Chiral zwitterionic stationary phases based on Cinchona alkaloids and dipeptides: Application in chiral separation of dipeptides under reversed phase conditions

Chromatographic behavior of novel chiral stationary phases with bonded selectors based on Cinchona alkaloids modified with dipeptides was studied using dipeptides as probe molecules. Buffer-free and salt containing hydro-organic solutions were used as the mobile phases. The selectors exhibit pseudoenantiomeric behavior with respect to the L/D or LL/DD enantiomers and do not behave so with respect to the LD/DL enantiomers. The alkaloid part of the selectors is the driver of enantioselectivity, while the dipeptide substituent plays a modulating role. The quinidine-based selectors demonstrate stronger adsorption affinity and higher enantioselectivity as compared to the quinine-based selectors. The dipeptide analytes containing a glycyl fragment are weaker retained and their enantiomers are worse separated comparing to dipeptides with both units being larger amino acids. Moreover, a phenyl group in the structure of a dipeptide analyte facilitates enantioseparation. The effect of the mobile phase composition on retention depends on the hydrophobicity of an analyte. Hydrophobic dipeptides are better eluted by methanol-rich solvents, hydrophilic dipeptides are better eluted with water-rich solvents, and dipeptides with an intermediate hydrophobicity demonstrate a U-shaped or more complicated dependence of the retention factor on the percentage of methanol. Even a small buffer addition to the mobile phase decreases retention, but the ion-exchange mechanism was not confirmed. The effect of an electrolyte is rather due to the shielding of the charged groups of the selector reducing thereby electrostatic interaction between the selector and analyte. Efficiency of the novel columns is comparable to that of other brush-type chiral columns, the highest achieved number of the theoretical plates per 1 m varying between 30,000 and 40,000.

Chiral recognition without π-π-interactions: Highly efficient chiral strong cation exchangers lacking an aromatic unit in the molecular structure

Current state-of-the-art chiral stationary phases (CSPs) enable chiral resolution of almost any racemic mixture of choice. The exceptions represent ionizable and ionized substances that fail at any attempts to resolve on commercially available CSPs. These compounds, however, can be efficiently separated on chiral ion exchangers. Commercially available Cinchona alkaloids-based chiral weak ion-exchangers are typically used for chiral resolution of organic acids, while zwitterion ion-exchangers are efficient in the resolution of acids, bases, and zwitterions. The latter possess in their structure a cation exchange unit, which alone can serve as a cornerstone of chiral strong cation exchangers facilitating chiral separation of various basic racemic mixtures. Although chiral strong cation exchangers (cSCX) are efficient CSPs, their structural variations have not been thoroughly studied so far. It was assumed that the mechanism of chiral recognition of basic compounds by cSCX is based predominantly on π-π-interactions, hydrogen bonding and steric interactions (CSP I). To verify this assumption, we aimed in our study on the design and synthesis of cSCX first lacking lateral polar substituents on the aromatic unit in the selector's structure (CSP II), and second, to replace the aromatic unit by a cyclohexane ring (CSP III and IV), thereby to omit completely the π-π-interactions. We hypothesized that this structural change should lead to a partial or complete loss of enantiorecognition power of the selectors. Surprisingly, the non-aromatic cSCXs have shown chiral recognition capability comparable to that of previously described chiral cation exchange-type CSPs: from 16 analytes screened, 11 analytes were baseline resolved and 5 partially resolved on CSP I, while non-aromatic CSP III resolved 10 analytes baseline and 6 partially. We discuss the structural motifs of the known cSCX and the novel non-aromatic selectors in a relationship with their chromatographic performance using a set of basic analytes. Moreover, we present a theory of an effective chiral recognition mechanism by two novel non-aromatic cSCXs based on the chromatographic results and quantum mechanical calculations.

Chiral zwitterionic stationary phases based on Cinchona alkaloids and dipeptides - design, synthesis and application in chiral separation

Chiral resolution of polar organic compounds such as amino acids and peptides represents an important chromatographic task due to increasing significance of natural species, which play important signaling and regulatory roles in the living organisms. Despite the number of available chiral stationary phases, this task remains challenging, since not many of the commercially available systems are capable to resolve non-derivatized zwitterionic species. In this study, we present a target-oriented design of a new class of chiral selectors. Pursuing the goal to separate amino acids, and especially short peptides, we have combined Cinchona alkaloids - quinine and quinidine - with three different biogenic dipeptides. We have synthesized six different chiral stationary phases, with selector loading of ∼200 μmol g-1, and tested their chiral recognition capabilities for acidic, basic and zwitterionic analytes using various mobile phases. We have observed that all chiral stationary phases retain the chiral anion exchange capability known for commercially available Cinchona-based columns leading to baseline or partial resolution of six out of ten analytes. The performance in chiral resolution of basic analytes is not optimum due to the weak cation exchange character of the peptidic residue. However, we report on encouraging results in the chiral resolution of short peptides, for which, depending on their structure, we see the chiral resolution of up to three stereoisomers (from four possible) in a preliminary screening.

Synthesis, identification, chiral separation and crystal structure of (3R,4R,7S,8S)-3,4,7,8-tetrachlorodecane and its stereoisomers

Chlorinated paraffins (CPs) are a notoriously known class of compounds that stand amongst the most wide-spread persistent organic pollutants. Therefore, their reliable, repeatable, and reproducible quantitative analysis using well-defined reference standards is of utmost importance. In view of the increasing demand for constitutionally and stereochemically defined CP standards, we have synthesized a stereoisomeric mixture of 3,4,7,8-tetrachlorodecane. One stereoisomer - (3R,4R,7S,8S)-3,4,7,8-tetrachlorodecane was separated from the mixture, and enriched fractions of residual stereoisomers were achieved through crystallisation of the residual mother liquors. The molecular structure of the single isolated stereoisomer was confirmed through single-crystal X-ray crystallographic data. One fraction of 3,4,7,8-tetrachlorodecane stereoisomers was successfully separated on a chiral stationary phase using supercritical fluid chromatography hyphenated to mass spectrometry (column: Chiral ART Amylose-C; mobile phase: CO₂/MeOH (96/4 v/v) with 0.1% diethylamine). The reported separation of stereoisomers is unprecedented in CP analysis so far.

Design of Bis(1,10-phenanthroline) Copper(I)-Based Mechanochromic Indicators

In the growing field of single-molecule mechanochromism, the potential of transition metal complexes is yet to be examined. In this work, we have synthesized a series of [Cu(phen)₂]⁺ complexes: bis-Cu(I)-phenanthroline, bis-Cu(I)-phenanthroline-2-amine, and bis-Cu(I)-phenanthroline-2-acetamide. After that, we characterized the complexes by UV-vis spectroscopy and employed density functional theory (DFT) calculations to investigate the changes in UV-vis upon mechanical pulling via force calculations. The results of our examination of time-dependent (TD)-DFT-calculated UV-vis suggests that the bis-Cu(I)-phenanthroline-2-acetamide complex is predicted to have an observable shift of the metal-to-ligand charge transfer band upon pulling from 0 to 0.6 nN in the visible region. We have demonstrated the ability to synthesize and characterize bis-Cu(I)-phenanthroline-2-acetamide. In addition, the TD-DFT calculations predict an observable shift in the visible region of the UV-vis spectrum. This indicates that transition metal complexes are feasible candidates as mechanophores and are worthy of further exploration as to their potential role in a new subclass of mechanochromic indicators.

Retrospective analysis of necrotizing pneumonia in children between 2015-2019

INTRODUCTION

An increased incidence rate of cases of complicated pneumonia, reaching up to the stage of necrotizing pneumonia was observed at University Hospital Brno in the past period. The aim of this study was to perform a single-center retrospective analysis of patients with acquired inflammatory lung disease requiring surgical treatment, comprising a long-term follow-up group.

METHODS

Patients hospitalized for community-acquired pneumonia and surgically treated in the years 2015-2019 were analyzed. The rates of necessary chest drainages, decortications and lung resections in relation to the whole group and individual years were monitored. Clinical and X-ray examinations were performed one year after hospitalization and the prognosis was determined for individual types of required treatments. The age, gender and etiological agents were also monitored.

RESULTS

A total of 688 patients were included in the study with the incidence rising until 2018 and decreasing slightly in 2019. A statistically significantly higher number of community-acquired pneumonias and complications was recorded between 2017 and 2018 (p.

Myofibroblastic tumor of the esophagus - a case report of long-term follow-up and literature review

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm with intermediate malignant potential. Although most often seen in the lungs, it can occur at multiple anatomical locations, including the gastrointestinal tract. An esophageal lesion is extremely rare, however. IMTs present most commonly in children and young adults. The main therapeutic approach is surgical resection.

CASE REPORT

We report on the follow-up of a case in a 13-year-old boy with IMT in the esophagus. He underwent surgical resection in 2013 and is free of disease to date.

CONCLUSION

Surgical resection is the most preferred therapy. If the resection is complete, the risk of recurrence is low. Nevertheless, every patient should be carefully followed up after the resection.

Combining Segmentation and Edge Detection for Efficient Ore Grain Detection in an Electromagnetic Mill Classification System

This paper presents a machine vision method for detection and classification of copper ore grains. We proposed a new method that combines both seeded regions growing segmentation and edge detection, where region growing is limited only to grain boundaries. First, a 2D Fast Fourier Transform (2DFFT) and Gray-Level Co-occurrence Matrix (GLCM) are calculated to improve the detection results and processing time by eliminating poor quality samples. Next, detection of copper ore grains is performed, based on region growing, improved by the first and second derivatives with a modified Niblack's theory and a threshold selection method. Finally, all the detected grains are characterized by a set of shape features, which are used to classify the grains into separate fractions. The efficiency of the algorithm was evaluated with real copper ore samples of known granularity. The proposed method generates information on different granularity fractions at a time with a number of grain shape features.

[Laparoscopy at the pediatric surgery department for a five-year period]

INTRODUCTION

Laparoscopy in small children was developed only after the adoption and verification of basic principles in adult patients and is mostly concentrated in specialized facilities due to the possible complications and necessity of follow-up specialized anesthesiological and post-operative care. In the 1990s, the Clinic of Paediatric Surgery, Orthopaedics and Traumatology at University Hospital Brno was one of the first in the Czech Republic to begin operating on children laparoscopically. The presented study informs about the development of these minimally invasive methods, the frequency of their use, and the spectrum of patients at the pediatric surgery facility where laparoscopy in children has been systematically developed over many years.

METHODS

Retrospective analysis of children operated upon laparoscopically at the clinic of Paediatric surgery, Orthopaedics and Traumatology of University Hospital Brno over the five-year period from 1 January 2012 to 31 December 2016. A list of surgical procedures was prepared which was then first divided into procedures specific exclusively for children and those common to adult patients surgery. Separately, an overview was prepared of operated patients under 50 kg, which was the boundary criterion defined by the authors for laparoscopy in children as opposed to adults. For all procedures, the frequency of the completed cases performed laparoscopically was precisely ascertained. The source for this data was the hospital system and surgical documentation.

RESULTS

In the evaluated period, a total of 995 laparoscopic procedures were performed, more than half of which (56.8%) were in patients under 50 kg. The majority of those were procedures performed also in adults. The group of surgical operations exclusively specific to children was characterized by low frequencies of the individual procedures.

CONCLUSION

The presented analysis confirms that laparoscopy in children is based on standard procedures common to surgery on adults. These procedures are adopted the most quickly, and they can be disseminated across a large group of surgeons who are then able to perform these routinely on child patients. Surgical procedures exclusively specific for children, on the other hand, are performed less frequently, their adoption is slower, and laparoscopic approach is less common. Therefore, laparoscopy specific to children needs to be performed on a long-term basis, systematically, and within a small group of surgeons. Otherwise, it is better not to perform it at all.Key words: laparoscopy - child frequency.

Silica gel-immobilized multidisciplinary materials applicable in stereoselective organocatalysis and HPLC separation

In this pilot study, we present novel bifunctional silica gel-immobilized materials applicable as heterogeneous organocatalysts and stationary phases in HPLC. The materials provided high stereoselectivity in both batch and continuous flow catalysis of a model Michael addition (cyclohexanone to (E)-β-nitrostyrene). In the batch reaction, the catalysts proved their sustainable catalytic activity over five consecutive recycling experiments. Under continuous flow reaction conditions, the catalytic activity was found to be superior to the batch reaction, and moreover, the same immobilized materials were utilized as stationary phases in HPLC showing very good chemoselective separation of model acidic analytes.

Novel multidisciplinary silica gel-based materials were successfully employed in highly stereoselective Michael addition and as stationary phases in HPLC separation.

Influence of salicylic acid pretreatment on seeds germination and some defence mechanisms of Zea mays plants under copper stress

The study was focused on the influence of salicylic acid (SA) on maize seeds germination and on some physiological and biochemical processes in maize plants growing in the hydroponic culture under copper (Cu) stress. A significant influence of SA pretreatment on the advanced induction of the maize seeds metabolic activity and the level of the endogenous SA in germinated seeds and developing roots have been stated. Although, the ability of maize seeds to uptake SA and accumulate it in the germinated roots was confirmed, the growth inhibition of Cu-stressed maize seedlings was not ameliorated by SA seeds pretreatment. Cu-stressed plants exhibited a decrease in the photosynthetic pigment concentration and the increase in non-photochemical quenching (NPQ) - an indicator of an excess energy in PSII antenna assemblies lost as a heat. The amelioration effect of SA application was found only for carotenoids content which increased in stressed plants. It was also shown that maize roots growing in stress conditions significantly differed in the chemical composition in comparison to the roots of control plants, but the SA pretreatment did not affect these differences. On the other hand, it was found that SA seed pretreatment significantly influenced the ability of stressed plants to accumulate copper in the roots. It was stated that a higher level of exogenous SA application led to a lower accumulation of Cu ions in maize roots. Cu-stressed plants exhibited higher oxidative stress in roots than in leaves which was manifested as an increase in the concentration of hydrogen peroxide due to stress factor application. We observed an increase in catalase (CAT) activity in leaves of Cu-stressed plants which corresponded with a lower H₂O₂ content when compared with roots where the hydrogen peroxide level was higher, and the inhibition of the CAT activity was found. Furthermore, we found that the SA seed pretreatment led to a decrease in the H₂O₂ content in the roots of the Cu-stressed plants, but it did not influence the H₂O₂ level in leaves. The increase in hydrogen peroxide content in the roots of Cu-stressed plants correlated with a higher activity of the MnSODI and MnSODII isoforms. It was found that SA pretreatment caused a decrease in MnSODII activity accompanied by the decrease in H₂O₂ concentration. Achieved results indicated also that the changes in the chemical composition of the root tissue under copper stress constituted protection mechanisms of blocking copper flow into other plant organs. However, it might be assumed that the root tissue remodelling under Cu stress did not only prevent against the Cu ions uptake but also limited the absorption of minerals required for the normal growth leading to the inhibition of the plant development.

Effects of Cd and Zn on physiological and anatomical properties of hydroponically grown Brassica napus plants

Clarifying the connection between metal exposure and anatomical changes represents an important challenge for a better understanding of plant phytoextraction potential. A hydroponic screening experiment was carried out to evaluate the effects of combined interactions of Cd and Zn on mineral uptake (Mg, K, Ca, Na) and on the physiological and anatomical characteristics of Brassica napus L cv. Cadeli, Viking, and Navajo. Plants were exposed to 5 μM Cd (CdCl₂), 10 μM Zn (ZnSO₄), or both Cd + Zn, for 14 days. Cadmium exposure led to a significant reduction in root growth, shoot biomass, and chlorophyll content. After Cd-only and Cd + Zn treatment, primary root tips became thicker and pericycle cells were enlarged compared to the control and Zn-only treatment. No differences between metals were observed under UV excitation, where all treatments showed more intensive autofluorescence connected with lignin/suberin accumulation compared to control conditions. The highest concentrations of Cd and Zn were found in the roots of all tested plants, and translocation factors did not exceed the threshold of 1.0. The root mineral composition was not affected by any treatment. In the shoots, the Mg concentration slightly increased after Cd-only and Cd + Zn treatments, whereas Zn-only treatment caused a sharp decrease in Ca content. Slight increases in K were seen after the addition of Zn. Significantly higher concentrations of Na were induced by Cd- or Zn-only treatment.

Effect of Selected Pyrazine Derivatives on the Production of Phenolics and Rutin in Urtica dioica and Fagopyrum esculentum

The effect of four pyrazine derivatives on the content of phenolic compounds in Urtica dioica L. and rutin in Fagopyrum esculentum Moench was studied. Pyrazine derivatives H1 and H2 were used on U. dioica, and derivatives S1 and S2 on F. esculentum, both separately and in combination with urea. The content of phenolic compounds in the stems of U. dioica after treatment with H2 at a concentration of 10−3 M significantly increased compared with the control and to a lower concentration of the same pyrazine derivative. In the case of S1 and S2 for F. esculentum, rutin content also increased in stems, mainly after treatment together with urea. By contrast, rutin and phenolics contents in the leaves did not change in comparison with controls after application of H1, H2, S1 and S2. Treatment with H1 and H2 in two chosen concentrations resulted in a significant increase in the net photosynthetic rate, transpiration rate and stomatal conductance. A slight increase in the rate of photosynthesis was observed also after application of variants of S1 and S1 with urea. Pyrazine derivatives did not show any effect on either the relative content of chlorophyll or chlorophyll fluorescence. A slight weight reduction of above ground biomass was shown only after application of S1 and S2. Dark necrosis on the edges and center of the leaves was observed in all treated plants after pyrazine application. The results suggest that all the pyrazine derivatives possess herbicidal effects.

Absolute configuration of the antimalarial erythro-mefloquine – vibrational circular dichroism and X-ray diffraction studies of mefloquine and its thiourea derivative

The long-standing discussion of the absolute configuration of erythro-mefloquine is revisited, showcasing the strength of a combination of experimental and calculated vibrational circular dichroism spectroscopy.

Effect of ultrasound on the isoflavonoid production in Genista tinctoria L. suspension cultures

Background:

Application of ultrasound (US) to biotechnology is relatively new but several processes that take place in the presence of cells or enzymes are activated by ultrasonic waves. Genista tinctoria L. (Fabaceae) is rich on various kind of flavonoids, including isoflavones with valuable estrogenic activity.

Objective:

This study verified use of low-energy US elicitor to enhance secondary metabolite production in plant cell cultures.

Materials and Methods:

Suspension cultures of G. tinctoria cells was exposed to low-power US (with fixed frequency 35 kHz and power level 0.1 mW/cm³) for period 1-5 min.

Results:

The US exposure significantly stimulated genistin content (0.8 mg/g DW) after 3 min of US treatment (sampled after 72 h). The highest daidzein level (1.4 mg/g DW) was reached after US irradiation for 5 min and 168 h sampling.

Conclusion:

The achieved results suggest that US can act as a potent abiotic elicitor to induce the defense responses of plant cells and to stimulate secondary metabolite production in plant cell cultures.

Antioxidant Activity and Phenolic Content of Bergenia crassifolia, B. x ornata and B. ciliata

This study focused on a phytochemical analysis of Bergenia crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb., and B. x ornata Stein. and evaluation of their free radical scavenging properties. Arbutin and total tannin contents of the leaves of the Bergenia species were determined during different seasons. The present study also aimed at analyzing, for the first time, environmental influence on concentrations of phenolic metabolites in Bergenia leaves. The highest total tannin content was found in the leaves of B. crassifolia (24.9 – 48.7 mg.g−1 DW) and B. x ornata (36.9 mg.g−1 DW). The highest amount of arbutin was in the leaves of B. x ornata (35.8 – 51.0 mg.g−1 DW) and B. crassifolia (24.6 – 41.7 mg.g−1 DW). Autumn was better than spring for the collection of Bergenia leaves for the highest amount of arbutin ( B. x ornata: 51.0 mg.g−1 DW). Free radical scavenging potential, in DPPH and ABTS assays, of the water leaf extracts revealed that extracts of B. crassifolia and B. x ornata are the most active radical scavengers. Antioxidant activity correlated well with the content of total tannin, especially in the ABTS assay, which suggests an important role for these compounds in antioxidant activity. It was shown that phenolic concentrations in Bergenia leaves are affected by seasonal factors. A significant correlation was found between arbutin and tannin contents and the average humidity.

[Laparoscopic cholecystectomy in children and adolescents]

INTRODUCTION

In the treatment of cholelithiasis in adults, laparoscopic cholecystectomy is the method of first choice. There is plentiful literary evidence of the low complication incidence in this age group, but similar assessment is lacking in the paediatric population. In this work, the authors focus on cholelithiasis in children and the possible use of laparoscopy in the diagnostic - therapeutic scheme.

MATERIAL AND METHODS

The study group consisted of 148 patients operated on by laparoscopic cholecystectomy between 2002 and 2011 at the Department of Paediatric Surgery, Orthopaedics and Traumatology of University Hospital Brno. The first objective of the study was to evaluate the length of surgery; the second one was the occurrence of complications which were divided into intraoperative and postoperative. Intraoperative complications were subdivided into severe and moderate, postoperative complications into early and late. The last objective was to evaluate the benefit (number of complications, treatment outputs) of intraoperative cholangiography for obstructive jaundice before the surgery.

RESULTS

In the above mentioned period, 143 laparoscopic cholecystectomies and five laparoscopic cholecystectomies including splenectomy were performed. The average age of the patients was 13.9 years; the average length of laparoscopic surgery was 52 minutes. One major, serious intraoperative complication (0.7%) was recorded - injury to the ductus hepaticus communis. Moderate intraoperative complications occurred in 4.5%. Furthermore, one serious early postoperative complication (0.7%) - bleeding from the cystic artery --and one minor (0.7%) - in a patient with acute pancreatitis after endoscopic retrograde cholangiopancreatography - was recorded. Late postoperative complications occurred in 4% of the patients. Conversion of laparoscopic operation with a definitive resolution of the serious condition was performed in one patient because of the aforementioned serious intraoperative complications. Eleven patients underwent intraoperative cholangiography; extraction of stones from the bile duct was performed in six cases.

CONCLUSION

Intraoperative cholangiography in children and adolescents can be recommended as a safe and effective imaging modality for patients with preoperative evidence of biliary obstruction. Laparoscopic cholecystectomy in children and adolescents can be clearly recommended as an effective and safe surgical technique convenient for paediatric patients.

Substituted pyrazinecarboxamides as abiotic elicitors of flavolignan production in Silybum marianum (L.) gaertn cultures in vitro

Substituted pyrazinecarboxamides markedly influenced production of flavonolignans in Silybum marianum callus and suspension cultures. In this study the effect of two compounds, N-(3-iodo-4-methylphenyl)pyrazine-2-carboxamide (1) and N-(3-iodo-4-methylphenyl)-5-tert-butyl-pyrazine-2-carboxamide (2), as abiotic elicitors on flavono-lignan production in callus culture of S. marianum was investigated. Silymarin complex compounds have hepatoprotective, anticancer and also hypocholesterolemic activity. In vitro flavonolignan concentration in cells is very low and the elicitation is one of the methods to increase production. Elicitors were tested at three concentrations and at different culture times. In the case of elicitation with 1, the greatest increase of flavonolignan and taxifoline production was observed at concentration c(1a) after 6-hours of elicitation and after 24 and 72-hours at concentration c(1b). However, increased production of silychristin, one of the compounds in the silymarin complex, was achieved after only 6-hours elicitation with c(1a) (2.95 x 10(-4) mol/L). The content of silychristin was 2-times higher compared to the control sample. An increased production of silychristin was reached with compound 2 at the concentration c(2) (2.53 x 10(-3) mol/L) after 72 h of elicitation. The production of silychristin in this case was increased 12-times compared to control.

Glutamate receptor block in Lurcher mutant mice during ontogeny and its effect on hippocampal long-term potentiation

Basic evaluation of the effect of chronic NMDA glutamate receptor (NMDAR) blockade on the hippocampal long-term potentiation (LTP) was performed in an animal model of inborn olivo-cerebellar degeneration (Lurcher mutant mice, LMM). NMDA receptor antagonist MK-801 was administered to mice in the dose 0.2 mg/kg of body weight, daily during two periods of their ontogeny: D5-D26 and D91-D111. In the consecutive 15 days some behavioral characteristics were studied using special methods for physical activity testing. Then LTP was investigated in LMM and also in their healthy littermates which served as controls (wild-type, WT). LTP in animals pre-treated with MK-801 showed significant long-term suppression of NMDAR activity, in both WT and LMM despite certain small differences between them. Our results show that cerebellar pathology on one hand and a physical activity on the other hand can influence the LTP in hippocampal region. It can be concluded that the results support the ideas of close functional cooperation between the brain structures which are involved in mechanisms of learning and memory.

[Malone antegrade continence enema stoma in children with dysfunctions of pelvic organs]

INTRODUCTION

Regular large intestine cleansing using rectal enemas in patients with impairment of pelvic organs is technically demanding and, frequently insufficient. Defecation is made easier using Malone antegrade continence enema (MACE), which is based on the same principles as continent vesicostomy.

AIM

Assessment of up-to-date experience with the MACE in children.

MATERIAL AND METHODOLOGY

During 2004-2007, the MACE stoma was completed in 7 child patients with spinal dysraphia and severe intestinal dysfunction (meningomyelocele 4x, cerebral palsy 1x, rectal atresia 2x) aged 2-15 y.o.a. In all the subjects, in situ adjusted appendix was used for the construction and, furthermore, continent vesicostomy was performed in two children.

RESULTS

Seven children were followed up for a period of 10-48 months. The enema volume ranged from 100 to 600 ml and it was administered for 20-30 min. The intestine is cleansed within 20-40 minutes. Frequency of the enemas was once daily in 6 patients and every other day in one girl. Complete continence was achieved and obstipation resolved in 5 children, negligible soiling of a diaper lining persisted in 2 subjects. Stenosis of the appendix stoma in two children was managed by its dilation 3 and 5 months postoperatively.

CONCLUSION

MACE stoma facilitates regular cleansing of the large intestine and subsequent establishment of stool continence in patients with spinal dysraphia, as well as in patients with any intestinal dysfunction, requiring regular administration of enemas. It is safe to be used in patients with concomittant continent stoma of the urinary tract.

Particle image velocimetry measurement in the model of vascular anastomosis

Neointimal hyperplasia is the most common complication of all forms of arterial reconstructions. This response of the vascular wall to injury is influenced by many factors, especially, but not limited to, by the hemodynamic profile in the area of vascular anastomosis and in its close proximity. To eliminate this negative influence of hemodynamics on progression of neointimal hyperplasia, we tried to develop anastomosis with optimal hemodynamic parameters. In our experimental study we used Particle Image Velocimetry measurement and 3D blood flow simulation for studying flow characteristics for different length and angles of anastomoses. Based on our experimental studies and numerical simulations we believe that anastomosis with smaller angle demonstrates better hemodynamic parameters, optimal angle being less than 30 dg. Length of anastomosis in this smaller angle anastomosis is app. 2-2.5 of native vessel diameter.

[Laparoscopic surgery varicocele in the childhood and adolescent--our experience with 202 patients]

The aim of this work was to assess benefits and complications of laparoscopic procedures of varicocoelas in children and adolescents, conducted in our clinic.

MATERIAL AND METHODOLOGY

From 2000 to 2004, 202 patients (198 with leftsided, 2 with rightsided and 2 with bilateral varicocoelas) underwent laparoscopic procedures in our clinic. Patients with stage II and III varicocoelas were operated. The median age of the operated patients was 15 years (range 11-18 years). The procedures saved arteries and lymphatics maximally.

RESULTS

During a two-year follow up period, 8 patients (3.96%) relapsed, 21 patients (10.39 %) presented with hydroceolas. No testical hypotrophy was recorded in our patient group. Also, no peroperative complications were recorded during the laparoscopic procedures. The procedures lasted 20.4 min, on average, hospitalization lasted 4.2 days, on average (range 4-6 days).

CONCLUSION

Laparoscopic varicocolectomy, maximally saving arteries and lymphatics, proved a safe method. The rate of complications is similar to that of other treatment procedures of childhood varicocoelas. Rather long term effects considering a quality of hormonal production of testes and seminal counts, than postoperative complications rates, are the main parametres for choice of a treatment method.

[Results of the elective laparoscopic appendectomy in unexplained pains in the right hypogastrium]

AIM

The aim of this study is to assess results of surgical therapy in female patients with clinical diagnoses of unexplained pains in the right hypogastrium.

STUDY GROUP

The study was conducted with a group of female patients, who were indicated for elective laparoscopic appendectomy. All girls underwent complete laboratory and clinical examinations prior to the procedure, and, later, histological findings and peroperative findings were added. The patient group was then re-examined retrospectively. All procedures were conducted at the Clinic of Paediatric Surgery, Orthopaedics and Traumatology in Brno.

METHODOLOGY

A follow-up examination of clinical symptoms was the primary method in the study. After 3 years of the procedure, the girls were asked to fill in a questionnaire, including 5 questions with pre-defined answers. Complete records of 67 female patients were obtained during the period 1997-2000.

RESULTS AND CONCLUSION

Over 80% of the enquired female patients experienced no further symptoms. The study confirmed positive effects of elective appendectomies in unexplained pains in the right hypogastrium.

[Laparoscopic surgical procedures in children with the Hirschprung's disease--initial experience]

Laparoscopically assisted resection of the large intestine in the Hirschprung's disease patients was introduced into practice worldwide in mid 90-ies of the last century. In the Czech Republic this procedure had not been conducted. The aim of this work was to introduce the method in the Czech Republic. In this study the authors present their initial experience with this new method. They have successfully operated three patients with this disorder.

[Video-assisted tenotomy of the triceps muscle of the calf in cerebral palsy patients]

PURPOSE OF THE STUDY

The aim of the study was to demonstrate the outcomes of video-assisted tenotomy of the gastrocnemius and soleus muscles in children with the spastic form of cerebral palsy.

MATERIAL

In the period from September 2003 to March 2004, 18 lower extremities in 14 patients were operated on.A set for endoscopic plastic surgery with a 4-mm trocar was used. Aponeurotomy was carried out with a scalpel no. 11 or arthroscopic scissors. The treated limb was immobilized in plaster cast for 6 weeks. METHODS The inclusion criteria were: an equinus gait free from a valgus or a varus deviation, preferably unilateral, and the age range between 4 and 10 years. The patients were examined before surgery and followed up at 3-month intervals.

RESULTS

In 16 out of 18 treated extremities, simple aponeurotomy of the gastrocnemius and soleus muscles was sufficient to achieve 20 degrees dorsiflexion. In two cases it was necessary to complete the procedure at the same stage by video-assisted sliding double-point tenotomy of the Achilles tendon. The short-term follow-up did not reveal complications such as failure of wound healing or neurological or vascular disturbance.

DISCUSSION

The international literature data show that this method has largely been developed on cadavers. Much attention has been given to potential injury to the sural nerve. However, the ultimate goal of this operation, i. e., sufficient correction, should be regarded as a much more important factor. In older children, simple aponeurotomy may not achieve this objective and therefore the authors developed a procedure combining video-assisted aponeurotomy with sliding double-point tenotomy of the Achilles tendon.

CONCLUSIONS

Video-assisted tenotomy of the gastrocnemius and soleus muscles proved a fully effective method in our group evaluated at short-term follow-up.

[Endoscopic investigations in children under 3 years of age at the clinic of paediatric surgery]

BACKGROUND

Retrospective study of gastroscopic investigations in children under 3 years of age.

METHODS AND RESULTS

Since 1.1.2002 till 31.10.2004 we performed 119 endoscopic investigations in children of this age. 21 patients were excluded because of missed documentation. The average weight of our children was 11.8 kg. (min. 2.8, max 20 kg). In 55 cases suspicion for the oesophageal or gastric corrosion was the reason of investigations. in 24 cases swallowed alien bodies, in 10 patients we performed dilatation of oesophageal stenosis in repeated sessions in 1-6 moths periods. In 4 children we introduced percutaneous endoscopic gastrostomy (PEG), in 3 children ERCP was performed because of cystic dilatation of the bile duct. In I child the supposed hematemesis was the reason of gastroscopy (negative) and in one patient oesophageal varicula were assumed (negative).

CONCLUSIONS

Oesophageal or gastric corrosions were assured in 12 cases (Grade 1.-2.:20.2%). 5 alien bodies couldn't be removed because of peristalsis, 1 object because of its dimensions (25% failures). Our dilations were performed in oesophageal stenosis with bougies or balloon dilator. 9 children were first operated for oesophageal atresia (Vogt IIIb), 1 child was after an operation for oesophageal corrosion with perforation.

[Percutaneous endoscopic gastrostomy in children]

AIM

The authors evaluate their experience with percutaneous endoscopic gastrostomy in children at the age of three months to 14 years.

COHORT

Forty three patients treated with this method in the years 1995-2002.

METHODS

The percutaneous endoscopic gastrostomy is applied in children under general anesthesia. In two patients only it proved to be necessary to convert to open or laparoscopic gastrostomy.

RESULTS

Only minor complications were encountered.

CONCLUSIONS

It became obvious that percutaneous endoscopic gastrostomy is a suitable method to provide long-term enteral nutrition in children of child age who may not be nourished sufficiently by natural ways.

[Laparoscopic surgery of the spleen in children]

Laparoscopic operations of the spleen, incl. splenectomy, are increasingly accepted worldwide. The most frequent indications for this type of surgical treatment are haematological diseases (some types of haemolytic anaemia, thrombocytopenia, myeloproliferative syndrome). Another indication for surgery is hypersplenism from other causes such as vascular anomalies or isolated thrombosis of the lienal vein. The reason for urgent or planned laparoscopy may be also traumatic damage of the spleen (haemorrhage, pseudocysts). In the submitted work the authors present their experience with 21 patients where a laparoscopic operation of the spleen was performed. Of 21 children four were laparoscopically operated on account of a mesothelial cyst or posttraumatic pseudocyst of the spleen (ratio 1:3). In another 15 children laparoscopoc splenectomy was performed for haematological reasons (11 x spherocytosis, 3 x idiopathic thrombocytopenic purpura, 1 x autoimmune haemolytic anaemia). Twice the operation was indicated on account of isolated thrombosis of the lienal vein. In three instances a concurrently, also laparoscopic cholecystectomy was performed and in two liver biopsy. On operation 3-5 troacars were used and the patient was placed in a supine position. In no instance preoperative embolization of the lienal arteries was performed. On treatment of cystic structures of the spleen the authors made in three instances total resection of a cyst--in the upper pole of the spleen, in case of a central localization, only 2/3 resection and fixation of the omentum. In resections recently coagulation and Argon spraying was used. The spleen was extracted by morcellation in a plastic bag or via a 5 cm left-sided subcostal incision (2x). The median size of the spleen was 14.4 cm (10-20 cm), of cystic formations 7.25 cm (6-8 cm). The mean period of operation in splenectomy was 146 minutes. In two patients a blood transfusion was necessary (1x splenectomy, 1x resection of the lower third of the spleen). As to complications the authors recorded once major haemorrhage after splenectomy--resolved by the use of Endo GIA stapler. Conversion was not necessary in any of the operations. The mean period of hospitalization was 6 days.

[Laparoscopy in the diagnosis, classification and therapy of nonpalpable undescended testes]

OBJECTIVE

The use of laparoscopy in children for the diagnosis, classification and treatment of non-palpable testes. High forms of undescended testes in an abdominal or high inguinal position are a diagnostic and therapeutic problem in paediatric surgery.

METHOD

The authors evaluate retrospectively the laparoscopic approach used in 68 boys for the diagnosis, classification and treatment of 79 undescended testes. The mean age of the operated boys was 4.58 years. In 22 (27.9%) agenesis or atrophy of the testis was found (Type I). Thirty-two (40.5%) testes in an abdominal position (Type II) were mobilized laparoscopically, moved to the groin and the operation was completed by open orchidopexy. In 25 cases (31.6%) the laparoscopic method described by Fowler-Stephens was used treatment was completed by orchidopexy in the second stage (Type III and IV).

RESULTS

No serious complications were recorded during or after operation. In two instances (2.5%) after the two-stage Fowler-Stephens operation atrophy of the testis developed.

CONCLUSION

Miniinvasive laparoscopy is considered at present the standard method for the localization and treatment of non-palpable testes.

Gastric carcinoma in a 9-year-old boy

Gastric carcinoma is an extremely rare cancer in children. A case is presented of a 9-year-old boy admitted to The University Hospital Brno with a 4-month history of abdominal pain, anorexia, weight loss, nausea, and vomiting. Several of his family members died from or have been treated for cancer. Barium meal examination performed 2 months prior to admission was nondiagnostic. When gastroendoscopy, laparoscopy, and abdominal computer tomography scan were performed, the diagnosis of adenocarcinoma of the stomach was established. The patient died 10 days after admission because of rapid cancer spread. Miliary metastases of the peritoneum, mesenterium, omentum, liver, bowels, lungs, heart, bone marrow, and skin were found. No penetration through the hematoencephalic barrier was noticed.

[Laparoscopic cholecystectomy in children]

OBJECTIVE

Retrospective evaluation of laparoscopic cholecystectomy in children. The authors deal with the asset of the method in child surgery and emphasize the differences of treatment of cholelithiasis in children by a laparoscopic approach.

METHOD

During 1994 to 1998 the authors made 54 laparoscopic cholecystectomies in children 5 to 18 years old (mean age 14.0 years). The indication for surgery was in 48 patients cholecystolithiasis and in six instances confirmed chronic cholecystitis without concrements. Four times cholecystolithiasis associated with congenital haemorrhagic disease was found. The majority of patients, i.e. 51 (94.4%), was operated during the quiescent stage of the disease.

RESULTS

In the group of operated children no serious peroperative and postoperative complications were recorded. Twice concrements from the bile duct were removed by papillosphincterotomy in cholecystocholedocholithiasis after previous laparoscopic cholecystectomy.

CONCLUSION

In child surgery laparoscopic cholecystectomy is a less frequent operation than in adults. However, it is also in children an effective and safe method with all advantages of mini-invasive operations.

[An unusual esophageal stenosis]

In the submitted case-history the authors describe the case of a child operated after delivery on account of oesophageal atresia type Vogt IIIb. After a two-year interval the child returned on account of acute dysphagia and endoscopy revealed oesophageal stenosis caused by a mucosal strangulating bridge. The latter was removed endoscopically and during a check-up examination 6 months later the endoscopic picture was negative.

[The importance of laparoscopy in children]

The authors submit the evaluation of 720 laparoscopic operations performed at the Clinic of Child Surgery and Traumatology in Brno between the end of 1994 and May 1999. The group is formed by children aged 3 weeks to 18 years. The mean age was 8.4 years. The authors recorded once an early and 4 times a late complication. None of the complications were serious and did not threaten the child's health or life. With regard to ever more frequently performed acute laparoscopy the percentage of conversions (2.5%) is higher. The authors emphasize there is practically no age limit for performing this operation (32 infants and toddlers). On the other hand, perfect technical equipment and adequate training of the whole team is necessary.

The size of the splenic hilus, diameter of the splenic artery and its branches in the human spleen

Sixty spleens were observed according to the size of the splenic hilus depending on the size of the human spleen. The diameter and area of the lumina of the arterial branches were measured in 30 casts of the vascular bed of the spleen. Results were statistically evaluated, tabelated and graphed.

[Present status of minimally invasive surgery in children in the Czech Republic]

In an effort to assess the contemporary position of miniinvasive surgery in children the authors addressed a total of 10 departments. They received replies from nine. The report includes thus all important Czech departments concerned with child surgery incl. miniinvasive operations. The group comprises a total of 1,191 laparoscopic operations and 30 thoracoscopies performed between 1994 and February 1997. The total number of complications was 1.1%. The mean percentage of conversions was 3.1%. The authors did not record any major complications with serious harm to the patient.

[Problems in the diagnosis and treatment of splenic injuries in children]

The diagnosis and treatment of the injured spleen in children changed markedly during the last 20 years. However even when contemporary diagnostic algorithms and therapeutic procedures are used, there are still problems for which we lack an unequivocal answer. Based on their own experience and data in the literature the authors try to contribute to the solution of this important traumatological problem.

[Initial experience with laparoscopic treatment of ileus conditions and lysis of adhesions in children]

Intraabdominal adhesions are important complications after classical laparotomy. The authors describe in their paper their initial experience with the laparoscopic diagnosis and treatment of intraabdominal adhesions in acute ileous conditions in children. Significant adhesions were found in 13 patients. In two invagination was the cause of intestinal occlusion. In one patient torsion of a loop and in one instance they diagnosed a paracaecal abscess. In the remaining three they did not detect the cause of pain after appendectomy. In 2 children they had to convert the operation to classical laparotomy. The group is formed by children aged 4-17 years. The mean age was 12.3 years. In all instances with a positive finding adhesiolysis or solution of another cause of intestinal obstruction had a favourable effect and eliminated the patient's complaints.

[A non-traditional procedure in the surgical treatment of portal hypertension in a child]

The authors present the case-history with a uncommon surgical procedure in a child with portal hypertension and hypersplenism. Half the spleen was resected and concurrently a distal splenorenal anastomosis of the Warren type was created. This procedure was selected because the child had a very enlarged spleen and marked hypersplenism. The postoperative course was free from complications and the satisfactory condition of the child 15 months after operation with normal haematological values confirms the justification of the selected procedure.

[Therapy of bleeding esophageal varices in children--present and future aspects]

The authors' department has devoted the past 25 years to treatment of portal hypertension in children and above all to the most dramatic manifestations-haemorrhage from oesophageal varicosities. In previous years a number of surgical and conservative methods was used. The milestone in therapeutic strategy and tactics was the year 1990 when endoscopic sclerotization of oesophageal varices was introduced as a routine method. Since then 14 patients aged 5-17 years were treated. In addition to sclerotization also medicamentous and surgical treatment are used. The authors evaluate their experience assembled during the past three years and recommend optimal procedures in children. They try also to foresee the future development of therapy.