Active surveillance protocol in prostate cancer in Portugal.

OBJECTIVE: To examine clinical practice patterns in locally managing patients under an active surveillance protocol among Portuguese urologists. INTRODUCTION: Prostate cancer (PCa) is a heterogeneous disease with many prostate adenocarcinomas being indolent and a low probability of ever causing symptoms or death. Active surveillance (AS) is a form of conservative management aimed to reduce over-treatment for low-risk PCa patients. Over the years, experience with AS has grown considerably and is now standard in some countries, however a universal protocol still does not exist. METHODS: Nationwide anonymous e-survey concerning habits and practices on AS among Portuguese urologists, that consisted of twelve questions and was sent electronically to all 368 current members of the Portuguese Urological Association. RESULTS: 56 urologists were surveyed (15.21% answer rate), evenly distributed geographically and allocated according to years of experience as well as number of PCa patients managed monthly. The vast majority of respondents recommends AS to their patients, particularly ISUP grade 1 patients, whose PSA serum level is bellow 20 ng/mL. Observance of AS programs by patients was not in question but concerns exist over psychological morbidity while harboring disease. Majority believed that international guidelines surveillance protocols were adequate and sufficient, but there are some constraints concerning availability of periodic MRIs and re-biopsy needs. CONCLUSIONS: AS seems to be sustained in urologist clinical practice, although patients still lag to adhere and choose for active treatment. AS may not be an easy choice for patients and clinicians due to uncertainty of disease progression, risk of loss to follow-up and repeated biopsies but is also a cause for anxiety, depression, uncertainty and a perception of danger.

Arbuscular mycorrhizal fungi in terms of symbiosis-parasitism continuum.

Arbuscular mycorrhizal fungi are forming the most wide-spread mycorrhizal relationships on Earth. Mycorrhiza contributes to phosphorous acquisition, water absorption and resistance to diseases. The fungus promotes the absorption of nutrients and water from soil, meanwhile the host plant offers photosynthetic assimilates in exchange, like carbohydrates, as energy source. The plant benefits from the contribution of symbiotic partner only when nutrients are in low concentrations in soil and the root system would not be able to absorb sufficiently the minerals. When the help of mycorrhizal fungi is not necessarily needed, the host plant is making an economy of energy, suppressing the development of fungi in the internal radicular space. In this moment, the nature of relationship turns from symbiotic to parasitic, triggering a series of defensive reactions from the plant. Also, there were several cases reported when the presence of arbuscular mycorrhizal fungi negatively influenced the host plant. For example, in adverse environmental conditions, like very high temperatures, instead of determining a higher plant biomass and flowering, the mycorrhiza reduces the growth of the host plant. We conducted a pot experiment with hydroponic culture to examine the effect of arbuscular mycorrhiza on development of French marigold as a host plant. As experimental variants, the phosphorous content in nutrient medium and temperature varied. Plants were artificially infected with arbuscular mycorrhizal fungi using a commercial inoculum containing three fungal species, as following: Glomus intraradices, Glomus etunicatum and Glomus claroideum. Colonization intensity and arbuscular richness were checked using root staining with aniline blue and estimation with the Trouvelot method. To observe the differences between plants from the experimental variants, we examined the number of side shoots, flower buds and fully developed flowers, fresh biomass and total leaf area. Results show that adverse climatic conditions, like temperature shock at the beginning of growing period modified the nature of symbiosis. In this case, the physiological parameters were reduced at colonized plants, while usual, constant growing conditions permitted the normal, efficient and beneficial development of symbiosis.

Integrating medical and genomic data: a successful example for rare diseases.

The recent advances on genomics and proteomics research bring up a significant grow on the information that is publicly available. However, navigating through genetic and bioinformatics databases can be a too complex and unproductive task for a primary care physician. In this paper we present diseasecard, a web portal for rare disease that provides transparently to the user a virtually integration of distributed and heterogeneous information.

Sympathotonic orthostatic hypotension: a report of four cases.

We describe four patients with sympathotonic orthostatic hypotension, a syndrome in which the decrease in blood pressure associated with standing is accompanied by tachycardia. The patients in this series had experienced either a viral infection or rapid weight loss prior to the onset of their orthostatic intolerance. Vasomotor reflexes and norepinephrine production were normal, and analysis of palmar autonomic surface potentials indicated that the sympathetic innervation of the upper extremities was intact. The amplitudes of the plantar autonomic surface potentials, however, were decreased although still within the normal range. The latencies of plantar autonomic surface potentials were slightly prolonged. Although most autonomic function tests are normal in sympathotonic orthostatic hypotension, mild abnormalities in the plantar autonomic surface potentials may indicate a neuropathy that primarily affects low thoracic or lumbar sympathetic neurons.

Effect of the somatostatin analogue SMS-201-995 on the adrenergic response to glucose ingestion in patients with postprandial hypotension.

PURPOSE: The somatostatin analogue SMS-201-995 has recently been introduced as a new therapy for postprandial hypotension in patients with autonomic neuropathy. The present study was performed to determine the effect of SMS-201-995 on the adrenergic response to glucose ingestion in patients with this disorder. PATIENTS AND METHODS: Eleven patients with postprandial hypotension were studied: six with central autonomic dysfunction (multiple system atrophy) and five with peripheral sympathetic dysfunction (progressive autonomic failure). Patients received either a subcutaneous injection of SMS-201-995 or a placebo injection, immediately before administration of a 50-g glucose drink. Each treatment was given on separate, consecutive days in a randomized fashion. RESULTS: Glucose ingestion caused a decrease in blood pressure (from 82 +/- 6 mm Hg to 66 +/- 7 mm Hg, p less than 0.01) and an increase in plasma norepinephrine level (165 +/- 20 pg/mL to 305 +/- 85 pg/mL, p less than 0.01) in five patients with progressive autonomic failure. Administration of SMS-201-995 prevented both the decline in blood pressure and the increase in norepinephrine. By contrast, glucose ingestion elicited no increase in plasma norepinephrine levels despite profound hypotension (average postprandial mean blood pressure, 55 +/- 3 mm Hg) in six patients with multiple system atrophy. Administration of SMS-201-995 prevented postprandial hypotension in these patients, but had no effect on plasma norepinephrine. CONCLUSION: Our data indicate that the pressor effect of SMS-201-995 is independent of the sympathetic nervous system in patients with multiple system atrophy, but may suppress the adrenergic response to glucose ingestion in patients with progressive autonomic failure.

Synthesis and release of gonadotropins and their subunits by long-term organ cultures of human fetal hypophyses.

From weeks 13 to 26 of fetal life human hypophyses disclosed a constant content of radioimmunoassayable FSH. Although present already before this period, LH content increased considerably at week 17, along with the appearance of free beta-LH. In long-term organ culture experiments such early differentiating pituitaries proved to be endowed with autonomous synthesis and release of FSH and of free alpha-subunit, while LH, beta-LH and TSH declined to very low levels within a few weeks. Supplementation of the medium with LH-RH (12 ng/ml) significantly increased FSH synthesis and release but was not sufficient to sustain production of beta-LH and LH. It is suggested that other factors than LH-RH are required for differentiation of beta-LH biosynthesis and thus for production of LH.

The effect of UV irradiation on uracil thin layer measured by optical waveguide lightmode spectroscopy.

The polycrystalline uracil thin-layer dosimeter is a well-established method to monitor the biological effects of the environmental ultraviolet (UV) radiation. It is based on the optical density (OD) decrease of the uracil layer in the UV absorption band due to photodimerization of the crystal caused by UV irradiation. In the present study, we report measurements made with optical waveguide lightmode spectroscopy (OWLS) to characterize the changes in the optogeometrical parameters of the uracil layer caused by an artificial UV source. It is shown that UV irradiation causes a decrease in the refractive index and an increase of the optical anisotropy. The determined kinetic parameters of the UV dose-sensor response curves correlate well with results of OD measurements, but the sensitivity of OWLS is about ten times higher. The results show that OWLS is capable of analyzing the UV response of the uracil layer and opens the way for dosimetrical applications.

Use of uracil thin layer for measuring biologically effective UV dose.

Dimerization of uracil monomers in a polycrystalline state by UV radiation changes the absorption characteristics of a thin layer of the material. The change in optical density, measured by spectrophotometry in the 250-400 nm range, as a function of the exposure time is evaluated in terms of the biologically effective UV dose. A statistical evaluation of a great number of uracil dosimeters irradiated with a TL01 lamp from Philips establishes the possibility of evaluating the biologically effective UV dose using a uracil dosimeter. Nonlinear regression procedures were introduced to correct the absorption spectra for contributions due to light scattering and to determine the optical density values required to calculate the UV dose expressed in HU units. Comparison of cumulative daily doses and long-term monitoring measured by the uracil thin-layer dosimeter and a phage T7 dosimeter are given, which allow the determination of conversion factors between various biological dosimeters under different irradiation conditions.

Assessment of the effects of various UV sources on inactivation and photoproduct induction in phage T7 dosimeter.

The correlation between the biologically effective dose (BED) of a phage T7 biological dosimeter and the induction of cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts ((6-4)PD) in the phage DNA was determined using seven various UV sources. The BED is the inactivation rate of phage T7 expressed in HT7 units. The CPD and (6-4)PD were determined by lesion-specific monoclonal antibodies in an immunodot-blot assay. The various lamps induced these lesions at different rates; the relative induction ratios of CPD to (6-4)PD increased with increasing effective wavelength of irradiation source. The amount of total adducts per phage was compared to the BED of phage T7 dosimeter, representing the average number of UV lesions in phage. For UVC (200-280 nm radiation) and unfiltered TL01 the number of total adducts approximates the reading; however, UV sources having longer effective wavelengths produced fewer CPD and (6-4)PD. A possible explanation is that although the most relevant lesions by UVC are the CPD and (6-4)PD, at longer wavelengths other photoproducts can contribute to the lethal damage of phages. The results emphasize the need to study the biological effects of solar radiation because the lesions responsible for the lethal effect may be different from those produced by various UV sources.

Influence of phage proteins on formation of specific UV DNA photoproducts in phage T7.

Phage T7 can be used as a biological UV dosimeter. Its reading is proportional to the inactivation rate expressed in HT7 units. To understand the influence of phage proteins on the formation of DNA UV photoproducts, cyclobutane pyrimidine dimers (CPD) and (6-4)photoproducts ((6-4)PD) were determined in T7 DNA exposed to UV radiation under different conditions: intraphage T7 DNA, isolated T7 DNA and heated phage. To investigate the effects of various wavelengths, seven different UV sources have been used. The CPD and (6-4)PD were determined by lesion-specific antibodies in an immunodot-blot assay. Both photoproducts were HT7 dose-dependently produced in all three objects by every irradiation source in the biologically relevant UV dose range (1-10 HT7). The CPD to (6-4)PD ratios increased with the increasing effective wavelength of the irradiation source and were similar in intraphage T7 DNA, isolated DNA and heated phage with all irradiation sources. However, a significant decrease in the yield of both photoproducts was detected in isolated T7 DNA and in heated phage compared to intraphage DNA, the decrease was dependent on the irradiation source. Both photoproducts were affected the same way in isolated T7 DNA and heated phage, respectively. The yield of CPD and (6-4)PD was similar in B, C-like and A conformational states of isolated T7 DNA, indicating that the conformational switch in the DNA is not the decisive factor in photoproduct formation. The most likely explanation for modulation of photoproduct frequency in intraphage T7 DNA is that the presence of bound phage proteins induces an alteration in DNA structure that can result in an increased rate of dimerization and (6-4)PD production of adjacent based in intraphage T7 DNA.

Are there two types of diabetic foot ulcers?

Neurological function was determined in diabetic patients with peripheral vascular disease and foot ulcers (n = 13). This was compared to that of diabetic patients without foot ulcers with (n = 23) and without (n = 13) symptoms of neuropathy. Diabetic patients with typical neuropathic ulcers (n = 13) and age-matched healthy controls (n = 20) were also studied. The beat-to-beat variation with deep breathing was 6.1 +/- 1.0 beats/min in those with peripheral vascular disease and foot ulcers, less than 50% of that of diabetic patients without foot ulcers (p < 0.01) or normal controls (p < 0.005). Autonomic surface potentials in the soles were greatly diminished or absent in nearly all the patients with peripheral vascular disease and ulcers. Quantitative sensory testing revealed profound abnormalities in small fiber (heat and cold sensation) and large fiber (vibration sensation) function in diabetic patients with peripheral vascular disease and foot ulcers. Our results document the presence of advanced autonomic and somatosensory neuropathy in nearly all diabetic patients with peripheral vascular disease and foot ulcers.

Phage T7 in biological UV dose measurement.

An experimental method complete with theoretical considerations is presented for the measurement of different biological UV doses. The method is based on the high sensitivity of phage T7 activity to UV light. A precisely determined T7 inactivation action spectrum is presented over a wide optical range (240-514 nm). Using the T7 spectral sensitivity in relation to the minimal erythema dose (MED) and the effective spectral irradiance from solar radiation for the MED, an example is given to determine the MED value based on the measurement of T7 inactivation for a given case. The advantages and applicability of the method are discussed.

Action spectra for photoinduced inactivation of bacteriophage T7 sensitized by 8-methoxypsoralen and angelicin.

The action spectrum (240-300 nm) for photoinactivation of unsensitized phage T7 and the action spectra (310-380 nm) for photoinactivation of phage T7 sensitized with 8-methoxypsoralen (8-MOP) and angelicin were measured by an automated method. For unsensitized phage T7 the action spectrum is in good agreement with the absorption spectrum. For sensitization with angelicin the action spectrum is similar to the absorption spectrum, but for sensitization with 8-MOP the spectra are different. The agreement between the T7 absorption and action spectra in the far-UV region is due to photodamage of DNA, leading to phage inactivation. The similarity in the action and absorption spectra in the near-UV region for sensitization with angelicin seems to be in accordance with the monofunctional photobinding of angelicin to DNA. The action spectrum for sensitization with 8-MOP has a maximum at about 320 nm and this suggests that, in addition to the monoadducts, the biadducts play a role in the inactivation of phage T7. Taking the number of bound furocoumarin molecules into consideration, the quantum efficiencies were estimated. Furocoumarin increases the quantum efficiency in the near-UV region and the values are similar to those obtained in far-UV light without psoralens.

Phage nucleoprotein-psoralen interaction: quantitative characterization of dark and photoreactions.

The irradiation of the phage T7 system containing psoralen as photosensitizer causes many processes, each of them leading to phage inactivation. These processes include the UV-induced photoreactions in the phage nucleic acid, and photoreactions in the nucleic acid sensitized by either psoralen or psoralen photobreakdown products. In addition the intercalation of the psoralen molecule itself in the phage nucleic acid as well as the psoralen photobreakdown products cause phage inactivation. Under appropriate experimental conditions these reactions can be studied and characterized separately. The quantitative characteristics (e.g. inactivation cross-section, action spectra and index for dark genotoxicity) are demonstrated for different linear and angular psoralens. Some theoretical and practical consequences of the results obtained are discussed.

Construction of spectral sensitivity function using polychromatic UV sources.

A procedure is presented for constructing the spectral sensitivity functions of biological dosimeters, using five polychromatic UV sources possessing different emission spectra. Phage T7 and uracil biological dosimeters have been used for measuring the dose rates of the lamps. Their spectral sensitivity functions consisting of two exponential terms have been constructed. The parameters of the spectral sensitivity functions have been determined by comparing the directly measured and calculated dose-rate values. The parameters of the sensitivity function are accepted as correct values when the deviation of the measured and calculated values is a minimum. Based on the deviations between the constructed and the experimentally determined spectral sensitivities with monochromatic sources, the differences between the measured and calculated results are interpreted. The importance of the correct spectral sensitivity data is demonstrated through the effectiveness spectra of a TL 01 lamp for phage T7 killing, uracil dimerization and erythema induction.

The role of the spectral sensitivity curve in the selection of relevant biological dosimeters for solar UV monitoring.

To estimate the risk of enhanced UV-B radiation due to stratospheric ozone depletion, phage T7 and uracil thin-layer biological dosimeters have been developed, which weight the UV irradiance according to induced DNA damage. To study the molecular basis of the biological effects observed after UV irradiation, the spectral sensitivity curves of the two dosimeters and induction of the two major DNA photoproducts, cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts ((6-4)PDs), in phage T7 have been determined for polychromatic UV sources. CPDs and (6-4)PDs are determined by lesion-specific monoclonal antibodies in an immunodotblot assay. Phage T7 and uracil biological dosimeters together with a Robertson-Berger (RB) meter have been used for monitoring environmental radiation from the polar region to the equator. The biologically effective dose (BED) established with the three different dosimeters increases according to the changes in the solar angle and ozone column, but the degree of the change differs significantly. The results can be explained based on the different spectral sensitivities of the dosimeters. A possible method for determining the trend of the increase in the biological risk due to ozone depletion is suggested.

Biological UV dosimeters in the assessment of the biological hazard from environmental radiation.

To determine the impact of environmental UV radiation, biological dosimeters that weight directly the incident UV components of sunlight have been developed, improved and evaluated in the frame of the BIODOS project. Four DNA-based biological dosimeters ((i) phage T7, (ii) uracil thin layer, (iii) spore dosimeter and (iv) DLR-biofilm) have been assessed from the viewpoint of their biological relevance, spectral response and quantification of their biological effectiveness. The biological dosimeters have been validated by comparing their readings with weighted spectroradiometer data, by comparison with other biological doses, as well as with the determined amounts of DNA UV photoproducts. The data presented here demonstrate that the biological dosimeters are potentially reliable field dosimeters for measuring the integrated biologically effective irradiance for DNA damage.

Measurement of proteoglycans, elastase, collagenase and protein in synovial fluid in inflammatory and degenerative arthropathies.

The number of leucocytes and the concentrations of protein, proteoglycans (PG), elastase a1 proteinase inhibitor complexes (E-alpha 1 Pi) and collagenolytic activity were measured in the synovial fluid (SF) of 15 patients with rheumatoid arthritis (RA) and 18 with osteoarthritis (OA). The mean levels of protein, E-alpha 1 Pi and collagenase and the number of leucocytes were higher in RA than in OA SF. However, the mean level of PG was higher of OA SF than in RA. In the latter, they were principally in the form of monomers and fragments while in the former they were in the form of aggregates and monomers. There was a direct relationship between the concentration of E-alpha 1 Pi and either the number of white cells or the concentration of synovial proteins, suggesting that the measurement of E-alpha 1 Pi complexes is a biochemical index of the local inflammatory reaction. There was an inverse correlation between the concentrations of PG and E-alpha 1 Pi which may reflect the effect of degradation in PG of elastase and other enzymes released at the same time. Finally, there was a direct relationship between the concentration of E-alpha 1Pi and collagenase which may be the reflection of a simultaneous release of various enzymes from leucocytes and macrophages.

Stability of nucleic acid under the effect of UV radiation.

Nucleic acids (combined with protein molecules) are essential constituents of the living systems playing an important role in the early evolution of life as well. A specific feature of these molecules has been found and directly confirmed recently: under the influence of short-wavelength UV radiation bipyrimidine photoproducts (cyclobutane dimers and 6-4 bipyrimidines) are induced and the reversion of them can be provoked by the same photons. However, reversion is preferred by the shorter wavelengths. With increasing ratio of the longer wavelength components of the radiation (using artificial UV sources and solar light on the Earth's surface) the impact of the reversible photoproducts in the harmful biological effect decreases and other photoproducts are dominant. Assuming the photoinduced reactions (dimerisation and reversion) are statistical events, during the irradiation the chance for a number of nucleoprotein molecules to survive the radiation damage can be reality. The theoretical and experimental basis of these assumptions will be discussed in the case of bacteriophage T7 nucleoprotein.

Monitoring of environmental UV radiation by biological dosimeters.

As a consequence of the stratospheric ozone layer depletion biological systems can be damaged due to increased UV-B radiation. The aim of biological dosimetry is to establish a quantitative basis for the risk assessment of the biosphere. DNA is the most important target molecule of biological systems having special sensitivity against short wavelength components of the environmental radiation. Biological dosimeters are usually simple organisms, or components of them, modeling the cellular DNA. Phage T7 and polycrystalline uracil biological dosimeters have been developed and used in our laboratory for monitoring the environmental radiation in different radiation conditions (from the polar to equatorial regions). Comparisons with Robertson-Berger (RB) meter data, as well as with model calculation data weighted by the corresponding spectral sensitivities of the dosimeters are presented. Suggestion is given how to determine the trend of the increase in the biological risk due to ozone depletion.