Kinetics of In-111-platelets in the baboon: II. In vitro distribution and sites of sequestration

The kinetics and sites of sequestration of a fully representative population of In-111-platelets were determined in 11 baboons. The in vivo method of quantification with computer assisted scintillation camera image analysis was validated by sacrificing 5 baboons and measuring and comparing the distribution of organ radioactivity. Recovery of platelets in the circulation was 87% +/- 7, and their mean survival time was 147 hr +/- 15. The mean splenic platelet pool was 16.0 +/- 1.9. At equilibrium 15.8% +/- 2.9 of the In-111-platelets were in the hepatic blood pool. Senescent platelets were destroyed in the reticulo-endothelial system. The major sites of sequestration were: liver (37.6% +/- 6.0), and the spleen (23.3% +/- 4.6). The bone marrow sequestrated 14.4% +/- 1.7 of the labelled platelets, and 15.5% +/- 4.0 were present in various other tissues. We conclude that the in vivo method of In-111-quantification is accurate. Senescent platelets are mainly sequestrated in the reticuloendothelial tissue, with the liver, spleen and the bone marrow important sites of sequestration.     

Validation of the dual radiotracer method for quantitative In-111 platelet scintigraphy

We have developed a simple in vivo scintigraphic technique that permits accurate quantitative comparison of intravascular platelet deposition in blood vessels of similar size. Regional count information from scintigraphic images of In-111 platelets and Tc-99m red blood cells is used to determine the ratio of radioactivity in the thrombus relative to that in the blood. Multiplication of this ratio by the percent injected dose (%ID) of In-111 per ml of blood yields a quantity (%ID index) that is directly proportional to the %ID of In-111 platelets in the thrombus as measured in vitro (r = .879, p less than 0.005). This technique is well suited for quantitative studies of scintigraphically detectable platelet deposition in both animals and in man.     

Bipolar I and II disorders in a random and representative Australian population

OBJECTIVE: To assess the prevalence of bipolar I and II disorders in an Australian population. METHOD: The Mood Disorder Questionnaire (MDQ) was administered to 3015 respondents in a random and representative sample in South Australia. Health status, quality of life and demographic data were also collected. RESULTS: There was a 2.5% lifetime prevalence of bipolar I and II disorders delineated by the MDQ. Those people had a significantly greater use of services and a poorer health status and quality of life than those who were MDQ-negative. CONCLUSIONS: These results in an Australian population are consistent with other international studies showing a greater prevalence of bipolar disorders than hitherto appreciated.     

Kinetics and in vivo distribution of in-111-labelled platelets and platelet function in familial hypercholesterolaemia

The kinetics, in vivo distribution and sites of sequestration of autologous In-111-labelled platelets and other platelet function parameters were studied in ten patients with type IIa or IIb familial hypercholesterolaemia and thrombotic complications of atherosclerosis. The in vitro platelet aggregation response to ADP (P = 0.50) and collagen (P = 0.46); binding of fibrinogen to platelets (P = 0.61); and plasma beta-thromboglobulin levels (P = 0.42) of the patients and normal reference subjects did not differ significantly. The in vivo distribution of In-111-labelled platelets at equilibrium was within normal limits, and at the end of platelet life-span the sequestration pattern of labelled platelets in the reticuloendothelial system was also normal (spleen P = 0.31; liver P = 0.54). There was minimal evidence of in vivo platelet activation: only mean platelet lifespan (MPLS), 195 +/- 57 hours (difference between mean MPLS of patients and controls was 25 hours, with a 95% confidence interval from 23 to 31 hours; P = 0.02); mean platelet platelet turnover, 2298 +/- 824 platelets/microliter/hour (P = 0.005); plasma platelet factor 4 (P = 0.02); and the mean circulating platelet aggregate ratio, 0.8 +/- 0.1 (P = 0.02); differed significantly from normal. These results suggest that abnormalities of platelet function and kinetics observed in type II hyperlipoproteinaemia cannot be ascribed wholly to the hyperlipidaemia, but may be induced by the associated atherosclerosis.     

Lifetime traumatic experiences and posttraumatic stress disorder in the German population: results of a representative population survey

Only a few European population-based studies on the epidemiology of posttraumatic stress disorder (PTSD) are available to date. This study aims to broaden the epidemiological knowledge of traumatic experiences (TEs), PTSD, and comorbid mental conditions in a representative German sample (N = 2510). The Composite International Diagnostic Interview list of traumatic events, the Posttraumatic Diagnostic Scale, and Patient Health Questionnaire (PHQ)-9 as well as PHQ-15 were used in this survey. Main results were low frequencies of TEs (24%) and PTSD (2.9%). Older participants (>60 years) reported significantly more TEs and more posttraumatic symptoms, whereas there was no significant difference in PTSD prevalence. A third of the subjects diagnosed with PTSD were found positive for depressive syndromes, and 27% were found positive for somatization syndrome. The results show that TEs and posttraumatic symptoms are frequent in senior citizens and thus have to be considered when treating older patients with mental health conditions.     

Predictors of outcome in a representative population of bipolar disorder

Frangou S. Predictors of outcome in a representative population of bipolar disorder. Bipolar Disord 2002: 4(Supp. 1): 41–42. © Blackwell Munksgaard, 2002     

Anxiety disorders and first alcohol use in the general population. Findings from a nationally representative sample

ObjectiveTo examine how early onset anxiety disorders are related to age of first alcohol use in a general population sample.MethodDiscrete time survival analysis was used to model the odds of first alcohol use among those with, vs without, early onset anxiety disorders. Data came from the 2007 Australian National Survey of Mental Health and Wellbeing.ResultsAfter adjusting for the effects of family history of alcohol/drug use, sex, age cohort and education, people who experienced an early onset anxiety disorder had a 27% increased odds of first alcohol use in any given year, when compared to those with no anxiety disorder. This effect was particularly strong for transitions to first alcohol use that occurred after the age of 13 years.ConclusionsEarly onset anxiety disorders significantly predict first alcohol use in the general population and this relationship appears to be related to change over time. These results point to the need for developmentally appropriate and integrated prevention programs that target anxiety and alcohol use together.     

The fetal baboon median eminence as a circumventricular organ: I. Transmission electron microscopy

This investigation has focused upon a set of neuroanatomical correlates that underscore functional changes in the median eminence of the fetal baboon Papio anubis. Eight fetal primate brains were harvested at mid-gestation (100 days post-coitus) and prepared for routine light and transmission election microscopic examination following ventriculo-cisternal perfusion with high osmolarity aldehyde fixatives. The median eminence and other adjacent circumventricular organs (CVO) were blocked and embedded in epon. Routine transmission electron microscopic examination revealed discreet regional differentiation and zonal maturation of the fetal baboon median eminence at 100 days post-coitus. The ependymal and hypendymal zones were anatomically separate from the underlying fibrous and palisade zones of the median eminence. The dominant cell type of the ependymal and hypendymal zones were tanycytes whose apical surfaces constituted the floor of the third cerebral ventricle. The distal processes of tanycytes terminated upon the abluminal basal lamina of well developed perivascular spaces in the contact zone of the fetal median eminence. Numerous axon profiles that harbored both dense core and microvesicles were also observed to terminate upon the system of perivascular spaces that contained numerous fenestrated capillaries. Sharing this common perivascular system were cells of the pars tuberalis that contained numerous secretory inclusions. These data strongly suggest that by mid-gestation the fetal primate median eminence is highly differentiated and may be capable of a wide range of functional activities in response to changes in the maternal-placental environment. The ultrastructural correlates of an active neuroendocrine axis are apparent at this period of development.     

Public knowledge about causes and treatment for schizophrenia: a representative population study

Research on public knowledge about schizophrenia has so far examined various closed questions eliciting recognition-based knowledge rather than unprompted knowledge. We aim to explore the unprompted popular knowledge regarding causes and treatment of schizophrenia. In a representative survey conducted in Germany in 2001 (N = 5025), two open questions asked respondents to name possible causes and treatment options for schizophrenia. Answers were noted down verbatim and later grouped into categories. Psychosocial and biological causal explanations were equally predominant. Respondents recommended drug treatment more frequently than psychosocial measures like psychotherapy, and they mentioned a doctor's visit or a hospital stay most frequently as the adequate treatment setting. About 45% of respondents knew nothing about possible causes or treatments of schizophrenia. Hence, whereas those confidently naming causes or treatment options for schizophrenia favored professional medical treatment more than previously found, overall knowledge about schizophrenia has thus far been overestimated.     

The effect of monoclonal anti-human-platelet antibodies on platelet kinetics in a baboon model: IgG subclass dependency

We assessed the in vivo effect of six intact anti-human antiplatelet antibodies of two major IgG subclasses on platelet kinetics in baboons. Five of the six antibodies tested caused thrombocytopenia of varying degree when injected at a precalculated threshold value. An agglutinating IgG1 antibody (MA-8L4A12) caused a long-lasting, mild thrombocytopenia with a predominant uptake of radiolabelled platelets in the spleen, while the four IgG2 antibodies tested (MA-13G8E1, MA-2M5A6, MA-21K2E8 and MA-22M10) caused a severe, transient thrombocytopenia with uptake of platelets in the liver. Two of the IgG2 antibodies (MA-13G8E1 and MA-2M5A6) caused platelet activation and aggregation in vitro, whilst the other two did not elicit a platelet aggregation response. The platelet survival time was shortened with all five of the thrombocytopenia-inducing antibodies, while only one antibody (MA-2M5A6) had a significant effect on the bleeding time. This study indicates that the IgG subclasss may be a determining factor in the outcome of platelet sequestration in immune-induced thrombocytopenia.     

Stigmatization of psychiatric symptoms and psychiatric service use: a vignette-based representative population survey

European Archives of Psychiatry and Clinical Neuroscience - Background There is evidence for two different types and/or sources of mental illness stigma, namely the display of psychiatric symptoms...     

Prevalence of congenital myopathies in a representative pediatric united states population

The prevalence of congenital myopathies in the United States has not been examined. To address this, we determined the point prevalence of congenital myopathies in a well-defined pediatric population from Southeastern Michigan. The overall point prevalence was 1:26,000. Mutations in RYR1 were the most common cause of congenital myopathies at 1:90,000. Our data broadly agrees with estimates from previous European studies and provides the first estimate of the prevalence of congenital myopathies in the United States. Ann Neurol 2011;70:662-665.     

Effect of aspirin and ticlopidine on platelet deposition in carotid atherosclerosis: assessment by indium-111 platelet scintigraphy

The antiplatelet effects of aspirin and ticlopidine were studied by a dual-tracer method, using indium-111 labeled platelets and technetium-99m human serum albumin, in a group of 12 patients with suspected ischemic cerebrovascular disease. The magnitude of platelet accumulation at the carotid bifurcation was expressed as the ratio of radioactivity of indium-111 platelets deposited on the vascular wall to those circulating in the blood-pool (PAI, platelet accumulation index), 48 hr after injection of labeled platelets. PAI values were measured before (baseline studies) and after the antithrombotic therapies (aspirin studies: 325 mg bid for 22.3 +/- 1.3 days, ticlopidine studies: 100 mg tid for 21.8 +/- 2.1 days). At the baseline, the mean PAI value at 24 carotid bifurcations in the patient group was 15.7 +/- 15.3% (mean +/- S.D.) compared to -4.3 +/- 9.1 at 24 carotid bifurcations in 12 normal subjects (p less than 0.01). We defined the upper limit for a normal PAI (%) value to be +13.9, namely the mean PAI plus 2 SD for the carotid bifurcation in normal subjects and used this value for semiquantitative analysis. At the baseline, significant elevation of PAI (more than 13.9%; positive scintigram) was observed at 12 of 24 vessels, while 12 other regions were negative (less than 13.9%). In the lesions with positive scintigraphic results at the baseline, the mean PAI (%) value from the baseline, aspirin and ticlopidine studies was 29.5 +/- 7.0, 11.2 +/- 8.5 (p less than 0.01 versus baseline) and 21.4 +/- 21.3 (not significant from baseline), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acceptance of community psychiatry reform in the population. Results of a representative study in new German federal lands

In 1993, a representative survey on the acceptance of community psychiatric services was conducted in the New German L?nder. Its results show that the prospect of a hostel or group home for psychiatric patients to be established in their neighbourhood led to a predominantly negative reaction. On the other hand, the announcement that a day centre or a sheltered workshop should be opened was met with a more positive response. Only one quarter of those questioned supported the establishment of psychiatric units at general hospitals. Hence the acceptance of community psychiatric services in the east was clearly lower that in the western part of Germany. There was a clear association between the acceptance of community psychiatry and the general attitude towards the mentally ill. When respondents had personal experience with mental disorder, they were more open-minded as regards the establishment of complementary psychiatric services.     

Kinetics of diffusion in a spherical cell. I. No solute buffering.

Realistic neuron models that involve effects of concentration changes of second messengers on ion channels must include processes such as diffusion and solute buffering. These processes, which span a wide range of spatial and temporal scales, may impose a severe computational burden. In this paper and its companion, we examine the kinetics of diffusion and present methods for stimulating it accurately and efficiency. The problem of calcium diffusion in a spherical cell is used as a device to demonstrate the practical application of our analysis. However, the scope of these papers is not limited to this problem. The same analysis that we apply and concerns that we raise are germane to the spread of any second messenger, and can be adapted to other geometries. The focus of this paper is the simplest case: diffusion in the absence of solute buffering. This analysis also applies whenever buffering is so fast that it is instantaneous compared to diffusion, or so slow that concentration gradients have dissipated before substantial buffering takes place. The second paper investigates the more difficult situation where diffusion and buffering occur at comparable rates. In the absence of buffering, concentration changes produced by diffusion can be fit by an infinite series of exponential terms. We show how to design a model with N + 1 compartments that fits the N slowest terms of this series exactly in a shell just inside the cell membrane.     

Relationship between stress coping and sleep disorders among the general Japanese population: a nationwide representative survey

ObjectiveTo clarify the prevalence of stress, and examine the relationship between sleep disorders and stress coping strategies among highly stressed individuals in the general Japanese population.MethodsA cross-sectional nationwide survey was undertaken in November 2007. Men and women were randomly selected from 300 districts throughout Japan. Data from 7671 (3532 men (average age 53.5 ± 17.0 years) and 4139 women (average age 53.9 ± 17.7 years)) were analyzed. Participants completed a self-reported questionnaire on stress, sleep disorders, and stress coping strategies in the previous month.ResultsHighly stressed individuals comprised 16.6% (95% confidence interval 15.8–17.5%) of the total sample, and most were aged 20–49 years. In multiple logistic regression, symptoms of insomnia (ie, difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening), excessive daytime sleepiness, nightmares, daytime malfunction, and lack of rest due to sleep deprivation were more prone to occur in highly stressed individuals. In addition, logistic regression analysis controlling for other adjustment factors revealed that stress coping strategies such as ‘giving up on problem-solving’, ‘enduring problems patiently’, ‘smoking’ and ‘drinking alcohol’ were positively associated with the above-mentioned sleep disorders. On the other hand, stress coping strategies such as ‘exercising’, ‘enjoying hobbies’, and ‘sharing worries’ were inversely associated with the above-mentioned sleep disorders.ConclusionsDistraction-based stress coping (eg, hobbies, exercise, and optimistic thinking) was found to be preferable to problem-based stress coping in a highly stressed Japanese general population.     

Sex differences in the course of depression: evidence from a longitudinal study of a representative sample of the Belgian population

Outcome studies of major depression indicate high rates of relapse and chronicity, and social role theories imply that chronicity should be greater for women, together suggesting that the well-known sex difference in depression is, at least partially, the result of differences in chronicity. Due to a lack of prospective, longitudinal research, answers to this empirical question are missing. Furthermore, the results of the few available surveys of the general population are inconsistent, showing either higher chronicity for older women or a lack of sex differences in the overall course of depression. Using data from three waves of the Panel Study of Belgian Households (complete data for 3204 women and 2907 men, aged 16 years and older) sex differences in the persistence of depressive behavior are estimated. Depression is measured using a self-report inventory on three occasions separated by intervals of 1 year (1992, 1993, 1994). Results show a significant influence of sex, other sociodemographic characteristics, and depression severity at baseline on depression persistence. Women experience more symptoms for a longer period of time, a difference that can be partially ascribed to sex differences in employment status, education, and marital status. The findings are discussed. Accepted: 30 January 1998