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A Czech

Publications and source records attributed to A Czech.

At least 19 recordsLinked to original sources
PubMed2001

Prevalence of Rho-inactivating epidermal cell differentiation inhibitor toxins in clinical Staphylococcus aureus isolates.

Staphylococcus aureus produces exotoxins of the epidermal cell differentiation inhibitor (EDIN) family that ADP-ribosylate and inactivate Rho GTPases. The prevalence of genes encoding EDIN in clinical and nasal isolates of S. aureus was investigated. Of the 196 clinical S. aureus isolates tested, 15 (7.8%) were positive for 1 edin gene, whereas of 81 nasal isolates tested, only 3 (3.7%) were edin positive. Of the total 18 edin-positive isolates, 16 (90%) carried edin-B and 2 (10%) carried edin-C, but none was positive for edin-A. All edin-positive strains could produce the respective EDIN protein. Pulsed-field gel electrophoresis analysis suggested that the edin-B-positive S. aureus isolates are derived from one clone, and the edin-C-positive isolates are derived from another clone. Given that toxins acting on Rho GTPases are considered to be important for bacterial virulence, the EDIN toxins of S. aureus should receive more attention in future studies.

Adult↗
PubMed1999

[Influence of pre-conception pregnancy planning in women with diabetes mellitus I on the number of spontaneous abortions and major congenital malformations in their children].

OBJECTIVE: The study assesses the relationship between pre-conception pregnancy planning and number of spontaneous abortions and major congenital malformations in their children. MATERIALS AND METHODS: 138 pregnancies in women with type 1 diabetes without complications or only with simple retinopathy (White B, C, D) were analyzed. Women were treated in the Outpatient Family Planning Center in Warsaw between 1988 and 1998. Thirty women were planning the pregnancy prior to conception, 108 registered already when pregnant. The groups compared did not differ statistically in age, duration of diabetes or diabetic angiopathy. Mean values of HbA1C in consecutive trimesters were: 6.40%, 5.84%, 5.67% in the group of patients planning the pregnancy and 6.99%, 6.29%, 6.15% in the non-planning group. The differences were statistically significant (p < 0.05, p < 0.05, p < 0.01). RESULTS: In the pre-conception group there were no spontaneous abortions and no and major congenital malformations. Mean value of HbA1C in early pregnancy was significantly higher in women with spontaneous abortions than in the remaining women in the non-planning group (respectively 7.9% and 6.9%). Also, mean value of HbA1C in early pregnancy was significantly higher in women who gave birth to children with major congenital malformations than in women had healthy children (respectively 8.23% and 6.81%, p < 0.05). CONCLUSION: Pre-conception pregnancy planning improves metabolic control during pregnancy and decreases the rate of spontaneous abortions and major congenital malformations.

Abortion, Spontaneous↗
PubMed1997

[Prospective studies of diabetic retinopathy in a cohort of patients with type II diabetes mellitus].

To gain current data about epidemiology of diabetic retinopathy in a population of type 2 diabetics a long-term prospective study was started. The study included 1334 patients with type 2 diabetes mellitus registered in Warsaw regional Diabetes Center. The prevalence of any form of diabetic retinopathy in this group was 31.4% and proliferative retinopathy-1.3%. It was found that the patients with retinopathy had diabetes mellitus of longer duration, higher fasting and postprandial levels of glycemia and higher daily proteinuria in comparison with diabetics without retinopathy. Apart from that, a frequency of ischemic heart disease and lower extremity ischemic disease was higher in diabetics with retinopathy. 109 new cases of retinopathy were diagnosed during 3-year follow-up. The study allowed us to determine the current epidemiological parameters concerning diabetic retinopathy in type 2 diabetics and a set of parameters characterizing people at highest risk of a development of retinopathy.

Aged↗
PubMed1997

[Microcirculatory evaluation of the early diabetic foot syndrome using laser doppler].

UNLABELLED: Recognition of early microcirculatory disturbances in feet of diabetics may facilitate the pathogenic interpretation of the diabetic foot syndrome, selection of the patients at risk of developing clinical problems and serve as the base for designing the preventive measures. This could be particularly true in diabetics with peripheral neuropathy. Therefore the study aimed at the assessment of functional parameters of the foot microcirculation in IDDM patients presenting signs of peripheral neuropathy but without any symptoms of the diabetic foot syndrome was undertaken. For comparison 20 IDDM subjects with the signs of peripheral neuropathy and 10 IDDM subjects without this complication were studied both clinically and metabolically. All of them underwent the examination of microcirculation of the feet with the use of Laser Doppler Flowmeter. The parameters measured were: resting blood flow, post-occlusive, hyperemic response, flow change after heating to 44 degrees C and the flow on dependency. In IDDM subjects with peripheral neuropathy the following functional microcirculatory abnormalities were found: delay and decrease in post-occlusive, hyperemic response (4.5 +/- 1.8 s in neuropathic vs 0.5 +/- 2.4 s in non-neuropathic IDDM patients), decrease of the peak flow (36 +/- 7.0 PU in non neuropathic vs 18 +/- 5.0 PU in neuropathic IDDM patients) and also impairment of the response of the skin flow to focal heating peak flow at 44 degrees C (48 +/- 7.0 PU vs 12 +/- 3.0 PU in non neuropathic IDDM patients). Also the venoarteriolar reflex measured as the ratio of resting to standing flow in the feet skin was significantly decreased (80% in non-neuropathic versus 35% in neuropathic IDDM patients). CONCLUSION: Laser Doppler Flowmetry discovers the very early functional abnormalities in the microcirculation of the skin in the feet of IDDM with peripheral neuropathy, when none of the typical symptoms of the diabetic foot syndrome is present. It points to the significance of the relation between neuropathic and microcirculatory disturbances in the early pathogenesis of diabetic foot syndrome.

Adult↗
PubMed1997

[Diabetes mellitus as a risk factor for atherosclerosis--a reminder of the facts].

Diabetes mellitus in all its forms is the pathological state, which includes the atherogenic mechanisms of intensive action. This results in a very significant increase of the incidence, morbidity and mortality due to atherosclerotic complications. Such negative relationship is observed since decades and everywhere. Atherosclerosis is the main case of death in the subpopulation of diabetics in the degree much higher than in the general population. Therefore the studies of the mechanisms of the atherogenic influence of diabetes mellitus also of the possibility of preventive and therapeutic interventions are of utmost importance. Many of such studies are documenting, that such interventions are effective in practice. Active prevention and early individual diagnosis of atherosclerotic risk appears as the affective approach. The bare fact of such possibility was reminded in the paper.

Arteriosclerosis↗
PubMed1997

[Measurement of treatment efficacy in diabetes: effect of atherosclerosis prevention and general effects].

Numerous indirect and direct, long-term, well designate, multicenter studies are pointing to the fact, that intensification of the hypoglycemic therapy of diabetes mellitus and also the control of the non-hyperglycemic risk factors of atherosclerosis decrease the incidence, morbidity and mortality due to atherosclerosis complications in the subpopulation of diabetics type I as well as type II. This positive finding requires the objective monitoring of the quality of diabetes mellitus care. One has to be sure, that its activity exerts also the anti-atherogenic effect. The respective indices are presented using the suggestions of the experts committees of the European Association for the Study of Diabetes (EASD).

Adolescent↗
PubMed1996

Rho is a negative regulator of human monocyte spreading.

Monocyte spreading is a sequential series of events including cell flattening, formation of new actin structures and focal adhesions, as well as development of cytoplasmic projections. To investigate the involvement of the GTP-binding protein Rho in spreading, we treated human blood monocytes or PMA-stimulated U937 or THP1 cells with Clostridium botulinum C3-transferase (C3), which ADP-ribosylates and inactivates Rho in intact cells. The C3 treatment caused 1) a four- to fivefold increase in the number of THP1 cells that spread on fibronectin within 24 h of PMA stimulation, 2) a greater area covered by the spread cells, and 3) accelerated and enhanced development of macrophage-like filopodial and pseudopodial projections. Similar results were obtained with PMA-stimulated U937 cells and human blood monocytes. Furthermore, cell staining revealed disorganization of subcortical actin in C3-treated THP1 cells, whereas circular actin formations at the substrate-attached part of the cells and vinculin-containing focal complexes/adhesions were unaffected. Finally, we found a decrease in membrane-associated RhoA in normal spreading THP1 cells, which suggests endogenous inactivation of Rho and might provide an explanation for the acceleration of spreading caused by the C3-transferase. In conclusion, these results indicate that active Rho is an important, negative regulator of human monocyte spreading by maintaining cell tension and cortical actin organization.

ADP Ribose Transferases↗
PubMed1989

Mutagenicity and tumorigenicity of dihydrodiols, diol epoxides, and other derivatives of benzo(f)quinoline and benzo(h)quinoline.

The mutagenic activities of benzo[f]quinoline, benzo[h]quinoline, and a number of their derivatives, including dihydrodiols, K-region oxides, diol epoxides, and tetrahydroepoxides, were assessed in strain TA 100 of Salmonella typhimurium. The dihydrodiol derivatives of benzo[f]quinoline and benzo[h]quinoline were also tested for tumorigenic activity in newborn mice. Benzo[f]quinoline was metabolically activated in the presence of rat liver S-9 preparation to products mutagenic to the bacterial system to a greater extent than was benzo[h]quinoline. However, trans-7,8-dihydro-7,8-dihydroxybenzo[f]quinoline was less mutagenic compared to trans-7,8-dihydroxy-7,8-dihydrobenzo[h]quinoline in the presence of rat liver homogenate. The data on the mutagenic activity of the dihydrodiol derivatives of benzoquinolines were consistent with the intrinsic mutagenicity of the corresponding epoxide derivatives, in that the bay-region diol epoxides and tetrahydroepoxide of benzo[h]quinoline exhibited considerably higher mutagenic activities compared to those of the corresponding derivatives of benzo[f]quinoline at equivalent doses. The K-region oxides of benzo[f]quinoline and benzo[h]quinoline were significantly less mutagenic than their corresponding bay-region diol epoxide and tetrahydroepoxide derivatives. The demonstration that benzo[f]quinoline is significantly more mutagenic than trans-7,8-dihydro-7,8-dihydroxybenzo[f]quinoline, a precursor to the weakly mutagenic bay-region diol epoxide, suggests that the bay-region diol epoxide formation is not the principal pathway for the metabolic activation of benzo[f]quinoline to a mutagen. On the other hand, the isomeric benzo[h]quinoline appears to exert its mutagenic effect via the formation of its bay-region diol epoxide. These results indicate that the position of a nitrogen heteroatom in phenanthrene (the analogous carbocyclic aromatic hydrocarbon) not only has a marked effect on the mutagenic activities of the diol epoxide derivatives, but also can alter the metabolic activation pathways of the parent hydrocarbon. Benzo[f]quinoline, benzo[h]quinoline, and their dihydrodiol derivatives were not tumorigenic in newborn mice.

Animals↗