Preeclampsia: from epidemiological observations to molecular mechanisms

Preeclampsia is the main cause of maternal mortality and is associated with a five-fold increase in perinatal mortality in developing countries. In spite of this, the etiology of preeclampsia is unknown. The present article analyzes the contradictory results of the use of calcium supplementation in the prevention of preeclampsia, and tries to give an explanation of these results. The proposal of an integrative model to explain the clinical manifestations of preeclampsia is discussed. In this proposal we suggest that preeclampsia is caused by nutritional, environmental and genetic factors that lead to the creation of an imbalance between the free radicals nitric oxide, superoxide and peroxynitrate in the vascular endothelium. The adequate interpretation of this model would allow us to understand that the best way of preventing preeclampsia is the establishment of an adequate prenatal control system involving adequate antioxidant vitamin and mineral supplementation, adequate diagnosis and early treatment of asymptomatic urinary and vaginal infections. The role of infection in the genesis of preeclampsia needs to be studied in depth because it may involve a fundamental change in the prevention and treatment of preeclampsia.

Comparison of the quantitative competitive and semiquantitative RT-PCR methods for the determination of interferon-gamma mRNA levels in AIDS-free HIV-infected individuals

IFN-gamma mRNA expression was evaluated in nonstimulated peripheral blood mononuclear cells (PBMC) of HIV-infected and seronegative individuals using quantitative competitive and semiquantitative RT-PCR and the sensitivity of these methods was compared. A significant correlation was found between quantitative competitive and semiquantitative RT-PCR in samples of both HIV-seronegative (P = 0.004) and HIV-infected individuals (P = 0.0004). PBMC from HIV-infected individuals presented a remarkable increase of IFN-gamma mRNA expression, as determined by both types of RT-PCR methods. Semiquantitative RT-PCR even without an internal standard is also acceptable for measuring cytokine mRNA expression, but less reliable if small amounts are quantified. Moreover, we found that increased IFN-gammamRNA expression is independent of CD4+ cell count in AIDS-free HIV-infected patients.

Intravenous dipyrone for the acute treatment of episodic tension-type headache: A randomized, placebo-controlled, double-blind study

Acute headaches are responsible for a significant percentage of the case load at primary care units and emergency rooms in Brazil. Dipyrone (metamizol) is easily available in these settings, being the most frequently used drug. We conducted a randomized, placebo-controlled, double-blind study to assess the effect of dipyrone in the acute treatment of episodic tension-type headache. Sixty patients were randomized to receive placebo (intravenous injection of 10 ml saline) or 1 g dipyrone in 10 ml saline. We used seven parameters of analgesic evaluation. The patients receiving dipyrone showed a statistically significant improvement (P<0.05) of pain compared to placebo up to 30 min after drug administration. The therapeutic gain was 30% in 30 min and 40% in 60 min. The number of patients needed to be treated for at least one to have benefit was 3.3 in 30 min and 2.2 in 60 min. There were statistically significant reductions in the recurrence (dipyrone = 25%, placebo = 50%) and use of rescue medication (dipyrone = 20%, placebo = 47.6%) for the dipyrone group. Intravenous dipyrone is an effective drug for the relief of pain in tension-type headache and its use is justified in the emergency room setting.

Plasma free and total carnitine measured in children by tandem mass spectrometry

Free and total carnitine quantification is important as a complementary test for the diagnosis of unusual metabolic diseases, including fatty acid degradation disorders. The present study reports a new method for the quantification of free and total carnitine in dried plasma specimens by isotope dilution electrospray tandem mass spectrometry with sample derivatization. Carnitine is determined by looking for the precursor of ions of m/z = 103 of N-butylester derivative, and the method is validated by comparison with radioenzymatic assay. We obtained an inter- and intra-day assay coefficient of variation of 4.3 and 2.3, respectively. Free and total carnitine was analyzed in 309 dried plasma spot samples from children ranging in age from newborn to 14 years using the new method, which was found to be suitable for calculating reference age-related values for free and total carnitine (less than one month: 19.3 ± 2.4 and 23.5 ± 2.9; one to twelve months: 28.8 ± 10.2 and 35.9 ± 11.4; one to seven years: 30.7 ± 10.3 and 38.1 ± 11.9; seven to 14 years: 33.7 ± 11.6, and 43.1 ± 13.8 µM, respectively). No difference was found between males and females. A significant difference was observed between neonates and the other age groups. We compare our data with reference values in the literature, most of them obtained by radioenzymatic assay. However, this method is laborious and time consuming. The electrospray tandem mass spectrometry method presented here is a reliable, rapid and automated procedure for carnitine quantitation.

Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus)

Blood pressure (BP) profiles were monitored in nine free-ranging sloths (Bradypus variegatus) by coupling one common carotid artery to a BP telemetry transmitter. Animals moved freely in an isolated and temperature-controlled room (24ºC) with 12/12-h artificial light-dark cycles and behaviors were observed during resting, eating and moving. Systolic (SBP) and diastolic (DBP) blood pressures were sampled for 1 min every 15 min for 24 h. BP rhythm over 24 h was analyzed by the cosinor method and the mesor, amplitude, acrophase and percent rhythm were calculated. A total of 764 measurements were made in the light cycle and 721 in the dark cycle. Twenty-four-hour values (mean ± SD) were obtained for SBP (121 ± 22 mmHg), DBP (86 ± 17 mmHg), mean BP (MBP, 98 ± 18 mmHg) and heart rate (73 ± 16 bpm). The SBP, DBP and MBP were significantly higher (unpaired Student t-test) during the light period (125 ± 21, 88 ± 15 and 100 ± 17 mmHg, respectively) than during the dark period (120 ± 21, 85 ± 17 and 97 ± 17 mmHg, respectively) and the acrophase occurred between 16:00 and 17:45 h. This circadian variation is similar to that observed in cats, dogs and marmosets. The BP decreased during "behavioral sleep" (MBP down from 110 ± 19 to 90 ± 19 mmHg at 21:00 to 8:00 h). Both feeding and moving induced an increase in MBP (96 ± 17 to 119 ± 17 mmHg at 17:00 h and 97 ± 19 to 105 ± 12 mmHg at 15:00 h, respectively). The results show that conscious sloths present biphasic circadian fluctuations in BP levels, which are higher during the light period and are mainly synchronized with feeding.

Female pelvic floor disorders – outcome after mesh-augmented procedures and studies on vaginal connective tissue

Pelvic floor disorders, such as urinary incontinence (UI) and pelvic organ prolapse (POP), are common disorders in women. Because of the prolonged life expectancy the prevalence of UI and POP and the probability of ending up in surgery are increasing. However, the pathophysiology behind these disorders is still unsolved. The aim of this thesis is to study possible alterations in the connective tissue in the vaginal wall in patients with and without POP. The long-term outcome and complications of mid-urethral slings (MUS) and mesh-augmented POP surgery were studied in heterogenic patient populations. More elastin and a slight increase in immunostaining of type III and V collagens in tissue samples were obtained from patients with POP compared to controls in whom type I collagen was more prominent. The studies assessing the mesh-augmented procedures revealed good efficacy and high patient satisfaction after a long-term follow-up. Patients operated on because of mixed incontinence and with BMI >30 kg/m² reported significantly more urinary symptoms and a lower quality of life than the patients operated on because of stress urinary incontinence and the ones with BMI ≤30 kg/m². The objective outcome was equal between the groups. Mesh exposure through vaginal mucosa occurred in 23 % of the patients after POP surgery, most of these being asymptomatic. There are alterations in connective tissues in patients with POP. Mid-urethral sling procedures produced good long-term cure rates and patient satisfaction. As to the prolapse surgery, in spite of relatively high exposure rate, mesh-augmented procedure proved to be safe and effective method for the correction of POP.

Quantification of fecal estradiol and progesterone metabolites in Syrian hamsters (Mesocricetus auratus)

Alternative methods to the utilization of laboratory animal blood and its by-products are particularly attractive, especially regarding hamsters due to their small size and difficulties in obtaining serial blood samples. Steroid hormone metabolite quantification in feces, widely used in studies of free-ranging or intractable animals, is a non-invasive, non-stressor, economical, and animal saving technique which allows longitudinal studies by permitting frequent sampling of the same individual. The present study was undertaken to determine the suitability of this method for laboratory animals. Estradiol and progesterone metabolites were quantified by radioimmunoassay in feces of intact, sexually mature female Syrian hamsters during the estrous cycle (control) and in feces of superovulated females. Metabolites were extracted by fecal dilution in ethanol and quantified by solid phase radioimmunoassay. Median estrogen and progesterone concentrations were 9.703 and 180.74 ng/g feces in the control group, respectively. Peaks of estrogen (22.44 ± 4.54 ng/g feces) and progesterone (655.95 ± 129.93 ng/g feces) mean fecal concentrations respectively occurred 12 h before and immediately after ovulation, which is easily detected in this species by observation of a characteristic vaginal postovulatory discharge. Median estrogen and progesterone concentrations (28.159 and 586.57 ng/g feces, respectively) were significantly higher in superovulated animal feces (P < 0.0001). The present study demonstrated that it is possible to monitor ovarian activity in Syrian hamsters non-invasively by measuring fecal estradiol and progesterone metabolites. This technique appears to be a quite encouraging method for the development of new endocrinologic studies on laboratory animals.

Effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and on atherogenesis in apolipoprotein E knock-out mice

Elevated blood cholesterol is an important risk factor associated with atherosclerosis and coronary heart disease. Several studies have reported a decrease in serum cholesterol during the consumption of large doses of fermented dairy products or lactobacillus strains. The proposed mechanism for this effect is the removal or assimilation of intestinal cholesterol by the bacteria, reducing cholesterol absorption. Although this effect was demonstrated in vitro, its relevance in vivo is still controversial. Furthermore, few studies have investigated the role of lactobacilli in atherogenesis. The aim of the present study was to determine the effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and the possible hypocholesterolemic and antiatherogenic action of these bacteria using atherosclerosis-prone apolipoprotein E (apo E) knock-out (KO) mice. For this purpose, Swiss/NIH germ-free mice were monoassociated with L. delbrueckii and fed a hypercholesterolemic diet for four weeks. In addition, apo E KO mice were fed a normal chow diet and treated with L. delbrueckii for 6 weeks. There was a reduction in cholesterol excretion in germ-free mice, which was not associated with changes in blood or liver cholesterol concentration. In apo E KO mice, no effect of L. delbrueckii was detected in blood, liver or fecal cholesterol. The atherosclerotic lesion in the aorta was also similar in mice receiving or not these bacteria. In conclusion, these results suggest that, although L. delbrueckii treatment was able to reduce cholesterol excretion in germ-free mice, no hypocholesterolemic or antiatherogenic effect was observed in apo E KO mice.

Modelling the super-equilibria in thermal biomass conversion : applications and limitations of the constrained free energy method

Bioenergi ses som en viktig del av det nu- och framtida sortimentet av inhemsk energi. Svartlut, bark och skogsavfall täcker mer än en femtedel av den inhemska energianvändningen. Produktionsanläggningar kan fungera ofullständigt och en mängd gas-, partikelutsläpp och tjära produceras samtidigt och kan leda till beläggningsbildning och korrosion. Orsaken till dessa problem är ofta obalans i processen: vissa föreningar anrikas i processen och superjämviktstillstånd är bildas. I denna doktorsavhandling presenteras en ny beräkningsmetod, med vilken man kan beskriva superjämviktstillståndet, de viktigaste kemiska reaktionerna, processens värmeproduktion och tillståndsstorheter samtidigt. Beräkningsmetoden grundar sig på en unik frienergimetod med bivillkor som har utvecklats vid VTT. Den här så kallade CFE-metoden har tidigare utnyttjats i pappers-, metall- och kemiindustrin. Applikationer för bioenergi, vilka är demonstrerade i doktorsavhandlingen, är ett nytt användingsområde för metoden. Studien visade att beräkningsmetoden är väl lämpad för högtemperaturenergiprocesser. Superjämviktstillstånden kan uppstå i dessa processer och det kemiska systemet kan definieras med några bivillkor. Typiska tillämpningar är förbränning av biomassa och svartlut, förgasning av biomassa och uppkomsten av kväveoxider. Också olika sätt att definiera superjämviktstillstånd presenterades i doktorsavhandlingen: empiriska konstanter, empiriska hastighetsuttryck eller reaktionsmekanismer kan användas. Resultaten av doktorsavhandlingen kan utnyttjas i framtiden i processplaneringen och i undersökning av nya tekniska lösningar för förgasning, förbränningsteknik och biobränslen. Den presenterade metoden är ett bra alternativ till de traditionella mekanistiska och fenomenmodeller och kombinerar de bästa delarna av både. --------------------------------------------------------------- Bioenergia on tärkeä osa nykyistä ja tulevaa kotimaista energiapalettia. Mustalipeä, kuori ja metsätähteet kattavat yli viidenneksen kotimaisesta energian kulutuksesta. Tuotantolaitokset eivät kuitenkaan aina toimi täydellisesti ja niiden prosesseissa syntyy erilaisia kaasu- ja hiukkaspäästöjä, tervoja sekä prosessilaitteita kuluttavia saostumia ja ruostumista. Usein syy näihin ongelmiin on prosessissa esiintyvä epätasapainotila: tietyt yhdisteet rikastuvat prosessissa ja muodostavat supertasapainotiloja. Väitöstyössä kehitettiin uusi laskentamenetelmä, jolla voidaan kuvata nämä supertasapainotilat, tärkeimmät niihin liittyvät kemialliset reaktiot, prosessin lämmöntuotanto ja tilansuureet yhtä aikaa. Laskentamenetelmä perustuu VTT:llä kehitettyyn ainutlaatuiseen rajoitettuun vapaaenergiamenetelmään. Tätä niin kutsuttua CFE-menetelmää on aiemmin sovelluttu onnistuneesti muun muassa paperi-, metalli- ja kemianteollisuudessa. Väitöstyössä esitetyt bioenergiasovellukset ovat uusi sovellusalue menetelmälle. Työ osoitti laskentatavan soveltuvan hyvin korkealämpöisiin energiatekniikan prosesseihin, joissa kemiallista systeemiä rajoittavia tekijöitä oli rajallinen määrä ja siten super-tasapainotila saattoi muodostua prosessin aikana. Tyypillisiä sovelluskohteita ovat biomassan ja mustalipeän poltto, biomassan kaasutus ja typpioksidipäästöt. Työn aikana arvioitiin myös erilaisia tapoja määritellä super-tasapainojen muodostumista rajoittavat tekijät. Rajoitukset voitiin tehdä teollisiin mittauksiin pohjautuen, kokeellisia malleja hyödyntäen tai mekanistiseen reaktiokinetiikkaan perustuen. Tulevaisuudessa väitöstyön tuloksia voidaan hyödyntää prosessisuunnittelussa ja tutkittaessa uusia teknisiä ratkaisuja kaasutus- ja polttotekniikoissa sekä biopolttoaineiden tutkimuksessa. Kehitetty menetelmä tarjoaa hyvän vaihtoehdon perinteisille mekanistisille ja ilmiömalleille yhdistäen näiden parhaita puolia.

An extract of Polygonum multiflorum protects against free radical damage induced by ultraviolet B irradiation of the skin

Over the last decades, the incidence of ultraviolet B (UVB)-related skin problems has been increasing. Damages induced by UVB radiation are related to mutations that occur as a result of direct DNA damage and/or the production of reactive oxygen species. We investigated the anti-oxidant effects of a Polygonum multiflorum thumb extract against skin damage induced by UVB irradiation. Female SKH-1 hairless mice were divided into three groups: control (N = 7), distilled water- (N = 10), and P. multiflorum extract-treated (PM, N = 10) groups. The PM (10 g) was extracted with 100 mL distilled water, cryo-dried and 9.8 g was obtained. The animals received a topical application of 500 µL distilled water or PM extract (1, 2, 4, 8, and 16%, w/v, dissolved in distilled water) for 30 min after UVB irradiation (wavelength 280-320 nm, 300 mJ/cm²; 3 min) of the dorsal kin for 14 days, and skin immunohistochemistry and Cu,Zn-superoxide dismutase (SOD1) activity were determined. SOD1 immunoreactivity, its protein levels and activities in the skin were significantly reduced by 70% in the distilled water-treated group after UVB irradiation compared to control. However, in the PM extract-treated groups, SOD1 immunoreactivity and its protein and activity levels increased in a dose-dependent manner (1-16%, w/v, PM extract) compared to the distilled water-treated group. SOD1 protein levels and activities in the groups treated with 8 and 16%, w/v, PM extract recovered to 80-90% of the control group levels after UVB. These results suggest that PM extract strongly inhibits the destruction of SOD1 by UV radiation and probably contains anti-skin photoaging agents.

Exploratory calcineurin inhibitor-free regimens in living-related kidney transplant recipients

Chronic allograft nephropathy is among the major causes of graft loss even in low-risk kidney transplant recipients and correlates with acute nephrotoxic events during the first year post-transplant. Therefore, calcineurin inhibitor-free regimens may improve patient and graft survival among recipients of living-related kidney transplants. To confirm this hypothesis, we evaluated the efficacy and safety of two calcineurin inhibitor-free regimens in 92 low-risk recipients of one-haplotype living-related kidney transplants. Immunosuppression consisted of tacrolimus, azathioprine and prednisone (group I, GI, N = 38), 2 doses of daclizumab, mycophenolate mofetil (MMF), and prednisone (GII, N = 33) and 2 doses of daclizumab, MMF, sirolimus and prednisone (GIII, N = 21). At 12 months, treatment failure (biopsy-confirmed acute rejection, graft loss or death) was higher in GII compared to GIII and GI (54.5 vs 24.0 vs 13.1%, P < 0.01, respectively). In patients of black ethnicity the incidence of acute rejection was 25 vs 83.3 vs 20% (P = 0.055), respectively. Patient and graft survival was comparable. There were no differences in mean creatinine or calculated creatinine clearance at 12 months. Overall incidence of post-transplant diabetes mellitus (3.3%) and cytomegalovirus disease (4.3%) was similar in all groups. Further development of effective calcineurin inhibitor-free regimens should exclude patients of black ethnicity and may need full-induction therapy, perhaps with depleting agents, and concentration-controlled use of sirolimus and MMF.

Comparison of serum hormone levels of captive and free-living maned wolves Chrysocyon brachyurus

Serum hormone levels were compared between captive and free-living maned wolves and seasonal variations of sex hormones were studied. Blood samples were collected from 16 male and 26 female adult animals from Brazilian zoos, and from 30 male and 24 female free-living adults to determine serum progesterone and testosterone by radioimmunoassay. Serum testosterone concentrations varied (P < 0.05) across seasons for 16 captive males, being higher in autumn (2184.7 ± 355.1 pg/mL) than in summer (1080.7 ± 205.4 pg/mL), winter (1270.1 ± 276.6 pg/mL) and spring (963.9 ± 248.1 pg/mL), although they did not differ between summer, winter and spring. Testosterone concentration of 30 free-living males differed (P < 0.05) between autumn (824.1 ± 512.2 pg/mL), winter (14.4 ± 8.0 pg/mL) and spring (151.9 ± 90.5 pg/mL). Comparison between captive and free-living animals showed no difference in autumn (P > 0.05). Sixteen captive males showed higher testosterone concentration during winter and spring compared with 30 free-living animals (P < 0.05). Progesterone concentration varied among seasons in 26 captive females (P < 0.05), being higher in autumn (15.3 ± 3.1 ng/mL) than in summer (6.6 ± 1.5 ng/mL), winter (5.3 ± 3.1 ng/mL) and spring (4.3 ± 0.7 ng/mL). Progesterone concentration of 24 free-living females varied between autumn (17.1 ± 6.0 ng/mL) and winter (1.7 ± 0.3 ng/mL) (P < 0.05), but we could not obtain data for spring or summer. No difference in progesterone levels was observed between captive and free-living females in autumn and winter.

Lead reduces tension development and the myosin ATPase activity of the rat right ventricular myocardium

Lead (Pb2+) poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g) before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 µM) to the bath. Changes in rate of stimulation (0.1-1.5 Hz), relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM), and the effect of isoproterenol (20 ng/mL) were determined before and after the addition of 100 µM Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz) and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 µM. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 µM Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 µM Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 µM Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.

Effect of a cholesterol-rich diet on the metabolism of the free and esterified cholesterol components of a nanoemulsion that resembles LDL in rabbits

We have shown that the free cholesterol (FC) and the cholesteryl ester (CE) moieties of a nanoemulsion with lipidic structure resembling low-density lipoproteins show distinct metabolic fate in subjects and that this may be related to the presence of dyslipidemia and atherosclerosis. The question was raised whether induction of hyperlipidemia and atherosclerosis in rabbits would affect the metabolic behavior of the two cholesterol forms. Male New Zealand rabbits aged 4-5 months were allocated to a control group (N = 17) fed regular chow and to a 1% cholesterol-fed group (N = 13) during a 2-month period. Subsequently, the nanoemulsion labeled with ³H-FC and 14C-CE was injected intravenously for the determination of plasma kinetics and tissue uptake of the radioactive labels. In controls, FC and CE had similar plasma kinetics (fractional clearance rate, FCR = 0.234 ± 0.056 and 0.170 ± 0.038 h-1, respectively; P = 0.065). In cholesterol-fed rabbits, the clearance of both labels was delayed and, as a remarkable feature, FC-FCR (0.089 ± 0.033 h-1) was considerably greater than CE-FCR (0.046 ± 0.010 h-1; P = 0.026). In the liver, the major nanoemulsion uptake site, uptake of the labels was similar in control animals (FC = 0.2256 ± 0.1475 and CE = 0.2135 ± 0.1580%/g) but in cholesterol-fed animals FC uptake (0.0890 ± 0.0319%/g) was greater than CE uptake (0.0595 ± 0.0207%/g; P < 0.05). Therefore, whereas in controls, FC and CE have similar metabolism, the induction of dyslipidemia and atherosclerosis resulted in dissociation of the two forms of cholesterol.

Cognitive performance of young and elderly subjects on the free word recall memory test: effect of presentation order on recall order

The influence of aging on memory has been extensively studied, but the importance of short-term memory and recall sequence has not. The objective of the current study was to examine the recall order of words presented on lists and to determine if age affects recall sequence. Physically and psychologically healthy male subjects were divided into two groups according to age, i.e., 23 young subjects (20 to 30 years) and 50 elderly subjects (60 to 70 years) submitted to the Wechsler Adult Intelligence Scale-Revised and the free word recall test. The order of word presentation significantly affected the 3rd and 4th words recalled (P < 0.01; F = 14.6). In addition, there was interaction between the presentation order and the type of list presented (P < 0.05; F = 9.7). Also, both groups recalled the last words presented from each list (words 13-15) significantly more times 3rd and 4th than words presented in all remaining positions (P < 0.01). The order of word presentation also significantly affected the 5th and 6th words recalled (P = 0.05; F = 7.5) and there was a significant interaction between the order of presentation and the type of list presented (P < 0.01; F = 20.8). The more developed the cognitive functions, resulting mainly from formal education, the greater the cognitive reserve, helping to minimize the effects of aging on the long-term memory (episodic declarative).