Angiotensin-converting enzyme I/D polymorphism and preeclampsia risk: evidence of small-study bias

BACKGROUND: Inappropriate activation of the renin-angiotensin system may play a part in the development of preeclampsia. An insertion/deletion polymorphism within the angiotensin-I converting enzyme gene (ACE-I/D) has shown to be reliably associated with differences in angiotensin-converting enzyme (ACE) activity. However, previous studies of the ACE-I/D variant and preeclampsia have been individually underpowered to detect plausible genotypic risks. METHODS AND FINDINGS: A prospective case-control study was conducted in 1,711 unrelated young pregnant women (665 preeclamptic and 1,046 healthy pregnant controls) recruited from five Colombian cities. Maternal blood was obtained to genotype for the ACE-I/D polymorphism. Crude and adjusted odds ratio (OR) and 95% confidence interval (CI) using logistic regression models were obtained to evaluate the strength of the association between ACE-I/D variant and preeclampsia risk. A meta-analysis was then undertaken of all published studies to February 2006 evaluating the ACE-I/D variant in preeclampsia. An additive model (per-D-allele) revealed a null association between the ACE-I/D variant and preeclampsia risk (crude OR = 0.95 [95% CI, 0.81-1.10]) in the new case-control study. Similar results were obtained after adjusting for confounders (adjusted per-allele OR = 0.90 [95% CI, 0.77-1.06]) and using other genetic models of inheritance. A meta-analysis (2,596 cases and 3,828 controls from 22 studies) showed a per-allele OR of 1.26 (95% CI, 1.07-1.49). An analysis stratified by study size showed an attenuated OR toward the null as study size increased. CONCLUSIONS: It is highly likely that the observed small nominal increase in risk of preeclampsia associated with the ACE D-allele is due to small-study bias, similar to that observed in cardiovascular disease. Reliable assessment of the origins of preeclampsia using a genetic approach may require the establishment of a collaborating consortium to generate a dataset of adequate size

Worldwide distribution of NAT2 diversity: Implications for NAT2 evolutionary history

<p>Abstract</p> <p>Background</p> <p>The N-acetyltransferase 2 (<it>NAT2</it>) gene plays a crucial role in the metabolism of many drugs and xenobiotics. As it represents a likely target of population-specific selection pressures, we fully sequenced the <it>NAT2 </it>coding region in 97 Mandenka individuals from Senegal, and compared these sequences to extant data on other African populations. The Mandenka data were further included in a worldwide dataset composed of 41 published population samples (6,727 individuals) from four continental regions that were adequately genotyped for all common <it>NAT2 </it>variants so as to provide further insights into the worldwide haplotype diversity and population structure at <it>NAT2</it>.</p> <p>Results</p> <p>The sequencing analysis of the <it>NAT2 </it>gene in the Mandenka sample revealed twelve polymorphic sites in the coding exon (two of which are newly identified mutations, C345T and C638T), defining 16 haplotypes. High diversity and no molecular signal of departure from neutrality were observed in this West African sample. On the basis of the worldwide genotyping survey dataset, we found a strong genetic structure differentiating East Asians from both Europeans and sub-Saharan Africans. This pattern could result from region- or population-specific selective pressures acting at this locus, as further suggested in the HapMap data by extremely high values of <it>F</it>_STfor a few SNPs positions in the <it>NAT2 </it>coding exon (T341C, C481T and A803G) in comparison to the empirical distribution of <it>F</it>_STvalues accross the whole 400-kb region of the <it>NAT </it>gene family.</p> <p>Conclusion</p> <p>Patterns of sequence variation at <it>NAT2 </it>are consistent with selective neutrality in all sub-Saharan African populations investigated, whereas the high level of population differentiation between Europeans and East Asians inferred from SNPs could suggest population-specific selective pressures acting at this locus, probably caused by differences in diet or exposure to other environmental signals.</p

Muscle protein metabolism in neonatal alloxan-administered rats: effects of continuous and intermittent swimming training

<p>Abstract</p> <p>Background</p> <p>This study aimed to examine the effects of intermittent and continuous swimming training on muscle protein metabolism in neonatal alloxan-administered rats.</p> <p>Methods</p> <p>Wistar rats were used and divided into six groups: sedentary alloxan (SA), sedentary control (SC), continuous trained alloxan (CA), intermittent trained alloxan (IA), continuous trained control (CC) and intermittent trained control (IC). Alloxan (250 mg/kg body weight) was injected into newborn rats at 6 days of age. The continuous training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 5% of body weight; uninterrupted swimming for 1 h/day, five days a week. The intermittent training protocol consisted of 12 weeks of swimming training in individual cylinder tanks while supporting a load that was 15% of body weight; 30 s of activity interrupted by 30 s of rest for a total of 20 min/day, five days a week.</p> <p>Results</p> <p>At 28 days, the alloxan animals displayed higher glycemia after glucose overload than the control animals. No differences in insulinemia among the groups were detected. At 120 days, no differences in serum albumin and total protein among the groups were observed. Compared to the other groups, DNA concentrations were higher in the alloxan animals that were subjected to continuous training, whereas the DNA/protein ratio was higher in the alloxan animals that were subjected to intermittent training.</p> <p>Conclusion</p> <p>It was concluded that continuous and intermittent training sessions were effective in altering muscle growth by hyperplasia and hypertrophy, respectively, in alloxan-administered animals.</p

H2S biosynthesis and catabolism: new insights from molecular studies

Hydrogen sulfide (H2S) has profound biological effects within living organisms and is now increasingly being considered alongside other gaseous signalling molecules, such as nitric oxide (NO) and carbon monoxide (CO). Conventional use of pharmacological and molecular approaches has spawned a rapidly growing research field that has identified H2S as playing a functional role in cell-signalling and post-translational modifications. Recently, a number of laboratories have reported the use of siRNA methodologies and genetic mouse models to mimic the loss of function of genes involved in the biosynthesis and degradation of H2S within tissues. Studies utilising these systems are revealing new insights into the biology of H2S within the cardiovascular system, inflammatory disease, and in cell signalling. In light of this work, the current review will describe recent advances in H2S research made possible by the use of molecular approaches and genetic mouse models with perturbed capacities to generate or detoxify physiological levels of H2S gas within tissue

Proantocyjanidyny w tkankach kalusowych i w transformowanych korzeniach Rhodiola kirilowii i Rhodiola rosea - oznaczenie za pomocą metody UPLC-MS/MS

Several species of Rhodiola genus (Crassulaceae family) like Rhodiola kirilowii and Rhodiola rosea are used in official or traditional medicine. The aim of this study was to determine qualitative and quantitative content of proanthocyanidins using ultra performance liquid chromatograph connected to a tandem mass spectrometer (UPLC MS/MS method) in the callus tissues and in the transformed roots (infected by Agrobacterium rhizogenes LBA 9402 strain) of R. kirilowii and R. rosea. This validated assay allows to determine the content of five flavan-3-ols: (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG). Our results concerning the material from in vitro cultivation of R. kirilowii and R. rosea indicate that R. rosea callus can be a better source of catechin when compared with other tested materials, especially when the content of (-)-gallate epigallocatechin is taken under consideration (3.429 mg/100 g of dry powdered material). The application of UPLC MS/MS method allowed to determine the content of proanthocyanidins in tested samples with satisfactory precision and can be used in the phytochemical investigations of Rhodiola sp. in vitro cultivated tissues.Niektóre gatunki z rodzaju Rhodiola (rodzina Crassulaceae), jak Rhodiola kirilowii i Rhodiola rosea, są stosowane w medycynie oficjalnej lub ludowej. Celem przedstawionych badań było oznaczenie jakościowe i ilościowe proantocyjanidyn w tkankach kalusowych i w transformowanych (za pomocą szczepu Agrobacterium rhizogenes LBA 9402) korzeniach Rhodiola kirilowii i Rhodiola rosea przy zastosowaniu metodyki wykorzystującej ultrasprawny chromatograf cieczowy sprzężony z tandemowym spektrometrem mas (metoda UPLC MS/MS). Ta zawalidowana metodyka pozwoliła na określenie stężeń pięciu flawan-3-oli: (+)-katechiny, (-)-epikatechiny, (-)-epigalokatechiny, galusanu (-)-epikatechiny (ECG) oraz galusanu (-)-epigalokatechiny (EGCG). Przedstawione w pracy wyniki dotyczące materiału pochodzącego z kultur in vitro R. kirilowii i R. rosea wskazują, że kalus R. rosea jest lepszym źródłem katechin w porównaniu do pozostałych badanych surowców, szczególnie, gdy bierze się pod uwagę zawartość galusanu epigalokatechiny (3.429 mg/100 g suchego sproszkowanego surowca). Zastosowanie opracowanej metodyki z wykorzystaniem ultrasprawnego chromatografu cieczowego sprzężonego z tandemowym spektrometrem mas pozwoliło z zadawalającą precyzją oznaczyć zawartości proantocyjanidyn w analizowanych próbkach. Metoda ta może być stosowana w fitochemicznych badaniach hodowanych in vitro tkanek rodzaju Rhodiola

Involvement of the different extracts from roots of Salvia miltiorrhiza Bunge on acute hypobaric hypoxia-induced cardiovascular effects in rats – preliminary report

The present study was carried out to investigate the protective effects of roots of Salvia miltiorrhiza Bunge on hypobaric hypoxia. Two extracts of S. miltiorrhiza (extract 1: ethanol : water - 50 : 50; extract 2: 96% ethanol) were used. The experiments were performed after 7 consecutive days of administration of the extracts (200 mg/kg b.w., intragastrically) to male Wistar rats. Next, after placing animals for 60 min in the controlled acute hypobaric hypoxia (500 mm Hg) the systolic arterial blood pressure (SAP) in conscious rats, bioelectric heart activity in unconscious rats and analysis of oxidative stress parameters in the blood of rats: malonyldialdehyde (MDA) and lipid peroxidase (LPO) concentration, activity of superoxide dismutase (SOD) or glutathione peroxidase (GPX) were assayed. It was found out that the extract 1 augmented the lowering of SAP shown in hypoxia affected control rats. On the contrary the extract 2 reversed SAP to values obtained in control animals. Moreover, both extracts led to the normalization of hypoxia-induced tachycardia and levels of MDA, LPO and SOD. It seems that the above-mentioned effects are coupled with different active compounds content in the extracts, however more studies are needed to confirm this hypothesis

Proanthocyanidins in Rhodiola kirilowii and Rhodiola rosea callus tissues and transformed roots -determination with UPLC-MS/MS method

S u m m a r y Several species of Rhodiola genus (Crassulaceae family) like Rhodiola kirilowii and Rhodiola rosea are used in official or traditional medicine. The aim of this study was to determine qualitative and quantitative content of proanthocyanidins using ultra performance liquid chromatograph connected to a tandem mass spectrometer (UPLC MS/MS method) in the callus tissues and in the transformed roots (infected by Agrobacterium rhizogenes LBA 9402 strain) of R. kirilowii and R. rosea. This validated assay allows to determine the content of five flavan-3-ols: (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG). Our results concerning the material from in vitro cultivation of R. kirilowii and R. rosea indicate that R. rosea callus can be a better source of catechin when compared with other tested materials, especially when the content of (-)-gallate epigallocatechin is taken under consideration (3.429 mg/100 g of dry powdered material). The application of UPLC MS/MS method allowed to determine the content of proanthocyanidins in tested samples with satisfactory precision and can be used in the phytochemical investigations of Rhodiola sp. in vitro cultivated tissues. Key words: Rhodiola kirilowii, Rhodiola rosea, callus tissues, transformed roots, proanthcyanidins, The mentioned proanthocyanidins (flavan-3-ols), like catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, exhibit antioxidative properties and can protect the organism against harmful effect of free radicals and influenced reactive oxygen forms The in vivo and in vitro cultivation of Rhodiola species are carried out in the Institute of Natural Fibres and Medicinal Plants in Poznan and in the Department of Biology and Pharmaceutical Botany, Warsaw Medical University for several years. In some previously published articles we presented the presence of proanthocyanidins in R. rosea and R. kirilowii roots and callus tissues MATERIAL AND METHODS Plant material Investigations were carried out on five kind of plant material: Rhodiola kirilowii and Rhodiola rosea roots from field cultivation, Rhodiola kirilowii callus tissues, Rhodiola rosea callus tissues and Rhodiola kirilowii transformed roots. Roots from field cultivation The roots of R. kirilowii Callus tissues The callus tissues cultured on solid medium were used in the experiments. Plant material originated from the Garden of Medicinal Plants, Institute of Natural Fibres and Medicinal Plants, Poznań. The callus of R. kirilowii was obtained from the cotyledone of sterile seedling; the callus of R. rosea was obtained from hypocotyl of the sterile seedling. Tissues were cultivated on the modificated Murashige-Skoog (MS) medium Hairy root culture Hairy root culture of Rhodiola kirilowii, established in the Department of Biology and Pharmaceutical Botany, Warsaw Medical University, was derived from a single root developed at the wounded site of the internodal shoot segment, as it was described previously [23], and with the addition of 500 mg/l -1 of L-glutamine. The culture was maintained at 25°C in the dark on a GioGyrotorys Shaker (New Brunswick Scientific Co.) at 122 rpm. The used hairy root line has been investigated for integration of the bacteria DNA into the R. kirilowii genome, as described by Zych et al. using PCR reaction [21]. The content of secondary metabolites was determined in powdered lyophilized tissue of transformed roots. Standard substances The following comparison substances were used in the experiment: (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate, (-)-epigallocatechin gallate (ChromaDex) and D-(-)-salicine (SIGMA). Preparation of test samples: extraction of flavan-3-ols (proanthocyanidins) from dry plant materials The method of flavan-3-ol extraction by P. Mammela roots, an exact amount of ca. 0.75 g of dried powdered (0.315) R. rosea roots, an exact amount of ca. 2.5 g of dried powdered (0.315) R. kirilowii or R. rosea callus tissue and an exact amount of ca. 0.25 g of dried powdered (0.315) R. kirilowii transformed roots were weighed out and placed in a 20 ml volumetric flasks. Methanol in the amount of 15.0 ml of 80% (v/v) was added and the solutions were subjected to ultrasounds for 60 min at a room temperature (20-25ºC). Then the solutions were made up to the mark with the same solvent and filtered on a quantitative filter paper. The filtrates were concentrated to evaporate the methanol up to a volume of about 1/5 in a rotary evaporator in vacuum. The residues were extracted with 4 × 16.0 ml of diethyl ether. The combined ether extracts were dried with anhydrous sodium sulphate and evaporated to dryness in a rotary evaporator in vacuum. The dry residues were dissolved in 4.0 ml of 10% (v/v) methanol and then quantitatively transferred to proper volumetric flasks (in the case of callus tissues 2 ml volumetric flasks were used; in the case of roots or transformed roots 5 ml volumetric flask was used). D-(-)-salicine (IS) in amount of 0.023 ml of 0.5 mg/ml was added to every flasks and the solutions were made up to the mark with 10% (v/v) methanol. The samples were filtered through a membrane filter with a diameter of 0.20 μm

Glucose evaluation trial for remission (GETREM) in type 1 diabetes: a European multicentre study

Objective: Strict metabolic control during the 1st year of type I diabetes is thought to be a key factor fur achieving clinical remission. The aims of this study were two-fold: (i) to evaluate the frequency and duration of spontaneous remission (defined according to the parameters issued by the International Diabetic Immunotherapy Group (IDIG)) in a European population of consecutive recent onset type I diabetes patients (aged 5-35 years), followed-up fur a period of 36 months with a common protocol of intensive insulin therapy and without adjunct immune-intervention; and (ii) to identify the predictive factors for clinical remission. Research design and method: A total of 189 consecutive patients with newly diagnosed type 1 diabetes according to ADA criteria were recruited in participating centres (Belgium, Czech Republic, Estonia, France, Germany, Hungary, Italy, Poland, Romania, Sweden and Turkey) and followed-up for a period of up to 36 months. In all patients, intensive insulin therapy was implemented consisting of three or four injections of regular insulin daily with NPH insulin at bedtime. Adjustment of insulin dose was made according to a common protocol. Various clinical characteristics (age, gender, severity of presentation, etc.), history (presence of diabetic siblings in the family, etc.) and integrated parameters of metabolic control (HbA(1c), blood glucose, the total insulin dose at hospital discharge adjusted for body weight) were collected. Results: Twenty-two patients (11.6%) experienced remission. The median duration of remission was 9.6 months and the range was 31 months. There was a wide variation among centres. Logistic regression analysis focused on the centre as the main variable in achieving remission. Conclusion: Remission was shown to be very heterogeneous between centres depending on 'other factors' such as patient care and family awareness of the disease rather than on 'measurable factors' such as sex, age, HbA(1c) and severity of presentation at diagnosis. Using intensive insulin therapy and optimisation of metabolic control, remission occurred in nearly one out of eight patients. (c) 2004 Elsevier Ireland Ltd. All rights reserved

Porównanie działania antyoksydacyjnego frakcjonowanych wyciągów z siewek i ziela Chelidonium majus L. przy użyciu metod DPPH, ABTS i FRAP

Introduction: Our study is a part of a trend of studies on the antioxidative properties of Chelidonium majus extracts or their fractions suggesting that antioxidant activities may depend on total flavonoid and/or alkaloid contents. Objective: This study focused on the examination of antioxidative activities of full water extract, non-protein fraction and protein fraction of the extract from aerial parts of mature plants and young seedlings. Methods: Total flavonoid and alkaloid contents were evaluated by spectrometric methods. Quantitative determination of chelidonine, coptisine, sanquinarine, berberine was made by HPLCUV. The antioxidative activities were evaluated using (1) 2,2-diphenyl-1-picrylhydrazyl (DPPH), (2) 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and (3) ferric reducing antioxidant power (FRAP) methods. Results: All concentrations of herb extracts exhibited higher antioxidant capacities than extract from seedlings. Two antioxidant tests (DPPH, FRAP) showed that full water extract from herb had the highest antioxidant activity, while its non-protein fraction and protein fraction showed lower antioxidant activity. It was found that the full water extract from herb contained the highest concentrations of flavonoids and alkaloids when compared with other samples. Conclusion: Our findings suggest that chelidonine and coptisine especially could be responsible for the observed changes in the extract antioxidant activity, because these alkaloids were determined in the highest concentration in full water extract from herb. It cannot be also excluded that the observed variables values between extracts and their fractions from herb or from seedlings may also be the result of interactions between flavonoids and other chemical compounds.Wstęp: Nasze badania, będąc częścią trendu badawczego skupiającego się na ocenie aktywności antyoksydacyjnej ekstraktów i ich frakcji z Chelidonium majus wskazują, że działanie przeciwutleniające może być zależne od całkowitej zawartości flawonoidów i/lub alkaloidów. Cel: W badaniu skupiono się na ocenie aktywności antyoksydacyjnej ekstraktów z ziela dojrzałych roślin oraz siewek Ch. majus (pełny ekstrakt wodny, jego frakcja bezbiałkowa i frakcja białkowa). Metody: Całkowita zawartość flawonoidów oraz alkaloidów była oznaczana metodami spektrofotometrycznymi. Ilościową zawartość chelidoniny, koptyzyny, sanquinaryny, berberyny określono metodą HPLC-UV. Aktywność antyoksydacyjną oceniano przy użyciu (1) wolnego rodnika DPPH (2,2-difenylo-1-pikrylohydrazyl), (2) ABTS (kwas 2,2’–azynobis-(3-etylobenzotiazolino-6-sulfonowy)) oraz metodą (3) oznaczania zdolności redukowania jonów żelaza (FRAP). Wyniki: Wszystkie stężenia ekstraktów z ziela wykazywały większą pojemność antyoksydacyjną w porównaniu z ekstraktami z siewek. W dwóch testach antyoksydacyjnych (DPPH, FRAP) wykazano, że pełny ekstrakt wodny z ziela wywierał największą aktywność antyoksydacyjną, natomiast frakcje białkowa i bezbiałkowa tego ekstraktu wykazywały niższą aktywność. Pełny ekstrakt wodny z ziela zawierał najwyższe stężenie flawonoidów i alkaloidów w porównaniu z innymi analizowanymi próbkami. Wnioski: Wyniki badań sugerują, że szczególnie chelidonina i koptyzyna mogą być odpowiedzialne za obserwowane zmiany w aktywności antyoksydacyjnej z uwagi na to, że te alkaloidy oznaczono w największym stężeniu w pełnym ekstrakcie wodnym z ziela. Nie można również wykluczyć, że obserwowane różnice w wartościach badanych zmiennych pomiędzy ekstraktami z ziela Ch. majus i otrzymanymi z siewek mogą wynikać z zachodzenia interakcji flawonoidów z innymi związkami chemicznymi