Author Correction: Micronuclei in germ cells of hybrid frogs from Pelophylax esculentus complex contain gradually eliminated chromosomes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Micronuclei in germ cells of hybrid frogs from Pelophylax esculentus complex contain gradually eliminated chromosomes.

In most organisms, cells typically maintain genome integrity, as radical genome reorganization leads to dramatic consequences. However, certain organisms, ranging from unicellular ciliates to vertebrates, are able to selectively eliminate specific parts of their genome during certain stages of development. Moreover, partial or complete elimination of one of the parental genomes occurs in interspecies hybrids reproducing asexually. Although several examples of this phenomenon are known, the molecular and cellular processes involved in selective elimination of genetic material remain largely undescribed for the majority of such organisms. Here, we elucidate the process of selective genome elimination in water frog hybrids from the Pelophylax esculentus complex reproducing through hybridogenesis. Specifically, in the gonads of diploid and triploid hybrids, but not those of the parental species, we revealed micronuclei in the cytoplasm of germ cells. In each micronucleus, only one centromere was detected with antibodies against kinetochore proteins, suggesting that each micronucleus comprises a single chromosome. Using 3D-FISH with species-specific centromeric probe, we determined the role of micronuclei in selective genome elimination. We found that in triploid LLR hybrids, micronuclei preferentially contain P. ridibundus chromosomes, while in diploid hybrids, micronuclei preferentially contain P. lessonae chromosomes. The number of centromere signals in the nuclei suggested that germ cells were aneuploid until they eliminate the whole chromosomal set of one of the parental species. Furthermore, in diploid hybrids, misaligned P. lessonae chromosomes were observed during the metaphase stage of germ cells division, suggesting their possible elimination due to the inability to attach to the spindle and segregate properly. Additionally, we described gonocytes with an increased number of P. ridibundus centromeres, indicating duplication of the genetic material. We conclude that selective genome elimination from germ cells of diploid and triploid hybrids occurs via the gradual elimination of individual chromosomes of one of the parental genomes, which are enclosed within micronuclei.

Myocardial perfusion SPECT with dipyridamole stress test in cardiac syndrome X.

UNLABELLED: Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. AIM of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. PATIENTS, METHODS: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using (99m)Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of (99m)Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point -- normal uptake, 4 points -- no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). RESULTS: Mean SRS was 7.9 +/- 4.8 and mean SSS was 7.2 +/- 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: 1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, 2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, 3) in 20 patients (29.4%), no significant change of the myocardial perfusion between rest and stress images occurred. CONCLUSIONS: In cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology.

Heat transfer from protein crystals: implications for flash-cooling and X-ray beam heating.

Three problems involving heat transfer from a protein crystal to a cooling agent are analyzed: flash-cooling in a cold nitrogen- or helium-gas stream, plunge-cooling into liquid nitrogen, propane or ethane and crystal heating in a cold gas stream owing to X-ray absorption. Heat transfer occurs by conduction inside the crystal and by convection from the crystal's outer surface to the cooling fluid. For flash-cooling in cold gas streams, heat transfer is limited by the rate of external convection; internal temperature gradients and crystal strains during cooling are very small. Helium gas provides only a threefold improvement in cooling rates relative to nitrogen because its much larger thermal conductivity is offset by its larger kinematic viscosity. Characteristic cooling times vary with crystal size L as L(3/2) and theoretical estimates of these times are consistent with experiments. Plunge-cooling into liquid cryogens, which can give much smaller convective thermal resistances provided that surface boiling is eliminated, can increase cooling rates by more than an order of magnitude. However, the internal conduction resistance is no longer negligible, producing much larger internal temperature gradients and strains that may damage larger crystals. Based on this analysis, factors affecting the success of flash-cooling experiments can be ordered from most to least important as follows: (1) crystal solvent content and solvent composition, (2) crystal size and shape, (3) amount of residual liquid around the crystal, (4) cooling method (liquid plunge versus gas stream), (5) choice of gas/liquid and (6) relative speed between cooling fluid and crystal. Crystal heating by X-ray absorption on present high-flux beamlines should be small. For a fixed flux and illuminated area, heating can be reduced by using crystals with areas normal to the beam that are much larger than the beam area.

Ambulatory electrocardiographic evaluation of the heart in patients treated by megachemotherapy and bone marrow transplantation.

The aim of the study was evaluation of the frequency of conduction defects and cardiac arrhythmias before and one month (once a week) after bone marrow transplantation (BMT). It was evaluated by 24-hour electrocardiography based on the Holter's method. There were 50 patients (mean age 29.0 years) examined who were treated with megachemotherapy based on BuCy2, BuCy4 (busulphan and cyclophosphamide), BEAM (carmustine, etoposide, cytarabine, melphalan) and dexaBEAM (dexa-dexamethason) programs before BMT. No heart conduction defects occurred. The mean heart rate increased after BMT. Tachycardia (> 100/min) was observed in 92.5-98.1% of patients and bradycardia (< 60/min) in 41.6-68.0% patients. In 6% of patients bradycardia below 40/min occurred. The heart rate was increased in patients who previously used anthracycline antibiotics, had anaemia or fever, and in patients after autologous BMT (p < 0.05). The complex ventricular extrasystoles were detected in 20% of patients before megachemotherapy. They were more frequently observed in patients with hypokalemia (p < 0.05). After therapy these extrasystoles were observed in a total of 24% patients. There was a statistically significant correlation between this kind of extrasystole and age. The extrasystoles developed mainly in young men. In 10% they occurred de novo and also mainly in men. The heart failure (III degrees, IV degrees according to NYHA) occurred in 14% of patients and death caused by heart (or multiorgan) damage in 18%. Older patients and those who had higher mean heart rate during the first month after BMT were dying more frequently (p < 0.05).

X-ray beam/biomaterial thermal interactions in third-generation synchrotron sources.

Third-generation synchrotron sources generate strong X-ray beams. The beam's interaction with biomaterials gives rise to concerns related to thermal damage and radiation damage. Of the two issues, the thermal interaction is conducive to rigorous analysis from first principles, although this has not been performed to date in a comprehensive manner. In this study, the interaction of the X-ray beam emanating from a third-generation synchrotron with a typical frozen biocrystal is theoretically studied, focusing specifically on the resulting unsteady (time-dependent) and steady heat-transfer phenomena. A unique regime map is developed to explain and to identify, on the basis of Fourier and Biot numbers as governing parameters, the applicable mathematical models that predict the subsequent thermal behavior. Depending on the values of these parameters, some simplified but realistic 'generic' solutions are generated that are suitable for that particular domain of applicability. Classical heat-transfer theory was used to describe the third-generation X-ray beam and biomaterial thermal interaction. Besides the generalized approach presented, numerous illustrative cases were solved and the resulting temperature levels are explicitly presented. Overall, the resulting thermal behavior of the system, i.e. peak and local temperature distribution, during both early transient development and for sustained long-time steady-state conditions, depends on a number of factors including the amount of energy absorbed, convective heat-transfer film coefficient and gas temperature, the sample size and shape, and the thermophysical properties of the sample and cooling gas. Results of the analysis revealed the strong influence that convection has on the transient and final steady-state temperature of the sample and the impact of internal heat conduction. The characteristic timescales of the important and dominant thermal processes with respect to the two types of thermal models are clearly identified.

The effects of dipyridamole stress test on plasma levels of soluble adhesion molecules intracellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and L-selectin in patients with ischemic heart disease and patients with syndrome X.

BACKGROUND: Adhesion of activated leukocytes to the endothelium as a result of myocardial ischemia/reperfusion has been shown to be involved in the development of tissue injury. Leukocyte adhesion to the endothelium occurs via adhesion molecules expressed on the surface of both cell types. Upon cell activation these proteins may be released into the circulation and measured in a soluble form. AIM: To verify whether the dipyridamole stress test, performed in patients with ischemic heart disease (IHD) and in patients with syndrome X, modifies plasma levels of the soluble adhesion molecules vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin and L-selectin. METHODS: Plasma levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, as well as of the soluble leukocyte adhesion molecule L-selectin, were measured in venous blood samples taken before and 7 min after administration of dipyridamole in patients with IHD, patients with syndrome X and healthy individuals. Myocardial perfusion was evaluated using single photon emission tomography. The plasma levels of soluble VCAM-1, ICAM-1, E-selectin and L-selectin were all measured using enzyme-linked immunosorbent assays. RESULTS: After infusion of dipyridamole, plasma levels of ICAM-1 increased significantly in patients with IHD, whereas they remained unchanged in patients with syndrome X and in the control group. In patients with IHD, the initial plasma levels of VCAM-1, E-selectin and L-selectin, before administration of dipyridamole, were higher than those observed in patients with syndrome X and than those in the control group. Plasma levels of soluble VCAM-1, E-selectin and L-selectin decreased significantly in patients with IHD following the dipyridamole stress test, whereas they remained unchanged in patients with syndrome X, and in the control group. CONCLUSION: In patients with IHD, administration of dipyridamole induces myocardial ischemia resulting in modification of plasma levels of the soluble adhesion molecules.

Intense acute phase response in ischemic patients.

The aim of this study was to estimate the qualitative and quantitative changes of acute phase proteins in patients suffering from coronary heart disease. The study was carried out on 74 patients and 12 healthy volunteers. The patients were divided into three groups as follows: patients with myocardial infarction (n=37), Group I--without heart failure, Group II--with heart failure (II-III NYHA), Group III--patients with unstable angina pectoris (n=35); controls-healthy volunteers (n=12). The immunological measurements were performed at the beginning of hospitalisation (point 0), after 4, 8, 12 and 72 h, and after 6, 9 and 12 days of hospitalisation. The concentrations of C-reactive protein (CRP), alpha1-acid glycoprotein (AGP) and alpha1-antichymotrypsin (ACT) were measured using rocket immunoelectrophoresis according to Laurell. Glycosylation profiles of AGP and ACT were determined using crossed affinity immunoelectrophoresis with Con A as ligand according to Bøg-Hansen. Between Groups I and II statistically significant differences were observed for all investigated parameters. Highest concentration values were observed for Groups II and III; for Group II they appeared earlier than for Group III. The maximal values for reactivity coefficients (AGP-RC and ACT-RC) were observed earlier than the respective maximal values of concentrations. Continuous activation occurring in unstable angina leads to a more rapid increase in the concentrations of acute phase proteins and more marked alterations in their glycosylation profiles. In a way these patients seem to be 'primed' with constant stimulation, so that they respond dramatically to the stimulus of ischemia.

Plasma chemotactic activity during dipyridamole induced myocardial ischemia.

BACKGROUND: We have previously reported that transient myocardial ischemia induced during exercise or dipyridamole challenge leads to the release of increased amounts of hydrogen peroxide into circulating blood. It would indicate that the temporary functional changes within myocardial cells may constitute there a sterile inflammatory area. Therefore we decided to evaluate the chemotactic properties of plasma in patients undergoing dipyridamole provocative test, as a sign of released inflammatory mediators. The ischemia occurrence was evaluated with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood samples were obtained from the peripheral vein of 42 patients (18 men and 24 women, mean age 61 years). Plasma chemotactic activity was determined by the use of the Boyden chamber method: immediately before dipyridamole challenge (time 0), 7, and 30 min after drug infusion. The migration of control polymorphonuclear neutrophils towards evaluated plasma samples was estimated. RESULTS: Chemotaxis of control PMNs towards plasma isolated from patients without signs of myocardial ischemia 7 min after dipyridamole administration was significantly diminished in comparison with baseline values (p=0.003). Plasma obtained 7 min after dipyridamole infusion from patients manifesting signs of myocardial ischemia by SPECT attracted control PMNs significantly more intensively in comparison to plasma isolated at time 0 (p=0.0005). CONCLUSIONS: The obtained results indicate that transient myocardial ischemia induced by dipyridamole challenge leads to generation of chemotactic factors detectable in peripheral blood plasma.

Binding of monoclonal antibodies to platelet glycoproteins Ib and IIb/IIIa in uremic patients.

In this study, we have found a reduced binding of monoclonal antibodies (CD42b and CD41a) to glycoproteins Ib and IIb/IIIa of uremic platelets. Presumably, this was due to the altered structure of the sugary part of these glycoproteins. Change in the glycoprotein composition may have effected the disturbed adhesion and aggregation of uremic platelets.

Clinical evaluation of the effect of a hydrogen peroxide mouth rinse, sodium bicarbonate dentifrice, and mouth moisturizer on oral health.

The objective of this 60-day single-blind, parallel trial, using 150 subjects, was to evaluate the effect of a 20% sodium bicarbonate dentifrice, a 1.5% hydrogen peroxide solution and a mouth moisturizer on oral tissues and microflora. Subjects were randomly assigned to one of five groups. The treatments were: 1) Sage dentifrice (sodium bicarbonate). Toothette Plus containing baking soda saturated with the hydrogen peroxide solution and use of a mouth moisturizer, 2) Crest dentifrice, Toothette Plus containing baking soda saturated with the hydrogen peroxide solution and use of a mouth moisturizer, 3) Crest dentifrice, Toothette Plus containing baking soda with a control solution and no mouth moisturizer, 4) Crest dentifrice, Toothette (without baking soda), saturated with a control solution and no mouth moisturizer, and 5) Crest dentifrice, Toothette saturated with 1.5% flavored H2O2 and no mouth moisturizer. From a subgroup of 35 patients (seven from each group) buccal smears for exfoliative cytology were taken as were supragingival microbiological samples from the mesial aspect of first molars (pooled). Buccal smears were evaluated for signs of histopathological changes. Microbiological samples from supra- and subgingival plaque for P. gingivalis, P. intermedia, A. actinomycetemcomitans. A viscosus, F. nucleatum, F. sanguis and C. albicans were evaluated. Clinical parameters measured were a stain index (SI), the modified gingival index (MGI), and a plaque index (PI). There were no adverse changes in the oral microflora and no anaplastic or other pathological changes in any subjects. Clinical parameters showed a statistically significant reduction in the MGI ranging from 26.7-29.9% with no significant differences among the groups (p > 0.05). The PI showed small reductions in all groups except group 2, but the differences were not statistically significant from each other or baseline (p > 0.05). The SI revealed slight increases in all groups and no differences among the groups. It can be concluded that use of Sage dentifrice, Toothette Plus saturated with Perox-A-Mint and Sage Mouth Moisturizer are safe to oral tissues. Using these components did not result in clinically noticeable stain formation, promote plaque formation, or produce any significant adverse changes in the oral microflora.

The influence of electrical cardioversion on superoxide anions (O2-) production by polymorphonuclear neutrophils, hydrogen peroxide (H2O2) plasma level and malondialdehyde serum concentration.

We studied the influence of electrical cardioversion on unstimulated and stimulated superoxide anion production by polymorphonuclear neutrophils in 22 patients with atrial flutter or atrial fibrillation. We also estimated hydrogen peroxide plasma level, as well as malondialdehyde serum concentration, in these subjects. We noted an increase in spontaneous production of superoxide anions from 14.9 +/- 1.8 nmol/10(6) neutrophils per 20 min to 21.37 +/- 2.7 nmol/10(6) neutrophils per 20 min (P = 0.002) in neutrophils obtained after electrical cardioversion. Similarly, stimulated production of O2- also increased after electrical cardioversion (41.8 +/ 3.4 nmol/10(6) neutrophils per 20 min vs. 59.0 +/- 5.9 nmol/10(6) neutrophils per 20 min, P = 0.0027). Moreover, hydrogen peroxide plasma level increased significantly after electrical cardioversion (39.9 +/- 6.2 mumol/l vs. 53.4 +/- 7.6 mol/l, P = 0.003). Serum malondialdehyde concentration also increased after countershock (2.56 +/- 0.26 nmol/ml vs. 2.94 +/- 0.26 nmol/ml, P = 0.023). These results seem to indicate that electrical cardioversion may lead to polymorphonuclear neutrophils activation, increased H2O2 production and lipid peroxidation.

The first 15 minutes of hemodialysis does not affect platelets.

In the study, platelet count and volume, granulocyte number, binding of monoclonal antibodies to platelet glycoproteins Ib and IIb/IIIa were evaluated in hemodialyzed patients. Exclusively, the granulocyte count dropped significantly at 15 minutes after the initiation of dialysis as compared to predialysis samples. It seems that contemporary used cuprophane dialyzer membrane is more biocompatibile and does not have major impact on platelets.

Changes of acute phase proteins glycosylation profile as a possible prognostic marker in myocardial infarction.

In 24 consecutive patients with myocardial infarction, the concentrations of C-reactive protein, alpha 1-acid glycoprotein and alpha 1-antichymotrypsin, as well as acid alpha 1-glycoprotein and alpha 1-antichymotrypsin glycosylation profiles were estimated. Blood samples were taken at admission, after 4, 8, 12 and 24 h, on 2, 3, 6, 9, and 12 days of hospitalization. All studied patients were divided into 2 groups: 12 patients without clinical or radiological symptoms of acute heart failure and 12 patients with acute heart failure. The results of all investigations were tested statistically to appraise significance of differences between the two investigated groups. At admission, as well as after 6 and 12 h, C-reactive protein concentration was significantly higher in patients who developed heart failure. Similarly, the glycosylation profile of alpha 1-antichymotrypsin, reported as reactivity coefficient, was of good prognostic value from the first time-point on. Development of acute cardiac failure seemed to correlate more with the magnitude of inflammatory reaction (measured by changes in acute phase proteins) than with enzymatically estimated infarct size.

Metabolic control quality and free radical activity in diabetic patients.

The role of oxidative/reductive balance derangement in the pathogenesis of diabetic microangiopathy has often been discussed in the last few years. Therefore, we decided to evaluate the influence of intensive insulin therapy on selected indicators of free radical production. The levels of plasma hydrogen peroxide (H2O2) and serum malonyldialdehyde (MDA) were estimated in 15 patients with Type 1 and 15 with Type 2 diabetes before and after 2 weeks of intensive treatment. The initial H2O2 and MDA levels in all cases were significantly higher than in controls. After 2 weeks of treatment, the values for both estimated parameters were significantly lower; however, they were still higher than in the control group. Our results seem to confirm the previous suggestions concerning the relation between metabolic disturbances and oxidative stress in diabetic patients.

[Non-Hodgkin's lymphoma in a patient after many years of remission of Hodgkin's disease]. / Nieziarniczy chloniak zlosliwy u chorej z wieloletnia remisja choroby Hodgkina.

Authors present 38-years old woman with 11-years lasting complete remission of Hodgkin's disease who was recognized to have non-Hodgkin's lymphoma of the base of the tongue and also of stomach three months later. After polychemotherapy complete remission was achieved.

Estimation of hydrogen peroxide plasma levels in patients evaluated for coronary heart disease using dipyridamole infusion followed by SPECT.

BACKGROUND: Prolonged ischemia leads to myocardial infarction and increased formation of toxic oxygen radicals. These substances exert deleterious effects on myocardial cells, contributing to reperfusion injury and generation of arrhythmia. Little information is available, however, concerning the toxic oxygen species generated during transient ischemia. The purpose of our study was to estimate hydrogen peroxide plasma levels in patients subjected to short-lasting ischemia induced by a dipyridamole stress test used for the diagnosis of coronary artery disease. Evaluation of the performed test was carried out with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT). METHODS: Blood was obtained from peripheral veins of 53 patients (37 men and 16 women, mean age 49 +/- 11 years). Plasma hydrogen peroxide levels were estimated by spectrophotometric methods: immediately before a dipyridamole challenge and after drug infusion. RESULTS: Hydrogen peroxide plasma levels in patients with a negative SPECT test were 23.5 +/- 3.0 mumol/l (mean +/- SEM) and 21.0 +/- 2.9 after the dipyridamole infusion (P = 0.474). Plasma concentrations of hydrogen peroxide in patients with a positive SPECT test were 30.5 +/- 4.6 and increased after dipyridamole challenge to 50.3 +/- 5.4 (P = 0.004). Further analysis revealed that the observed difference cannot be attributed to previous history of myocardial infarction. CONCLUSIONS: Even transient myocardial ischemia can generate toxic oxygen derivatives. Evaluation of plasma levels of hydrogen peroxide may be of clinical relevance in patients with suspected coronary artery disease.

[Actions of new iminium compounds against bacteria and fungi. 30. 3-alkoxymethyl-1-hexyl-, 3-alkylthiomethyl-1-hexyl-, 3-alkoxymethyl-1-octyl- and 3-alkylthiomethyl-1-octylbenzimidazolium chlorides]. / Wirkung neuer Iminiumverbindungen gegen Bakterien und Pilze, 30. Mitt.: 3-Alkoxymethyl-1-hexyl-,3-Alkylthiomethyl-1-hexyl-, 3-Alkoxymethyl-1-oktyl- und 3-Alkylthiomethyl-1-oktylbenzimidazoliumchloride.

Syntheses and antimicrobial activity of the title compounds are described. They were obtained by reaction of 1-hexyl- or 1-octylbenzimidazol with chloromethylalkyl ether or chloromethylalkyl sulfide. The antibacterial properties were tested on 13 strains of bacteria and fungi. The best antibacterial activity was exhibited by chlorides with octylthiomethyl and decyloxymethyl groups.

An alternative to dental floss in a personal dental hygiene program.

The concept of gingival massage on maintaining the health of the gingiva may be of value as an adjunct in the periodontal maintenance phase of treatment. This study compared dental floss to a test product, a massage device, in a randomized population of 20 male and female subjects. Clinical measurements were taken at baseline, week 3, and week 6. Patients were instructed to brush twice daily using their normal hygiene methods and to use the assigned product once daily. Plaque index (PI), bleeding index (BI) and pocket probing depths did improve in both the control and the test groups, but the differences did not favor either group over the other. The gingival index (GI) did, however, significantly decrease in the massage group, suggesting that this product may not only be an alternative to dental floss, but may provide added benefits from gingival massaging.

Treatment of hairy cell leukemia patients with 2-chloro-2'-deoxyadenosine (2-CdA).

A preliminary study of six hairy cell leukemia patients treated with one course of 2-chloro-2'-deoxyadenosine (2-CdA) is presented. 2-CdA was administered 0.1 mg/kg/daily by intravenous infusion over 7 days. Two patients achieved CR and four PR.