Cuff-less blood pressure estimation using wrist photoplethysmography.

One of the most promising and at the same time rapidly growing sectors in healthcare is that of wearable medical devices. Population ageing constantly shifts towards a higher number of senior and elderly people with increased prevalence of chronic diseases often requiring long-term care and a need to decrease hospitalization time and cost. However, today most of the devices entering the market are not standardized nor medically approved, and they are highly inaccurate. In this work we present a system and a method to provide accurate measurement of systolic and diastolic blood pressure (BP) based solely on wrist photoplethysmography. We map morphological features to BP values using machine learning and propose ways to select high quality signals leading to an accuracy improvement of up to 33.5%, if compared against no signal selection, a mean absolute error of 1.1mmHg in a personalized scenario and 8.7mmHg in an uncalibrated leave-one-out scenario.

Nonuremic calciphylaxis precipitated by teriparatide [rhPTH(1-34)] therapy in the setting of chronic warfarin and glucocorticoid treatment.

Calciphylaxis occurs rarely in the absence of end stage renal disease. Predisposing factors for nonuremic calciphylaxis (NUC) include hyperparathyroidism, coagulopathies, connective tissue disease, liver disease, glucocorticoid use, and malignancy. Warfarin can facilitate vascular calcification by reducing vitamin K-dependent carboxylation of matrix-Gla proteins. An 86-year-old Caucasian woman with a history of polymyalgia rheumatica, two spontaneous deep venous thromboses (DVTs) and multiple fractures was treated with calcium, vitamin D, prednisone, and warfarin. The patient's low bone density was treated initially with estrogen, then oral bisphosphonate, which was discontinued due to upper gastrointestinal symptoms. Nasal calcitonin was initiated. After 10 years of calcitonin treatment, she was changed to teriparatide. Two months after initiating teriparatide, she developed lower extremity edema and painful erythematous nodular lesions on her calves bilaterally, that progressed to necrotic ulcers despite antibiotic therapy. Biopsy of the lesions showed calcification in the media of small blood vessels and subcutaneous fat with fat necrosis, consistent with calciphylaxis. Teriparatide was discontinued. Aggressive wound care, antibiotics, and intravenous zoledronic acid were initiated. With cessation of teriparatide therapy and intensive wound care, the patient's lesions resolved over 8 months. We report the first case of NUC precipitated by teriparatide therapy. Our patient had multiple underlying predisposing factors including a connective tissue disorder, glucocorticoid therapy, warfarin use, and possible underlying coagulopathy given her history of multiple DVTs. In such patients, alternative osteoporosis therapies may be preferred.

Polymer-nanotube composite mats with improved field emission performance and stability.

The results of electron field emission from single walled carbon nanotubes (SWCNTs) mats deposited on different composite films of SWCNTs and poly(3-octylthiophene) (P3OT) semiconducting polymer are presented. Three different structures were tested: (a) dense and sparse SWCNT mats on n+ -Si; (b) SWCNT mats on composite films with different SWCNT-P3OT ratios; (c) composite films with different SWCNT-P3OT ratios on n+ -Si. The experiments show that there is a critical SWCNT-P3OT concentration in which the field emission stability of SWCNT mats is remarkably improved with a small reduction in the emission threshold compared to the optimum pristine SWCNT film. The contribution of the composite film morphology as well as the role of polymer-nanotube interaction on the emission performance are evaluated. The physical mechanism behind the stability of composite field emitters is also discussed.

High prevalence of metabolic syndrome and cardiovascular risk factors in men with ankylosing spondylitis on anti-TNFalpha treatment: correlation with disease activity.

OBJECTIVE: Ankylosing spondylitis (AS) may be associated with an increased risk for cardiovascular diseases (CVD). We investigated the prevalence of cardiovascular risk factors and metabolic syndrome (MetS) in men with AS and assessed any correlation with AS-related factors. METHODS: This was a cross-sectional study of 63 men with AS, median age 40 (19-69) years, and 126 age-matched controls. Patients were on anti-TNFalpha treatment because of considerable disease activity at some time during the course of the disease. MetS was assessed according to the modified National Cholesterol Education Program Adult Treatment Panel III criteria. The risk for CVD event within the next 10 years was estimated using the Framingham equation. RESULTS: Patients had lower high-density lipoprotein cholesterol (HDL-C) (p<0.001), higher systolic (p=0.001) and diastolic (p<0.01) blood pressure compared with controls. The prevalence of the MetS was higher in patients compared to controls (34.9% vs. 19.0%; p<0.05). AS patients with MetS were older (p<0.01), with higher Framingham risk score (p=0.001), had longer disease duration (p<0.05) and higher BASDAI (5.1 vs. 3.7; p<0.05) than those without MetS, while both BASFI and CRP had an inverse correlation with HDL-C levels. CONCLUSIONS: Men with AS have a higher prevalence of cardiovascular risk factors and MetS compared with controls. The presence of MetS was associated with increased 10 year CVD risk in these patients. The association of AS disease activity with MetS suggests that CVD in AS patients may, at least in part, be attributed to the inflammatory burden of the disease.

Metabolic syndrome is common among middle-to-older aged Mediterranean patients with rheumatoid arthritis and correlates with disease activity: a retrospective, cross-sectional, controlled, study.

OBJECTIVES: Patients with rheumatoid arthritis have an increased risk for cardiovascular disease (CVD). The prevalence of metabolic syndrome (MetS)-a major contributor to CVD-in a cohort of patients with rheumatoid arthritis and its relationship with rheumatoid arthritis related factors is investigated here. METHODS: 200 outpatients with rheumatoid arthritis (147 women and 53 men), with a mean (standard deviation (SD)) age of 63 (11) years, and 400 age and sex-matched controls were studied. MetS was assessed according to the adult treatment panel III criteria and rheumatoid arthritis disease activity by the disease activity score of 28 joints (DAS28). A standard clinical evaluation was carried out, and a health and lifestyle questionnaire was completed. RESULTS: The overall prevalence of MetS was 44% in patients with rheumatoid arthritis and 41% in controls (p = 0.5). Patients with rheumatoid arthritis were more likely to have low high-density lipoprotein cholesterol compared with controls (p = 0.02), whereas controls were more likely to have increased waist circumference or raised blood pressure (p = 0.001 and 0.003, respectively). In multivariate logistic regression analysis adjusting for demographics and rheumatoid arthritis treatment modalities, the risk of having moderate-to-high disease activity (DAS28>3.2) was significantly higher in patients with MetS compared with those with no MetS components (OR 9.24, 95% CI 1.49 to 57.2, p = 0.016). CONCLUSION: A high, albeit comparable to the control population, prevalence of MetS was found in middle-to-older aged patients with rheumatoid arthritis. The correlation of rheumatoid arthritis disease activity with MetS suggests that the increased prevalence of coronary heart disease in patients with rheumatoid arthritis may, at least in part, be attributed to the inflammatory burden of the disease.

Microplate array diagonal gel electrophoresis for mutation research in DNA banks.

Molecular genetic epidemiology, association and linkage studies in populations, human or other species, is now yielding powerful new insights into disease and susceptibility genes. Inter alia, the subject requires laboratory analytical methodologies focused on achieving high throughput. Here we review one suite of methodology suitable for such laboratories. Microplate array diagonal gel electrophoresis (MADGE) was invented for molecular genetic epidemiological studies. It combines direct compatibility with microplates, convenient polyacrylamide gel electrophoresis and economy of time and reagents, at minimal capital cost, and enables one user to run up to several thousand gel lanes per day for direct assay of single-base variations. Melt-MADGE combines temporal thermal ramp apparatus to achieve similar throughput for de novo mutation scanning.

Microplate array diagonal gel electrophoresis (MADGE), CpG-PCR and temporal thermal ramp-MADGE (Melt-MADGE) for single nucleotide analyses in populations.

Important requirements for molecular genetic epidemiological studies are economy, sample parallelism, convenience of setup and accessibility, goals inadequately met by existent approaches. We invented microplate array diagonal gel electrophoresis (MADGE) to gain simultaneously the advantages of simple setup, 96-well microplate compatibility, horizontal electrophoresis, and the resolution of polyacrylamide. At essentially no equipment cost (one simple plastic gel former), 10-100-fold savings on time for sample coding, liquid transfers, and data documentation, in addition to volume reductions and gel re-use, can be achieved. MADGE is compatible with ARMS, restriction analysis and other pattern analyses. CpG-PCR is a general PCR approach to CpG sites (10-20% of all human single base variation): both primers have 3' T, and are abutted to the CpG, forcing a TaqI restriction site if the CpG is intact. Typically, a 52 bp PCR product is then cut in half. CpG-PCR also illustrates that PAGE-MADGE readily permits analysis of 'ultrashort' PCRs. Melt-MADGE employs real-time-variable-temperature electrophoresis to examine duplex mobility during melting, achieving DGGE-like de novo, mutation scanning, but with the conveniences of arbitrary programmability, MADGE compatibility and short run time. This suite of methods enhances our capability to type or scan thousands of samples simultaneously, by 10-100-fold.

Microplate-array diagonal-gel electrophoresis (MADGE) and melt-MADGE: tools for molecular-genetic epidemiology.

Microplate-array diagonal-gel electrophoresis (MADGE) was invented for molecular-genetic epidemiological studies. It combines direct compatibility with microplates, convenient polyacrylamide-gel electrophoresis and economy of time and reagents at minimal capital cost, and enables one user to run up to several-thousand gel lanes per day for the direct assay of single-base variations. Melt-MADGE adds temporal-thermal-ramp apparatus to achieve similar throughput for de novo mutation scanning.

Discrimination of fibroblast subtypes by multivariate analysis of gene expression.

Fibroblasts and myofibroblasts from normal, fibrotic or tumoral breast tissues present multiple quantitative differences in gene expression even when grown in isolation. We were therefore prompted to investigate whether one could recognize various subtypes by their constitutive-gene expression profile. Quantitative autoradiographic data for 34 constitutively expressed transcripts were submitted to multivariate analysis of variance, followed by discriminant analysis and single linkage cluster analysis. Models assuming up to 8 putative fibroblast subtypes (among fibroblasts or myofibroblasts from breast skin, normal mammary stroma, tumor-adjacent "normal" stroma, post-radiation fibrosis lesions and benign or malignant tumors) and an epithelial-cell group used as an internal control resulted in 100% correct classification. Myofibroblasts from various origins clustered close to, although distinctly apart from, their corresponding alpha-smooth-muscle-actin-negative counterparts. Malignant tumor fibroblasts were phenotypically more distant from normal cells compared with other pathological types. Our results support the hypothesis of co-adaptive transformation of stromal and epithelial tissues during breast tumoral development and suggest that different types of fibroblasts give rise to different types of myofibroblasts. Discriminant analysis of quantitative molecular variation may be considered for the development of a powerful artificial-intelligence method for cell typing and should be particularly useful when no reliable discrete molecular markers are available.

Indeterminate human immunodeficiency virus type 1 western blot may indicate an abortive infection in some low-risk blood donors.

BACKGROUND: The infectious status of persons with an indeterminate human immunodeficiency virus type 1 (HIV-1) Western blot must be established. STUDY DESIGN AND METHODS: Evaluation of the CD4 and CD8 T-cell subsets and the expression of HIV-1-integrated sequences by Southern blot and polymerase chain reaction were studied in a group of low-risk subjects with an indeterminate Western blot. RESULTS: From a total of 45,000 blood donors and 50 patients with chronic renal failure on hemodialysis who were tested during the period of 1985 through 1990, 50 sera (0.1%) had an indeterminate Western blot. A low CD4:CD8 ratio (0.7-1.2) was detected in 14 of 24 tested subjects, whereas the unfractionated and adherence-enriched cells of 7 (32%) and 5 (23%) of 22 patients, respectively, could be stained with a p24 monoclonal antibody. A transient positive culture was detected in 3 of 20 subjects, but these viral isolates could not be transmitted to CEM-A310 cells. Ultracentrifuged culture supernatants hybridized under high-stringency conditions with genomic gag-pol (4 cases), env (3 cases), and tat (1 case) cDNA fragments of the HXB2 HIV-1 clone. In one case, DNA obtained from adherent but not unfractionated mononuclear cells contained 3.3- and 3.9-kb env- and gag-pol-related HIV-1 sequences, respectively; these sequences were heavier than expected. Polymerase chain reaction analysis for gag and pol but not env sequences was positive in 1 and 2 of 7 cases, respectively. A female patient with a positive viral culture and who was positive for pol in polymerase chain reaction demonstrated a full seroconversion 19 months later. CONCLUSION: The results strongly suggest that, rarely, some low-risk subjects with indeterminate Western blot results might be infected with low-level replicative strains or HIV-related viruses; thus, an exhaustive immunologic and virologic workup is needed for the investigation of these subjects.

Quantitative variation of proto-oncogene and cytokine gene expression in isolated breast fibroblasts.

Transcripts coding for transcription factors (RB, P53, FOS, MYC, MYB, ERBA, REL), growth factors (FGF1, FGF2, INT2, TGFA, TGFB, PDGF, IGF1, IGF2), interleukins, (IL1, IL2, IL3, IL4, IL6, TNF), growth-factor receptors or cytosolic protein kinases (RAF, PIM, FES, MET, SRC, ROS, TRK, KIT, CSFR, IGFR, PDGFR, EGFR, NEU) were quantified in cultured human mammary fibroblasts from normal tissues, benign tumours, carcinomas and post-radiation fibrosis lesions by slot-blot autoradiography and image analysis. The effects of a differentiating agent (cholera toxin) and of a tumour promoter (12-O-tetradecanoyl-phorbol-13-acetate) were also examined. The drugs modulated the levels of the anti-oncogene transcripts (RB, P53) and of ERBA, REL, RAF, MET, ROS, TRK, CSFR, EGFR, NEU, FGF1, INT2, IGF1, IL1, IL2, IL4 and IL6. Apart from this variation, there were multiple differences in gene expression among normal and pathological cells (concerning all but P53, TGFB and interleukin transcripts) and between sub-types defined by the presence of alpha-sm-actin (myofibroblasts) or EDB-fibronectin (RAF, ROS, FES, KIT, IGFR, NEU, INT2, TGFB, PDGF, IGFs, ILs). It appears, therefore, that mammary stroma progress irreversibly along with the epithelium during tumoral development, and that breast cancer is not only a multi-gene but also a multi-tissue phenotype.

Selective interactions between mammary epithelial cells and fibroblasts in co-culture.

Paracrine interactions between breast-cancer cells (MCF7) and stromal fibroblasts were studied in relation to the presence of steroid hormones, using co-cultures in which the 2 populations were separated by a microporous membrane. Densities and DNA-synthesis rates of the co-existing populations were interrelated. Proliferation was, therefore, viewed as the cumulative result of several factors, some of which are non-specific, e.g., are density-dependent, and some are specifically related to the feeders' origin and/or to culture conditions. Specific effects were measured and evaluated by stepwise analysis of covariance. MCF7 stimulated proliferation of fibroblasts differentially. Malignant-tumour fibroblasts were stimulated more than non-pathological ones. The magnitude of these effects was dependent on the presence of steroids. A similar analytical method was used for evaluating differential stromal influences on 4 epithelial phenotypic characters commonly used as prognostic markers. The estrogen-receptor, progesterone-receptor, pS2 and cathepsine-D phenotypes of MCF7, as well as their interrelations, were dependent on the origin of the fibroblasts, i.e., embryonic or adult, normal or tumoral.

Proliferative responses of epithelial cells to 8-bromo-cyclic AMP and to a phorbol ester change during breast pathogenesis.

We have explored the relationship of changes in proliferative responses of human mammary epithelial cells to a phorbol ester (TPA) and to 8-Br-cAMP, which modulate the activities of protein kinases A and C (PKA and PKC), with breast tumour progression. Treatment with TPA had no effect on nontumorigenic cell lines established from human fibrocystic biopsies and apparently normal tissue around a tumour. In contrast, TPA strongly inhibited the proliferation of numerous human tumorigenic breast cell lines. Treatment with 8-Br-cAMP decreased the proliferation of all studied nontumorigenic and tumorigenic cell lines. We have also studied the effect of TPA and 8-Br-cAMP on growth of epithelial cells in short-term culture obtained from surgical human mammary biopsies with different states of breast disease. Both drugs enhanced growth of normal breast cells but had no significant effects on cells from biopsies with benign breast disease. In contrast, all examined cultures from breast cancer biopsies were strongly inhibited by 8-Br-cAMP. Otherwise, TPA had an inhibitory effect only in the case of invasive ductal carcinoma of grade III. Malignant Ha-ras-transformation of nontumorigenic TPA-insensitive breast HBL-100 cells induced an inhibitory effect of TPA. In addition, a TPA-insensitive MCF7 clone was much less tumorigenic in athymic mice than the parental strain shown to be inhibited by TPA. These data suggest that the two intracellular transduction pathways change at different stages of breast pathogenesis. Alterations in the PKA pathway are early events and are probably important to cell immortalization but do not necessarily lead to malignant development. In contrast, changes in PKC pathway are rather later events associated with advanced malignant transformation.

Evaluation of quantitative variation in gene expression.

We investigate the behaviour of the gene-expression rate as a statistical variable using autoradiographic data for 39 transcripts from a heterogeneous set of 80 breast-tissue cultures. Despite standardization, the data distributions of all transcripts showed intervals of normality and intervals of systematic departure from normality which most frequently resulted in a significant skewness and/or kurtosis. Non-normal shapes are attributed to modulation of gene expression. This statistical particularity creates difficulties in the evaluation of differences among specimens. Using classical parametric and non-parametric procedures for normal and non-normal variation, respectively, we demonstrate that large differences in optical density are neither necessary nor sufficient for associating expression rates with biological factors. The transcripts coding for the metalloprotease stromelysin-3 (ST3) and for the receptor to insulin-like growth factors (IGFR) are used as examples and their variation is presented in detail. ST3 expression appeared to be specifically associated with mammary stroma fibroblasts derived from post-radiation fibrosis lesions. IGFR was expressed at higher rates in mammary gland and skin fibroblasts than in mammary epithelial cells and was subject to frequent and strong modulation.

Problems related to the interpretation of autoradiographic data on gene expression using common constitutive transcripts as controls.

The 28S rRNA, a ribosomal RNA, and the ACTB and GAPD mRNAs, coding respectively for beta-actin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), are frequently presented as controls of modulated gene expression. These transcripts were quantified by replicate slot-blot autoradiography and image analysis in mammary epithelial cells and fibroblasts from breast tissues. Each cell-type group comprised strains with different pathological backgrounds, growth rates, antigenic phenotypes and culture histories. The effects of a differentiating agent (cholera toxin) and/or a tumor promoter (12-O-tetradecanoyl-phorbol-13-acetate) were also examined. Despite the impression that visual examination of autoradiographs might create, image analysis suggests that 28S rRNA, ACTB and GAPD are substantially and independently influenced by the above biological factors and by the drugs. Therefore, these transcripts represent specifically regulated cellular activities and may not be taken as alternative indicators of the overall transcription rate or of the amount of material being examined. Instead, such nonspecific variation may be accurately measured and removed from quantitative data using a principal component function. A methodology that allows comparison of expression (or amplification) patterns between genes, between experiments or, even, between laboratories is presented with an example of quantification of transcripts related to cell-growth, differentiation, signaling and cancer.