually devoid of central benzodiazepine receptor. With individual pons values, mean occupancy was about 21% but with spurious inter-subject variability. With pons values averaged across the five subjects and separately for control and treated condition, the occupancy was (mean +/- S.D.) 27 +/- 11% for the whole neocortex, and ranged from 26 to 29% in the five discrete structures (P < 0.01). By showing hypnotic effect at moderate occupancies, this study directly provides evidence for the full-agonist properties of zolpidem in human.

Sequential studies of severely hypometabolic tissue volumes after permanent middle cerebral artery occlusion. A positron emission tomographic investigation in anesthetized baboons

BACKGROUND AND PURPOSE

In the positron emission tomography literature, markedly hypometabolic brain tissue (oxygen metabolism < 1.3 to 1.7 mL.100 g-1.min-1) has often been equated with irreversible damage in the human brain. By serial positron emission tomography measurements, we investigated the temporal evolution of the volume of severely hypometabolic brain tissue after permanent middle cerebral artery occlusion in anesthetized baboons with, as a perspective, the development of rational therapeutic strategies.

METHODS

Seven anesthetized and ventilated baboons underwent sequential positron emission tomography examinations with the 15O steady-state technique before and 1, 4, 7, and 24 hours and 14 to 29 days after occlusion. In each baboon the infarct volume was calculated by quantitative histological procedures after 19 to 41 days of occlusion.

RESULTS

The sequential measurement of regional oxygen metabolism demonstrated an extension (for > or = 24 hours) of the volume of severely hypometabolic tissue as defined by both absolute and relative metabolic thresholds, and this profile of evolutivity is observed no matter the threshold used. Mean (+/- SEM) infarction volume of 2.4 +/- 0.6 cm3 was comparable to a tissue volume with oxygen consumption < 40% of contralateral metabolism. The volume of hypometabolic tissue was essentially stable at the 1-, 4-, and 7-hour postocclusion studies, increased markedly at the 24-hour study point, and increased even further in the chronic-stage study (on average, 17 days after occlusion). The tissue that eventually displayed a severely hypometabolic state at the final measurement showed a significant decrease of oxygen metabolism and cerebral blood flow at each time analyzed. In that tissue, the oxygen extraction fraction increased significantly at 1 hour (although not thereafter).

CONCLUSIONS

The extension of severely hypometabolic volume after middle cerebral artery occlusion reinforces the concept of a dynamic penumbra and suggests the existence of a relatively large window of therapeutic opportunity in which it may be possible to develop neuroprotective strategies. Our study suggests that maximum infarct volume is determined at some time between 24 hours and 17 days after permanent middle cerebral artery occlusion in anesthetized baboons.

Healthy aging, memory subsystems and regional cerebral oxygen consumption

The present study was designed to search for concomitant age-related changes in memory subsystems, defined according to current structural theories, and resting oxygen consumption in selected brain regions. We have investigated a sample of subjects between 20 and 68 years of age and strictly screened for their good health. We applied in the same subjects a battery of neuropsychological tests selected to investigate several memory subsystems, and high-resolution positron imaging with stereotaxic localization to study a purposely limited number of cerebral structures, selected on a priori hypotheses to match the different memory subsystems. Our results showed significant age-related changes in performance on some tests, consistent with the literature, including an increase in semantic memory and a decrease in both working memory (central executive system) and verbal episodic and explicit memory. There was also an age-related linear decrease in global brain oxygen consumption which regionally reached statistical significance for the neocortical areas and the left thalamus. There was a limited number of significant, age-independent correlations between the raw psychometric test scores and resting regional oxidative metabolism. Consistent with our present understanding of the functional anatomy of memory, the Associate Learning scores (verbal episodic and explicit memory) were positively correlated with left hippocampal and thalamic metabolism. The positive relationships found between right hippocampal metabolism and performance in the Associate Learning and the Brown-Peterson tests were less expected but would be consistent with findings from recent PET activation studies. The results from this investigation are discussed in the light of current knowledge concerning the neuropsychology and the neurobiology of both aging and memory.

Disorders of auditory identification in dementia of the Alzheimer type

Fifteen patients with probable DAT and 18 matched controls were given tests that required the identification of verbal (phonemes and words) and non verbal (sounds and melodies) stimuli. In all tests, DAT patients made significantly more errors than controls. Errors predominated in non verbal tests in both groups. DAT patients (and, to a lesser degree, control subjects) made almost exclusively acoustic errors in word-identification, while errors in the identification of sounds and melodies could be either semantic or acoustic. Some categories of errors were observed predominantly in DAT patients. These results suggest that, in addition to their cognitive impairment, DAT patients have a specific deficiency of central auditory perception.

PET imaging of neocortical monoaminergic terminals in Parkinson's disease

Post-mortem neurochemical studies in Parkinson's disease (PD) have shown that, in addition to the typical nigro-striatal dopamine denervation, there exists a concomitant neocortical monoamine fibre deafferentation (of variable severity) whose role in motor, and especially in associated cognitive and affective impairment, remains elusive. We have extensively examined whether PET imaging with 11C-S-Nomifensine (11C-NMF), a radioligand of the dopamine and norepinephrine presynaptic reuptake sites which has been used so far to investigate the striatum, could provide a method for assessing in vivo the neocortical monoamine terminal loss in PD; previously, this has been a little addressed and controversial issue. To this end, we prospectively selected a highly homogeneous sample of nine non-demented, non-depressed idiopathic PD patients with mild to marked side-to-side asymmetry in motor impairment. In addition to recovering the previously-reported correlations with putaminal 11C-NMF specific uptake asymmetries, the clinical motor asymmetries also significantly correlated in the clinically expected direction to neocortical (especially frontal) 11C-NMF asymmetries, suggesting the monoamine neocortical denervation might play a direct role in motor impairment in PD. These results demonstrate that it is possible to assess in vivo the neocortical monoamine terminal loss, and to elucidate its potential role in the complex cognitive and affective impairment, in both PD and atypical degenerative parkinsonism.

Topographic EEG activations during timbre and pitch discrimination tasks using musical sounds

Successive auditory stimulation sequences were presented binaurally to 18 young normal volunteers. Five conditions were investigated: two reference tasks, assumed to involve passive listening to couples of musical sounds, and three discrimination tasks, one dealing with pitch, and two with timbre (either with or without the attack). A symmetrical montage of 16 EEG channels was recorded for each subject across the different conditions. Two quantitative parameters of EEG activity were compared among the different sequences within five distinct frequency bands. As compared to a rest (no stimulation) condition, both passive listening conditions led to changes in primary auditory cortex areas. Both discrimination tasks for pitch and timbre led to right hemisphere EEG changes, organized in two poles: an anterior one and a posterior one. After discussing the electrophysiological aspects of this work, these results are interpreted in terms of a network including the right temporal neocortex and the right frontal lobe to maintain the acoustical information in an auditory working memory necessary to carry out the discrimination task.

The optimal dosing regimen for citalopram--a meta-analysis of nine placebo-controlled studies

Optimal dosing schedules for an antidepressant drug can only be established during clinical studies in depressed patients. The benefits of antidepressant therapy are usually progressive, and thus patients must be maintained on a particular treatment for at least 3-4 weeks to assess the efficacy of different doses. Meta-analysis, a widely accepted statistical technique which allows the combination of the results of multiple studies, was used to assess the efficacy of several doses of citalopram over nine placebo-controlled clinical trials. Statistically significant differences between citalopram and placebo were found at both the 20 and 40 mg dose levels. The minimal effective dose of citalopram was shown to be 20 mg. However, analysis of patient subgroups revealed a tendency for those patients suffering from severe or recurrent depression to achieve better results with a higher dosage (40 mg), while patients experiencing their first period of depression or with less severe depression responded well to the minimally effective dose of 20 mg.

Contralateral cerebellar hypometabolism: a predictor for stroke outcome?

Contralateral cerebellar hypometabolism (CCH) is a well established remote functional effect of cerebral damage. Because CCH has been reported to be reversible in acute stroke in at least some patients, the value of cerebellar metabolic asymmetry (CbMA; a reflection of the degree of CCH) as a predictor of stroke outcome has been assessed. Measurements of cerebellar oxygen consumption were performed by positron emission tomography (PET) in 16 patients within 5-30 hours of onset of their first ever middle cerebral artery territory stroke, and again 13-56 days later in 12 survivors. The neurological state was quantified at the time of each PET study and at day 60, with both the Mathew and Orgogozo scales. In the early PET study, the CbMAs ranged from around 0% to nearly 50% (individually significant at p < 0.05 in 9/16 patients) but were neither strongly nor consistently correlated with neurological outcome or recovery at day 60. Similarly, the changes in CbMAs from the early to the late PET study were not correlated with the concomitant neurological evolution. At the late PET study, however, there were excellent positive correlations between CbMAs and both neurological status and size of infarction (assessed by CT in the chronic stage). The correlation with neurological status was explained by the correlation with size of infarction. The poor predictive value of CbMAs in the early PET study may be partly because the cerebral metabolic disturbance might still be evolving at this early stage in some cases. Despite this lack of a strong quantitative link between CbMAs at the early PET study and outcome, the outcome was good in all the patients who did not exhibit significant CCH, suggesting that lack of CCH may predict good outcome in acute middle cerebral artery stroke.

[Humoral and cellular immunologic reactions in various forms of chronic psychiatric diseases]

Studies on the status of the immune system in mental disorders have mostly provided contradictory results. For example, some authors have reported dramatic increases of immunoglobulin G in schizophrenic patients, and others a decrease of immunoglobulin G in the same patients. This prompted us to undertake a study on a large cohort of psychiatric patients (120 schizophrenics, 30 manic-depressives, 8 epileptics, 48 cases of Alzheimer and vascular dementia, 23 cases of alcoholic dementia, 14 cases of childhood psychosis, 47 encephalopaths, and 21 chronic alcoholics), all chronically hospitalized. Plasma antitetanus antibodies were assayed in 238 previously immunized patients, the tuberculin test was performed on 302 patients, and the candidine test on 287 patients. Furthermore, 21 patients had an antitetanus vaccine booster injection with antibodies assayed before the injection and one month later, and 31 patients had 2 tuberculin tests with a year or more between them. The results show no major abnormal immune disorders in the patients. Nevertheless some particular features have been found. The first is a very significant relation between the age and the weakness of the immune defences. The second is a large scattering of the blood tetanus antibodies titers in schizophrenic patients, specially in the paranoid subgroup (20.6% of abnormally high or low titers). And the third is the existence of inpredictable variations in the responses when stimulations, or tests, are repeated. These results can raise the hypothesis of a state-dependent component of the immune response in mentally ill patients, but further in, depth studies are needed for better understanding the nature of our findings.

[Clinical trials and good clinical practices. Results of a telephone survey in Basse-Normandie among 867 physicians]

In order to evaluate what doctors think about clinical trials in general, 867 of them practicing in western Normandy were polled by telephone. The majority of the doctors questioned (68.6%) said they were interested in participating in clinical trials. Moreover, a number of them (71.7%) had already taken part in such studies, most of which were non-comparative studies on drugs already on the market. 66.2% of the doctors said they were willing to participate in such trials but only 10% of the doctors questioned knew anything about Good Clinical Practice. Doctors practicing in this part of France appear to know little or nothing about Good Clinical Practice, however, while they are willing to take part in clinical research, they are insistant that trials should be of worthwhile interest.

PET imaging of cerebral perfusion and oxygen consumption in acute ischaemic stroke: relation to outcome

We used positron emission tomography (PET) to assess the relation between combined imaging of cerebral blood flow and oxygen consumption 5-18 h after first middle cerebral artery (MCA) stroke and neurological outcome at 2 months. All 18 patients could be classified into three visually defined PET patterns of perfusion and oxygen consumption changes. Pattern I (7 patients) suggested extensive irreversible damage and was consistently associated with poor outcome. Pattern II (5) suggested continuing ischaemia and was associated with variable outcome. Pattern III (6), with hyperperfusion and little or no metabolic alteration, was associated with excellent recovery, which suggests that early reperfusion is beneficial. This relation between PET and outcome was highly significant (p < 0.0005). The results suggest that within 5-18 h of stroke onset, PET is a good predictor of outcome in patterns I and III, for which therapy seems limited. The absence of predictive value for pattern II suggests that it is due to a reversible ischaemic state that is possibly amenable to therapy. These findings may have important implications for acute MCA stroke management and for patients' selection for therapeutic trials.

Regional cerebral oxygen consumption, blood flow, and blood volume in healthy human aging

Using high-resolution positron emission tomography and the oxygen 15 continuous inhalation method, we examined the changes in cerebral metabolic rate of oxygen, blood flow, blood volume, and oxygen extraction fraction as a function of age in 25 optimally healthy, unmedicated volunteers who ranged in age from 20 to 68 years. Subjects were strictly selected for absence of cerebrovascular risk factors, dementia, or mental disorders; they had neither biological nor clinical abnormalities, and no focal anomaly on computed tomographic scan. Regions of interest were determined according to the anatomical structures defined on corresponding computed tomographic scan cuts obtained using a stereotaxic head-positioning method. This same method was also used for positron emission tomographic imaging. There was no significant effect of aging on PaCO2 values, hematocrit, arterial blood pressure, cholesterol and triglyceride levels, and blood glucose levels. In most cerebral cortex gyri, the cerebral metabolic rate of oxygen significantly decreased with age according to a linear pattern, with the same magnitude (about -6% per decade) in all four lobes and on both sides. This effect of age on cortical cerebral metabolic rate of oxygen persisted when the possible influence of cortical atrophy, gender, and head size were partialled out. In contrast, the white matter, deep gray nuclei, thalamus, and cerebellum were not significantly affected. The cerebral blood volume declined with a similar pattern to cerebral metabolic rate of oxygen, while changes in cerebral blood flow were less significant, presumably because of larger variance of data across subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Thrombi of the right heart. Value of thrombolytic therapy in mobile thrombi]

Seven patients with mobile right heart thrombi, 4 floating and 3 pediculated, were recensed between 1985 and 1990. Two patients were admitted for congestive cardiac failure (Group I) and 5 patients for pulmonary embolism (Group II). Both patients in Group I were treated with heparin without complications. In one case, the size of the thrombus decreased in 10 days whereas, in the second case, it disappeared within 8 days. In Group II, the first patient underwent successful thrombectomy. The other four patients were given thrombolytic therapy (UK = 2, rt-PA = 2) associated with appropriate doses of heparin. In the two patients given UK (3M units the first day followed by 1.2 M units per day for 4 days) the thrombus disappeared in the first 48 hours of treatment. One patient had a recurrent pulmonary embolism after 2 hours' treatment; both patients had a fall in haemoglobin of 3 cg/ml at the second day. The second patient died at the 5th day. In the two patients treated by rt-PA (100 mg/7 hours) the thrombus disappeared within 4 hours of starting therapy. One patient had a probable recurrent pulmonary embolism. Both patients had a fall in haemoglobin of 3 cg/ml at the 2nd day of treatment. Right heart thrombi are rare (168 cases in the literature of which 111 were mobile). The prognosis seems to be related to echocardiographic appearances: mortality of mural thrombi is about 4% compared with 50% in mobile thrombi. Very mobile "worm-like" masses are therapeutic emergencies because of the risk of embolism (about 68%).(ABSTRACT TRUNCATED AT 250 WORDS)