Signal processing for a laser-Doppler blood perfusion meter

Two signal processing methods for laser-Dopper perfusion velocimetry are presented. The methods are based on the calculation of the moments of the frequency power spectrum. The first uses Vω-filtering (ω is the frequency) with analogous electronics, the second uses signal autocorrelation with digital electronics. Comparison is made with a third instrument: a spectrum analyzer coupled to a computer, using Fourier transform tecniques. The performance of these setups (sensitivity, limit sensitivity and accuracy) are investigated. We propose a calibration standard for signal processors to be used for blood perfusion measurements. The analogous instrument proved to be the cheapest but the digital instrument had the best performance

Cerebral white matter lesions and perceived cognitive dysfunction: the role of pregnancy

ObjectiveWomen who suffered eclampsia or preterm preeclampsia are twice as likely to demonstrate cerebral white matter lesions (WML) on magnetic resonance imaging compared with age-matched women who had normotensive pregnancies, and they report more cognitive dysfunctions in everyday life. We aimed to determine whether pregnancy in and of itself has a relationship with the presence of WML and subjective cognitive dysfunction.Study DesignEighty-one parous women who had a normotensive pregnancy were matched for age with 65 nulliparous women and all underwent cerebral magnetic resonance imaging. Presence of cerebral WML was rated and blood pressure was measured. Subjective cognitive functioning was assessed using the Cognitive Failures Questionnaire.ResultsThere was no difference in the presence (22% vs 19%) of WML between parous and nulliparous women. Age was a predictor for the presence of WML, whereas the presence of current hypertension was not. Average score on the Cognitive Failures Questionnaire was not different between both groups, nor related to WML.ConclusionA history of pregnancy in and of itself is not related to the presence of cerebral WML and the perception of cognitive dysfunction. Because of the relationship with preterm preeclampsia and eclampsia, future research should focus on the clinical importance and development throughout the years of such cerebral WML in young women and focus on risk factors for cardiovascular disease

Cerebral white matter lesions, subjective cognitive failures, and objective neurocognitive functioning:A follow-up study in women after hypertensive disorders of pregnancy

OBJECTIVE: Hypertensive disorders of pregnancy, like preeclampsia, are a leading cause of maternal and fetal morbidity/mortality worldwide. Preeclampsia can be complicated by the occurrence of convulsions (eclampsia). Women who experienced (pre)eclampsia more frequently report daily cognitive failures and showed increased emotional dysfunction several years later, but are not impaired on objective neurocognitive testing. In addition, women with preterm preeclampsia more often have cerebral white matter lesions (WML) on follow-up. We aimed to determine whether WML presence is related to cognitive dysfunction, anxiety, and depressive symptoms in (pre)eclamptic women. METHOD: Forty-one eclamptic, 49 preeclamptic, and 47 control women who had a normotensive pregnancy completed the Cognitive Failures Questionnaire (CFQ), the Hospital Anxiety and Depression Scale (HADS), and a broad neurocognitive test battery (visual perception and speed of information processing, motor functions, working memory, long-term memory, attention, and executive functioning). All underwent cerebral magnetic resonance imaging (MRI), and WML presence was recorded. Median elapsed time since index pregnancy was 6 years. Average age was 40 years. RESULTS: WML were more prevalent in women who had experienced preterm (pre)eclampsia (<37 weeks; 40%) than in controls (21%, p = .03). In (pre)eclamptic women, CFQ and HADS scores were higher than those in controls (44± 16.1 vs. 36± 11.0, p < .001, and 11± 6.3 vs. 8± 5.5, p < .001). There was no difference in objective cognitive performance as measured by neurocognitive tests. Subjective and objective cognitive functioning, anxiety, and depressive symptoms were not related to WML presence. CONCLUSION: Formerly (pre)eclamptic women report cognitive dysfunction, but do not exhibit overt cognitive impairment when objectively tested on average 6 years following their pregnancy. The presence of WML is not related to objective nor to subjective cognitive impairment, anxiety, and depressive symptoms. Longitudinal studies are needed to study whether the presence of WML is a risk factor for developing objective cognitive impairment in the long term

Long-term sequelae of severe acute kidney injury in the critically Ill patient without comorbidity: A retrospective cohort study

Background and Objectives: Acute kidney injury (AKI) necessitating renal replacement therapy (RRT) is associated with high mortality and increased risk for end stage renal disease. However, it is unknown if this applies to patients with a preliminary unremarkable medical history. The purpose of this study was to describe overall and renal survival in critically ill patients with AKI necessitating RRT stratified by the presence of comorbidity. Design, Setting, Participants, and Measurements: A retrospective cohort study was performed, between 1994 and 2010, including all adult critically ill patients with AKI necessitating RRT, stratified by the presence of comorbidity. Logistic regression, survival curve and cox proportional hazards analyses were used to evaluate overall and renal survival. Standardized mortality rate (SMR) analysis was performed to compare long-term survival to the predicted survival in the Dutch population. Results: Of the 1067 patients included only 96(9.0%) had no comorbidity. Hospital mortality was 56.6% versus 43.8% in patients with and without comorbidity, respectively. In those who survived hospitalization 10-year survival was 45.0% and 86.0%, respectively. Adjusted for age, sex and year of treatment, absence of comorbidity was not associated with hospital mortality (OR=0.74, 95%-CI=0.47-1.15), while absence of comorbidity was associated with better long-term survival (adjusted HR=0.28, 95%-CI = 0.14-0.58). Compared to the Dutch population, patients without comorbidity had a similar mortality risk (SMR=1.6, 95%-CI=0.7-3.2), while this was increased in patients with comorbidity (SMR=4.8, 95%-CI=4.1-5.5). Regarding chronic dialysis dependency, 10-year renal survival rates were 76.0% and 92.9% in patients with and without comorbidity, respectively. Absence of comorbidity was associated with better renal survival (adjusted HR=0.24, 95%-CI=0.07-0.76). Conclusions: While hospital mortality remains excessively high, the absence of comorbidity in critically ill patients with RRT-requiring AKI is associated with a relative good long-term prognosis in those who survive hospitalization

Long-Term Visual Functioning After Eclampsia

OBJECTIVE: Complete neurocognitive recovery after eclampsia has been questioned with the expression of neurocognitive deficits by affected women and demonstration of cerebral white matter lesions on magnetic resonance imaging years after eclampsia. We hypothesized that formerly eclamptic women may experience impaired vision-related quality of life (QOL) and visual field loss as a result of the presence of such lesions in the cerebral visual areas. METHODS: Using the National Eye Institute Visual Function Questionnaire-39/Nederlands questionnaire, vision-related QOL was compared between formerly eclamptic women and control participants after normotensive pregnancies. Furthermore, in formerly eclamptic women, visual fields were assessed using automated perimetry, and presence of white matter lesions was evaluated using cerebral magnetic resonance imaging. Presence of a relationship between these lesions and National Eye Institute Visual Function Questionnaire-39/Nederlands scores was estimated. RESULTS: Forty-seven formerly eclamptic women and 47 control participants participated 10.1 +/- 5.2 and 11.5 +/- 7.8 years after their index pregnancy, respectively. Composite scores and 4 out of 12 National Eye Institute Visual Function Questionnaire-39/Nederlands subscale scores were significantly lower in formerly eclamptic women than in control participants (P CONCLUSION: Formerly eclamptic women express lower vision-related QOL than control participants, which seemed at least partly related to the presence of white matter lesions. However, such women do not have unconscious visual field loss. Vision-related QOL impairment expressed by formerly eclamptic women may therefore be related to problems with higher-order visual functions

A NOS1AP gene variant is associated with a paradoxical increase of the QT-interval shortening effect of digoxin

Digoxin is characterized by a small therapeutic window and a QT-interval shortening effect. Moreover, it has been shown that the genetic variants of the nitric oxide synthase-1 adaptor protein (NOS1AP) gene are associated with QT-interval prolongation. We investigated whether the rs10494366 variant of the NOS1AP gene decreases the QT-interval shortening effect of digoxin in patients using this drug. We included 10,057 individuals from the prospective population-based cohort of the Rotterdam Study during a median of 12.2 (interquartile range (IQR) 6.7-18.1) years of follow-up. At study entry, the mean age was 64 years and almost 59% of participants were women. A total of 23,179 ECGs were longitudinally recorded, of which 334 ECGs were from 249 individuals on digoxin therapy. The linear mixed model analysis was used to estimate the effect of the rs10494366 variant on the association between digoxin use and QT-interval duration, adjusted for age, sex, RR interval, diabetes, heart failure, and history of myocardial infarction. In non-users of digoxin, the GG genotype was associated with a significant 6.5 ms [95% confidence interval (CI) 5.5; 7.5] longer QT-interval duration than the TT variant. In current digoxin users, however, the GG variant was associated with a significantly -23.9 [95%CI -29.5; -18.5] ms shorter mean QT-interval duration than in those with the TT variant with -15.9 [95%CI -18.7; -13.1]. This reduction was strongest in the high digoxin dose category [≥0.250 mg/day] with the GG genotype group, with -40.8 [95%CI -52.5; -29.2] ms changes compared to non-users. Our study suggests that the minor homozygous GG genotype group of the NOS1AP gene rs10494366 variant is associated with a paradoxical increase of the QT-interval shortening effect of digoxin in a population of European ancestry

Diffusion model for iontophoresis measured by laser-Doppler perfusion flowmetry, applied to normal and preeclamptic pregnancies

We present a physical model to describe iontophoresis time recordings. The model is a combination of monodimensional material diffusion and decay, probably due to transport by blood flow. It has four adjustable parameters, the diffusion coefficient, the decay constant, the height of the response, and the shot saturation constant, a parameter representing the relative importance of subsequent shots (in case of saturation). We test the model with measurements of blood perfusion in the capillary bed of the fingers of women who recently had preeclampsia and in women with a history of normal pregnancy. From the fits to the measurements, we conclude that the model provides a useful physical description of the iontophoresis process. (c) 2007 Society of Photo-Optical Instrumentation Engineers.</p

Porphyromonas Gingivalis and E-coli induce different cytokine production patterns in pregnant women

OBJECTIVE: Pregnant individuals of many species, including humans, are more sensitive to various bacteria or their products as compared with non-pregnant individuals. Pregnant individuals also respond differently to different bacteria or their products. Therefore, in the present study, we evaluated whether the increased sensitivity of pregnant women to bacterial products and their heterogeneous response to different bacteria was associated with differences in whole blood cytokine production upon stimulation with bacteria or their products. METHODS: Blood samples were taken from healthy pregnant and age-matched non-pregnant women and ex vivo stimulated with bacteria or LPS from Porphyromonas Gingivalis (Pg) or E-coli for 24 hrs. TNFα, IL-1ß, IL-6, IL-12 and IL-10 were measured using a multiplex Luminex system. RESULTS: We observed a generally lower cytokine production after stimulation with Pg bacteria or it's LPS as compared with E-coli bacteria. However, there was also an effect of pregnancy upon cytokine production: in pregnant women the production of IL-6 upon Pg stimulation was decreased as compared with non-pregnant women. After stimulation with E-coli, the production of IL-12 and TNFα was decreased in pregnant women as compared with non-pregnant women. CONCLUSION: Our results showed that cytokine production upon bacterial stimulation of whole blood differed between pregnant and non-pregnant women, showing that the increased sensitivity of pregnant women may be due to differences in cytokine production. Moreover, pregnancy also affected whole blood cytokine production upon Pg or E-coli stimulation differently. Thus, the different responses of pregnant women to different bacteria or their products may result from variations in cytokine production