Exercise during the first trimester of pregnancy and prevention of gestational diabetes review

Ο διαβήτης κύησης ή ΣΔΚ είναι μια από της πιό συχνές επιπλοκές στην διάρκεια της κύησης και συνδέεται με σοβαρά αποτελέσματα τόσο για την μητέρα όσο και για το νεογνό. Η επίπτωση ποικίλει παγκοσμίως από 9% στην Αφρική, 12,6% στην Βόρεια Αμερική και 21% στην Ασία. Παρ'όλους τους υψηλούς αριθμούς, υπάρχει ακόμα διαφωνία γύρω από την διάγνωση και την θεραπεία του ΣΔΚ και ελλειπή δεδομένα για την πρόληψη του. Η πρόληψη πρώτης γραμμής που χρησιμοποιείται είναι η άσκηση μαζί με διατροφικές αλλαγές. Παρά ταύτα το αν η άσκηση έχει επίδραση για την πρόληψη του σακχαρώδους διαβήτη δεν είναι σαφές λόγω των λίγων τυχαιοποιημένων μελετών, που αναδεικνύουν ασαφή συμπεράσματα. Σε αυτή την εργασία θα αναλυθεί η άσκηση στο πρώτο τρίμηνο της κύησης ως μέθοδος πρόληψης του ΣΔΚ ,τόσο σε γυναίκες με υψηλή προδιάθεση, όσο και με χαμηλή προδιάθεση για ανάπτυξη ΣΔΚ. Για να επιτευχθεί αυτό συνδιάστηκαν δεδομένα απο δημοσιευμένες τυχαιοποιημένες μελέτες των τελευταίων 10 χρόνων. Μετά από επιλογή ,καταλήξαμε σε 6 τυχαιοποιημένες μελέτες και συλλεχθηκέ πληροφορία που μας οδήγησε στο συμπέρασμα ότι η άσκηση στο πρώτο τρίμηνο της κύησης μπορεί να συμβάλλει ως μέθοδος πρόληψης του ΣΔΚ. Υπάρχουν ακόμα πολλές παράμετροι που πρέπει να ερευνηθούν προκειμένου να προσδιοριστεί ένα συγκεκριμένο ποσοστό με το οποίο η άσκηση στο πρώτο τρίμηνο μειώνει την επίπτωση του ΣΔΚ, για το λόγο αυτό περισσότερες τυχαιοποιημένες μελέτες πρέπει να γίνουν στο μέλλον.Gestational diabetes mellitus or GDM is one of the most common complications during pregnancy and it is associated with severe outcomes for both the mother and the newborn. Its prevalence varies globally ranging from 9% in Africa, 12.6% in North America and 21% in Asia. Despite those high numbers, there is still debate around the diagnosis and treatment of GDM and still not enough data concerning its prevention. The first line prevention methods used currently are exercise combined with dietary alterations. However, whether exercise is effective for the prevention of GDM is not clear because the few randomized controlled trials (RCTs) investigating this issue show conflicting results. In this review we will analyze only the exercise during the first trimester as a method of prevention of GDM in both women with high risk of GDM and women with low risk of GDM. In order to do that we combined data already published in Randomized Control Articles during the last 10 years. After a filter method we ended up with 6 RCTs and collected information that led us to the conclusion that exercise in the first trimester can work as a prevention method for GDM. There are still many variables we have to manage in order to determine a specific percentage in which exercise in the first trimester reduces GDM, therefore more controlled and supervised research must be done in the future

Direct determination of kanamycin in raw materials, veterinary formulation and culture media using a novel liquid chromatography-evaporative light scattering method

A novel method for the direct determination of kanamycin A and its minor component kanamycin B was developed and validated based on reversed phase liquid chromatography with evaporative light scattering detector (ELSD). ELSD response to kanamycins was found to be enhanced by: (a) decrease of peak width and asymmetry (obtained by controlling the mobile phase acidity or ratio of organic solvent to water), (b) use of ion-pairing acidic reagents of increased molecular mass, and (c) increase of mobile phase volatility. Utilizing an Spherisorb ODS-2 C18 column, the selected optimized mobile phase was water-acetonitrile (60:40, v/v), containing 11.6 mM heptafluorobutyric acid (isocratic elution with flow rate of 1.0 ml min-1). Kanamycin A was eluted at 3.9 min and kanamycin B at 5.0 min with a resolution of 2.7. Logarithmic calibration curves were obtained from 0.6 to 28 μg ml -1 (r > 0.9998) for kanamycin A and 4-36 μg ml-1 (r > 0.9994) for kanamycin B, with a LOD equal to 0.20 and 1.4 μg ml -1, respectively. In kanamycin acid sulfate pharmaceutical raw materials, the simultaneous determination of sulfate (tR = 2.1 min, LOD = 2.3 μg ml-1, %R.S.D. = 1.7, r > 0.9998) and kanamycins was feasible. No significant difference (t-test) was found between the results of the developed LC-ELSD method and those of reference methods, while recovery from kanamycin B spiked samples ranged from 95 to 105%. The developed method was also applied with very good accuracy for the determination of kanamycin A in veterinary formulation (%recovery 95-103, %R.S.D. < 1.4, n = 3) and for the determination of kanamycins A and B in bacteria culture media (%recovery 102 and 99, respectively). © 2004 Elsevier B.V. All rights reserved

Development and validation of a novel LC/ELSD method for the quantitation of gentamicin sulfate components in pharmaceuticals

The equivalent response of evaporative light scattering detector (ELSD) for compounds of similar structure is exploited to develop an LC/ELSD method for the simultaneous quantitation of the four main components of gentamicin sulfate, using as external standard the one main component kanamycin. A C18 column was used along with a mobile phase consisting of H2O (containing 35.4 μg/ml of trichloroacetic acid and 0.89 μl/ml of trifluoroacetic acid)-methanol-acetonitrile (990:5:5, v/v/v), in an isocratic mode at 1.1 ml/min. Parameters of ELSD were 50°C for evaporation temperature and 3.0 bar for pressure of carrier gas (N2). A logarithmic calibration curve was obtained for sulfate (tR = 1.9 min) from 4.2 to 150 μg/ml (r > 0.994) with a precision of 0.18%R.S.D. Kanamycin and the four gentamicin components (C1a, C2, C2a and C1) were eluted at 3.2, 4.6, 5.9, 7.1 and 8.7 min, respectively, with good resolution (Rs > 1.5). Logarithmic calibration curve was obtained for each component (r > 0.99) with statistically equal slopes varying from 2.457 to 2.558. The mass range of total gentamycin was 35-240 μg/ml. The proposed method was applied for the determination of gentamicin components and sulfate in raw materials and pharmaceutical formulations (injection, drops and cream) without any pretreatment except cream, for which liquid-liquid extraction was required. Recovery from standard addition experiments in commercial formulations was 99-100% regarding total gentamicin and 89-108% regarding individual components, with a precision (%RSD, n = 4) 0.7-5.8%. © 2004 Elsevier B.V. All rights reserved

Ion chromatographic behaviour and determination of perbromates

Ion chromatographic behaviour of perbromates in aqueous solutions was studied, using ion suppressed conductimetric detection (Dionex DX-100 ion chromatograph with ASRS-I suppressor). Various eluents (sodium hydroxide, carbonate and phenate solutions) were examined using the AS-14 4 mm×250 mm anion-exchange column and an optimization study concerning pH and total eluate concentration of mobile phase was carried out. Phenate buffer (20.0 mM, pH 11.0) at 1.18 ml/min flow rate, gave the best results. Calibration curve was linear in the range of 1.5-200 ppm, with a limit of detection of 0.46 ppm and R.S.D. 1.8% (100 ppm standard). Perbromates were separated with good resolution from potentially interfering anions (bromides, bromates, iodides, perchlorates). Selectivity coefficients were determined for perbromates, perchlorates and iodides, from linear plots of retention volume versus the reciprocal of eluent concentration. The new method was used to monitor the perbromate reactions with lactic acid, iodide and citric acid in the absence and presence of Fe(II) acting as an inducer. Furthermore, it was confirmed the inability of various common strong oxidative media to oxidize bromate to perbromate. © 2004 Elsevier B.V. All rights reserved

Development and validation of a novel HPLC/ELSD method for the direct determination of tobramycin in pharmaceuticals, plasma, and urine

A novel method for the direct determination of the aminoglycoside tobramycin was developed and validated based on reversed-phase high-performance liquid chromatography (RP-HPLC) with evaporative light scattering detector (ELSD). Using a Waters ODS-2 C18 Spherisorb column with an evaporation temperature of 45°C and nitrogen pressure of 3.5 bar, the selected mobile phase consisted of water/acetonitrile 55:45 containing 1.5 mL L-1 HFBA (11.6 mM) in an isocratic mode at a rate of 1.0 mL min-1. Tobramycin's retention time was 4.3 min with an asymmetry factor of 1.7. A logarithmic calibration curve was obtained from 1 to 38 μg mL-1 (r > 0.9998). LOD was 0.3 μg mL-1; within-day %RSD was 1.0 (n = 3, 4.7 μg mL-1) and between-day %RSD was 1.1 (3 days within a week). The developed method was applied to the determination of tobramycin in a pharmaceutical crude substance and formulations (eye drops and ointments). Dilution experiments revealed the absence of interference from excipients (no constant and proportional errors); recovery from spiked samples was 99-103% with %RSD < 2.2 (n = 3×3). The developed HPLC/ELSD method was also found to be applicable in the determination of tobramycin in human plasma (0.6-12.5 μg mL-1) and urine (1.5-12.5μg mL-1) after solid-phase extraction using carboxylate cartridges followed by solvent evaporation (×2 preconcentration). A mean recovery of 86% for plasma and 91% for urine was obtained. © Springer-Verlag 2004

Enhancement of evaporative light scattering detection in high-performance liquid chromatographic determination of neomycin based on highly volatile mobile phase, high-molecular-mass ion-pairing reagents and controlled peak shape

In the frame of the development of a novel HPLC-ELSD (evaporative light scattering detection) method for the determination of the aminoglycoside antibiotic neomycin sulfate, the influence of mobile phase composition and peak broadening on ELSD response was evaluated. ELSD response was enhanced by: (a) increase of mobile phase volatility (solvents examined: water, acetonitrile, methanol and acetone), (b) increase of molecular mass of ion-pairing species [acidic reagents tested: formic, acetic, trifluoroacetic, trichloroacetic and heptafluorobutyric acid (HFBA)], and (c) decrease of peak width and asymmetry obtained by controlling the concentration of the ion-pairing acidic reagent (HFBA). Utilizing a Waters ODS-2 C 18 Spherisorb column, evaporation temperature of 45°C and nitrogen pressure of 3.5 bar, the optimized mobile phase was water-acetone (50:50), containing 11.6 mM HFBA, in an isocratic mode at a rate of 1.0 ml/min. Neomycin was eluted at 4.9 min, with asymmetry factor 1.3. Logarithmic calibration curve was obtained from 2 to 50 μg/ml (r > 0.9997). Limit of detection (LOD) was 0.6 μg/ml and R.S.D. = 1.7% (n = 3, 3.3 μg/ml). In raw materials, the simultaneous determination of sulfate (LOD = 3 μg/ml, R.S.D. = 1.7%, r > 0.9998) and of minor impurities was feasible. The developed method was also applied for the determination of neomycin in pharmaceutical formulations (powder, aerosol and cream) without any interference from excipients (recovery from spiked samples ranged from 99 to 102%) and a %R.S.D. of <2.1 (n = 3). The HPLC-ELSD method was also found applicable in the determination of neomycin in animal feeds (LOQ = 0.2%) without any interference from the feed matrices. © 2004 Elsevier B.V. All rights reserved

Twenty years of evaporative light scattering detection

Evaporative light scattering detector (ELSD) is a quasi-universal detector for liquid, countercurrent and supercritical fluid chromatography, since it can detect any analyte less volatile than the mobile phase. Operation principle mainly consists of three successive processes: nebulization of the chromatographic effluent; evaporation of the mobile phase; measurement of the scattered light. After 20 years of development, its usage appears significant advantages and potentialities as well as several limitations. In this paper, operation principles, technological innovations, methodological approaches, chemometrics, application areas (pharmaceuticals, foods and beverages, natural products, biological samples and polymers), potentialities and limitations of ELSD are thoroughly reviewed. A bibliography of 83 representative references is given. Copyright © Taylor & Francis LLC

EDTA determination in pharmaceutical formulations and canned foods based on ion chromatography with suppressed conductimetric detection

A novel direct method for the determination of EDTA was developed and validated based on ion chromatography with suppressed conductimetric detection and anion exchange column (Dionex AS-14, 4 mm × 250 mm). Depending on coexisting substances, suitable eluents are 10 mM carbonate buffer/pH 11.0 or 10.5 (tR,EDTA = 5.5 and 9.4 min, respectively), and 120 mM borate buffer/pH 8.5 (tR,EDTA = 16.2 min). For 10 mM carbonate buffer/pH 11.0 and isocratic flow rate of 1.0 ml min-1, a linear calibration curve was obtained from 2.7 to 100 μg ml-1 (r > 0.998), with LOD 0.87 μg ml-1 and %RSD 1.5 (5 μg ml-1, n = 9). Good resolution was achieved from commonly coexisting anions (chloride, metabisulphite, ascorbate and citrate), and other aminopolycarboxylic acids (EGTA, NTA and DTPA). The potential interference of pharmaceutical substances (caffeine, phenytoin, nembutal, tolbutamide, dicumarol, acetylsulphisoxazole and paracetamol) and metal cations (Ca2+, Cu2+ and Fe 3+) was also examined. The ion chromatographic method was applied for the assay of EDTA in contact lens care solutions, synthetic injection drug solutions, canned mushrooms and mayonnaise, with simple treatment and good recovery (range 74-108%). © 2004 Elsevier B.V. All rights reserved

Determination of L-carnitine in food supplement formulations using ion-pair chromatography with indirect conductimetric detection

A novel method for the determination of L-carnitine in food supplement formulations was developed and validated, using ion-pair chromatography with indirect conductimetric detection. The chromatographic method was based on a non-polar (C18) column and an aqueous octanesulfonate (0.64 mM) eluent, acidified with trifluoroacetic acid (5.2 mM). The retention time was 5.4 min and the asymmetry factor 0.65. A linear calibration curve from 10 to 1000 μg/ml (r = 0.99998), with a detection limit of 2.7 μg/ml (25 μl injection volume), a repeatability %RSD of 0.8 (40 μg/ml, n = 5) and reproducibility %RSD of 2.6 were achieved. The proposed method was applied for the determination of carnitine in oral solutions and capsules. No interference from excipients was found and the only pretreatment step required was the appropriate dilution with the mobile phase. Recovery from spiked samples was ranged from 97.7 to 99.7% with a precision (%RSD, n = 3) of 0.01-2.1%. © 2005 Elsevier B.V. All rights reserved

EDTA determination in pharmaceutical formulations and canned foods based on ion chromatography with suppressed conductimetric detection

A novel direct method for the determination of EDTA was developed and validated based on ion chromatography with suppressed conductimetric detection and anion exchange column (Dionex AS-14, 4 mm × 250 mm). Depending on coexisting substances, suitable eluents are 10 mM carbonate buffer/pH 11.0 or 10.5 (tR,EDTA = 5.5 and 9.4 min, respectively), and 120 mM borate buffer/pH 8.5 (tR,EDTA = 16.2 min). For 10 mM carbonate buffer/pH 11.0 and isocratic flow rate of 1.0 ml min-1, a linear calibration curve was obtained from 2.7 to 100 μg ml-1 (r > 0.998), with LOD 0.87 μg ml-1 and %RSD 1.5 (5 μg ml-1, n = 9). Good resolution was achieved from commonly coexisting anions (chloride, metabisulphite, ascorbate and citrate), and other aminopolycarboxylic acids (EGTA, NTA and DTPA). The potential interference of pharmaceutical substances (caffeine, phenytoin, nembutal, tolbutamide, dicumarol, acetylsulphisoxazole and paracetamol) and metal cations (Ca2+, Cu2+ and Fe 3+) was also examined. The ion chromatographic method was applied for the assay of EDTA in contact lens care solutions, synthetic injection drug solutions, canned mushrooms and mayonnaise, with simple treatment and good recovery (range 74-108%). © 2004 Elsevier B.V. All rights reserved