ABSTRACT
BACKGROUND: The effect of blood storage on tissue oxygen delivery has not been clearly defined. Some studies demonstrate reduced microvascular oxygen delivery, whereas others do not. We hypothesize that storage of rat blood will limit its ability to deliver oxygen to cerebral tissue. METHODS: Anaesthetized rats underwent haemorrhage (18 ml kg(-1)) and resuscitation with an equivalent amount of fresh or 7 day stored strain-specific whole blood. Arterial blood gases, co-oximetry, red cell counts and indices, and blood smears were performed. Hippocampal tissue oxygen tension (PBr(O2)), regional cerebral blood flow (rCBF), and mean arterial pressure (MAP) were measured before and for 60 min after resuscitation (n=6). Data [mean (SD)] were analysed by anova. RESULTS: After 7 days, there was a significant reduction in pH, Pa(O2), an increase in Pa(CO2), but no detectable plasma haemoglobin in stored rat blood. Stored red blood cell morphology demonstrated marked echinocytosis, but no haemolysis in vitro. MAP and PBr(O2) in both groups decreased after haemorrhage. Resuscitation with stored blood returned MAP [92 (SD 16) mm Hg] and PBr(O2) [3.2 (0.7) kPa] to baseline, whereas rCBF remained stable [1.2 (0.1)]. Resuscitation with fresh blood returned MAP to baseline [105 (16) mm Hg] whereas both PBr(O2) [5.6 (1.5) kPa] and rCBF [1.9 (0.4)] increased significantly (P<0.05 for both, relative to baseline and stored blood group). There was no evidence of haemolysis in vivo. CONCLUSIONS: Although resuscitation with stored blood restored cerebral oxygen delivery to baseline, fresh blood produced a greater increase in both PBr(O2) and rCBF. These data support the hypothesis that storage limits the ability of RBC to deliver oxygen to brain tissue.
Subject(s)
Blood Preservation/methods , Blood Transfusion , Brain/metabolism , Hemorrhage/therapy , Oxygen/blood , Animals , Blood Pressure , Carbon Dioxide/blood , Cerebrovascular Circulation , Hemorrhage/blood , Hydrogen-Ion Concentration , Male , Microcirculation , Oxygen Consumption , Partial Pressure , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
BACKGROUND AND PURPOSE: The apolipoprotein E4 allele (APOE4) associates with increased dementia risk, and hypertension may associate with mild cognitive deficits. We examined whether nondemented stroke patients with (1) a prestroke history of hypertension and (2) APOE4 were more cognitively impaired at 3 months after stroke. METHODS: A total of 257 participants were genotyped and outcomes from neuropsychological evaluations analyzed using regression. RESULTS: Total Cambridge Assessment for Mental Disorders in the Elderly (CAMCOG) and speed of working memory significantly associated with hypertension. No outcomes significantly associated with APOE4. CONCLUSIONS: Subjects with prestroke hypertension had more impaired global cognition and slower access to information held in working memory.
Subject(s)
Apolipoproteins E/genetics , Cognition Disorders/genetics , Hypertension/genetics , Hypertension/pathology , Stroke/genetics , Stroke/pathology , Age Factors , Aged , Aged, 80 and over , Alleles , Apolipoprotein E2 , Apolipoprotein E4 , Atrial Fibrillation/genetics , Cognition , Diabetes Mellitus, Type 2/genetics , Female , Genotype , Humans , Male , Neuropsychological Tests , Regression Analysis , Sex Factors , Time Factors , Treatment OutcomeABSTRACT
Heart rate variability (HRV) is a sensitive method for the assessment of autonomic function and requires little cooperation from the subject, making it suitable for use in dementia. Preliminary studies have suggested that HRV may be impaired in Alzheimer's disease (AD). HRV has not been studied in vascular dementia (VAD). We investigate autonomic function in AD and VAD, using power spectral analysis of HRV. One hundred and fourteen participants were evaluated (14 AD, 20 VAD and 80 controls). The resting ECG was recorded for 5 min with participants in the supine position. Power spectral analysis used to obtain spectral bands in the very-low-frequency (<0.04 Hz), low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.40 Hz) bands and total spectral power (<0.40 Hz) according to international HRV guidelines. There were no differences in HRV in patients with AD or VAD when compared with controls.
Subject(s)
Alzheimer Disease/physiopathology , Autonomic Nervous System/physiopathology , Dementia, Vascular/physiopathology , Electrocardiography , Heart Rate/physiology , Signal Processing, Computer-Assisted , Aged , Aged, 80 and over , Alzheimer Disease/diagnosis , Dementia, Vascular/diagnosis , England , Female , Fourier Analysis , Humans , Male , Reference ValuesABSTRACT
Heart rate variability is used to assess cardiovascular autonomic function. The cholinesterase inhibitor donepezil potentially affects parasympathetic activity. Twenty participants with Alzheimer's disease or dementia with Lewy bodies were treated with donepezil in a pilot study. Power spectral analysis was used to analyse 5 min of beat-to-beat RR interval data in 15 cases. Heart rate variability was significantly reduced following treatment with donepezil; mainly for high frequency (median changed from 581 to 78 ms2; p = 0.001) but also for total power (median changed from 1,563 to 844 ms2; p = 0.047). Donepezil may adversely influence cardiovascular autonomic control. These results indicate the need for larger controlled trials to further investigate the cardiovascular effects of donepezil.
Subject(s)
Cardiovascular System/drug effects , Cholinesterase Inhibitors/adverse effects , Dementia/drug therapy , Indans/adverse effects , Piperidines/adverse effects , Aged , Autonomic Nervous System/drug effects , Cholinesterase Inhibitors/therapeutic use , Dementia/physiopathology , Donepezil , Female , Heart Rate/drug effects , Humans , Indans/therapeutic use , Male , Pilot Projects , Piperidines/therapeutic use , Regression Analysis , Sampling Studies , Syncope/chemically induced , Syncope/prevention & controlABSTRACT
Hutchinson-Gilford progeria is a very rare syndrome of premature aging and often features many orthopedic abnormalities. This is a case report on a young boy suffering from progeria. His orthopedic history included bilateral talus deformities of the feet, bilateral dislocated hips, pes planus, a fractured femur (which healed without complications), aseptic necrosis in the left nuclear head of the femur, bilateral fixed hip flexion deformities, bone dysplasia, osteoporosis and osteolysis.
Subject(s)
Bone Diseases/etiology , Progeria/complications , Child , Femoral Fractures/etiology , Foot Deformities/etiology , Hip Dislocation/etiology , Humans , MaleABSTRACT
The notion of internal and external control is related to a number of important social psychological concepts such as internalization, alienation, powerlessness, and inner and other directedness. (See, for example, Freud 1923, Seeman 1959, Riesman 1954). As originally developed by Rotter (1966), the concept of internal control refers to a person's perception that events are contingent upon his or her behavior or attributes; external control refers to individuals' perceptions that events are not entirely contingent upon their actions but are the result of luck, chance, or fate, are controlled by powerful others, or are unpredictable because of the great complexity of surrounding forces. While conducting an analysis of the motivations of adult women returning to full-time education, I was forced to deal with the competing claims of these two concepts of control. I will, first, describe the nature of my study. Second, in the process of examining my data, I will critically assess the notion of internal and external control in conjunction with related theories concerning vocabularies of motive and casual attributions. Finally, I will discuss briefly the implications of the findings regarding the potential for social change in modern industrial society.
