Catheter-related bloodstream infections in infants hospitalized in neonatal intensive care units: a single center study

Sepsis in neonates carries a high morbidity and mortality rate and is among the most feared complications in the neonatal intensive care unit (NICU). Catheter-related bloodstream infections (CRBSI) are a common etiology of late-onset sepsis. The aim of this study was to compare risk factors and characteristics between patients according to the type of catheter that was utilized and according to birth weight classification. The study included 51 newborns with confirmed CRBSI, which were hospitalized in our level 3 NICU between January 2017 and December 2018. The study population was stratified according to the type of venous catheter utilized (peripherally inserted central catheter, central venous catheter (CVC), and peripheral venous catheter). Infants with low birth weight and those who required prolonged parenteral nutrition were most likely to develop CRBSI in our study group. The type of venous catheter was not associated with blood culture results. Also, infants with a birth weight of < 1500 g and > 1500 g did not differ in sepsis etiology. Further research is required to assess venous catheters relative risk of causing sepsis and if the outcome can be traced back specifically to catheter type or patient characteristics.

A study of the symmetry of roots and root canal morphology in mandibular anterior teeth using cone-beam computed tomographic imaging in a Polish population

BACKGROUND

The purpose of the study was to analyse mandibular anterior teeth in a Polish population and determine the symmetry of root and root canal morphology between the right and left side using cone-beam computed tomography (CBCT) scanning.

MATERIALS AND METHODS

From 111 CBCT examinations, 303 pairs of equivalent mandibular anterior teeth were analysed on the right and left sides to evaluate symmetry. Axial, sagittal, and cross-sectional slices with a thickness of 0.2-0.25 mm were used. The number of root canals and their internal patterns were classified following Vertucci's criteria.

RESULTS

All incisors in this study had 1 root. Canines usually had a single root and much less often had 2 roots. Type I and III root canal configurations were found most often, while type V and II configurations were less frequent. Significant compatibility between the left and right side was observed in all evaluated variables. Incisors had the highest symmetry with regard to the number of roots (100%). Second canals were observed more often in males than females, but only the results in lateral incisors were significant.

CONCLUSIONS

This study provides supplemental information for dentists and should help them to better predict the morphology of mandibular anterior teeth in complicated cases in the Polish population. Symmetry was observed in roots and root canal morphology in all examined parameters.

How Do the Etching Mode and Thermomechanical Loading Influence the Marginal Integrity of Universal Adhesives?

OBJECTIVE

This study evaluated the effect of etching mode and thermomechanical loading on universal adhesives.

METHODS AND MATERIALS

Two universal adhesives, Peak Universal and Adhese Universal, were used in two etching modes as the experimental groups: Peak Universal etch-and-rinse (PER), Peak Universal self-etch (PSE), Adhese Universal etch-and-rinse (AER), and Adhese Universal self-etch (ASE). Two adhesives considered gold standards were used as control groups: OptiBond FL (OER) was used as a control group for the etch-and-rinse (ER) mode, and Clearfil SE Bond (CSE) was used as a control group for the self-etch (SE) mode. Standardized class V cavities were created on the buccal and lingual surface in 30 extracted caries-free human third molars. Each adhesive and resin composite was applied according to the manufacturer's instructions. The specimens were subjected to thermomechanical loading (TML) immediately after the fillings were placed. Before and after TML, replicas and photographs of the fillings were performed and evaluated quantitatively and qualitatively. The Mann-Whitney U-test or Kruskal-Wallis test was used for quantitative analyses, and Fisher exact test was used for qualitative analysis.

RESULTS

Adhese Universal achieved a significantly higher percentage of continuous margin in the enamel than Peak Universal for the two types of etching both before and after TML (except for the SE group after TML). In dentin, the greatest percentage of continuous margin was achieved for Adhese Universal in the ER group (100%) before TML and for both universal adhesives in the SE groups (61%) after TML. For both etching modes and both time points, Adhese Universal had a greater percentage of continuous margin than Peak Universal for the whole margin. For the ER approach, significant differences were observed both before and after TML, and for the SE approach, significant differences were observed before TML. TML did not cause a significant decrease in the percentage of continuous margin in the enamel, but the results were the opposite in dentin. A qualitative assessment using World Dental Federation criteria did not show statistically significant differences between the groups.

CONCLUSIONS

Scanning electron microscope assessment of marginal integrity showed that the evaluated factors such as etching mode and TML significantly influenced the marginal integrity of the universal adhesives. The replica method shows that laboratory and clinical assessment methods complement each other and give a broader view of marginal integrity.

Comparison of polyphenol content and antioxidant capacity of strawberry fruit from 90 cultivars of Fragaria × ananassa Duch

Strawberry fruit is a valuable resource, rich in vitamins and polyphenolic compounds. These compounds have a broad spectrum of biological activity. The aim of this study was to evaluate the qualitative and quantitative composition of polyphenols in strawberry fruit from 90 cultivars of Fragaria × ananassa Duch. from two growing seasons. Eighty of them were analyzed for the first time (to the best of our knowledge). The identification of polyphenolics and other compounds was performed using UPLC-qTOF-MS/MS. Nine compounds were recorded for the first time in mature strawberry fruit. Antioxidant properties were also determined using DPPH and ABTS methods. Statistical analysis of the results was performed using principal component analysis. Tannins, especially ellagitannins with agrimoniin, as well as the total polyphenols, had the greatest influence on antioxidant activity in the ABTS test. Cultivars characterized by a high content of tannins and high antioxidant capacity were selected.

A fluorescent HTS assay for phosphohydrolases based on nucleoside 5'-fluorophosphates: its application in screening for inhibitors of mRNA decapping scavenger and PDE-I

Several nucleotide-specific phosphohydrolases can cleave P-F bonds in substrate analogues containing a fluorophosphate moiety to release fluoride ions. In this work, by employing a fluoride-sensitive molecular sensor, we harnessed this cleavage reaction to develop a fluorescence assay to screen for phosphohydrolase inhibitors. The assay is rapid, sensitive, and based on simple and synthetically available reagents. The assay was adapted to the high-throughput screening (HTS) format and its utility was demonstrated by screening an 'in-house' library of small nucleotides against two enzymes: DcpS, a metal-independent mRNA decapping pyrophosphatase of the histidine triad (HIT) family; and PDE-I, a divalent cation-dependent nuclease. Our screening results agreed with the known specificities of DcpS and PDE-I, and led to the selection of several inhibitors featuring low-micromolar IC50 values. For DcpS, we also verified the results by using an alternative method with the natural substrate. Notably, the assay presented here is the first fluorescence-based HTS-adaptable assay for DcpS, an established therapeutic target for spinal muscular atrophy. The assay should be useful for phosphohydrolase specificity profiling and inhibitor discovery, particularly in the context of DcpS and other HIT-family enzymes, which play key roles in maintaining cellular functions and have been linked to disease development.

Bayesian QTL analyses using pedigreed families of an outcrossing species, with application to fruit firmness in apple

Proof of concept of Bayesian integrated QTL analyses across pedigree-related families from breeding programs of an outbreeding species. Results include QTL confidence intervals, individuals' genotype probabilities and genomic breeding values. Bayesian QTL linkage mapping approaches offer the flexibility to study multiple full sib families with known pedigrees simultaneously. Such a joint analysis increases the probability of detecting these quantitative trait loci (QTL) and provide insight of the magnitude of QTL across different genetic backgrounds. Here, we present an improved Bayesian multi-QTL pedigree-based approach on an outcrossing species using progenies with different (complex) genetic relationships. Different modeling assumptions were studied in the QTL analyses, i.e., the a priori expected number of QTL varied and polygenic effects were considered. The inferences include number of QTL, additive QTL effect sizes and supporting credible intervals, posterior probabilities of QTL genotypes for all individuals in the dataset, and QTL-based as well as genome-wide breeding values. All these features have been implemented in the FlexQTL(™) software. We analyzed fruit firmness in a large apple dataset that comprised 1,347 individuals forming 27 full sib families and their known ancestral pedigrees, with genotypes for 87 SSR markers on 17 chromosomes. We report strong or positive evidence for 14 QTL for fruit firmness on eight chromosomes, validating our approach as several of these QTL were reported previously, though dispersed over a series of studies based on single mapping populations. Interpretation of linked QTL was possible via individuals' QTL genotypes. The correlation between the genomic breeding values and phenotypes was on average 90 %, but varied with the number of detected QTL in a family. The detailed posterior knowledge on QTL of potential parents is critical for the efficiency of marker-assisted breeding.

Nasal CPAP (Infant Flow) applied at birth in extremely low birth weight newborns

OBJECTIVE

Evaluation of nasal CPAP (Infant Flow) as a ventilatory support, applied at birth in spontaneously breathing, extremely low birth weight newborns (ELBW).

MATERIAL AND METHODS

Retrospective analysis of the clinical course of respiratory distress syndrome (RDS) in 97 ELBW, who needed ventilatory support. In all patients the noninvasive ventilatory support was introduced within the first minute of life.

RESULTS

Among all analyzed newborns, 37.1% of patients were not intubated during hospitalization. Moreover, another 10.3% patients were intubated only due to surfactant administration according to the INSURE method and after 2-3 minutes of invasive ventilation they were switched to n-CPAP. Nearly half (47.4%) of all evaluated ELBW newborns who needed ventilatory support avoided mechanical ventilation. We found the frequency of bronchopulmonary dysplasia in 97 analyzed patients markedly lower when compared to data presented in literature (19% vs 34%; p=0.026).

CONCLUSION

We suggest that starting ventilatory support with the n-CPAP from the first minute of life is a safe and effective strategy in extremely low birth weight infants. It also reduces the costs of treatment, associated with surfactant administration.

Pelvic pain, free fluid in pelvis, and human chorionic gonadotropin serum elevation: recurrence of malignant ovarian germ-cell tumor or early pregnancy?

Conservative treatment of metastatic germ-cell tumor of the ovary does not exclude the possibility of pregnancy in the future. Serum beta-human chorionic gonadotropin (beta-hCG) serves as pregnancy test, and has also been proven to be a useful marker for ovarian germ-cell tumors. This paper is a case report of a 19-year-old patient who was admitted to a district hospital in emergency due to pelvic pain, amenorrhoea, and free fluid in the pelvis. Laboratory tests demonstrated slight increase in beta-hCG serum concentration and transvaginal ultrasound (TVUS) showed no evidence of gestational sac in the uterus. At the age of 14, the patient was diagnosed with malignant germ-cell tumor of the left ovary in FIGO Stage IV and was treated with four courses of chemotherapy according to TGM-95 protocol with etoposide, ifosfamide, and cisplatin, followed by conservative surgery and adjuvant two courses of cytostatics. The initial diagnosis was recurrence of ovarian malignancy and the patient was referred to an oncology center. Wait-and-see approach and repeated ultrasound examination confirmed a normal intrauterine pregnancy which concluded with the delivery of a healthy newborn through cesarean section.

Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water

Objectives

The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water.

Materials and methods

The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated.

Results

Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite.

Conclusion

The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components.

Clinical relevance

To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

Brillouin study of photopolymerization process of two-monomer systems

The results of Brillouin scattering investigations of two-component system: 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane/polyethylene glycol methacrylate (bis-GMA/PEGMM) containing 0, 30, 50, 70, 85 and 100 mol% of PEGMM are presented. For the first time the Brillouin spectroscopy was used to monitor the progress of the polymerization process. The polymerization was initiated by ultraviolet radiation (λ=365 nm), at temperature 20°C and 40°C. Some of the physical parameters characteristic for this system such as velocity V, adiabatic compressibility β(ad) and attenuation coefficient α of the acoustic waves have been estimated from Brillouin spectra as a functions of the polymerization time. The obtained results have been discussed in terms of changes of the elastic properties of the two-component system occurring during polymerization process and their dependence on bis-GMA/PEGMM system composition.

Phenotype of dendritic cells generated from peripheral blood monocytes of patients with ovarian cancer

OBJECTIVES

The aim of our study was to generate dendritic cells (DCs) from peripheral blood monocytes (PBMC) of patients suffering from ovarian cancer.

MATERIALS AND METHODS

Immature DCs were generated from PBMC cultured in RPMI 1640 medium with 2% human serum albumin (HSA), supplemented with recombinant human (rh) granulocyte macrophage colony stimulating factor (GM-CSF) and rh interleukin (IL)-4. After 5 days of culture, DC maturation was induced by the addition of an ovarian cancer cell line (CAOV3) lysate and after 6 days of rh tumor necrosis factor (TNF)-α for a further 2 days. The phenotype of the generated cells was assessed by flow cytometry for the expressions of human leukocyte antigen (HLA)-DR, costimulatory molecules (e.g., CD86, CD80), CD83, CD1a, and CD14. PBMC cultured in 2% HSA without rhIL-4, rhGM-CSF, rh-TNF-α, or tumor cell lysate formed the control group.

RESULTS

The 2.41% (interquartile range, 1.51%-3.52%) of CD45+/CD14+ cells in cultures with rhIL-4, rhGM-CSF, rhTNF-α and tumor cell lysate was significantly lower than in the control group (31.10%; interquartile range, 11.11%-64.06%). Cultures with rhIL-4, rhGM-CSF, rhTNF-α, and tumor cell lysate showed a higher percentage (19.96%; interquartile range, 9.30%-24.42%) of fully mature CD83+/CD1a-/HLA-DR+ DCs compared with control culture (6.02%; interquartile range, 3.01%-7.37%). There was no significant difference in the expression of the immature DC marker (CD1a) between the cultures. The expression of co-stimulatory markers (CD80, CD86, HLA-DR) was greater (24.29%; interquartile range, 18.68%-33.95%) on DCs from cultures with rhIL-4, rhGM-CSF, TNF-α, and tumor cell lysate versus controls (4.93%; interquartile range, 2.67%-9.09%).

CONCLUSION

Our data demonstrated that immature and mature DCs can be generated from adherent human PBMC from ovarian cancer patients cultured with rhIL-4, rhGM-CSF, rhTNF-α, and tumor cell lysates.

Is it about the self or the significance? An fMRI study of self-name recognition

Our own name, due to its high social relevance, is supposed to have a unique status in our information processing. However, demonstrating this phenomenon empirically proves difficult as famous and unknown names, to which self-name is often compared in the studies, may differ from self-name not only in terms of the 'me vs. not-me' distinction, but also as regards their emotional content and frequency of occurrence in everyday life. In this fMRI study, apart from famous and unknown names we used the names of the most important persons in our subjects' lives. When compared to famous or unknown names recognition, self-name recognition was associated with robust activations in widely distributed bilateral network including fronto-temporal, limbic and subcortical structures, however, when compared to significant other's name, the activations were present specifically in the right inferior frontal gyrus. In addition, the significant other's name produced a similar pattern of activations to the one activated by self-name. These results suggest that the differences between own and other's name processing may rather be quantitative than qualitative in nature.

Acute pulmonary embolism registry in the Małopolska region - clinical course

BACKGROUND

Acute pulmonary embolism (APE) is a life-threatening disease. Mortality in APE still remains very high in spite of progress in diagnostic tools. Mortality rate is about 30% in patients with unrecognised APE. APE is one of the main causes of in-hospital mortality.

AIM

To asses management of patients with APE in the Małopolska region.

METHODS

This registry consists of 205 consecutive patients who were hospitalised in 6 cardiology departments between 1 January 2005 and 30 September 2007, with the mean age of 65.1 +/- 15.3 years (124 females and 81 males). Mean hospitalisation duration 14.6 days (1-52 days).

RESULTS

During hospitalisation 23 (11.2%) patients died. Complications (death, cardiogenic shock, cardiac arrest, use of catecholamines, respiratory therapy and ventilation) during in-hospital stay were observed in 57 (27.8%) patients. Fifty-three patients were haemodynamically unstable (cardiogenic shock or hypotension). The troponin I or T level was assessed in 147 (71.7%) patients and in 50 (34.0%) was positive. In patients with positive troponin we observed 11 (22.0%) deaths, while in patients with normal troponin T or I level 6 (6.2%) deaths occurred. In patients with normal blood pressure we observed a significant difference in mortality in patients with elevated vs. normal troponin level (14.3 vs. 2.5%, p = 0.02). Thrombolytic therapy was used in 20 (9.8%) patients. In patients treated with thrombolytic therapy 9 (45%) deaths were observed. We divided patients according to the ESC 2008 guidelines risk stratification. The 'non-high risk' group consisted of 152 (74.1%) patients, and mortality was 3.9%. The 'high-risk' group consisted of 53 (26.8%) patients. The 'non-high risk' group was divided into the following subgroups: 1. moderate-high (with 2 risk factors: both RV dysfunction and positive injury markers) mortality - 8.1%; 2. moderate subgroup with one risk factor, mortality - 3.6%; 3. low risk - no risk factors - 0% mortality.

CONCLUSIONS

1. In our registry mortality rate in patients with APE was 11%. 2. In about 30% of patients APE was under mask of acute coronary syndrome or syncope, 34% of patients had elevated troponin level, and 30% of patients had complication during hospitalisation. 3. In patients treated with thrombolytics mortality rate was 45%. 4. Reperfusion strategy (trombolysis or embolectomy) in the high risk group was used in only 41% of patients. 5. Elevated troponin level in normotensive patient was associated with 4-fold times higher risk of death. 6. New risk stratification according to the ESC guidelines 2008 correctly predicts prognosis in everyday clinical practise.

Influence of pleural macrophages on proliferative activity and apoptosis regulating proteins of malignant cells

Malignant tumors contain numerous macrophages as a major component of the leukocytic infiltrate. Only few studies have evaluated the interaction between products secreted by macrophages and tumor cells. Our objective was to study soluble factors produced by pleural macrophages. We sampled pleural effusions from patients with cancer and used human tumor cell lines as targets. Pleural macrophages were cultured and the supernatants were used as a conditioned medium for cultures of human cell lines A549, HT29, HCT116, SW620, MCF7, MDA-MB231, JURKAT, and HL60. We investigated apoptosis, proliferative activity, and expression of apoptosis regulating proteins Fas, Bcl2, Caspase-3, and survivin of malignant cells cultured in the conditioned medium. Our findings raise the possibility that macrophages from malignant pleural effusions can act as a factor inhibiting apoptosis of malignant cells.

Concentration of matrix metalloproteinase-9 in serum of patients with chronic obstructive pulmonary disease and a degree of airway obstruction and disease progression

Chronic obstructive pulmonary disease (COPD) is chronic inflammation leading to irreversible airway obstruction. Previous studies showed increased metalloproteinases (MMP) level, especially MMP-9, as a sign of local inflammation. Up-to-date, only a few studies estimated the MMP-9 serum concentration in COPD with respect to correlation with systemic inflammation. The aim of the present study was to estimate the MMP-9 serum concentration in COPD and to evaluate the correlation between MMP-9 and a degree of airway obstruction in COPD. Twenty three COPD patients and 23 healthy controls were enrolled. In both groups spirometry was performed. MMP-9 concentration in sera taken from both groups was studied using ELISA. We found that COPD patients had increased serum MMP-9 concentration compared with the control group (P=0.0005). In the COPD group, the MMP-9 levels were negatively correlated with FEV1 (P=0.01) and FEV1/FVC (P=0.0002). In conclusion, the results suggest that MMP-9 plays an important role in systemic inflammation in COPD. Higher MMP-9 serum concentration is connected with higher airway obstruction and disease progression.

Challenges in care of adult CF patients--the specialist cystic fibrosis team

Cystic fibrosis (CF) is the most common life-limiting, autosomal, recessive genetic disorder. The gene which is responsible for the symptoms of this disease is located on the long arm of chromosome 7 and encodes the protein called Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), an apical chloride channel in epithelial cells. CF is a "multi-system" disease. It affects many parts of the body and it has a varied clinical expression. All patients with CF should have access to specialist services and the treatment must be comprehensive and multidisciplinary. The multidisciplinary team approach is important when trying to optimize care given to the patient and their family. The cystic fibrosis team may include personnel from the following specialist areas: medical, nursing, physiotherapy, dietetics, psychological, social/supportive. Close coordination is vital. Ideally, 'all members of the team' should have had CF care-related training. The specialist team approach ensures that such specialized multidisciplinary expertise is applied in all aspects of care, better knowledge of individual families, continuity, knowledge of treatment advances and the ability to apply these in daily management. Doubtlessly CF team ensures families a specific point of contact and they know who to talk to. In 1997 The Department of Pulmonology Diseases in Poznań started running a programme for CF adults at our University--the second CF adult centre in Poland. Members of our CF team have experience in the management of adults who have cystic fibrosis. Its members include physicians, nurses, a physiotherpist, a dietitian, a social worker and a psychologist. We must to build the team approach in CF care and use effectively talents of multiprofessional team members as fully as possible to deliver better services to patients.

Sex-related differences in interhemispheric transmission time in the human brain

Many studies on hemispheric specialization for language functions and on morphology of the corpus callosum have revealed stronger lateralization and smaller splenium area in men than in women. We have tested the related prediction that interhemispheric transmission times (IHTTs) of verbal information differ in the two sexes using event-related potentials (ERPs) for determining IHTTs in male and female subjects. The IHTTs were estimated as latency differences between early components of ERPs, recorded in response to words from symmetrical sites of directly and indirectly stimulated hemisphere, i.e. the hemisphere contralateral and ipsilateral to the visual hemifield of stimulus presentation. In women, IHTTs were similar for the left-to-right and right-to-left directions, whereas in men, IHTTs were directionally asymmetrical and were considerably longer for the left-to-right direction.

The differential killing of genes by inversions in prokaryotic genomes

We have elaborated a method which has allowed us to estimate the direction of translocation of orthologs which have changed, during the phylogeny, their positions on chromosome in respect to the leading or lagging role of DNA strands. We have shown that the relative number of translocations which have switched positions of genes from the leading to the lagging DNA strand is lower than the number of translocations which have transferred genes from the lagging strand to the leading strand of prokaryotic genomes. This paradox could be explained by assuming that the stronger mutation pressure and selection after inversion preferentially eliminate genes transferred from the leading to the lagging DNA strand.

[Patterns of cognitive impairment and apolipoprotein genotype in persons with Alzheimer's disease]

The aim of this study was to test the possible relationship between patterns of cognitive deficits--especially impairment of memory processes--and ApoE genotype in patients with AD. Fifty seven right-handed subjects (31 males and 26 females) were tested in this study. The age of subjects ranged from 50 to 79, the education lasted from 11 to 16 years. All subjects were diagnosed as probable AD patients on the basis of DSM IV and NINCDS-ADRDA criteria. Each subject was examined for: 1) ApoE genotype, 2) general level of activity (GDS and MMSE), 3) neuropsychological evaluation of cognitive processes, using full test battery. 37 patients had at least one of ApoE epsilon 4 allele (e2/4, 3 and 4/4) and 20 patients had none of ApoE 4 allele (e 2/3 and 3/3). The group of tested subjects were subdivided into 2 groups. The first group was comprised by 31 patients with 3-rd stage (according to GDS) of mental activity. Twenty six patients with 4-th stage were included into the second group. Those subgroups did not significantly differ if age, education, gender or ApoE allele were considered. Experimental data were normalized and then analyzed using a statistical package SPSS/PC+. The analysis of variance showed that the type of test, stage of disease and two-way interaction ApoE x type of test were highly significant (P < 0.0001). Some results were obvious and not surprising (e.g. that results of patients with 4-th stage were much worse than the results of patients with stage 3-rd). It turned out that the best results were obtained by our patients in naming tests, the worst--in learning test with distraction. Patients with ApoE epsilon 4 performed better than patients with none ApoE epsilon 4 in the Rey's test, in the similarity test and in the test which required repeating numbers starting from the last one. The differences between the subgroups of patients with different ApoE alleles were confirmed by different distributions of correlations. All statistical analyses were repeated for more homogenous group of patients (only with stage 3-rd). The pattern of results resembled the previous one (i.e. better performance in the same tests) with one exception: additionally, in delayed recall test patients with none ApoE epsilon 4 performed much better that ApoE epsilon 4. Our results showed that some cognitive processes depended on ApoE genotype. Patients with none ApoE epsilon 4 genotype had less severe deficits in delayed recall of new information. On the other hand, working memory appeared to be less affected in patients with ApoE epsilon 4 genotype. Independent of genotype, both group showed similar impairment of learning ability without deficits in remote memory.

Psychosomatic reactions to a stressful environment and an attempt at pharmacological modification

BACKGROUND

Extreme environmental conditions significantly influence the functioning of the human organism and trigger distinct stress reactions. In our study we attempted to create an experimental model of complex stress conditions.

MATERIAL AND METHODS

Healthy male volunteers were isolated, deprived of food and sleep, and exposed to extreme temperatures for 5 consecutive days. Physical fitness and selected somatic parameters and biochemical stress markers were measured in the tested subjects. In addition, changes in behavior and mental status were assessed by means of a set of psychological tests. Finally, the effects of pharmacological modification (administration of clobazam and tramadol) on psychosomatic stress reactions were tested.

CONCLUSIONS

The results indicate that our experimental stress conditions slightly altered the mental functions of the subjects, increased their anxiety level, hampered their physical efficiency, and led to weight loss. The administration of the drugs beneficially influenced the subjects' memory and physical efficiency.

Neutrophils promote the release of alpha-6-fucosyltransferase from blood platelets through the action of cathepsin G and elastase

Human blood platelets release alpha-6-fucosyltransferase during coagulation of blood or after stimulation with thrombin or other agonists that cause platelet activation (Antoniewicz et al., FEBS Lett. 244 (1989) 388-390). However, in the absence of neutrophils the thrombin-stimulated platelets release only a small fraction of alpha-6-fucosyltransferase activity (Kościelak et al., Acta Biochim. Polon. 42 (1995) 35-40). We show that the effect of neutrophils is reproduced by cathepsin G or (less efficiently) by elastase, the two enzymes that are released by neutrophils during coagulation of blood. We have also localized alpha-6-fucosyltransferase to membrane and alpha-granule fractions of platelets that had been disrupted by nitrogen cavitation. It is concluded that thrombin-activated neutrophils release cathepsin G and elastase that promote degranulation of platelets and hence the secretion of alpha-6-fucosyltransferase.

Subjective contour illusion: sex-related effect of unilateral brain damage

The aim of the study was to investigate the effect of unilateral brain lesions on the perception of subjective contours. Brain damage resulted in a reduced ability to perceive the illusion. The effect, however, was hemisphere and sex dependent. In women an illusion decrement due to either the left or right hemisphere damage was observed, while in men only right hemisphere damage caused a decrement. No specific effect of intrahemispheric localisation of lesion was found. We conclude that mechanisms contributing to subjective contour perception are right hemisphere dependent in males whereas in females they are bilaterally represented.

Evolution rates of genes on leading and lagging DNA strands

One of the main causes of bacterial chromosome asymmetry is replication-associated mutational pressure. Different rates of nucleotide substitution accumulation on leading and lagging strands implicate qualitative and quantitative differences in the accumulation of mutations in protein coding sequences lying on different DNA strands. We show that the divergence rate of orthologs situated on leading strands is lower than the divergence rate of those situated on lagging strands. The ratio of the mutation accumulation rate for sequences lying on lagging strands to that of sequences lying on leading strands is rather stable and time-independent. The divergence rate of sequences which changed their positions, with respect to the direction of replication fork movement, is not stable-sequences which have recently changed their positions are the most prone to mutation accumulation. This effect may influence estimations of evolutionary distances between species and the topology of phylogenetic trees.

Effect of genotype on selected clinical features of Polish cystic fibrosis adults

Cystic fibrosis (CF), the most common autosomal recessive disorder of Caucasians, is caused by the mutations in the gene encoding CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) protein. Until now, approximately 1000 mutations of the CFTR gene have been described. The genotype-phenotype relationships in CF are still not completely understood. This study was undertaken in an attempt to characterise the distribution of CFTR mutations and their effect on selected clinical parameters in a group of Polish CF adults. A total number of 38 adult CF patients (mean age 21.6 +/- 6.8); 18 females & 20 males were enrolled in the study. The CFTR gene identification was conducted with the use of PCR & InnoLipa-CF set. The assessed clinical parameters included: age at diagnosis, age, lung function test, X-ray scored in Brasfield score, weight & height. We found that: (1) the genotypes of the studied population were unevenly distributed (65.8%- genotype deltaF508/M), (2) a high percentage of 3849+10kbC-->T was noted, (3) patients homozygous for the deltaF508 mutation were diagnosed significantly earlier and had a lower body mass index, (4) no differences were observed in the patients' length of life or the progression of lung disease.

CONCLUSIONS

1. In comparison to other populations, Polish adult CF patients display a relatively higher frequency of mild mutations. 2. Late diagnosis of CF in the studied group may be partially caused by a high percentage of CFTR mutations connected with the mild course of the disease that are difficult to identify. 3. Cystic fibrosis should be more commonly taken into consideration in the differential diagnosis in adult patients with milder symptoms.

DNA asymmetry and the replicational mutational pressure

The mode of replication and organisation of bacterial genomes impose asymmetry on their nucleotide composition. The asymmetry is seen in coding and non-coding sequences and is reflected in the amino acid composition of proteins. The mechanisms generating asymmetry include: unequal mutation rates connected with replication and transcription, selection forces positioning genes and signal sequences nonrandomly in the genome, and protein coding constraints on coding sequences. There are different methods of visualising and measuring the asymmetry. Some of them can assess the contribution of individual mechanisms to the observed asymmetry and those have been described in greater detail. Asymmetric mutational and selection pressures differentiate the rates of evolution of genes on leading and lagging strands. The genes relocated to the opposite strand have to adapt to a different mutational pressure or are eliminated. Translocations from leading to lagging strands are more often selected against than from lagging to leading strands. Comparison of intergenic sequences that have lost the coding function to the original genes enables finding the frequencies of the twelve substitution rates in sequences free from selection. In the absence of selection, the half-time of substitution of a given type of nucleotide is linearly correlated with the fraction of that nucleotide in the sequence.

[Comparative studies of two different systems for bonding composites with tissue of the tooth]

The objective of studies was the clinical evaluation concerning the influence of the bonding systems Syntac and Gluma exerted on the quality of compositive fillings in various types of defects in humans, in comparison to fillings, in which Compa Bond resin was used. The question was studied to answer whether there were any significant differences in respect of the assessed parameters between fillings by Syntac system and the fillings by Gluma system with preservation and marginal adaptation being taken into consideration. The studies were performed on 98 patients of both sexes, therein 56 women and 42 men. The assessment included 248 classified fillings, namely: 82 of Tetric material, 78 of Pekalux material and 88 of C-Fill MH and C-Molar materials. The fillings were estimated directly after placement, as well as after 6, 12, and 24 months, under artificial light by making use of dental mirror, a probe and an optic device (magnifying glass of fivefold magnification), on the basis of own card of investigations for compositive fillings. The dental pulp reaction to thermic simuli and faradic current was also taken into account. Fillings classified by grades 0 degree and 1 degree were defined as clinically acceptable, while 2 degrees and 3 degrees as clinically unacceptable. The statistical analysis was carried out by means of Chi 2 test. The number of Tetric and Pekalux materials fillings lost after 24 months of studies was substantially lower than the number of lost fillings made of C-Fill MH and C-Molar materials. The loss only concerned defects of non-carious origin, namely wedge shaped defects and pathological attrition of teeth (Tab. 1 and Tab. 2). The fillings by Syntac system are characterized by better marginal adaptation as compared with fillings, wherein the Gluma system was applied, however, no statistically significant differences between these groups were disclosed (Tab. 3). Significant differences were found to appear between the groups, of fillings, in which use was made of bonding systems Syntac and Gluma on the one hand, and the fillings set up by Compa Bond resin on the other. Assessing the colour, smoothness of surface and the anatomical shape of the fillings after 24 months no essential differences between the studied material groups were revealed. Secondary caries and post-procedural sensitivity involved only the cases, in which Compa Bond resin and C-Fill MH material were employed. After 24 months of studies the percentage of clinically acceptable fillings claimed to be as follows: Tetric 93.51%, Pekalux 91.55%, C-Fill MH and C-Molar 75.36%. Thus, it was disclosed that there were significantly more clinically acceptable fillings made of Tetric and Pekalux materials than of C-Fill MH and C-Molar materials. The Syntac and Gluma systems exerted significant influence on better preservation and marginal adaptation of fillings mainly in defects of non carious origin, in comparison to the fillings in which the conventional Compa Bond resin was being used. In cases, wherein Syntac and Gluma systems were applied, no post-procedural hypersensitivity was recorded. This ailment was evidenced in 4.5% of cases after implementing Compa Bond resin.

Eye position-sensitive units in hippocampal formation and in inferotemporal cortex of the macaque monkey

The activity of 330 hippocampal and inferotemporal cells was recorded while seated monkeys with fixed heads worked in a visual discrimination task. Monkeys had to move their eyes to one of five different positions to maintain gaze on an image. The image was then extinguished and the monkeys maintained a fixed gaze on the target position in darkness to obtain a reward. The five positions of image presentation were on a horizontal line, consisting of a centre position and lateral positions which were 10 and 20 degrees right and left of it. Twenty-two per cent of single units recorded from the hippocampus showed statistically significant sensitivity to target position in complete darkness. A similar fraction (23%) was significantly affected by target position in the light. Position sensitivity was also found among cells recorded from the inferotemporal cortex. Eye position significantly influenced the activity of 19% of inferotemporal units in darkness and 28% of inferotemporal units in the light. Interestingly, the populations of cells showing position effect in the light and in darkness were independent.

Sex related effect of unilateral brain lesions on the perception of the Mueller-Lyer illusion

The aim of this study was to investigate the effect of unilateral brain lesions on Mueller-Lyer (M-L) illusion in the two sexes. Patients with left hemisphere (LH) and right hemisphere (RH) damage and control subjects participated in the experiment. They inspected series of M-L patterns in which the shaft with out-going fins was gradually shortened until it induced a perception opposite to the original illusion, that is, the shaft with out-going fins appeared to be shorter than the shaft with in-going fins. The subjects' task was to decide, on each trial, whether the variable shaft was longer or shorter than the other one. The point where the judgements changed from one category to the other was established using the Spearman distribution method for determining psychophysical thresholds, and was considered the measure of the strength of the illusion. The higher the value of the threshold, the stronger the illusion. Our results showed sex-related hemispheric asymmetry in subjects' susceptibility to the M-L illusion, i.e., both LH and RH lesions in females, but only RH lesions in males resulted in an increase of the strength of illusion. Moreover, males with LH lesion as well as controls partially corrected the illusory perception with practice, while both LH and RH damaged females and RH damaged males did not show this learning effect.

In vivo protein interactions within the Escherichia coli DNA polymerase III core

The mechanisms that control the fidelity of DNA replication are being investigated by a number of approaches, including detailed kinetic and structural studies. Important tools in these studies are mutant versions of DNA polymerases that affect the fidelity of DNA replication. It has been suggested that proper interactions within the core of DNA polymerase III (Pol III) of Escherichia coli could be essential for maintaining the optimal fidelity of DNA replication (H. Maki and A. Kornberg, Proc. Natl. Acad. Sci. USA 84:4389-4392, 1987). We have been particularly interested in elucidating the physiological role of the interactions between the DnaE (alpha subunit [possessing DNA polymerase activity]) and DnaQ (epsilon subunit [possessing 3'-->5' exonucleolytic proofreading activity]) proteins. In an attempt to achieve this goal, we have used the Saccharomyces cerevisiae two-hybrid system to analyze specific in vivo protein interactions. In this report, we demonstrate interactions between the DnaE and DnaQ proteins and between the DnaQ and HolE (theta subunit) proteins. We also tested the interactions of the wild-type DnaE and HolE proteins with three well-known mutant forms of DnaQ (MutD5, DnaQ926, and DnaQ49), each of which leads to a strong mutator phenotype. Our results show that the mutD5 and dnaQ926 mutations do not affect the epsilon subunit-alpha subunit and epsilon subunit-theta subunit interactions. However, the dnaQ49 mutation greatly reduces the strength of interaction of the epsilon subunit with both the alpha and the theta subunits. Thus, the mutator phenotype of dnaQ49 may be the result of an altered conformation of the epsilon protein, which leads to altered interactions within the Pol III core.

Activity linked to externally cued saccades in single units recorded from hippocampal, parahippocampal, and inferotemporal areas of macaques

We studied whether target-directed, externally commanded saccadic eye movements (saccades) induced activity in single units in inferotemporal cortex, the hippocampal formation, and parahippocampal gyrus. The monkeys first were required to fix their gaze on a small cross presented to the left or right of center on the monitor screen. The cross was extinguished, and a random 600-1,000 ms thereafter, a small dot was presented for 200 ms. The dot was located either 10 degrees above, below, right, or left of the position on which the fixation cross had been. The monkey made a saccadic eye movement to this dot (in darkness). The neuronal activity around this goal-directed saccade was analyzed. In addition, control conditions were imposed systematically in which similar dots were presented, but the monkey's task was to withhold the saccade. We recorded 290 units from two monkeys. From this group, 134 met two criteria, they did not show visual response in control trials and they had spike rates >2 Hz. These were analyzed further; 53% (71/134) showed modulation related to the target directed saccade, and 29% (39/134) showed saccadic modulation during spontaneous eye movements. These two groups were correlated only weakly. Of the units with significant saccadic modulation, 17% (12/71) showed significant directional selectivity, and 13% (9/71) showed significant position selectivity (P < 0.01). At a lower criterion (P < 0.05), almost one-half (33/71) showed one or the other spatial selectivity. Primates use saccades to acquire visual information. The appearance of strong saccadic modulation in brain structures previously characterized as mnemonic suggests the possibility that the mnemonic circuitry uses an extraretinal signal linked to saccades to control visual memory processes, e.g., synchronizing mnemonic processes to the pulsatile visual data inflow.

Visual-spatial-frequency model of cerebral asymmetry: a critical survey of behavioral and electrophysiological studies

In this article, the authors present a review of research on the role of the 2 hemispheres in processing spatial frequencies. J. Sergent (1982a) postulated that the hemispheres differ in their sensitivity to frequency characteristics of the sensory outputs on which cognitive processes are performed. Specifically, she proposed that the right hemisphere displays greater efficiency than the left hemisphere in processing low-spatial-frequency content of a visual image, whereas the left hemisphere is better equipped than the right to deal with high frequencies. The authors present an extensive review of behavioral and electrophysiological studies whose researchers tried to verify Sergent's hypothesis and offer its reformulation, taking into account the findings that have accumulated in the last 10 years.

Specific in vivo protein-protein interactions between Escherichia coli SOS mutagenesis proteins

One of the components of the RecA-LexA-controlled SOS response in Escherichia coli cells is an inducible error-prone DNA replication pathway that results in a substantial increase in the mutation rate. It is believed that error-prone DNA synthesis is performed by a multiprotein complex that is formed by UmuC, UmuD', RecA, and probably DNA polymerase III holoenzyme. It is postulated that the formation of such a complex requires specific interactions between these proteins. We have analyzed the specific protein-protein interactions between UmuC, UmuD, and UmuD' fusion proteins, using a Saccharomyces cerevisiae two-hybrid system. In agreement with previous in vitro data, we have shown that UmuD and UmuD' are able to form both homodimers (UmuD-UmuD and UmuD'-UmuD') and a heterodimer (UmuD-UmuD'). Our data show that UmuC fusion protein is capable of interacting exclusively with UmuD' and not with UmuD. Thus, posttranslational processing of UmuD into UmuD' is a critical step in SOS mutagenesis, enabling only the latter protein to interact with UmuC. Our data seem to indicate that the integrity of the entire UmuC sequence is essential for UmuC-UmuD' heterotypic interaction. Finally, in our studies, we used three different UmuC mutant proteins: UmuC25, UmuC36, and UmuC104. We have found that UmuC25 and UmuC36 are not capable of associating with UmuD'. In contrast, UmuC104 protein interacts with UmuD' protein with an efficiency identical to that of the wild-type protein. We postulate that UmuC104 protein might be defective in interaction with another, unknown protein essential for the SOS mutagenesis pathway.

Interhemispheric transmission of information and functional asymmetry of the human brain

The study investigated directional differences in interhemispheric transmission time using the VEPs method. Specifically we were interested in whether there exists an asymmetry in the transmission of information to and from the hemisphere specialized in its processing. Two type of stimuli, specific for the left and right hemisphere, were presented in the left and right visual fields. The latency differences between visual evoked potential components registered in the hemispheres ipsilateral and contralateral to the stimulated hemifield were compared. Interhemispheric transmission time was shorter when the information was transferred from the hemisphere non-specialized for its processing to the specialized one than in the opposite direction. The results suggest the existence of a physiological mechanism that ensures fast transmission of information to that hemisphere which is more efficient in its processing.

The antimutagenic effect of a truncated epsilon subunit of DNA polymerase III in Escherichia coli cells irradiated with UV light

It has previously been suggested that inhibition of the proofreading 3'-5' exonuclease activity of DNA polymerase may play an important role in generation of UV-induced mutations in Escherichia coli. Our previous work showing that overproduction of epsilon, the proofreading subunit of DNA polymerase III, counteracts the SOS mutagenic response of E. coli seemed to be consistent with this hypothesis. To explore further the nature of the antimutagenic effect of epsilon we constructed plasmid pMK17, which encodes only two of the three highly conserved segments of epsilon--ExoI and ExoII; the third segment, ExoIII, which is essential for 3'-5' exonuclease activity, is deleted. We show that at 40 degrees C, overproduction of the truncated epsilon subunit significantly delays production of M13 phage, suggesting that the protein retains its capacity to bind to DNA. On the other hand, the presence of pMK17 in a trpE65 strain growing at 40 degrees C causes a 10-fold decrease in the frequency of UV-induced Trp+ mutations. This antimutagenic effect of the truncated epsilon is effectively relieved by excess UmuD,C proteins. We also show that the presence of plasmid pIP21, which contains the dnaQ49 allele encoding an epsilon subunit that is defective in proofreading activity, almost completely prevents generation of UV-induced mutations in the trpE65 strain. We propose that the DNA binding ability of free epsilon, rather than its 3'-5' exonuclease activity, affects processing of premutagenic UV-induced lesions, possibly by interfering with the interaction between the UmuC-UmuD'-RecA complex and Pol III holoenzyme. This interaction is probably a necessary condition for translesion synthesis.

Different UmuC requirements for generation of different kinds of UV-induced mutations in Escherichia coli

An Escherichia coli strain bearing the dnaQ49 mutation, which results in a defective epsilon subunit of DNA polymerase III, and carrying the lexA71 mutation, which causes derepression of the SOS regulon, is totally unable to maintain high-copy-number plasmids containing the umuDC operon. The strain is also unable to maintain the pAN4 plasmid containing a partial deletion of the umuD gene but retaining the wild-type umuC gene. These results suggest that a high cellular level of UmuC is exceptionally harmful to the defective DNA polymerase III of the dnaQ49 mutant. We have used this finding as a basis for selection of new plasmid umuC mutants. The properties of two such mutants, bearing the umuC61 or umuC95 mutation, are described in detail. In the umuC122::Tn5 strain harbouring the mutant plasmids, UV-induced mutagenesis is severely decreased compared to that observed with the parental umuDC+ plasmid. Interestingly, while the frequency of UV-induced GC-->AT transitions is greatly reduced, the frequency of AT-->TA transversions is not affected. Both mutant plasmids bear frameshift mutations within the same run of seven A residues present in umuC+; in umuC61 the run is shortened to six A whereas in umuC95 is lengthened to eight A. We have found in both umuC61 and umuC95 that translation is partially restored to the proper reading frame. We propose that under conditions of limiting amounts of UmuC, the protein preferentially facilitates processing of only some kinds of UV-induced lesions.