[EP quiz part 1: Ventricular arrhythmia and tachycardia]

We present the case of a 56-year-old woman without heart disease who perceived a fast heart beat. The Holter ECG showed frequent ventricular premature beats, thus, allowing a tentative diagnosis, which was confirmed electrophysiologically.

Melatonin applied to cucumber (Cucumis sativus L.) seeds improves germination during chilling stress

The relationship between germination and melatonin applied during osmo- and hydropriming was studied in cucumber seeds. The proportion of nuclei with different DNA contents, the mean ploidy and the (2C + 4C = 8C)/2C ratio in unprimed and primed, dry and imbibed at 10 degrees C seeds were established by flow cytometry. Thiobarbituric acid reactive substances and protein oxidation were also estimated. Melatonin and indole-3-acetic acid (IAA) concentrations in the seeds were determined using high-performance liquid chromatography with electrochemical detection. Being sensitive to chilling stress, seeds that germinated well (99%) at 25 degrees C showed only 30% germination at 15 degrees C, and almost no germination (4%) at 10 degrees C. Hydropriming in water improved seed germination to 50-60% at 15 degrees C and the addition of melatonin (25-100 M) also increased the rate of germination. Osmopriming in polyethylene glycol increased germination at 15 degrees C to 78%, and 98% when combined with 50 M melatonin. Osmoprimed seeds germinated even at 10 degrees C and reached 43%, and 83% when 50 M melatonin was applied. None of the treatments induced DNA synthesis, although during the first 24 hr of imbibition at 10 degrees C the mean ploidy and the (2C + 4C = 8C)/2C ratio increased, which is indicative of the advanced Phase II of germination. Hydro- and osmopriming slightly decreased IAA content in the seeds in most of the cases; only hydropriming with 100 and 500 M melatonin increased it. Melatonin protected membrane structure against peroxidation during chilling, but excessive melatonin levels in cucumber seeds (approximately 4 microg/g fresh weight) provoked oxidative changes in proteins. There is still lack of information explained clearly the role of melatonin in plant physiology. This molecule acts multidirectionally and usually is alliged to other compounds.

Acute lymphoblastic leukaemia cells express CCR7 but not higher amounts of IL-10 after CD40 ligation

OBJECTIVE

Production of cytokines that support T-cell activation and proliferation and migration to lymph nodes is one of the most important terms of cancer vaccine development. In previous studies we and others used CD40 ligation to obtain higher expression of co-stimulatory and adhesion molecules on leukaemic cells from children with acute lymphoblastic leukaemia (ALL). This time we assess the cytokine and chemokine gene expression profile in CD40-stimulated ALL cells.

MATERIAL AND METHODS

Malignant cells from 25 children with BCP-ALL were stimulated (or not) with huCD40LT and rIL-4 for 96 h. Eleven different molecule, cytokine and chemokine mRNAs levels (CCR7, IL-23, TGF-beta-IP, IFN-gamma, IL-10, CD1a, CD40, CD54, CD80, CD83, CD86) were determined using the real-time PCR technique with TaqMan chemistry using ready-to-use low-density arrays for gene expression by Applied Biosystems.

RESULTS

1) Increases in mRNA levels for CD40, CD54 and CD80 after CD40L and IL-4 stimulation were observed, 2) CCR7 mRNA expression was higher after CD40 ligation than before the culture (p = 0.002), 3) IL-10 mRNA expression was higher after the culture with medium than before the culture (p = 0.01).

CONCLUSIONS

The results show that leukaemia-derived dendritic cells obtained with CD40 ligation express CCR7 - chemokine is involved in migration to lymph nodes and does not produce higher amounts of IL-10, a potent immunosuppressive cytokine. Our preclinical findings could be used in the design of immunotherapy trials for the treatment of children with ALL.

Effects of selenium administration on blood serum Se content and on selected reproductive characteristics of sheep (short communication)

Abstract. Effects of selenium on certain indicators of sheep reproductive success and on Se level in the sheep's blood serum were studied in 2001–2002 on 100 Polish merino sheep ewes kept in a Western Pomeranian sheep farm. The 100 ewes were picked out on random and divided into two equal groups: treatment and control. The blood samples for serum Se assays were collected prior to administration of sodium selenide (before servicing) and 7 days after the treatment. The study was aimed at determining Se effects on the reproductive success (fecundity) of ewes and on selected indicators of lamb utility in a Se-deficient area. Se administration prior to servicing enhanced the herd’s reproductive success. The treatment group’s litter size was by 0.38 lamb per ewe higher than that of the control. The control group lamb body weight was lower than that of the treatment group by an average of 0.23 kg on birth and 0.31 kg 33 days later.

[Avoidance of intermittent T-wave oversensing with device programming]

We report the case of a 35-year-old man who was suffering from severe heart failure due to cardiomyopathy. He underwent heart transplantation years ago and developed complex ventricular arrhythmias in the following months in combination with recurrent episodes of syncope due to hypertrophic non-obstructive cardiomyopathy in the transplanted heart, so a dual chamber ICD was implanted. Months later repetitive episodes of intermittent T-wave oversensing with consecutive activation of the ICD could be observed. Surgical revision of the electrode was performed and the patient was closely followed up. One year later, further episodes of T-wave oversensing led to multiple inappropriate IDC-shocks. A very short AV-conduction time was programmed to allow ventricular capture whenever possible, because T-wave oversense after ventricular capture would be annotated as single ventricular ectopy not resulting in antitachycardia pacing. As a consequence, the patient was free from inappropriate ICD-shocks, but showed several shorter episodes of T-wave oversensing. They were all initiated by atrial activity that was seen in the refractory period, thus leading to a loss of AV synchrony. Programming a very short post ventricular atrial refractory period (PVARP) in addition to a short AV-delay led to the complete disappearance of T-wave oversensing in this patient. During a 9-month follow-up, no further tachycardia episodes were detected by the device.

[Successful radiofrequency catheter ablation of an accessory pathway in the right free wall using combination a long vascular sheet and a mapping catheter in the right coronary artery]

We present a patient with an accessory pathway difficult to ablate in the right free wall. Two prolonged and failed attempts at radiofrequency catheter ablation of this accessory pathway in other institutions led to a third attempt in our hospital. Successful outcome of accessory pathway ablation was achieved by mapping the right free wall using an intracoronary catheter in the right coronary artery. A long vascular sheeth was introduced in the right femoral vein, manipulated into the tricuspid anulus, which allowed a stable catheter position with adequate tissue contact of the ablation catheter at the target site. The combination of exact mapping and adequate tissue contact of the ablation catheter as described above facilitated successful outcome in this patient. Further investigation is necessary to determine the role of this technique as first choice therapy in patients prone to develop recurrence of accessory pathway conduction or primary failure of catheter ablation.

Transversal crista terminalis conduction suggests ineffective bidirectional isthmus block

Catheter ablation of the posterior isthmus is an effective tool to cure typical atrial flutter. In some cases, however, bidirectional block cannot be obtained despite extensive RF applications. Anatomic obstacles or abnormalities are thought to be the most common reasons for failed or prolonged procedures. We present a case of recurrent typical atrial flutter that seemed to be refractory to all ablation attempts in the region of the posterior isthmus although no anatomic abnormalities could be detected. Despite extensive RF application, bidirectional conduction was unchanged. Using a novel noncontact mapping system (En-Site 3000) the existence of a fast conducting gap in the region of the inferior terminal crest was revealed. Rapid conduction over this gap to the opposite side of the isthmus led to the impression that bidirectional isthmus block was not established. As a result no further RF applications were necessary because isthmus block was complete at that time. This is the first time that transverse conduction across the terminal crest could be detected by this novel noncontact mapping system masquerading as unchanged bidirectional isthmus conduction.

Catheter inversion to achieve complete isthmus block in patients with typical atrial flutter

Endocardial catheter ablation is now considered as the therapy of first choice in highly symptomatic patients with recurrent atrial flutter. Despite of primary success rates between 90 and 100% complete isthmus block is sometimes hard to achieve. We present ablation results of 100 consecutive patients suffering from typical right atrial flutter. After a mean of 18 energy applications persistent bidirectional isthmus block could not be achieved in 16 patients and right atrial angiography was performed in all of them. In 9 patients a large Eustachian valve was detected and considered responsible for failure of endocardial catheter ablation of atrial flutter. Catheter manipulation targeting the anterior region of the Eustachian ridge was successful in all patients after looping the ablation catheter within the right atrium. With a mean of 3 additional RF applications, 6 of the 9 affected patients could be successfully ablated. Large Eustachian ridges are not a rare finding in patients undergoing ablation of typical right atrial flutter. Inversion of the ablation catheter within the right atrium is a simple technique providing excellent tissue contact of the ablation electrode with the anterior region of the Eustachian Ridge. Using this approach, the creation of bidirectional isthmus block is possible in the majority of the respective patients.

Successful catheter ablation of a slow AV-nodal pathway from the left posteroseptal region

We present the case of a 44 year old woman with recurrent episodes of supraventricular tachycardia due to AV-nodal reentry (AVNRT). She was refractory to conventional medical treatment and referred to our hospital with the view to catheter ablation of the slow AV-nodal pathway. AVNRT of the common type was easily induced performing stimulation from the high right atrium and proximal coronary sinus. Other forms of supraventricular tachycardia were definitely ruled out during further electrophysiologic study. Repetitive RF applications around the right posteroseptal region failed to cure the tachycardia which remained inducible with a typical jump in the AH interval. Extensive RF applications from posteroinferior to the midseptum including the area of the proximal coronary sinus and its os were ineffective as well.AVNRT was transiently but reproducibly eliminated while burns were applied to the high midseptum but AVNRT reoccured within 20 minutes. Finally after retrograde passage of the aortic valve with a 4 mm tip ablation catheter, RF was applied to the left postero to midseptal region. An accelerated junctional rhythm was immediately observed and AVNRT remained non-inducible from that time onwards. It is concluded that an atypical posterior extension of the AV node with predominant leftatrial course might be responsible for this unusual success of slow pathway elimination from left posteroseptal.

In vitro sensitivity of leukemic cells to nucleoside derivatives in childhood acute leukemias: good activity in leukemic relapses

Nucleoside analogues such as fludarabine and cladribine are used in therapy of indolent lymphomas and leukemias in adults, while cytarabine is used mainly in protocols for acute leukemias. Mechanisms of their activity is based on inhibition of enzymes involved in DNA, RNA and protein synthesis. The objective of the study was the analysis of in vitro cellular drug sensitivity in childhood acute lymphoblastic (ALL) and myeloid (AML) leukemia. Isolated leukemic cells obtained from 264 patients, including 152 initial ALL, 45 relapsed ALL, 54 initial AML and 13 relapsed AML were tested for cytotoxicity for fludarabine, cladribine, and cytarabine by the MTT assay. Drug concentration lethal to 50% of tested cells was regarded as a value of drug resistance. Three tested nucleoside analogues showed highest cytotoxicity against initial ALL samples. Samples of relapsed ALL and initial AML were more resistant than ALL de novo ones. Unexpectedly, no differences were observed between initial and relapsed AML samples for all tested drugs, what suggests that nucleoside analogues are active drugs in relapsed AML, which is commonly regarded as a resistant disease. All tested drugs presented significant cross-resistance in each of analyzed subgroups. In summary, tested nucleoside analogues presented relatively good activity against childhood leukemias at relapse stage.

Remaining problems and controversies in the management of childhood head and neck soft tissue sarcomas: Retrospective (national) Multicenter Study of the Polish Pediatric Solid Tumors Group

Soft tissue sarcomas in children are a heterogeneous group of malignant diseases. Among these, tumors localized in the head and neck region are especially difficult to treat. While multidisciplinary care has dramatically improved the prognosis of sarcoma patients, their treatment remains uncertain because of demand on radical surgical resection of the tumor. Achieving cure without deforming or mutilating the child remains the primary goal of treatment. This study is the multicenter (nationwide, 11 Polish centers) retrospective analysis of the treatment results in children having soft tissue sarcoma in the head and neck region during the previous decade (from 1991 to 2001). Late effects of the treatment are documented in long-term survivals. Eighty-five children from 1 to 212 months of age were included. Different multimodal treatment protocols were utilized (CWS-91, SIOP-MMT-91, and CWS-96). The median observation time was 25 months. Data on long-term effects were collected in 34 long-term survivals. Complete remission was achieved in 68 (80%) patients. Primary treatment failure occurred in 13 (15.3%) patients, all of whom succumbed in disease progression. Relapse occurred in 21 (30.9%) patients primarily achieving complete remission. Second primary neoplasm occurred in 3 children. The estimated 5-year event-free survival and the 5-year total survival rates for the whole group are 0.38 and 0.55, respectively. The main late effect documented in long-term survivals were cosmetic defects in 12 (35.3%) and visual field deficit or blindness in 8 (26.5%). Despite substantial improvement of the prognosis of pediatric soft tissue sarcomas, the multimodal treatment of head and neck region tumors remains controversial. Improved long-term outcome and focusing on psychosocial difficulties raise the important and difficult problem of functional results and cosmesis. Tumors localized in the orbit carry an excellent prognosis. However, the main late sequela is vision impairment and cosmetic defect due to the therapy given many years earlier. Two other tumor localizations--the parameningeal and nonparameningeal ones--still have bad prognosis. The observations made in this study confirm that main prognostic factors are the size of the primary tumor and the tumor stage. The worst prognosis remains invasive tumor (T2-stage) with a size over 5 cm. Individually adjusted multimodal therapy, which imperatively needs to be radical, though not mutilating, might minimize the late effects. Psychosocial problems in long-term survivors need to be focused on at the national level and better support must be provided in the future, involving a team of different medical and paramedical profiles.

Preoperative brachytherapy in endometrial cancer--proposal of a new clinical protocol

High-dose rate brachytherapy preoperative treatment has been described. The proposal of a protocol contains an outline of patient qualifications for this kind of treatment, as well as necessary laboratory and diagnostic imaging examinations. Methods of brachytherapy (low-dose rate and high-dose rate), methods of surgery and postoperative management of patients with endometrial cancer are discussed.

[Preliminary results of BFM 96 protocol in treatment of childhood ALL relapse in the experience of the Polish Paediatric Leukaemia /Lymphoma Study Group]

Between 1998 and 1999, 36 children aged from 3 months to 18 years (10 girls and 26 boys) with first relapse of acute lymphoblastic leukaemia were included in the study. The children were treated according to the BFM 96 relapse protocol. There were 24 cases with early (including 9 children with very early) and 12 cases with late relapse ( BM-20, local extra BM-6, combined 10). The overall second complete remission (CR) rate was 83,33%. The probability of overall EFS after 2 years was 73,3%. The results obtained with BFM 96 chemotherapy in children with first late relapse are acceptable. For children with early relapses, megachemotherapy with BMT in second remission should be used.

Influence of 3 antivertiginous medications on the vigilance of healthy volunteers

In the present randomized, comparative, double-blind, 3-way crossover study, possible effects of 3 antivertiginous medications on vigilance were investigated. 30 healthy volunteers received single doses of a fixed combination of cinnarizine 20 mg and dimenhydrinate 40 mg (Arlevert, ARL), dimenhydrinate 50 mg, or betahistine dimesylate 12 mg, in randomized order at 1-week intervals. Spontaneous brain electrical activity (EEG), acoustic late evoked potentials (ALEP) with P300, and reaction time were measured before and 90 (t90) and 180 minutes (t180) after drug intake. All 3 medications led to a delay of P300 (primary criterion) and a decrease of its amplitude. The maximum delay at t180 was found for dimenhydrinate (16.42 ms) and the lowest for betahistine (6.33 ms). Differences ARL vs dimenhydrinate and ARL vs betahistine were not statistically significant (p > 0.05). Spectral analysis of spontaneous EEG showed slight and similar decreases in the power in the a-band under dimenhydrinate and ARL (p = 0.07 and p = 0.03 with respect to baseline, respectively), but basically no change under betahistine. There was no effect on reaction time by either medication. None of the subjects reported drowsiness or any other adverse event. The findings confirm the reported suitability of P300 latency for measurement of drug effects on brain activity, but provide no indication of concomitant impairment of performance capacity by the tested drugs. Global assessment of the results suggests that the fixed combination cinnarizine 20 mg/dimenhydrinate 40 mg exerts only a minor effect on vigilance, not significantly different from betahistine, which is commonly regarded as a non-sedating antivertiginous drug

Development of orally active nonpeptidic inhibitors of human neutrophil elastase

5-Amino-2-phenylpyrimidin-6-ones, some of their desamino derivatives, and miscellaneous derivatives were synthesized and biologically evaluated on both in vitro activity and oral activity in an acute hemorrhagic assay. These compounds contained an alpha-keto-1,3,4-oxadiazole moiety to bind covalently to the Ser-195 hydroxy group of human neutrophil elastase (HNE). Among those tested, compounds 11a-c,e,i-l(F), 11d,e,k(H), 21d,e,k(F), and 21d,e(H) showed a good oral profile. RS-Mixture 3(H) was selected for clinical evaluation based on its oral potency, duration of action, enzyme selectivity, safety profile, and ease of synthesis. Structure-activity relationships (SARs) are discussed.

Effects of 8-OHDPAT administration into the dorsal raphe nucleus and dorsal hippocampus on fear behavior and regional brain monoamines distribution in rats

The effects of R(+)-8-hydroxy-dipropylaminotetralin (8-OHDPAT) administration into the dorsal raphe nucleus (DRN) or bilaterally into the dorsal hippocampus (HIP) on fear behavior in a modified version of the light-dark transitions test and regional brain monoamines (NA, DA, 5-HT) and their metabolites (MHPG, DOPAC, 5-HIAA) in the hypothalamus, midbrain central gray matter, amygdala, hippocampus and pons were examined. The experiments were performed on 36 male, 3-month old Wistar rats. Administration of 8-OHDPAT (200 ng) into the DRN reduced time out from the illuminated part of the chamber and time of motionless behavior in the illuminated part, increased the number of returns from the dark to illuminated part and number of head dipping from the dark to illuminated part without effect on time of motionless behavior in the dark part and on time of locomotor activity in the illuminated as well as in dark part of the chamber. HPLC analysis showed reduction of 5-HT content in the midbrain and amygdala, reduction of 5-HIAA content in pons, increased 5-HIAA/5-HT ratio in the hippocampus and increased DOPAC/DA ratio in the hypothalamus, midbrain, hippocampus and pons without affecting the MHPG/NA ratio and NA content. The administration of 8-OHDPAT (100 ng per site) into the HIP reduced time out from the illuminated part of chamber, time of locomotor activity in the illuminated part and head dipping from the dark to illuminated part without effect on the number of returns from the dark to illuminated part, time of locomotor activity in the dark part and time of motionless in the illuminated as well as in the dark part of chamber. HPLC analysis showed reduction of NA content in the hypothalamus, amygdala and pons, increased the MHPG content in all the investigated structures, increased MHPG/NA ratio in all the investigated structures except the hypothalamus. Dopamine content decreased in the hypothalamus and amygdala, and DOPAC/DA ratio increased in the amygdala and hippocampus. Concentrations of 5-HT, 5-HIAA and 5-HIAA/5-HT ratio were unchanged. The results obtained indicate that 8-OHDPAT acting on the pre-synaptic 5-HT1A receptors decreases fear behavior and acting on 5-HT1A post-synaptic receptors increases fear behavior in the light-dark transitions test. The neurochemical base of anxiolytic and anxiogenic effects evoked by 8-OHDPAT is being discussed.

Predicting the reactivity of proteins from their sequence alone: Kazal family of protein inhibitors of serine proteinases

An additivity-based sequence to reactivity algorithm for the interaction of members of the Kazal family of protein inhibitors with six selected serine proteinases is described. Ten consensus variable contact positions in the inhibitor were identified, and the 19 possible variants at each of these positions were expressed. The free energies of interaction of these variants and the wild type were measured. For an additive system, this data set allows for the calculation of all possible sequences, subject to some restrictions. The algorithm was extensively tested. It is exceptionally fast so that all possible sequences can be predicted. The strongest, the most specific possible, and the least specific inhibitors were designed, and an evolutionary problem was solved.

A low-level X chromosome mosaicism in mares, detected by chromosome painting

Fluorescence in situ hybridization with the use of the equine X whole chromosome painting probe was carried out on chromosome spreads originating from three mares with poor reproductive performance (infertility, miscarriage or stillbirth). The numbers of analysed spreads were high (105, 300 and 480) and in all three mares a low frequency of mosaicism was identified. The mares had the following karyotypes: 64,XX/63,X/65,XXX (93.6%/5.7%/0.7%), 64,XX/63,X (98.9%/1.1%) and 64,XX/63,X (94.3%/5.7%). The incidence and importance of the low percentage X chromosome mosaicism are discussed.