Non-invasive obstetric anal sphincter injury diagnostics using impedance spectroscopy.

Obstetric anal sphincter injuries are the most common cause of fecal incontinence in women yet remain under-diagnosed. The aim of this study was to assess the suitability of impedance spectroscopy for diagnosing sphincter injuries arising during delivery. This was a prospective single-center study. 22 female patients were included: 10 with symptoms of sphincter dysfunction, in the early postpartum period, and 12 unaffected, in the distant period of more than 2 years after natural delivery. The presence, extent and severity of anal sphincters injury was assessed by measuring the sphincter parameters in physical examination, the degree of sphincter damage in endoanal ultrasound imaging and the sphincters function parameters in anorectal manometry. All measurements were used as references and compared with the outcomes from the impedance spectroscopy models. Impedance spectroscopy showed the highest precision (with mean accuracy of 83.9%) in relation to transanal ultrasonography. 74.1% of its results corresponded to the results of rectal physical examination and 76.7% - to those of anorectal manometry. The method showed the highest accuracy in the assessment of the sphincter's parameters, both anatomically and functionally. New impedance spectroscopy techniques hold promise for detecting obstetric anal sphincter injuries.

Computational Effective Fault Detection by Means of Signature Functions.

The paper presents a computationally effective method for fault detection. A system's responses are measured under healthy and ill conditions. These signals are used to calculate so-called signature functions that create a signal space. The current system's response is projected into this space. The signal location in this space easily allows to determine the fault. No classifier such as a neural network, hidden Markov models, etc. is required. The advantage of this proposed method is its efficiency, as computing projections amount to calculating dot products. Therefore, this method is suitable for real-time embedded systems due to its simplicity and undemanding processing capabilities which permit the use of low-cost hardware and allow rapid implementation. The approach performs well for systems that can be considered linear and stationary. The communication presents an application, whereby an industrial process of moulding is supervised. The machine is composed of forms (dies) whose alignment must be precisely set and maintained during the work. Typically, the process is stopped periodically to manually control the alignment. The applied algorithm allows on-line monitoring of the device by analysing the acceleration signal from a sensor mounted on a die. This enables to detect failures at an early stage thus prolonging the machine's life.

Intrauterine growth retarded piglet as a model for humans--studies on the perinatal development of the gut structure and function.

The overall acceptance of pig models for human biomedical studies is steadily growing. Results of rodent studies are usually confirmed in pigs before extrapolating them to humans. This applies particularly to gastrointestinal and metabolism research due to similarities between pig and human physiology. In this context, intrauterine growth retarded (IUGR) pig neonate can be regarded as a good model for the better understanding of the IUGR syndrome in humans. In pigs, the induction of IUGR syndrome may include maternal diet intervention, dexamethasone treatment or temporary reduction of blood supply. However, in pigs, like in humans, circa 8% of neonates develop IUGR syndrome spontaneously. Studies on the pig model have shown changes in gut structure, namely a reduced thickness of mucosa and muscle layers, and delayed kinetic of disappearance of vacuolated enterocytes were found in IUGR individuals in comparison with healthy ones. Functional changes include reduced dynamic of gut mucosa rebuilding, decreased activities of main brush border enzymes, and changes in the expression of proteins important for carbohydrate, amino acids, lipid, mineral and vitamin metabolism. Moreover, profiles of intestinal hormones are different in IUGR and non-IUGR piglets. It is suggested that supplementation of the mothers during the gestation and/or the IUGR offspring after birth can help in restoring the development of the gastrointestinal tract. The pig provides presumably the optimal animal model for humans to study gastrointestinal tract structure and function development in IUGR syndrome.

Ferroportin expression in haem oxygenase 1-deficient mice.

HO1 (haem oxygenase 1) and Fpn (ferroportin) are key proteins for iron recycling from senescent red blood cells and therefore play a major role in controlling the bioavailability of iron for erythropoiesis. Although important aspects of iron metabolism in HO1-deficient (Hmox1-/-) mice have already been revealed, little is known about the regulation of Fpn expression and its role in HO1 deficiency. In the present study, we characterize the cellular and systemic factors influencing Fpn expression in Hmox1-/- bone marrow-derived macrophages and in the liver and kidney of Hmox1-/- mice. In Hmox1-/- macrophages, Fpn protein was relatively highly expressed under high levels of hepcidin in culture medium. Similarly, despite high hepatic hepcidin expression, Fpn is still detected in Kupffer cells and is also markedly enhanced at the basolateral membrane of the renal tubules of Hmox1-/- mice. Through the activity of highly expressed Fpn, epithelial cells of the renal tubules probably take over the function of impaired system of tissue macrophages in recycling iron accumulated in the kidney. Moreover, although we have found increased expression of FLVCR (feline leukaemia virus subgroup C receptor), a haem exporter, in the kidneys of Hmox1-/- mice, haem level was increased in these organs. Furthermore, we show that iron/haem-mediated toxicity are responsible for renal injury documented in the kidneys of Hmox1-/- mice.

Thermo-sensitive transient receptor potential vanilloid channel-1 regulates intracellular calcium and triggers chromogranin A secretion in pancreatic neuroendocrine BON-1 tumor cells.

Transient receptor potential channels (TRPs) regulate tumor growth via calcium-dependent mechanisms. The (thermosensitive) capsaicin receptor TRPV1 is overexpressed in numerous highly aggressive cancers. TRPV1 has potent antiproliferative activity and is therefore potentially applicable in targeted therapy of malignancies. Recently, we characterized TRPM8 functions in pancreatic neuroendocrine tumors (NETs), however, the role of TRPV1 is unknown. Here, we studied the expression and the role of TRPV1 in regulating intracellular Ca(2+) and chromogranin A (CgA) secretion in pancreatic NET BON-1 cell line and in primary NET cells (prNET). TRPV1 expression was detected by RT-PCR, Western blot and immunofluorescence. Intracellular free Ca(2+) ([Ca(2+)](i)) was measured by fura-2; TRPV1 channel currents by the planar patch-clamp technique. Nonselective cation currents were analyzed by a color-coded plot method and CgA secretion by ELISA. Pancreatic BON-1 cells and NETs express TRPV1. Pharmacological blockade of TRPs by La(3+) (100 µM) or by ruthenium-red (RuR) or by capsazepine (CPZ) (both at 10 µM) suppressed the capsaicin (CAP)- or heat-stimulated increase of [Ca(2+)](i) in NET cells. CAP (20 µM) also increased nonselective cation channel currents in BON-1 cells. Furthermore, CAP (10 µM) stimulated CgA secretion, which was inhibited by CPZ or by RuR (both 10 µM). La(3+) potently reduced both stimulated and the basal CgA secretion. Our study shows for the first time that TRPV1 is expressed in pancreatic NETs. Activation of TRPV1 translates into changes of intracellular Ca(2+), a known mechanism triggering the secretion of CgA. The clinical relevance of TRPV1 activation in NETs requires further investigations.

Altered calcium regulation by thermosensitive transient receptor potential channels in etoposide-resistant WERI-Rb1 retinoblastoma cells.

Differences in transient receptor potential (TRP) and cannabinoid receptor type 1 (CB1) expression levels can serve as prognostic factors for retinoblastoma (RB) tumor progression. We hypothesized in RB tissue that such differences are also indicators of whether or not they are sensitive to etoposide. Accordingly, we compared in malignant etoposide-sensitive and etoposide-resistant WERI-Rb1 cells TRPV1, TRPM8 and TRPA1 subtype and CB1 gene expression pattern levels and accompanying functional activity using quantitative real-time RT-PCR, immunohistochemistry, immunofluorescence microscopy, calcium imaging as well as patch-clamp technology. Gene expression patterns were evaluated in enucleated human RB tissues (n = 4). Both etoposide-resistant and etoposide-sensitive WERI-Rb1 cells expressed all of the aforementioned channels based on responses to known activators and thermal challenges. However, TRPA1 was absent in the etoposide-resistant counterpart. Even though both types of RB cells express TRPV1 as well as TRPM8 and CB1, the capsaicin (50 µM) (CAP)-induced Ca(2+) rise caused by TRPV1 activation was prompt and transient only in etoposide-resistant RB cells (n = 8). In this cell type, the inability of CB1 activation (10 µM WIN) to suppress Ca(2+) responses to CAP (50 µM; n = 4) may be attributable to the absence of TRPA1 gene expression. Therefore, using genetic approaches to upregulate TRPA1 expression could provide a means to induce etoposide sensitivity and suppress RB cell tumorigenesis.

Comparison of thermography and Doppler sonography in the evaluation of the cold immersion test in women with excessive vasospastic reaction.

BACKGROUND: Determining the predisposition to vasospastic reactions in a function test is important at the earliest possible stage of diagnosis. Thermography is an acknowledged procedure for monitoring function tests; however, its availability is limited. The aim of this study was to compare the progression of the cold immersion test in a thermal picture and an US-CD examination with the flow assessment of the small blood vessels of the hand. MATERIAL/METHODS: A group of 16 women declaring high cold tolerance of their hands was compared with a group of 24 women reporting hand complaints when exposed to the cold. The subjects underwent a test in which they immersed their right hand in ice-cold water (0 degrees C). Then images of the temperature distribution in the hand were recorded with a thermovisory camera. At the same time, spectral waveforms were registered in the proper palmar digital artery and in the radial artery at specified time intervals. RESULTS: Data analysis comprised temperature measurements at the level of the nail plate of the middle finger and at the wrist. There were differences between the groups at all the stages of the immersion test (efficient return of temperature to initial values in the reference group, delayed return in subjects with low tolerance to thermal stimuli). Flow resistance analysis using the Doppler method in the studied arteries revealed similar differences between the groups (swift flow normalization and efficient reperfusion in the reference group, higher flow resistance and low reperfusion in subjects with low tolerance to thermal stimuli). CONCLUSIONS: Changes in the parameters of hand warmth during the immersion test assessed by thermography and changes in the flow parameters observed by Doppler sonography demonstrated similar progression, which suggests the equivalence of both methods. Doppler sonography may thus serve as a method of monitoring function tests to establish a predisposition to vasospasm.