Biomedical subjects

Tomasz Mroczek

Publications and source records attributed to Tomasz Mroczek.

12 recordsLinked to original sources

PubMed2006

Solid-liquid extraction and cation-exchange solid-phase extraction using a mixed-mode polymeric sorbent of Datura and related alkaloids.

Tropane alkaloids solid-liquid extraction methods were developed and comprised ambient pressure ones: extraction with hot solvent, extraction at room temperature, on ultrasonic bath as well as pressurised liquid extraction (PLE) techniques. The highest yields of l-hyoscyamine in methanol PLE method (3 x 5 min, 110 degrees C) and scopolamine extracted with 1% tartaric acid in methanol (15 min, 90 degrees C) were determined. A mixed-mode reversed-phase cation-exchange solid-phase extraction (SPE) procedure was optimised for simultaneous recoveries of L-hyoscyamine, scopolamine, scopolamine-N-oxide from plant extracts as well as quaternary alkaloid representative: scopolamine-N-methyl bromide. First three alkaloids were efficiently eluted (recoveries 80-100%) from an Oasis MCX cartridge with methanol-10% ammonia (3:1, v/v) solution, whereas for the quaternary salt tetrahydrofuran-methanol-25% ammonia (6:1:3, v/v) was used with recoveries 52-6%. HPTLC-densitometric assay on silica gel plates was elaborated at 205 nm without derivatization and included: single development (over a distance 9.5 cm) with acetone-methanol-water-25% ammonia (85:5:5:8, v/v) mobile phase for L-hyoscyamine and scopolamine separation, whereas for scopolamine-N-oxide and scopolamine-N-methyl bromide a second development (to a distance 5.5 cm) with acetonitrile-methanol-85% formic acid (120:5:5, v/v) was applied. Newly elaborated RP-HPLC-diode array detection method was performed on Waters XTerra RP-18 column with gradient of acetonitrile in 15 mM ammonia solution and alkaloids were baseline separated within 20 min. Both chromatographic methods were validated and their quantitative results were compared. Good correlation between HPLC and HPTLC quantitative results was measured (correlation coefficients of mean values were 0.92086 and 0.99995 for L-hyoscyamine and scopolamine, respectively). In the RP-HPLC method, which was from 1.5- up to 7-fold more sensitive than HPTLC, limits of detection (LOD) and limits of quantitation (LOQ, in bracket) were (in ng/microl) as follows: 0.25 (0.82) for L-hyoscyamine, 0.29 (0.97) for scopolamine, 0.13 (0.45) for scopolamine-N-oxide and 0.58 (1.91) for scopolamine-N-methyl bromide. By the use of the optimised chromatographic methods, 14 various samples from the leaves and fruits of Datura sp. were screened for L-hyoscyamine and scopolamine contents and the most promising samples were established.

Alkaloids↗

PubMed2006

Fontan completion in infants.

BACKGROUND: Since the implementation of the Fontan procedure, several clinical factors have been linked to outcome. A study of the outcome after Fontan completion was undertaken with particular attention to the influence of age and cardiac diagnosis. METHODS: Review of all patients (n = 107) undergoing Fontan completion between January 1998 and July 2005 to identify predictors of outcome: early death, prolonged effusions, and prolonged hospital stay. RESULTS: Median age was 13 months (range, 11 to 35) and median weight was 9.4 kgs (6.7 to 15.1). Hypoplastic left heart syndrome was present in 61 patients, and stage I Norwood was the initial palliation in 69. An interim superior cavopulmonary connection was performed in all. A lateral tunnel was used, and a deliberate right to left shunt was created in 99 patients. Mean transpulmonary gradient and pulmonary artery pressure were 5.7 +/- 1.5 mm Hg and 11.6 +/- 2.2 mm Hg, respectively. Median time to extubation was 5 hours (range, 2.5 to 184). Median duration of pleural effusion was 3 days (1 to 58) and was greater or equal to 14 days in 13 patients (12%). Overall mortality was 4.5% (5 of 107). Variables associated with poor outcome included associated noncardiac diagnosis (p < 0.05), elevated transpulmonary gradient (p = 0.03), and pulmonary artery pressure (p < 0.02). Hypoplastic left heart syndrome was the only variable associated with prolonged effusive complications. CONCLUSIONS: Fontan completion can be performed with good results in the first year of life independent of anatomic diagnosis. Significant noncardiac pathology, and a higher pulmonary artery pressure were predictive of worse outcome. Hypoplastic left heart syndrome was associated with prolonged effusions.

Abnormalities, Multiple↗

PubMed2005

Right ventricle-to-pulmonary artery shunt and modified Blalock-Taussig shunt in preparation to hemi-Fontan procedure in children with hypoplastic left heart syndrome.

OBJECTIVE: The advantageous effect of right ventricle-to-pulmonary artery shunt (RV-PA) on the early postoperative hemodynamics in the Norwood procedure for hypoplastic left heart syndrome (HLHS) is well known. Numerous controversies still exist with respect to the late consequences of this new palliation method in preparation for the second stage procedure. METHODS: Between September 1997 and September 2004, a consecutive series of 78 children with HLHS from a single institution underwent the hemi-Fontan procedure: Group 1 (n=27) after Blalock-Taussig shunt (BT), and Group 2 (n=51) after RV-PA. Hemodynamic, echocardiographic and clinical perioperative data were analyzed. RESULTS: There were no significant differences in the age and operative weight (Group 1: 6.9+/-1.04 months, 6.22+/-0.99 kg; Group 2: 6.57+/-1.12 months, 6.36+/-0.86 kg). Children after RV-PA were characterized by a significantly higher preoperative hematocrit value (P=0.014), lower aortic and superior vena cava oxygen blood saturation (P<0.001, P=0.024), severe right ventricle hypertrophy more rarely diagnosed in echocardiography (P<0.004), lower Qp:Qs ratio (P=0.011), larger right (P=0.001) and left (P=0.006) pulmonary artery index and a shorter intensive care unit stay after the hemi-Fontan procedure (P=0.004). CONCLUSIONS: The Norwood procedure with the RV-PA shunt provides satisfactory late hemodynamics and improves the development of the pulmonary arteries. Children with hypoplastic left heart syndrome subjected to this new method of palliation are good candidates for the hemi-Fontan procedure.

Anastomosis, Surgical↗

PubMed2004

On-line structure characterization of pyrrolizidine alkaloids in Onosma stellulatum and Emilia coccinea by liquid chromatography-ion-trap mass spectrometry.

On-line structure characterization of pyrrolizidine alkaloids in two various plant species (Onosma stellulatum W.K., family Boraginaceae and Emilia coccinea Sims., family Compositae) was performed by a newly elaborated RP-HPLC ion trap MS method with atmospheric pressure chemical ionization (APCI) interface. Different PAs (N-oxides, free bases, otonecine alkaloids) isolated were separated on Waters XTerra C18 column using a gradient elution. The combination of a CE-SPE with multiple isolation and fragmentation steps for specific masses in ion trap MS detector enabled fast and sensitive analysis of various types of PAs (N-oxides and free bases). In O. stellulatum, spectra 12 various types of structures (13 different alkaloids) have been determined for the first time: leptanthine-N-oxide, lycopsamine-N-oxide, heliospathuline, lycopsamine, trachelanthamine-N-oxide, dihydroechinatine, leptanthine, heliospathuline-N-oxide, 7-acetylintermedine, uplandicine, echimidine and echimidine-N-oxide. In E. coccinea, the following types of PAs were found: platyphylline-N-oxide, platyphylline (three stereoisomers with the same MS(n) spectrum), ligularidine, neoligularidine, neosenkirkine and also previously reported senkirkine. The method elaborated can be applied in the structural analysis of PAs in newly examined plant materials or food products but further analysis is needed to determine the stereochemistry in details.

Asteraceae↗

PubMed2004

Screening for pyrrolizidine alkaloids in plant materials by electron ionization RP-HPLC-MS with thermabeam interface.

Plant samples from leaves of Cerinthe minor, Cynoglossum clandestinum, Echium tuberculatum (as well roots), Eritrichium rupestre, Lithospermum purpureo-coerulem, Nonnea lutea, Nonnea setosa, Onosma stellulatum and Cynoglossum amabile were screened for toxic pyrrolizidine alkaloids (PAs) with a newly elaborated procedure comprising gradient HPLC with diode array (DAD) and thermabeam electron impact mass spectrometry (EI-MS). Dried plant material was extracted with boiling 1% tartaric acid in methanol for 2 h on an electric basket and crude extracts purified with cation-exchange solid phase extraction (CE-SPE). Purified extracts containing alkaloids were separated on Zorbax SB RP18 stationary phase in gradient of 0.1% formic acid in methanol. The flow rate was 0.25 mL/min and was suitable both for DAD and EI MS detections. Applied gradient procedure permitted quite sufficient separation of PAs in various plant extracts. On the basis of EI MS spectra, toxic PAs with unsaturated 1,2-double bond in the necine moiety were found in all plant materials and in nine of them (excluding only Cynoglossum amabile) for the fi rst time. They included the following types of structures: 9- and 7-viridifloryl-retronecine monoesters, 9-angeloyl-7-viridifloryl-retronecine, 9-angeloyl-retronecine diester, 9-viridifloryl-retronecine saturated ester, 7-angeloyl-9-viridifloryl-retronecine, 7-angeloyl-9-echimidinyl-retronecine, trachelanthamine and others. Selected ion monitoring (SIM) chromatograms at m/z 119, 120 and 136 together with analysis of UV spectra from DAD detector can be applied in rapid screening for toxic PAs in new plant extracts but to obtain detailed structural information (molecular weight and stereochemistry) more expensive hyphenation is required. Consumption of all analysed plants should be avoided as carcinogenic and hepatotoxic properties of the alkaloids detected are expected.

Chromatography, High Pressure Liquid↗

PubMed2004

Right ventricle to pulmonary artery conduit reduces interim mortality after stage 1 Norwood for hypoplastic left heart syndrome.

BACKGROUND: Despite significant improvement in survival after stage 1 Norwood, interim mortality before the second-stage operation remains significant. On the basis of reports of improved circulatory stability associated with the use of a right ventricle to pulmonary artery conduit, the difference between two physiologically different sources of pulmonary blood flow on interim mortality was investigated. METHODS: Data collection of 96 consecutive hospital survivors after stage 1 Norwood surgery was undertaken. The source of pulmonary blood flow was a modified right Blalock-Taussig shunt in 46 (BTS) and a right ventricle to pulmonary artery conduit in 50 patients. The same follow-up protocol was used in both groups. Data analysis was performed to identify variables associated with interim mortality. RESULTS: Analysis of patient-related and procedure-related variables revealed no differences in age, weight, diagnosis, presence of aortic atresia, lowest perioperative pH, duration of cardiopulmonary bypass, circulatory arrest, length of mechanical ventilation, or hospital stay at the time of stage 1 Norwood between groups. Respiratory rate and systolic blood pressure were the only differences detected between groups at the time of discharge. Interim mortality was higher in the Blalock-Taussig shunt group. Statistical analysis identified aortic atresia, a modified Blalock-Taussig shunt, and the presence of perioperative dysrhythmias to be associated with interim mortality. CONCLUSIONS: The use of a right ventricle to pulmonary artery shunt decreases the incidence of interim mortality among hospital survivors after stage 1 Norwood for hypoplastic left heart syndrome. Aortic atresia, the use of a modified Blalock-Taussig shunt, and perioperative dysrhythmias are independently associated with a higher mortality before superior cavopulmonary connection.

Aorta↗

PubMed2004

Anatomical correction of complex forms of transposition of the great arteries in neonates.

OBJECTIVE: The arterial switch operation has become the procedure of choice for the simple transposition of the great arteries (TGA) while in the complex forms of the defect the staged approach is frequently implemented. The aim of this study is to compare groups of patients with simple transposition and children with the complex form of the defect and identify factors affecting early and late outcome. DESIGN: From 1997 to 2003, 135 consecutive neonates with TGA underwent arterial switch operation and simultaneous reparation of all associated defects. Univariate and multivariate analysis of perioperative variables and follow-up data was performed. Patients were divided into two groups. Group I (n=84, 62.2%) included neonates with simple transposition (TGA/IVS), Group II (n=51, 37.8%) included children with complex transposition (TGA/VSD). RESULTS: Overall early mortality was 8.1% and there was one late death (0.7%). One-month, 1-year and 5-year actuarial survival rates were 91.8, 91.1 and 91.1%, respectively. There were no differences in the early and late survival rate between groups. Reintervention rate for right ventricular outflow tract obstruction (RVOTO) was 13.3% (balloon plasty or reoperation). The freedom from reintervention at 1, 3 and 5 years was 98.4, 87.9 and 85.4%, respectively. There were no differences in the need for reintervention between groups. The significant differences between groups concerned: age at operation (p<0.001), associated anomalies (p=0.002) including aortic arch anomalies (p=0.002) and coronary artery anomalies (p=0.02), application of delayed chest closure (p=0.015), and occurrence of sepsis (p=0.032). Risk factors for early death were: left ventricule dysfunction related to age at operation (p=0.016) and resternotomy in intensive care unit (p<0.001). There were no differences between groups concerning these risk factors as far as circulatory arrest time, aorta clamping time, and early and late morbidity. CONCLUSIONS: The arterial switch operation can be the treatment of choice for various forms of TGA with low early and late mortality and morbidity rates. The main cause of early death is still left ventricular dysfunction. Such well-known predictors of poor outcome as presence of ventricular septal defect, coronary artery anomalies and aortic arch anomalies did not affect early and late findings. The presented approach of early simultaneous anatomical correction of TGA and all associated anomalies ensures good condition of children with low necessity for reintervention.

Abnormalities, Multiple↗

PubMed2004

[Pediatric open heart surgery on cardiopulmonary bypass without the use of blood products].

Pediatric open heart surgery is associated with the usage of cardiopulmonary bypass. The circuit is primed with blood products because of risk of excessive hemodilution. The aim of the study was to prove the safety of open heart surgery on cardiopulmonary bypass without the use of blood products in the pediatric group. In this study, 78 patients with atrial septal defect (ASD type II) were enrolled and underwent elective atrial septal defect repair between the years of 1999 and 2003. The group I included 37 children aged from 3 to 16 years (8.79 +/- 4.45) who weighed from 13 to 68.8 kg (29.93 +/- 15.00). In this group, the transfusion of blood products during the surgery and postoperative course was avoided. Blood products were used in a control group (group II 4.1 patients) both during and after surgery. Children from this population ranged in age from 2.5 to 17 years (8.41+/- 4.18) and weighed from 11.5 to 59.7 kg (26.99 +/-12.95). For statistical analysis the t-Student test and U Mann Whitney test were used. The length of stay in the intensive care unit (1.18 +/- 0.47 vs 1.20 +/- 0.61 days) and total hospital stay (8.91 +/- 3.05 vs 10.05 +/- 4.28 days) did not differ statistically between the groups. Values of haematocrit and hemoglobin levels were statistically lower in group I during the postoperative course compared to the control group (intraoperative Hct: 19.43 +/- 4.93 vs 23.37 +/- 4.68%, p < 0.001), but these levels did not correlate with the occurrence of hypoxic, neurologic or coagulation complications. Directly after the surgery, group I had significantly higher platelet and leucocyte counts compared to the control group. There were no differences between the confronted populations in regard to postoperative bleeding (4.61 +/- 2.24 vs 4.76 +/- 1.75 ml/kg). The avoidance of using blood products in pediatric patients during open heart surgery with cardiopulmonary bypass is found to be safe, is not correlated with an increased surgical risk, and does not result in a prolonged hospital stay.

Adolescent↗

PubMed2003

Right ventricle-to-pulmonary artery shunt versus modified Blalock-Taussig shunt in the Norwood procedure for hypoplastic left heart syndrome - influence on early and late haemodynamic status.

OBJECTIVE: The aim of this study was to assess changes in early and late haemodynamic status after the Norwood procedure (NP), caused by the implementation of right ventricle-to-pulmonary artery shunt (RV-PA). METHODS: A consecutive series of 68 children with hypoplastic left heart syndrome underwent NP: Group 1 (n=31) with the application of a modified Blalock-Taussig shunt and Group 2 (n=37) with RV-PA. Haemodynamic data from the early postoperative period (72 h after the operation) and cardiac catheterisation data, as well as blood tests before the hemi-Fontan procedure (HF) were analysed. Univariate (chi(2) test, Mann-Whitney's and Student's t-tests) and multiple regression analysis were carried out. RESULTS: In Group 1, circulatory collapse requiring resuscitation occurred in 15 (48.4%) children, within 72 h after the procedure. The resuscitation was unsuccessful in nine (29%) cases. The operative mortality (30 days) was 35%. In Group 2, two (5%) children died within the early and two (5%) within the late postoperative period. The postoperative course in the remaining children from Group 2 was uneventful. In Group 2 there was a significantly higher mean diastolic pressure after NP (P<0.05). The arterial pulse pressure after NP was significantly lower in Group 2 (P<0.05). Before HF, the application of RV-PA was associated with a lower Qp:Qs ratio (P=0.020), lower aortic pulse pressure (P=0.004) and lower aortic oxygen saturation (P=0.039). CONCLUSIONS: A stable haemodynamic status due to independent coronary perfusion, higher diastolic and lower pulse pressure is the most advantageous effect of RV-PA, resulting in a lower mortality and morbidity after NP. A lower Qp:Qs ratio eliminates the danger of the ventricular volume overload and ensures good conditions for the development of the pulmonary circulation before HF.

Anastomosis, Surgical↗

PubMed2003

The operative outcome in children with supravalvular aortic stenosis.

The authors present their experience in surgical treatment of children with supravalvular aortic stenosis (SAS). A retrospective analysis was carried out on 20 patients operated in the years 1980-1999. The group included 12 boys and 8 girls aged 0.9 to 14.5 years (mean 7.8 +/- 3.4 years). The diagnosis of Williams syndrome in 6 children (30%) was based on the typical face. The mean systolic pressure gradient across the SAS was 84.3 +/- 34.5 mmHg (range from 41 to 168 mmHg). Intraoperative studies allowed to determine that 16 (80%) children had the hourglass type, 2 (10%) tubular type and 2 (10%)--fibromuscular membrane type of stenosis. Sixteen (80%) children had anomalies of the aortic valve and/or coronary arteries, and in 13 (56%) children associated heart or great vessels anomalies were noted. All the patients were operated on using cardiopulmonary bypass and hypothermia. The associated anomalies were corrected simultaneously. There were no early and late deaths. Because of restenosis one child was reoperated. In the follow up the mean systolic pressure gradient between the left ventricle and ascending aorta revealed by echocardiography in 19 (95%) children to be 8 +/- 2 mmHg (range from 0 to 28 mmHg). Eighteen children are now in NYHA class I (New York Heart Association) and develop normally. Supravalvular aortic stenosis is a rare complex anomaly, which, because of life-threatening complications and low operative risk, should be fully repaired as soon as possible.

Adolescent↗

PubMed2002

Simultaneous determination of N-oxides and free bases of pyrrolizidine alkaloids by cation-exchange solid-phase extraction and ion-pair high-performance liquid chromatography.

Cation-exchange solid-phase extraction using LiChrolut SCX (Merck, Darmstadt) cartridges filled with polymeric strong cation-exchanger enabled efficient isolation of both N-oxides and free bases of pyrrolizidine alkaloids (PAs). The recoveries were about 80% for retrorsine-N-oxide, 90% for retrorsine and 100% for senkirkine and were assessed both by TLC-densitometry and ion-pair high-performance liquid chromatography (HPIPC) on Hypersil BDS C8 stationary phase and hexane-l-sulfonic acid as ion-pairing agent. The applied HPIPC gradient procedure was suitable for separation of PAs with various types of structures (N-oxides, free bases, otonecine-PAs). The method limits of detection and quantitation, respectively, ranged from 0.06 ng/microl (senecionine) and 0.2 ng/microl (senkirkine) to 0.1 and 0.35 ng/microl for retrorsine-N-oxide. For each component calibrated by linear regression method, correlation coefficients were higher than 0.9995 (six-point calibration from 4 to 100 microg/ml). The elaborated procedure was used in searching for PAs in plant derived samples from Symphytum sp. (comfrey), Petasites hybridus and Petasites albus (butterbur), Tussilago farfara (coltsfoot), Emilia coccinea (tassel flower) and Doronicum columnae (leopard's bane). For the last three samples macrocyclic PAs (senecionine, senecionine-N-oxide. senkirkine) have been detected for the first time. Details of precision of the analyses are also included.

Cation Exchange Resins↗

PubMed2002

[Early postoperative period in children with hypoplastic left heart syndrome in the comparison of classic and modified Norwood procedures].

INTRODUCTION: The Norwood operation in neonates with hypoplastic left heart syndrome is associated with very high mortality. AIM: To compare early postoperative period in children who underwent classic operation to that in patients who underwent a new modification of the Norwood procedure. METHODS: Evaluation of the early postoperative period (72 h after the operation) in patients who underwent classic operation: Group 1 (31 children) and patients in whom modified Norwood procedure was performed: Group 2 (18 children). The surgical technique of the modified Norwood procedure was presented (right ventricle- to = pulmonary artery shunt and neo-aorta reconstruction by direct anastomosis between aortic arch and main pulmonary artery). RESULTS: In Group 1 in 15 (48.4%) children circulatory collapse occurred, requiring resuscitation, which was unsuccessful in 9 (60%) cases. In Group 2 one child died and early postoperative period of the other was uneventful. The mean circulatory arrest time in deep hypothermia was significantly (p = 0.002) shorter in Group 2 (mean: 33.7 +/- 8.7 min, range 25-53 min) than in Group 2 (mean: 54.1 +/- 6.6 min, range 41-76 min) and cardiopulmonary bypass time was not significantly prolonged (Group 1: mean 70.5 +/- 24.2 min, range 48-167 min; Group 2: mean 62.5 +/- 9.6 min, 39-84 min) (p = 0.765). In Group 2 there was significantly higher diastolic pressure 4, 8, 12, 24 and 36 h after the operation (p < 0.001, p = 0.005, p = 0.037, p = 0.017, p = 0.022, respectively). CONCLUSION: The new modification of the Norwood procedure ensures stable conditions in early postoperative period. We believe that short circulatory arrest time without prolongation of cardiopulmonary bypass time and higher diastolic pressure (the location of the proximal shunt end beneath the valve of the systemic circulation) improves the function of the heart.

Heart Bypass, Left↗