A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors.

Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the atmosphere) have the potential to do greater damage than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects. Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave, but owing to lack of observations this is uncertain. Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (±100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.

[Influence of topical fluoridation of glass ionomer cements on inhibitory activity on cariogenic bacteria].

Glass ionomer cements are important options in restorative and preventive dentistry due to their adhesion to the tooth surface and fluoride release, which can decrease the risk of recurrent caries. The aim of this study was to define, in vivo, the influence of the topical use of fluoride gel on dental plaque bacteria growing on the glass ionomer cement. Fifteen patients were included into this study.

[Microorganisms isolated from healthy newborns in the first and third twenty-four hours].

From forty healthy newborns of The Neonatology Ward of H.Jordan Hospital in Lodz, skin and nasal septum-swabs have been sampled immediately after the delivery. Whereas, in the third twenty-four hours of their lives, apart from skin and nasal septum-swabs, it has been sampled also faeces-swabs.

[Prevalence IgG antibodies against Bartonella henselae in children with lymphadenopathy].

Bartonella henselae is a cat scratch disease's etiological agent which is usually manifestated as regional lymphadenopathy. In differential diagnosis of lymphadenopathy infections about etiology B. henselae are rarely taken into consideration.

[Influence of the fluoride releasing dental materials on the bacterial flora of dental plaque].

The assessment of influence of silver-free, fluor releasing dental materials on dental plaque bacteria quantity. 17 patients were included into the study. 51 restorations were placed following manufacturers recommendations.

[Correlation between levels of selected cytokines in cervico-vaginal fluid of women with abnormal vaginal bacterial flora].

The aim of this study was to evaluate the rise of the levels of proinflammatory cytokines - IL-1alpha, IL-1beta, IL-6 and IL-8 in vagina of women with bacterial vaginosis (BV) and if there is any relationship between this levels. One hundred and twenty females between 22nd and 36th week of pregnancy were enrolled in the study. According to the bacterial flora of cervico-vaginal fluid evaluated by Gram stain, all women were divided into three groups.

An in vitro study of affected dentin as a risk factor for the development of secondary caries.

The objective of the study was to investigate the association between the presence of residual caries (inner affected dentin) on the cavity walls of cavity preparations and the further development of secondary caries lesions. Two 2 x 5 x 2 mm cavities, one in the apical portion (A) and one in the cervical portion (C) of the root, were prepared on both the lingual (L) and buccal (B) surfaces of 18 extracted human roots. The apical cavities (AB and AL) were artificially demineralized for 30 min using a decalcifying solution, followed by staining with a caries detector dye and then excavation of irreversibly demineralized dentin, leaving behind a layer of inner carious dentin.

[The correlation between the number of polymorphonuclear leukocytes in human oral cavity and the counts of some bacteria].

The aim of the study was to evaluate the relationship between the number of polymorphonuclear leukocytes (PMNL) and the number of selected bacteria in human oral cavity. Sixty one healthy people (periodontal index of Russel's did not exceed 0.2), aged 22-26 were investigated.

[Impact of Mycoplasma hominis and Ureaplasma urealyticum on the concentration of proinflammatory cytokines in vaginal fluid].

The main aim of this study was to determine impact of Mycoplasma hominis and Ureaplasma urealyticum on the concentrations of selected proinflammatory cytokines in vaginal fluid in pregnant women. The samples were obtained from 120 pregnant women at 22 to 36 weeks gestation. Vaginal fluid were analyzed for the concentrations of IL-1 alpha, IL-1 beta, IL-6 and IL-8 using standard enzyme-linked immunosorbent assay technique (ELISA), and cervical fluid for prevalence of Mycoplasma hominis and Ureaplasma urealyticum.

[Comparison of bacterial flora in the oral cavity of children and adults].

The aim of the study was to assess levels of occurrence and number of aerobic bacteria hemolysing and non-hemolysing, anaerobic bacteria, streptococci hemolysing and non-hemolysing, staphylococci, and bacteria responsible for tooth decay (Streptococcus mutans and Lactobacillus spp.) on oral cavity in children and adults. The results obtained indicate the difference of the level of occurrence of, aerobic bacteria hemolysing and non-hemolysing, anaerobic bacteria, streptococci hemolysing and non-hemolysing, staphylococci, and bacteria responsible for tooth decay (Streptococcus mutans and Lactobacillus spp.

[Association between genital mycoplasmas and risk of preterm delivery].

The main aim of this study was to determine the prevalence of maternal colonisation by genital mycoplasmas during pregnancy and to assess its association with preterm delivery. The cervical swabs of 179 pregnant women between 8 and 16 week of gestation were cultured for Mycoplasma hominis and Ureaplasma urealyticum. Clinical details and perinatal outcomes were documented.

[Diagnostic value of Gram stain for assessment of vaginal smears during pregnancy].

The main aim of this study was to compare the diagnostic value of Giemsa stained method with Gram stained method for the evaluation of vaginal smears among pregnant women. A study population comprised 111 pregnant between 6 and 30 weeks of gestation. The vaginal smears from every subject was diagnosed according to Giemsa and Gram stained method and micro-organisms were isolated by culture.

[The evaluation of prevalence and the impact of pathological microflora of the lower genital tract among women at early pregnancy on the risk of preterm delivery].

The main aim of this prospective study was to determine the prevalence and an association between pathological microflora of the lower genital tract diagnosed at early pregnancy and the risk of preterm delivery. The study group comprised 179 randomly selected pregnant women from Lodz region, between 8 and 16 week of pregnancy. For the qualitative and quantitative assessment of biocenosis of the lower genital tract vaginal and cervical swabs were collected from the pregnant women under study.

[Advances in microbiological diagnosis of infectious diseases].

Development of new methods in microbiological diagnosis of infectious diseases is described. Particularly methods which are based on techniques DNA microarray, protein microarray and nanotechnology.

[Occurrence of bacteria in the mouth from genera of Micrococcus, Kocuria, Nesterenkonia, Kytococcus and Dermacoccus].

The aim of the study was to assess the prevalence of different bacteria in the oral cavity. The bacteria were present in the oral cavities of 73 (48.7%) of 150 individuals.

[Diseases caused by hantaviruses].

Hantaviruses are RNA viruses that belong to the genus Hantavirus, family Bunyaviridae. The main reservoir of hantaviruses are rodents. Humans become infected by inhaling particles of dust contaminated with faeces of rodents, that are found In Europe and Asia hantaviruses named: Hantaan, Seoul and Dobrava-Belgrade causing haemorrhagic fever with renal syndrome (HFRS) are prevalent.

The correlation between the numbers of some bacteria in human oral cavity and blood neutrophil count.

The correlation between the number of blood polymorphonuclear granulocytes (PMNs) and the counts of oral bacteria in 92 children (33 girls and 59 boys), aged 4-15 was investigated. The groups of children comprised 44 healthy individuals and 48 children suffering from acute lymphoblastic leukaemia who were given intensive antileukaemic chemotherapy. It was found that while the number of PMNs in blood decreased, the counts of Streptococcus spp.

[The presence of staphylococci in the vagina of pregnant women].

We were investigating the colonisation rate as well as the quantity of staphylococci in the vagina of women with physiological and complicated pregnancy. We have found high frequency of staphylococci (coagulase-negative and/or coagulase-positive). Vaginal carriage rate amount 90%.

[Staphylococci and enteric rods in the oral cavity of children with acute lymphoblastic leukemia].

The frequency of isolation and the number of staphylococci and Gram-negative enteric rods in saliva were estimated in a group of 48 children of both sexes, aged 4-15 who were in the course of treatment of acute lymphoblastic leukemia (ALL). The results were compared with the same parameters in a group of 44 healthy children of the same age. Staphylococci (both coagulase-negative and coagulase-positive) were found in the oral cavities of all healthy children and of 91.

[Antagonistic properties of bacterial flora in the mouth and throat of children].

The research concerned the antagonistic activity of oral and pharyngeal bacterial flora in 44 children, of both sexes, aged 4-15. These properties were estimated basing upon in vitro inhibition of the growth of the standard indicator strains Staphylococcus aureus 209P and Escherichia coli K-12. Bacteria, both aerobic as well as anaerobic, inhibiting the growth of S.

[Some factors influencing the number of staphylococci in the mouth and throat of children].

The relationship between the count of polymorphonuclear granulocytes in blood and also between the percentage of oral and pharyngeal streptococci showing antagonistic activity on the indicator strain Staphylococcus aureus 209P and the number of staphylococci in the oral cavity and pharynx were investigated. The study comprised 92 children, of both sexes, aged 4-15; among them there were 48 children with the decreased number of circulating polymorphonuclear granulocytes due to the treatment of acute lymphoblastic leukaemia (ALL). A statistically significant negative correlation between the number of polymorphonuclear granulocytes in blood and the count of oral and pharyngeal staphylococci (both coagulase-negative and coagulase-positive) in children with ALL as well as in healthy children was revealed.

[Quantitative changes of bacterial flora from the oral cavity and throat in children with acute lymphoblastic leukemia].

Quantitative investigations were carried on aerobic and anaerobic bacterial flora of oral cavity and throat in 44 children in the age of 5-10 years with acute lymphoblastic leukemia, intensively treated with cytostatics, and in 23 healthy children which served as a control group. Samples of saliva from leukemic children revealed significantly higher than in control group--presence of aerobic bacteria, particularly streptococci and enterococci. Material from throat was differing only in regard to staphylococci.

[Antagonism between oral cavity streptococci and staphylococci].

The subject of this study was investigation of quantitative relations between streptococci, lactic acid bacilli and actinomycetes and staphylococci present in the oral cavity. It was found that in each tested sample of saliva streptococci are present which inhibit growth of an indicator strain Staphylococcus aureus 209P. Percentage of such streptococci varies from 11.

[Production of glycocalyx by coagulase negative staphylococci isolated from the oral cavity].

The study was aimed at determination whether and how frequently coagulase-negative staphylococci persisting in human oral cavity possess the same feature. The material consisted of 255 strains of coagulase-negative staphylococci isolated from oral cavity of persons of both sexes and in differing age. Glycocalyx production by these strains was tested quantitatively by a colorimetric method.

[Influence of antagonistic flora on quantity of staphylococci in the oral cavity].

The study was aimed at establishment, whether in oral cavity co-inhabit bacteria demonstrating antagonistic properties against staphylococci and whether this phenomenon may influence the size of staphylococcal population in this environment. Two locations of bacteria in oral cavity were investigated--saliva and tooth plaque. It was found that total quantity of staphylococci (both coagulase-positive and/or coagulase-negative) in saliva decreases with the age of investigated persons.