Platelets at the Vessel Wall in Non-Thrombotic Disease

Platelets are small, anucleate entities that bud from megakaryocytes in the bone marrow. Among circulating cells, platelets are the most abundant cell, traditionally involved in regulating the balance between thrombosis (the terminal event of platelet activation) and hemostasis (a protective response to tissue injury). Although platelets lack the precise cellular control offered by nucleate cells, they are in fact very dynamic cells, enriched in preformed RNA that allows them the capability of de novo protein synthesis which alters the platelet phenotype and responses in physiological and pathological events. Antiplatelet medications have significantly reduced the morbidity and mortality for patients afflicted with thrombotic diseases, including stroke and myocardial infarction. However, it has become apparent in the last few years that platelets play a critical role beyond thrombosis and hemostasis. For example, platelet-derived proteins by constitutive and regulated exocytosis can be found in the plasma and may educate distant tissue including blood vessels. First, platelets are enriched in inflammatory and anti-inflammatory molecules that may regulate vascular remodeling. Second, platelet-derived microparticles released into the circulation can be acquired by vascular endothelial cells through the process of endocytosis. Third, platelets are highly enriched in mitochondria that may contribute to the local reactive oxygen species pool and remodel phospholipids in the plasma membrane of blood vessels. Lastly, platelets are enriched in proteins and phosphoproteins which can be secreted independent of stimulation by surface receptor agonists in conditions of disturbed blood flow. This so-called biomechanical platelet activation occurs in regions of pathologically narrowed (atherosclerotic) or dilated (aneurysmal) vessels. Emerging evidence suggests platelets may regulate the process of angiogenesis and blood flow to tumors as well as education of distant organs for the purposes of allograft health following transplantation. This review will illustrate the potential of platelets to remodel blood vessels in various diseases with a focus on the aforementioned mechanisms.

Maternal morbidity and mortality: an iceberg phenomenon

OBJECTIVE

To apply the iceberg model, quantifying absolute and relative incidence, to the four main causes of maternal morbidity and mortality in Ireland: haemorrhage, hypertension, sepsis and thrombosis.

DESIGN

Secondary analysis of national data on maternal morbidity and mortality.

SETTING

Republic of Ireland.

POPULATION OR SAMPLE

Approximately 715 000 maternities, 1 200 000 maternal hospitalisations, 2138 cases of severe maternal morbidity (SMM) and 54 maternal deaths.

METHODS

Incidence rates and case-fatality ratios were calculated.

MAIN OUTCOME MEASURES

Maternal death, SMM and hospitalisation.

RESULTS

At the 'tip of the iceberg', the incidence of maternal death per 10 000 maternities was 0.09 (95% CI 0.03-0.20) due to thrombosis and 0.03 (95% CI 0-0.11) due to haemorrhage, hypertension disorders or sepsis. For one death due to thrombosis there were 35 cases of pulmonary embolism and 257 thrombosis hospitalisations. For one death due to eclampsia, there were 58 eclampsia cases, 13 040 hospitalisations with pre-existing hypertension and 40 781 hospitalisations with gestational hypertension. For one death due to pregnancy-related sepsis, there were 92 cases of septicaemic shock and 9005 hospitalisations with obstetric sepsis. For one maternal death due to haemorrhage, there were 1029 cases of major obstetric haemorrhage and 53 715 maternal hospitalisations with haemorrhage. For every 100 maternities, there were approximately 16 hospitalisations associated with haemorrhage, 12 associated with hypertension disorders, three with sepsis and 0.2 with thrombosis.

CONCLUSIONS

Haemorrhage and hypertension disorders are leading causes of maternal morbidity in Ireland but they have very low case fatality. This indicates that these morbidities are managed effectively but their prevention requires more focus.

TWEETABLE ABSTRACT

Study shows that haemorrhage and hypertension are main causes of #maternalmorbidity in Ireland. Timely interventions for #maternalhealth and focus on prevention of severe and non-severe morbidities are needed. @NPEC #maternityservices #clinicalaudit #qualityimprovement.

Automated White Matter Hyperintensity Segmentation Using Bayesian Model Selection: Assessment and Correlations with Cognitive Change

Accurate, automated white matter hyperintensity (WMH) segmentations are needed for large-scale studies to understand contributions of WMH to neurological diseases. We evaluated Bayesian Model Selection (BaMoS), a hierarchical fully-unsupervised model selection framework for WMH segmentation. We compared BaMoS segmentations to semi-automated segmentations, and assessed whether they predicted longitudinal cognitive change in control, early Mild Cognitive Impairment (EMCI), late Mild Cognitive Impairment (LMCI), subjective/significant memory concern (SMC) and Alzheimer's (AD) participants. Data were downloaded from the Alzheimer's disease Neuroimaging Initiative (ADNI). Magnetic resonance images from 30 control and 30 AD participants were selected to incorporate multiple scanners, and were semi-automatically segmented by 4 raters and BaMoS. Segmentations were assessed using volume correlation, Dice score, and other spatial metrics. Linear mixed-effect models were fitted to 180 control, 107 SMC, 320 EMCI, 171 LMCI and 151 AD participants separately in each group, with the outcomes being cognitive change (e.g. mini-mental state examination; MMSE), and BaMoS WMH, age, sex, race and education used as predictors. There was a high level of agreement between BaMoS' WMH segmentation volumes and a consensus of rater segmentations, with a median Dice score of 0.74 and correlation coefficient of 0.96. BaMoS WMH predicted cognitive change in: control, EMCI, and SMC groups using MMSE; LMCI using clinical dementia rating scale; and EMCI using Alzheimer's disease assessment scale-cognitive subscale (p < 0.05, all tests). BaMoS compares well to semi-automated segmentation, is robust to different WMH loads and scanners, and can generate volumes which predict decline. BaMoS can be applicable to further large-scale studies.

Malnutrition in Hospitalised Older Adults: A Multicentre Observational Study of Prevalence, Associations and Outcomes

BACKGROUND

Malnutrition is common in older adults and is associated with high costs and adverse outcomes. The prevalence, predictors and outcomes of malnutrition on admission to hospital are not clear for this population.

DESIGN

Prospective Cohort Study.

SETTING

Six hospital sites (five public, one private).

PARTICIPANTS

In total, 606 older adults aged 70+ were included. All elective and acute admissions to any speciality were eligible. Day-case admissions and those moribund on admission were excluded.

MEASUREMENTS

Socio-demographic and clinical data, including nutritional status (Mini-Nutritional Assessment - short form), was collected within 36 hours of admission. Outcome data was collected prospectively on length of stay, in-hospital mortality and new institutionalisation.

RESULTS

The mean age was 79.7; 51% were female; 29% were elective admissions; 67% were admitted to a medical specialty. Nutrition scores were available for 602/606; 37% had a 'normal' status, 45% were 'at-risk', and 18% were 'malnourished'. Malnutrition was more common in females, acute admissions, older patients and those who were widowed/ separated. Dementia, functional dependency, comorbidity and frailty independently predicted a) malnutrition and b) being at-risk of malnutrition, compared to normal status (p < .001). Malnutrition was associated with outcomes including an increased length of stay (p < .001), new institutionalisation (p =<0.001) and in-hospital mortality (p < .001).

CONCLUSIONS

These findings support the prioritisation of nutritional screening in clinical practice and public health policy, for all patients ≥70 on admission to hospital, and in particular for people with dementia, increased functional dependency and/or multi-morbidity, and those who are frail.

Detailed volumetric analysis of the hypothalamus in behavioral variant frontotemporal dementia

Abnormal eating behaviors are frequently reported in behavioral variant frontotemporal dementia (bvFTD). The hypothalamus is the regulatory center for feeding and satiety but its involvement in bvFTD has not been fully clarified, partly due to its difficult identification on MR images. We measured hypothalamic volume in 18 patients with bvFTD (including 9 MAPT and 6 C9orf72 mutation carriers) and 18 cognitively normal controls using a novel optimized multimodal segmentation protocol, combining 3D T1 and T2-weighted 3T MRIs (intrarater intraclass correlation coefficients ≥0.93). The whole hypothalamus was subsequently segmented into five subunits: the anterior (superior and inferior), tuberal (superior and inferior), and posterior regions. The presence of abnormal eating behavior was assessed with the revised version of the Cambridge Behavioural Inventory (CBI-R). The bvFTD group showed a 17 % lower hypothalamic volume compared with controls (p < 0.001): mean 783 (standard deviation 113) versus 944 (73) mm³ (corrected for total intracranial volume). In the hypothalamic subunit analysis, the superior parts of the anterior and tuberal regions and the posterior region were significantly smaller in the bvFTD group compared with controls. There was a trend for a smaller hypothalamic volume, particularly in the superior tuberal region, in those with severe eating disturbance scores on the CBI-R. Differences were seen between the two genetic subgroups with significantly smaller volumes in the MAPT but not the C9orf72 group compared with controls. In summary, bvFTD patients had lower hypothalamic volumes compared with controls. Different genetic mutations may have a differential impact on the hypothalamus.

Brief assessment of severe language impairments: Initial validation of the Mississippi aphasia screening test

PRIMARY OBJECTIVE

To validate the Mississippi Aphasia Screening Test (MAST) which includes nine sub-scales measuring expressive and receptive language abilities.

RESEARCH DESIGN

Evaluation of inpatients admitted to neurology, neurosurgery or rehabilitation units at two local hospitals and who were within 60 days of onset of a unilateral ischemic or haemorrhagic stroke (left hemisphere (LH; n=38); right hemisphere (RH; n=20)). Additional participants were recruited from the community to comprise a non-patient control sample (NP; n=36).

METHODS

Data collection included administration of the MAST and chart review.

RESULTS

The LH group showed more impairment than the RH and NP groups on summary scores. The LH group performed worse than the NP group on all sub-scales. The object recognition and verbal fluency sub-scales did not discriminate the stroke groups.

CONCLUSION

Analyses suggest good criterion validity for the MAST in differentiating communication impairments among clinical and control samples.

Interleukin-10 delivery via mesenchymal stem cells (MSC) to prevent ischemia/reperfusion injury in lung transplantation (141.46)

Ischemia-reperfusion injury (IR) is an important cause for lung graft loss (~30%). In this study, MSC & viral interleukin-10 (vIL-10) engineered MSC were tested for their ability to prevent lung IR injury. Bone marrow derived MSC from Lewis rat were transduced with rvIL-10-retrovirus & selected on neomycin. Following 120 min of left lung ischemia induction, Group A, rats received vIL-10-MSC (~15 x 106; i.v.); Group B, empty vector engineered MSC; Group C, MSC; Group D, saline; and Group E, no ischemia or MSC. Mean blood oxygenation (PaO2/FiO2 ratio, mmHg) was reduced (P&lt;0.05) at 24h post-IR injury in Group B (138±86; n=9) & Group D (87±39; n=10), compared to MSC-vIL10 (353±105; Group A; n=10) group. By days 3 & 7 with MSC-vIL10 oxygenation was normal (475±55 & 435±33; n&gt;9); by 4h it was 319±94 (n=7). MSC (passage ≤6) increased PaO2/FiO2 (454 ± 59; n=5) by 24h post-IR. Bronchoalveolar lavage at 24h post-MSC-vIL10 therapy reduced (P&lt;0.05) granulocytes, CD4 & CD8 T cells. Lung injury score (histopathology) was higher (P&lt;0.05) with no treatment (3.5 ± 1.3; n=5) compared to MSC-vIL10 (1.21± 0.6; n=7) & MSC (1.6±0.9; n=6) treated groups. Lung microvascular permeability & wet:dry ratio were lower (P&lt;0.05) in MSC-vIL10 group. IL-1α, MCP-1α, MIP-1α, & IL1-β were increased in IR injured lung. ISOL (in situ staining for DNA fragmentation) & CASPACE-3 demonstrated reduced (p&lt;0.05) number of apoptotic cells in MSC-vIL10 treated lungs. Ex vivo, expanded MSC were CD34-, CD31+ & CD45+ (5-10%), CD29+, CD90+ & CD44+ (65-95%), CD80 (0%), CD 86 (8%), MHC Class I+ (23-57%), & MHC Class II-. MSC & IL-10 delivery via MSC to prevent lung transplant IR injury seems promising.

Survival among hospital in-patients with troponin T elevation below levels defining myocardial infarction

BACKGROUND

Cardiac troponin T (cTnT) has an accepted place in the management of patients presenting with suspected acute coronary syndrome (ACS). Uncertainty remains about the significance and interpretation of elevated cTnT below the cut-off levels defining myocardial infarction (0.1 microg/l).

AIM

To compare the mortality risks for elevation of cTnT in the ranges 0.01-0.029 microg/l, 0.03-0.099 microg/l and <0.01 microg/l.

DESIGN

Retrospective record study in three hospitals.

METHODS

All cTnT measurements with values in the range >0.01-0.099 microg/l analysed during January 2002 were extracted from clinical biochemistry laboratory databases. Following agreed exclusion criteria, 179 patients with cTnT in the range 0.01-0.099 microg/l and 60 patients <0.01 microg/l were selected at random from across the three sites. Six-month follow-up was completed by review of case notes and contact with the patients' GP.

RESULTS

There was a graded increase in mortality with increasing cTnT, although only achieving statistical significance for patients in the 0.03-0.099 microg/l range. The graded increase in relative risk with cTnT was weaker after adjustment for potential confounding factors

DISCUSSION

We found a trend for worse survival with increasing cTnT within the range 0.01-0.099 microg/l in unselected patient populations presenting with possible acute coronary syndrome. This suggests that the combined effects of assay imprecision and co-morbidity should be taken into account when interpreting borderline elevation of cTnT. The use of a cut-off based on current standards of assay precision should be used to define the sensitivity of cTnT as biochemical evidence of ischaemic cardiac damage and as an indicator of mortality risk. This level is likely to be between 0.03 and 0.1 microg/l.

'The experience of community mental health case management provided from an acute in-patient psychiatric unit'

In Australia, case management is the cornerstone of mental health service delivery for seriously ill clients living in the community. In this study, case management was provided from an acute, inpatient psychiatric unit; a model thought to be unique. Findings from this qualitative study explicated the experience of case management from client and case manager (CM) perspectives. They note the nature, purpose, processes and outcomes of case management within that context. Findings were positive, suggesting clients and CM's develop a therapeutic alliance through which interventions are implemented and which result in clients experiencing personal (re) integration and enhanced well-being. These findings are discussed and they suggest an alternative model of service delivery well regarded by both clients and CM's.

Paediatric management practices in Down syndrome: a follow-up survey

In a follow-up survey to a 1984 study, 339 paediatricians in Australia were invited to complete a brief questionnaire in 1990, in which they indicated their usual recommendations, practices and advice when managing children with Down syndrome. The response rate was 67%. The results indicated that the most frequent paediatrician-initiated referrals were for early intervention and for discussion with other parents; these options were selected more frequently in 1990 than in 1984. While referral to a social worker was the next most frequent choice, it occurred less in 1990 than in 1984. Other increases in referrals were for physiotherapy and speech therapy. Paediatricians were more likely to support referral to a geneticist, speech therapist or cosmetic surgeon in response to a specific parental enquiry, and less likely to support referral to a social worker or to full-time care. There had been significant increases since 1984 in the likelihood that paediatricians would order audiology and investigation of thyroid and cardiac function. There was less opposition to the use of sedatives, and virtual cessation of the use of tryptophan. Paediatricians were more optimistic about the likelihood of persons with Down syndrome living independently, caring for their own finances, and marrying, but not about other developmental areas.

Sources of satisfaction for nurses

This article completes the reporting of a survey in which 275 nurses were asked to indicate their needs, their sources of stress, and (in the present article) their sources of work satisfaction. A panel of three senior nurses classified the sources of satisfaction into 10 categories. The greatest number of replies proved to be in categories which the panel named Patients, Education and Achievement. The smallest number was in categories called Conditions and Responsibility. These came mainly from nurses in administrative or special positions.

Eyeglasses, height, and lateral eye movements

Conformity to the lateral eye movement patterns of (1) a preferred direction in a face-to-face situation and (2) direction contralateral to the cerebral hemisphere tapped by a question in a nonface-to-face situation was studied in forty right-handed male college students in four groups: (1) Normal vision (N = 10), (2) Nearsighted wearing glasses full-time (N = 10), (3) Nearsighted wearing contact lenses (N = 10), and (4) Nearsighted wearing glasses part-time (N = 10). Subjects were of normal weight with no familial left-handedness or psychiatric hospitalization and no ocular or visual problems other than nearsightedness. Ratings of eye movement direction were made from videotapes. Subjects wearing glasses full-time or part-time were significantly more likely than other subjects to show the contralateral eye movement pattern in the nonface-to-face situation (p less than 0.05). Tall subjects showed more up eye movements (p less than 0.05). These findings were interpreted as an effect of long-standing visual expectancies. Myopic subjects were significantly more likely to be left-lookers than right-lookers (p less than 0.05).

The effects of carbohydrate, fat and total energy adjustment of Fredrickson's type IIb hyperlipoproteinaemia

Fifteen patients with Fredrickson's type IIb hyperlipoproteinaemia were subjected to a 10-week dietary study during which time qualitative and quantitative alterations were carried out on the fat, carbohydrate and energy content of the diet. Significant reduction was observed in fasting serum cholesterol and triglyceride levels on substitution of polyunsaturated for saturated fat, and on total fat restriction. No changes in cholesterol and triglyceride levels were observed when dietary sucrose was replaced with complex carbohydrate, or when there was total carbohydrate restriction. The possible practical applications of these observations are discussed.