Reversal of the sex difference in plasma leptin levels in obese children with impaired glucose tolerance

INTRODUCTION: Basal leptin level has been demonstrated to correlate positively with many indices of obesity, as well as insulin resistance. However, to date, little is known about regulation of leptin in obese children with incipient glucose metabolic disorders. OBJECTIVE: The aim of this study was to define the precise influence of the glucose tolerance status on plasma leptin in obese boys and girls separately. MATERIAL AND METHODS: 70 obese children with impaired glucose tolerance (IGT) and well-matched 70 normal glucose-tolerant (NGT) subjects were examined. Fasting and 2-h post glucose load plasma glucose and insulin levels as well as fasting leptin levels were determined, apart from anthropometric measurements. RESULTS: Leptin levels were significantly lower in girls with IGT compared to NGT girl (17.7+/-6.5 microg/L vs. 23.1+/-7.7 microg/L; p<.001). No such difference was observed in boys. In a multiple regression analysis adjusting for age and adiposity, in the female group plasma glucose and insulin levels 2-h after glucose load were the best predictors of fasting plasma leptin (r=-0.49, p<.005 and r=0.34, p<.05; respectively). In boys, plasma insulin level 2-h after glucose load was the independent determinant of leptin (r=0.36, p<.05). CONCLUSION: The differences between regulation of leptin synthesis in girls and boys with simple obesity were found. The stimulatory effect of insulin on leptin synthesis was greater in girls with normoglycemia than in girls with impaired glucose tolerance.     

IVM media, oocyte diameter and donor genotype at RYR1 locus in relation to the incidence of porcine diploid oocytes after maturation in vitro

In the present study three factors were investigated that may affect the process of the first polar body extrusion in pig oocytes matured in vitro: IVM medium, oocyte diameter and donor genotype at the ryanodine receptor (RYR1) locus. In the first experiment, COCs were collected by the aspiration of slaughterhouse ovaries. Oocytes were matured in vitro at 39 degrees C, in humidified 5% CO(2) atmosphere for 44 h using the following media: (1) TCM199+hCG+eCG+follicular fluid (FF), (2) TCM199+hCG+17beta-estradiol and (3) NCSU23+hCG+eCG+FF. According to cytogenetic analysis, 98.1% of cells reached the second metaphase stage (MII). No significant differences were observed among IVM groups in terms of diploidy level. In the second experiment, oocytes collected by the aspiration or slicing of individual ovaries were matured in vitro in groups reflecting their origin. One ovary was considered a donor. IVM was carried out under conditions described in experiment I, with the use of TCM199+hCG+17beta-estradiol. A total of 68 ovaries/donors were included in this study. Granulosa cells collected from each ovary were used as DNA source in molecular (RFLP) analysis. Genotype frequencies at the RYR1 locus were as follows: CC, 0.46; CT, 0.48 and TT, 0.06. After maturation the diameter of each denuded oocyte was determined with the use of a computer aided system. Five size categories were distinguished: <90, 90-100, 100.1-110, 110.1-120 and >120 microm. The average diameter of haploid oocytes at MII stage was 111.7 microm, whereas that of diploid cells was 110.4 microm. According to statistical analysis, diploidy was not related to the oocyte diameter. That trait, however, was influenced by the donor genotype at the RYR1 locus. The TT genotype was associated with a higher rate of diploidy.     

Inhibition of zeaxanthin epoxidase activity by cadmium ions in higher plants

The effect of cadmium and zinc ions on violaxanthin cycle enzymes, violaxanthin de-epoxidase and zeaxanthin epoxidase, has been investigated on selected plant species, as well as in vitro. About 50% inhibition of zeaxanthin epoxidase by cadmium ions was found for duckweed (Lemna trisulca) and tomato (Lycopersicon esculentum) leaves but for apricot (Prunus armeniaca) leaves no cadmium inhibition of the epoxidation reaction was observed. The cadmium inhibition of zeaxanthin epoxidase in tomato was abolished by zinc ions. Zinc ions alone did not affect the activity of neither of the enzymes of the violaxanthin cycle. This suggests that mechanism of cadmium inactivation of the enzyme relies on cadmium interaction with a cysteine residue of the protein, important for the enzyme activity. The target cysteine in tomato epoxidase could be the cysteine residue present in the most conservative part of the molecule which is not present in the apricot enzyme sequence. Neither stimulation nor inhibition of violaxanthin de-epoxidase by cadmium ions both in vivo and in vitro studies was detected. It confirms the proposed mechanism of zeaxanthin epoxidation inhibition by cadmium ions because the cysteine residue in the conservative motif of violaxathin de-epoxidase is not present.     

Strains of genus Salmonella isolated from extraintestinal infections

Every year in Poland from tens to more than hundred bacteriologically verified extraintestinal infections caused by Salmonella species have been registered. These unusually located infections have substantially heavy course and in many cases hospitalisation and antibiotic therapy have to be involved. Cases of extraintestinal infections with these Gram-negative rods, which were described in the literature, concerned: pneumonias, lung abscesses and thoracic empyemas, and infections of: blood, bones and joints, wounds, fistulas and urinary tract. The aim of this study was to set extraintestinal Salmonella infections and to analyze a susceptibility of isolated strains to antimicrobial agents. Between 01.07.2002 and 31.12.2004 (30 months) 13 strains of Salmonella genus have been isolated, including 11 S. enteritidis and 2 S. Hadar. In general, with one exception, isolated strains were susceptible to tested antibiotics/chemotherapeutics. ESBL - positive strains were not detected. The tendency of Salmonella strains to cause extraintestinal infections has been noticed. The problem is still escalating, especially in group of patients chronically treated, with immunodeficiency and immunosuppression, after complicated medical procedures, also in the group of small children and aged persons. Therefore, it is necessary to evaluate a susceptibility to antibiotics/chemotherapeutics of every strain from confirmed case of Salmonella extraintestinal infection and it is important to apply a guided therapy.     

Frequency and susceptibility patterns of non-fermenting gram-negative rods isolated from patients hospitalised in intensive care units of a tertiary care hospital

The aim of the study was to assess frequency and susceptibility to antimicrobial agents of non-fermenting gram-negative rods isolated from clinical specimens obtained from patients requiring intensive care, with emphasis on profile of the unit. Identification of cultured isolates was done using automated VITEK and API systems (bioMerieux, France). Susceptibility to antimicrobial agents was tested by a disk-diffusion method according to the NCCLS recommendations. In total the analysis comprised 425 strains of non-fermenting gram-negative rods, constituting 58.9% of all isolates of gram-negative bacteria. In blood cultures predominated strains of A. baumannii (46.8%) and P. aeruginosa (40.4%), while in cultures of other clinical specimens these bacteria comprised 42.9% and 43.9% of isolates. Major differences were observed in frequency of these species on both ICU units. Strains of non-fermenting rods isolated from blood cultures comprised a lower percentage of strains susceptible to antimicrobials (particularly cefepime and carbapenems) than isolates cultured from other specimens. Strains of A. baumannii resistant to imipenem and meropenem were detected with a frequency of 12.5% and 26.7%, respectively. Resistance of P. aeruginosa strains to carbapenems was 62.2% and 44.3%, respectively. There was a relatively high percentage of strains susceptible to cefepime (82.0%), ceftazidime (78.9%), amikacin (77.8%) and piperacillin/tazobactam (69.7%). Conclusions: 1. There was a predominance (58.9%) of strains of gram-negative non-fermenting rods. 2. Isolates from blood cultures were characterised by a much higher percentage of resistant strains in comparison to other specimens. 3. Strains of A. baumannii resistant to carbapenems were recorded. 4. There were differences in frequency and antimicrobial susceptibility among the strains of P. aeruginosa and A. baumannii depending on the type of clinical specimen and ICU profile.     

Evaluation of the enzyme-linked immunosorbent assay for the serodiagnosis of tularemia

The usefulness of the ELISA using as antigen prepared in our laboratory supernatant obtained after centrifugation of sonicated F. tularensis cell suspension was compared with the tube agglutination test with commercial available antigen. Paired serum specimens obtained from 6 patients with ulceroglandular syndrome of tularemia were tested in both tests. The cut-off limit of serum antibodies was set at mean antibody titre determined in the sera of 115 blood donors exceeded by three standard deviations. Antibodies to F. tularensis in diagnostically significant titre were detected in all 12 serum samples by both tests. However the titres obtained in ELISA were several times higher than in tube agglutination test. In the second serum sample the level of IgA and IgM was lower but the level of IgG higher than in the first sample. We could not observe any difference in the level of antibodies between paired serum specimens in tube agglutination test.     

Profile of toxigenicity of Clostridium difficile strains isolated from paediatric patients with clinical diagnosis of antibiotic associated diarrhea (AAD)

This study was performed to determine profile of toxigenicity of 18 Clostridium difficile strains isolated from paeditric patients suffering from antibiotic associated diarrhea (AAD). Toxigenicity of C. difficile strains was tested for detection toxin A and toxin B by phenotypic methods and for detection of the tcdA and tcdB genes using of PCR. Changes in the repeating regions of the tcdA genes were detected with the NK9/NKV011 primer pairs. For detection of binary toxin (CDT) cdtA and cdtB genes, cdtApos/cdtArev i cdtBpos/cdtBrev two pair primers in PCR was used. Among C. difficile strains was detected three profiles of toxigenicity: C. difficile strains possesing of tcdA and tcdB genes but not possesing cdtA and cdtB genes of binary toxin (A+B+CDT-), strains possesing tcdA and tcdB and cdtA and cdtB genes (A+B+CDT+), strains with deletion of toxin A gene (A-B+CDT-). This is the first report on the occurence of binary positive C. difficile strains isolated from paediatric patients.     

Phylloclimate or the climate perceived by individual plant organs: what is it? How to model it? What for?

This review introduces the emergence of a new research topic, phylloclimate, located at the crossroads between ecophysiology and canopy microclimate research. Phylloclimate corresponds to the physical environment actually perceived by each individual aerial organ of a plant population, and is described by physical variables such as spectral irradiance, temperature, on-leaf water and features of around-organ air (wind speed, temperature, humidity, etc.). Knowing the actual climate in which plant organs grow may enable advances in the understanding of plant-environment interactions, as knowing surface temperature instead of air temperature enabled advances in the study of canopy development. Characterizing phylloclimate variables, using experimental work or modeling, raises many questions such as the choice of suitable space- and time-scale as well as the ability to individualize plant organs within a canopy. This is of particular importance when aiming to link phylloclimate and function-structure plant models. Finally, recent trends and challenging questions in phylloclimate research are discussed, as well as the possible applications of phylloclimate results.     

Lipophilic flavones of Primula veris L. from field cultivation and in vitro cultures

Ten lipophilic flavones were isolated from the leaves of Primula veris from field cultivation - the newly described 3'-hydroxy-4',5'-dimethoxyflavone and 3'-methoxy-4',5'-methylenedioxyflavone, the previously known from chemical synthesis 3',4'-dimethoxyflavone, 2',5'-dimethoxyflavone, and also flavone, 2'-hydroxyflavone, 2'-methoxyflavone, 3'-methoxyflavone, 3',4',5'-trimethoxyflavone and 5,6,2',6'-tetramethoxyflavone (zapotin) which were previously known from plants. The same flavones were found in the leaves of P. veris obtained by in vitro propagation. The structural assignments were derived from (1)H NMR, (13)C NMR, EIMS and UV spectral data and the influence of B-ring oxygen substituents on the C-2, C-3 and H-3 NMR resonances in flavones unsubstituted in the A ring is taken into consideration.     

A survey of metronidazole and vancomycin resistance in strains of Clostridium difficile isolated in Warsaw, Poland

The drug of choice used to treat Clostridium difficile-associated diarroea (CDAD) are metronidazole and vancomycin. Information about emergence of antimicrobial resistance among C. difficile strains to metronidazole and intermediate resistance to vancomycin in some countries are alarming. This study was performed to determine the susceptibility to metronidazole and vancomycin of 193 C. difficile strains isolated in our diagnostic laboratory between year 1998 and 2003 from patients adults and children suffering from CDAD. Among these strains, 142 produced toxin A and B (TcdA(+)TcdB(+)), 43 only B (TcdA(-)TcdB(+)) and 8 were nontoxigenic. We have not observed any differences in susceptibility to metronidazole and vancomycin between all C. difficile strains under investigation (toxinogenic and non-toxinogenic). Resistance to metronidazole and vancomycin was not observed.